In a world increasingly dependent on semiconductor technology, from the smartphones in our pockets to advances in artificial intelligence (AI) and quantum computing, the demand for innovation in semiconductor manufacturing is higher than ever.
At the forefront of this shift is Professor David J. Lewis, Chair of Materials Chemistry at the University of Manchester, who has been pioneering research into additive manufacturing processes for semiconductors.
I attended a presentation where he shed light on the current state of the semiconductor industry, the UK’s strategic positioning, and the potential for novel manufacturing methods to revolutionise the sector.
The importance of semiconductors in modern life
Semiconductors are the backbone of modern technology, powering everything from communication devices to critical infrastructure. “The future of semiconductors lies in fields like quantum computing, AI, space exploration, and national defence,” Professor Lewis explained, highlighting the growing market and its key role in shaping the future. According to industry reports, the semiconductor market is expected to double between 2022 and 2030, driving demand across diverse sectors.
Yet, as technology advances, so too do the complexities and challenges surrounding semiconductor production. As Professor Lewis noted: “Semiconductors are not just a tool; they are the engine of progress, and their importance cannot be overstated.” The chips that power devices today – such as the smartphones that contain over eight billion transistors – are advancing rapidly. The miniaturisation of these components, governed by Moore’s Law, has led to chips with unprecedented power, such as the Intel Core i7, which now exhibits computing power comparable to a mouse brain.
The limits of traditional semiconductor manufacturing
Traditional semiconductor manufacturing has reached a critical juncture. The industry has long followed a three-step process: design, fabrication, and assembly. However, the cost and complexity of state-of-the-art fabrication (or fab) are immense. As Professor Lewis explained: “To produce cutting-edge silicon chips, you need a foundry, which can cost upwards of $18 billion. And the tools required – like the ASML extreme ultraviolet (EUV) lithography machine – are so large and energy-intensive that they’re not only expensive but also unsustainable.”
At the heart of this challenge is the limitation of current lithography methods, which, while effective, struggle to keep up with the shrinking size of transistors. The industry is pushing towards the 5-nanometer node, but the associated costs and physical constraints suggest that this may be as far as lithographic techniques can take us. “As you push the resolution smaller, the number of layers required to fabricate devices increases exponentially,” Professor Lewis explained. This makes it difficult, if not economically infeasible, to continue scaling down with traditional methods.
Geopolitical and supply chain vulnerabilities
Another critical issue is the geopolitically sensitive nature of semiconductor manufacturing. Taiwan dominates the global market, producing about 90% of the world’s advanced semiconductor chips. “The supply chains are incredibly complex,” Professor Lewis remarked, “and the UK, like many countries, is vulnerable to disruptions due to geopolitical events.” For example, the chip shortages experienced globally between 2020 and 2022 highlighted the risks inherent in such concentrated production. As semiconductor supply chains are increasingly difficult to trace, the UK is now focusing on strengthening its design capabilities and expertise in compound semiconductors, which are seen as a key area for innovation moving forward.
The role of the UK in semiconductor innovation
While the UK may be too far behind to re-enter the race of large-scale semiconductor fabrication, it is leveraging its strengths in design and intellectual property (IP). The success of companies like ARM, which designs chips used in billions of mobile devices worldwide, exemplifies the country’s strength in chip design. However, as Professor Lewis pointed out: “For the UK to remain competitive in the next generation of semiconductors, particularly at the seven-nanometer node, we need to innovate outside of traditional silicon.”
This is where additive manufacturing comes into play. Additive manufacturing – often referred to as 3D printing – has the potential to reshape semiconductor fabrication by building components layer by layer, rather than etching or chiselling them out of bulk material. This ‘bottom-up’ approach contrasts with the ‘subtractive’ methods used in traditional lithography, which can produce a significant amount of waste.
Additive manufacturing: a path forward
Professor Lewis and his team are exploring additive manufacturing for compound semiconductors – materials that go beyond silicon and offer promising properties for applications in areas like flexible electronics, lighting, and high-performance devices. One of the key advancements is the spin-on method, which involves applying a precursor material to a substrate and using thermal stress to form a compound semiconductor thin film. “We’ve made significant progress in developing low-energy, solvent-free processes to create high-purity compound semiconductor materials,” Professor Lewis said.
This approach is not only more sustainable but also more versatile. For instance, the team has successfully used spin-on techniques to produce thin films of semiconductors with electronic properties suitable for low-power applications. These include wearables, IoT devices, medical implants, and other low-power applications where high-speed performance is not critical. “Our work with spin-on technology demonstrates the potential to produce transistors with low leakage current, which is crucial for applications where power consumption must be minimised,” he noted.
Moreover, the integration of these spin-on materials into advanced device architectures – such as gate-all-around (GAA) transistors – could lead to breakthroughs in high-performance computing. This is particularly promising for neuromorphic computing, an emerging field inspired by the brain’s structure, which relies on devices like memristors to store and process information. “Memristors change their resistance based on voltage history, allowing them to store electrical information, making them ideal for neuromorphic applications,” Professor Lewis explained.
Looking to the future
The next step for Professor Lewis and his team is to scale up their work with the development of a £1.7 billion programme focused on direct writing of semiconductor nanostructures. “We’re making strides in creating high-resolution lines, and with continued improvements, we aim to push the boundaries of what’s possible in additive manufacturing for semiconductors,” he said.
The future of semiconductor manufacturing, according to Professor Lewis, lies in merging traditional and innovative methods. “We’re talking about an ‘atoms to devices’ approach, where we build semiconductors from the molecular level up. This opens up new avenues for manufacturing low-power, high-performance devices – paving the way for next-generation technologies like neuromorphic computing and advanced IoT systems.”
The UK’s semiconductor strategy will depend on its ability to harness these new manufacturing methods while securing its position in the global semiconductor ecosystem. By focusing on design, IP, and emerging technologies like compound semiconductors and additive manufacturing, the UK aims to remain at the forefront of semiconductor innovation – despite the challenges posed by geopolitics and industry limitations.
As the semiconductor industry faces rising challenges, the potential for innovation through additive manufacturing offers a beacon of hope. With researchers like Professor Lewis leading the charge, the future of semiconductors may well be built from the ground up – literally and figuratively.
