Silicon-Silicon Carbide (Si/SiC) Power Devices for high temperature, hostile environment applications
Lead Research Organisation:
University of Warwick
Department Name: Sch of Engineering
Abstract
Several problems facing society in the 21st century share a common problem: that when electronic devices heat up, they become inefficient, wasting energy. It is therefore the case that in your laptop there is significant space, weight and significant design cost associated with implementing the right cooling system to efficiently extract the heat. The laptop is however, a relatively low-power system, operating on earth at a rather pleasant 20C room temperature. Engineers are regularly facing this problem on a much larger scale, in much ambient temperatures, and in a situation where it is often difficult, expensive and often highly impractical to implement active cooling.
Oil and gas engineers, attempting to harvest the fossil fuels we are still highly dependent on, face exactly this problem with the electronics that are driving the cutting tool motor. Power electronic devices delivering hundreds of Watts of power to the motor must do so in an ambient that can exceed 225C, operating miles under the ground with only slurry pumped from the surface to cool the devices. Similarly, electric cars are forced into restrictive design choices keeping the electronics as far from the engine as possible to minimise the cooling requirements. In space, near-sun planetary explorers are essentially floating refrigerators, the inner cabin cooled, at great cost to eventual mission length, down to earth-like temperatures when the temperature outside can exceed 300C around Venus or Mercury. The potential benefit for having electronics operating in these environments without cooling is huge, leading to greater efficiency, reliability and mission length, saving space, weight and importantly cost.
This project looks to redesign the silicon device and to push its thermal behaviour to the absolute limit, so minimising the need for cooling, or eliminating it entirely. This is to be done by combining it with another material, silicon carbide, that will act as a heat sink placed within fractions of a micro-meter of the active device itself. These new Silicon-on-Silicon Carbide (Si/SiC) devices are expected to offer gains in device efficiency over any existing silicon device operating at elevated temperature. Alternatively, the same level of performance could be retained as with existing solutions, except at temperatures as much as 100C higher, or at much higher power (as much as 4x).
The power transistor, implemented entirely with the silicon thin film, is a laterally-diffused metal-oxide-semiconductor field effect transistor (LD-MOS) or a lateral insulated gate bipolar transistor (L-IGBT), similar to those that have been developed for silicon on insulator (SOI) or silicon-on-sapphire. These devices shall be optimised for breakdown voltages rated from 50 to 600 V, making the devices ideal for applications such as downhole motor drives required by project partner Halliburton, and for solar array inverters destined for space.
Oil and gas engineers, attempting to harvest the fossil fuels we are still highly dependent on, face exactly this problem with the electronics that are driving the cutting tool motor. Power electronic devices delivering hundreds of Watts of power to the motor must do so in an ambient that can exceed 225C, operating miles under the ground with only slurry pumped from the surface to cool the devices. Similarly, electric cars are forced into restrictive design choices keeping the electronics as far from the engine as possible to minimise the cooling requirements. In space, near-sun planetary explorers are essentially floating refrigerators, the inner cabin cooled, at great cost to eventual mission length, down to earth-like temperatures when the temperature outside can exceed 300C around Venus or Mercury. The potential benefit for having electronics operating in these environments without cooling is huge, leading to greater efficiency, reliability and mission length, saving space, weight and importantly cost.
This project looks to redesign the silicon device and to push its thermal behaviour to the absolute limit, so minimising the need for cooling, or eliminating it entirely. This is to be done by combining it with another material, silicon carbide, that will act as a heat sink placed within fractions of a micro-meter of the active device itself. These new Silicon-on-Silicon Carbide (Si/SiC) devices are expected to offer gains in device efficiency over any existing silicon device operating at elevated temperature. Alternatively, the same level of performance could be retained as with existing solutions, except at temperatures as much as 100C higher, or at much higher power (as much as 4x).
The power transistor, implemented entirely with the silicon thin film, is a laterally-diffused metal-oxide-semiconductor field effect transistor (LD-MOS) or a lateral insulated gate bipolar transistor (L-IGBT), similar to those that have been developed for silicon on insulator (SOI) or silicon-on-sapphire. These devices shall be optimised for breakdown voltages rated from 50 to 600 V, making the devices ideal for applications such as downhole motor drives required by project partner Halliburton, and for solar array inverters destined for space.
