AVS 46th International Symposium
    Vacuum Metallurgy Division Tuesday Sessions
       Session VM-TuP

Paper VM-TuP2
Growth of SiC Thin Films on Graphite for Oxidation Protective Coating

Tuesday, October 26, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: J.-H. Boo, SungKyunKwan University, Korea
Authors: J.-H. Boo, SungKyunKwan University, Korea
M.C. Kim, SungKyunKwan University, Korea
C.H. Heo, SungKyunKwan University, Korea
S.-B. Lee, SungKyunKwan University, Korea
S.-J. Park, SungKyunKwan University, Korea
J.-G. Han, SungKyunKwan University, Korea
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We have deposited thick SiC thin films on graphite substrates in the temperature range of 700 - 850 @super o@C using single molecular precursors by both thermal MOCVD and PEMOCVD methods for oxidation protection wear and tribological coating. Two organosilicon compounds such as diethylmethylsilane (DEMS), (Et)@sub 2@SiH(CH@sub 3@), and hexamethyldisilane (HMDS), (CH@sub 3@)@sub 3@Si-Si(CH@sub 3@)@sub 3@, were utilized as single source precursors, and hydrogen and Ar were used as a bubbler and carrier gas. Highly oriented polycrystalline cubic SiC layer in [110] direction was successfully deposited on graphite at temperature as low as 800 @super o@C with HMDS by PEMOCVD. In the case of thermal MOCVD, on the other hand, only amorphous SiC layers were obtained with either HMDS or DEMS at 850 @super o@C. From this experiment, we confirmed that PEMOCVD was highly effective process in improving the characteristics of the SiC layer properties compared to those grown by thermal MOCVD. The as-grown samples were characterized in situ with OES and RGA and ex situ with XRD, XPS, and SEM. The mechanical and oxidation-resistant properties have been checked. The optimum SiC film was obtained at 850 @super o@C and RF power of 200 W. The maximum deposition rate and microhardness are 2 µmm/h and 4,336 kg/mm@super 2@ Hv, respectively. The hardness was strongly influenced with the stoichiometry of SiC protective layers. Ar-plasma pre-treatment enhanced the hardness and adhesion between SiC layer and graphite substrate due to a nucleation effect.