Enhanced transport and transistor performance with oxide seeded high-κ gate dielectrics on wafer-scale epitaxial graphene.

Hollander, Matthew J; Labella, Michael; Hughes, Zachary R; Zhu, Michael; Trumbull, Kathleen A; Cavalero, Randal; Snyder, David W; Wang, Xiaojun et al. · Nano Lett · 2011

basic_science · Level V

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Abstract

We explore the effect of high-κ dielectric seed layer and overlayer on carrier transport in epitaxial graphene. We introduce a novel seeding technique for depositing dielectrics by atomic layer deposition that utilizes direct deposition of high-κ seed layers and can lead to an increase in Hall mobility up to 70% from as-grown. Additionally, high-κ seeded dielectrics are shown to produce superior transistor performance relative to low-κ seeded dielectrics and the presence of heterogeneous seed/overlayer structures is found to be detrimental to transistor performance, reducing effective mobility by 30-40%. The direct deposition of high-purity oxide seed represents the first robust method for the deposition of uniform atomic layer deposited dielectrics on epitaxial graphene that improves carrier transport.