低气压等离子体合成功能薄膜的部分机理研究

In the low-temperature plasma processes, the depositing rate, properties, and the structures of the films depend on the plasma parameters and the characteristics of the plasma sheath near the substrates. In this project, we have studied experimentally and theoretically the characteristics of the plasma sheath and the properties and the structures of the deposited films, respectively. .(1) Using the different methods, such as the surface-wave PCVD、laser ablation, and intense pulse ion beam ablation, we have deposited the DLC films with high sp3 bonds, and studied the influence of the substrate temperature, the biased voltages, discharge powers, and the discharge pressures on the properties and the structures of the deposited films with the Raman,SEM,and XPS. .(2) Using the micro-wave ECR plasma source, we have deposited the CNx films with the higher microhardenness，and studied the relations between he properties and the structures of the deposited films and micro-wave power, the work current, the work pressure, the gas flux, and the sputtering voltage. .(3) Using the ECR-PECVD，we have deposited the SiO2 films and studied the influence of the rf biased voltage on the depositing rate，the chemical computation, and the refractive index of the deposited films. It has been found that as increasing the rf biased voltage, the depositing rate increases and the film roughness becomes large. .(4) A self-consistent theoretical model of the rf plasma sheath near the substrates has been established to simulate the temporal-spatial evolutions of the electric field and the charged densities within the sheath, and the energy distributions and angle distributions of ions bombarding on the substrate surfaces. It has been found that the ratio of the rf source frequency to the plasma ion frequency is an important physical parameter that affects the temporal-spatial evolutions of the sheath and the ion energy distributions. Using the single probe, the emission spectrum, the fluorescence spectrum induced by the laser, and the mass spectrum of the molecular beams, we have diagnosed the plasma parameters during the processes of the depositing the DLC, CNX and SiO2 films..(5) The molecular dynamics (MD) simulation has been used to simulate the interactions of hydrocarbon radicals (C2H2, CH3 and C-clusters ) in plasmas with substrate surfaces, and chemisorption dynamics. The growth process and the structure character of the synthesized DLC films were also investigated. It was found that the sp3 ratio in the films would be greatly affected by changing the depositing species and, especially, their incident energy. Our result supports the experimental findings. In addition, the simulation explains the experimental observation at atomic level..（6）We have developed a inductively-coupled plasma source which is used to functional deposit films..

采用等离子体化学气相沉积方法合成硬质碳膜和氧化膜；研究近表面区等离子体鞘层的演化过程及表面效应对它的影响；研究表面原子的沉积过程及薄膜生长的机制；研究等离子体鞘层物理参数、外部工艺参数及化学反应过程对合成薄膜的性能及结构的影响，优化薄膜的合成工艺，为低气压放电等离子体合成功能薄膜材料提供理论指导。