IBM scientists hit 100 GigaHertz with graphene transistor

In a recent paper published in Science IBM scientists published results with the world’s fastest graphene transistor. The article entitled ”100-GHz Transistors from Wafer-Scale Epitaxial Graphene” was published in Science 5 February 2010: Vol. 327 records a milestone in the use of carbon in radio frequency electronics. Most importantly the graphene was grown epitaxially at wafer-scale using technology compatible with current silicon production facilities. 

The abstract of the article;
”The high carrier mobility of graphene has been exploited in field-effect transistors that operate at high frequencies. Transistors were fabricated on epitaxial graphene synthesized on the silicon face of a silicon carbide wafer, achieving a cutoff frequency of 100 gigahertz for a gate length of 240 nanometers. The high-frequency performance of these epitaxial graphene transistors exceeds that of state-of-the-art silicon transistors of the same gate length.”

Graphene has long been considered a high potential candidate for future transistors thanks to its molecular characteristics.Graphene consists of a single layer of carbon atoms arranged in hexagonal patterns, much like the structure of your ordinary honeycomb. The electrons can propagate extremely fast across the atoms, enabling the high frequency demonstrated by the article.

The gate length was humble 240nm, which leaves plenty of room for improvements. The transistor cut-off frequency reported in the article, 100GHz, is 2.5 times higher than the best silicon transistor of the same gate length. The transistor architecture used a metal top-gate design with a high dielectric constant oxide and a novel gate insulator.

The work, supported by DARPA, demonstrated that graphene is within reach for use in integrated circuits and high-performance solutions.