Graphene is a single sheet of carbon atoms arranged in a honeycomb structure and it spontaneously forms on silicon carbide (the same material used for household LED lighting). Research at the Georgia Institute of Technology has shown that this form of graphene can be used to make transistors, which are fundamental components of solid-state electronics. However, currently graphene transistors are limited to non-digital applications because of a fundamental physical property of graphene. The research proposed here overcomes this fundamental problem using innovative modifications of graphene, thereby enabling graphene transistors to be used in digital electronics. If the objectives of this proposal are successfully achieved then graphene may have a significant impact in the electronics industry by providing an alternative to the ubiquitous silicon-based electronics. Graphene-based electronics may be faster and more energy-efficient than silicon-based electronics, and they are therefore of significant importance for society.
This research aims to develop digital graphene electronics on a silicon carbide platform. The key goals are to demonstrate: (1) high on-to-off ratios in field effect transistors (2) field effect transistor switching speeds that are comparable to or exceed those of silicon based transistors. (3) low power consumption. The scope of the research is presented below; For 5 decades, digital electronics has seen a relentless exponential growth in performance, but the growth will soon end, due to the physical limitations of silicon, on which the electronics industry almost exclusively relies. This "end of Moores law" scenario has been looming for some time, and no viable alternatives have been found. As first proposed by researchers at the Georgia Institute of Technology in 2003, graphene that is epitaxially grown on electronics grade silicon carbide is one of the most promising contenders to succeed silicon. This research aims to provide a proof of principle, by demonstrating that high-speeds and low power field effect transistors are feasible. The methods and approaches to be used This research builds on a decade of work at the Georgia Institute of Technology in the field of epitaxial graphene. In that time, high-speed transistors were demonstrated. Due to a lack of a bandgap in graphene, however, these transistors cannot be fully turned off and therefore they are not energy efficient. Recent research has found two ways to overcome this problem. One relies on the observation that a graphene layer grown on the silicon-terminated face of hexagonal silicon carbide is actually a semiconductor. If its mobility turns out to be sufficiently great, then it can be used for high performance digital electronics. The second method relies on the observation that charge carriers efficiently quantum mechanically tunnel over physical gaps in graphene ribbons. The tunneling current can be tuned using electrostatic gates to form ultra-thin body field effect tunneling transistors. In principle, this type of transistor is expected to operate at very high speed with low power consumption. The intellectual significance of the activity If this research successfully achieves its ultimate goal, then it has the potential to revolutionize the electronics industry and to kick-off the long awaited "age of graphene electronics." Even if this lofty technological goal is not reached, then none-the-less, this research will represent a significant advance in graphene science.
