(under subclass 487) Subject matter wherein the means for increasing breakdown voltage in the device includes a reverse biased pn junction guard region, that is, a region located in the material forming one side of an active pn or other rectifying semiconductor junction, which region forms a pn junction with the material of the one side of the active junction, the guard region being adapted to be reverse biased with respect to the material forming one side of the active junction, and being spaced from the active junction, but sufficiently close thereto that the reverse bias depletion region from the active junction can reach the depletion region from the reverse biased guard junction, whereby the depletion region of the guard junction modifies the shape of the depletion region from the active junction thus lowering the electric field intensity at a given applied reverse voltage across the active junction.
