Improvement of Contact Resistance and 3D Integration of 2D Material Field‐Effect Transistors Using Semi‐Metallic PtSe<sub>2</sub> Contacts
Jae Eun Seo, Minseung Gyeon, Jisoo Seok, Sukhyeong Youn, Tanmoy Das, Seongdae Kwon, Tae Soo Kim, Dae Kyu Lee, Joon Young Kwak, Kibum Kang, Jiwon Chang
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.