A. This class provides for manufacturing a semiconductor containing a solid-state device by a combination of operations wherein:
(1) no other class provides for the overall combination, and
(2) the intent is to use the electrical properties of the semiconductor in the device for at least one of the following purposes: (a) conducting or modifying an electrical current, (b) storing electrical energy for subsequent discharge within a microelectronic integrated circuit, or (c) converting electromagnetic wave energy to electrical energy or electrical energy to electromagnetic energy.
B. This class provides for a species of Class 427 operations involving:
(1) coating a substrate with a semiconductive material, or
(2) coating a semiconductive substrate or substrate containing a semiconductive region;
wherein the intent is to use the electrical properties of the semiconductor in a solid-state device for at least one of the
following purposes: (a) conducting or modifying an electrical current, (b) storing electrical energy for subsequent discharge within a microelectronic integrated circuit, or (c) converting electromagnetic wave energy to electrical energy or electrical energy to electromagnetic energy.
C. This class provides for a species of Class 216 operations involving etching a semiconductive substrate or etching a substrate containing a semiconductive region, wherein the intent is to use the electrical properties of the semiconductor in a solid-state device for at least one of the following purposes: (1) conducting or modifying an electrical current,
(2) storing electrical energy for subsequent discharge within a microelectronic integrated circuit, or
(3) converting electromagnetic wave energy to electrical energy or electrical energy to electromagnetic energy.
D. This class provides for packaging (e.g., with mounting, encapsulating, etc.) or treatment of packaged semiconductor, when not elsewhere provided, wherein there are:
(1) multiple operations having a step of permanently attaching or securing a semiconductive substrate to a terminal, elongated conductor, or support (e.g., mounting, housing, lead frame, discrete heat sink, etc.),
(2) multiple operations having a step of shaping flowable plastic or flowable insulative material about a semiconductive substrate, or
(3) a step of treating an already packaged semiconductor substrate (e.g., coating, etching, etc.); if the following conditions are also met: (a) there is significant semiconductor chip structure (e.g., such as recited semiconductor junction, etc.) or named semiconductor device (e.g., DRAM, CMOS, EPROM, etc.), or (b) there is no significant semiconductor structure if also combined with a coating operation of this class (see B above) or etching operation of this class (see C above), and (c) the intent is to use the electrical properties of the semiconductor in a solid-state device for at least one of the following purposes: (i) conducting or modifying an electrical current, (ii) storing electrical energy for subsequent discharge within a microelectronic integrated circuit, or (iii) converting electromagnetic wave energy to electrical energy or electrical energy to electromagnetic energy;
(1) Note. When Class 438 coating (see B above) or etching operations (see C above) are not included, Class 29, following historical precedence, provides for processes of mounting, packaging, molding, or encapsulating of semiconductors having no significant semiconductor chip structure (e.g., merely recited as semiconductor chip, per
se, etc.) when not elsewhere provided.
E. This is the generic class for operations not elsewhere provided for treating a semiconductive substrate or substrate containing a semiconductive region; wherein the intent is to use the semiconductor in a solid-state device for at least one of the following purposes:
(1) conducting or modifying an electrical current,
(2) storing electrical energy for subsequent discharge within a microelectronic integrated circuit, or (3) converting electromagnetic wave energy to electrical energy or electrical energy to electromagnetic energy.
(1) Note. Lacking an indication that the semiconducting material is to be used for a purpose other than (a) conducting or modifying an electrical current, (b) storing electrical energy for subsequent discharge within a microelectronic integrated circuit, or (c) converting electromagnetic wave energy to electrical energy or electrical energy to electromagnetic energy; it will be assumed that the process meets the Class 438 definition.
(2) Note. For this class certain materials will be considered to be semiconductors even if there is no other indication that semiconducting properties are present. Thus, if the criteria set forth under the (1) Note is met that there is no indication that the material is to be used for a purpose other than (a), (b), or (c), the following materials are to be considered semiconductive: silicon, germanium, selenium, tellurium, gallium nitride, gallium phosphide, gallium arsenide, aluminum phosphide, aluminum arsenide, and mercury cadmium telluride.
LINES WITH OTHER CLASSES
Several classes provide for plural step operations for manufacturing semiconductor solid-state devices or components therefor. Combined operations for manufacturing semiconductor electrical devices or semiconductor-based components therefor having plural steps not encompassed by another class are proper for Class 438.
For example, while plural steps acceptable to Class 264 (e.g., injection molding and subsequent removal of flash, etc.) remain in Class 264, combinations of molding and adhesive bonding are provided for in Class 156, even though this involves multiple steps, one of which (i.e., molding) would be considered a Class 264 unit operation even if semiconductor material is involved. However, combinations of molding, adhesive bonding, and a Class 438 unit operation acting on a semiconductor substrate which is used for at least one of the following purposes: (a) conducting or modifying an electrical current, (b) storing electrical energy for subsequent discharge within a microelectronic
integrated circuit, or (c) converting electromagnetic wave energy to electrical energy or electrical energy to electromagnetic energy, are considered proper for Class 438.
A. UNIT COATING OPERATIONS, COMBINED OPERATIONS INVOLVINGCOATING, AND PARTICLE BOMBARDMENT
The following search notes are intended to clarify the lines and distinctions for determining when coating operations are provided for in Class 438. Throughout this class, the term "coating" is used in the generic sense to include both surface coating and impregnation.
The unit coating operations in Class 438 may be viewed as a specie of a Class 427 process which was removed intact from Class 427 and transferred to Class 438 for the convenience of the searcher. Thus, plural step operations that were acceptable in Class 427 are now acceptable in Class 438 if the criteria for the semiconductor material as set forth hereinabove is met. Coating operations which do not meet the Class 438 definition may be classified in the classes identified in References to Other Classes, below.
B. UNIT ETCHING OPERATIONS AND COMBINED ETCHING OPERATIONS INCLASS 438
In References to Other Classes, below, are search notes are intended to clarify the lines and distinctions for determining when an etching unit operation is provided for in Class 438. Throughout this class, the term "etching" is used in the generic sense to include the removal of a surface by chemical reaction or solvent action regardless of the composition thereof. The unit etching operations in Class 438 may be viewed as a specie of a Class 216 process which was removed intact from Class 216 and transferred to Class 438 for the convenience of the searcher. Thus, plural step operations that were acceptable in Class 216 are now acceptable in Class 438 if the criteria for the semiconductor material as set forth hereinabove is met. Etching operations which do not meet the Class 438 definition may be found in References with Other Classes, below.
C. PACKAGING (E.G., WITH MOUNTING, ENCAPSULATING, ETC.) ORTREATMENT OF PACKAGED SEMICONDUCTOR
Packaging is a semiconductor art manufacturing term for integration, assembly, or surrounding of a semiconductive substrate (e.g., chip, die, etc.) with a permanent encasement, housing, capsule, or support. This is distinguished from package making found in Class 53 which is directed to preparing a manufactured product for passage through the channels of trade in a safe, convenient, and attractive condition, usually wrapped in a cover or in a container which is intended to be removed when the manufactured product is used.
Class 438 takes the following packaging or packaging related operations, if not elsewhere provided: (a) multiple operations having a step of permanently attaching or securing a semiconductive substrate to a terminal, elongated conductor, or support (e.g., mounting, housing, lead frame, discrete heat sink, etc.), (b) multiple operations having a step of shaping flowable plastic or flowable insulative material about a semiconductive substrate, or (c) a step of treating an already packaged semiconductor substrate (e.g., coating, etching, etc.).
However, other manufacturing classes have established historic lines with Class 438 that must be considered when determining proper placement. These lines with external classes revolve around such concepts as: whether there is significant semiconductor device structure, whether there is a unit operation or a so-called "multi-step" operation, etc. The search notes in References to Other Classes, below, are intended to clarify these established lines and to alert the searcher to other classes for related searches.
D. LINE NOTES TO OTHER MANUFACTURING OPERATIONS
See References to Other Classes, below for lines clarifying the relationship of other chemical classes to Class 438. For many of the chemical classes, inclusion of metal casting, working or deforming, or fusion bonding step is not acceptable if combined with an operation of the chemical class.
E. LOCATION OF SEMICONDUCTOR COMPOUND, COMPOSITION, OR STOCK
Class 438 does not provide for compound, composition, or stock material produced or utilized by a Class 438 process. A process of manufacture or use of a compound or composition is usually classified with the compound or composition. The process of manufacturing a semiconductor compound or composition and the formation of a semiconductor device or semiconductor junction takes combined operations to Class 438.
Also see References to Other Classes, below, identifying this section.
F. LINE TO HEATING CLASSES This class (438), will take the process of (a) heating of semiconductor material to modify the microstructure or electrical properties thereof, (b) combined operations involving heating of semiconductor material to modify the semiconductor structure or electrical properties when not provided in another class, or (c) heating of semiconductor substrates that affects only the nonsemiconductor region of the substrate when combined with other operations acceptable to Class 438 or combined with the establishment of device structure (e.g., connects, insulating regions, electrodes,
etc.).
See References to Other Classes, below, identified as heating classes.
G. LINE NOTES TO ELECTRICAL CLASSES
See References to Other Classes, below.
