Method for making a semiconductor device

Claim 1

IN A METHOD OF MAKING A SEMICONDUCTOR DEVICE WHEREIN A SEMICONDUCTOR SLAB OF ONE TYPE CONDUCTIVITY HAS A CONTINUOUS ZONE OF THE OPPOSITE CONDUCTIVITY DIFFUSED THEREINTO AND ABOUT THE ENTIRE SURFACE THEREOF TO FORM AN AT LEAST SUBSTANTIALLY UNIFORM THICKNESS USING DOPING MATERIAL OF THE OPPOSITE CONDUCTIVITY TYPE, THE IMPROVEMENT COMPRISING THE STEPS OF: (A) ALLOYING AN OHMIC CONTACT INTO ONE SURFACE OF THE SEMICONDUCTOR SLAB WHICH HAS A PORTION OF ONE TYPE CONDUCTIVITY EXTENDING AT LEAST SUBSTANTIALLY PARALLEL TO THE SLAB SURFACE AND WHICH PORTION IS SURROUNDED ON ALL SIDES BY A ZONE OF THE OPPOSITE CONDUCTIVITY TYPE FORMED BY DIFFUSION, SAID CONTACT EXTENDING UP TO THE SLAB EDGE; (B) CONNECTING A RECTIFYING CONTACT AND AN OHMIC CONTACT ON THE OTHER SLAB SURFACE IN A POSITION SPACED A CERTAIN DISTANCE FROM THE SLAB EDGE; AND THEN (C) GRINDING A CHAMFER AT THE SLAB EDGE STARTING FROM SAID OTHER SLAB SURFACE, THE CHAMFERING BEING PERFORMED ALONG THE ENTIRE PERIPHERY SO THAT THE PNJUNCTION BETWEEN THE DIFFUSION ZONE AND THE PORTION ENCOMPASSED BY THE DIFFUSION ZONE IS SEPARATED INTO TWO PN-JUNCTIONS WHICH ARE NO LONGER CONNECTED WITH EACH OTHER AND WHOSE LINES OF INTERSECTION WITH THE CHAMFERED SURFACE HAVE A MINIMUM SPACING FROM EACH OTHER ALONG THIS SURFACE WHICH IS LARGER THAN THE SHORTEST DISTANCE BETWEEN THE TWO PN-JUNCTIONS WHICH ARE FORMED.