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Professor Alton Horsfall's Outputs (20)

Dual polarity multi-level boost DC-DC converter (2024)
Presentation / Conference Contribution
Blackhorse-Hull, D., Mohanan-Leela, P., Alsafrani, A., Sarma, N., Crabtree, C., & Horsfall, A. (2024, June). Dual polarity multi-level boost DC-DC converter. Presented at 13th International Conference on Power Electronics, Machines and Drives (PEMD 2024), Nottingham, UK

Increased Mobility in 4H-SiC MOSFETs by Means of Hydrogen Annealing (2022)
Journal Article
Idris, M. I., & Horsfall, A. (2022). Increased Mobility in 4H-SiC MOSFETs by Means of Hydrogen Annealing. Crystals, 12(8), Article 1111. https://doi.org/10.3390/cryst12081111

Enhancement-mode 4H-SiC MOSFETs utilising an aluminium oxide (Al2O3) dielectric without the requirement for an underlying silicon oxide (SiO2) layer have been shown to have a field effect mobility of 150 cm2V−1s−1 and a subthreshold swing of 160 mV/d... Read More about Increased Mobility in 4H-SiC MOSFETs by Means of Hydrogen Annealing.

Single event burnout sensitivity of SiC and Si (2022)
Journal Article
Littlefair, M. T. M., Simdyankin, S., Turvey, S., Groves, C., & Horsfall, A. B. (2022). Single event burnout sensitivity of SiC and Si. Semiconductor Science and Technology, 37(6), Article 065013. https://doi.org/10.1088/1361-6641/ac668c

Exposure to ionizing radiation has the potential to catastrophically modify the operation, and destroy, electronic components in microseconds. The electrification of aircraft necessitates the need to use the most power dense and lowest loss semicondu... Read More about Single event burnout sensitivity of SiC and Si.

3D structures for silicon carbide transistors utilising Al2O3 as a gate dielectric (2021)
Journal Article
Idris, M. I., & Horsfall, A. B. (2021). 3D structures for silicon carbide transistors utilising Al2O3 as a gate dielectric. Materials Science in Semiconductor Processing, 128, https://doi.org/10.1016/j.mssp.2021.105727

This paper reports on the first investigation of the characteristics of 3D structures formed in silicon carbide for the realisation of ultra-high performance nanoscale transistors, based on the FINFET topology. Capacitance–voltage characteristics sho... Read More about 3D structures for silicon carbide transistors utilising Al2O3 as a gate dielectric.

Modelling the Key Material Properties of Germanium for Device Simulation in Cryogenic Environments (2020)
Journal Article
Bradley, L., Horsfall, A., & Dyson, A. (2020). Modelling the Key Material Properties of Germanium for Device Simulation in Cryogenic Environments. IEEE Transactions on Electron Devices, 67(10), 4099-4104. https://doi.org/10.1109/ted.2020.3018097

Germanium is commonly suggested as an alternative for power electronic devices in emerging liquid hydrogen applications. Despite the clear benefits of a twofold conductivity increase and fabrication familiarity within the community, very few models e... Read More about Modelling the Key Material Properties of Germanium for Device Simulation in Cryogenic Environments.

First Principles Study of the Stability and Diffusion Mechanism of a Carbon Vacancy in the Vicinity of a SiO2/4H‐SiC Interface (2019)
Journal Article
Alsnani, H., Goss, J., Briddon, P., Rayson, M., & Horsfall, A. (2019). First Principles Study of the Stability and Diffusion Mechanism of a Carbon Vacancy in the Vicinity of a SiO2/4H‐SiC Interface. physica status solidi (a) – applications and materials science, 216(17), Article 1900328. https://doi.org/10.1002/pssa.201900328

We have studied the carbon vacancy in bulk 4H‐SiC and in the vicinity of an SiO /(0001)‐4H‐SiC interface using density functional theory. We find that migration is hindered in the immediate vicinity of the interface, with the energy barrier for diffu... Read More about First Principles Study of the Stability and Diffusion Mechanism of a Carbon Vacancy in the Vicinity of a SiO2/4H‐SiC Interface.

Pore Wall Thinning of Mesoporous 4H-SiC by Sacrificial Oxidation (2018)
Journal Article
Rashid, M., Idris, M. I., Horrocks, B. R., Healy, N., Goss, J. P., & Horsfall, A. B. (2018). Pore Wall Thinning of Mesoporous 4H-SiC by Sacrificial Oxidation. Crystal Research and Technology, 53(9), Article 1800120. https://doi.org/10.1002/crat.201800120

Pore wall thinning of mesoporous 4H‐SiC by sacrificial oxidation is performed. The dimensions within the as‐etched porous SiC are reduced during dry oxidation at 1100 °C by consuming SiC and removing the grown SiO2 in the subsequent hydrofluoric acid... Read More about Pore Wall Thinning of Mesoporous 4H-SiC by Sacrificial Oxidation.

