Using a two-contact circular test structure to determine the specific contact resistivity of contacts to bulk semiconductors

We present a numerical method to extract specific contact resistivity (SCR) for three-dimensional (3-D) contact structures using a two-electrode test structure. This method was developed using Finite Element Modeling (FEM). Experimental measurements were performed for contacts of 200 nm nickel (Ni) to p+-type germanium (Ge) substrates and 200 nm of Titanium (Ti) on 4H-Silicon Carbide (SiC). The SCR obtained was (2.3-27)?10-6 ??cm2 for the Ni-Ge contacts and (1.3-2.4)?10-3 ??cm2 for the Ti-SiC.