REFERENCES TO OTHER CLASSES
SEE OR SEARCH CLASS
29, Metal Working, especially
729+, for electrical device manufacturing apparatus, subclasses 829+ for the assembly of electrical components to an insulative base having a conductive path applied thereto, or formed thereon or therein (e.g., a printed circuit board). [See "Packaging (E.g., With Mounting, Encapsulating, Etc.)" above]
(1) Note. When Class 438 coating (see "Unit Coating Operations, Combined Operations Involving Coating" above,) or etching operations (see "Unit Etching Operations And Combined Etching Operations") are not included, Class 29, subclasses 825+, following historical precedence, provides for processes of mounting, packaging, molding, or encapsulating of semiconductors having no significant semiconductor chip structure (e.g., merely recited as semiconductor chip, per se, etc.) when not elsewhere provided. If there is no significant chip structure, Class 29 takes as original (a) adhesive bonding combined with specified metal shaping steps or (b) adhesive bonding combined with mechanical joining, either broad or specific.
(2) Note. Multistep processes for packaging semiconductors having no significant semiconductor chip structure are proper for Class 156 when they claim: (a) adhesive bonding combined with shaping of nonmetals; (b) adhesive bonding combined with broad or nominally claimed metal shaping steps; or (c) adhesive bonding including steps for assembling the parts to be bonded are proper in Class 156.
53, Package Making, for passage through the channels of trade in a safe, convenient, and attractive condition, usually wrapped in a cover or in a container. In this context of trade, Class 53 provides for methods of: (a) encompassing, encasing, or completely surrounding goods or materials with a cover made from sheet stock, (b) partially encasing or surrounding goods and materials by a partial cover made from sheet stock, (c) assembling or securing a separate closure to an aperture of a preformed receptacle to complete encasement of contents, (d) depositing articles and arranging fluent materials in preformed receptacles, (e) partial or complete shaping of a cover about an article, and other related package making processes. (See "Packaging (E.g., With Mounting, Encapsulating, Etc.)" above)
(1)
Note: If it cannot be perceived (a) whether the process is package making or (b) whether the process is manufacturing of a semiconductor device within or attached to a container, case, lead frame, heat sink, or enclosure as an integral part of the manufactured product; placement goes to Class 438 and Class 53 may be cross-referenced.
65, Glass Manufacturing, for processes of melting, shaping or forming, joining, or heat treating of glass. Glass is defined in the Class 65 definitions (Glossary) as an inorganic material generally including a glass former and having specific characteristics provided in the definition. Included in Class 65 is joining, per se, of glass to metal or glass. (See "Packaging (E.g., With Mounting, Encapsulating, Etc.)" above)
(1) Note. Class 438 takes packaging or the packaging-related operation of semiconductor devices when glass melting, glass shaping, glass forming, or glass heat treating is combined with any coating, adhesive bonding, metal casting, metal working, or deforming, metal fusion bonding or other chemical manufacturing operation.
65, Glass Manufacturing, for processes of melting, shaping or forming, joining, or heat treating of glass. Glass is defined in the Class 65 definitions (Glossary) as an inorganic material generally including a glass former and having specific characteristics provided in the definition. It is noted that both silica and elemental silicon are also included for Class 65. Thus, melting, shaping, or fusion bonding of silicon dioxide, per se, or silicon, per se, is also considered proper for Class 65. Class 65 also takes combined operations whether preparatory or subsequent to the melting, shaping or forming, joining or heat treating of glass. Included in Class 65 is joining, per se, of glass to metal, spinning, per se, of glass fibers or joining through glass melting, per se, of glass fibers to substrates such as semiconductor substrates. (see "Line Notes To Other Manufacturing Operations, " above)
(1) Note. Class 438, as the exception, takes the combination of Class 438 unit coating operation or Class 438 unit etching operation with glass melting, shaping or forming, joining, or heat treating. Moreover, Class 438 also takes the heat treating, per se, of Class 438 semiconductor material if for purposes of modifying the electrical properties thereof. Class 438 takes the mounting or packaging operation of semiconductor devices when glass melting, glass shaping, glass forming, or glass heat treating is combined with any coating, adhesive bonding, metal casting, metal working, or deforming, metal fusion bonding or other chemical manufacturing operation.
106, Compositions: Coating or Plastic,
1.05+, for metal-deposition or substrate-sensitizing compositions; subclasses 286.1+ for inorganic materials only containing at least one metal atom; subclass 286.8 for inorganic materials only; subclasses 287.1+ for silicon containing other than solely as silicon dioxide as a part of an aluminum-containing compound, and subclasses 400+ for materials or ingredients. (see "Location Of Semiconductor Compound, Composition, Or Stock" above.)
117, Single-Crystal, Oriented-Crystal, and Epitaxy Growth Processes; Non-Coating Apparatus Therefore, for processes of single crystal growth of semiconductor material upon a seed or substrate and perfecting operations combined therewith. See Class 117 definitions for examples of perfecting operations generally acceptable to Class 117. See particularly Class 117, Class Definition, (2) Note, Keywords and (3) Note, Indicative Terminology, for terms indicative of single crystal formation. Inclusion of a nonperfecting single crystal forming operation on a semiconductor substrate or producing a semiconductor product meeting the hereinabove requirements of a semiconductor material or the definition of a semiconductor substrate takes the original to Class 438, even if there is present a single crystal forming step. (Coating operation not meeting Class 438 definition)
(1) Note. When combined with single crystal formation, the following operations are acceptable in Class 438: (a) simultaneous formation of nonsingle crystalline regions intended to impart structure that will serve as a functional part of the semiconductive substrate or completed device, (b) prior or subsequent removal of a nonseed portion of the substrate in order to impart electrical device structure to the same (e.g., formation or a recess, trench, trough, ridge, mesa, stripe, etc.), or (c) prior or subsequent step acting to alter the composition of the semiconductor substrate so as to impart electrical device structure to the same. 134, Cleaning and Liquid Contact With Solids, especially
1.2, and 1.3 for processes for cleaning a semiconductor substrate including the application of electrical or wave energy to the substrate. (Etching operation not meeting the Class 438 definition)
(1) Note. If the undesirable material to be removed from the semiconductor substrate resides other than on the surface thereof, the process is to be considered gettering of the substrate and thus is proper for Class 438.
148, Metal Treatment, for unit coating operations on metal, particularly
206+, wherein there is carburization or nitriding of a metal surface by chemical reaction or diffusion of an externally supplied source of carbon or nitrogen that reacts with the
metal surface wherein the metal substrate remains as part of the coating and subclasses 240[supscrpt]+ [end supscrpt]wherein there is reactive coating of a metal substrate with an external reactant (e.g., oxygen, etc.) wherein the metal substrate remains as part of the coating. Class 148 also takes heat treatment of metallic compositions if during the heat treatment there is either a change in the internal physical structure (i.e., microstructure) or chemical properties. (Coating operation not meeting Class 438 definition)
(1) Note. Since in certain instances metallic compositions could be semiconductor material meeting the Class 438 criteria, placement will go to Class 438 over Class 148 if the material is identified or perceived as semiconductor material. If perceived, a mandatory cross is made in Class 148.
(2) Note. Reactive coating, per se, of a metal (i.e., not intended to be semiconductive) area on a semiconductive substrate (i.e., meeting the Class definition of semiconductor substrate in the Glossary) is original in Class 438. A mandatory cross is made in Class 148 if the only step is reactive coating of a metal portion of a semiconductive containing substrate.
(3) Note. Combination of Class 148 heat treatment of a metal substrate to modify or maintain the chemical property or microstructure of the metal with (a) additional manufacturing of semiconductor device structure or (b) with a Class 438 coating or etching operation takes the original to Class 438.
148, Metal Treatment,
33.1+, for semiconductor stock which must be essentially homogeneous and have at least two contiguous layers differing in the number of unbound electrons and/or differing in energy gap levels, which exhibit a junction between the layers. (see "Location Of Semiconductor Compound, Composition, Or Stock" above.)
148, Metal Treatment, for processes of heat treating metals. Class 148 takes heat treatment of metallic compositions if during the heat treatment there is either a change in the internal physical structure (i.e., microstructure) or chemical properties. Since in certain instances metallic compositions could be semiconductor material meeting the Class 438 criteria, placement will go to Class 438 over Class 148 if the material is identified or perceived as semiconductor material. If perceived, a mandatory cross is made in Class 148. (heating class) 156, Adhesive Bonding and Miscellaneous Chemical Manufacture,
60+, for a process of adhesively bonding. Multistep processes
for packaging semiconductors having no significant semiconductor chip structure are proper for Class 156 when they claim (a) adhesive bonding combined with shaping of nonmetals, (b) adhesive bonding combined with broad or nominally claimed metal-shaping steps, or (c) adhesive bonding including steps for assembling the parts to be bonded are proper in Class 156. An adhesive bonding unit operation for packaging or mounting operations on semiconductor devices goes as original to Class 156. Adhesive bonding combined with Class 438 coating of a semiconductor substrate or Class 438 etching of a semiconductor substrate places the original in Class 438. (See "Packaging (E.g., With Mounting, Encapsulating, Etc.)" above)
174, Electricity: Conductors and Insulators,
15.1, 16.3 for fluid cooling of electrical conductors or insulator, subclasses 52.1+, for housings with electric devices or mounting means, and subclasses 250 through 268 for printed circuit devices. (electrical class)
204, Chemistry: Electrical and Wave Energy, particularly
334+, for synthesis of material, such as silicon, by passing an electrical current through a fused material. See "Unit Coating Operations, Combined Operations Involving Coating," above and see elsewhere in this section for Class 204 or Class 205 coating. Or see "Unit Etching Operations And Combined Etching Operations" above for Class 204 etching and the line to Class 438. (see "Line Notes To Other Manufacturing Operations," above)
204, Chemistry: Electrical and Wave Energy, particularly see
192.32+, for sputter etching operations on semiconductor material and semiconductor containing substrates; even if the semiconductor is intended for electrical purposes. Simultaneous sputter etching and chemical etching (e.g., as when utilizing a mixture of argon and halide gas, etc.) go as original in Class 204. (Etching operation not meeting the Class 438 definition)
(1) Note. Creation of semiconductor structure, (e.g., semiconductor active region, semiconductor junction, etc.) by steps subsequent to sputter etching will go to Class 438.
