Contactless electrical characterization of surface and interface of SOI materials

Electronic properties of the surface as well as the interface of silicon-on-insulator (SOI) materials have been characterized by the Kelvin method combined with surface photovoltage (SPV) measurements. In order to separate the interface properties from the surface ones, we used the data for the bulk Si surface, which was treated in the same manner, i.e. dipping in a diluted HF solution, as for the SOI surface. From the temperature dependence of the SPV for the bulk Si, the values of the built-in potential, the surface state density and the surface recombination velocity were determined to be about 0.60 eV, 6×1011 cm−2 and 6×103 cm/s, respectively, for the HF-treated Si surface. By taking these values into account, we analyzed the SPV data for separation by implanted oxygen (SIMOX) wafer. The values of the interface state density and the interface recombination velocity at the buried-oxide/SIMOX interface were estimated to be about 3×1012 cm−2 and 3×104 cm/s, respectively.