A Simplified Method for (Circular) Transmission Line Model Simulation and Ultralow Contact Resistivity Extraction

Abstract

The metal resistance in the transmission line model (TLM) structures creates a serious obstacle to determine precisely the intrinsic contact resistivity. To tackle this problem, we propose a new model, the lump model, to evaluate the metal resistance influence in both TLM and circular TLM (CTLM) test structures. In this letter, we demonstrate the high simplicity, great robustness, and flexibility of the lump model. The previous reported contact resistivity values extracted with CTLM are usually above 1 χ 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-7</sup> Ω · cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> because the metal resistance impact is commonly neglected. This is the first time that the role of the metal in CTLM is appropriately analyzed. Low contact resistivity, 3.6χ10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-8</sup> Ω · cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , of standard NiSi/n-Si contact has been extracted and this shows the high sensitivity of this method.