Ideal oxygen precipitating silicon wafers

摘要

A process for heat-treating a single crystal silicon wafer (1) to influence the precipitation behavior of oxygen in the wafer in a subsequent thermal processing step. The wafer has a front surface (3), a back surface (5), and a central plane (7) between the front and back surfaces. In the process, the wafer is subjected to a heat-treatment (S2) to form crystal lattice vacancies (13), the vacancies being formed in the bulk of the silicon. The wafer is then cooled from the temperature of the heat treatment at a rate which allows some, but not all, of the crystal lattice vacancies to diffuse to the front surface to produce a wafer having a vacancy concentration profile in which the peak density is at or near the central plane with the concentration generally decreasing in the direction of the front surface of the wafer. <IMAGE>