High vacuum chemical vapor deposition of cubic SiC thin films on Si(001) substrates using single source precursor

Thin films of cubic SiC have been prepared on Si(001) substrates in situ by high vacuum metal-organic chemical vapor deposition (HVMO-CVD) method using a single source precursor at various growth temperatures in the range of 300–1000°C. 1,3-Disilabutane, H3Si-CH2-SiH2-CH3 (DSB) that contains the same amount of silicon and carbon atoms in the same molecule was used as precursor without carrier gas. During HVMO-CVD, moreover, a series of as-deposited SiC/Si(001) thin films were simultaneously characterized by in situ X-ray photoelectron spectrometry (XPS) under the UHV condition without air exposure. XPS and Rutherford backscattering spectroscopy (RBS) show that the SiC films grown at above 700°C have stoichiometric composition. However, the films grown at below 700°C show Si-rich stoichiometry. Transmission electron microscopy (TEM) confirms the crystalline nature of the SiC films. The optimum temperatures for the formation of the epitaxial 3C–SiC thin films were found to be between 900 and 1000°C on the basis of XRD and TED analysis. In this study, the best film with maximum growth rate of 0.1 μm/h was obtained from a SiC film grown at 900°C and 8.7×10−4 Pa of DSB. The SiC/Si interface is clearly shown in secondary ion mass spectroscopy (SIMS) depth profile as judged by the sharp decrease 13C signals. The thickness of the as-grown films was determined using cross-sectional scanning electron microscopy (SEM) and RBS, and two different activation energies for 3C–SiC formation were obtained from the Arrhenius plots.