19 April 2021
UK’s SOCRATES project aims to establish supply chain for high-power SiC and GaN trench devices
The UK compound semiconductor sector is taking steps to establish an industrial supply chain for high-power silicon carbide (SiC) and gallium nitride (GaN) trench devices.
SOCRATES (SilicOn Carbide tRAansistor Trench procEsS) is a 9-month project (from January-September) that is part funded by £137,423 from the Catalysing Green Innovation challenge of government agency Innovate UK via UK Research and Innovation (UKRI). The objective of the project is to address opportunities in the UK power electronics, machines and drives (PEMD) supply chain.
PEMD supply chains play a critical role in the global decarbonization effort and in achieving net zero targets. Applications require robust devices that can operate at high voltages, temperatures and frequencies, as well as the ability to handle high current densities. Wide-bandgap (WBG) semiconductor materials are suited to such applications and allow for an increase in system efficiencies and reduction in weight and volume.
The compound semiconductor materials silicon carbide (SiC) and gallium nitride on silicon carbide (GaN-on-SiC) are frontrunners in the field of high-power devices and are identified as optimal WBG materials for trench-based vertical devices to increase device performance.
The SOCRATES project addresses gaps in the PEMD UK supply chain, i.e. the lack of (1) a trench SiC power MOSFET process and (2) a high-volume supplier of SiC transistors for the UK EV industry, with no existing UK-based high-volume 6-8” SiC wafer fabs. In contrast, international competitors are establishing key strategic PEMD links in order to supply SiC devices to the future EV market, e.g. Infineon with Hyundai, STMicroelectronics (already producing 4000 wafers per month) with Tesla, and XFab with General Motors and Ford. Thus, the UK is in danger of losing its security of supply of this crucial technology to the UK automotive sector, it is reckoned.
Led by SPTS Technologies Ltd of Newport, Wales, UK – a KLA company that manufactures etch, deposition and thermal wafer processing solutions – the consortium also includes Newport Wafer Fab (NWF, the UK’s 200mm compound semiconductor wafer foundry), Swansea University, Compound Semiconductor Centre Ltd (CSC, a joint venture founded in 2015 between Cardiff University and epiwafer foundry and substrate maker IQE plc of Cardiff, Wales) and CSconnected (the compound semiconductor cluster, based in South Wales). The consortium aims to deliver industrial processes for SiC and GaN-on-SiC trench etching, as well as in-line fabrication processes for integration of the etch into high-volume manufacturing.
“Whilst the UK has strong industrial expertise in PEMD systems development, there has been a lack of a coordinated PEMD supply chain in the UK until now, with high-volume supply of vertical SiC transistors being identified as an opportunity gap, particularly for the growing electric vehicle (EV) industry,” comments Rob Harper, program manager Power & RF at CSC.
“As a UK-based global company in the semiconductor industry we have a strong customer base overseas and we look forward to supporting the UK activity in the decarbonization effort through regional collaboration,” states Huma Ashraf, process technology manager at SPTS. “As we have seen with silicon in the past, SiC and GaN are moving towards vertical, trench-based structures and SPTS’s wafer processing solutions and extensive experience in compound semiconductors are well-suited to deliver this at an industrial scale,” he believes.
In addition to the capabilities at SPTS in etch technologies, the project also benefits from years of know-how in power device fabrication at Newport Wafer Fab (the UK’s largest semiconductor fabrication facility). “The power semiconductor device market is going from strength to strength, with EVs, renewables and wider electrification efforts paving the way for rapid growth in demand for SiC devices,” comments Sam Evans, NWF’s director of quality & external affairs.
“Here at Swansea University, we have invested heavily in 6”and 8” fabrication facilities and expertise to support the semiconductor industry with prototyping activities,” notes Swansea University associate professor Mike Jennings. “These industry-focused projects are invaluable in training future talent for the growing compound semiconductor industry,” he adds.
“PEMD is a perfect example of the many applications in which compound semiconductors are set to become ubiquitous with the increasing demand for high-performance devices, from power and energy through to communications and quantum technologies,” states CSconnected director Chris Meadows. “The CSconnected cluster has a long history in collaborative R&D in compound semiconductor technologies and is positioned strongly to deliver on future cutting-edge, high-volume opportunities.”
CSC and NWF to develop 200mm GaN HEMT foundry process
SPTS Newport Wafer Fab CSC CSConnected