Photohyphen;assisted anisotropic etching of phosphorushyphen;doped polycrystalline silicon employing reactive species generated by a microwave discharge

摘要

An anisotropic etching of heavily phosphorushyphen;doped polycrystalline silicon is achieved by protecting the etched sidewall with polymerized film which results from the reaction of chlorine species and methyl methacrylate. Chlorine species are generated by a microwave discharge in Cl2in the portion separated from a reaction chamber with a laser beam irradiation system. The laser beam enhances the removal of the polymerized film on the illuminated surface except the sidewall. And the Si/SiO2etch rate ratio is infinite in this system.