Investigation of nano patches distribution and their effects on the current transport properties of Ni/n-Si schottky diode

The morphology of the nickel surface deposited on silicon substrate was studied using Scanning Probe Microscopy (SPM). The results showed that the surface of nickel was consisted of nanopatches with the dimension range of 20 to 40 nm. The current transport mechanism through the patches was investigated at different applied bias voltages. It was revealed that by applying lower forward bias voltage, the current initially passed through the patches with smaller potential barrier height and then through middle barrier height. Finally, by increasing the voltage current, the current passed through over all the patches. The effect of potential barrier Ni/n-Si Schottky diodes with 350 m radius is attributed to the interaction between the patches at free surface and adjacent boundaries with metal-semiconductor contact and the potential difference between metal surface and semiconductor surface. The current transport mechanism through the patches was also studied under reverse bias condition. By studding the I-V characteristics of Schottky contact, it was concluded that current transport mechanism was depended on the distribution of the patches and their sizes. Moreover, the results obtained from these studies were co-related with that of the theoretical model. Copyright © 2012 American Scientific Publishers. All rights reserved.