Deposition And Growth Mechanism Of Crystalline Carbon Nitride Thin Films

The properties of crystalline carbon nitride films (CN) on silicon substrate have been explored experimentally by the PE-PLD and PE-CVD method. The relation between different deposition parameter and the structure properties of CN compound films is analyzed; the deposition mechanism of the CN films is studied.CN thin films with up to 21at% nitrogen content have been prepared by PLD method. The effect of the substrate temperature and the reactant pressure on the structure properties of thin film is studied. The reason why the crystalline CN deposited films present the local characteristics is explained, A feasible method which increases the content with sp3 bonding structure and the total nitride content in the deposited films has been given by introducing pulsed glow discharge plasma enhanced gas phase reaction in PLD process. The crystalline CN thin films with 56 at% N have been obtained from CH4+H2 gas with assistant H2 using the PE-CVD method. The properties of CN thin films such as their morphology, component, crystal structure and the bonding structure and the relation between those properties and the gas-phase reaction parameters were discussed, showing that the deposition of P-C3N4 thin film is the compete result of various reaction processes in the dynamics balance conditions; the process of CN films deposition is diagnosed in situ through the optical emission spectra technique,, the effects of experimental parameters on the concentration of the precursors and the gas-phase reactions in the plasma have been obtained; the main reaction precursors for film deposition identified; the relation between the characteristics of CN thin films and the reaction process in the plasma is analyzed. The CN thin films deposition under different substrate temperatures in high pressure PE-PLD shows that the Si atom of the substrate has participated the CN films growth process, Based on this the growth mode of CN thin films on the Si substrate is proposed. The further experiment of CN thin films deposition on Si substrate scratched by diamond as well as covered with Fe catalyzer has been attempted, which indicates that changing the dynamics conditions of the surface reaction can alter the growth characteristic of the CN thin films and can enhance obviously the films growth rate.