Epitaxial Graphene Surface Preparation for Atomic Layer Deposition of Al2O3
Abstract
Atomic layer deposition was employed to deposit relatively thick ( 30 nm) aluminum oxide (Al2O3) using trimethylaluminum and triply-distilled H2O precursors onto epitaxial graphene grown on the Si-face of silicon carbide. Ex situ surface conditioning by a simple wet chemistry treatment was used to render the otherwise chemically inert graphene surface more amenable to dielectric deposition. The obtained films show excellent morphology and uniformity over large ( 64 mm2) areas (i.e., the entire sample area), as determined by atomic force microscopy and scanning electron microscopy. X-ray photoelectron spectroscopy revealed a nearly stoichiometric film with reduced impurity content. Moreover, from capacitance-voltage measurements a dielectric constant of 7.6 was extracted and a positive Dirac voltage shift of 1.0 V was observed. The graphene mobility, as determined by van der Pauw Hall measurements, was not affected by the sequence of surface pretreatment and dielectric deposition.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2011
- Accession Number
- ADA546142
Entities
People
- C. R. Eddy Jr.
- D. Kurt Gaskill
- Glenn G. Jernigan
- J. K. Hite
- J. L. Tedesco
- N. Y. Garces
- Neeraj Nepal
- Virginia D. Wheeler
Organizations
- United States Naval Research Laboratory