Numerical simulation and primary validation of ion-filtering capability of a dual grid installed in inductively coupled plasma

As semiconductor technology nodes continue to scale, radical etching—free from charge-induced damage—has become essential for achieving atomic-level precision, high selectivity, and ultra-low damage in nanostructure fabrication. However, the damaging ions that coexist in low-temperature plasma sources must be effectively filtered, and the simplest single-grid filter no longer meets the stringent requirements of advanced manufacturing. To address this issue, this paper proposes a dual-grid configuration targeted at enhancing ion-filtering efficiency without significantly increasing system complexity. A two-dimensional simulation model was established to systematically investigate the influence of key parameters (e.g. grid spacing and aperture size) on ion-filtering efficiency and to identify the optimal dual-grid configuration. Experimental validation confirms that the optimally designed dual grid achieves an ion-filtering efficiency of up to 99.999%, a value that significantly surpasses previously reported results.