Deconvoluting Contact Resistance in Monolayer MoS₂ Using Advanced Test-Structures

Abstract

Contact resistance has been a bottleneck in estimating the performance limits of 2-D-field effect transistor (FET) performance; most reports still parameterize contact performance into a single value, i.e., contact resistance ( RC) , which is inadequate to understand the physics of contact transport. Here, we deconvolute that value into two parts: the transport at the interface, characterized by the interface resistance ( RINT) , or the specific contact resistivity ( ρC) ; and the undercontact transport by the charge-transfer-dependent sheet resistivity ( RSK) . Using structures like cross-bridge kelvin resistor (CBKR), contact end (CE) along with transmission line model (TLM) method on monolayer MoS2, clear, bias dependence estimates of both resistance components could be determined. CBKR approach yields a reliable benchmark for ρC and CE approach provides a cross-check of ρC and LT. This deconvolution turns contact resistance ( RC) from a single figure of merit into a design map, indicating when very short contacts are viable and which interface steps matter most.