Share Email Print
cover

Proceedings Paper

Fabrication of high aspect ratio silicon gratings by interference lithography and potassium hydroxide anisotropic etch technique
Author(s): Yanchang Zheng; Keqiang Qiu; Xiaolong Jiang; Qingbo Wang; Lixiang Wu; Lali Bi; Yilin Hong
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

The authors report a new process combining interference lithography with potassium hydroxide (KOH) anisotropic etch technique for fabrication of high aspect ratio silicon gratings on (110) oriented silicon wafers. This new process has the ability in fabricating high aspect ratio silicon gratings with extremely smooth sidewalls over a large sample area. An alignment method was developed to align interference fringes to the vertical (111) planes of (110) oriented wafers. In addition, a room temperature etch process with 50 wt % KOH solution was chosen to finally get an etch anisotropy of 188. Better etch uniformity was achieved by adding a surfactant to the aqueous KOH to promote the release of hydrogen bubbles. To increase latitude in KOH etching process, deposition of aluminum under a sloped angle with respect to the grating structures was utilized to obtain a high duty cycle nitride mask. To prevent the collapse of high aspect ratio grating structures caused by surface tension, a liquid carbon dioxide supercritical point dryer was used in the drying process. The authors successfully fabricated 320nm period gratings with aspect ratio up to 100 on 5-μm-thick silicon membranes on (110) oriented silicon-on-insulator wafers. The sample area is about 50 mm × 60 mm. The roughness (root mean square) of the sidewall is about 0.267 nm.

Paper Details

Date Published: 28 August 2014
PDF: 8 pages
Proc. SPIE 9170, Nanoengineering: Fabrication, Properties, Optics, and Devices XI, 917018 (28 August 2014); doi: 10.1117/12.2058669
Show Author Affiliations
Yanchang Zheng, Univ. of Science and Technology of China (China)
Keqiang Qiu, Univ. of Science and Technology of China (China)
Xiaolong Jiang, Univ. of Science and Technology of China (China)
Qingbo Wang, Univ. of Science and Technology of China (China)
Lixiang Wu, Univ. of Science and Technology of China (China)
Lali Bi, Univ. of Science and Technology of China (China)
Yilin Hong, Univ. of Science and Technology of China (China)


Published in SPIE Proceedings Vol. 9170:
Nanoengineering: Fabrication, Properties, Optics, and Devices XI
Eva M. Campo; Elizabeth A. Dobisz; Louay A. Eldada, Editor(s)

© SPIE. Terms of Use
Back to Top