HIGH-PRESSURE CHEMICAL-VAPOR-DEPOSITION FOR PREPARATION OF CARBON

A chemical vapor deposition (CVD) apparatus under high gas pressure up to 1.0 MPa was experimentally fabricated. The high-pressure CVD with methane as raw material gas and argon as carrier gas was carried out, and carbon film was obtained on a graphite substrate at temperatures of 1673 to 2373 K and total gas pressure 40 KPa to 1.0 MPa. In the experimental pressure range, as total gas pressure increases, the weight of carbon film formed on the graphite substrate increases, and the density of the film was increased from 1.30 x 10(3) kgm(-3) to 2.15 x 10(3) kgm(-3). The X-ray diffraction and Raman spectroscopic analysis indicated that disorder structure of the film decreased and, also, the graphitization degree advanced with total gas pressure. SEM observation indicated that the c-axis direction of the crystallites was not always oriented vertically to the deposited surface.