A Metallic amorphous chalcogenide contact for a MoS 2 channel with a quasi-van der Waals gap

Abstract The high contact resistivity at metal/semiconductor interfaces in transition metal dichalcogenides, particularly MoS 2 , severely limits device performance and remains an urgent challenge. Recently, semimetal contacts have been reported to reduce contact resistivity, however, they suffer from poor thermal stability. Here, we propose metallic amorphous chalcogenide as a solution and demonstrate amorphous TiS 2 (a-TiS 2 ) as a promising electrode material. Molecular dynamics simulations using a machine learned potential reveal the spontaneous formation of a van der Waals (vdW) gap at the a-TiS 2 /MoS 2 interface. Subsequent density functional theory calculations show that the quasi-vdW interface suppresses the formation of metal-induced gap states (MIGS). The suppression of MIGS has the potential to reduce contact resistivity. In parallel, experimental characterization of sputtered a-TiS 2 thin films by X-ray diffraction confirms thermal stability up to 500 °C. The amorphous nature facilitates omnidirectional contact formation, a critical attribute for next-generation Gate-All-Around (GAA) transistors.