Structural and Electric Characterization of Sputtered Pt/WSe2 Contacts toward High-Performance 2D p-FETs

For high-performance p-type field-effect transistors (FETs) based on two-dimensional (2D) materials, the use of Pt as the contact metal, with its high work function, is advantageous for effective hole injection into the 2D channel. However, the high-energy sputtering process required to deposit Pt, due to its high melting point, often induces significant damage to the 2D materials. Recently, the achievement of nearly ideal van der Waals contacts in Sb₂Te₃/MoS₂ via sputtering has motivated us to investigate WSe₂ p-FETs with sputtered Pt electrodes. Notably, reasonable p-FET performance was observed even in monolayer WSe₂. However, various characterizations revealed that the crystal structure of WSe₂ was no longer preserved, suggesting the formation of a quasi-edge contact between Pt-sputtered WSe₂ and the WSe₂ channel. Moreover, from the perspective of sputtering applicability, the relationship between deposition methods, deposited materials, and the resulting extent of damage was systematically examined.