Characteristics of poly-crystalline 3C-SiC thin films grown for micro/nano-electromechanical systems by using single-precursor hexamethyidisilane

This paper presents the growth conditions and characteristics of poly-crystalline 3C-SiC thin films for micro/nano-electromechaical systems (M/NEMS) applications. The growth of the polycrystalline 3C-SiC thin film on an oxided Si wafer was carried out by using atmospheric pressure chemical vapor deposition (APCVD) with a single-precursor of hexamethyldisilane (HMDS: Si-2(CH3)(6)). This work was done for deposition conditions; the growth temperature and the HMDS flow rate were adjusted from 1000 to 1200 degrees C and from 6 to 8 sccm, respectively. Each sample was analyzed by using X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), and reflection high energy electron diffraction (RHEED) to obtain an optimized growth temperature. A scanning electron microscopy (SEM), which measures the layer density, voids, and dislocations in a cross-section, was also used to obtain an optimized HMDS flow rate. Moreover, X-ray photoelectron spectroscopy (XPS) and glow discharge spectrometry (GDS) were used to evaluate the stoichiometry of the poly-crystalline 3C-SiC films, and the atomic ratio between Si and C was 1 : 1 from the surface to the interface. Finally, the effect of H-2 addition was studied to reduce to surface roughness, and atomic force microscopy (AFM) and tunneling electron microscopy (TEM) were used to investigate the surface roughness and the SiC/SiO2 interface, respectively. From the results, the optimal growth conditions for the poly-crystalline 3C-SiC thin film were a deposition temperature of 1100 degrees C, a HMDS flow rate of 8 sccm, and a H-2 flow rate of 100 sccm. The grown poly-crystalline 3C-SiC films had very good crystal quality without twins, defects, and dislocations.