Method of producing transistors

Claim 1

IN THE METHOD OF MAKING A DIFFUSED TRANSISTOR ON A BODY OF SEMICONDUCTIVE MATERIAL OF ONE CONDUCTIVITY TYPE, WHEREIN FIRST AND SECOND OPPOSITE-CONDUCTIVITY-TYPEFORMING IMPURITIES ARE DIFFUSED INTO THE BODY FROM ITS SURFACE, SAID FIRST IMPURITY HAVING A GREATER SOLUBILITY IN THE SEMICONDUCTIVE MATERIAL AND A SMALLER DIFFUSION COEFFICIENT THAN THAT OF THE SECOND IMPURITY, WHEREBY THERE IS FORMED WITHIN THE BODY AN INNER ZONE OF THE OPPOSITE CONDUCTIVITY TYPE DETERMINED BY THE SECOND IMPURITY AND FORMING A JUNCTION WITH THE BODY INTERIOR, AND AN OUTER SURFACE ZONE OF THE SAID ONE CONDUCTIVITY TYPE DETERMINED BY THE FIRST IMPURITY AND FORMING A JUNCTION WITH THE INNER ZONE, THE IMPROVEMENT COMPRISING, BEFORE DIFFUSING IN THE FIRST AND SECOND IMPURITIES, FIRST DIFFUSING INTO THE BODY A THIRD IMPURITY HAVING A GREATER SOLUBILITY THAN THAT OF THE FIRST AND SECOND IMPURITIES AND A DIFFUSION COEFFICIENT AT LEAST EQUAL TO THAT OF THE FIRST IMPURITY AND OF THE OPPOSITE CONDUCTIVITY-FORMING-TYPE AS THE LATTER TO FORM A SURFACE ZONE WITHIN THE BODY OF THE SAID OPPOSITE CONDUCTIVITY TYPE AND OF HIGHER CONDUCTIVITY AND THEREAFTER REMOVING PART OF THE SAID HIGH CONDUCTIVITY SURFACE ZONE THEREBY EXPOSING THE BODY INTERIOR AFTER WHICH THE FIRST AND SECOND IMPURITIES ARE DIFFUSED INTO THE BODY, AND CONTACTING THE HIGH CONDUCTIVITY SURFACE ZONE REMAINING TO EFFECT AN OHMIC CONNECTION TO THE SAID INNER ZONE.