Planned Impact
The key deliverable from the proposed research project is a range of entirely new power electronic devices that can step silicon ever closer to the fundamental limits of its performance. The new devices will allow silicon-based converters to perform in much greater ambient temperatures, at higher power and/or with greater efficiency. As the project progresses, the appropriate exploitation of the results and the associated IP will lead to impact in a number of industrial sectors.
Engagement with industry during and after this project will be the key to delivering impact and eventually getting products to market that can generate profit within the UK. The downhole oil and gas industry is considered the primary target for this technology, given that the massive costs associated with subterranean exploration (off-shore drilling is often quoted as costing more than $1M per day [21]) mean that there is a constant drive for improved reliability to minimise downtime. Indeed, geopolitical events at the end of 2014 sent global oil prices tumbling, and as a result, the whole sector is seeking major efficiency savings. This has hit many UK based oil and gas companies and yet despite being directly affected by this, Halliburton have supported this research project, recognising the potential that can be delivered to their harsh environment electronics.
The space industry has the potential to be another major beneficiary from this technology. A report from NASA [17] outlined the need for electronics able to operate in temperatures up to 300C and beyond to 500C, which could lengthen the mission of near-sun planetary explorers (such as ESA's BepiColumbo or Venus Express), given the reduction in cooling requirements. Furthermore, a UK-based Space company have expressed an interest in this technology to transfer power between Earth and orbiting satellites.
UK company GE Aviation, who work very closely with the School of Engineering, have published details of their need for electronics at elevated temperatures, as they seek on-engine electronics capable of withstanding temperatures up to 250C. Furthermore, success in this project would undoubtedly lead to discussions with contacts in the automotive and power network companies, who could also benefit.
Impact will be delivered by the project for a number of people associated with this project also. The PI, Dr. Gammon, will benefit from the managerial experience as his research group expands to include a post-doctoral researcher. This post-doctoral researcher and the many students he supervises (3 PhD students, 1 MSc student by research, 1 MSC project student, 2 MEng project students and a summer undergraduate intern), will all benefit from increased exposure to the cutting-edge technologies and processes to be carried out on the project, from projects associated with the research, and from potential training opportunities at conferences or in-house.
Engagement with industry during and after this project will be the key to delivering impact and eventually getting products to market that can generate profit within the UK. The downhole oil and gas industry is considered the primary target for this technology, given that the massive costs associated with subterranean exploration (off-shore drilling is often quoted as costing more than $1M per day [21]) mean that there is a constant drive for improved reliability to minimise downtime. Indeed, geopolitical events at the end of 2014 sent global oil prices tumbling, and as a result, the whole sector is seeking major efficiency savings. This has hit many UK based oil and gas companies and yet despite being directly affected by this, Halliburton have supported this research project, recognising the potential that can be delivered to their harsh environment electronics.
The space industry has the potential to be another major beneficiary from this technology. A report from NASA [17] outlined the need for electronics able to operate in temperatures up to 300C and beyond to 500C, which could lengthen the mission of near-sun planetary explorers (such as ESA's BepiColumbo or Venus Express), given the reduction in cooling requirements. Furthermore, a UK-based Space company have expressed an interest in this technology to transfer power between Earth and orbiting satellites.
UK company GE Aviation, who work very closely with the School of Engineering, have published details of their need for electronics at elevated temperatures, as they seek on-engine electronics capable of withstanding temperatures up to 250C. Furthermore, success in this project would undoubtedly lead to discussions with contacts in the automotive and power network companies, who could also benefit.
Impact will be delivered by the project for a number of people associated with this project also. The PI, Dr. Gammon, will benefit from the managerial experience as his research group expands to include a post-doctoral researcher. This post-doctoral researcher and the many students he supervises (3 PhD students, 1 MSc student by research, 1 MSC project student, 2 MEng project students and a summer undergraduate intern), will all benefit from increased exposure to the cutting-edge technologies and processes to be carried out on the project, from projects associated with the research, and from potential training opportunities at conferences or in-house.