204, Chemistry: Electrical and Wave Energy, for electroplating see Class 205 (i.e., which is an integral part of Class 204), and see Class 204
192.1+, for sputter coating operations involving semiconductor material or substrates including a semiconductor region, even if the intent is to use the semiconductor material for (a) conducting or modifying an electrical current,(b) storing electrical energy for subsequent discharge within a microelectronic integrated circuit, or (c) converting electromagnetic wave energy to electrical energy or electrical energy to electromagnetic energy. Class 204 will take combinations of electrolytic or sputter coating with other chemical treating operations that involve (a) preparatory treatment of the substrate (e.g., etching, cleaning, etc.) or (b) subsequent perfecting treatment of the applied coating with the following exception noted. (Coating operation not meeting Class 438 definition)
(1) Note. Creation of semiconductor structure (e.g., semiconductor active region, semiconductor junction, etc.) by subsequent treatment steps, even if limited to the Class 204 applied coating, will go to Class 438. Any subsequent operation that affects the substrate is not provided in Class 204 and is proper in Class 438. However, heat treatment of the Class 204 coating that causes interdiffusion limited to the interfacial region to perfect the bonding of the coating to the substrate is proper for Class 204.
205, Electrolysis: Processes, Compositions Used Therein and Methods of Preparing the Compositions, particularly
123+, and 157 for electrolytic coating operations on semiconductor or semiconductor devices. Class 205 is an integral part of Class 204 and follows the definitions thereof. (Coating operation not meeting Class 438 definition)
205, Electrolysis: Processes, Compositions Used Therein, and Methods of Preparing the Compositions, particularly
656, for electrolytic erosion of a workpiece of nonuniform internal electrical characteristics. Class 205 is an integral part of Class 204 and follows the definitions thereof. (Etching operation not meeting the Class 438 definition)
216, Etching a Substrate: Processes, for chemical etching processes and perfecting operations therefor, including lithos:graphic steps, of semiconductor material that is to be utilized for nonelectrical properties. (Etching operation not meeting the Class 438 definition)
(1) Note. This class provides for a species of Class 216 operations involving etching a semiconductive substrate or etching a substrate containing a semiconductive region; wherein the intent is to use the electrical properties of the semiconductor in a solid-state device for at least one of the following purposes: (a) conducting or modifying an electrical current, (b) storing electrical energy for subsequent discharge within a microelectronic integrated circuit, or (c) converting electromagnetic wave energy to electrical energy or electrical energy to electromagnetic energy.
(2) Note. Generic claims with a sole claimed specie of etching for Class 216 goes as original to Class 216. Generic claims with a sole disclosed specie of etching for Class 438
goes as original in Class 438. Generic claims with plural claimed etching specie wherein at least one of the claimed species does not belong in Class 438 goes as original in Class 216. Generic claims with plural disclosed etching specie one of which does not belong in Class 438 goes to Class 216 as original. Generic claims with no material specie claimed or disclosed goes as original in Class 216. When there is no generic claim and plural separately claimed etching specie, wherein at least one claim of which is Class 216 and one claim of which is Class 438, placement goes as original to Class 438 with a mandatory cross-reference to Class 216.
219, Electric Heating,
78.01+, for a process and apparatus for bonding by electrical current and pressure, and appropriate subclasses for electric heating of material, per se. However, inclusion of the criteria for Class 438 as set forth hereinabove takes the original to Class 438 even when electric heating is involved. (heating class) 228, Metal Fusion Bonding, appropriate subclasses for a process of fusion bonding and additional operations which are considered to be ancillary to the bonding (preheating, positioning, pretinning, etc.) of a semiconductive substrate; especially note
123.1, and 179.1+. [See "Packaging (E.g., With Mounting, Encapsulating, Etc.)" above]
250, Radiant energy, for methods not elsewhere provided of (a) using, generating, controlling, or detecting radiant energy, (b) combinations including such methods, and (c) subcombinations thereof. Particularly, see
492.2+, for processes of irradiation of semiconductor devices with no indication as to what occurs to the substrate. Class 250, subclasses 492.2+[supscrpt],[end supscrpt] generally relates to processes of exposing substrates to ion bombardment utilizing apparatus of Class 250 when limited to operating the apparatus in apparatus terms. Class 250 is also the generic home for processes of exposing substrates to ion bombardment. However, Class 438 provides for ion implantation of semiconductive substrate or substrate containing a semiconductive region and also ion implantation throughout the material mass to produce semiconductive material or to modify the semiconductive material. (Coating operation not meeting Class 438 definition)
250, Radiant Energy, for methods not elsewhere provided, of (a) using, generating, controlling, or detecting radiant energy, (b) combinations including such methods, and (c) subcombinations thereof. Particularly, see
492.2+, for processes of irradiation of semiconductor devices with no indication as to what occurs to the substrate. Class
250 subclasses 492.2+[supscrpt],[end supscrpt] generally relates to processes of exposing substrates to ion bombardment utilizing apparatus of Class 250 when limited to operating the apparatus in apparatus terms. Class 250 is also the generic home for processes of exposing substrates to ion bombardment. However, Class 438 takes chemically reactive ion etching of semiconductive substrate or substrate containing semiconductive region. (Etching operation not meeting the Class 438 definition)
250, Radiant Energy, for heating invisible radiant energy; subject matter of Class 438, per se, when no function other than heating is attributed to the process and for methods not elsewhere provided, of (a) using, generating, controlling, or detecting radiant energy, (b) combinations including such methods, and (c) subcombinations thereof. Particularly, see
492.2+, for processes of ion bombardment or irradiation of semiconductor devices, with no indication as to what occurs to the substrate. (heating class)
252, Compositions, for (a)
62.3+, for semiconductor compositions which have been uniformly doped or otherwise specialized for use as one layer which when combined with another such layer would provide an interface exhibiting barrier layer properties (e.g., as exists in Class 148, subclasses 33 through 33.6, stock wherein there is a semiconductor junction, etc.) and (b) subclasses 500+ for electrical conductive compositions. Also see the cross-reference art collection in Class 252, subclasses 950+[supscrpt],[end supscrpt] for doping agent source materials. (see "Location Of Semiconductor Compound, Composition, Or Stock" above.)
257, Active Solid-State Devices (e.g., Transistors, Solid-State Diodes), for active solid-state electronic device structure, per se. Subject matter may include one or more such devices combined with contacts or leads, or structures configured to be tested on a semiconductor chip, or merely semiconductor material without contacts or leads where the sole disclosed use is an active solid-state device. This subject matter does not include active solid-state devices combined with significant circuits. (electrical class) 264, Plastic and Nonmetallic Article Shaping or Treating: Processes, for a process (and steps perfecting same) of forming a composite by shaping a plastic or nonmetallic wherein a semiconducting containing preform is within a mold during the shaping operation (e.g., encapsulating, etc.). (See "Packaging (E.g., With Mounting, Encapsulating, Etc.)" above)
361, Electricity: Electrical Systems and Devices,
679+, for housings and mounting assemblies for electronic devices and components, and subclasses 736+ and 752+ for
modules for printed circuits or housing or chassis for printed circuit boards. (electrical class)
364, Electrical Computers And Data Processing Systems, especially
468.28, for methods of production or design of semiconductor devices or integrated circuits wherein a data processing system or calculating computer controls a specific manufacturing step, condition, or workpiece, and subclasses 490+ for the design and analysis of integrated circuits. (electrical class)
376, Induced Nuclear Reactions: Processes, Systems, and Elements, particularly
183, for a process of neutron bombardment, per se, of semiconductive material containing an element which is converted to a desired dopant by nuclear transmutation. Any combination of operations that goes beyond formation of the transmutated doped semiconductor material, per se, goes as original to Class 438 if it meets the criteria of the intent to use the electrical properties of the semiconductor in a solid-state device as set forth by the Class 438 definition. (Coating operation not meeting Class 438 definition)
376, Induced Nuclear Reactions: Processes, Systems, and Elements,
320+, for the direct conversion of the energy produced in a nuclear reaction into an electrical output by a one-step process or apparatus for accomplishing such a one-step process. (electrical class)
378, X-ray or Gamma Ray Systems or Devices, especially
34+, for X-ray or gamma-ray lithography. (electrical class) 382, Image Analysis, especially
145, for a process limited to image analysis per se in manufacturing of an integrated circuit. However, inclusion of subject matter for Class 438 remains with Class 438 even if there is a step of image analysis.
385, Optical Waveguides, particularly,
14, for a laser in integrated optical circuit, subclasses 129+ for a planar optical waveguide, and subclasses 141+ for a waveguide having a particular optical characteristic modifying chemical composition. The (13) Note of Class 385 indicates that miscellaneous manufacturing of optical wave guide devices not elsewhere provided are in Class 385. Thus, if the manufactured article is a semiconductor device, a Class 438 process controls over the Class 385 process even if an optical fiber is part of the device. (electrical class)
420, Alloys or Metallic Composition, for alloys or metallic compositions that may also exhibit semiconductor properties (e.g., gallium arsenide, etc.). (see "Location Of Semiconductor Compound, Composition, Or Stock" above.)
423, Chemistry of Inorganic Compounds, appropriate subclasses for inorganic compounds or elements used in the manufacture of semiconductor devices. (see "Location Of Semiconductor Compound, Composition, Or Stock" above.)
