Kean Boon Lee
Department of Electronic and Electrical Engineering
Senior Lecturer in GaN Electronic Devices
Semiconductor Materials and Devices Research Group
+44 114 222 5836
Full contact details
Department of Electronic and Electrical Engineering
I graduated from the Department (M.Eng 2004, Ph.D. 2010). After 2 years as a post-doctoral research associate working on gallium nitride (GaN) electronic devices for radio-frequency (RF) applications at the Department, I moved to Singapore and joined Institute of Microelectronics as a scientist.
I spent a year and a half at Singapore to develop next generation 600V high power GaN transistors for power conversion applications.
In 2013, I returned to this department and I am currently a lecturer in GaN Electronic Devices.
My main research interest is on GaN semiconductor material and devices for both optoelectronic and electronic applications.
Visible light emitting diodes (LEDs) found in solid-state light bulbs and TV screens are mainly made from GaN. In addition to visible light, GaN is also capable in emitting ultra- violet (UV) light efficiently which can be used in applications such as water purifications.
I have spent nearly 4 years in my PhD working in this area and our group has demonstrated the first GaN-based UV LEDs in the UK.
My current research focuses on utilising GaN in electronics applications including radio-frequency (such as amplifiers in 5G mobile communications and military radars) and high speed power conversion (such as 48V-1kV DC power supplies, inverters for photovoltaic systems).
I am particularly interested in employing novel integration techniques to achieve high efficiency GaN electronic devices and systems.
I am a member of committee of the UK Nitrides Consortium and program committee member for UK Semiconductor Conference.
- PhD in Electronic and Electrical Engineering, University of Sheffield, UK
- MEng in Electronic Engineering (Solid State Devices), University of Sheffield, UK
- Research interests
- High voltage and high current AlGaN/GaN-based transistors
- High speed/frequency RF GaN transistors
- High temperature operation of GaN-based transistors
- Monolithic integrations of GaN electronics
- Novel vertical high voltage (>600V) GaN transistors
- UV LEDs (wavelength: 250-350nm) design and device fabrication
- Fabrication of semi-polar (11-22) GaN V-groove MOSFET using wet etching trench opening technique. IEEE Electron Device Letters.
- High-performance enhancement-mode p-channel GaN MISFETs with steep subthreshold swing. IEEE Electron Device Letters, 43(4), 533-536.
- Vertical field inhomogeneity associated with threading dislocations in GaN high electron mobility transistor epitaxial stacks. Applied Physics Letters, 119(24).
- Dual metal gate AlGaN/GaN high electron mobility transistors with improved transconductance and reduced short channel effects. Journal of Physics D: Applied Physics, 54(10).
- A 624 V 5 A all‐GaN integrated cascode for power‐switching applications. physica status solidi (a), 217(7). View this article in WRRO
- Explore an approach towards the intrinsic limits of GaN electronics. ACS Applied Materials & Interfaces. View this article in WRRO
- Band alignments of sputtered dielectrics on GaN. Journal of Physics D: Applied Physics, 53(7), 075303-075303.
- Comparison of atomic layer deposited Al2O3 and (Ta2O5)0.12(Al2O3)0.88 gate dielectrics on the characteristics of GaN-capped AlGaN/GaN metal-oxide-semiconductor high electron mobility transistors. Journal of Applied Physics, 126(3). View this article in WRRO
- Analysis of gain variation with changing supply voltages in GaN HEMTs for envelope tracking power amplifiers. IEEE Transactions on Microwave Theory and Techniques, 67(7), 2495-2504. View this article in WRRO
- Lateral charge spreading and device-to-device coupling in C-doped AlGaN/GaN-on-Si wafers. Microelectronics Reliability, 95, 81-86. View this article in WRRO
- Field Plate Designs in All-GaN Cascode Heterojunction Field-Effect Transistors. IEEE Transactions on Electron Devices. View this article in WRRO
- Controllable uniform green light emitters enabled by circular HEMT-LED devices. IEEE Photonics Journal, 10(5). View this article in WRRO
- Vertical Leakage Mechanism in GaN on Si High Electron Mobility Transistor Buffer Layers. Journal of Applied Physics, 124(5). View this article in WRRO
- Effects of surface plasma treatment on threshold voltage hysteresis and instability in metal-insulator-semiconductor (MIS) AlGaN/GaN heterostructure HEMTs. Journal of Applied Physics, 123(18). View this article in WRRO
- The 2018 GaN power electronics roadmap. Journal of Physics D: Applied Physics, 51(16), 163001-163001. View this article in WRRO
- Nanoscale structural and chemical analysis of F-implanted enhancement-mode InAlN/GaN heterostructure field effect transistors. Journal of Applied Physics, 123. View this article in WRRO
- All-GaN-Integrated Cascode Heterojunction Field Effect Transistors. IEEE Transactions on Power Electronics, 32(11), 8743-8750. View this article in WRRO
- Novel GaN-based vertical heterostructure field effect transistor structures using crystallographic KOH etching and overgrowth. Journal of Crystal Growth, 459, 185-188. View this article in WRRO
- Characterization of p-GaN1-xAsx/n-GaN PN junction diodes. Semiconductor Science and Technology, 31(6). View this article in WRRO
- Subthreshold Mobility in AlGaN/GaN HEMTs. IEEE Transactions on Electron Devices, 63(5), 1861-1865.
