Low Temperature Diamond Synthesis Using Microwave Plasma CVD.

Abstract

Diamond films were grown at low temperatures (630-813K) on Si, Al (1100P), and Al-Si (8A, 8B, 8C) alloy substrates using microwave plasma chemical vapor deposition (CVD) in a mixed methane and hydrogen gas reaction system.When the methane concentration was high and growth was conducted at lower pressures the diamond films were synthesized and the deposits on the scratched substrates formed flat surfaces consisting of fine grains.XRD results, confirmed that the deposits were cubic diamond. An analysis using Raman spectroscopy, further confirmed that diamond films deposited on the Si substrates were of high quality. The deposits on the Al substrates, in contrast, contained amorphous carbon. While the quality of the deposits on the Al-Si alloy substrates were differed with the substrate alloy. We assume that this phenomenon was caused by the chemical components of the individual substrates.Viewed from a comparison of the individual substrate growth conditions, the mechanism underlying low-temperature-growth diamond synthesis thus appears to consist of an overlapping of factors such as Te, Tg, Ne, and the carbon source concentration complex from comparison of their growth conditions.