Study On Influence Of Surface Defects In Silicon Based Materials On Polishing Quality In Atmospheric Plasma

Silicon-based semiconductor materials are applied more and more in the fields of aerospace, defense and civil for their excellent properties, such as high thermal conductivity, high bonding energy, high breakdown voltage and so on. But the surface quality is also put forward higher request, which brings serious challenges to the processing technology. In practical applications, the defects are widespread in the silicon-based materials, there are little theoretical models and experimental methods for them. The existing researches are mainly to analyze silicon-based materials with complete lattice, which often ignore the influence of defect in crystal on the polishing process.The research content of this paper was the influence of defects in silicon based materials on the polishing process by using atmospheric plasma. The edge dislocation and screw dislocation were analyzed as typical structures by using quantum chemical simulation calculation method, which were the most common defects. 4H-Si C supercell structure and models containing two typical dislocation were established, the conclusion that existence of dislocation would promote the etching was revealed by comparing the density of states, the average number of electrons, activation energy and energy of barrier, which was verified by experiment. Two kinds of samples was tested, whose dislocation density were different. The parameters such as removing content and surface morphology were analyzed by using plasma polishing under the same process parameters, after which the conclusion that the existence of the dislocation could improve the efficiency of the machining was obtained. It validated the theoretical simulation results. Reside function model was revised by considering the theoretical simulation results and experimental testing data of dislocation structure. Polishing processing experiment was carried out, which achieved the theory predicts and processing compensation for the influence of dislocations.This paper revealed the influence of defects in crystal on the polishing process by using atmospheric plasma, which was discussed by theoretical simulation and experimental analysis. Reside function model was revised by using the conclusion,which helped to improve the machining accuracy and surface quality. It had importantscientific significance and application value.