PREPARATION OF AMORPHOUS-CARBON THIN-FILMS BY ION-BEAM-ASSISTED ECR-PLASMA CVD

Amorphous carbon thin films have been deposited on austenitic type sta inless steel, glass and silicon wafer substrates by ion beam assisted ECR-plasma CVD from CH4 gas as precursors. During the deposition the f ilms were irradiated with Ar ions with an acceleration voltage of 0.5- 4 kV. The composition and structure of the films were investigated by Raman and Fourier Transform Infrared (FT-TR) spectroscopies. The hardn ess and friction coefficients of the films were estimated by a dynamic ultra micro-hardness tester and a reciprocating sliding tester, respe ctively. The results showed that the structure and properties of the f ilms strongly depended on the ion energy and the current density. The structure of the films changed from polymer to amorphous carbon with i ncreasing ion energy and ion current density and the films were mainly composed of sp(3) and sp(2) carbon bonded to hydrogen. The integrated intensity ratio of amorphous carbon and disordered graphite structure , I-D/I-G, increased from 0.6 to 1.9 with current density. The carbon films irradiated with high ion energy showed high hardness and a very low friction coefficient of 0.035.