SiC heteroepitaxial growth by low pressure chemical vapor deposition on Si(111) substrates

Abstract 3C-SiC was heteroepitaxially grown on Si(1 1 1) substrates by the low pressure chemical vapor deposition (LPCVD) with a gas mixture of silane, ethane and hydrogen. Under the very low pressure of 30 Pa, we got good single-crystalline SiC films at a low temperature of 900 °C, much lower than the typical deposition temperature above 1200 °C found elsewhere. Their characteristics and crystallinity were examined by X-ray diffraction, infrared absorption, and auger electron spectrum (AES). The SiC peak was found at a 2θ value of 35.8°. The full width at half maximum (FWHM) is only 0.28°, indicating that the SiC film is single crystalline. In the FTIR absorption a peak at 800 cm−1 is observed. In the AES depth profile the film is composed of Si and C with a composition very close to that of stoichiometric SiC. The surface morphology of the film was examined by AFM. These images show the good crystalline of SiC at the surface, and the surface image of a film grown at the initial stage was also observed in order to study the growth mechanism at low temperature and low pressure.