Silicon anisotropic etching in Triton-mixed and isopropyl alcohol-mixed tetramethyl ammonium hydroxide solution

• Published in: Micro & nano letters Vol. 10; no. 9; pp. 469 - 471
• Main Authors: Yao, Mingqiu, Tang, Bin, Sato, Kazuo, Su, Wei
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 01.09.2015
• Subjects: Ammonium hydroxide; Anisotropy; convex corners; Corners; elemental semiconductors; etch rate; etched surface roughness; Etching; isopropyl alcohol‐mixed tetramethyl ammonium hydroxide solution; Microstructure; microstructure fabrication; mirror‐like surface finish; Nanostructure; Silicon; silicon anisotropic etching; surface finishing; surface roughness; Triton; Triton X‐100; triton‐mixed tetramethyl ammonium hydroxide solution; etching; triton-mixed tetramethyl ammonium hydroxide solution; mirror-like surface finish; etch rate; surface roughness; elemental semiconductors; surface finishing; convex corners; microstructure fabrication; silicon; silicon anisotropic etching; Si; etched surface roughness; isopropyl alcohol-mixed tetramethyl ammonium hydroxide solution; Triton X-100
• ISSN: 1750-0443; 1750-0443
• DOI: 10.1049/mnl.2015.0104

The anisotropic silicon (Si) etching characteristics of Si (100) in 25 wt.% tetramethyl ammonium hydroxide (TMAH) solutions containing Triton X-100 and isopropyl alcohol (IPA) were studied. The etch rate, convex corners and roughness of the etched surface were investigated. In this reported work two central goals, a mirror-like surface finish and a high reduction of undercutting, have been achieved. The best etched result was obtained in 25 wt.% TMAH + 0.25%v/v Triton + 16%v/v IPA, which has minimum convex corner undercutting and a smooth etched surface (Ra = 1 nm). This study is useful for engineering applications where the fabrication of microstructures for high-quality devices should simultaneously contain smooth surfaces on a large area and less convex corner undercutting.