Liquid Metal Oxide-assisted Integration of High-k Dielectrics and Metal Contacts for Two-Dimensional Electronics

TL;DR

This paper introduces a liquid metal oxide-assisted method for integrating high-k dielectrics with 2D semiconductors, enabling high-performance transistors with smooth interfaces and scalable device integration.

Contribution

The work presents a novel liquid metal oxide-assisted technique for uniform high-k dielectric integration on 2D materials, addressing a key challenge in 2D nanoelectronics.

Findings

Achieved subthreshold swing of 74.5 mV/dec in 2D WS2 transistors

Demonstrated low gate leakage current below 10^-6 A/cm^2

Enabled scalable van der Waals integration of contacts and dielectrics

Abstract

Two-dimensional van der Waals semiconductors are promising for future nanoelectronics. However, integrating high-k gate dielectrics for device applications is challenging as the inert van der Waals material surfaces hinder uniform dielectric growth. Here, we report a liquid metal oxide-assisted approach to integrate ultrathin, high-k HfO2 dielectric on 2D semiconductors with atomically smooth interfaces. Using this approach, we fabricated 2D WS2 top-gated transistors with subthreshold swings down to 74.5 mV/dec, gate leakage current density below 10-6 A/cm2, and negligible hysteresis. We further demonstrate a one-step van der Waals integration of contacts and dielectrics on graphene. This can offer a scalable approach toward integrating entire prefabricated device stack arrays with 2D materials. Our work provides a scalable solution to address the crucial dielectric engineering challenge for 2D semiconductors, paving the way for high-performance 2D electronics.