Large-Scale Complementary Logic Circuit Enabled by Al 2 O 3 Passivation-Induced Carrier Polarity Modulation in Tungsten Diselenide.
Tanmoy DasSukhyeong YounJae Eun SeoEunyeong YangJiwon ChangPublished in: ACS applied materials & interfaces (2023)
Achieving effective polarity control of n- and p-type transistors based on two-dimensional (2D) materials is a critical challenge in the process of integrating transition metal dichalcogenides (TMDC) into complementary metal-oxide semiconductor (CMOS) logic circuits. Herein, we utilized a proficient and nondestructive method of electron-charge transfer to achieve a complete carrier polarity conversion from p-to n-type by depositing a thin layer of aluminum oxide (Al 2 O 3 ) onto tungsten diselenide (WSe 2 ). By utilizing the Al 2 O 3 passivation layer, we observed precisely tuned n-type behavior in contrast to transistors fabricated on the as-grown WSe 2 film without any passivation layer, which display prominent p-type behavior. The polarity-transformed n-type WSe 2 transistor from the pristine p-type shows the maximum ON current of ∼0.1 μA accompanied by a high electron mobility of 7 cm 2 V -1 s -1 at a drain voltage ( V DS ) of 1 V. We successfully showcased a homogeneous CMOS inverter utilizing 2D-TMDC which exhibits an impressive voltage gain of 7 at V DD = 5 V. Moreover, this effective polarity control approach was further expanded upon to successfully demonstrate a range of logic circuits such as AND, OR, NAND, NOR logic gates, and SRAM. The proposed methodology possesses significant promise for facilitating the advancement of high-density circuitry components utilizing 2D-TMDC.