Graphene Presents a Second Chance for British Semiconductors

  • 19 April 2024
  • Business, Technology
  • Professor Sir Colin Humphreys CBE FRS FREng FIMMM FInstP

This year, we in the UK are celebrating a very important anniversary. In 2004, two scientists from the University of Manchester used a roll of sticky tape to make an amazing discovery. When Andre Geim and Konstantin Novoselov used the tape to peel layers of graphite apart from one another, they isolated for the first-time small flakes of a single layer of graphite, called graphene, which became known as the ‘wonder material.’ This proved to be an amazing scientific breakthrough because graphene has some world-leading properties, e.g., it is the best conductor of electricity in the world. For this discovery, they were awarded the Nobel Prize for Physics in 2010.

While the intervening years have seen the mechanical properties of graphene exploited in construction and textile applications, its arguably more-impressive electronic properties, like very high electron mobility and thermal conductivity, proved more elusive for use in real-world electronic devices. This results from the difficulty in creating large-area, device-quality, one-atom-thick sheets of graphene at a scale necessary for mass producing electronic devices. Here again, though, British science – and Britain’s first-class universities – won the race to scale up graphene from the small flakes produced by Geim and Novoselov to large-area graphene layers, 150 mm (6 inch) in diameter, but still only a single atomic layer of carbon atoms thick.

In 2015, before I moved to Queen Mary University of London, I was operating a research lab at the University of Cambridge’s Department of Materials Science and Metallurgy. Two of the scientists working with me, Simon Thomas and Ivor Guiney, invented and developed a deposition process that enables a device-quality, contamination-free graphene layer to form on a substrate wafer (we initially used sapphire). We realised that these wafers could produce hundreds, or even thousands, of devices with graphene as the conductive element, and that these devices could be packaged for use in mass-produced electronics. We founded Paragraf to exploit our invention, as we could see the massive commercial implications of graphene electronics. Today, researchers around the world are attempting to catch up with this innovation. For example, China is investing heavily to develop scalable graphene electronics.

Paragraf has taken this project from lab-to-fab, incorporating wafer-scale monolayer graphene into the semiconductor manufacturing process. That process has so far yielded graphene sensors that can be used as Hall effect magnetic sensors in quantum computing, for example, and in graphene field effect transistors (GFETs) that can detect a wide range of biological molecules. Next, wafer-scale graphene will be used to make more complex devices such as those used in Radio Frequency circuits.

Graphene was the first two-dimensional (2D) material discovered. Since then, a range of other 2D materials have been produced. Scientists worldwide, including at Paragraf, are researching using a combination of graphene and other 2D materials to produce next-generation electronic devices which are faster, and consume less energy, than silicon devices. This is important because the electricity consumption of silicon devices globally is increasing exponentially, largely driven by the increase in Artificial Intelligence, which uses huge databases in data centres, posing a major threat to reaching Net Zero. Ultra-low-energy consumption 2D electronic devices have the potential to be an essential enabler of Net Zero.

British engineer Geoffrey Dummer is credited as being the first person to conceive a silicon integrated circuit, described in the paper he presented at the US Electronic Components Symposium in 1952. His efforts to bring this innovation to fruition, however, were outpaced by better-funded American contemporaries, and a potential leading role for British industry in the semiconductor revolution collapsed because of the lack of financial support.

The UK world lead in manufacturable graphene devices represents a renewed opportunity for the UK to spearhead the next generation of 2D semiconductor devices. Paragraf now has two facilities in Cambridgeshire, one dedicated to the R&D of graphene/2D electronic devices and the other to manufacturing them. It has attracted a significant amount of funding from British and overseas investors. If the UK is prepared to match the financial investment in semiconductors provided by other developed countries, this will enable our universities and industries to compete on a level playing field with them.  In particular, it will enable the UK to maintain its world lead in 2D devices, leapfrogging ahead of silicon and helping to enable Net Zero. The UK will then massively reap the benefits of our isolation of graphene 20 years ago for the future health and wealth of our country.

The author is Professor of Materials Science at Queen Mary University of London. He is also a co-founder and Chief Science Officer at Paragraf.