427, Coating Processes, for coating operations provided for in that class, particularly
457+, for a process of treating a coating with radiant energy; subclasses 487+ for polymerization of applied coating utilizing direct application of electrical, magnetic, wave, or particulate energy; subclasses 523+ for ion plating or ion implanting; subclasses 532+ for pretreatment of a substrate or posttreatment of a coated substrate utilizing electrical, magnetic, wave, or particulate energy; subclasses 569+ for deposition coating processes utilizing plasma; subclasses 580+ for deposition coating processes utilizing electrical discharge; subclass 581 for coating processes utilizing chemical liquid deposition; subclass 582 for coating processes utilizing photo-initiated chemical vapor deposition; subclasses 585+ for coating processes utilizing chemical vapor deposition; subclass 591 for deposition coating utilizing induction or dielectric heating; subclasses 592+ for deposition coating utilizing resistance heating; subclasses 595+ for deposition coating utilizing electromagnetic or particulate radiation; subclasses 598+ for deposition coating utilizing magnetic field or force; subclass 600 for deposition coating utilizing sonic or ultrasonic energy. (Coating operation not meeting Class 438 definition)
(1) Note. Class 438 provides for a specie of Class 427 operations involving (a) coating a substrate with a semiconductive material or (b) coating a semiconductive substrate or substrate containing a semiconductive region; and wherein the intent is to use the electrical properties of the semiconductor in a solid state device for at least one of the following purposes: (i) conducting or modifying an electrical current, (ii) storing electrical energy for subsequent discharge within a microelectronic integrated circuit, or (iii) converting electromagnetic wave energy to electrical energy or electrical energy to electromagnetic energy.
(2) Note. Generic claims with a sole claimed specie of coating for Class 438 goes as original to Class 438. Generic claims with a sole disclosed specie of coating for Class 438 goes as original in Class 438. Generic claims with plural claimed coating species wherein at least one of the claimed species does not belong in Class 438 goes as original in Class 427. Generic claims with plural disclosed coating species one of which does not belong in Class 438 goes to
Class 427 as original. Generic claims with no material species claimed or disclosed goes as original in Class 427. When there is no generic claim and plural separately claimed coating specie, wherein at least one claim of which is Class 427 and one claim of which is Class 438, placement goes as original to Class 438 with a mandatory cross-reference to 427. 428, Stock Material or Miscellaneous Articles, appropriate subclasses for semiconductor stock material defined in terms of composition and structure, especially
620,. (see "Location Of Semiconductor Compound, Composition, Or Stock" above.)
429, Chemistry: Electrical Current Producing Apparatus, Product, and Process, especially
7, for a combination including a nonbattery electrical component electrically connected within a cell casing other than testing or indicating components. (electrical class)
430, Radiation Imagery Chemistry: Process, Composition, or Product Thereof, particularly for initial lithos:graphic processes in semiconductor manufacture limited to (a) exposure imaging and developing and including preparatory operations to the exposure (e.g., as coating to form the resist, etc.) or (b) developing, per se, of subject matter of Class 430 substrates. When Class 430 exposure, imaging or developing are combined with etching or coating of a semiconductor substrate for purposes other than masking and commensurate with the Class 438 definition for manufacture of a semiconductor device as set forth hereinabove, the combination goes as original to Class 438 with the following exception noted. (Coating operation not meeting Class 438 definition)
(1) Note. Since Class 430 provides for processes of (a) coating, per se, of substrates, with a composition to produce a product to be used for electric or magnetic imagery and (b) processes of coating, per se, of substrate with a photosensitive composition for use in radiation imagery, coating or etching of semiconductor material limited to forming a product intended to be used for electric, magnetic, or radiation imagery is original in Class 430.
(2) Note. Although technically classifiable as an original in Class 438 according to the above paragraph, any multistep process involving significant Class 430 operations as a subcombination of the overall process should be cross-referenced to Class 430.
430, Radiation Imagery Chemistry: Process, Composition, or Product Thereof, particularly for initial lithos:graphic processes in semiconductor manufacture limited to (a) exposure imaging and developing and including preparatory operations to the exposure (e.g., as coating to form the
resist, etc.) or (b) developing, per se, of subject matter of Class 430 substrates. When Class 430 exposure imaging or developing are combined with etching or coating of a semiconductor substrate commensurate with the Class 438 definition for manufacture of a semiconductor device as set forth hereinabove, the combination goes as original to Class 438 with the following exception noted. (Etching operation not meeting the Class 438 definition)
(1) Note. Since Class 430 provides for processes of (a) coating, per se, of substrates, with a composition to produce a product to be used for electric or magnetic imagery and (b) processes of coating per se of substrate with a photosensitive composition for use in radiation imagery, coating or etching of semiconductor material limited to forming a product intended to be used for electric, magnetic, or radiation imagery is original in Class 430.
(2) Note. Although technically classifiable as an original in Class 438 according to the above paragraph, any multistep process involving significant Class 430 operations as a subcombination of the overall process should be cross-referenced to Class 430.
432, Heating, for generic heating processes. However, inclusion of the criteria for Class 438 as set forth hereinabove takes the original to Class 438 even when generic heating is involved. (heating class) 439, Electrical Connectors, appropriate subclasses for features related or analogous to electrical contact or housing features of active solid-state devices (e.g.,
271+, for sealing elements or subclasses 449+ for stress relief means for conductor to terminal joint. (electrical class)
501, Compositions: Ceramic, appropriate subclasses for ceramic compositions used in semiconductor devices. (see "Location Of Semiconductor Compound, Composition, Or Stock" above.)
330, for processes of manufacturing from high temperature (i.e., above 30 degrees Kelvin) superconductive material (a) superconductor devices or (b) semiconductor devices having superconductive components or connect lines. (see "Line Notes To Other Manufacturing Operations," above)
GLOSSARY:
Listed below are: (1) a compilation of acronyms, abbreviations, and technological terms pertaining to solid-state electrical devices, manufacturing processes, and related apparatus and compositions useful therefor and (2)
the meaning to be given to the various "art" terms appearing in this class. These latter terms, some of which have been included in the glossary below, are the same as that generally accepted or in common usage. However, certain terms employed in this class and also included below have been assigned definitions which may be more restrictive or different from those in common usage since these terms are being utilized for distinguishing this class over other classes of related art.
(a)static induct. thyristor or (b)static induct. trans. SLM
spatial light modulator
SLS
strained layer superlattice
SLT
solid logic technology
SMT
surface mount technology
SOG
spin-on glass
SOI
silicon on insulator SOIC
small outline IC package
SOJ
small outline J-lead package
SOS
silicon on sapphire
SPE
solid phase epitaxy
SPOT
self-aligned planar oxidation technology
SPT
substrate plate trench capacitor
SQUID
superconductive quantum interference device
SRAM
static random access memory
SRO
stress relief oxide
SSDP
simultaneous single/polycrystalline deposition
SSI
small scale integration
SST (a)super self-alignment tech. or (b)sealed sidewall tech.
STT
stacked transistor capacitor cell
SUBHET
superconducting base hot electron transistor
SUBSIT
superconducting base semiconductor isolated transistor
SWAMI
sidewall masked isolation
TAB
tape automated bonding
TAT turn around time
TBES
tritertiarybutoxyethoxysilane
TBCO
thallium bismuth copper oxide (a HTSC)
TCE
trichloroethylene
TCM
thermal conduction module
TCO
transparent conductive oxide TDDB
time dependent dielectric breakdown
TEC
thermoelectric cooler
TED
transient enhanced diffusion
TEG
(a) triethylgallium or (b) test element group
TEM
transmission electron spectroscopy
TEOS
tetraethylorthosilane TFR
thin film resistor
TFT
thin film transistor
TGZM
temperature gradient zone melting
TH
through-hole
TIBA
triisobutylaluminum
TLTR transmission line tap resistor (test structure)
TMA
(a) trimethylaluminum or (b) trimethylantimony
TMAH
tetramethyl ammoniumhydroxide
TMAT
tetramethylamidotitanium
TMB
tetramethylborate
TMCTS
tetramethylcyclotetrasiloxane
TMG trimethylgallium
TMOS
tetramethyloxysilane
TMP
trimethylphosphine
TMS
tetramethylsilane
TMT
tetramethyltin
TOFER
topos:graphic feature enhancement by RIE
TPF thermoplastic film
TRAPPAT
trapped plasma avalanche tunnel transit (diode)
TSD
temperature sensing diode
TSOP
thin small outline package
TTL
transistor-transistor logic
UHV
ultrahigh vacuum UV
ultraviolet
VCNR
voltage controlled negative resistance
VGF
vertical gradient freeze (also VFG)
VHSIC
very high speed integrated circuit
VLE
vapor levitation epitaxy
VLSI
very large scale integration VMOS
vertical MOS
VPE
vapor phase epitaxy
VSIS
V-channel substrate inner stripe
WSI
wafer scale integration
XRD
x-ray diffraction
YBCO yttria barium copper oxide (a HTSC)
YSZ
yttria stabilized zirconia
ZDO
zero drain overlap
ZIP
zigzag-in-line package
ZMR
zone melt recrystallization
mc
microcrystalline
p high resistivity intrinsic semiconductor
ACCEPTOR IMPURITY
An atom or ion different from or foreign to, but present in, a semiconductor material and which has insufficient valence electrons to complete the normal bonding arrangement in the semiconductor crystal structure. An acceptor impurity (also referred to as p-type) accepts an electron from an adjacent atom to create a positive charge carrier (i.e., a hole). A donor impurity (also referred to as n-type) provides an electron to the conduction band of the semiconductor.
