Characterization of silicon on insulator substrates using reflection mode double-crystal X-ray topography

Abstract

The strain distributions of various silicon-on-insulator (SOI) wafers were studied using Bragg reflection mode double-crystal topography analysis. These SOI samples included the separation by implanted oxygen (SIMOX), the zone melt recrystallization (ZMR), and the bond and etch-back silicon-on-insulator (BESOI). The inherent warpage of each SOI sample was revealed by X-ray double-crystal topography (DCT). Dislocation loops and surface-terminating defects were also observed on the ZMR sample. The defect density was evaluated by double-crystal rocking curve (DCRC) analysis using a symmetric (004) set-up. The relative peak intensities and full width at half maxima (FWHM) were measured. The quality of superficial silicon layers of most SOI wafers was similar to the quality of a single-crystal silicon, except the ZMR sample. According to these analyses, SIMOX wafers provide the best single-crystal quality and consistent lattice characteristics under various fabrication processes.