Formation of a-C thin films by plasma-based ion implantation

Carbon films were prepared on a Si wafer substrate by using a plasma-based ion implantation (PBII) technique. The homogeneity of the carbon films formed on the three-dimensional object and the influence of the duty ratio of the pulse bias to the target on the property of the carbon films were investigated. The homogeneity of the carbon films formed on a convex face and that formed on a concave face by the incidence of the microwave to the target with a low angle of about -30 degrees was almost a constant. The application of the ECR plasma source, with a mirror field, to the PBII system was efficient enough to improve the homogeneity, even though the plasma density was not very high. Diamond-like carbon films with a flat surface and a low friction coefficient can be formed by applying negative high-voltage pulses to a substrate with a low duty ratio of 1%. (C) 2001 Elsevier Science Ltd. All rights reserved.