Kei May LAU (PhD, Rice University, 1981)

Chair Professor

E-mail "eekmlau@ust.hk"

Research Interests

High Frequency, high speed and photonic devices: Light Emitting Diodes (LEDs), Heterostructure field-effect and bipolar transistors (HFETs and HBTs); Metalorganic chemical vapor deposition (MOCVD) of compound semiconductors including III-nitrides, III-As/P/Sb and dilute nitride alloys, nano-structures, selective-area hetero-epitaxy; material and device characterization.

Professor Kei May Lau was born in Hong Kong and received all her pre-college education from the Pui Ching Middle School (K-12). She received the B.S. and M.S. degrees in physics from University of Minnesota , Minneapolis , in 1976 and 1977 respectively, and the Ph.D. Degree in Electrical Engineering from Rice University , Houston , Texas , in 1981.

From 1980 to 1982, she was a Senior Engineer at M/A-COM Gallium Arsenide Products, Inc., where she worked on epitaxial growth of GaAs for microwave devices, development of high-efficiency and mm-wave IMPATT diodes, and multi-wafer epitaxy by the chloride transport process. In the fall of 1982, she joined the faculty of the Electrical and Computer Engineering Department at the University of Massachusetts/Amherst, where she became a full professor in 1993. She initiated metalorganic chemical vapor deposition (MOCVD), compound semiconductor materials and devices programs at UMass. Her research group performed studies on heterostructures, quantum wells, strained-layers, III-V selective epitaxy, as well as high-frequency and photonic devices. Professor Lau spent her first sabbatical leave in 1989 at the MIT Lincoln Laboratory. She developed acoustic sensors at the DuPont Central Research and Development Laboratory in Wilmington , Delaware during her second sabbatical leave ('95-'96). In the fall of 1998, she was a visiting professor at the Hong Kong University of Science and Technology (HKUST), where she joined the regular faculty since the summer of 2000. She established the Photonics Technology Center for R&D efforts in wide-gap semiconductor materials and devices. She became a Chair Professor of Electrical and Electronic Engineering at HKUST in July 2005.

Professor Lau is an IEEE Fellow, and a recipient of the National Science Foundation (NSF) Faculty Awards for Women (FAW) Scientists and Engineers. She served on the IEEE Electron Devices Society Administrative Committee and was an editor of the IEEE Transactions on Electron Devices (1996-2002). She also served on the Electronic Materials Committee of the Minerals, Metals and Materials Society (TMS) of AIME (American Institute of Materials Engineers).

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Recent Publications

  1. B. S. Zhang, H. Liang, Y. Wang, Z. H. Feng, K. W. Ng, K. M. Lau, “High-performance III-nitride blue LEDs grown and fabricated on patterned Si substrates”, Journal of Crystal Growth, vol.298, pp. 725-730, Jan 2007.  

  2. J. Liu, Y. Zhou, J. Zhu, Y. Cai, K. M. Lau, and K. J. Chen, "DC and RF Characteristics of AlGaN/GaN/InGaN/GaN Double-Heterojunction HEMTs," IEEE Trans. Electron Devices, vol.. 54, No. 1, pp. 2-10, Jan. 2007.

  3. Z. Cheng, Y. Cai, J. Liu, Y. G. Zhou, K. M. Lau, and K. J. Chen, "A Low Phase-Noise X-Band MMIC VCO Using High-Linearity and Low-Noise Composite-Channel Al0.3Ga0.7N/Al0.05Ga0.95N/ GaN  HEMTs", IEEE Trans. Microwave Theory and Techniques, vol. 55, No. 1, pp. 23-29, Jan 2007.

  4. L.M. Lin, Yi Luo, P.T. Lai, and K. M. Lau, “Influence of oxidation and annealing temperatures on quality of Ga2O3 film grown on GaN”, Thin Solid Films vol. 515, pp. 21112115, 2006

  5. R. Wang, Y. Cai, C. W. Tang, K. M. Lau, and K. J. Chen, “Enhancement-Mode Si3N4/AlGaN/GaN HISFETs,” IEEE Electron Device Lett., vol. 27, pp.793-795, Oct. 2006.

  6. Y. Cai, Z. cheng, W. C. W. Tang, K. M. Lau, and K. J. Chen "Monolithically integrated Enhancement-Mode AlGaN/GaN HEMT invertors and ring oscillators using CF4 plasma treatment," IEEE Trans. on Electron Devices, vol. 53, pp.2223-2229,  Sept, 2006.

  7. Y. Cai, Y. G. Zhou, K. M. Lau, and K. J. Chen "Control of Threshold Voltage of AlGaN/GaN HEMTs by Fluoride-based Plasma Treatment: From Depletion Mode to Enhancement Mode," IEEE Trans. Electron Devices, vol.. 53, pp. 2207-2215, Sept. 2006.

