Method for making a semiconductor device by diffusing impurities through spaced-apart holes in a non-conducting coating to form an overlapped diffused region by means oftransverse diffusion underneath the coating

Claim 1

IN THE MANUFACTURE OF A SEMICONDUCTOR DEVICE, THE METHOD STEPS OF: (A) FORMING A NON-CONDUCTING COATING ON A PLANE SURFACE OF A SEMINCONDUCTOR BODY OF ONE CONDUCTIVITY TYPE; (B) OPENING A FIRST HOLE THROUGH SAID COATING TO EXPOSE AN AREA OF SAID SURFACE; (C) DIFFUSING AN IMPURITY INTO SAID HOLE TO FORM A FIRST REGION OF OPPOSITE CONDUCTIVITY TYPE TO SAID ONE CONDUCTIVITY TYPE, WITH SAID REGION EXTENDING BY TRANSVERSE DIFFUSION UNDERNEATH SAID COATING TO SAID SURFACE; (D) REFORMING A NON-CONDUCTING COATING ON SAID SURFACE WITHIN SAID AREA; (E) OPENING A SECOND HOLE ADJACENT TO BUT SPACED FROM SAID FIRST HOLE THROUGH THE ORIGINAL COATING TO SAID SURFACE; (F) DIFFUSING AN IMPURITY INTO SAID SECOND HOLE TO FORM A SECOND REGION OF SAID OPPOSITE CONDUCTIVITY TYPE, SAID FIRST AND SECOND HOLES BEING SUFFICIENTLY CLOSE TOGETHER SO THAT SAID SECOND REGION MERGES WITH AN