Organisations
- University of Warwick (Lead Research Organisation)
- CAMBRIDGE MICROELECTRONICS LTD (Collaboration)
- COVENTRY UNIVERSITY (Collaboration)
- University College Cork (Collaboration)
- Newcastle University (Collaboration)
- Thales Group (Collaboration)
- Université Catholique de Louvain (Collaboration)
- UNIVERSITY OF CAMBRIDGE (Collaboration)
- Halliburton KBR (Project Partner)
- Semelab (United Kingdom) (Project Partner)
People |
ORCID iD |
Peter Gammon (Principal Investigator) |
Publications
Chan C
(2017)
Comparative Study of RESURF Si/SiC LDMOSFETs for High-Temperature Applications Using TCAD Modeling
in IEEE Transactions on Electron Devices
Chan C
(2017)
Numerical Study of Energy Capability of Si/SiC LDMOSFETs
in Materials Science Forum
Chan C
(2016)
Si/SiC Substrates for the Implementation of Linear-Doped Power LDMOS Studied with Device Simulation
in Materials Science Forum
Chan C
(2016)
Analysis of Linear-Doped Si/SiC Power LDMOSFETs Based on Device Simulation
in IEEE Transactions on Electron Devices
Field D
(2022)
Thermal characterization of direct wafer bonded Si-on-SiC
in Applied Physics Letters
Gammon P
(2017)
Design and Fabrication of Silicon-on-Silicon-Carbide Substrates and Power Devices for Space Applications
in E3S Web of Conferences
Gammon P
(2017)
The Effect of Interfacial Charge on the Development of Wafer Bonded Silicon-on-Silicon-Carbide Power Devices
in Materials Science Forum
Gammon P
(2018)
Development, characterisation and simulation of wafer bonded Si-on-SiC substrates
in Materials Science in Semiconductor Processing
Woodend L
(2017)
Cryogenic Characterisation and Modelling of Commercial SiC MOSFETs
in Materials Science Forum
Description | The first ever Si/SiC power transistor, which could be used for space, downhole, or other harsh environment applications had been designed and fabricated. These 600V LDMOS and LIGBT devices balance the performance of a SiC substrate and a thin silicon 'device layer' so that it may better dissipate heat created when the device is in use. |
Exploitation Route | Having developed a new class of power semiconductor device, other research groups and industry will be able to use our findings to develop their own bespoke Si/SiC solutions. The knowledge developed is now being used in the development of radiation hard SiC power devices. |
Sectors | Aerospace Defence and Marine Electronics Energy |
URL | http://www2.warwick.ac.uk/pmgammon |
Description | Within this project we the very first Smart Cut Si-on-SiC materials system was developed, a material upon which we made radiation-hard power electronic devices that combined the mature processing of Si with some of the thermal properties of SiC. Over the last ten years, the rapid maturity of wide bandgap industries SiC and GaN have reduced the costs of these materials, making some of the advantages to our Si-on-SiC platform obsolete. Yet the lasting legacy of this project and the impact it will have, is what we as a group learnt about designing devices for a radiation-hard environment. These concepts, which include the device layout, the testing regimes, the packaging procedures, now underpin our new EPSRC grant (EP/V000543/1) in which we are optimising SiC power devices for space. With both ESA and Thales Alenia Space driving demand for these devices, the long lasting legacy will potentially be the first SiC power devices to be listed in ESA's approved flight list (ESCC). |
First Year Of Impact | 2017 |
Sector | Aerospace, Defence and Marine,Electronics,Energy |
Impact Types | Societal Economic |
Description | H2020 Competitiveness of the European Space Sector call (COMPET-03-2015: Bottom-up space technologies at low TRL) |
Amount | € 1,000,000 (EUR) |
Funding ID | 687361 |
Organisation | European Commission |
Sector | Public |
Country | European Union (EU) |
Start | 02/2016 |
End | 02/2018 |
Description | Silicon Carbide Power Conversion for Telecommunications Satellite Applications |
Amount | £746,426 (GBP) |
Funding ID | EP/V000543/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 03/2021 |
End | 03/2024 |
Description | Pre- proposal H2020 SaSHa Project collaboration |
Organisation | Cambridge Microelectronics Ltd |
Country | United Kingdom |
Sector | Private |
PI Contribution | The ideas formed in the EPSRC First Grant were used to form this collaboration. The work from this collaboration led to the H2020 application and project. Warwick' contribution was the background IP, the leadership of the project and the Development of the power devices in the cleanroom |
Collaborator Contribution | Tyndall National Institute - Materials science experts, formed the novel Si/SiC substrate. CMU - Device design experts - Laid out an doptiised the devices in simulation. UCL - Device/Radiation experts - teste devices for rad hardness in synchotron. TAS - Systems experts and end users. |
Impact | Three conference paper and a journal paper so far, work continuing. |
Start Year | 2015 |
Description | Pre- proposal H2020 SaSHa Project collaboration |
Organisation | Catholic University of Louvain |
Country | Belgium |
