Method of producing semi-conductive devices, more particularly transistors

Claim 1

IN THE METHOD OF MANUFACTURING A SEMICONDUCTOR DEVICE IN WHICH A MASS OF ELECTRODE-FORMING MATERIAL CONTAINING A FIRST ACTIVE IMPURITY OF ONE CONDUCTIVITY-TYPE HAVING A RELATIVELY HIGH SEGREGATION CONSISTANT AND A RELATIVELY LOW DIFFUSION VELOCITY IS FUSED AND METHOD TO A SEMICONDUCTIVE BODY TO PENETRATE THEREIN IN THE PRESENCE OF A SECOND IMPURITY OF THE OPPOSITE CONDUCTIVITY-TYPE HAVING A RELATIVELY LOW SEGREGATION CONSISTANT AND A RELATIVELY HIGH DIFFUSION VELOCITY AND THE SECOND IMPURITY IS CAUSED TO DIFFUSE INTO THE BODY VIA THE SOLID-LIQUID INTERFACE TO FORM A DIFFUSED REGION WHOSE CONDUCTIVITY IS GENERALLY DOMINATED BY THE SECOND IMPURITY AND THE MELT IS THEREAFTER COOLED TO RECRYSTALLIZE A SEMICONDUCTIVE REGION ADJACENT THE DIFFUSED REGION WHOSE CONDUCTIVITY IS DOMINATED BY THE FIRST IMPURITY, THE IMPROVEMENT COMPRISING IN COMBINATION THEREIN THE STEP OF, AFTER THE DIFFUSING STEP FORMING THE DIFFUSED REGION BUT BEFORE THE COOLING TO RECRYSTALLIZE STEP, SUBJECTING THE BODY AND MATERIAL TO A FURTHER THERMAL TREATMENT AT A TEMPERATURE JUST ABOVE THAT OF THE DIFFUSING STEP CAUSING THE MOLTEN ELECTRODE-FORMING MATERIAL TO PENETRATE DEEPER INTO THE BODY AND DISSOLVE THE ADJACENT PORTION OF THE DIFFUSED REGION TO AT LEAST PARTLY ELIMINATE THE PORTIONS THEREOF CONTAINING SUBSTANTIAL QUANTITIES OF THE FIRST IMPURITY, SAID FURTHER THERMAL TREATMENT HAVING SO SHORT A DURIATION THAT SUBSTANTIALLY NO FURTHER DIFFUSION OF THE SAID IMPURITIES OCCURS.