Atmospheric pressure chemical vapour deposition of amorphous silicon carbide thin films onto fused quartz.

摘要

Thin films of amorphous SiC have been prepared on quartz substrates by chemical vapour deposition (CVD) method using a single source precursor gas at atmospheric pressures. The precursor gas used was Trimethylsilane, with argon as the carrier gas. The deposition was conducted at low temperatures in the range of 720 to 760°C for 10 to 60 minutes, using constant gas flow rates. Films were annealed at 900°C, 1000°C, and 1100°C for 2 hours in an argon atmosphere. Optical and SEM micrography was used to image the surface and the cross section of the films and to determine film thickness. Film composition was studied by TEM/EDS methods. Glancing angle X-ray diffraction (GAXRD) was used to characterize the crystallinity of the films. Nanoindentation was used to determine micromechanical properties of the films.; TEM/EDS results, when referenced to bulk SiC, show the films to be stoichiometric SIC. GAXRD spectra showed that the films were entirely amorphous, eve after heat treatment to 1100°C. Hardness and reduced Young's modulus values as high as 18 GPa and 108 GPa, respectively, were achieved for as-deposited films. Hardness values were found to increase from 16.1 GPa to 19.5 GPa for heat treated films.