High Aspect Ratio Silicon Nanohole Arrays via Electric-Field-Incorporated Metal-Assisted Chemical Etching

• DOI: 10.1021/acsami.5c00564
• Publication Date: 2025-04-28T18:14:19Z
• Authors: Jungwon Suh; Juho Lee; Jaehoon Kim; Minhyung Cho; Jungah Kim; Jung Min Oh; Hoon Han; Hyo San Lee; Jihun Oh
• Keywords: Isotropic etching; Aspect ratio (aeronautics); Dry etching

The implementation of through-silicon vias for high-performance semiconductor devices requires a reliable fabrication process that can achieve high aspect ratio (HAR) silicon nanoholes (Si NHs). Currently, Si NHs are primarily fabricated via plasma-based dry etching, which has technical limitations, such as necking and bowing. Metal-assisted chemical etching (MaCE) is an alternative NH method utilizes wet chemistry catalyzed by metals. However, the formation HAR challenging because unstable motion metal catalysts during MaCE. Herein, we introduce electric-field-incorporated MaCE (EMaCE) to improve anisotropic stability NHs. etch straightness gradually improved with increasing electric field intensity while rate remained nearly constant. We optimized etchant concentration time increase rate, thus, ultra-HAR (38:1) array EMaCE.