A hybrid CO(2) laser processing for silicon etching

A novel approach to silicon (Si) etching has been demonstrated using glass assisted CO(2) laser processing. Conventional Si etching can be performed by wet etching, dry etching, Nd:YAG or UV lasers. No CO(2) laser was used to etch Si due to the absorption problem. We have etched Si with the assistance of glass beneath the Si. This approach changes light absorption behavior of Si and makes Si be etched from the top surface toward the interface. The new mechanism was discussed in viewpoint of the variation of electronic band structure, surface oxidation and light absorption of Si at high temperature.