ACTIVE SOLID-STATE DEVICE
An electronic device or component that is primarily made up of solid materials, usually semiconductors, which operates by the movement of charge carriers - electrons or holes - which undergo energy level changes within the material and can modify an input voltage to achieve rectification, amplification, or switching action. Active solid-state electronic devices include diodes, transistors, thyristors, etc., but exclude pure resistors, capacitors, inductors, or combinations solely thereof. The latter category is characterized as passive.
ALLOY JUNCTION
A fused junction produced by combining one or more elemental impurity metals with a semiconductor. Typical alloyed
junctions include indium-germanium and aluminum-silicon.
AUTODOPING
The introduction via the vapor phase of impurities from an existing substrate region (and adjacent supports, e.g., susceptors, etc.) into another substrate region, typically during growth of the same.
AVALANCHE BREAKDOWN
A sudden change from high dynamic electrical resistance to very low dynamic resistance in a reverse biased semiconductor device (e.g., a reverse biased junction between p-type and n-type semiconductor materials) wherein current carriers are created by electrons or holes which have gained sufficient speed to dislodge valence electrons. Avalanche breakdown can cause structural damage to a semiconductor device. BAND GAP
The difference between the energy levels of electrons bound to their nuclei (valence electrons) and the energy levels that allow electrons to migrate freely (conduction electrons). The band gap depends on the particular semiconductor involved.
BARRIER REGION OR LAYER
A region which extends on both sides of a semiconductor junction in which all carriers are swept away from the junction region. The region is depleted of carriers. This is also referred to as a depletion region. Not to be confused with diffusion barrier layers associated with metallization schemes for active solid state devices.
BINARY COMPOUND
A substance that always contains the same two elements in a fixed atomic ratio.
BIPOLAR
An active solid-state electronic device in which both positive and negative current carriers are used to support current flow.
BIPOLAR TRANSISTOR
An active solid-state electronic device with a base electrode and two or more junction electrodes in which both positive and negative current carriers are used to support current flow.
BIRD'S BEAK
The lateral encroachment of the localized oxidation region associated with a recessed oxide isolation structure.
BONDING PAD
A metallized area to which an external electrical connection is to be made.
BREAKDOWN
A sudden change from high dynamic electrical resistance to a very low dynamic resistance in a reverse biased semiconductor device (e.g., a reverse biased junction between p-type and n-type semiconductor materials) wherein reverse current increases rapidly for a small increase in reverse applied voltage, and the device behaves as if it had negative electrical resistance.
CAPACITOR
A component used in electrical and electronic circuits which stores a charge of electricity, usually for very brief periods of time, with the ability to rapidly charge and discharge. A capacitor is usually considered a passive component since it does not rectify, amplify, or switch and because charge carriers do not undergo energy level changes therein, although some active solid state devices function as voltage variable capacitors.
CHANNEL
A path for conducting current between a source and drain of a field effect transistor.
CHANNEL STOP
Means for limiting channel formation in a semiconductor device by surrounding the affected area with a ring of highly doped, low resistivity semiconductor material. In a field effect transistor, it is a region of highly doped material of the same type as the lightly doped substrate used to prevent leakage paths along the chip surface from developing. Also referred to as "chanstop."
CHANNEL PINCH-OFF REGION The location in a current channel portion of a field effect transistor (FET) where the current is reduced to a minimum value due to its diameter being reduced to a minimum.
CHARGE CARRIER
A mobile conduction electron or hole in a semiconductor.
CHARGE CONFINEMENT
Restriction of electrical charge carriers (e.g., electrons or holes) to specified locations (e.g., by quantum wells, gate
electrode potentials, etc.).
CHARGE INJECTION DEVICE
A field effect device in which storage sites for packets of electric charge are induced at or below the surface of an active solid-state device by an electric field applied to the device and wherein carrier potential energy per unit charge minima are established at a given storage site and such charge packets are injected into the device substrate or into a data bus. This type device differs from a charge transfer device in that, in the latter, charge is transferred to adjacent charge storage sites in a serial manner, whereas, in a charge injection device, the charge is injected in a nonserial manner to the device substrate or to a data bus.
CHIP
A single crystal substrate of semiconductor material on which one or more active or passive solid-state electronic devices are formed. A chip may contain an integrated circuit. A chip is not normally ready for use until packaged and provided with external connectors.
CHIP CARRIER
A package with terminals, for solid-state electronic devices, including chips which facilitates handling of the chip during assembly of the chip to other electronic elements. CLADDING BARRIER
A higher band gap material which encases a lower band gap material that defines the walls of a quantum well.
COHERENCE LENGTH
The typical distance an electron can travel before it is scattered (e.g., by a phonon, a defect, or an impurity, etc.).
COHERER
A term which encompasses both active and passive type devices, the passive type being a resistor whose resistance decreases when subjected to a high frequency signal, and the active type being a rectifier which is made up of active solid-state particles which conduct and rectify current when connected into a cohesive element but which loses that characteristic when the particles are separated (e.g., by shaking a container in which the particles are located, etc.).
COLLECTOR DIFFUSION ISOLATION (CDI)
An electrical isolation technology used for bipolar devices which employs an epitaxial layer, which forms transistor base
regions, laid on a substrate of the same conductivity type (p or n) as the epitaxial layer, with an opposite conductivity type region, more heavily doped than the epitaxial base layer and located between the layer and the substrate, forming the collector and isolating the transistor from the substrate.
COMPOUND SEMICONDUCTOR
A semiconductor composed of a chemical compound formed of elements from two or more different groups of the chemical periodic chart (e.g., Group III (B, Al, Ga, In) and Group V (N, P, As, Sb) for the following compounds: AlP, AlAs, AlSb, GaP, GaAs, GaSb, InP, InAs, and InSb, or a compound of silicon and carbon (SiC)).
CONDUCTION BAND A partially filled energy band in which electrons can move freely, permitting a material to carry electric current where electrons are the current carriers.
CONDUCTION ELECTRONS
In a conductor or n-type semiconductor, outer shell electrons that are bound so loosely that they can move freely in the conduction band of a solid material under the influence of an electric field.
CONNECTOR AREA
That portion of the electrical conductors (e.g., bonding pad, die bond, etc.) used for providing external electrical connections from a component to a chip or other component.
CONTACT
The point or part of a conductor which touches another electrical conductor or electrical component to carry electrical current to or from the conductor or electrical component.
CRYSTAL DEFECT
Any nonuniformity in a crystal lattice. There are four categories of crystal defects: (a) point defects, (b) line defects, (c) area defects, and (d) volume defects. Point defects include any foreign atom at a regular lattice site (i.e., substitutional site) or between lattice sites (i.e., interstitial site), antisite defects in compound semiconductors (e.g., Ga in As or As in Ga), missing lattice atoms, and host atoms located between lattice sites and adjacent to a vacant site (i.e., Frenkel defects). Line defects, also called edge or screw dislocations, include extra planes of atoms in a lattice. Area defects include twins or twinning (i.e., a change in crystal orientation across a lattice) and grain boundaries (i.e., a transition between crystals having no particular positional orientation
to one another). Volume defects include precipitates of impurity or dopant atoms caused by volume mismatch between a host lattice and precipitates.
DEEP DEPLETION
The condition in which a depletion layer formed in a MOS active device due to voltage applied to the gate electrode of the device is deeper than the maximum depth at which inversion would normally be expected to occur at room temperature in a semiconductor device at the surface closest to the gate electrode, without formation of an inversion layer. DEEP LEVEL CENTERS
Energy levels that can act as traps located in the forbidden band of a semiconductor material that are not near the conduction or valence band edges.
DEGENERATION
Doping of a semiconductor to such an extent that the Fermi level lies within the conduction band (i.e., N+ semiconductor) or within the valence band (i.e., P+ semiconductor). Also, in circuit applications, negative feedback between two or more active solid-state devices.
DEPLETION MODE
The operation of a field effect transistor having appreciable channel conductivity for zero gate-source voltage and whose channel conductivity may be increased or decreased according to the polarity of the applied gate-source voltage, by changing the gate-to-source voltage from zero to a finite value, resulting in a decrease in the magnitude of the drain current.
DEPLETION REGION
The region extending on both sides of a reverse biased semiconductor junction in which free carriers are removed from the vicinity of the junction. It is also called a space charge region, a barrier region, or an intrinsic semiconductor region.
DEVICE (ACTIVE)
The physical realization of an individual electrical element in a physically independent body which cannot be further divided without destroying its stated function. Examples are transistors, pnpn structures, and tunnel diodes.
DIE
A tiny piece of semiconductor material, separated from a semiconductor slice, on which one or more active electronic components are formed. Sometimes called a chip.
DIE BOND
Attachment of a semiconductor chip to a substrate or chip carrier or package, usually with an epoxy, eutectic, or solder alloy.
DIFFUSED JUNCTION
A junction between two different conductivity regions within a semiconductor and which is formed by diffusion of appropriate impurity atoms into the material.
DIFFUSION BARRIER
An obstacle to the diffusion of atoms in a metallization scheme for an active solid-state device.
DIODE ISOLATION
A technique in which a high electrical resistance between an integrated circuit element and its substrate is achieved by surrounding the element with a reverse biased pn junction.
DIP (DUAL IN-LINE PACKAGE)
A chip carrier or package consisting of a plastic or ceramic body with two rows of vertical leads in which a semiconductor integrated circuit is assembled and sealed. The leads are typically inserted into a circuit board and secured by soldering.
DIRECT BAND GAP SEMICONDUCTOR A semiconductor in which an electron transition from the conduction to the valence band, or vice versa, does not require a change in crystal momentum for electrons. Gallium arsenide is an example of a direct band gap semiconductor.
