標題: A computational study on the adsorption configurations and reactions of SiHx(x=1-4) on clean and H-covered Si(100) surfaces
作者: Le, Thong N-M
Raghunath, P.
Huynh, Lam K.
Lin, M. C.
應用化學系
Department of Applied Chemistry
關鍵字: Silane precursor;Silicon surfaces;Si(100);Hydrogen abstractions;Plasma enhanced
公開日期: 30-十一月-2016
摘要: Possible adsorption configurations of H and SiHx (x= 1 4) on clean and H-covered Si(100) surfaces are determined by using spin-polarized DFT calculations. The results show that, on the clean surface, the gas-phase hydrogen atom and SiH3 radicals effectively adsorb on the top sites, while SiH and SiH2 prefer the bridge sites of the first layer. Another possibility for SiH is to reside on the hollow sites with a triple-bond configuration. For a partially H-coverd Si(100) surface, the mechanism is similar but with higher adsorption energies in most cases. This suggests that the surface species become more stable in the presence of surface hydrogens. The minimum energy paths for the adsorption/migration and reactions of H/SiHx species on the surfaces are explored using the climbing image-nudged elastic band method. The competitive surface processes for Si thin-film formation from SiHx precursors are also predicted. The study reveals that the migration of hydrogen adatom is unimportant with respect to leaving open surface sites because of its high barriers (>29.0 kcal/mol). Alternatively, the abstraction of hydrogen adatoms by H/SiHx radicals is more favorable. Moreover, the removal of hydrogen atoms from adsorbed SiHx, an essential step for forming Si layers, is dominated by abstraction rather than the decomposition processes. (C) 2016 Elsevier B.V. All rights reserved.
URI: http://dx.doi.org/10.1016/j.apsusc.2016.06.099
http://hdl.handle.net/11536/132601
ISSN: 0169-4332
DOI: 10.1016/j.apsusc.2016.06.099
期刊: APPLIED SURFACE SCIENCE
Volume: 387
起始頁: 546
結束頁: 556
顯示於類別:期刊論文