Development of Silicon Carbide devices for next generation surge protection circuitry and power electronics

This project is focussed around novel semiconductor device design, fabrication and modelling and the scope can be expanded further; as there is interest in eventually making full SiC Integrated Circuits to provide revolutionary benefits such as operation at extremes of temperature and environment.
In terms of project aims, the Research Engineer will:
- Develop novel wide bandgap silicon carbide devices for application with the TBU.
- Create devices capable of being scaled up to industrial manufacturing. Working directly with R&D engineers at Bourns, Inc. to optimise the JFET device and gain valuable experience in a commercial fabrication environment.
- SiC ICs; potentially develop niche SiC semiconductor process technology through CISM to improve the performance of the controller chip itself.
- Investigate other promising wide bandgap materials such as Gallium Nitride MOSFETs and even Gallium Oxide FET devices to further lower cost.

Background
Bourns, Inc., is a global company with a strong Research and Development record in Power semiconductor devices and power electronics. For over seventy years, Bourns has been a leading global supplier of reliable high-quality electronic components and solutions, which have been designed into virtually every type of electronic system including automotive, telecommunications, computers and industrial applications.
The Bedford, UK branch of Bourns has an established reputation as a leading manufacturer of circuit protection semiconductors. They will soon be launching a new line of power semiconductor devices, a first generation of 650V IGBTs manufactured in the UK. These devices are ideally suited for electric vehicles, strategically placing Bourns as a future supplier in this rapidly expanding market.
The demand for high efficiency energy saving electronics to compliment low carbon technologies has already seen a market shift to silicon carbide as a semiconductor material, owing to its superior physical properties. A trend that is only going to accelerate in the future. Bourns is actively performing research in this area and will look to harness this material to compliment and expand its product portfolio.
The market for SiC power devices is set to grow exponentially - driven by the electric vehicles market. The timeliness of this project could not be any better given the UK government's announcement to ban all diesel, petrol and even hybrid vehicles by 2035 (see https://www.bbc.co.uk/news/science-environment-51366123). This is compounded by an additional wider, net zero carbon emissions target, by 2050.
The trend in terms of hybrid (HEV) / battery electric vehicle (BEV) powertrains is to push the DC voltage to beyond 600V, utilising high battery capacity systems. The purpose here is to reduce the demanding cabling requirements currently hampering electric vehicle performance. Beyond 600V, the only viable power semiconductor device option that can achieve the required efficiency levels is SiC. Power MOSFETs will be used within the main inverter powertrain, including a DC boost converter stage if required. Moreover, these higher voltage electric vehicle sales are set to reach 18 million by 2023, representing 16.2% of total global vehicle sales. The wider electrification becomes the more need for surge protection technologies.
JFET technology is today established in silicon carbide. The lack of a gate oxide makes it a desirable method to manufacture reliable switching devices. Although JFETs are commercially available they are not optimised for current limiting applications as utilised by the TBU. Control of threshold voltage and on-resistance of JFET devices is key to maintain low-loss in non-surge operation as well as agile control, turning off effectively when a surge appears.

The CDT will produce 50 graduates with doctoral level knowledge and research skills focussed on the development and manufacture of functional industrial coatings. Key impact areas are:

Knowledge
- The development of new products and processes to address real scientific challenges existing in industry and to transfer this knowledge into partnering companies. The CDT will enable rapid knowledge transfer between academia and industry due to the co-created projects and co-supervision.
- The creation of knowledge sharing network for partner companies created by the environment of the CDT.
- On average 2-3 publications per RE. Publications in high impact factor journals. The scientific scope of the CDT comprises a mixture of interdisciplinary areas and as such a breadth of knowledge can be generated through the CDT. Examples would include Photovoltaic coatings - Journal of Materials Chemistry A (IF 8.867) and Anti-corrosion Coatings - Corrosion Science (IF 5.245), Progress in Organic Coatings (IF 2.903)
- REs will disseminate knowledge at leading conferences e.g. Materials Research Society (MRS), Meetings of the Electrochemical Society, and through trade associations and Institutes representing the coatings sector.
- A bespoke training package on the formulation, function, use, degradation and end of life that will embed the latest research and will be available to industry partners for employees to attend as CPD and for other PGRs demonstrating added value from the CDT environment.

Wealth Creation
- Value added products and processes created through the CDT will generate benefits for Industrial partners and supply chains helping to build a productive nation.
- Employment of graduates into industry will transfer their knowledge and skills into businesses enabling innovation within these companies.
- Swansea University will support potential spin out companies where appropriate through its dedicated EU funded commercialisation project, Agor IP.

Environment and society
- Functionalised surfaces can potentially improve human health through anti-microbial surfaces for health care infrastructure and treatment of water using photocatalytic coatings.
- Functionalised energy generation coatings will contribute towards national strategies regarding clean and secure energy.
- Responsible research and innovation is an overarching theme of the CDT with materials sustainability, ethics, energy and end of life considered throughout the development of new coatings and processes. Thus, REs will be trained to approach all future problems with this mind set.
- Outreach is a critical element of the training programme (for example, a module delivered by the Ri on public engagement) and our REs will have skills that enable the dissemination of their knowledge to wide audiences thus generating interest in science and engineering and the benefits that investments can bring.

People
- Highly employable doctoral gradates with a holistic knowledge of functional coatings manufacture who can make an immediate impact in industry or academia.
- The REs will have transferable skills that are pertinent across multiple sectors.
- The CDT will develop ethically aware engineers with sustainability embed throughout their training
- The promotion of equality, diversity and inclusivity within our cohorts through CDT and University wide initiatives.
- The development of alumni networks to grow new opportunities for our CDT and provide REs with mentors.