New development of ultra-smooth surface machining technology

The overview is presented for the progress of ultra-smooth surface machining technologies, and some typical methods and principles are introduced. Moreover, an atmospheric pressure plasma polishing (APPP) method is developed. APPP utilizes a capacitance coupling atmospheric pressure radio-frequency plasma torch to generate plasma and reactive radicals. It accomplishes the atom scale removal process by chemical reactions with no surface/subsurface defects introduced. The experiment results indicate that, in initial operations applied on silicon wafers, the 1 μm/min removal rate in depth and Ra 0.6 nm surface roughness have been achieved.