Reconfiguration of Intrinsic Depletion‐Mode Characteristics of MoS2 Field‐Effect Transistors to High‐Performance Enhancement‐Mode Operation Using an Argon Plasma‐Induced p‐Type Doping Technique

Abstract The intrinsic n‐type behavior and unavailability of the appropriate p‐type doping method for MoS 2 allows only n‐type conduction with depletion mode (D‐mode) characteristics and forbids the implementation of p‐type field‐effect transistors (FETs). The D‐mode characteristic results in a high off‐current ( I OFF ) at zero gate bias, which limits the usage of MoS 2 FETs for industry‐scale (n‐channel metal‐oxide semiconductor) NMOS/(complementary metal‐oxide semiconductor) CMOS‐logic‐based applications due to significant power dissipation. Both these issues, i.e., i) missing technique for p‐type doping and ii) D‐mode operation are addressed here through the application of argon (Ar) plasma and subsequent O 2 bath. Here, Ar plasma results in the physical removal of sulfur (S) atoms from the MoS 2 surface, introducing sulfur vacancies, and the O 2 bath results in the chemical bonding of O 2 molecules with molybdenum (Mo) atoms at the introduced S vacancy sites. This leads to the formation of shallow acceptor states near the valance band (VB) of MoS 2 , resulting in p‐type doping and enhancement mode (E‐mode) characteristics of MoS 2 FETs. Moreover, using Ar plasma results in the reduction of contact resistance ( R C ) of E‐mode MoS 2 FETs and hence facilitates achieving high‐performance top‐gated E‐mode MoS 2 FETs with I OFF (at zero gate bias) in tens of picoamperes and I ON / I OFF in seven orders.