Abstract: A silicon wafer containing oxygen precipitate nucleation centers (or oxygen precipitates) and having a first face, a second face, and a central plane equidistant between the first and second faces. The nucleation centers (or oxygen precipitates) have a non-uniform distribution between the first and second faces with a maximum density of the nucleation centers (or oxygen precipitates) being in a region which is between the first face and the central plane and nearer to the first face than the central plane. The density of the nucleation centers (or oxygen precipitates) increases from the first face to the region of maximum density and decreasing from the region of maximum density to the central plane.

Abstract: A process for treatment of a silicon wafer to achieve therein a controlled distribution of the density of oxygen precipitate nucleation centers. In the process, one face of the wafer is shielded and the other, unshielded, face of the wafer is exposed to an atmosphere which contains nitrogen or a nitrogen compound gas and which has an essential absence of oxygen during a rapid thermal treatment at a temperature of at least about 1175.degree. C. The process generates nucleation centers which serve as sites for the growth of oxygen precipitates during a subsequent heat treatment and which have a peak density proximate the unshielded face of the wafer.