Possible observation of Pb0 and Pb1 centers at irradiated (100)Si/SiO2 interface from electrical measurements

By the use of ac conductance measurements, we have observed two distinct defects with different capture cross sections at the x-ray irradiated (100)Si/SiO2 interface. The capture cross section for one defect is a strong function of energy, while the other one is basically independent of energy. There is a strong possibility that these two interface defects correspond to the Pb0 and Pb1 centers seen in the electron spin resonance experiments. The fact that we do not observe the same behavior on (111) samples lends support to this hypothesis.