Chemisorption competition between H2O and H-2 for sites on the Si surface under Xe+ Ion bombardment : an XPS study

Agradecimentos: Part of this work was supported by FAPESP Project Nos. 2012/10127-5, 2019/24095, 2019/18460-4, 2019/00757-0, 2018/24461-0. C.A.F. and F.A. are CNPq’s fellows. This paper is part of the Ph.D. thesis of VGA realized in the IFGW, UNICAMP, Brazil. The authors are grateful to C. Piacenti for technical help Abstract: This paper reports the competition of H2O (residual) and H-2 by site (defects) on the Si surface, created by Xe+ ion bombardment. X-ray photoelectron spectroscopy (XPS) in an ultrahigh vacuum system attached to the sample preparation chamber provided the data for the analyses. As hydrogen cannot be detected by XPS, an indirect method to evaluate the O and H cover ratio was developed. The hydrogen passivation effect obtained by the formation of the Si-H bond due to H-2 chemisorption limits Si-OH and Si-O-Si bonds, which are products of H2O dissociation. In addition, the results have shown that Xe+ ion bombardment diminished the H-2 chemisorption energy barrier onto Si FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ Fechado