Interface state capture cross section measurements on vacuum annealed and radiation damaged Si:SiO₂ surfaces

The conductance technique can be used to separate two types of fast interface state differentiated by a factor of about 20 ratio in capture cross section. By comparing vacuum annealed oxides, which are dominated by Pb defects, with radiation damaged oxides, we infer that the two types are acceptor and donor states. The conductance measurements are unable to separate Pb0 and Pb1 on the (100) surface. In vacuum annealed samples, the conductance peak broadening is dominated by surface potential fluctuations, whereas radiation damaged samples have an intrinsically broadened cross section over and above that due to the potential fluctuations.