Silicon microchips underpin our modern lives. They are at the heart of our smartphones and laptops. They also play critical roles in electric vehicles and renewable energy technology.
Author
- Peter Gammon
Professor of Power Electronic Devices, School of Engineering, University of Warwick
Today, more than three-quarters of microchips, also known as semiconductors, are produced in Asia. But in the 1990s, chip production was more widely distributed across the globe - and the UK punched above its weight.
Scotland's central belt - the area of highest population density, including Glasgow, Edinburgh and the towns surrounding them - became known as "Silicon Glen", employing 50,000 people in the electronics industry at its peak.
The region exported everything from PCs to Playstation chips. Multinational companies like NEC, Motorola and Texas Instruments operated major facilities there. In the 2000s, the dotcom crash triggered industry-wide consolidation and a shift to lower-cost manufacturing facilities in east Asia. The UK's domestic capability was almost wiped out .
But the UK semiconductor industry is quietly bouncing back. A new wave of companies is focusing on microchips designed for clean energy technology. These chips power electric vehicles and are vital for integrating renewable energy into the grid. They're also widely used in data centres.
Whereas most microchips are based on the element silicon, these new chips are made from "compound" semiconductors: silicon carbide (SiC) and gallium nitride (GaN).
The chemical compounds SiC and GaN offer a range of attractive properties, including the ability to conduct an electrical current efficiently at high temperatures and to withstand electric fields more than nine times stronger than those silicon on its own can tolerate before breaking down.
This allows SiC chips to be nine times thinner than equivalent silicon chips. This in turn results in lower resistance to electrical current in the devices they're used in - translating to greater efficiency.
If you know how hot a phone or laptop charger can get, you've experienced inefficient power conversion. This heat is the result of silicon chips switching thousands of times per second to transform one type of electrical current, known as AC, to another, called DC.
In the case of chargers, 230 volts (V) in AC from the wall socket is transformed into the 19V in DC that a laptop battery needs - with some energy lost as heat. SiC and GaN devices switch faster than their silicon counterparts and dissipate less energy as waste heat.
This makes them ideal for high-performance, compact and energy-efficient charging systems. GaN-based wall chargers are now becoming common and they're smaller, lighter and more efficient.
This efficiency boost is vital for electric vehicles too, in which a large power converter changes DC electricity coming from the batteries to AC electricity, as required by the electric motor. SiC-based power converters can reduce the energy lost by this converter by over 60% , a saving that means the car's range can be extended by up to 5%.
Producing SiC and GaN requires complex, expensive and energy-intensive manufacturing processes. It wasn't until the 2010s that materials like these could be produced at the scale and cost needed for mass market adoption. Silicon carbide, for instance, must be grown under extreme temperatures and pressures over the course of a week, forming a small cylindrical crystal - or boule - often less than 5cm long.
In contrast, to source silicon for chips, metre-long silicon ingots are pulled continuously from a vat of molten silicon, known as the melt. This fundamental difference drives the cost gap: SiC chips remain around three times more expensive than their silicon counterparts, posing a challenge for widespread adoption. Nevertheless, SiC chips remain vital for specific applications.
New industry hubs
In March 2024, US-based Vishay Intertechnology acquired Newport Wafer Fab - one of the UK's last major semiconductor plants - for US$177 million (£132 million). In March 2025, it announced a further £250 million investment to expand production, modernise equipment and grow the workforce at the Welsh facility. Around 400 jobs were safeguarded.
The focus in Newport will be on compound semiconductors, beginning with SiC chips destined for electric vehicles, data centres and industrial applications. At capacity, thousands of silicon carbide wafers, or discs, will be processed every month. It is from these wafers that the chips are cut. Measuring 200mm in diameter, each wafer will yield enough SiC chips to supply more than 15 electric vehicle power converters.
Chip manufacturing has also returned to Silicon Glen. In Lochgelly, Fife, Clas-SiC Wafer Fab was founded in 2017 and it too produces SiC chips. The processing carried out at Lochgelly is similar to that at Vishay, except that Clas-SiC operates what's known as a foundry model, producing devices to the designs of international customers. This model separates out the design and manufacturing aspects of the chip industry.
Compound semiconductors also play a crucial role in national security. The UK Ministry of Defence recently made key investments in UK semiconductors. One of these aims to secure the domestic supply of gallium arsenide and gallium nitride chips, which are critical for radar systems and fighter jets.
World-class research in UK universities is fundamental to success stories like these. More than a decade of coordinated public investment - particularly through the 2010s - helped build globally recognised academic expertise.
At the University of Warwick, for example, our team leads national efforts to develop the next generation of SiC devices. We are focusing on ultra-high-voltage power devices for use in the trains and ships of the future, along with the grid and in radiation-hardened power electronics for space, with funding from the UK government's semiconductor strategy .
As the UK government looks to drive growth through clean energy and advanced manufacturing, its recent support for this sector via the UK semiconductor strategy has been significant. The forthcoming industrial strategy presents a clear opportunity to build on this momentum.
The challenge ahead is to ensure that the next generation of compound microchip technologies - developed in UK universities and labs - can grow and scale up here in the UK, rather than abroad.
Peter Gammon works as a Professor of Power Electronic Devices at the University of Warwick, and as the Founder of PGC Consultancy Ltd. At Warwick, he receives funding from UKRI, Horizon Europe and industrial partners. This work is supported via the Rewire Innovation and Knowledge Centre.
