Plasma assisted process for deposition of silicon carbide thin films

Silicon carbide (SiC) thin films were deposited on silicon substrate by the RF plasma chemical method, operating at a frequency of 13.56 MHz. Two different plasma assisted chemical vapor deposition (CVD) technologies were attempted: direct plasma CVD with reaction gas of CH3SiCl3 and remote plasma CVD with SiH4 + C3H8. The film deposition rate of SiC was linearly increased with the plasma power when the substrate temperature was fixed to 300 °C. The measurement of the photon absorption reveals that the band gaps of the electron energy state were to be 2.39 eV for Si0.5C0.5, and 2.51 eV for Si0.4C0.6, respectively. In the high-density regime of the RF plasma, the methyl-radicals decompose easily and increase the carbon concentration in the plasma and result in the growing films. The yield of the remote plasma CVD was estimated as 70.8% when the flow rate of SiH4 + C3H8 gases was kept to 15SCCM and 10SCCM, respectively. The deposition of SiC films with remote plasma CVD followed by a laser treatment would be the optimal process technology to obtain the high quality poly-crystalline SiC film.