DISORDERED
Crystalline arrangement in which the different constituent atoms of a compound semiconductor randomly occupy lattice sites.
DISLOCATION
A line defect in a crystal, either of the edge type or screw type, in which the atoms are not arranged in a perfect latticelike structure. See CRYSTAL DEFECT for other examples of crystalline defects.
DMOSFET
Depletion-type metal oxide semiconductor field effect transistor. Such devices are normally in the on condition
with no applied gate voltage.
DONOR IMPURITY
An element which when added to a semiconductor provides unbound or free electrons to the semiconductor which may serve as current carriers. Typically, donors are atoms which have more valence electrons than the atoms of the semiconductor material into which they are introduced in small quantities as an impurity or dopant. Since such donor impurities have more valence electrons than the semiconductor, a semiconductor doped with donor impurities is an n-type semiconductor.
DOPANT
An impurity added from an external source to a material by diffusion, coating, or implanting into a substrate, such as changing the properties thereof. In semiconductor technology, an impurity may be added to a semiconductor to modify its electrical properties or to a material to produce a semiconductor having desired electrical properties. N-type (negative) dopants (e.g., such as phosphorus for a group IV semiconductor) typically come from group V of the periodic table. When added to a semiconductor, n-type dopants create a material that contains conduction electrons. P-type (positive) dopants (e.g., such as boron for a group IV semiconductor) typically come from group III and result in conduction holes (i.e., vacancies in the electron shells). DOPING OF SEMICONDUCTOR
Adding controlled amounts of conductivity modifying material, referred to as electrically active dopant or impurity, to a semiconductor material or to a material to produce a semiconductor having desired electrical properties for this class.
DOPING PROFILE
The point to point concentration throughout a semiconductor of an impurity atom doped into the semiconductor.
DOUBLE-DIFFUSED MOS (DMOS)
A metal oxide semiconductor having diffused junctions in which successive diffusions of different impurity types are made in the same well-defined region of the semiconductor.
DRAIN
The electrode of a field effect transistor which receives charge carriers which pass through the transistor channel from the source electrode.
DUAL GUARD-BAND ISOLATION
A type of electrical isolation of functional elements of an integrated circuit comprised of two distinct unused areas of chip surface area adjacent to the elements desired to be electrically isolated.
DYNAMIC RANDOM ACCESS MEMORY (DRAM) Solid-state memory in which the information decays over time and needs to be periodically refreshed.
ELECTROMIGRATION
Mass transport of ions (i.e., usually metal) in a material as a response to the passage of current through the material by momentum exchange between thermally activated ions and conduction electrons.
ELECTRON-HOLE PAIR
A positive charge carrier (i.e., hole) and a negative charge carrier (i.e., electron) considered together as being created or destroyed as part of one and the same event.
ENHANCEMENT MODE
The operation of a field effect transistor which has a channel formed therein between its source and drain regions and which normally does not conduct current through its channel with zero voltage applied to its gate electrode. Voltage of the correct polarity will accumulate minority carriers in the channel to permit conduction of current in the channel, thus turning on the transistor.
EPITAXIAL LATERAL OVERGROWTH
Process of epitaxial deposition through an exposed opening in an insulating layer with deposition continuing epitaxially over the insulating layer laterally from the opening.
EPITAXY
The controlled growth of a single crystal of one material on the surface of a crystal of the material (i.e., homo) or onto another substance (i.e., hetero) so that the crystal lattice of the base material controls the orientation of the atoms in the grown single crystal layer.
ESAKI DIODE A heavily doped pn-junction diode where conduction occurs through the junction potential barrier due to a quantum mechanical effect even though the carriers which tunnel through the potential barrier do not have enough energy to overcome the potential barrier. Esaki tunneling involves a tunneling barrier formed by a macroscopic depletion layer between n-type and p-type regions. It does not involve a resonant tunneling barrier using controlled quantum
confinement, a layer located between junctions, nor a thin superlattice layer.
EXTRINSIC SEMICONDUCTOR
A semiconductor whose charge carrier concentration and, therefore, electrical properties depend on impurity atoms introduced therein.
FACE BONDED
A chip mounting technique wherein semiconductor chips are provided with small mounting pads, turned face down, and bonded directly to conductors on a substrate.
FIELD EFFECT TRANSISTOR (FET)
A unipolar transistor in which current carriers are injected at a source terminal and pass to a drain terminal through a channel of semiconductor material whose conductivity depends largely on an electric field applied to the semiconductor from a control electrode. There are two main types of FETs, a junction FET and an insulated-gate FET. In the junction FET, the gate is isolated from the channel by a pn-junction. In an insulated-gate FET, the gate is isolated from the channel by an insulating layer so that the gate and channel form a capacitor with the insulating layer as the capacitor dielectric.
FIELD OXIDE
A thin (on a macroscopic scale) film made of an oxide of a material which overlies a device substrate to reduce parasitic capacitive coupling between conductors overlying the oxide and the substrate or devices below the oxide layer (e.g., in the substrate). See bird's beak.
FLIP-CHIP
A term which describes the situation wherein a semiconductor device which has all terminations on one side thereof in the form of bump contacts, has a passivated surface, and has been flipped over and attached to a matching substrate. FLOATING DIFFUSION
A region of a semiconductor device in which impurity atoms have been doped and which is electrically floating, that is, has no direct electrical connection.
FLOATING GATE
A gate electrode that is electrically floating, that is, has no direct electrical connection.
FORBIDDEN ENERGY BAND
The energy band of a material which is located between a solid material's conduction and valence bands. It is defined by the amount of energy that is needed to release an electron from its valence band to its conduction band. Electrons cannot exist in this gap. They are either below it, and bound to an atom, or above it, and able to move freely.
FRAME TRANSFER CCD
A charge coupled device area imager array with a separate image area, storage area, and read-out register area, the storage area being located between the image area and the readout area. This is distinguished from an interline- transfer CCD in which the sensing and storage/readout function areas are located next to each other.
GATE
The control electrode or control region that exerts an effect on a semiconductive region directly associated therewith, such that the conductivity characteristic of the semiconductor region is altered in a temporary manner, often resulting in an on-off type switching action. The control electrode or control region of a field effect transistor is located between the source and drain electrodes, and regions thereof.
GATE ARRAY A repeating geometric arrangement of groups of active solid-state devices, each group being connectable into a logic circuit, in one integrated, monolithic semiconductor chip.
GATE CONTROLLED DIODE
A three terminal semiconductor diode with the ability to be turned on or off by a pulse applied to its gate electrode.
GETTERING
The elimination or reduction of unwanted constituents (i.e., impurities) or defects from a substrate.
GRAPHOEPITAXY
The growth of a single crystalline layer across the surface of a nonsingle crystalline substrate by commencing growth at a seeding portion/region thereof.
GUNN DIODE
A diode in which electrons under the influence of sufficiently high electric fields are transferred between energy valleys of different momentum in the conduction band of the active semiconductor device material or holes under the influence of sufficiently high electric fields are
transferred between energy valleys of different momentum in the valence band of the active semiconductor device material. A Gunn diode does not normally have a pn junction and cannot be used as a rectifier.
GUNN EFFECT
An intervalley transfer effect wherein electrons under the influence of sufficiently high electric fields are transferred between energy valleys of different momentum in the conduction band of the active semiconductor device material, or holes under the influence of sufficiently high electric fields are transferred between energy valleys of different momentum in the valence band of the active semiconductor device material. HALL EFFECT DEVICE
An active solid-state device in which a current is flowing and is in a magnetic field perpendicular to the current, and in which a voltage is produced that is perpendicular to both the current flow direction and the magnetic field direction.
HETEROJUNCTION/HETEROINTERFACE
An interface between two dissimilar semiconductor materials. For example, one material may by InAs and the other may be InAlAs, or one material may be GaAs and the other material may be GaAlAs.
HIGH ELECTRON MOBILITY TRANSISTOR (HEMT)
A heterojunction field effect transistor with impurity ions located on the side of the heterojunction with lower affinity for the charge carriers (holes or electrons) injected at the source that pass to the drain via a channel adjacent the heterojunction.
HOLE
An empty energy level in the valence band of a semiconductor crystal which exhibits properties of a real particle and can act as a mobile positive-charge carrier.
HOMOJUNCTION
An interface between regions of opposite polarity in the same semiconductor material.
HOT CARRIER DIODE
A diode in which electrons (or holes) have energies greater than those that are in thermal equilibrium with the material of at least one of the regions forming the diode. Schottky barrier diodes typically have "hot carriers" (hot electrons) injected into the metal from the semiconductor.
HYBRID CIRCUIT
A small printed circuit having miniature components which may include passive components (resistors, capacitors, and inductors) deposited on a printed circuit board.
IMPURITY
A foreign material present in a semiconductor crystal, such as boron or arsenic in silicon, which is added to the semiconductor to produce either p-type or n-type semiconductor material, or to otherwise result in material whose electrical characteristics depend on the impurity dopant atoms.
INDIRECT BAND GAP SEMICONDUCTOR
A semiconductor material in which a change in semiconductor crystal momentum for an electron is required when it moves from the conduction band to the valence band and vice versa. Silicon and aluminum arsenide are examples of indirect band gap semiconductors.
INSULATED-GATE FIELD EFFECT TRANSISTOR (IGFET)
A unipolar transistor with source, gate, and drain regions and electrodes, in which conduction takes place in a channel controlled by action of the voltage applied to the gate electrode of the device, in which the gate electrode is separated from the channel by an insulator layer.
INSULATOR
A material which has a high resistance to the flow of electric current. It has such low electrical conductivity that the flow of current therethrough can usually be neglected.
