Researchers have developed a stable platform for manufacturing electronic devices made of graphene. Graphene field effect transistors (GFETs) made with this platform are shown to be stable against atmospheric influences and uniform in their properties across a batch of more than 500 devices.
Photo: Monolayer graphene on SiO2/Si wafer.
The adoption of graphene production at industrial scales is an imperative for the use of this multifunctional material in a variety of applications that have arisen in the past decade. Graphene’s superb electrical, optical, thermal, mechanical, and chemical properties are often demonstrated on a few micron-size samples in strictly controlled conditions, whereas the market demands reproducible operation of a multitude of devices in atmospheric conditions on a large scale. Now a team of researchers formed an industrial-academic partnership across France, Spain, and the UK to tackle this obstacle in a way that would lead to faster adoption of graphene technology in microelectronics.
In a paper published in the journal Applied Physics Letters in the final weeks of 2016, researchers from GERAC, Thales, CNRS, the University of Cambridge and Graphenea reported on a statistical analysis and consistency of electrical performance of GFETs on a large scale. The devices were protected and passivated with two protective layers that ensured that the conductance minimum characteristic of electrical transport in graphene is visible most of the time and that it fluctuates very little from device to device. The intrinsic charge doping was below 5x1011 cm-2. In addition, this approach removed the hysteresis effect that usually degrades graphene device performance in air. Importantly, the devices were also stable in time, with unchanged performance over the course of one month.
Image: Passivated GFET performs better than unpassivated.
“We have consistently been working hard on developing platforms for integration of graphene in industrial scale processes. This work, a result of several projects of the European Commission, demonstrates that we have gone very far in this direction and that we can expect graphene microelectronic devices to start showing up in real products very soon”, says Amaia Zurutuza, the Scientific Director of Graphenea.