Method of manufacturing transistors particularly for switching purposes

Claim 1

A METHOD OF MANUFACTURING AN ALLOY-DIFFUSED TRANSISTOR ADAPTED FOR SWITCHING PURPOSES, COMPRISING DIFFUSING INTO A SEMICONDUCTOR BODY OF ONE-TYPE CONDUCTIVITY IMPURITIES FOR REDUCING THE LIFETIME OF CHARGE CARRIERS THEREIN AND SELECTED FROM THE GROUP CONSISTING OF GOLD, IRON, NICKEL AND COPPER, A PORTION OF SAID BODY BEING ADAPTED TO CONSTITUTE A COLLECTOR ZONE OF THE TRANSISTOR, FUSING TO A SURFACE OF SAID BODY OPPOSITE TO SAID COLLECTOR ZONE A CONTACT-FORMING MATERIAL COMPRISING LEAD AND INCLUDING AN ACTIVE IMPURITY CAPABLE OF FORMING SAID ONETYPE CONDUCTIVITY IN A CONCENTRATION PRODUCING IN THE BODY WHEN SOLIDIFIED A RECRYSTALLIZED EMITTER ZONE OF SAID ONETYPE CONDUCTIVITY AND ALSO INCLUDING AN ACTIVE IMPURITY HAVING A HIGH DIFFUSION COEFFICIENT AND CAPABLE OF REVERSING THE CONDUCTIVITY TYPE OF THE ADJACENT BODY PORTIONS WHEN THE LATTER IMPURITY IS DIFFUSED THEREIN, SAID CONTACTFORMING MATERIAL BEING SUBSTANTIALLY FREE OF THE SAID LIFETIME-REDUCING IMPURITIES, MAINTAINING THE CONTACT-FORMING MATERIAL ON THE BODY IN A FUSED STATE FOR A TIME SUFFICIENTLY LONG TO CAUSE THE DIFFUSING ACTIVE IMPURITY TO DIFFUSE FROM THE CONTACT-FORMING MATERIAL INTO THE BODY TO FORM A BASE REGION OF OPPOSITE-TYPE CONDUCTIVITY WITH A THICKNESS BETWEEN 0.1 AND 2 MICRONS AND SIMULTANEOUSLY TO CAUSE LIFETIME-REDUCING IMPURITIES AT LEAST IN THE SAID BASE REGION BETWEEN THE EMITTER ZONE AND COLLECTO ZONE TO OUTDIFFUSE FROM THE BODY INTO THE SAID CONTACT-FORMING MATERIAL, COOLING THE ASSEMBLY TO SOLIDIFY THE CONTACT-FORMING MATERIAL AND FORM THE EMITTER ZONE ADJACENT THE BASE REGION, AND PROVIDING ELECTRICAL CONTACTS TO THE EMITTER ZONE, THE BASE REGION, AND THE COLLECTOR ZONE.

Claim 2

A METHOD OF MANUFACTURING AN ALLOY-DIFFUSED TRANSISTOR ADAPTED FOR SWITCHING PURPOSES, COMPRISING DIFFUSING INTO A SEMICONDUCTOR BODY OF ONE-TYPE CONDUCTIVITY IMPURITIES FOR REDUCING THE LIFETIME OF CHARGE CARRIERS THEREIN AND SELECTED FROM THE GROUP CONSISTING OF GOLD, IRON, NICKEL AND COPPER, A PORTION OF SAID BODY BEING ADAPTED TO CONSTITUTE A COLLECTOR ZONE OF THE TRANSISTOR, FUSING TO A SURFACE OF SAID BODY OPPOSITE TO SAID COLLECTOR ZONE A CONTACT-FORMING MATERIAL COMPRISING LEAD AND INCLUDING AN ACTIVE IMPURITY CAPABLE OF FORMING SAID ONETYPE CONDUCTIVITY IN A CONCENTRATION PRODUCING IN THE BODY WHEN SOLIDIFIED A RECRYSTALLIZED EMITTER ZONE OF SAID ONETYPE CONDUCTIVITY AND ALSO INCLUDING AN ACTIVE IMPURITY HAVING A HIGH DIFFUSION COEFFICIENT AND CAPABLE OF REVERSING THE CONDUCTIVITY TYPE OF THE ADJACENT BODY PORTIONS WHEN THE LATTER IMPURITY IS DIFFUSED THEREIN, SAID CONTACTFORMING MATERIAL BEING SUBSTANTIALLY FREE OF THE SAID LIFETIME-REDUCING IMPURITIES, MAINTAINING THE CONTACT-FORMING MATERIAL ON THE BODY IN A FUSED STATE FOR A TIME SUFFICIENTLY LONG TO CAUSE THE DIFFUSING ACTIVE IMPURITY TO DIFFUSE FROM THE CONTACT-FORMING MATERIAL INTO THE BODY TO FORM A BASE REGION OF OPPOSITE-TYPE CONDUCTIVITY WITH A THICKNESS BETWEEN 0.1 AND 2 MICRONS AND SIMULTANEOUSLY TO CAUSE LIFETIME-REDUCING IMPURITIES AT LEAST IN THE SAID BASE REGION BETWEEN THE EMITTER ZONE AND COLLECTO ZONE TO OUTDIFFUSE FROM THE BODY INTO THE SAID CONTACT-FORMING MATERIAL, COOLING THE ASSEMBLY TO SOLIDIFY THE CONTACT-FORMING MATERIAL AND FORM THE EMITTER ZONE ADJACENT THE BASE REGION, AND PROVIDING ELECTRICAL CONTACTS TO THE EMITTER ZONE, THE BASE REGION, AND THE COLLECTOR ZONE.