  8. Z. Yang, R. N. Wang, S. Jia, D. Wang, B. S. Zhang, K. M. Lau, and K. J. Chen, " GaN-on patterned-silicon (GPS) technique for fabrication of GaN-based MEMS ," Sensors and Actuators A vol. 130–131, pp 371–378, 2006.

  9. R. Wang, Y. Cai, W. Tang, K. M. Lau, and K. J. Chen, “Planar Integration of E/D-Mode AlGaN/GaN HEMTs Using Fluoride-Based Plasma Treatment,” IEEE Electron Device Lett., vol. 27, pp.633-635,  Aug. 2006.

  10. Z. Yang, R. N. Wang, S. Jia, D. Wang, B. S. Zhang, K. M. Lau, and K. J. Chen, "Fabrication of suspended GaN microstructures using GaN-on-patterned-silicon (GPS) technique," Phys. Sta. Sol. (a) 203, No. 7, pp.1712–1715 , 2006.

  11. S. Jia, Y. Cai, D. Wang, B. Zhang, K. M. Lau, and K. J. Chen, "Enhancement-Mode AlGaN/GaN High Electron Mobility Transistors on Silicon Substrates," IEEE Trans. on Electron Devices, vol. 53, pp.1474-1477, 2006.

  12. Y. Cai, Y. G. Zhou, K. M. Lau, and K. J. Chen "Enhancement-Mode AlGaN/GaN HEMTs with Low On-Resistance and Low Knee-Voltage," IEICE Trans. on Electronics, Vol.E89–C, No.7 pp.1025-1030 2006

  13. Z. H. Feng, S. J. Cai, K. J. Chen and K. M. Lau, “Isoelectronic indium-surfactant-doped Al0.3Ga0.7N/GaN high electron mobility transistors,” Appl. Phys. Lett., vol. 88, 122113, 2006.

  14. Z. Yang, R. N. Wang, S. Jia, D. Wang, B. S. Zhang, K. M. Lau, and K. J. Chen, “Mechanical characterization of suspended GaN microstructures fabricated by GaN-on-patterned-silicon technique,” Appl. Phys. Lett. vol.88, 041913, 2006.

  15. J. Liu, Y. Zhou, J. Zhu, K. M. Lau, and K. J. Chen, “AlGaN/GaN/InGaN/GaN DH-HEMTs with an InGaN Notch for Enhanced Carrier Confinement,” IEEE Electron Device Lett., vol. 27, pp.10-12,  Jan. 2006.

  16. Z. H. Feng, S.J. Cai, K. J. Chen, and K. M. Lau, “Enhanced Performance of AlGaN-GaN HEMTs Grown on Grooved Sapphire Substrates,” IEEE Electron Device Lett., vol. 26, pp.870-872, Dec. 2005.

  17. Z. Cheng, J. Liu, Y. G. Zhou, Y. Cai, K. J. Chen, and K. M. Lau, “Broadband Microwave Noise Characteristics of High-linearity Composite-channel Al0.3Ga0.7N/Al0.05Ga0.95N/GaN HEMTs,”  IEEE Electron Device Lett., vol. 26, pp.521-523, 2005.

  18. Z. H. Feng and K. M. Lau , “ Enhanced Luminescence from GaN-Based Blue LEDs Grown on Groov ed Sapphire Substrates,” IEEE Photon. Technol. Lett., vol. PTL-17, p.1812, September, 2005.

  19. C. S. Chu, Y. G. Zhou, K. J. Chen, and K. M. Lau , “Quality-factor Characterization of Radio-frequency GaN-based Metal-Semiconductor-Metal Planar Inter-digitated Varactors,”, IEEE Electron Device Lett., vol. 26, pp.432-434, 2005 .

  20. Y. Cai, Y. G. Zhou, K. J. Chen, and K. M. Lau , “High-Performance Enhancement-Mode AlGaN/GaN HEMTs Using Fluoride-based Plasma Treatment,” IEEE Electron Device Lett., vol. 26, pp.435-437, 2005 .

  21. Y. G. Zhou, R. M. Chu, J. Liu, K. J. Chen, and K. M. Lau , "Gate leakage in AlGaN/GaN HEMTs and its suppression by optimization of MOCVD growth," Phys. Sta. Sol.(c), 2, No.7, pp. 2663 – 2667, 2005.

  22. R. M. Chu , Y. G. Zhou , J. Liu, D. Wang, K. J. Chen, and K. M. Lau , "AlGaN-GaN Double-Channel HEMTs," IEEE Trans. Electron Devices, vol. 52, pp.438-446, 2005.