Sector | Academic/University |
PI Contribution | The ideas formed in the EPSRC First Grant were used to form this collaboration. The work from this collaboration led to the H2020 application and project. Warwick' contribution was the background IP, the leadership of the project and the Development of the power devices in the cleanroom |
Collaborator Contribution | Tyndall National Institute - Materials science experts, formed the novel Si/SiC substrate. CMU - Device design experts - Laid out an doptiised the devices in simulation. UCL - Device/Radiation experts - teste devices for rad hardness in synchotron. TAS - Systems experts and end users. |
Impact | Three conference paper and a journal paper so far, work continuing. |
Start Year | 2015 |
Description | Pre- proposal H2020 SaSHa Project collaboration |
Organisation | Thales Group |
Department | Thales Alenia Space |
Country | France |
Sector | Private |
PI Contribution | The ideas formed in the EPSRC First Grant were used to form this collaboration. The work from this collaboration led to the H2020 application and project. Warwick' contribution was the background IP, the leadership of the project and the Development of the power devices in the cleanroom |
Collaborator Contribution | Tyndall National Institute - Materials science experts, formed the novel Si/SiC substrate. CMU - Device design experts - Laid out an doptiised the devices in simulation. UCL - Device/Radiation experts - teste devices for rad hardness in synchotron. TAS - Systems experts and end users. |
Impact | Three conference paper and a journal paper so far, work continuing. |
Start Year | 2015 |
Description | Pre- proposal H2020 SaSHa Project collaboration |
Organisation | University College Cork |
Department | Tyndall National Institute |
Country | Ireland |
Sector | Academic/University |
PI Contribution | The ideas formed in the EPSRC First Grant were used to form this collaboration. The work from this collaboration led to the H2020 application and project. Warwick' contribution was the background IP, the leadership of the project and the Development of the power devices in the cleanroom |
Collaborator Contribution | Tyndall National Institute - Materials science experts, formed the novel Si/SiC substrate. CMU - Device design experts - Laid out an doptiised the devices in simulation. UCL - Device/Radiation experts - teste devices for rad hardness in synchotron. TAS - Systems experts and end users. |
Impact | Three conference paper and a journal paper so far, work continuing. |
Start Year | 2015 |
Description | Switch Optimisation Research Team |
Organisation | Coventry University |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | This is the research team that was put together for the Underpinning Power Electronics switch optimisation Theme. We are all working collaboratively, across the institutions towards the goals and objectivesof the research proposed. |
Collaborator Contribution | -- Cambridge and Coventry operate as the design house, they produce simulations that optimise the development of high voltage SiC power devices. -- Warwick and Newcastle are specialists in SiC power device development, and develop the devices in their cleanrooms. |
Impact | Research papers in preparation. |
Start Year | 2017 |
Description | Switch Optimisation Research Team |
Organisation | Newcastle University |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | This is the research team that was put together for the Underpinning Power Electronics switch optimisation Theme. We are all working collaboratively, across the institutions towards the goals and objectivesof the research proposed. |
Collaborator Contribution | -- Cambridge and Coventry operate as the design house, they produce simulations that optimise the development of high voltage SiC power devices. -- Warwick and Newcastle are specialists in SiC power device development, and develop the devices in their cleanrooms. |
Impact | Research papers in preparation. |
Start Year | 2017 |
Description | Switch Optimisation Research Team |
Organisation | University of Cambridge |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | This is the research team that was put together for the Underpinning Power Electronics switch optimisation Theme. We are all working collaboratively, across the institutions towards the goals and objectivesof the research proposed. |
Collaborator Contribution | -- Cambridge and Coventry operate as the design house, they produce simulations that optimise the development of high voltage SiC power devices. -- Warwick and Newcastle are specialists in SiC power device development, and develop the devices in their cleanrooms. |
Impact | Research papers in preparation. |
Start Year | 2017 |
Description | Talk to new conference beyond usual field (space - ESPC 2016) |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Invited to speak at ESPC 2016 (European Space Power Conference), which is a field beyond our usual expertise. This was based upoin the work carried out in the project. |
Year(s) Of Engagement Activity | 2016 |
URL | http://www.espc2016.com/ |