Simulation of directional Si etch with various neutral beam angle distributions

Summary form only given, as follows. As the size of semiconductors is reduced to nano-scale, an influence of plasma process induced damage (PPID) is increased. Etch process using neutral beam is suggested to reduce PPID. We have performed a neutral beam simulation to obtain an outstanding etching process. The neutral beam is generated from collision between ions produced by ion-gun and reflectors. Ion-gun is simulated by XOOPIC code for high ion flux and good directionality of ions. We have carried it out by the variations of ion-gun parameters such as grid voltage, grid interval and pressure. For neutral beam simulation, we have used the modified XOOPIC code at which reflection characteristics obtained by TRIM code are appended. Neutral flux, energy and angle distribution are calculated by the variations of ion-gun type and reflection conditions (angle and length of reflector). We have studied a directional etching by an influence of neutral angle distribution at the shallow trench of silicon. As anti-reflection coating is spread on sidewall, it is analyzed that sidewall etching is reduced by anti-reflection coating. Therefore, we find optimized conditions for high neutral flux and good neutral angle distribution.