Energy state distributions of the Pb centers at the (100), (110), and (111) Si /SiO2 interfaces investigated by Laplace deep level transient spectroscopy

The energy distribution of the P_b centers at the Si /SiO₂ interface has been determined using isothermal laplace deep level transient spectroscopy. For the (111) and (110) interface orientations, the distributions are similar and centered at 0.38eV below the silicon conduction band. This is consistent with only P_b0 states being present. For the (100) orientation, two types of the interface states are observed: one similar to the (111) and (110) orientations while the other has a negative-U character in which the emission rate versus surface potential dependence is qualitatively different from that observed for P_b0 and is presumed to be P_b1.