Analytical model for accurate extraction of metal-semiconductor ohmic contact parameters using a novel electrode-pair layout scheme

Abstract In this paper, an electrode-pair model is proposed and demonstrated for the first time to accurately extract the electrical resistance parameters of the planar metal-semiconductor ohmic contacts. Different from the conventional transmission line model, the proposed model layout features a series of separated electrode pairs with the same electrode distance but various widths. Meanwhile, an equivalent circuit for contact resistance composition is set up to clearly specify the contribution of each resistance component to the overall contact performance. The semiconductor sheet resistances underneath the contact and outside the contact area are treated as completely independent variables. The proposed scheme is modeled theoretically and analyzed by the TCAD simulations, and the validity of the model is verified by the experimental data. Finally, the variance of the sheet resistance underneath the contact after annealing treatment can be distinguished by the model and hence more actual and precise specific contact resistance is achieved. This work provides a distinct perspective to understand and quantify the electrical characteristics of the semiconductor ohmic contacts, and it can also assist engineers for a better electrode layout design.