S. A. Giamini

Graphene A hexagonal honeycomb lattice of carbon. In its basic form it is a one-atom thick (2D) sheet. Interesting properties: Better electric conductor than copper, high mobility, ballistic transport, great thermal conductivity, harder than diamond, almost completely transparent and more… Dedkov et. al Epitaxial Graphene on Metals

Motivation Grow graphene by CVD with Ni as catalyst Understand and describe methods and techniques that could help graphene integration and application Single layer Graphene - Good quality - Large area Thermal budget Growth temperature IC industry Post-silicon era

Growth of graphene by CVD Growth process Growth chamber Transfer process

Graphene on nickel foil 25 μm – Typical Growth at 600 ° C I 2D /I G = 0.7 Fwhm = 65 3 layers or more Low defects Non uniform

| Copper foil side | Nickel foil side Deposition of copper on nickel foil in electrochemical cell Deposition of amount equivalent to ~10 nm of copper(100)

Graphene (transferred) from nickel foil 25 μm –copper decorated Growth at 600 ° C I 2D /I G > 3 Fwhm = 30 I D /I G ~1 high Growth over the entire surface Unconnected areas

Graphene Raman I 2D /I G mapping and XPS spectra C-sp 2, eV C-sp 3, eV C=O, ~287 eV XPS shows well defined sp 2 peak with very little "contaminants" Raman I 2D /I G mapping shows good uniformity with ratio > 1.5

Graphene from nickel foil 25 μm – copper decorated Importance of surface roughness I 2D /I G > 3 I D /I G ~ 0.15 Low defect – Single Layer Graphene I 2D /I G > 3 I D /I G ~ 1 High defect –Single Layer Graphene

Graphene STM and lattice measurements Line profiles in agreement with theoretical values STM showing the honeycomb lattice of graphene

Conclusions Graphene growth by CVD Nickel as the catalyst Single layer growth on copper decorated nickel Low temperature process (600 ° C) Tune growth parameters for continuous mm-sized graphene Investigation of the role of copper during growth

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