Diverse Texturing Characteristics Through Metal-Assisted Plasma Etching with Silver Nanowires

Abstract

The process of texturing silicon surfaces is critical for enhancing the performance of complementary metal-oxide-semiconductor image sensors that utilize silicon-based photodetectors. Traditional wet etching methods using strong acids or alkaline solutions have been commonly used but present challenges in precision, particularly for microscopic devices. As a viable alternative, dry etching processes using patterned metals and plasma are being explored. However, extensive studies across various metals are necessary. This study introduces a silicon nanotexturing process using silver nanowires and Cl2-based plasma. The etching mechanism involves accelerated etching through eddy currents and hole injection coupled with a diffusion phenomenon of silver. In this study, we examined variations in the etching profile with respect to etching time, upper and bottom radio-frequency powers, and process pressure. Additionally, we analyzed the effects of ion bombardment, enhanced by the introduction of Ar gas. The findings are expected to significantly contribute to the improvement of micro-optoelectronic devices.