Microstructural study of residual stress in chemically vapor deposited β-SiC

Silicon carbide was chemically vapor deposited (CVD) on isotropic pyrolytic graphite substrates by using methyltrichlorosilane as the source gas and hydrogen as the carrier gas. Transmission electron microscopy was used to observe microstructural defects in CVD β-SiC caused by residual stresses. Microstructures resulting from recovery and annealing effects during the deposition processes were also observed and are discussed. The magnitude of residual stress between deposition temperatures of 1400 and 1600°C decreased from about 2000 to about 250 MPa, estimated by the wafer central deflection method.