Investigation of charge trapping mechanism in MoS2 field effect transistor by incorporating Al into host La2O3 as gate dielectric

Abstract

The charge trapping effect plays a key role in multi-bit memory devices and brain-like neuron devices. Herein, MoS2 field effect transistors are fabricated, incorporating Al into host La2O3 as the gate dielectric, which exhibit excellent electrical properties with an on–off ratio in the memory window of ∼106 and a memory window ratio of ∼40%. Furthermore, the charge trapping and de-trapping processes were systematically studied, and the time constants are obtained from time-domain characteristics. Making use of the charge trapping effect, the threshold voltage of the device can be continuously adjusted. The oxide layer trap density and the interface state trap density are extracted using the charge separation method. These theoretical studies provide a deeper understanding of ways to control the charge trapping process, benefitting the commercialization of two-dimensional electronic devices and the development of new charge trapping devices.