Method of making field-effect transistors

Claim 1

METHOD OF MAKING A FIELD-EFECT SEMICONDUCTOR DEVICE WHICH COMPRISES: FORMING A BODY OF SEMICONDUCTOR MATERIAL HAVING BOTH P-TYPE AND N-TYPE IMPURITIES, EACH TYPE HAVING DIFFERENT NET OUTDIFFUSION RATES WITH THE CONCENTRATION OF IMPURITIES OF THE TYPE HAVING THE GREATER NET OUTDIFFUSION RATE BEING SUBSTANTIALLY GREATER THAN THE CONCENTRATION OF THE OTHER TYPE; OUTDIFFUSING A SUFFICIENT PORTION OF THE IMPURITIES TO FORM A REGION OF SEMICONDUCTOR MATERIAL AT THE SURFACE OF SAID BODY HAVING A NET CONCENTRATION OF IMPURITIES OF THE TYPE HAVING THE SLOWER OUTDIFFUSION RATE, WHILE LEAVING THE REMAINDER OF SAID BODY WITH A NET CONCENTRATION OF THE FASTER TYPE; MASKING A CENTRAL PORTION OF THE SURFACE OF SAID SURFACE REGION AND DIFFUSING IMPURITIES OF THE FASTER OUTDIFFUSING CONDUCTIVITY TYPE AROUND SAID MASK TO A DEPTH SUFFICIENT TO MAKE CONTACT WITH SAID REMAINDER OF SAID BODY BENEATH SAID SURFACE REGION, THEREBY ISOLATING A CHANNEL WITHIN SAID SURFACE REGION OF THE CONDUCTIVITY TYPE OF THE SLOWER OUTDIFFUSING IMPURITIES; DIFFUSING ADDITIONAL IMPURITIES OF THE SLOWER OUTDIFFFUSING CONDUCTIVITY TYPE INTO AT LEAST TWO SPACED-APART AREAS OF SAID CHANNEL; DIFFUSING INTO SAID SURFACE REGION A SUFFICIENT AMOUNT OF IMPURITIES OF THE FASTER OUTDIFFUSING CONDUCTIVITY TYPE TO BURY THE SURFACE OF SAID CHANNEL EXCEPT AT SAID SPACED-APART AREAS; AND PLACING THREE ELECTRODES IN OHMIC CONTACT WITH SAID BODY TWO OF WHICH ARE IN CONTACT WITH SAID SPACEDAPART AREAS OF SAID CHANNEL AND OTHER IS IN CONTACT WITH AN AREA OF THE BODY OF OPPOSITE CONDUCTIVITY TYPE FROM SAID CHANNEL.