The generation mechanism and suppression method of the "comet tail" defect on the single-crystal silicon surface polishing with magnetorheological

Abstract

Single-crystal silicon is an important material in the high precision reflector, and its processing quality directly affects the overall performance index of the reflector. Aiming at the problem of “comet tail” defect produced by the magnetorheological machining process, the process parameters are controlled by the combination of experiments and simulations, and the surface roughness changes after different scanning speeds under the same removal depth are compared and analyzed. The results show that under the same process parameters, the probability of “comet tail” defects are related to density and surface quality. The main factors affecting the occurrence probability and density of “comet tail” defects are process parameters. In actual processing, it is necessary to establish a threshold of process parameters, so that the “Comet tail” defect is less within the threshold and can be quickly removed. The final threshold range is: buffing wheel speed< 220rpm, flow rate< 80L/min, depth coefficient< 0.25, magnetic field strength< 7A. By discussing the “Comet tail” defect suppression method and key technology, it provides technical support for the realization of high precision control manufacturing of single-crystal silicon.