Contact engineering of metallic Ni-integrated niobium sulfide via H2S treatment for enhanced MoS2 transistor performance and CMOS compatibility

For scaled transistors utilizing transition metal dichalcogenide (TMDC) channels, we demonstrate that the Ni0.19Nb1.16S2 is a promising contact material for n-type field-effect transistors (nFETs). This material is derived from the metallic TMDC NbS2 through Ni incorporation and enables monolayer MoS2-channel nFETs with Ni0.19Nb1.16S2 source/drain contacts to achieve higher on-state current and superior thermal stability up to 600 °C compared to devices with NbS2 or Ni contacts. Metallic NbS2, owing to its high work function, is suitable as a contact material for p-type FETs (pFETs). However, the incorporation of Ni atoms into NbS2 modifies both its crystal structure and work function, effectively converting its suitability from pFETs to nFETs applications. Therefore, Ni0.19Nb1.16S2 represents a promising contact material for MoS2-channel nFETs, while NbS2 remains appropriate for pFETs, thereby advancing CMOS integration process technology for TMDC-based CMOS devices.