High‐Performance Graphene‐Dielectric Interface by UV‐Assisted Atomic Layer Deposition for Graphene Field Effect Transistor

Abstract

Abstract The deposition of high‐quality dielectric films on graphene surfaces is crucial in fabricating high‐performance graphene‐based electronics. In this study, the first application of UV‐assisted atomic layer deposition (UV‐ALD) to graphene surfaces and the fabrication of graphene field‐effect transistors (GFETs) with UV‐ALD Al2O3 dielectric thin films is demonstrated. Optimal UV irradiation (5 s per cycle) during the ALD process results in denser and smoother Al2O3 dielectric films deposited on the graphene surface with the intimate graphene‐dielectric interface, while excessive UV irradiation in turn prohibits the film nucleation. As a result, the GFETs with a high‐quality dielectric layer deposited by UV‐ALD show improved performance with a Dirac voltage close to 0 V and hole mobility of 1221 cm2 V−1 s−1, i.e., > 200% increase compared to those with thermal ALD. This study demonstrates that UV‐ALD is an effective and simple option to realize a high‐quality interface between 2D materials and ultra‐thin dielectric films.

Keywords

• dielectric films
• graphene field effect transistors
• surface functionalization
• UV‐assisted atomic layer deposition