A combination process of magnetorheological finishing and computer controlled optical surfacing on single-crystal silicon surface

Abstract

The combination process of Magnetorheological finishing (MRF) and Computer controlled optical surfacing(CCOS) are adopted to overcome the drawback of traditional polishing method in final finishing of single-crystal silicon and the deterioration of the surface roughness of single-crystal silicon by Magnetorheological finishing. In order to meet the requirements of single-crystal silicon by magnetorheological finishing, a new magnetorheological finishing fluid is prepared and orthogonal process parameters experiments are designed to optimize the magnetorheological finishing parameters. Through the uniform finishing experiment of MRF and CCOS, the processing sequence conditions of the combined process are obtained. A single-crystal silicon mirror with diameter of 100 mm is finished with several iterations of MRF and CCOS, the surface roughness Ra reaches 0.7 nm which verified the prepared magnetorheological finishing fluid and the optimized parameters satisfied the Finishing requirements of the single-crystal silicon surface. The results prove that the combination of MRF and CCOS process has unique advantages in the final finishing of single-crystal silicon.