Thermal Stability of Magnetron Sputtered Low HydrogenContent Diamondlike Carbon

Response to vacuum annealing at temperatures up to 600°C for 3h for low hydrogen content diamondlike carbon (LHDLC) films prepared by magnetron sputtering of pure graphite in pure Ar atmosphere has been studied. Optical properties of the as-deposited and annealed films have been characterized by ellipsometry and infrared spectroscopy. No change was found for the films annealed at up to 400°C. The LHDLC begins losing hydrogen after annealing above 400°C and the sp² hybrid structure increases. The refractive index of the films increases with increasing annealing temperatures above 500°C. Annealing at 600°C results in graphitization and the loss of IR transparency.