| Graphene is a promising new material with excellent electrical and thermal properties. Its electrical properties are determined by its unique planar hexagonal carbon carbon structure, as well as the sp2 hybridization which is responsible for excellent charge-transport properties. Electron mobilities exceeding 200,000 cm2V-1s-1 have been measured. While these properties suggest the potential use of single layer graphene as an active material in high performance devices, the absence of a band gap prevents the use of monolayer graphene as a channel material for field-effect transistors. Bilayer graphene can overcome this shortcoming since it has been shown to exhibit a gap under the application of an applied external electric field. Other major problems when dealing with graphene is that the current conventional growth methods, especially chemical vapor deposition (CVD) and epitaxial growth (SiC) need a transfer step to transfer the graphene onto a working substrate. This transfer process has been shown to degrade the electrical properties of the graphene layer. It is shown in this work that an alternate unconventional growth method using pulsed laser deposition (PLD) is possible to obtain graphene directly onto the insulator (SiO 2) on the Si substrate. A solid carbon source is used in the current work compared to the gas based carrier source used in the conventional chemical vapor deposition technique. Furthermore, we discuss direct fabrication of graphene based devices (field-effect transistors and Hall-bar structure) using this newer PLD based graphene growth method and the difficulties faced during the fabrication of such devices. |
