Bipolar transistor structure having ion implanted region and method

Claim 1

IN A METHOD FOR FABRICATING A SEMICONDUCTOR DEVICE WITHIN A SEMICONDUCTOR BODY OF ONE CONDUCTIVITY TYPE HAVING A PLANAR SURFACE AND USING ION IMPLANTATION, FORMING AN INSULATING LAYER ON SURFACE, FORMING SIMULTANEOUSLY A PLURALITY OF SPACED OPENINGS IN SAID INSULATING LAYER AND EXPOSING SAID SURFACE IN SAID OPENINGS WITH AT LEAST ONE OPENINGS FOR THE BASE AND AT LEAST ONE OPENING FOR THE EMITTER, COVERING THE EMITTER, OPENING AND THE PORTIONS OF INSULATING MATERIAL SURROUNDING THE BASE PUT WITH PORTIONS OF THE INSULATING MATERIAL OVERLYING THE BASE BEING EXPOSED WITH A PROTECTIVE MATERIAL OF SUFFICIENT THICKNESS TO PROVENT ANY SUBSTANTIAL PENETRATION BY THE ION BEAM USED FOR ION IMPLATATION, UNCOVERING THE BASE OPENING, IMPLANTING IONS OF AN IMPURITY OF OPPOSITE CONDUCTIVITY TYPE THROUGH THE UNCOVERED OPENING TO FORM A BASE REGION OF OPPOSITE CONDUCTITITY TYPE EXTENDING TO SAID SURFACE AND HAVING PORTIONS EXTENDING TO DIFFERENT DEPTHS FROM SAID SURFACE, COVERING THE BASE OPENING WITH A PROTECTIVE MATERIAL TO PREVENT ANY SUBSTANTIAL PENETRATION BY THE ION BEAM, REMOVING THE PROTECTIVE MATERIAL FROM THE EMITTER OPENING, IMPLANTING IONS OF AN IMPURITY OF SAID ONE CONDUCTIVITY TYPE INTO SAID EMITTER OPENING FROM WHICH THE PROTECTIVE MATERIAL HAS BEEN REMOVED TO FORM AN EMITTER REGION OF SAID ONE CONDUCTIVITY TYPE EXTENDING TO THE SURFACE WITHIN THE BASE REGION AND WITH THE OUTER PERIMETER OF THE EMITTER REGION IN CLOSE PROXIMITY TO A PORTION OF THE BASE REGION OR LESSER DEPTH AND FORMING CONTACT ELEMENTS ON SAID LAYER OF INSULATING MATERIAL AND EXTENDING THROUGH SAID LAYER OF INSULATING MATERIAL TO MAKE CONTACT WITH SAID BASE AND EMITTER REGIONS.