Radical, ion, and photon's effects on defect generation at SiO2/Si interface during plasma etching

Defect generation and recovery at the SiO2/Si 2 /Si interface are experimentally studied during SiO2 2 etching and annealing. The SiO2 2 etching over the underlaying Si is performed with CF4 4 plasma, where the remaining SiO2 layer thickness is varied to clarify the effects of radicals, ions, and photons on the defect generation. The defects are generated initially by photon irradiation, and then generated by ion bombardment/penetration, the remaining layer becomes thin. Around the endpoint, defects are also generated by radical reactions and in diffusion. The photon-mediated defects are fully recovered by annealing, whereas the ion and radical-mediated defects are not sufficiently recovered; residual defects are created.