Bayer, L.; Angermann, H.; Korte, L.: Surface photovoltage measurements on Si solar cell substrates after cleaning and passivation in ozone containing solutions. In: Robert Brunner [Ed.] : Proceedings of 10th Solid State Surfaces and Interfaces (SSSI X).. Comenius University Bratislava, Slovak Republic, 2019. - ISBN 978-80-223-4606-1, p. 14-19
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This contribution reports on surface photovoltage (SPV) investigations of wet-chemical substrate treatments in hydrochloric acid (HCl) and hydrofluoric acid (HF) containing DIW-O3 solutions, which were developed in order to reduce the number of wet-chemical process steps, by combination of cleaning, oxidation and etching processes in the same bath. According to our earlier reported results, after sequences of DIW-O3 oxidation and subsequent oxide removal in diluted HF solution on H-terminated substrates values of interface states densities Dit,min < 5 ∙ 1011eV-1cm-2 could be achieved, comparable to values obtained on similar substrates by the standard RCA process followed by HF dip. it is demonstrated, that field depending SPV measurement can be used as a surface sensitive tool to investigate and optimize wet-chemical Si surface treatments with O3-containing solutions. Oxidizing treatments in DIW-O3 with HCl admixture can be utilized for passivation of substrate surfaces by well-defined wet-chemical oxide layers as utilized for tunnel oxide passivated contacts (TOPCon). Furthermore, depending on the O3, HCl and HF content H-terminated substrate surfaces can be prepared as starting point of subsequent PECVD deposition processes for high efficiency silicon Heterojunctions.