Growth of large-scale heteroepitaxial 3C-SiC films and nanosheets on silicon substrates by microwave plasma enhanced CVD at higher powers

Abstract

Abstract The controllable growth of heteroepitaxial cubic SiC (3C-SiC) films and two dimensional (2D) nanosheets arrays has been successfully achieved using a 915 MHz microwave plasma enhanced chemical vapor (MPCVD) deposited technique using tetramethylsilane (TMS) and hydrogen as the resource gases. A comprehensive analysis of the surface morphology of the 3C-SiC films was performed by tuning microwave power, TMS flow rate and gas pressure. With increasing microwave power, the morphology of the SiC crystals evolves from randomly oriented nanocrystals to well-oriented pyramid shaped crystals. The rocking curve results shows that the 3C-SiC film deposited at microwave power of 9 kW and gas pressure of 50 mbar remains epitaxial feature with increasing of TMS gas flow rate. As a result, uniform heteroepitaxial 3C-SiC film was deposited on 4-in. silicon wafer at low deposition temperature (~ 860 °C). The structure of SiC film along the radial direction was measured by X-ray diffraction (XRD) results. X-ray photoelectron spectroscopy (XPS) spectra indicate the chemical information of SiC film surface and the depth profiles, which prove the uniform of elements distribution. Moreover, with increasing gas pressure, the film morphology transforms from the heteroepitaxial SiC film into 2D nanosheets, which is due to the increased ion current.