Interface passivation and trap reduction via hydrogen fluoride for molybdenum disulfide on silicon oxide back-gate transistors. (6th March 2018)

• Record Type: Journal Article
• Authors: Hu, Yaoqiao; Yip, Pak San; Tang, Chak Wah; Lau, Kei May; Li, Qiang
• Is Part Of: Semiconductor science and technology. Volume 33:Number 4(2018:Apr.)
• Publication Date: 2018-03-06
• Subjects: interface passivation -- MoS2 -- hydrogen fluoride -- MoS2/oxide interface -- mobility -- XPS -- first-principles calculation; Semiconductors -- Periodicals; 621.38152
• DOI: 10.1088/1361-6641/aaa224
• Languages: English
• ISSNs: 0268-1242

Abstract

Abstract: Layered semiconductor molybdenum disulfide (MoS2 ) has recently emerged as a promising material for flexible electronic and optoelectronic devices because of its finite bandgap and high degree of gate control. Here, we report a hydrogen fluoride (HF) passivation technique for improving the carrier mobility and interface quality of chemical vapor deposited monolayer MoS2 on a SiO2 /Si substrate. After passivation, the fabricated MoS2 back-gate transistors demonstrate a more than double improvement in average electron mobility, a reduced gate hysteresis gap of 3 V, and a low interface trapped charge density of ∼5.8 × 10 11 cm −2 . The improvements are attributed to the satisfied interface dangling bonds, thus a reduction of interface trap states and trapped charges. Surface x-ray photoelectron spectroscopy analysis and first-principles simulation were performed to verify the HF passivation effect. The results here highlight the necessity of a MoS2 /dielectric passivation strategy and provides a viable route for enhancing the performance of MoS2 nano-electronic devices.