Benchmarking monolayer MoS2 and WS2 field-effect transistors

Amritanand Sebastian,Joan M Redwing,Saptarshi Das,Rahul Pendurthi,Tanushree H Choudhury

doi:10.1038/s41467-020-20732-w

Amritanand Sebastian, Joan M Redwing + Show 3 more

Open Access

https://doi.org/10.1038/s41467-020-20732-w

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Journal: Nature Communications	Publication Date: Jan 29, 2021
Citations: 264	License type: open-access

Affiliation: Pennsylvania State University

Abstract

Here we benchmark device-to-device variation in field-effect transistors (FETs) based on monolayer MoS2 and WS2 films grown using metal-organic chemical vapor deposition process. Our study involves 230 MoS2 FETs and 160 WS2 FETs with channel lengths ranging from 5 μm down to 100 nm. We use statistical measures to evaluate key FET performance indicators for benchmarking these two-dimensional (2D) transition metal dichalcogenide (TMD) monolayers against existing literature as well as ultra-thin body Si FETs. Our results show consistent performance of 2D FETs across 1 × 1 cm2 chips owing to high quality and uniform growth of these TMDs followed by clean transfer onto device substrates. We are able to demonstrate record high carrier mobility of 33 cm2 V−1 s−1 in WS2 FETs, which is a 1.5X improvement compared to the best reported in the literature. Our experimental demonstrations confirm the technological viability of 2D FETs in future integrated circuits.

Highlights

We benchmark device-to-device variation in field-effect transistors (FETs) based on monolayer MoS2 and WS2 films grown using metal-organic chemical vapor deposition process
We attribute our accomplishments to the epitaxial growth of highly crystalline 2D monolayers on sapphire substrate via metal-organic CVD (MOCVD) technique at 1000 °C using chalcogen and sulfur precursors that minimize carbon contamination in the film, as well as to the clean transfer of the film from the growth substrate to the device fabrication substrate
After growth the substrate was cooled in H2S to 300 °C to inhibit decomposition of the MoS2 and WS2 films

Summary

Introduction

We benchmark device-to-device variation in field-effect transistors (FETs) based on monolayer MoS2 and WS2 films grown using metal-organic chemical vapor deposition process. While initial demonstrations of prototype devices relied on exfoliated flakes, the 2D community has rapidly transitioned towards the growth of large-area films to address manufacturing needs for any commercial applications. In this context, chemical vapor deposition (CVD)[22,23] and metal-organic CVD (MOCVD)[7,24] are the most promising techniques, enabling growth of high quality 2D materials with different thermal budgets on various substrates.

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