Cd/p-Si Schottky barrier diodes (SBDs) with and without the native oxide layer have been fabricated to determine the importance of the fact that the series resistance value is considered in calculating the interface state density distribution (ISDD) from the forward bias current-voltage (I-V) characteristics of the Cd/p-Si SBDs. The statistical analysis yielded mean values of 0.71 +/- 0.02 eV and 1.24 +/- 0.12 for the BH and ideality factor of the Cd/p-Si SBDs (15 dots) without the native oxide layer (MS), respectively, and mean values of 0.79 +/- 0.02 eV and 1.36 +/- 0.06 eV for the Cd/p-Si SBDs (28 dots) with the native oxide layer (metal-insulating layer-semiconductor (MIS)). The interface state density (Nss) distributions of the devices were calculated taking into account their series resistance values. At the same energy position near the top of the valence band, the interface state density values without taking into account the series resistance value of the devices are almost one order of magnitude larger than Nss obtained taking into account series resistance value. (c) 2006 Published by Elsevier B.V.