Transistors on two-dimensional semiconductors: contact resistance limited by the contact edges

摘要

We report for the first time a TCAD investigation on the spatial distribution of carrier injection at MoS2 contacts. The proposed semi-classical approach successfully captures the experimentally observed contact behavior. Using the model, we identify that for monolayer and bilayer MoS2, the carriers are injected at the edge of the contact metal, resulting in a high contact resistance. The primary cause of this high resistance is carrier depletion under the contacts, which is not alleviated at degenerate doping under the contacts.