"Semiconductors" are synonymous with "Silicon Chips". After all Silicon supported computing technologies in the 20th century. But Silicon is reaching fundamental limits and already many of the technologies we now take for granted are only possible because of Compound Semiconductors (CS). These include The Internet, Smart Phones, GPS and Energy efficient LED lighting! CSs are also at the heart of most of the new technologies expected in the next few years including 6G wireless, ultra-high speed optical fibre connectivity, LIDAR for autonomous vehicles, high voltage switching for electric vehicles, the IoT and high capacity data storage. CSs also offer huge opportunities for energy efficiency and net zero. CSs are often made in small quantities and using bespoke techniques and manufacturers have had to put together functions by assembling discrete devices. But this is expensive and for many of the new applications scale-up and integration, along the lines of the Silicon Chip, are needed CDT research will involve the science of large scale CS manufacturing, manufacturing integrated CS on Silicon and applying the manufacturing approaches of Silicon to CS; it will generate novel integrated functionality and all with an emphasis on finding environmentally sustainable manufacturing methods. CIVIC PRIORITY: This CDT is a fundamental part of the strategic development of the CS Cluster centred in South Wales, and in linking it to activity across the UK. It is part of a wider training strategy including apprenticeships, MScs and CPD, to train and upskill the entire workforce. The latest skills requirements have been identified by partner companies and through working with Welsh Government, CSconnected and the CS Applications Catapult The partners support the CDT financially and with their time. This is because the limiting factor to rapid cluster growth is skilled people. The expected PhD level jobs increase for the existing cluster companies alone would mop up all the students trained by this CDT. We provide a £2k stipend top-up to maximise recruitment from all backgrounds. However, the CDT does more - clusters are about cross-fertilisation of people and ideas and the CDT combines academics from 4 universities with leading and complementary expertise in CS. We form teams of two academics from different universities, one industry supervisor and the PhD student to create and carry out each PhD. The CDT also ensures the whole cohort regularly works together to exchange new knowledge and ideas and maintain breadth for each student. The UK and Welsh administrations see CS as an opportunity to boost the economy with high technology jobs and the UK government uses the CDT as part of its pitch to overseas companies to locate here. APPROACH and OUTCOMES: a 1+3 program where Year 1 (Y1) is based in Cardiff, with provision via taught lectures and transferable skills training, hands on and in-depth practical training and workshops led by University and Industry Partner staff. Following requests from Y2-4 students the industry workshops are presented in hybrid format so all Y2-4 students can further benefit from this program and where we now cycle presenters, companies and specific topics over 3 years. A dedicated training clean room allows rapid practical progress in a supportive environment, learning from doing, experts and the rest of the cohort and then an industry facing cleanroom, co-located with industry staff and manufacturing scale equipment, where students learn the future CS manufacturing skills. This maximises exchange of ideas, techniques and approach and the potential for exploitation. Both students and industry partners have praised the practical skills this produces. Y2-Y4 consist of an in depth PhD project, co-created with industry and hosted at one of the 4 universities, and specialised whole cohort training and events, including energy audit, research ethics and innovative outreach

"Semiconductors" are synonymous with "Silicon chips". After all Silicon supported computing technologies in the 20th century. But Silicon is reaching fundamental limits and already many of the technologies we take for granted are only possible because of Compound Semiconductors (CS). These include: the internet, smart phones and energy-efficient LED lighting! CSs are also at the heart of most of the new technologies envisaged, including 6G wireless, ultra-high speed optical fibre connectivity, LIDAR for autonomous vehicles, high voltage switching for electric vehicles, the IoT and high-capacity data storage. CSs also offer huge opportunities for energy efficiency and net zero. The CS Hub will contribute to "Engineering Net Zero", through products, such as energy-efficient electronics, and by introducing new environmentally-friendly manufacturing processes; to "Quantum Technologies", by creating practical implementations that can be manufactured at scale; to the "Physical and Mathematical Sciences Powerhouse" and "Frontiers in Engineering and Technology", through e.g. cutting-edge materials science and manufacturing-process innovation. CS materials are grown atom-by-atom on slices of crystalline material, known as substrates, which provide mechanical support for the resulting "wafer" during the next stage of fabrication. CSs are often made on relatively small substrates. Manufacturers have had to combine functions by assembling discrete devices but this is expensive. New approaches to integration in epitaxy and fabrication are required along with wafer-size scale-up for the new applications. Applications such as in quantum technology (QT) are pushing requirements for more accurate and highly reproducible manufacturing-processes. With such improvements CS will underpin the UK quantum industry and enable impact for the existing QT investments. We will create designs that are more tolerant to typical variations that occur during manufacturing; develop manufacturing processes that are more uniform and repeatable; create techniques to characterise performance part-way through manufacturing, create techniques to combine materials (e.g. CS grown atom-by-atom on Silicon) and combine functions on chip. We will study and implement ways to make CS manufacturing more environmentally friendly. We will make it easier to compare the environmental foot-print of different CS research and manufacturing-processes by making available relevant, high quality data in the form of accessible libraries of the resource and energy usage of the feedstocks and processes used in CS manufacturing. We aim to change the mind-set of UK academics. Our vision is that researchers think about the translation of their research from the beginning of the innovation process and about the requirements that next generation product manufacturers will face. As a critical factor in all future manufacturing, we aim to embed the philosophy of resource efficiency of the research itself, resource efficiency of the manufacturing process, as well as of the application it supports. We aim to repatriate and connect CS manufacturing supply chains to re-shore production and facilitate innovation, enabling development of holistic solutions. We will address the current staffing shortages of the CS industry by: providing leadership in improving career structure and enhancing training for Hub research and technical staff; putting in place the very best ED&I practice to create the most positive and inclusive working environment and promulgating this across the industry; inspiring the next generation of the CS workforce as well as spreading the news about the fantastic career opportunities currently available. By working closely with industry partners on all these aspects we will attract and retain staff in this critical UK manufacturing industry.