COMPARISON OF DRY DEVELOPMENT TECHNIQUES USING O-2 AND SO2 O-2 LOW-PRESSURE PLASMAS/

A parametric study of the pattern transfer step in a trilevel resist s ystem using oxygen-based plasmas has been performed using a distribute d electron cyclotron resonance reactor with independent rf biasing. In pure oxygen plasmas, critical dimension loss is always present. The m echanisms most likely to be responsible for these defects during the p attern transfer process are presented and discussed. A novel plasma et ching process based on sidewall passivation by sulfur is proposed usin g SO2/O2 mixtures. Perfect anisotropy with negligiable critical dimens ion loss is obtained at room temperature.