Process for the preparation of silicon wafers having controlled distribution of oxygen precipitate nucleation centers

A process for treatment of a silicon wafer to achieve therein a controlled distribution of the density of oxygen precipitate nucleation centers comprising the steps of:

• exposing an unshielded face of the wafer to an atmosphere which contains nitrogen or a nitrogen compound gas during a rapid thermal treatment at a temperature of at least about 1175.degree. C. for a period of between about 3 and about 60 seconds while shielding the other face of the wafer from the atmosphere during the rapid thermal treatment, and
• allowing the thermally treated wafers to cool at a rate of at least about 5.degree. C. per second,
• to generate nucleation centers which serve as sites for the growth of oxygen precipitates during a subsequent heat treatment, the nucleation centers having a peak density proximate the unshielded face of the wafer.

A process for treatment of a silicon wafer to achieve therein a controlled distribution of the density of oxygen precipitate nucleation centers comprising the steps of:

• exposing an unshielded face of the wafer to a nitrogen atmosphere during a rapid thermal treatment at a temperature of at least 1200.degree. C. while shielding the other face of the wafer from the atmosphere during the rapid thermal treatment to generate nucleation centers which serve as sites for the growth of oxygen precipitates during a subsequent heat treatment, the nucleation centers having a peak density proximate the unshielded face of the wafer.