EVALUATION OF MECHANICAL DAMAGE BY HIGH-RESOLUTION X-RAY-DIFFRACTION AND MINORITY-CARRIER RECOMBINATION LIFETIME IN SILICON-WAFER

In Czochralski silicon wafers, the effect of mechanical back side dama ge was systematically analyzed by x-ray diffuse scattering and minorit y carrier recombination lifetime measurements. X-ray section topograph y and wet oxidation/preferential etch methods were also employed. A li quid honing method was used to induce mechanical damage, and the damag e grade was varied by controlling process parameters. A high resolutio n x-ray analysis of the samples was carried out before and after heat treatment at 1100 degrees C for 60 min. The magnitude of diffuse scatt ering was analyzed quantitatively by integrating the excess intensity of diffuse scattering into a reciprocal space map and its correlation with the mechanical damage was examined. As the grade of mechanical da mage increased, the degree of diffuse scattering increases and minorit y carrier recombination lifetime decreases, suggesting the generation of more defects. We discuss other experimental results from the viewpo int of the structure-property relationship. (C) 1998 American Institut e of Physics.