Controlling the Polarity of WSe₂ FETs by Interface Engineering for High-Gain CMOS

Controlled polarity regulation is one of the key obstacles to the practical application of two-dimensional semiconductor field-effect transistors (FETs). Herein, n- and p-channel WSe2-based FETs were fabricated through interface engineering. The n- and p-channel WSe2 FETs were obtained via metal-oxide and CuInS2 passivation, respectively. The performance of WSe2 FETs did not degenerate during the doping process owing to the concept of damage-free integration. Hence, the field-effect mobility could exceed 20 and 64 cm2 V–1 s–1 in n- and p-channel devices, respectively. Moreover, the polarity of WSe2 FETs was continuously regulated through fine control of the thickness of the oxide layer and Cu content. Thus, n- and p-type WSe2 FETs with excellent output matching were demonstrated, and complementary metal-oxide semiconductor inverters were fabricated. The complementary metal-oxide semiconductor inverter showed an ultrahigh voltage gain beyond 175 and a total noise margin of ∼85%, indicating an ultrahigh logic state transition speed and excellent anti-interference ability. Our results provided a damage-free and continuous method to adjust the polarity of WSe2 FETs and support its practical application in next-generation integrated circuits.