3C-SiC bulk growth: Effect of growth rate and doping on defects and stress

We report the study of the effect of the growth rate and of the doping on the stress and the defect density of a Cubic Silicon Carbide (3C-SiC) bulk layer grown at low temperature on a silicon substrate. After the growth process, the silicon substrate was melted inside the CVD reactor used for the deposition and then the intrinsic stress was measured by the curvature of the wafer without influence of the thermal stress between silicon and 3C-SiC. A considerable increase of the curvature was observed increasing the doping of the layer. The average stress is compressive and then produces a convex bow. At the same time, the average quality of the grown material deteriorates increasing the doping concentration. Using ?-Raman measurement in cross-section of the 3C-SiC grown samples, it was possible to observe the dependence of the stress and of the quality of the material as a function of the thickness and of the growth rate, due to the variation of the growth rate during the process. In particular, the increase of the growth rate produced both an increase of the stress and a decrease of the material quality. Furthermore, the increase of the doping concentration produced both an increase of the stress and a further deterioration of the crystal quality.