Research On Nano-processing Performance Of Silicon

Semiconductor silicon plays an important role in national development and civil commercial, and the ultra precision machining technology of silicon has an important strategic significance. It will provide a broader space for development of silicon wafer processing after exploring on the properties of silicon’s nano-machining. In nano-machining process, the scale is at the atomic level, which has larger difference from traditional processing. Molecular dynamics is based on the simulation of interaction among atoms, and it is an effective method for nano-scale materials processing research, which has an accurate result. Nano-indentation and nano-scratches are accurate material performance testing experiment method to study on the material. In this study, MD method is used to research on the silicon, combined with nano-indentation and naon-scratches. It contains:Based on GPU technology, we have built a large-scale MD simulation platform, which can be used to calculate above10millions atoms, and the speed is about two times of the CPU platform. Several experience potentials are used to construct multi-component alloy’s inter-atomic potential.Silicon’s MD nano-indentation and nano-scratches models are built and load-displacement curve is drawn and used to calculate the nano-hardness of silicon during the nano-indentation, and the nano-hardness is between9.0Gpa and11.0Gpa. The temperature, force and energy are studied during the nano-scratches. Otherwise, material deformation and material removal mechanism of silicon are explained, and coordination analysis is introduced to analyze the formation of damage layer. Also, different parameters are compared to get more about the effects of silicon processing.Defect structure of silicon is established based on ideal structure of silicon and the accuracy of the model is verified based on first principles and theoretical study of lattice dislocations, and the errors are less than five percent. Vacancy defect model and stacking fault model are studied during the MD simulations, and the results show that the existence of defect structure will reduce the nano-hardness of materials, and silicon with defects will not suit for ultra-precision machining.Silicon (100) plane is used for the nano-indentation and nano-scratches experiment. After drawing the load-displacement curve, the nano-hardness of "size effect" is found and analyzed. Through the friction coefficient curve, plastic removal and brittleness removal are explained. Besides, the formation of damage layer is analyzed by scanning the surface of indentation and scratches. The results are consistent with those of MD simulations.