  23. J. Liu, Y. Zhou, R. Chu, Y. Cai, K. J. Chen, and K. M. Lau , “Highly Linear Al 0.3 Ga 0.7 N/Al 0.05 Ga 0.95 N/GaN Composite-Channel HEMTs ,” IEEE Electron Device Lett., vol. 26, pp.145-147, 2005.

  24. Y. D. Qi, H. Liang, D. Wang, W. Tang, Z. D. Lu , and K. M. Lau , “Comparison of Blue and Green InGaN/GaN MQW LEDs grown by Metalorganic Vapor Phase Epitaxy,” Appl. Phys. Lett., vol. 86, p.101903, 2005.

  25. S. Jia, Y. Dikme, D. Wang , K. J. Chen, K. M. Lau, and M. Heuken, “ AlGaN-GaN HEMTs on Patterned Silicon (111) Substrate s,” IEEE Electron Device Lett., vol. 26, pp.130-132, 2005.

  26. Y. Cai, Y. G. Zhou, K. J. Chen, and K. M. Lau , “III-Nitride Metal-Insulator-Semiconductor Heterojunction Field-Effect Transistors using Sputtered AlON Thin Films,” Appl. Phys. Lett., vol. 86, p.032109, 2005.

  27. D. Wang , S. Jia, K. J. Chen, K. M. Lau , Y. Dikme, P. van Gemmern, Y. C. Lin, H. Kalisch, R. H. Jansen , and M. Heuken, "Micro-Raman scattering study of stress distribution in GaN films grown on patterned Si(111) by metalorganic chemical vapor deposition," J. of Appl. Phys., vol. 97, p.056103, 2005.

  28. Z. H. Feng, Y. G. Zhou, S. J. Cai, and K. M. Lau, “Doping and Structural Dependence of the thermal stability of the 2DEG in GaN-based HEMT structures,” Jpn. J. of Appl. Phys., vol. 44, L21 – 23, 2005.

  29. Y. Zhou, D. Wang, R. Chu, C.W. Tang, Y. Qi, Z. Lu, K. J. Chen, K. M. Lau , “Correlation of In-situ reflectance spectra and resistivity of GaN/Al 2 O 3 interfacial layer in metalorganic chemical vapor deposition,” IEEE/TMS J. Electronic Materials, vol. 34, pp.112-118, 2005.

  30. D. Wang , Y. Dikme, S. Jia, P. van Gemmern, Y. C. Lin, K. J. Chen, K. M. Lau , P. van Gemmern, Y. C. Lin, H. Kalisch, R. H. Jansen, and M. Heuken, "Characterization of GaN grown on patterned Si(111) substrate," J. of Crystal Growth, vol. 272/1-4 pp. 489-495, 2004 .

  31. J. Zhang and K. M. Lau, “GaAs Esaki junctions with autocompensated impurities in the n-side by Metal-organic-chemical-vapor-deposition,” Appl. Phys. Lett., vol. 85, pp.4415-4417, 2004.

  32. Y. D. Qi, H. Liang, K. M. Lau , “Dual wavelength emission InGaN/GaN multi-quantum well LEDs grown by metalorganic vapor phase epitaxy,” J. of Crystal Growth, vol. 272/1-4 pp. 333-340, 2004 .

  33. Z. H. Feng, Y. G. Zhou, S. J. Cai, and K. M. Lau, “Enhanced thermal stability of the two-dimensional electron gas in GaN/AlGaN/GaN heterostructures by Si 3 N 4 surface passivation induced strain solidification,” Appl. Phys. Lett., vol. 85, pp.5248-5250, 2004.

  34. Z. H. Feng, Y. Qi, Z. D. Lu, Y. G. Zhou, K. M. Lau , “GaN-Based Blue-Light Emitting Diodes Grown and Fabricated on Patterned Sapphire Substrates Using Metalorganic Vapor Phase Epitaxy,” J. of Crystal Growth, vol. 272/1-4 pp. 327-332, 2004.

  35. J. M. Hwang , K. Y. Ho , Z. H. Hwang , W. H. Hung , K. M. Lau , and H. L. Hwang, “Efficient wet etching of GaN and p-GaN assisted with chopped UV source,” Superlattices and Microstructures, vol. 35, pp.45-57, 2004.

  36. J. Zhang, N. G. Anderson, and K. M. Lau , “ Al 0.10 Ga 0.90 As /GaAs Micro-coolers,” IEEE, Electron Device Letters, vol. 25, pp. 345-347, 2004.

  37. H. K. Kim, T. Y. Seong, I. Adesida, C. W. Tang, and K. M. Lau, “Low-resistance Pt/Pd/Au ohmic contacts to p-type AlGaN,” Appl. Phys. Lett., vol. 84, pp.1710-1712, 2004.