Reactive ion stream etching utilizing electron cyclotron resonance plasma

Reactive ion stream etching has been developed for highly accurate etching with little bombardment induced damage by utilizing an electron cyclotron resonance (ECR) plasma. The ion energy during etching is controlled by utilizing the interaction between the ECR plasma and a divergent magnetic field, in a low energy range from 20 to 50 eV at low gas pressures of 10-2 Pa. Highly accurate submicron patterns of polysilicon and molybdenum were obtained with high selectivities to SiO2, larger than 30, by using Cl2 gas as the main etching gas