DEVELOPMENT OF NONDESTRUCTIVE BULK MICRO-DEFECT ANALYZER FOR SI WAFERS

A non-destructive and non-contact observation method was developed to detect defects in Si crystals. By this method, cross-sectional images of the defects in a crystal are obtained. There are functions for both horizontal and vertical cross sections. It is found that this method is effective for revealing near-surface defects, precipitates within the denuded zone of intrinsic gettering-treated wafers, twins or slip plane defects in epitaxial layers, and defects on the layer boundaries in SOI (SIMOX, etc.) wafers. The observed results were compared with results detected by conventional laser scattering tomography and in some cases inconsistencies were noticed.