Development of ion beam sputtering technology for surface smoothing of materials

Abstract

Ion beam sputtering technique, one of the surface modification techniques, is to reduce surface roughness of materials with selective detaching atoms and nano-particles from the surface by bombarding energetic ions from a few to a few tens of keV onto the materials surfaces. This technique can be applied to the surface that needs to have sub micrometer surface roughness. Ion beam machining is used for ultra-precision machining of high-melting-point and hard, brittle materials, where machining depth needs to be precisely controlled. For ultra-precision machining of a large region in ion beam sputtering processes, a high current density ion beam and a large area ion source with a uniform beam extraction unit are necessary. To achieve a high current density and a large area ion beam with a uniform profile, we tried to develop four holes extraction grid systems and solenoidal magnetic lens. We used a high current density low energy beam from 3keV to 15keV. After sputtering, the irradiated surfaces were analyzed by WYKO NT 2000, Form Talysurf series 2 and optical microscope. The surface roughness of dot patterns of mold and die for BLU decreased by about 20–100nm with 3keV ion beam.