CVD diamond film oxidation resistance research

Abstract

Diamond films were deposited on a silicon substrate by microwave plasma chemical vapor deposition system, and its oxidation experiments were carried out in atmospheric environmental condition by using a muffle furnace. Inatmospheric environment (the temperature is from 400°C to 900°C) the oxidation resistance of diamond thin films was investigated. The results indicate that under the atmospheric environment diamond thin film surface morphology did not change after 6 hours at 400°C. Diamond thin film surface morphology began to change after 2 hours at 600°C, and when time was extended to 4 hours, the diamond thin film surface morphology changed significantly. The surface morphology of diamond films began to change after 15 minutes at a 700°C condition and when time was extended to 6 hours diamond films were all destroyed. All the diamond films on the silicon substrate disappeared completely in 20 minutes at 900°C. The intact crystal face is the reason that natural diamond has stable chemical property. The crystal face of synthetic diamond film has a lot of defects, especially on the side. Oxidation of the diamond films begin with the grain boundary and defects.