Patent ID: 7618879
Filing Date: 2009-11-17
Classification: H01L,Y10S

Abstract:
1. A process for heat-treating a single crystal silicon segment to influence a concentration profile of minority carrier recombination centers in the segment, the silicon segment having a front surface, a back surface, a central plane between the front and back surfaces, a surface layer which comprises the region of the segment between the front surface and a distance, D, measured from the front surface and toward the central plane, and a bulk layer which comprises the region of the segment between the central plane and surface layer, the process comprising: heat-treating the segment in an atmosphere to form crystal lattice vacancies in the surface and bulk layers; controlling a cooling rate of the heat-treated segment to produce a segment having a vacancy concentration profile in which a peak density is at or near the central plane with the concentration generally decreasing in the direction of the front surface of the segment; and, thermally diffusing platinum atoms into a silicon matrix of the cooled segment such that a platinum concentration profile is substantially dependent upon the vacancy concentration profile.