Off c-Axis Bulk Crystal Growth of Silicon Carbide

This Phase I program is aimed at demonstrating the principle of off c-axis boule growth of 4H-SiC. In Phase I, using off-axis SiC seeds, we will demonstrate the growth of 4H-n SiC boules~15 mm long. Also in Phase I, we will slice the off-axis boules intowafers, lap and polish them, and perform structural and electrical characterization of the wafers. Comparisons will be made with on-axis wafers for micropipe and planar defect densities and their distributions. The off-axis grown wafers are expected tooffer significant advantages for device processing and fabrication. In Phase II, improvements will be made to the growth process, and we will demonstrate the production of commercially feasible, large diameter off-axis 4H-n SiC wafers with reduced defectdensity.The proposed off-axis boule growth offers specific advantages: (a) off-axis wafers are directly produced by slicing the boule perpendicular to the axis of the grown cylindrical boule and hence the wafer yield is considerably higher than thatproduced by on c-axis grown boules, (b) the cost of off c-axis wafers will be significantly lower, (c) the quality of wafers will be superior due to decreased defect density.