New gas chemistries for high-performance and chargeless dielectric etching

This paper proposes a new radical control (selective radical generation) method for high-performance SiO2 patterning using non-perfluorocarbon gases (CF3I and C2F4) in ultrahigh frequency (UHF) plasma. This method enables independent control of polymerization and etching through the selective generation of CF2 and CF3 radicals in CF3I/C2F4 gas mixture plasma. Thus it could accomplish both a high etching rate and high etching selectivity during SiO2 contact hole formation. The gas chemistries could also suppress charge-up damage during SiO2 contact hole formation because a low-electron temperature is maintained while realizing high CF2 radical flux and ion flux in the plasma. (C) 1999 Elsevier Science Ltd. All rights reserved.