Semiconductor electrical translating device

Claim 2

A semiconductor device comprising a body of semiconductor material having a flat major surface, a first zone of said body of one conductivity type of graded resistivity having a surface area in said surface of the body, a second zone of said body of the opposite conductivity type of graded resistivity lying intermediate said first zone and the remainder of said body and having a surface area in said surface of the body encircling the surface area of the first zone, a third zone of the one conductivity type of high resistivity completely surrounding the portion of said body constituted by the first and second zones except at said surface and having a surface area in said surface of the body encircling the surface area of the second zone, said first, second, and third zones cooperating to provide the emitter, base, and collector regions, respectively, of a transistor, a coating of an adherent nonconductive material on said surface of the body, a first opening in said coating delineating a region of the surface area of the first zone free of nonconductive material, a first layer of conductive material on said region of the surface area of the first zone in ohmic contAct with the semiconductor material of the first zone, a first connecting lead to said first layer of conductive material providing an emitter connection, a second opening in said coating delineating a region of the surface area of the second zone free of nonconductive material, a second layer of conductive material on said region of the surface area of the second zone in ohmic contact with the semiconductor material of the second zone, a second connecting lead to said second layer of conductive material providing a base connection, a third layer of conductive material on the coating of nonconductive material, said third layer of conductive material overlying the edge of the junction between the second and third zones and the portions of the surface areas of the second and third zones adjacent the junction whereby all of the edge of the junction at the surface lies under nonconductive material of said coating and conductive material of said third layer, an ohmic connection to said third zone, and a third connecting lead to said ohmic connection providing a collector connection, all portions of said third layer of conductive material being separated physically and electrically from the body of semiconductor material by nonconductive material of said coating, and said third layer of conductive material being free of any electrical connection.