Patent ID: 6919241

Claim:
The process for the manufacture of a substrate for a superjunction device, said process comprising the steps of: forming only a first epitaxial semiconductor layer of a given thickness and of a given impurity concentration of a first conductivity type atop a support body; forming a plurality of spaced implants of a second conductivity type on the surface of said first epitaxial layer; forming only a second epitaxial layer of a given thickness and of a given concentration and of said first conductivity type atop said first layer; and thereafter heating said substrate and said implants to cause said implants to diffuse downwardly into said first layer and upwardly into said second layer, thereby forming spaced pedestals of said second conductivity type within said first and second layers; the total charge of each of said pedestals being approximately equal to the total charge in the volume of said first and second layers which surrounds said pedestals, wherein said first epitaxial semiconductor layer and said second epitaxial semiconductor layer together form a single epitaxial layer, and wherein said pedestals are formed near a central region of said single epitaxial layer spaced from said support body.