Pattern dependent plasma charging effect in high aspect ratio 3D NAND architecture

Pattern dependent charging effect is explored in this study. Due to increased film thickness in 3D NAND structure, a derivative problem-the plasma-induced charging damage is enhanced during high aspect ratio (HAR) etching. In this paper, several effective methods are demonstrated to alleviate the impact of profile distortion due to charging effect while etching high aspect ratio (>14) trenches.