Epitaxial (111) Films of Cu, Ni, and Cu$_xNi$_y$ on α-Al$_2$O$_3$(0001) for Graphene Growth by Chemical Vapor Deposition

David L. Miller; Mark W. Keller; Justin M. Shaw; Ann N. Chiaramonti; Robert R. Keller

doi:10.1063/1.4754013

paper

Epitaxial (111) Films of Cu, Ni, and Cu $_{x} N i$ _y $o n α - A l$ _2 $O$ _3$(0001) for Graphene Growth by Chemical Vapor Deposition

arXiv:1205.0833 · doi:10.1063/1.4754013

Abstract

Films of (111)-textured Cu, Ni, and Cu $_{x}$ Ni $_{y}$ were evaluated as substrates for chemical vapor deposition of graphene. A metal thickness of 400 nm to 700 nm was sputtered onto a substrate of $α -$ Al $_{2}$ O $_{3}$ (0001) at temperatures of 250 C to 650 C. The films were then annealed at 1000 C in a tube furnace. X-ray and electron backscatter diffraction measurements showed all films have (111) texture but have grains with in-plane orientations differing by $6 0^{\circ}$ . The in-plane epitaxial relationship for all films was $[110]_{m e t a l}$ || $[10 1 ˉ 0]_{A l_{2} O_{3}}$ . Reactive sputtering of Al in O $_{2}$ before metal deposition resulted in a single in-plane orientation over 97 % of the Ni film but had no significant effect on the Cu grain structure. Transmission electron microscopy showed a clean Ni/Al $_{2}$ O $_{3}$ interface, confirmed the epitaxial relationship, and showed that formation of the $6 0^{\circ}$ twin grains was associated with features on the Al $_{2}$ O $_{3}$ surface. Increasing total pressure and Cu vapor pressure during annealing decreased the roughness of Cu and and Cu $_{x}$ Ni $_{y}$ films. Graphene grown on the Ni(111) films was more uniform than that grown on polycrystalline Ni/SiO $_{2}$ films, but still showed thickness variations on a much smaller length scale than the distance between grains.

Epitaxial (111) Films of Cu, Ni, and Cu $_{x} N i$ _y $o n α - A l$ _2 $O$ _3$(0001) for Graphene Growth by Chemical Vapor Deposition

Abstract

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Epitaxial (111) Films of Cu, Ni, and Cux​Ni_yonα−Al_2O_3$(0001) for Graphene Growth by Chemical Vapor Deposition

Abstract

References in corpus (4)

Cited by in corpus (5)

Epitaxial (111) Films of Cu, Ni, and Cu $_{x} N i$ _y $o n α - A l$ _2 $O$ _3$(0001) for Graphene Growth by Chemical Vapor Deposition