Open AccessAlignment method combining interference lithography with anisotropic wet etch technique for fabrication of high aspect ratio silicon gratings
Author(s) -
Yanchang Zheng,
Keqiang Qiu,
Huoyao Chen,
Yong Chen,
Zhengkun Liu,
Ying Li,
Xiangdong Xu,
Hong Ye
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.023592
Subject(s) - interference lithography , materials science , optics , lithography , wafer , fabrication , silicon , aspect ratio (aeronautics) , interference (communication) , x ray lithography , root mean square , grating , surface finish , optoelectronics , resist , nanotechnology , medicine , channel (broadcasting) , physics , alternative medicine , pathology , layer (electronics) , composite material , electrical engineering , engineering
A method was developed for aligning interference fringes generated in interference lithography to the vertical {111} planes of <110> oriented silicon wafers. The alignment error is 0.036°. This high precision method makes it possible to combine interference lithography with anisotropic wet etch technique for the fabrication of high aspect ratio silicon gratings with extremely smooth sidewalls over a large sample area. With this alignment method, 320 nm and 2 μm period silicon gratings have been successfully fabricated. The highest aspect ratio is up to 100. The sample area is about 50 mm × 60 mm. The roughness (root mean square) of the sidewall is about 0.267 nm.