Over the past 50 years, society has benefitted from electronic devices getting smaller and smaller. The challenge of making such small devices has meant that the processes have increased dramatically in cost, to the extent that the latest 'printer' of very small features costs up to $100M. Only a small number of high-volume products can sustain such a cost. Nevertheless, new physics can occur, and materials can have novel properties at the smallest scales - the nanoscale. So, for society to use these more widely, we need to develop cheaper ways of making small materials and devices. Otherwise, they are unviable, and research into the opportunities that they provide will be limited. This proposal is about extending a recently developed technique called Displacement Talbot Lithography that uses the interference of light to make very small patterns. We will then combine it with other processes, such as atomic layer deposition that allows materials to be controllably coated with individual layers of atoms, to further decrease the pattern size. The technique is exciting because it combines low-cost with high yield and can be scaled relatively easily to large areas, to further increase manufacturability; important for them to be produced at the scale to be used in society at large. Being a new technique, its potential is still relatively unknown. We will then apply the patterning technique to the manufacture of advanced materials that can combine conventional electronics based on silicon with optical communications. Whilst silicon is a mature material for making electronics, it manages light poorly. By growing crystals of good optical materials such as indium phosphide directly on silicon we will combine the optimum properties of both materials to make an engineered super-material. But this can only be done cost-effectively by using the very fine patterning that is possible with Displacement Talbot Lithography. To achieve these goals, the University of Bath and Cardiff University are combining their expertise and working together. Researchers at Bath are experts in large area nanofabrication whilst those at Cardiff are experts in growing group III-V semiconductor crystals for use in optical communications. We will also be partnering with UK manufacturing industry who have the interest and ability to exploit the results and have the wider industry connections to pass on the benefits up the supply chain: Newport Wafer Fab is an advanced semiconductor processing facility that currently boasts International Rectifier, Motorola, Samsung, STM as its clients, whilst PragmatIC Semiconductor is a world leader in ultra-low-cost flexible electronics.

The history of II-VI metal-organic chemical vapour deposition (MOCVD) goes back as far as IIII-V MOCVD but has not had the traction in applications for lasers, LEDs and high frequency devices that has been experienced by III-V semiconductors. A new generation of MOCVD equipment can more fully exploit the potential of II-VI semiconductors and explore new oxides and chalcogenides in the exiting areas of III-VIs such as Ga2O3 and 2-D semiconductors such as MoS2. There is now a compelling case for the UK to have state-of-the-art MOCVD equipment for compound semiconductors (CS) covering oxide and chalcogenide materials that are not covered by existing centres such as the National Epitaxy Facility at Sheffield, Cambridge and UCL, and Institute of CS at Cardiff. The UK has a golden opportunity to build on our strengths in CS research that will drive innovation across a range of new opto-electronic and power electronic devices. The need arises from a new generation of functional compound semiconductor materials to capture the unique properties of oxide and chalcogenide compound semiconductors (CSs), complementing III-V compounds and silicon, and opening new application areas in optoelectronics, energy and healthcare. It is proposed that we buy the Aixtron Close Couple Showerhead (CCS) reactor that has been proven to be the reactor design of choice for GaN deposition and will be the ideal equipment to deposit high quality oxide and chalcogenide compound semiconductor materials. "The UK needs this facility, which it does not have at present. Swansea is an excellent place for it." - Prof. Sir Colin Humphreys (Cambridge). "This proposed research facility will perfectly complement the installation of ~100 production MOCVD reactors leveraged by a £375M investment by IQE Plc over 2018-2022" - Dr Wyn Meredith (CSC, Cardiff). The CCS reactor will be installed in a new building for the Centre for Integrated Semiconductor Materials (CISM) (due for completion in Q1 2021) on the Swansea University Bay Campus. Over 140 m2 of specialist materials laboratory space will be allocated to the MOCVD reactor and complementary materials and characterisation equipment from Professor Irvine's laboratory. This new laboratory will be managed by Professor Irvine's team to provide high quality oxide and chalcogenide CSs to our research partners in Swansea University, other UK universities, industrial partners and to international collaborators. This will put the UK at the forefront of new science and technology using oxide and chalcogenide CSs for applications including high efficiency photovoltaic solar cells, Light harvesting quantum wire opto-electronic devices, piezoelectric energy harvesting, high breakdown voltage power electronic devices and light emitters. This new science and technology will benefit EPSRC priorities of "21st Century Products" and "Sustainable Industries" through enabling smart new products that could be rapidly prototyped through well proven manufacturing capability for MOCVD in the UK and enabling the application of more sustainable materials and reduced materials usage. This exciting opportunity is detailed in the case for support.

