Demonstration of PdSe2 CMOS Using Same Metal Contact in PdSe2 n-/p-MOSFETs through Thickness-Dependent Phase Transition

Abstract

In this study, PdSe2 n- and p-metal-oxide semiconductor field-effect transistors (MOSFETs) are realized using the same conventional metal contact without any doping processes through utilizing the thickness-dependent phase transition in PdSe2. PdSe2 is semiconducting with a sizable band gap in a few layers while semimetallic in bulk. With the thin semiconducting PdSe2 for the channel and the conventional metal source/drain, an n-type behavior is achieved, whereas a p-type behavior with the thin PdSe2 channel and the thick semimetallic PdSe2 source/drain. To understand the carrier injection at the interface between the thin PdSe2 channel and the thick PdSe2 source/drain, a rigorous analysis of the band alignment and the temperature-dependent transfer characteristics is presented to extract the Schottky barrier height at the interface. Additionally, interconnecting PdSe2 n- and p-MOSFETs successfully demonstrate complementary metal-oxide semiconductor (CMOS) inverter with clear voltage transfer characteristics. The proposed approach to control the polarity of PdSe2 MOSFETs using the unique thickness-dependent phase transition in PdSe2 is promising for realizing the CMOS logic circuit with the same channel material and single contact metal.