- Control of threshold voltage in E-mode and D-mode GaN-on-Si metal-insulator-semiconductor heterostructure field effect transistors by in-situ fluorine doping of atomic layer deposition Al2O3 gate dielectrics. Applied Physics Letters, 108(7). View this article in WRRO
- Enhancement mode operation in AlInN/GaN (MIS)HEMTs on Si substrates using a fluorine implant. Semiconductor Science and Technology, 30(10), 105007-105007.
- Interface State Artefact in Long Gate-Length AlGaN/GaN HEMTs. IEEE Transactions on Electron Devices, 62(8), 2464-2469.
- Enhancement-mode metal–insulator–semiconductor GaN/AlInN/GaN heterostructure field-effect transistors on Si with a threshold voltage of +3.0 V and blocking voltage above 1000 V. Applied Physics Express, 8(3). View this article in WRRO
- Sulfuric acid and hydrogen peroxide surface passivation effects on AlGaN/GaN high electron mobility transistors. Journal of Applied Physics, 116(24), 244501-244501. View this article in WRRO
- Bi-layer SixNy passivation on AlGaN/GaN HEMTs to suppress current collapse and improve breakdown. SEMICOND SCI TECH, 25(12).
- Characterization of gate recessed GaN/AlGaN/GaN high electron mobility transistors fabricated using a SiCl4/SF6 dry etch recipe. J APPL PHYS, 108(1).
- Non-polar AlN and GaN/AlN on r-plane sapphire. Physica Status Solidi (C) Current Topics in Solid State Physics, 6(SUPPL. 2).
- Generation of misfit dislocations in highly mismatched GaN/AlN layers. SURF SCI, 602(15), 2643-2646.
- Temperature dependent behaviour of 340 nm light emitting diodes incorporating a gallium nitride interlayer. J PHYS D APPL PHYS, 41(9).
- The 310-340nm ultraviolet light emitting diodes grown using a thin GaN interlayer on a high temperature AlN buffer. J PHYS D APPL PHYS, 41(9).
- Two coexisting mechanisms of dislocation reduction in an AlGaN layer grown using a thin GaN interlayer. APPL PHYS LETT, 91(13).
- InGaN/GaN quantum wells with low growth temperature GaN cap layers. J CRYST GROWTH, 307(2), 363-366.
- Optical investigation of exciton localization in AlxGa1-xN. J APPL PHYS, 101(5).
- Greatly improved performance of 340 nm light emitting diodes using a very thin GaN interlayer on a high temperature AlN buffer layer. APPL PHYS LETT, 89(8).
- A study of dislocations in AIN and GaN films grown on sapphire substrates. J CRYST GROWTH, 282(3-4), 290-296.
Conference proceedings papers
- Device-to-device coupling via lateral conduction within the epitaxy in C-doped AlGaN/GaN-on-Si HEMTs. CS MANTECH 2018 - 2018 International Conference on Compound Semiconductor Manufacturing Technology
- Modelling the closely-coupled cascode switching process. 2016 IEEE Energy Conversion Congress and Exposition (ECCE), 18 September 2016 - 22 September 2016.
- Elimination of Leakage in GaN-on-Diamond. Technical Digest - IEEE Compound Semiconductor Integrated Circuit Symposium, CSIC, Vol. 2016-November View this article in WRRO
- Impact of buffer charge on the reliability of carbon doped AlGaN/GaN-on-Si HEMTs. IEEE International Reliability Physics Symposium Proceedings, Vol. 2016-September (pp 4A41-4A45) View this article in WRRO
- The origin of the high ideality factor in AlGaN-based quantum well ultraviolet light emitting diodes. PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS, Vol. 247(7) (pp 1761-1763)
- Effect of the AlGaN electron blocking layer thickness on the performance of AlGaN-based ultraviolet light-emitting diodes. JOURNAL OF CRYSTAL GROWTH, Vol. 311(10) (pp 2857-2859)
- Generation of Misfit Dislocations in Highly Mismatched GaN/AlN Layers. MICROSCOPY OF SEMICONDUCTING MATERIALS 2007, Vol. 120 (pp 33-36)
- Improved AIN buffer layer technologies for UV-LEDs. Physica Status Solidi C - Current Topics in Solid State Physics, Vol 4, No 1, Vol. 4(1) (pp 120-124)
- Teaching activities
- Lecturer in GaN Electronic Devices