Silicon Carbide Oscillators for Extreme Environments (2018)
Book Chapter
Brennan, D., Chan, H., Wright, N., & Horsfall, A. (2018). Silicon Carbide Oscillators for Extreme Environments. In S. Walia, & K. Iniewski (Eds.), Low power semiconductor devices and processes for emerging applications in communications, computing, and sensing (225-252). CRC Press. https://doi.org/10.1201/9780429503634-10

This chapter provides an overview of a range of oscillator circuit topologies that are compatible with analog circuits designs and hence existing silicon carbide technology, before focusing on the realization of a high-temperature Colpitts oscillator... Read More about Silicon Carbide Oscillators for Extreme Environments.

Surface Functionalisation of Silicon Carbide Quantum Dots (2018)
Book Chapter
Rashid, M., Horrocks, B., Healy, N., Goss, J., Chan, H., & Horsfall, A. (2018). Surface Functionalisation of Silicon Carbide Quantum Dots. In S. Walia, & K. Iniewski (Eds.), Low Power Semiconductor Devices and Processes for Emerging Applications in Communications, Computing and Sensing (181-199). CRC Press. https://doi.org/10.1201/9780429503634-8

Silicon carbide (SiC) nanostructures are appealing as non-toxic, water-stable and oxidation-resistant nanomaterials. Owing to these unique properties, three-dimensionally confined SiC nanostructures, namely SiC quantum dots (QDs), have found applicat... Read More about Surface Functionalisation of Silicon Carbide Quantum Dots.

Self-Oscillatory DC-DC Converter Circuits for Energy Harvesting in Extreme Environments (2018)
Book Chapter
Weng, M., Brennan, D., Wright, N., & Horsfall, A. (2018). Self-Oscillatory DC-DC Converter Circuits for Energy Harvesting in Extreme Environments. In M. Niu (Ed.), Advanced electronic circuits (3-20). IntechOpen. https://doi.org/10.5772/intechopen.72718

A novel self-starting converter circuit technology is described for energy harvesting and powering wireless sensor nodes, constructed from silicon carbide devices and proprietary high temperature passives for deployment in hostile environments. After... Read More about Self-Oscillatory DC-DC Converter Circuits for Energy Harvesting in Extreme Environments.

First Demonstration of High Temperature SiC CMOS Gate Driver in Bridge Leg for Hybrid Power Module Application (2018)
Journal Article
Weng, M., Idris, M., Wright, S., Clark, D., Young, R., McIntosh, J., Gordon, D., & Horsfall, A. (2018). First Demonstration of High Temperature SiC CMOS Gate Driver in Bridge Leg for Hybrid Power Module Application. Materials Science Forum, 924, 854-857. https://doi.org/10.4028/www.scientific.net/msf.924.854

A high-temperature silicon carbide power module using CMOS gate drive technology and discrete power devices is presented. The power module was aged at 200V and 300 °C for 3,000 hours in a long-term reliability test. After the initial increase, the va... Read More about First Demonstration of High Temperature SiC CMOS Gate Driver in Bridge Leg for Hybrid Power Module Application.

Analysis of 3-Dimensional 4H-SiC MOS Capacitors Grown by Atomic Layer Deposition of Al2O3 (2018)
Journal Article
Idris, M., Wright, N., & Horsfall, A. (2018). Analysis of 3-Dimensional 4H-SiC MOS Capacitors Grown by Atomic Layer Deposition of Al2O3. Materials Science Forum, 924, 490-493. https://doi.org/10.4028/www.scientific.net/msf.924.490

3-Dimensional 4H-SiC metal-oxide-semiconductor capacitors have been fabricated to determine the effect of the sidewall on the characteristics of 3-Dimentional gate structures. Al2O3 deposited by Atomic Layer Deposition (ALD) was used as the gate diel... Read More about Analysis of 3-Dimensional 4H-SiC MOS Capacitors Grown by Atomic Layer Deposition of Al2O3.

Effect off Post Oxide Annealing on the electrical and Interface 4-H SiC/Al2O3 MOS Capacitors (2018)
Journal Article
Idris, M., Wright, N., & Horsfall, A. (2018). Effect off Post Oxide Annealing on the electrical and Interface 4-H SiC/Al2O3 MOS Capacitors. Materials Science Forum, 924, 486-489. https://doi.org/10.4028/www.scientific.net/msf.924.486

This paper reports on the effect of forming gas annealing on the C-V characteristics and stability of Al2O3/SiC MOS capacitors deposited by atomic layer deposition, (ALD). C-V and I-V measurements were performed to assess the quality of the Al2O3 lay... Read More about Effect off Post Oxide Annealing on the electrical and Interface 4-H SiC/Al2O3 MOS Capacitors.

