Patent ID: 6339016
Filing Date: 2002-01-15
Classification: C30B,H01L,Y10T

Abstract:
A method for the preparation of a semiconductor wafer comprising at least one surface having an epitaxial layer deposited thereon and a template of crystal lattice vacancies within the wafer which causes a non-uniform depth distribution of oxygen precipitates to form within the wafer when the wafer is heat-treated in a subsequent heat-treatment, said method includingplacing a semiconductor wafer in a chamber and applying an epitaxial coating to a surface thereof, said semiconductor wafer being in heat transfer relation with a susceptor during the coating application, and wherein, the semiconductor wafer rests on a plurality of pins during application of the coating whereby said semiconductor wafer has a substantial portion thereof spaced from the susceptor a distance of at least about 1 mm during application of the coating; heating said coated semiconductor wafer with a heat source to an elevated temperature of at least about 1175Â° C. in said chamber while maintaining said distance between the semiconductor wafer and the susceptor; and cooling said heated and coated semiconductor wafer in said chamber at a rate of at least about 10Â° C./sec. while maintaining said distance between the semiconductor wafer and said susceptor until said semiconductor wafer reaches a surface temperature of less than about 850Â° C.