论文部分内容阅读
A global plasma model has been developed to describe the MPPMS discharge process based on the particle balance and the energy balance in the ionization region. In addition, considering the increased complexity introduced by the reactive working gas, and the formation and loss of compound at the target surface, the model is extended to the reactive MPPMS discharges. The modeling results show that, in the Cu thin film deposition process by MPPMS discharges, as increasing the working pressure from 0.1 to 0.7 Pa, the modeled electron temperature decreases from 6-8 eV to about 4 eV, the effective power transfer coefficient, which represents the power fraction that effectively heats the electrons and maintains the discharge, decreases from 7-9% to 6%. In the TiAlSiN thin film deposition process by reactive MPPMS discharges, as increasing the N2 partial pressure from 0% to 40% at constant working pressure of 0.3 Pa, the electron temperature during strongly ionized period increases from 4 eV to 7 eV, the effective power transfer coefficient increases from about 4% to 7%; as increasing the working pressure from 0.1 to 0.7 Pa at constant N2 partial pressure of 25%, the electron temperature decreases from 10.5 to 4 eV, the effective power transfer coefficient decreases from 8% to 5%. Using the modeled plasma parameters to evaluate the kinetic energy of arriving ions and the substrate temperature, the variations of processing parameters which decrease both values lead to a weakened diffusion ability of adatom and a reduced input energy to the substrate, corresponding to the observed transition of the deposited Cu thin films from a void free structure with a wide distribution of grain size into an underdense structure with a fine fiber texture in the extended structure zone diagram, the increase of intercolumnar voids and the surface roughness, as well as the decrease of grain sizes; for the deposited TiAlSiN thin films, corresponding to the increase of surface roughness, the microstructure transition from dense glassy structure to columnar structure, and the reduction of phase separation. The increase of electron temperature shifts the discharge balance of Ti species from Ti+ to Ti2+, which has a higher return fraction, results in a higher Al/Ti ratio of the deposited TiAlSiN thin films. The composition and microstructure transition of deposited thin films are well-explained by the modeling results, suggesting that the primary plasma processes are properly incorporated in the model. The results contribute to the understanding of the characteristics of MPPMS discharges, as well as its correlation with the composition and microstructure of deposited thin films.