Preparation Of Diamond-like Carbon Film By Plasma Enhanced Chemical Vapor Deposition And Its Nano-mechanical Properties

During the past two decades, diamond-like carbon (DLC) films have attracted an overwhelming interest from both industry and the research community. There are mainly two methods of preparing DLC films: physical vapor deposition and chemical vapor deposition. Especially, Plasma Enhanced Chemical Vapor Deposition (PECVD) is a brand new method to prepare DLC films in recent years, and it has very preeminent prospect in the industrial application. But the properties of DLC films are affected by various process parameters in preparing process. Therefore, in this paper, we focus on optimizing the process parameters (e.g. deposition pressure, deposition time, RF power and bias voltage) of preparing DLC films so that we can obtain the excellent quality of DLC films.Firstly, we prepared DLC films under different process parameters by PECVD device. Secondly, atomic force microscope was adopted to investigate the surface morphology of DLC films, and measure their friction force and coefficients. Finally, the hardness and Young's modulus were investigated by nano-indenter, to evaluate their mechanical properties.The conclusions showed that increasing deposition pressure can improve the frictional properties of DLC films stably, but will decrease the hardness and Young's modulus. Affected by other parameters (such as RF power), DLC films perform better or worse frictional and mechanical properties while increasing deposition time. Consequently, improving the quality of DLC film only by increasing or decreasing deposition time exclusively is risky. RF power takes little effect on the frictional properties of DLC films, and there are some critical points that the influential trend of frictional properties by RF power will be reversed when these points are reached. Therefore, more attention must be taken in the industrial application. The frictional and mechanical properties of DLC films all can be improved by increasing bias voltage. But dependence between ultra high bias voltage and performance of DLC film is not involved in this paper.This research will improve the preparation of DLC films under various industry areas, and provide the good experience for study and basis for further industry application.