Planarization of brittle materials by laser assisted machining

Hard and brittle materials, such as wide-gap semiconductor materials, are difficult to obtain smooth surface by machining. Micro laser assisted machining (micro-LAM) was developed to achieve both smooth and high-speed machining of the hard and brittle materials, which a thermal assisted machining method by a laser irradiation. A purpose of this study is to investigate basic thermal characteristics of the micro-LAM toward high-speed face turning of hard brittle materials. A scratch test with the micro-LAM is applied to a well-known silicon substrate in this study. A relationship between temperature and critical cutting depth (d_c) reveals thermal softening effect by micro-LAM and reduction of the crystal orientation dependence of d_c. These results suggest that micro-LAM can achieve high efficiency planarization of hard and brittle materials.