INTRINSIC CONCENTRATION The number of minority carriers in a semiconductor due to thermal generation of electron-hole pairs.
INVERSION
A condition in a semiconductor material in which the concentration of minority carriers exceeds the concentration of majority carriers.
INVERSION LAYER/CHANNEL
A region in a semiconductor material in which the concentration of minority carriers exceeds the concentration of majority carriers.
ISOELECTRONIC
A condition in which two constituents have the same number of valence electrons.
ISOLATION
The separation or surrounding of active semiconductor regions or components with electrically insulative regions to prevent the flow of electrical current between the active semiconductor regions or between electronic component parts of a solid-state electronic device.
ISOPLANAR CMOS
A semiconductor device in which relatively thick regions of silicon dioxide, recessed into the semiconductor surface, are used to electrically isolate device areas and prevent parasitic device formation. More commonly called LOCOS CMOS.ISOPLANAR ISOLATION
A type of electric isolation in which relatively thick regions of silicon dioxide, recessed into the semiconductor surface, are used to electrically isolate device areas and prevent parasitic device formation. More commonly called LOCOS ISOLATION.
JUNCTION BARRIER
The opposition to the diffusion of majority carriers across a pn junction due to the charge of the fixed donor and acceptor ions.
JUNCTION CAPACITANCE
The capacitance across a pn junction. It depends on the width of the depletion layer, which increases with increased reverse bias voltage across the junction.
JUNCTION ISOLATION
Electrical isolation of devices on a monolithic integrated circuit chip using a reverse biased junction diode to establish a depletion layer that forms the electrical isolation between devices.
JUNCTION RESISTANCE
The electrical resistance across a semiconductor PN junction.
LAND
The conductive areas, normally metal patterns, on a semiconductor integrated circuit, which form part of the contacts and interconnections between components on the integrated circuit. See bonding pad, die bond.
LIFT-OFF
Process for the removal of unwanted deposited material from a substrate (and thus patterning the same) by the dissolution of an intermediate layer and the commitant physical separation of the overlying deposited material.
LUMINESCENCE
The emission of visible or invisible radiation unaccompanied by high temperature by any substance as a result of absorption of exciting energy in the form of photons, charged particles, or chemical change. It is a general term which includes fluorescence and phosphorescence. Types include hemiluminescence, bioluminescence, photoluminescence, electroluminescence, photoluminescence, and triboluminescence. Active solid-state luminescent devices are semiconductors which operate via injection luminescence. Active devices include pn junctions (including heterojunctions), Schottky barrier junctions, metal-insulator-semiconductor (MIS) structures, and high speed traveling domains (e.g., Gunn domain and acoustoelectric wave generated domains). Passive solid-state electroluminescent devices (phosphors) are insulators which operate in an intrinsic luminescence phenomena (i.e., where an applied electric field generates free carriers) to initiate the light emission mechanism, there being no free carriers in an insulator to be accelerated by an applied field unless the field also generates them.
MAJORITY CARRIER
The predominant charge carrier in a semiconductor. Electrons are majority carriers in n-type semiconductors. Holes are majority carriers in p-type semiconductors.
MASTERSLICE ARRAY/MASTERCHIP
A substrate that contains active and passive electronic components in a predetermined pattern which may be connected into different logic or analog circuits.
MBM JUNCTION
Active solid-state devices having metal-barrier-metal layer junctions.
METAL-OXIDE SEMICONDUCTOR FIELD EFFECT TRANSISTOR (MOSFET) See Insulated-gate Field Effect Transistor.
METALLIZATION
Process of coating (a) metal or (b) other material which is identified as having the conductive characteristic of a metal onto a semiconductor or a substrate containing semiconductor
regions to form electrodes, contacts, interconnects, bonding pads, or heat sinks and also including formation of conductive material by doping of nonconductive material.
MIM DIODE
A junction diode with a thin insulating layer of material sandwiched between two metallic surface layers which operates as a tunneling (direct or Fowler-Nordheim type) diode.
MINORITY CARRIER
The less predominant charge carrier in a semiconductor. In a p-type semiconductor, minority carriers are electrons, whereas in n-type semiconductor material, minority carriers are holes.
MIS
Acronym for metal-insulator-semiconductor. Typically active solid-state devices with MIS technology have a silicon dioxide layer formed on a single crystal silicon substrate. A polysilicon conductor layer is formed on the oxide.
MOBILITY
The facility with which carriers move through a semiconductor when subjected to an applied electric field. Electrons and holes typically have different mobilities in the same semiconductor. MODFET
Acronym for a modulation doped field effect transistor. A high speed semiconductor FET in which dopant atoms containing semiconductor layers alternate with nondoped semiconductor layers, so that the carriers (electrons or holes) resulting from the dopant atoms can travel in the undoped material, so that there is little scattering of carriers from dopant atoms. Typically, the dopant atoms are in semiconductor material having a lower carrier affinity than the undoped layers to facilitate carrier spill over into the undoped layers. Such a structure may typically constitute a superlattice. See also High Electron Mobility Transistor.
MONOLITHIC DEVICE (E.G., IC, ETC.)
A device in which all components are fabricated on a single chip of silicon. Interconnections among components are provided by means of metallization patterns on the surface of the chip structure, and the individual parts are not separable from the complete circuit. External connecting wires are taken out to terminal pins or leads.
MSM
Acronym for metal-semiconductor-metal semiconductor device.
Active solid-state semiconductor devices having a semiconductor layer sandwiched between two layers of metal and forming back-to-back Schottky diodes.
NEGATIVE RESISTANCE REGION
An operating region of an active solid-state electronic device in which an increase in applied voltage results in a decrease in output current.
NEGATIVE TEMPERATURE COEFFICIENT
The amount of reduction in a device parameter, such as capacitance or resistance, for each degree of device operating temperature.
NMOS N-channel metal oxide semiconductor devices which use electrons as majority carriers.
NONDOPANT
An impurity added from an external source which does not modify the electrical properties of a semiconductor.
NPN TRANSISTOR
A bipolar transistor with n-type emitter and collector regions separated by a p-type base.
N-CHANNEL FET
A field effect transistor that has an n-type conduction channel.
N-TYPE SEMICONDUCTOR
An extrinsic semiconductor having n-type dopant atoms (e.g., atoms with one or more valence electron than the host atoms). Electron density exceeds hole density.
ORDERED
Crystalline arrangement in which different constituent atoms of a compound semiconductor occupy specific lattice sites resulting in long range regularity of the resultant structure.
OUTDIFFUSION The solid-state diffusion of impurities from the underlying substrate into a deposited layer during the growth thereof.
PACKAGE
A container, case, or enclosure utilized in the context of
semiconductor art for protecting a solid-state electronic device from the environment and which is considered a part of a manufacture product (i.e., as opposed to a package utilized for passage of a product through the channels of trade in a safe, convenient, and attractive condition).
PAD
A. The portion of a conductive pattern on a solid-state electronic device for making external connection thereto. B. The portion of a conductive pattern on a chip or a printed circuit board designed for mounting or attaching a substrate or solid-state active electronic device. See also bonding pad, die bond, etc.
PARASITIC DEVICES/CHANNELS
A. Junctions forming unintended interconnection of intended active solid-state devices. B. Devices which were not designed to carry current flow and which result from unintended interconnection of intended active solid-state devices.
PASSIVE DEVICE
A solid-state electronic device or component in which charge carriers do not change their energy levels and that does not provide rectification, amplification, or switching, but which does react to voltage and current. Examples are pure resistors, capacitors, and inductors.
P-CHANNEL
A conduction path, made of p-type semiconductor material, located between source and drain of a field effect device. PHOTODIODE
A diode in which charge carriers are created by light which illuminates the diode junction. It is a photovoltaic as well as a photoconductive device.
PINCH-EFFECT RESISTOR
A monolithic integrated circuit resistor having a layer of one conductivity type, typically a P-layer formed at the same time as integrated circuit bipolar transistor base regions, which is thinned by an inset region of opposite conductivity type, typically an N-layer formed at the same time as integrated circuit bipolar transistor emitter regions.
PIN DIODE/DEVICE
A diode having an intrinsic semiconductor (i.e., one with no dopants) sandwiched between a p-type layer and an n-type layer. The depletion region (the intrinsic semiconductor layer) thickness can be tailored to optimize quantum
efficiency for use as a photo diode or frequency response for use as a microwave diode.
PIN-GRID ARRAY
A semiconductor chip package having leads in the form of pins arranged in columns and rows.
PLANAR TRANSISTOR
A bipolar transistor in which the emitter base and collector regions terminate at the same plane surface without indentations in or protrusions from the surface. Hence, the emitter and base regions form dish-shaped portions extending into the semiconductor from the common surface.
PN-JUNCTION The interface and region of transition between p-type and n-type semiconductors. See also barrier layer.
PN-JUNCTION DIODE
A semiconductor device having two terminals connected to opposite-type semiconductor materials with a junction therebetween and exhibiting a nonlinear voltage-current characteristic, usually used for switching or rectification.
PNP TRANSISTOR
A bipolar transistor with p-type emitter and collector regions separated by an n-type base.
POINT DEFECT
A crystal defect occurring at a point in a crystal. Examples include (a) a foreign atom incorporated into the crystal lattice at either a substitutional (regular lattice) site or interstitial (between regular lattice sites) site, (b) a missing atom in the lattice, or (c) a host atom located between regular lattice sites and adjacent to a vacancy (called a Frenkel defect). See CRYSTAL DEFECT for other examples of crystalline defects.
POLYSILICON
A polycrystalline form of silicon.
