Graphene wafers 100mm in diameter have been produced by researchers in the Electro-Optics Center (EOC) materials division at Penn State, making them the largest diameter commercially available for silicon carbide wafers.

Graphene is an ideal candidate for many high-speed computing applications in the multibillion-dollar semiconductor device industry. The researchers found an electron moved at 1/300th the speed of light through graphene - potentially enabling terahertz computing, at processor speeds 100 to 1,000 times faster than silicon they claim.
 
Using a process called silicon sublimation, they thermally processed silicon carbide wafers in a high temperature furnace until the silicon migrated away from the surface, leaving behind a layer of carbon that formed into a one-to two-atom-thick film of graphene on the wafer surface. The wafers at 100mm in diameter exceeded the previous demonstration of 50mm.
 
According to EOC materials scientist Joshua Robinson," Penn State is currently fabricating field effect transistors on the 100 mm graphene wafers and will begin transistor performance testing shortly."
 
They hope to improve the speed of electrons in graphene made from silicon carbide wafers to closer to the theoretical speed, approximately 100 times faster than silicon. "That will require improvements in the material quality," says Robinson, "but the technology is new and there is plenty of room for improvements in processing."
 
In addition to silicon sublimation, the team is developing the synthesis and device fabrication of graphene on silicon as a means to achieve wafer diameters exceeding 200mm, a necessity for integrating graphene into the existing semiconductor industry. With the support of the Naval Surface Warfare Center in Crane, Ind., EOC researchers are initially focusing on graphene materials to improve the transistor performance in various radio frequency (RF) applications.
 
Graphene is the two-dimensional form of graphite and consists of tightly bound carbon atoms in a hexagonal arrangement resembling chicken wire. With its remarkable physical, chemical and structural properties, graphene is being studied worldwide for electronics, displays, solar cells, sensors, and hydrogen storage.