Ryusuke Nakai

Thermoelastic Analysis of Slip Defect Generation on GaAs Wafers.

In this work we develop the thermoelastic analysis for prediction of slip defect generation on (001) GaAs wafers, by means of the finite element method taking into account the anisotropic structure and slip system of dislocation. The analysis for a completely circular wafer predicts that longer slip defect lines are generated at the wafer edge of θ=π/8+Δ+nπ/2, 3π/8-Δ+nπ/2 (Δ is about 3°) and the prediction well agrees with the result of the wafer heating experiment. This demonstrates that our anisotropic analysis is more accurate than simple isotropic analysis which predicts slip defect generation at the wafer edge of θ=π/8+nπ/4. According to this thermoelastic analysis, we can additionally confirm that longer slip defect lines are more prone to be generated at the orientation flat (OF) edge than at the circular edge. Finally, we suggest the method of preventing slip defect generation.

Improvement of microscopic and macroscopic uniformity in 4-inch InP substrate for IC application by vertical boat growth

Macroscopic and microscopic uniformity in 4-inch InP substrates has been significantly improved by new developments in SEIs Vertical Boat (VB) technique. In this paper, we report improvements, in etch-pit density (EPD) distribution, micro-resistivity profiles, and photoluminescence (intensity and 4.2K spectra), for 4-inch InP VB in comparison to both VCZ (SEI proprietary Vapor pressure controlled Chockralski) and commercially available VGF substrates.