Modeling and analysis of hydrogen–methane plasma in electron cyclotron resonance chemical vapor deposition of diamond-like carbon

Abstract

Diamond-like carbon films were deposited using the electron cyclotron resonance chemical vapor deposition (ECR-CVD) system. A model for the ECR plasma was formulated using deposition parameters, such as microwave power, pressure, and hydrogen/methane ratio as inputs. Using the model, electron energy, rate constant of electron impact reactions, and density of species in the plasma are calculated. The outputs of the model are analyzed as a function of deposition conditions, such as microwave power, pressure, and hydrogen/methane ratio and compared to experimental data measured using a Langmuir probe. The results show that ion density increases following the increase in microwave power and hydrogen/methane ratio, and decreases following the increase pressure. Results from the model are in agreement with experimental data, and show that the main neutral species are H2, CH4, H, CH3, CH, C2H5, CH2, and C2H6. The main ionic species are H2+, CH4+, CH3+, CH2+, H+, CH5+, C2H4+, C2H5+, and CH+.