The ultrafast laser polishing technology is a new surface processing technology in recent years. Because this technology has the characteristics of the polishing quality and less heat effect, it is very suitable for high precision polishing for hard brittle materials. This paper from the ultrafast laser polishing system structures, experimental design, and data analysis, etc., studies the ultrafast laser polishing principle and processing technology of single crystal silicon. In the experiment, the system with femtosecond laser (λ=515nm, f=4kHz) and picosecond laser (λ=532nm, f=200kHz) polishing materials, after processing, system using digital microscope and surface profiler tests the surface roughness and surface morphology of the region. This paper analyzes the laser energy density, the spot overlap and scanning mode for ultrafast laser polishing quality. The orthogonal experiment design can be clearly analyzes the importance of factors are in polishing effect. And the single factor experiment design can be clearly analyzes the parameter level changes on the polishing effect. Combining with two methods of experiment, parameters can be optimized scientifically and comprehensively.
Laser polishing technique using thermal effect of the interaction of light with matter to achieve removal of material, it is a non contact polishing techniques. In recent years, ultra fast laser polishing techniques got great progress, when ultra fast laser matter interaction, no thermal effect or thermal effect is very small, the removal of material is achieved primarily through momentum transfer. In the material removal process will appear the phenomenon of surface atoms in the redistribution, using this effect, we are likely to achieve the manufacture of the ultra smooth surface of atomic scale magnitude. This article has discussed and analyzed the mechanism of ultra fast laser semiconductor materials, based on this, parameters and their influence on the influence of ultra fast laser polished monocrystalline silicon effects were studied. Used the orthogonal experiment method to optimize the main parameters of the laser polishing, it can reach to a better combination of optimized parameter values. Used self-built picosecond laser polishing system and did monocrystalline silicon polishing experiment, got a good polishing effect.