High-Performance CMOS Inverter Array with Monolithic 3D Architecture Based on CVD-Grown n-MoS2 and p-MoTe2.

Abstract

In thiswork, monolithic three-dimensional complementary metal oxide semiconductor (CMOS) inverter array has been fabricated, based on large-scale n-MoS2 and p-MoTe2 grown by the chemical vapor deposition method. In the CMOS device, the n- and p-channel field-effect transistors (FETs) stack vertically and share the same gate electrode. High k HfO2 is used as the gate dielectric. An Al2 O3 seed layer is used to protect the MoS2 from heavily n-doping in the later-on atomic layer deposition process. P-MoTe2 FET is intentionally designed as the upper layer. Because p-doping of MoTe2 results from oxygen and water in the air, this design can guarantee a higher hole density of MoTe2 . An HfO2 capping layer is employed to further balance the transfer curves of n- and p-channel FETs and improve the performance of the inverter. The typical gain and power consumption of the CMOS devices are about 4.2 and 0.11 nW, respectively, at VDD of 1V. The statistical results show that the CMOS array is with high device yield (60%) and an average voltage gain value of about 3.6 at VDD of 1 V. This work demonstrates the advantage of two-dimensional semi-conductive transition metal dichalcogenides in fabricating high-density integrated circuits.