We are living in an increasingly digitalised world where data has become critical to all aspects of human life. Today's data centres are consuming about 3 percent of the global electricity supply and this number is likely to triple in the next decade. Remarkably, more than 50% of the power consumption in high-performance computing and data centres is associated with moving information around, rather than processing it. The current COVID-19 pandemic highlights the importance of healthcare monitoring and remote working using high speed broadband connections. Optical communications is essential to accommodate the need for high speed and bandwidth, while at the same time reducing the power required. In the meantime, 3D imaging and sensing is pushing the next revolution in consumer electronics by facilitating artificial intelligence (AI)-powered devices. LiDAR, or Light Detection and Ranging, is one of the key technologies enabling this market growth with anticipated market share reaching $6 billion by 2024, 70% of which dedicated to automotive applications. From telecommunications to sensing applications, photons have proven to be the most efficient platform. As optical communication is penetrating to shorter and shorter distances and the 3D imaging and sensing expanding across the consumer, automotive, medical and industry/commercial sectors, the photonics manufacturing industry is on the verge of technological advancements. However, high cost, low volume capacity and limited scalability of the photon-based platform has become the bottleneck hindering cutting-edge technologies entering mass production. In this regard, integrating bulky, expensive optical components (the lasers, modulators, amplifiers, detectors and lenses) onto a much affordable and scalable platform like silicon is being much sought after by major industry and academic groups. Over the last six decades, silicon has driven the production of new technologies based on electrons at ever astounding volumes. Looking ahead, the silicon platform can be leveraged as a means to overcome the scalability, manufacturing and system architecture challenges experienced by photonics industry, impacting a range of emerging markets where small form factor, low-cost manufacturing and power efficiency are figures of merit. In this project, we aim to integrate high-performance lasers and amplifiers operating at the strategically important C-band at 1550 nm onto the scalable silicon platform. These devices are one of the most critical components enabling long-haul optical fibre communications, inter-data centre optical interconnect and emerging 3D imaging and sensing technologies including eye-safe LiDAR chips. Leveraging the complementary growth techniques of molecular beam epitaxy (MBE) and metal organic chemical vapour deposition (MOCVD), we will incorporate manufacturable nanostructures as the gain medium to realise advanced devices surpassing state-of-the-art. Several routes will be explored to overcome the challenges in growing these materials and devices onto silicon towards fully integrated photonic platforms, opening up the opportunity for low cost and high volume mass production.

The sensing, processing and transport of information is at the heart of modern life, as can be seen from the ubiquity of smart-phone usage on any street. From our interactions with the people who design, build and use the systems that make this possible, we have created a programme to make possible the first data interconnects, switches and sensors that use lasers monolithically integrated on silicon, offering the potential to transform Information and Communication Technology (ICT) by changing fundamentally the way in which data is sensed, transferred between and processed on silicon chips. The work builds on our demonstration of the first successful telecommunications wavelength lasers directly integrated on silicon substrates. The QUDOS Programme will enable the monolithic integration of all required optical functions on silicon and will have a similar transformative effect on ICT to that which the creation of silicon integrated electronic circuits had on electronics. This will come about through removing the need to assemble individual components, enabling vastly increased scale and functionality at greatly reduced cost.

TOPIC: "Semiconductors" are often 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 technologies 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 5G wireless, ultra-high speed optical fibre connectivity, LIDAR for autonomous vehicles, high voltage switching for electric vehicles, the IoT and high capacity data storage. To date CSs are made in relatively small quantities using fairly bespoke manufacturing and manufacturers have had to put together functions by assembling discrete devices. But this is expensive and for many of the new applications integration is needed along the lines of the Silicon Integrated Chip. CDT research will involve: the science of large scale CS manufacturing (e.g. materials combinations to minimise wafer bow, new fabrication processes for non-flat surfaces); manufacturing integrated CS on Silicon and in applying the manufacturing approaches of Silicon to CS. The latter includes using generic processes and generic building blocks and applying statistical process control. By applying these approaches students will address and invent new ways to exploit the highly advantageous electronic, magnetic, optical and power handling properties of CSs and generate novel integrated functionality for sensing, data processing and communication. NEED: This CDT is a critical part of the strategic development of a CS Cluster supporting activity throughout the UK. It is part of the development of a wider training portfolio including apprenticeships and CPD activities, to train and upskill the CS workforce. Evidence of the critical need for a CDT, has been identified in a survey and analysis conducted by UK Electronics Skills Foundation highlighting the specific skills required in this rapidly growing high technology industrial sector. "We are looking for PhD level skills plus industry experience. We don't have the time to train up new staff." "There are no 'perfect employees' for CS companies, as this is effectively a new area. Staff, including those with PhDs, either have silicon skills and need CS-specific training, or have CS skills and need training in volume tools and processes, either in the cleanroom or in packaging." - quotes from CS Skills Survey - Report UKESF July 2018. We have worked with the CSA Catapult utilising the skills need they have identified as well as companies across the spectrum of CS activities and are confident of the absorptive capacity: the expected PhD level jobs increase for the existing cluster companies alone would employ all the students and the CDT will support many more companies and academic institutions. APPROACH: a 1+3 programme where Year 1 is based in Cardiff, with provision via taught lectures using university approved level 7 modules and transferable skills training, hands on and in-depth practical training and workshop material supplied by University and Industry Partner staff. A dedicated nursery clean room to allow rapid practical progress, learning from peer group activity and then an industry facing environment with co-location with industry staff and manufacturing scale equipment, where they will learn the future CS manufacturing skills. This will maximise cross fertilisation of ideas, techniques and approach and maximise the potential for exploitation. 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 communication, responsible innovation, entrepreneurship, co-innovation techniques and innovative outreach.