Fabricating semiconductor devices

Claim 1

A METHOD OF FABRICATING SEMICONDUCTOR DEVICES WHICH COMPRISES THE STEPS OF OXIDIZING THE SURFACE OF A SEMICONDUCTOR BODY TO PRODUCE A SUBSTANTIALLY THICK OXIDE FILM OVER THE SURFACE, SAID BODY CONTAINING IMPURITIES WHICH WILL IMPART AN N OR A P-TYPE CONDUCTIVITY, EXPOSING A FIRST ISLAND OF UNOXIDIZED SURFACE OVER SAID BODY BY REMOVING A PORTION OF SAID FILM BY PHOTOENGRAVING, FORMING A FIRST REGION OF DIFFERENT CONDUCTIVITY TO THAT OF SAID SEMICONDUCTOR BODY BY DIFFUSING INTO SAID ISLAND A FIRST DIFFUSANT WHICH WILL PRODUCE SAID DIFFERENT CONDUCTIVITY AND TO WHICH SAID FILM IS IMPERVIOUS AND DIFFUSING SAID DIFFUSANT INTO SAID BODY IN A MINIMUM OXIDIZING ATMOSPHERE SO AS TO FORM A PN JUNCTION WITH SAID SEMICONDUCTOR BODY EXTENDING TO THE SURFACE BENEATH SAID THICK OXIDE LAYER AND TO REGROW AN OXIDE LAYER SUBSTANTIALLY THINNER THAN THE ORIGINAL FILM, ETCHING SAID SURFACE LIGHTLY TO REMOVE ONLY THE THIN OXIDE LAYER COVERING THE FIRST ISLAND AND THEREBY EXPOSE SAID ISLAND AND FORMING A SECOND REGION OF OPPOSITE CONDUCTIVITY TO THAT OF SAID FIRST REGION AND CONTAINED THEREWITHIN BY DEPOSITING ONTO SAID FIRST ISLAND A SECOND DIFFUSANT WHICH WILL PRODUCE SAID OPPOSITE CONDUCTIVITY AND TO WHICH SAID FILM IS IMPERVIOUS AND DIFFUSING SAID DIFFUSANT INTO SAID FIRST REGION IN A MINIMUM OXIDIZED ATMOSPHERE WHEREBY SAID ISLAND SURFACE IS REOXIDIZED TO A THICKNESS SUBSTANTIALLY THINNER THAN THE ORIGINAL FILM, EXPOSING A SECOND ISLAND OF UNOXIDIZED SURFACE BY CUTTING A HOLD IN SAID OXIDE FILM BY PHOTOENGRAVING, SAID HOLE BEING AT LEAST SUBSTANTIALLY EQUAL IN AREA TO THAT OF SAID ISLAND AND BEING LATERALLY DISPLACED FROM BUT OVERLAPPING SAID FIRST ISLAND, GROWING A LATERAL EXTENSION TO SAID FIRST REGION BY DEPOSITING ON SAID SECOND ISLAND A THIRD DIFFUSANT WHICH HAS IMPURITIES OF THE TYPE FORMING SAID FIRST REGION BUT TO WHICH SAID FILM IS IMPERVIOUS AND DIFFUSING SAID DIFFUSANT IN A MINIMUM OXIDIZING ATMOSPHERE INTO SAID BODY, SAID THIRD DIFFUSANT HAVING A CONCENTRATON OF IMPURITIES LESS THAN SAID SECOND REGION BUT GREATER THAN THAT OF SAID BODY SO THAT THE CONDUCTIVITY OF THE SECOND ISLAND AREA IS CHANGED TO THAT OF SAID FIRST REGION EXCEPT ISLAND AREA IS CHANGED TO THAT OF SAID FIRST REGION EXCEPT THAT PORTION COMPRISING SAID SECOND REGION, REMOVING THE THIN LAYER OF OXIDE FILM REGROWN OVER BOTH SAID ISLANDS BY LIGHTLY ETCHING SO AS TO REMOVE THE THIN LAYERS OF OXIDE BUT LEAVE THE ORIGINAL THICKER SURFACE OXIDE FILM, AND PLATING SEPARATE FIRST AND SECOND METAL STRIPS ONTO SAID BODY, SAID FIRST METAL STRIP COVERING AN AREA TO INCLUDE A PORTION OF SAID SECOND REGION EXPOSED BY THE PRECEDING STEP BUT NOT INCLUDING ANY PORTION OF SAID SECOND ISLAND, THEEBY FORMING AN OHMIC ELECTRICAL CONNECTION WITH SAID SECOND REGION BUT OVERLYING SAID BODY TO BE SUBSTANTIALLY IN LINE WITH BUT EXTENDING OUTWARDLY IN AN OPPOSITE DIRECTIN FROM SAID FIRST STRIP TO INCLUDE THE EXPOSED SURFACE OF SAID FIRST REGION TO WHICH AN OHMIC ELECTRICAL CONNECTION IS FORMED AND THEREBY OVERLYING OXIDE FILM AT ALL POINTS EXCEPT WHERE IN OHMIC CONTACT WITH SAID FIRST REGION.