Silicon solar cell fabrication includes multiple wet cleaning steps involving large amounts of chemicals Most of wet-chemical processes in alkaline or acidic solutions with subsequent HF treatment, applied in high efficiency Si solar cell fabrication result in hydrophobic substrate surfaces.However, the process homogeneity of a subsequent steps depends on the wetting of the silicon surface.In order to change the surface to more hydrophilic behavior the surface oxidation of textured p-type substrates with DIW-O3 was evaluated.This paper reports investigations of electronic interface properties of Si substrates after wet-chemical oxidation in DIW-O3 and subsequent H-termination in dilyted HF(1%).The surface photovoltage technique (SPV) was utilized for non-destructive and surface-sensitive measurements of the surface charge, the density (Dit) and the energetic distribution of interface states Dit(E).Dit increases with O3 content and treatment time and saturates when the Dox exceeds 15 ppm · min at high values of Dit,min ≥ 1013 eV-1cm-2 due to the rapid oxide growth.Both on fiat p-type Si(100)and n-type Si(111) types of substrates best results were obtained using Dox 15-20 ppm· min.Comparatively lower values of Ditmin were found after RCA I and RCA Ⅱ treatments, respectively.Sequences of DIW-O3 oxidation and subsequent oxide removal in HF containing solutions can be also utilized to prepare clean hydrophobic substrates.On so prepared 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.In coclusion wet-chemical oxidation in DIW-O3 at ambient temperature could be a high quality and low cost alternative to current approaches with liquid chemicals also for the preparation of H-terminated Si substrate surfaces.