Angermann, H.; Wolke, K.; Gottschalk, Ch.; Moldavan, A.; Roczen, M.; Fittkau, J.; Zimmer, M.; Rentsch, J.: Surface charge and interface state density on Silicon substrates after Ozone based wet-chemical oxidation and Hydrogen-termination. Solid State Phenomena 195 (2013), p. 314-317
Textured Si solar cell substrates, as well as flat Si(100) and Si(111) reference wafers were prepared in DIW-O3 at room temperature (RT) with increasing ozone dose (Dozone). The influence of both O3-content and oxidation time on the efficiency and stability of interface conditioning was investigated. Additionally, hydrophobic, H terminated Si surfaces were prepared by the subsequent removal of the wet-chemical oxides by applying HF 1% solution. Correlations were established between morphological structure of the silicon sur¬face and DIW-O3 preparation conditions, and the resulting surface charge, density and energetic distribu-tion of rechargeable states Dit(E). The results of these investigations were correlated to previously reported findings obtained on RCA treated interface and atomically flat, H-terminated Si(111) sur-faces which were prepared by different wet-chemical oxidation and oxide removal processes. On H-terminated substrate prepared this way H terminated substrates low values of Dit(E) could be achieved, comparable to values obtained on similar substrates by the RCA process followed by HF dip. On the oxidized hydrophilic surface a homogenous oxide layer can be applied to improve the wettability for subsequent processes on textured solar substrates.