Kim Soo-Gang, Yang Kyung-Chae, Shin Ye-Ji, Kim Kyong-Nam, Kim Dong-Woo, Lee Jeong Yub, Kim YeonHee, Yeom Geun-Young
SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University (SKKU), Suwon, Gyeonggi-do 16419, Republic of Korea.
Nanotechnology. 2020 Apr 9;31(26):265302. doi: 10.1088/1361-6528/ab7c75. Epub 2020 Mar 4.
The etch characteristics of Si and TiO nanostructures for optical devices were investigated using pulse biased inductively coupled plasmas (ICP) with SF/CF/Ar and BCl/Ar, respectively, and the results were compared with those etched using continuous wave (CW) biased ICP. By using pulse biasing compared to CW biasing in the etching of the line/pillar nanostructures with various aspect ratios, there was a reduction of the aspect ratio dependent etching (ARDE) and therefore, uniform etch depths for nanostructures with different pattern widths, as well as the improvement of the etch profiles without any notching, were obtained not only for silicon nanostructures but also for TiO nanostructures. The investigation has determined that the improvement of etch profiles and reduced ARDE effect when using pulse biasing are related to the decreased surface charging caused by neutralization of the surface and the improved radical adsorption (or etch byproduct removal) on the etched surfaces during the pulse-off period for pulse biasing compared to CW biasing.
分别使用带有SF/CF/Ar和BCl/Ar的脉冲偏置感应耦合等离子体（ICP）研究了用于光学器件的硅和二氧化钛纳米结构的蚀刻特性，并将结果与使用连续波（CW）偏置ICP蚀刻的结果进行了比较。在蚀刻具有各种纵横比的线/柱状纳米结构时，与连续波偏置相比，通过使用脉冲偏置，纵横比依赖性蚀刻（ARDE）有所降低，因此，不仅对于硅纳米结构，而且对于二氧化钛纳米结构，都获得了不同图案宽度的纳米结构的均匀蚀刻深度，以及没有任何缺口的蚀刻轮廓的改善。研究确定，与连续波偏置相比，使用脉冲偏置时蚀刻轮廓的改善和ARDE效应的降低与表面中和导致的表面电荷减少以及脉冲偏置的脉冲关闭期间蚀刻表面上自由基吸附（或蚀刻副产物去除）的改善有关。
