  Graphene has been attracting great interest because of its distinctive band
structure and physical properties. Today, graphene is limited to small sizes
because it is produced mostly by exfoliating graphite. We grew large-area
graphene films of the order of centimeters on copper substrates by chemical
vapor deposition using methane. The films are predominantly single layer
graphene with a small percentage (less than 5%) of the area having few layers,
and are continuous across copper surface steps and grain boundaries. The low
solubility of carbon in copper appears to help make this growth process
self-limiting. We also developed graphene film transfer processes to arbitrary
substrates, and dual-gated field-effect transistors fabricated on Si/SiO2
substrates showed electron mobilities as high as 4050 cm2V-1s-1 at room
temperature.
