ADJUSTMENT OF SEMICONDUCTOR WAFER FOR UNIFORM AND REPEATABLE HIGH-SPEED HEAT TREATMENT

PURPOSE: To form a uniform emissivity and surface conditions of a semiconductor wafer backside by forming a silicon nitride layer on the front surface and backside of a wafer, coating the backside of the wafer by a protective photoresist layer and peeling a nitride layer by using selective corrosion. CONSTITUTION: (1) A layer of silicon oxide 6 is deposited on an epitaxial wafer provided with a lightly doped region 2 on a heavily doped region 4. (2) A layer 10 of silicon nitride is deposited on the front surface and backside of the wafer. (3) The backside ion-implantation of a p-type material or the backside ion- implantation of an n-type material is executed. On a lightly doped p-substrate, the implantation includes boron driven by 200-400 keV for 1-2*10 atoms per cm . (4) The backside of the wafer is coated with a photoresist 12. (5) The layer 10 of the nitride on a front side is corroded and removed. (6) A layer 6 of oxide on the front side is peeled, and then the photoresist 12 is peeled. (7) The cleaning is executed before putting the wafer in a furnace generated by implantation annealing.