MoS2-on-AlN Enables High-Performance MoS2 Field-Effect Transistors through Strain Engineering

ACS Appl Mater Interfaces. 2020 Dec 9;12(49):54972-54979. doi: 10.1021/acsami.0c16079. Epub 2020 Nov 30.

Abstract

Molybdenum disulfide (MoS2) has substantial application prospects in the field of electronic devices. The fabrication of devices of excellent quality based on MoS2 films is an important research direction. In this study, based on the atomic layer deposition technique, large-area MoS2 films were grown, and top-gate MoS2-based field-effect transistor arrays were fabricated on four substrates (AlN, GaN, sapphire, and SiO2). It was found that the interface defects that were introduced by lattice mismatch and roughness of the growth substrate could cause an exponential (102) drop in mobility. Because of the small lattice mismatch and excellent surface quality, transistors on the AlN substrate have shown an enhanced mobility (10.45 cm2 V-1 s-1) compared to transistors on the other substrates. This study proves that the AlN substrate is a superior substrate for large-area and high-performance MoS2 film synthesis. This result can also be applied in higher-level microelectronic systems, such as in digital logic circuit design.

Keywords: ALD; AlN; FET arrays; MoS2; lattice mismatch.