Patent ID: 6808781
Filing Date: 2004-10-26
Classification: H01L,Y10T

Abstract:
A single crystal silicon wafer having two major, generally parallel surfaces, one of which is the front surface of the wafer and the other of which is the back surface of the wafer, a central plane between the front and back surfaces, and a circumferential edge joining the front and back surfaces, the wafer comprising:a dopant selected from a group consisting of nitrogen and carbon, the concentration of the dopant being sufficient to promote the formation of stabilized oxygen precipitate nucleation centers as the wafer is cooled from a first temperature, T1, to a second temperature, T2, at a rate, R, the stabilized oxygen precipitation nucleation centers being incapable of being dissolved at a temperature less than about 1150Â° C. but capable of being dissolved at a temperature between about 1150Â° C. and about 1300Â° C., wherein T1 is between about 1150Â° C. and about 1300Â° C., T2 is a temperature at which crystal lattice vacancies are relatively immobile in silicon, and R is at least about 5Â° C. per second; a surface layer which comprises the region of the wafer between the front surface and a distance, D, measured from the front surface and toward the central plane, wherein the surface layer is free of stabilized oxygen precipitate nucleation centers; and a bulk layer which comprises a second region of the wafer between the central plane and the surface layer, wherein the bulk layer comprises stabilized oxygen precipitate nucleation centers.