We have fabricated H-terminated Pb/p-type Si Schottky contacts with and without the native oxide layer to explain the difference between their barrier height values. It has been experimentally seen that the effective barrier heights (BHs) and ideality factor of identically fabricated diodes varied from diode to diode, and that there is a linear relationship between experimentally effective BHs and ideality factors of Schottky contacts that may be attributed to lateral inhomogeneities of the BHs. The BH value for the Pb/p-Si contacts without the interfacial oxide layer (MS sample) has ranged from 0.741 to 0.765 eV, and the ideality factor n from 1.001 to 1.040. The 1311 value for the Pb/p-Si contacts with the interfacial oxide layer (MIS sample) has ranged from 0.746 to 0.779 eV, and the ideality factor n value from 1.035 to 1.124. Furthermore, the extrapolations of the linear plot of the experimental BHs versus ideality factors have given laterally homogeneous barrier height values approximately 0.757 and 0.769 eV for the MS and MIS Pb/p-Si contacts, respectively. (C) 2003 Elsevier B.V. All rights reserved.