Infrared studies of amorphous carbon films formed by plasma decomposition of acetylene

Abstract

Thin films of amorphous hydrogenated carbon have been deposited by radio frequency (RF) glow discharge decomposition of various mixtures of acetylene and hydrogen gases. The films were grown on silicon substrates kept on both the powered and grounded electrodes. These films were annealed in vacuum in a temperature range of 300-600° C. Infrared spectroscopy has been used to find the hydrogen content and also the structural changes associated with the annealing process. It has been shown that the hydrogen content in the film is very sensitive to the process parameters. The annealing process results in a near hydrogen-free film. The microstructure of the films is related to the process parameters and the annealing temperature.