Mesa epitaxial diode with oxide passivated junction and plated heat sink

Claim 1

A silicon mesa epitaxial diode, comprising: a. a first layer of lightly doped silicon of a first conductivity type, said first layer comprising a base segment of a mesa structure; b. a second layer of heavily doped silicon of the first conductivity type in contact with said first layer and extending the mesa from said first layer; c. a passivation layer of highly pure SiO 2 thermally grown at a temperature in excess of 1000° C. on the mesa walls only of said first and second layers and continuing outwardly from said base segment, said passivation layer having a thickness of between 1 and 1.5 microns; d. means for providing a shallow abrupt pn junction in said first layer, said means including a layer of dopant of a second conductivity type diffused in a surface region of said first layer and extending across said surface region into contact with said layer of highly pure thermally grown SiO 2 , said shallow abrupt pn junction characterized as being formed subsequent to the formation of said passivation layer so that diffusion of said dopant does not occur as a result of the thermal growth of said passivation layer; e. a thick layer of thermally and electrically conductive metal plated directly on said layer of dopant and said passivation layer continuing outwardly from said base segment; and f. a third layer of electrically conductive material on said second layer, said third layer in electrical contact with said second layer and extending the mesa from said second layer.