Dry etching characteristics of Si-based materials using CF4/O2 atmospheric-pressure glow discharge plasma

We etched materials used for semiconductor manufacturing processes, such as poly-Si films, SiN films, SiO2 films and photoresists, using atmospheric-pressure glow discharge plasmas, where CF4 gas was added to the O-2 gas in the discharge and downflow regions. High etching rates of 2.3 mu m/min for the poly-Si and SiN films, 1.0 mu m/min for the SiO2 films and 7.0 mu m/min for photoresist were obtained in the discharge region. Furthermore, a reasonably high etching rate of 0.82 mu m/min for poly-Si films was also confirmed in the downflow region. The etching characteristics obtained under atmospheric-pressure glow discharge plasmas and low-pressure glow discharge plasmas in the discharge region were very similar. However, in the downflow region, the etching rates of SiN and SiO2 films were substantially reduced compared to those in the discharge legion. These etching mechanisms were also modeled based on analytical data and the results of the etching evaluation.