High-Performance Monolayer WSe2 p/n FETs via Antimony-Platinum Modulated Contact Technology towards 2D CMOS Electronics

Low resistance contact technology for 2D semiconductors is a key bottleneck for the practical application of 2D channel materials at advanced logic nodes. This work presents a novel Sb-Pt modulated contact technology which can alleviate the Fermi-level pinning effect and mediate the band alignment at the metal-2D semiconductor interface, leading to exceptional ohmic contacts for both p-type and n-type WSe 2 FETs (p/n FET). WSe 2 FETs with different Sb/Pt contact compositions, in combination with new oxide-based encapsulation/doping technologies, exhibits record low pFET contact resistance of $0.75 \mathrm{k}\Omega \bullet \mu \mathrm{m}$ among all reported monolayer (1L) 2D pFETs. The nFET contact resistance of $1.8 \mathrm{k}\Omega \bullet \mu \mathrm{m}$ is also the lowest among 1L WSe 2 nFETs. Both 1L WSe 2 pFET and nFET demonstrated remarkable on-state p/n current $\sim 150 \mu \mathrm{A}/ \mu \mathrm{m}$ at $\vert \mathrm{V}_{D} \vert =1\mathrm{V}$, indicating the potential of WSe 2 for CMOS applications. A new version of the semi-automated dry transfer process for chemical vapor deposition (CVD) WSe 2 was also developed utilizing a novel Bi/PMMA/TRT support stack, offering low defect wrinkle-free WSe 2 transfer at wafer-scale.