Improved electrical performance of multilayer MoS2 transistor by incorporating Al into host HfO2 as gate dielectric

Abstract

The effects of incorporating Al into HfO2 as gate dielectric on the back-gated MoS2 transistor are investigated. Hf0.5Al0.5O as gate dielectric exhibits excellent electrical characteristics: on/off ratio of 1.8 ×107, carrier mobility of 49.3 cm2/(V • s), subthreshold swing of 118 mV dec-1, interface-state density of 2.3 ×1012 eV-1 cm-2, due to the Al incorporation into the HfO2 can passivate the defective states induced by oxygen vacancies and improve the dielectric densification and uniformity to obtain an excellent MoS2/Hf1-xAlxO interface. Besides, the intrinsic carrier mobility of 100 cm2 V-1 s-1 and contact resistance of 11.1 k/μm indicates that the contact resistance is a main factor limiting the mobility.