Improvement of Contact Resistance and 3D Integration of 2D Material Field‐Effect Transistors Using Semi‐Metallic PtSe₂ Contacts

Abstract

Abstract In this work, the potential of 2D semi‐metallic PtSe 2 as source/drain (S/D) contacts for 2D material field‐effect‐transistors (FETs) through theoretical and experimental investigations, is explored. From the density functional theory (DFT) calculations, semi‐metallic PtSe 2 can inject electrons and holes into MoS 2 and WSe 2 , respectively, indicating the feasibility of PtSe 2 contacts for both n‐ and p‐metal‐oxide‐semiconductor FETs (n‐/p‐MOSFETs). Indeed, experimentally fabricated flake‐level MoS 2 n‐MOSFETs and WSe 2 p‐MOSFETs exhibit a significant reduction in contact resistance with semi‐metallic PtSe 2 contacts compared to conventional Ti/Au contacts. To demonstrate the applicability for large‐area electronics, MoS 2 n‐MOSFETs are fabricated with semi‐metallic PtSe 2 contacts using chemical vapor deposition‐grown MoS 2 and PtSe 2 films. These devices exhibit outstanding performance metrics, including high on‐state current (≈10 −7 A/µm) and large on/off ratio (>10 7 ). Furthermore, by employing these high‐performance MoS 2 n‐MOSFETs, vertically stacked n‐MOS inverters are successfully demonstrated, suggesting that 3D integration of 2D material FETs is possible using semi‐metallic PtSe 2 contacts.