Semiconductor device and method of making

Claim 1

THE METHOD OF MAKING A PN JUNCTION DIODE HAVING A SUBSTANTIALLY MICROPLASMA-FREE JUNCTION COMPRISING THE STEPS OF DISTILLING THE DIFFUSANT METAL IN A CONTAINER AND QUENCHING TO CONDENSE THE METAL INTO A PLURALITY OF DROPLETS ON THE CONTAINER WALLS, PLACING A DROPLET OF THE DIFFUSANT METAL AND A WAFER OF SEMICONDUCTOR MATERIAL IN A SECOND CONTAINER AT SPACED REGIONS THEREOF AND SEALING THE CONTAINER, DIFFUSING THE DROPLT INTO THE WAFER BY HEATING IN A FURNACE AT APPROXIMATELY 800*C. TO 1000*C. FOR APPROXIMATELY THIRTY MINUTES WITH THE WAFER LOCATED ABOVE THE DROPLET, PLACING THE SEALED CONTAINER IN A TEMPERATURE GRADIENT WITH THE WAFER AT AT LEAST 800*C. AND THE REST OF THE CONTAINER BELOW 500*C. FOR AT LEAST ONE MINUTE, QUENCHING THE WAFER IN AIR WITHOUT UNSEALING THE CONTAINER, REMOVING THE WAFER FROM THE SEALED CONTAINER AND REMOVING THE JUNCTION ON ONE FACE OF THE WAFER, EVAPORATING PURE TIN ON SAID ONE FACE OF SAID WAFER TO A THICKNESS OF BETWEEN 3000-6000 ANGSTROMS, IN A VACUUM CHAMBER, COOLING THE WAFER TO ROOM TEMPERATURE BEFORE REMOVING FROM THE VACUUM, ELECTROPLATING THE ENTIRE WAFER WITH NICKEL, WASHING IN DISTILLED WATER, SINTERING, AND ELECTROPLATING AGAIN FOR APPROXIMATELY ONE MINUTE, THEN WASHING IN DISTILLED WATER, GOLD PLATING THE NICKEL SURFACE OVERLYING THE TIN PLATING AND THE OPPOSITE NICKEL PLATED SURFACE OF THE WAFER, THE N-TYPE SIDE BEING PLATED FOR APPROXIMATELY 15 SECONDS AND THE P-TYPE SIDE FOR FROM, TWO TO THREE SECONDS, DICING THE WAFER TO SIZE, MOUNTING A SIZED DIE ON A HEADER WITH THE N-TYPE SIDE ADJACENT THE HEAD, ETCHING THE ASSEMBLY TO ACHIEVE A CAPACITANCE OF FROM 1.5 TO 2,5 MMF., THEN WASHING AND MOUNTING A CONTACT TO THE P-TYPE SIDE OOF THE DIE.