[Atomic hydrogen emission line and the high quality diamond film]

The process of atomic hydrogen emission in CH4/H2 gas mixture in EACVD is simulated by Monte Carlo method. In the simulation two basic types of collision between electron and H2 molecule are considered: elastic collision and inelastic collision. Four types of inelastic processes have been considered, namely vibrational excitation, dissociation, electron excitation (contains Halpha, Hbeta and Hgamma) and ionization. For e-CH4 collision, elastic momentum transfer, vibrational excitation, dissociation, dissociative excitation (contains Halpha, Hbeta and Hgamma), ionization and dissociative ionization are considered. The relationship between the number of H, CH3 and the ratio of atomic hydrogen emission line intensity under different experimental conditions is investigated. A method to obtain the optimum experimental condition for diamond deposition by the atomic hydrogen emission line is given. The result is of great importance to depositing high quality diamond films by controlling the conditions of technology efficiently.