Process shows potential for graphene scale-up

The remarkable properties of graphene are being mobilised with a new microfabrication technology developed at Griffith University that may well launch the next generation of off-the-shelf, low-cost micro-devices.

Developed by Dr Francesca Iacopi, from Griffith University’s Queensland Micro- and Nanotechnology Centre, the microfabrication process enables production-scale manufacturing of a superior and versatile material that can be used to produce biocompatible, chemically resistant and highly sensitive sensor devices.

“We believe this process will change the way we live by providing the ultimate in device miniaturisation. It will influence a lot of different sectors because many modern applications relying on micro- and nano-devices will be able to advance by incorporating this technology,” said Iacopi.

“For example, medicine is just one area where this technology can be applied. Someone with diabetes could have a nanochip sitting on their skin - mass produced with the help of our microfabrication process - continuously monitoring their blood, and any changes can be relayed directly to a doctor.”

Graphene was first isolated in the laboratory about a decade ago. It is pure carbon and comes in the form of a very thin, almost transparent sheet one atom thick. Despite its thinness, graphene is exceptionally strong and conducts heat and electricity with great efficiency.

Its mechanical, electrical, thermal and optical properties are well documented, along with the potential it holds in the fabrication of new and advanced micro-devices.

However, progress to date has been slow because synthesising high-quality graphene onto silicon wafers or slices, which act as semiconductors, is difficult. The production of these wafers would enable the cost-effective mass production of such devices.

This has now been overcome with Iacopi, working with three PhDs, a postdoctorate, national and international collaborators, developing a novel low-temperature process to synthesise graphene by using a metal alloy catalyst that produces a continuous, high-quality, controllable graphene film.

The work has also resulted in the development of a strategy for patterning graphene so that it will grow only on a pre-patterned silicon carbide (SiC) layer on silicon.

“Until now, high-quality graphene was restricted to the use of expensive SiC wafers or the use of complicated transfer procedures to silicon wafers. A cheaper substrate and a simpler methodology were badly needed to ensure the micro-devices would be cost-competitive,” said Iacopi.

“At Griffith, we were the first to develop a method for depositing a very high-quality thin layer of SiC on to 300 mm silicon wafers. This work is still very early but the prospects are very exciting and broad-ranging.”

Iacopi and her team are seeking industry partners to leverage the technology in an industrial type of product.