A Specific Contact Resistivity Extraction Scheme With Strong Variation Immunity Customized for Thin-Film Semiconductors: Bridge Transmission Line Method

We report a novel bridge transmission line method (TLM) for thin-film semiconductor-based specific contact resistivity extraction with validations from both simulations and experiments. Our bridge TLM (BTLM) possesses several key features, including the capability of modeling parasitic resistance, simple fabrication utilizingonly three lithography steps, highly accurate specific con-tact resistivity extraction with theoretical resolution down to 10(-11)Omega cm(2), and most importantly, strong variation immunity, which has rarely been considered in previously reported TLMs. Such immunity is enabled by its special structure design and a nonlinear fitting strategy. The theoretical resolution as well as the excellent variation immunity of BTLM have been thoroughly verified via different simulation tools, i.e., LT spice and technology computer aideddesign Sentaurus. By applying the proposed BTLM to thenickel/indium-tin-oxide (ITO) contact with 10 nm thick ITO,a record-low specific contact resistivity of 4.4x10(-8)Omega cm(2 )was obtained among all kinds of metal/oxide semiconductor (OS) contact without the assist from applied electric field.