Semiconductor device and method of manufacture thereof

A semiconductor device pellet comprising:

• a pellet of semiconductor material defining two major surfaces, said pellet comprising three stacked regions, the interior region being of one conductivity type and the outer regions being of the opposite conductivity type with the interfaces of said regions defining respective P/N junctions;
• a peripheral isolation region extending from one major face to the other, said isolation region being of the opposite conductivity type and being formed by thermomigration of an impurity which imparts said opposite conductity type;
• said isolation region having said impurity uniformly distributed therein in a concentration substantially equal to the solid solubility concentration of said impurity in said semiconductor material;
• said isolation region having an interior sidewall intersecting perpendicularly the interfaces between said interior region and both of said outer regions, and said isolation region thereby forming with said outer regions a complete enclosure of opposite conductivity type surrounding said interior region;
• a peripheral groove formed in one of said major surfaces and extending completely through one of said outer regions and bottoming in said interior region:
• the portion of said one major surface which is surrounded by said groove being thereby electrically isolated from the remainder of said one major surface;
• and
• passivation material in said groove covering the edges of the intersection of said interior region with said groove.