Electrical characterization of gold contact on porous silicon layers

Abstract

Investigation on metallic contact on porous silicon (PS) layers is typically important before final integration into application devices. The electrical characterization of Au thickness of 100 nm and ∼210 nm on ∼3 μm and ∼6 μm PS thickness on PS were studied by measuring the current-voltage (I-V) response. The PS layers of n-type oriented silicon (Si) wafer were prepared by electrochemical etching. Au was deposited on the PS layers using Q150RS automated sputter coater. Based on scanning electron microscope (SEM) images, the thickness of PS was confirmed as 3.07 μm and 6.15 μm for respective samples. The average pore diameter was determined with the aid of ImageJ and Matlab by applying image processing analysis. There were found to be 17.91 μm and 27.26 μm respectively. The I-V curve of PS with Au contact showed significant tendency of Ohmic behaviour compared to non-PS samples that shows Schottky behaviour. The higher conductivity was obtained from sample 3.07 μm of PS thickness with 100 nm Au. Based on this analysis, it can be concluded that thickness of Au and thickness of PS affect the performance of Au-PS device as the conductivity increases as the thickness of Au on PS layers was decreased.