The dependence of I-V and C-V characteristics on temperature in the H-terminated Pb/p-Si(1Â 0Â 0) Schottky barrier diodes

The current-voltage (I-V) and capacitance-voltage (C-V) characteristics of H-terminated Pb/p-Si/Al contacts fabricated by us have been measured in the temperature range of 77-300 K. The experimental values of the barrier height (BH) Φbo and the ideality factor n for the device range from 0.674 and 1.072 eV (at 300 K) to 0.352 and 2.452 eV (at 77 K), respectively. The ideality factors become larger with lowering temperature while the barrier height decreases. The Φbo(n) plot shows a linear dependence in the temperature range of 77-300 K that can be explained by the barrier inhomogeneity at the metal/semiconductor interface. The extrapolation of the linear Φbo(n) plot to n = 1 has given a homogeneous barrier height of approximately 0.713 eV for the Pb/p-Si(1 0 0) contact. A Φbo versus 1/T plot was drawn to obtain evidence of a Gaussian distribution of the BHs, and values of Φ¯bo=0.819eV and σs = 80.5 mV for the mean BH and zero-bias standard deviation have been obtained from this plot, respectively. Then, a modified ln(I0/T2)−q2σs2/2k2T2 versus 1/T plot gives Φ¯bo and A* as 0.828 eV and 54.89 A/cm2 K2, respectively. Furthermore, an average value of −0.687 meV/K for the temperature coefficient has been obtained, the value of −0.687 meV/K for hydrogen terminated p-type Si differs from those given for p-type Si without hydrogen termination in the literature.