Recent advance in high manufacturing readiness level and high temperature CMOS mixed-signal integrated circuits on silicon carbide (2017)
Journal Article
Weng, M., Clark, D., Wright, S., Gordon, D., Duncan, M., Kirkham, S., Idris, M., Chan, H., Young, R., Ramsay, E., Wright, N., & Horsfall, A. (2017). Recent advance in high manufacturing readiness level and high temperature CMOS mixed-signal integrated circuits on silicon carbide. Semiconductor Science and Technology, 32(5), Article 054003. https://doi.org/10.1088/1361-6641/aa61de

A high manufacturing readiness level silicon carbide (SiC) CMOS technology is presented. The unique process flow enables the monolithic integration of pMOS and nMOS transistors with passive circuit elements capable of operation at temperatures of 300... Read More about Recent advance in high manufacturing readiness level and high temperature CMOS mixed-signal integrated circuits on silicon carbide.

Instability of phosphorous doped SiO2 in 4H-SiC MOS capacitors at high temperatures (2016)
Journal Article
Idris, M., Weng, M., Chan, H., Murphy, A., Clark, D., Young, R., Ramsay, E., Wright, N., & Horsfall, A. (2016). Instability of phosphorous doped SiO2 in 4H-SiC MOS capacitors at high temperatures. Journal of Applied Physics, 120(21), Article 214902. https://doi.org/10.1063/1.4969050

In this paper, the effect of inclusion of phosphorous (at a concentration below 1%) on the high temperature characteristics (up to 300 °C) of the SiO2/SiC interface is investigated. Capacitance–voltage measurements taken for a range of frequencies ha... Read More about Instability of phosphorous doped SiO2 in 4H-SiC MOS capacitors at high temperatures.

Optical properties of mesoporous 4H-SiC prepared by anodic electrochemical etching (2016)
Journal Article
Rashid, M., Horrocks, B., Healy, N., Goss, J., & Horsfall, A. (2016). Optical properties of mesoporous 4H-SiC prepared by anodic electrochemical etching. Journal of Applied Physics, 120(19), Article 194303. https://doi.org/10.1063/1.4968172

Porous silicon carbide was fabricated from n-type 4H-SiC substrates via anodic electrochemical etching in HF/ethanol solution and suspended in ethanol after ultrasonication. We observed three photoluminescence bands: two at wavelengths of 303 nm and... Read More about Optical properties of mesoporous 4H-SiC prepared by anodic electrochemical etching.

Assignment of 13C hyperfine interactions in the P1-center in diamond (2016)
Journal Article
Peaker, C., Atumi, M., Goss, J., Briddon, P., Horsfall, A., Rayson, M., & Jones, R. (2016). Assignment of 13C hyperfine interactions in the P1-center in diamond. Diamond and Related Materials, 70, 118-123. https://doi.org/10.1016/j.diamond.2016.10.013

Diamond is an attractive material due to its extreme physical properties, and has recently found a key role in the developing field of quantum bits based upon long spin coherence times at room temperature. In both natural and synthetic diamond, nitro... Read More about Assignment of 13C hyperfine interactions in the P1-center in diamond.

Surface-state dependent optical properties of OH-, F-, and H-terminated 4H-SiC quantum dots (2016)
Journal Article
Rashid, M., Tiwari, A. K., Goss, J., Rayson, M., Briddon, P., & Horsfall, A. (2016). Surface-state dependent optical properties of OH-, F-, and H-terminated 4H-SiC quantum dots. Physical Chemistry Chemical Physics, 18(31), Article 21676. https://doi.org/10.1039/c6cp03775e

Density functional calculations are performed for OH-, F- and H-terminated 4H-SiC 10–20 Å diameter clusters to investigate the effect of surface species upon the optical absorption properties. H-termination results in a pronounced size-dependent quan... Read More about Surface-state dependent optical properties of OH-, F-, and H-terminated 4H-SiC quantum dots.

Determination of the adhesion energy of graphene on SiC(0001) via measurement of pleat defects (2014)
Journal Article
Wells, G., Hopf, T., Vassilevski, K., Escobedo-Cousin, E., Wright, N., Horsfall, A., …Hunt, M. (2014). Determination of the adhesion energy of graphene on SiC(0001) via measurement of pleat defects. Applied Physics Letters, 105(19), Article 193109. https://doi.org/10.1063/1.4901941

Pleat defects in graphene grown on SiC(0001) were studied and used to determine the adhesion energy between few-layer graphene (3 ± 1 monolayers) and the substrate. An adhesion energy of 3.0±1.61.0J/m2 was determined using a continuum model describin... Read More about Determination of the adhesion energy of graphene on SiC(0001) via measurement of pleat defects.