POTENTIAL BARRIER
The difference in electrical potential across a pn junction in a semiconductor. See also barrier layer.
POTTING An embedding process in which an electronic component is placed in a can, shell, or other container and buried in a
fluid dielectric which subsequently is hardened material. Even though the container is not removed from the finished part, this is considered a molding operation since the fluid is confined to a definite shape during hardening.
PRINTED CIRCUIT BOARD
A structure formed on one or more layers of electrically insulating material having electrical terminals and conductive material deposited thereon, in continuous paths, from terminal to terminal, to form circuits for electronic apparatus such as chips or substrates.
P-TYPE
An extrinsic semiconductor in which the hole density exceeds the conduction electron density.
PUNCHTHROUGH
Expansion of a depletion region* from one junction to another junction in an active solid-state device.
QUANTUM TRANSISTOR
Transistors whose operation is based on the properties of electrons confined in quantum wells - semiconductor films only a hundred or so angstroms thick sandwiched between high confining walls made of a second semiconductor material.
QUANTUM WELL
Semiconductor films only a hundred or so angstroms thick sandwiched between high confining walls made of a second material. RECOMBINATION
The process by which excess holes and electrons in a semiconductor crystal recombine and no longer function as charge carriers in the semiconductor. Basic recombination processes are band-to-band recombination which occurs when an electron in the conduction band recombines with a hole in the valence band, and trapping recombination which occurs when an electron or hole is captured by a deep energy level, such as produced by a deep level dopant, before recombining with an opposite conductivity-type carrier.
RESISTIVITY
A measure of the resistance of a material to electric current. Resistivity is a bulk material property measured in ohm-cm.
RESONANT TUNNELLING DEVICE
A device that works on the principle of resonant electron (or
hole) tunneling through a pair of matched potential barriers. This occurs when the energy of the electrons (or holes) matches that of a quantum energy level in the quantum well formed between the barriers.
SEMICONDUCTOR
A. A generic term for (1) a substance or material whose electronic conductivity at ordinary temperature is intermediate between that of a metal and an insulator and whose conductivity is capable of being modified by the addition of a dopant or (2) an electronic device the main functioning parts are made from semiconductor materials.
B. For the purposes of Class 438, a semiconductor material (1) must have resistivity between that of an insulator and a conductor and (2) be intended for use in a solid state device for at least one of the following purposes: (a) conducting or modifying an electrical current, (b) storing electrical energy for subsequent discharge, or (c) converting electromagnetic wave energy to electrical energy or electrical energy to electromagnetic energy. The resistivity is commonly changed by light, heat, or electric or magnetic fields incident on the material.
SEMICONDUCTOR JUNCTION
The region of transition, which usually exhibits asymmetric conductivity, between two joined semiconductors of different electrical properties or of joined semiconductor and conductor (e.g., metal, etc.) and which is also referred to in the art as a barrier layer. Types of junctions include heterojunctions, Schottky barrier junctions, and PN junctions. SILICON ON INSULATOR (SOI)
A semiconductor structure using an insulating substrate, instead of silicon as a substrate material, with an overlying active layer of single crystal silicon containing active solid state devices. The substrate may typically be of the form of an insulating layer which is itself formed on a single crystal substrate.
SILICON ON SAPPHIRE (SOS) CMOS
A complementary metal oxide semiconductor device (e.g., a transistor) wherein single crystal silicon is grown on a passive insulating base of sapphire (single crystal alpha phase aluminum oxide) with complementary MOS transistors formed in the silicon in one or more island portions.
SINGLE CRYSTAL
A body of material having atoms regularly located at periodic lattice sites throughout.
SINKER
A buried electrically conductive, low resistance path in an integrated circuit which connects an electrical contact to a conductive region buried in the integrated circuit. It may be made up of a heavily doped impurity region.
SOLID-STATE DEVICE
An electronic device or component that uses current flow through solid (as opposed to liquid), gas, or vacuum materials. Solid-state devices may be active or passive.
SOURCE In a field effect transistor, the active region/electrode to which the source of charge carriers is connected.
SPACE CHARGE REGION
The region around a pn junction in which holes and electrons recombine to leave no mobile charge carriers and a net charge density due to the residual dopant ions.
SPIKING
Phenomena associated with electromigration wherein a fingerlike protrusion of a metallization layer is allowed to grow through a dielectric layer and eventually contact a further layer.
SUBSTRATE
A. A base upon which a coating is formed. See the class definition for the requirements for coating, per se, or etching, per se, when a base of semiconductor or containing a semiconductive region is the substrate. B. The supporting material on or in which the components of an integrated circuit are fabricated or attached.
SUPERLATTICE
A periodic sequence of variations in carrier potential energy in a semiconductor, of such magnitude and spacing that the current carrier wave function is spread out over many periods, so that carrier energy and other properties are determined in part by the periodic variations. The variation may be in chemical composition of the material, as in a sequence of heterojunctions, or in impurity concentration, forming a doping superlattice, or both.
SURFACE MOUNT DEVICES
Active or passive solid-state devices which are structured and configured to be mounted directly to a printed circuit board surface. This type of mounting is distinguished from "through-hole" mounting which involves the electrical and
physical connection of devices to a printed circuit board using drilled and plated holes through the conductive pattern of the board. SURFACE RESISTIVITY
The resistance of a material between two opposite sides of a unit square of its surface. Also called Sheet Resistance. Measured in ohms, often written as "ohms per square" in this case.
THERMISTOR
A thermoelectric device whose electrical resistance varies with temperature. Its temperature coefficient of resistance is high, nonlinear, and usually negative.
THIN-FILM
A material on a substrate with a thickness not greater than 10 microns and uniformity within 20% of it's average value (Grant and Hackh's Chemical Dictionary, 5th Edition, edited by Roger & Claire Grant, McGraw-Hill, Inc., 1987, page 235).
THICK-FILM DEVICES
Printed thin-film circuits. Silk screen printing techniques are used to make the desired circuit patterns on a ceramic substrate. Active devices may be added thereto as separate devices (see HYBRID CIRCUIT).
THIN-FILM DEVICES
Solid-state electronic devices which are constructed by depositing films of conducting material on the surface of electrically insulating bases.
THYRISTOR
A four layer p-n-p-n bistable switching device that changes from an off or blocking state to an on or conducting state which uses both electron and hole-type carrier transport. TRANSFERRED ELECTRON DEVICE
See GUNN EFFECT. In such devices, advantage is taken of the negative differential mobility of electrons or holes in certain semiconducting compounds, particularly GaAs or InP.
TRANSISTOR
An active solid-state semiconductor device having three or more electrodes in which the current flowing between two specified electrodes is modulated by the voltage or current applied to one or more specified electrodes, and is capable of performing switching or amplification. May be of unipolar type (i.e., field effect transistor) or bipolar type.
TRAPATT DEVICE
An acronym for trapped plasma avalanche triggered transit diodes, which are biased into avalanche condition. As the diode breaks down, a highly conducting electron-hole plasma quickly fills the entire n-type region, and the voltage across the diode drops to a low value. The plasma is then extracted from the diode by the low residual electric field, thus causing a large current flow even though the voltage is low. Once extraction of the plasma is completed, the current drops and the voltage rises.
TRENCH ISOLATION
Electrical isolation of electronic components in a monolithic integrated circuit by the use of grooves or other indentations in the surface of the substrate, which may or may not be filled with electrically insulative (i.e., dielectric) material.
TUNNEL DIODE
A semiconductor diode in which the electrons penetrate a quantum barrier that is impenetrable in terms of classical physics, but which is penetrable in terms of quantum physics due to the quantum mechanical uncertainty in position of current carriers.
TWO-DIMENSIONAL ELECTRON GAS A description of the motion of electrons which are confined in only one direction, such as electrons in the conducting channel of a MOSFET. In an electron gas, the electrons move around without apparent restriction. The behavior of electrons in conducting metals (e.g., copper) is an example of a three-dimensional electron gas. In a two dimensional electron gas, motion is restricted to a single plane (two dimensions). See also MODFET.
UNIPOLAR
An active solid-state electronic device in which only one type of charge carrier (i.e., positive holes or negative electrons) is used to support current flow.
VARACTOR
A semiconductor diode comprising a two terminal active device using the voltage variable capacitance of a pn junction or a Schottky junction that changes capacitance with a change in applied voltage.
VARISTOR
A varistor is a two-electrode active or passive semiconductor device with a voltage dependent nonlinear resistance which
falls significantly as the voltage is increased. In an active device, the nonlinear property is due to the presence of one or more potential barriers. In a passive-type varistor, it is due to electrical heating of the material due to current flow therethrough. Varistors are to be contrasted with passive variable resistors such as rheostats or potentiometers.
VIA
A metallized or plated-through hole in an insulating layer, a semiconductor containing substrate or chip, or a printed circuit board which forms a conduction path itself without having a wire or lead inserted therethrough.
WAFER
A thin slice of semiconductor material with parallel faces used as the substrate for active solid-state devices in discrete or monolithic integrated circuit form. WIRING CHANNEL
An area on an integrated circuit, such as a gate array, which is left free of active devices and in which interconnection metallization patterns are formed.
WORK FUNCTION
The minimum energy required to remove an electron from the Fermi level of a material and liberate it to free space outside the solid.
ZENER DIODE
A single pn junction, two terminal semiconductor diode reversed biased into breakdown caused by the Zener effect (i.e., by field emission of charge carriers in the device's depletion layer). NOTE: True Zener breakdown occurs in silicon at values below 6 volts. It is to be distinguished from the avalanche breakdown mechanism that occurs in reverse biased diodes at higher (about 6 volts) voltages.