Saturday, October 27, 2018

Area-selective ALD using Si precursors as inhibitors

Area-Selective Atomic Layer Deposition Using Si Precursors as Inhibitors

Rizwan Khan, Bonggeun Shong, Byeong Guk Ko, Jae Kwang Lee, Hyunsoo Lee, Jeong Young Park, Il-Kwon Oh, Shimeles Shumi Raya, Hyun Min Hong, Kwun-Bum Chung, Erik J. Luber, Yoon-Seok Kim, Chul-Ho Lee, Woo-Hee Kim, and Han-Bo-Ram Lee

Chem. Mater., Article ASAP
DOI: 10.1021/acs.chemmater.8b02774

Short-chain aminosilanes, namely, bis(N,N-dimethylamino)dimethylsilane (DMADMS) and (N,N-dimethylamino)trimethylsilane (DMATMS), have been used as Si precursors for atomic layer deposition (ALD) of SiO2. In this work, the DMADMS and DMATMS Si precursors are utilized as inhibitors for area-selective ALD (AS-ALD). The inhibitors selectively adsorb on a SiO2 surface but not on H–Si, so that SiO2 becomes selectively deactivated toward subsequent ALD. The deactivation of the SiO2 surface by the inhibitors was investigated using various experimental and theoretical methods, including surface potential measurements, spectroscopic ellipsometry, and X-ray photoelectron spectroscopy. Better inhibition was observed for ALD of Ru and Pt than for ALD of Al2O3 and HfO2. Through quantum mechanical and stochastic simulations, the difference in the blocking ability for noble metal and metal oxide ALD by the aminosilane inhibitors could be attributed to the inherently partial surface coverage by the inhibitors at their saturation and the reactivity of the subsequent ALD precursors. As silane inhibitors can be easily integrated with vacuum-based processes to facilitate high volume manufacturing of upcoming electronic devices, the current study provides a potential approach for the utilization of AS-ALD in pattern fabrication inside 3D nanostructures.
"Reprinted with permission from (DOI: 10.1021/acs.chemmater.8b02774). Copyright (2018) American Chemical Society."