Transistor manufacturing process

Claim 1

IN A PROCESS OF TRANSISTOR MANUFACTURE WHEREIN SUCCESSIVE RECTIFYING JUNCTIONS ARE FORMED BY DIFFUSION OF DOPANTS INTO ONE SIDE OF A WAFER OF SEMICONDUCTING MATERIAL AND THERE IS SUBSEQUENTLY REMOVED A PORTION OF THE OTHER SIDE OF THE WAFER OT ESTABLISH A SMALL COLLECTOR THICKNESS, THE IMPROVEMENT COMPRISING COATING THE OTHER SIDE OF THE WAFER WITH A METAL CHOSEN FROM THE GROUPING CONSISTING OF IRON, NICKLE, COPPER, GOLD AND SILVER AT A STAGE OF MANUFACTURE PRIOR TOREMOVAL OF SAID PORTION OF THE WAFER AND FOLLOWING FORMATION OF A LEAST ONE JUNCTION OF THE TRANSISTOR, HEATING THE COATED WAFER TO AT LEAST THE EUTECTIC TEMPERATURE OF THE COATING MATERIAL AND SAID SEMICONDUCTING MATERIAL FOR A PERIOD OF A FEW MINUTES FOR DIFFUSING SAID METAL THROUGHOUT THE TRANSISTOR IN A QUANTITY LESS THAN THAT REQUIRED TO CHANGE THE CONDUCTIVITY TYPE OF ANY PORTION OF THE TRANSISTOR, AND REMOVING SAID COATING BY SAID SUBSEQUENT MANUFACTURING STEP OF REDUCING THE WAFER THICKNESS, WHEREBY THE RESULTANT TRANSISTOR HAS SHARPLY VARYING CURRENT-VOLTAGE CHARACTERISTICS.