Abstarct: Today, the Schottky diodes baxsed on mextal–semiconductor (MS) and mextal–insulator–semiconductor (MIS) structures have found a wide variety of applications in electronics and optoelectronics devices. In this experimental study, we have attempted to build three Schottky barrier diodes: Al/p-Si, Cu/p-Si and Al/ porouse silicon (PS)/p-Si structures. The temperature dependent of the forward bias current-voltage (I-V) characteristic of these samples were measured in the range of 300-368 K. The data were then processed on the baxse of the thermionic emission theory, quantitatively. Through this analysis we have considered the role of various parameters including: barrier height, ideality factor, series resistance and the interface density of states, while considering the presence of the native oxide laxyer at the mextal-Si interface. The data analysis in flat interface samples show in order to obtain a reasonable result for the variation of effective parameters like the barrier heigh and the Richardson coefficient. We need to use the generalized thermionic emission theory considering a finite Gaussian distribution for the barrier height at the interface. The experimental data in porous samples (with different anodizing current densities) show a reduction in the passing current compared with the non-porous device. The reason for this behavior could be due to bigger (2 to 3 times) ideality factor in these samples compare with the flat one that in turn lead to a higher surface state density as a result at the higher prosity and higher area at the interface.