Enhanced Transport and Transistor Performance with Oxide Seeded High-κ Gate Dielectrics on Wafer-Scale Epitaxial Graphene

• Published in: Nano letters 2011-09, Vol.11 (9), p.3601-3607
• Main Authors: Hollander, Matthew J, LaBella, Michael, Hughes, Zachary R, Zhu, Michael, Trumbull, Kathleen A, Cavalero, Randal, Snyder, David W, Wang, Xiaojun, Hwang, Euichul, Datta, Suman, Robinson, Joshua A
• Format: Article
• Language: English
• Subjects: Applied sciences; Carrier transport; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Deposition; Dielectric thin films; Dielectrics; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Electronics; Epitaxy; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; Graphene; Materials science; Molecular electronics, nanoelectronics; Oxides; Physics; Seeds; Semiconductor devices; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Specific materials; Transistors
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl201358y

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.