Malguth, E.; Gref, O.; Schöpke, A.; Stegemann, B.; Schmidt, M.; Angermann, H.: The influence of substrate pre-treatment on the electronic properties of the Si/SiO2 interface of ultra-thin plasma-oxides. In: 7th solid state surfaces and interfaces (7th SSSI), November 22-25, 2010, Smolenice Castle, Slovak Republic, 2010, p. 49-50
Abstract:
The successful application of silicon oxide (Si/SiO2) interfaces for nanostructures in third generation photovoltaics necessitates ultra-thin SiO2 films with low interface state densities Dit. As it is well known from investigations of MOS devices, on thermally prepared Si/SiO2 interfaces, interfacial defects give rise to interface electronic charges such as interface-trapped charges and fixed oxide charge. Therefore, alternative wet-chemical preparation methods are required to achieve contamination-free, atomically smooth Si substrate surfaces as starting point for deposition of ultra-thin oxides. We prepared ultrathin SiO2 layers with a thickness in the range of 9 ¿ 20 Å, by means of plasma oxidation utilizing thermalized atomic oxygen under ultrahigh vacuum conditions. The effects of wet-chemical pre-treatment, layer deposition and annealing processes on the electronic properties of the Si/SiO2 interface were investigated by surface photovoltage (SPV) measurements.