Variable capacity diode fabrication method with selective diffusion of junction region impurities

Abstract

Abstract A VARIABLE CAPACITY DIODE WTH A HYPERABRUPT P-N JUNCTION IS FABRICATED BY CUTTING A HOLE THOROUGH AN OXIDE COATING ATOP A P-TYPE SEMICONDUCTOR LAYER EPITAXIALLY GROWN ON A MORE HEAVILY DOPED P-TYPE SEMICONDUCTOR SUBSTRATE, INTO THE EPITAXIALLY GROWN LAYER. A STRONGLY NTYPE REGION CONTAINING BOTH DONOR IMPURITIES AND FASTER DIFFUSING ACCEPTOR IMPURITIES IS THEN GROWN EPITAXIALLY IN THE HOLE FROM THE SEMICONDUCTOR AT THE BOTTOM OF THE HOLE. THE SUBSTRATE IS THEN HEATED TO CAUSE THE MORE RAPIDLY DIFFUSING ACCEPTOR IMPURITIES TO DIFFUSE INTO THE EPITAXIALLY GROWN LAYER AHEAD OF THE MORE SLOWLY DIFFUSING DONOR IMPURITIES AND FORM A NARROW REGION OF P+ CONDUCTIVITY, RESULTING IN THE DESIRED N+P+PP+ STRUCTURE.

Inventors

• 👤 William E Engeler

Bibliographic Details