Elimination of Oxidation‐Induced Stacking Faults by Preoxidation Gettering of Silicon Wafers: I . Phosphorus Diffusion‐Induced Misfit Dislocations

Abstract

In the present paper a preoxidation gettering procedure (called POGO) is described which prevents the formation and/or activation of stacking fault nucleation sites during oxidation. In this way the stacking faults and their possible device degrading influences are eliminated at the start of a processing schedule. In addition, the gettering medium is retained through all subsequent high temperature processing, thereby continuing to suppress the formation of stacking faults. The gettering of the nucleation sites, whether they be process induced, such as impurity precipitation, or native to the original crystal growth, such as vacancies or impurities, is achieved by the controlled introduction of interfacial misfit dislocations on the back side of the wafer. The dislocations interact with the stacking fault nucleation sites such that the nuclei diffuse from the active device side of the wafer to the line defects which are confined to within a few microns of the back surface.