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A variety of defect-sensitive techniques are employed to detect, identify and quantify the residual impurities and native defects in high-purity 6H-SiC crystals grown by halide chemical-vapor deposition technique. The incorporation efficiencies of N and B are determined by the site-competition effect.

The effects of Si doping on the evolution of stress in [Al.sub.x][Ga.sub.1-x]N:Si thin films grown on 6H-SiC by metal organic chemical vapor deposition are examined by using in situ water curvature measurements. The model describing tensile stress generated by dislocation effective climb is modified for accounting for the dislocation reduction and has produced an improved fit to the experimental stress-thickness data.

A thermodynamic model for predicting the boundary between deposition of SiC and deposition of a mixture of C and SiC, where SiC is the only condensed phase produced during halide chemical vapor deposition (CVD) growth, is proposed. It is observed that the changes in precursor concentration, [H.sub.2] concentration, temperatures, pressure and Cl concentration have influenced the position of the phase pure boundary.

High-purity 6H-SiC single crystals were grown by the halide chemical-vapor deposition process. Growth was performed in a vertical hot-wall reactor with a separate injection of a silicon precursor and a carbon precursor.

Abstract: The stress evolution of Si-doped Al x Ga1−x N epilayers with x ranging from 0 to 0.62 was examined using an in situ wafer curvature measurement technique. Transmission electron microscopy was used to assess the effects of Si concentration and composition on defect microstructure. It was found that the density of edge-type threading dislocations (TDs) increased with increasing x, corresponding to the evolution of higher magnitudes of tensile stress, attributed to TD inclination. The results are discussed in the context of proposed inclination mechanisms that feature jog formation as the process leading to TD inclination. [Copyright &y& Elsevier]