Semiconductor device including differing energy band gap materials

Claim 1

A SEMICONDUCTOR DEVICE COMPRISING A SUBSTANTIALLY MONOCRYSTALLINE SEMICONDUCTOR WAFER, SAID WAFER INCLUDING THEREIN A FIRST PN JUNCTION DEFINED BY THE BOUNDARY BETWEEN A FIRST REGION OF N-TYPE CONDUCTIVITY MATERIAL AND A REGION OF BORON-DOPED P-TYPE CONDUCTIVITY MATERIAL, SAID PN JUNCTION HAVING A SUBSTANTIALLY PLANAR CONFIGURATION EXCEPT FOR A PORTION THEREOF OF PHOSPHORUS DIFFUSED N-TYPE CONDUCTIVIT MATERIAL WHICH PROJECTS INTO SAID REGION OF P-TYPE CONDUCTIVITY MATERIAL, SAID PROJECTING PORTION HAVING A PLANAR BOUNDARY SUBSTANTIALLY PARALLEL TO THE REST OF SAID FIRST PN JUNCTION, A SECOND PN JUNCTION DEFINED BY THE BOUNDARY OF SAID P-TYPE CONDUCTIVITY REGION AND A SECOND N-TYPE CONDUTIVITY REGION, SAID SECOND PN JUNCTION HAVING A MAJOR PLANAR SURFACE SUBSTANTIALLY PARALLEL TO SAID FIRST PN JUNCTION, A HETEROJUNCTION DEFINED BY THE BOUNDARY BETWEEN TWO DIFFERENT SEMICONDUCTOR MATERIALS HAVING DIFFERING ENERGY GAP, SAID HETEROJUNCTION HAVING A SUBSTANTIALLY PLANAR CONFIGURATION PARALLEL TO SAID PN JUNCTION AND INTERSECTING AND PASSING THROUGH SAID PROJECTING PORTION OF SAID FIRST PN JUNCTION SO THAT PARTS OF SAID PROJECTING PORTION ARE ON BOTH SIDES OF SAID HETEROJUNCTION.