Keh-Yung Cheng

Keh-Yung Cheng
Keh-Yung Cheng
Professor Emeritus


  • Ph.D. Electrical Engineering Stanford University 1975
  • M.S. Electrical Engineering Stanford University 1972
  • B.S. Electrical Engineering Chung-Cheng Institute of Technology, Taiwan 1969


Professor Cheng received the Ph.D. degrees in Electrical Engineering from Stanford University, Stanford, California in 1975. From 1975 to 1979, he was a faculty member with the Department of Electrical Engineering, Chung-Cheng Institute of Technology in Taiwan. In 1979, he joined Dr. A. Y. Cho’s group at Bell Laboratories, Murray Hill, NJ, where he began research in molecular bean epitaxy (MBE) technology. His research in this area led to the development of rotating substrate holder for uniform MBE growth, the enhancement of electron mobility in modulation doped GaInAs/AlInAs/InP heterostructures, and the first demonstration of GaInAs/AlInAs/InP HEMT. The rotating sample holder design becomes an indispensable component of MBE systems and is now a standard feature of every modern production MBE system. Presently, the MBE grown GaInAs/AlInAs HEMTs exhibit the best overall performance with fT ≥520 GHz and are extensively studied and widely used.

Since 1987, he has been with the Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign (UIUC), where he is presently a Professor. From 2000 to 2004, he was the Director of the Bio-Optoelectronic Sensor Systems (BOSS) Center. The BOSS Center was a consortium of seven universities and sponsored by DARPA. In 2004, he became the Director of the Hyper-Uniform Nanophotonic Technologies (HUNT) for Ultra-Fast Optoelectronic Systems Center. The HUNT Center is a consortium of the University of Illinois, Columbia University, Georgia Tech and Harvard University, and sponsored by DARPA under the University Photonics Research Centers program. The focus of the HUNT Center was to accomplish ultra-high (> 40 GHz) optoelectronic interconnect systems using a revolutionary ultra-fast transistor laser design, incorporated with quantum wells and quantum dots in the base region, which could be directly modulated at a speed beyond THz. During the 2003 academic year, he was a Ministry of Education Distinguished Visiting Chair Professor at the Institute of Optoelectronic Technology, National Tsinghua University, Taiwan. At UIUC, he made further contributions to the compound semiconductors including the first demonstration of dilute nitride III-V-N (GaP1-xNx) compound semiconductors, the invention of quantum wire heterostructure lasers using discovered strain-induced lateral layer ordering (SILO) process, and the demonstration of the world fastest double heterojunction bipolar transistor (DHBT) (fT ≥650GHz) using GaAsSb/InP type-II heterostructures. His pioneering work of the first observation of the dramatic bandgap energy bowing in dilute III-V-N compound semiconductors has led a great deal of follow-up research on similar material systems including the arsenic-rich Ga(In)AsN compounds currently being pursed at many major research groups. His current research interests are in the areas of in situ fabrication of low-dimensional optoelectronic materials and devices, novel high-speed optoelectronic devices, and the development of mid-IR optoelectronic devices. He has published more than 200 technical papers on compound semiconductor materials and devices.

Dr. Cheng is a Fellow of IEEE and a Fellow of the American Association for the Advancement of Science (AAAS). In 2007, he received MBE Innovator Award from North American MBE Conference for his extraordinary contributions to the research and development of MBE technology for device applications.

Academic Positions

  • Professor, Electrical & Computer Engineering, University of Illinois - August 1995 to present (100%)
  • Professor, National Tsing Hua University, Taiwan, 1987
  • Professor, Chung-Cheng Institute of Technology, Taiwan, 1981-1986

Other Professional Employment

  • MTS, Bell Laboratories, Murray Hill, NJ, 1979-1981

Teaching Statement

I have been teaching "ECE488- Compound semiconductor and devices" regularly and serving as the course director. During the past two semesters, I have been offering an experimental course equivalent to ECE440 - ECE398NC.

Research Statement

My current research focuses on 1) the development of ultra-high-speed GaAsSb-based heterojunction bipolar transistors with cutoff frequency near Tera Hz, 2) fundamental studies on fabricating hyper-uniform nanostructures using nano-imprint lithograph and in-situ processing technologies, and 3). exploring III-V alloy-based MOSFET technologies for future integrated circuits applications.

Undergraduate Research Opportunities

Undergraduate research opportunities in areas of compound semiconductor materials and device fabrication are available for students who are looking for challenging topics. Some journal publications done by undergraduate students (*) are listed below:

1. R. H. Chan* and K. Y. Cheng, "Optimization the reactive ion etching of p-InGaP with CH4/H2 by a two-level fractional factorial design process", J. Vac. Sci. and Technol., B14, 3219-3225, 1996

2. J.H. Epple, C. Sanchez*, T. Chung, K.Y. Cheng, and K.C. Hsieh, "Dry etching of GaP with emphasis on selective etching over AlGaP," J. Vac. Sci. and Technol. B20, 2252-2255, 2002.

3. K. Meneou*, H. C. Lin, K. Y. Cheng, J. G. Kim and R. U. Martinelli, "Wet thermal oxidation of AlAsSb alloys lattice matched to GaSb", J. Appl. Phys., 95, 5131-5136, 2004.

Research Interests

  • Molecular beam epitaxy technology, optoelectronic and high speed devices, in-situ fabrication of nanostructures, and III-V MOSFETs.

Research Areas

  • Semiconductor electronic devices
  • Semiconductor lasers and photonic devices
  • Semiconductor materials

Selected Articles in Journals

  • K. Meneou and K.Y. Cheng, ˜Soft Photocurable Nanoimprint Lithography for Compound Semiconductor Nanostructures', J. Vacuum Sci. Technol. B 26, 156 (2008)
  • William Snodgrass, Bing-Ruey Wu, K. Y. Cheng, and Milton Feng, 'Type-II GaAsSb/InP DHBTs With Record fT = 670 GHz and Simultaneous fT, fMAX > 400 GH', Proceedings of 2007 International Electron Devices Meeting, Washington DC, December 10-12, 2007
  • Chiun-Lung Tsai, K. Y. Cheng, Shu-Ting Chou, Shih-Yen Lin, 'InGaAs quantum wire infrared photodetectors', Appl. Phys. Lett., 91, 181105 (2007)
  • K. Meneou, C. L. Tsai, Z. H. Zhang, and K. Y. Cheng, 'Site-controlled InAs Quantum Dots on GaAs Patterned Using Self-Organized Nano-channel Alumina Template', J. Vacuum Sci. Technol. B 23, 1232-1235, 2005.
  • H. C. Lin, W. H. Wang, K. C. Hsieh, and K. Y. Cheng, "Fabrication of 1.55 µm VCSELs on Si using metallic bonding," Electronics Letters, vol. 38, pp. 516-517, 2002.
  • M. Hong, Z. H. Lu, J. Kwo, A. R. Kortan, J. P. Mannaerts, J. J. Krajewski, K. C. Hsieh, L. J. Chou, and K. Y. Cheng, "Initial growth of Ga2O3(Gd2O3) on GaAs: Key to the attainment of a low interfacial density of states," Applied Physics Letters, vol. 76, pp. 312-314, 2000.
  • D. E. Wohlert, S. T. Chou, A. C. Chen, K. Y. Cheng, and K. C. Hsieh, "Observation of temperature-insensitive emission wavelength in GaInAs strained multiple-quantum-wire heterostructures," Applied Physics Letters, vol, 68, p. 6, 1996.
  • J. N. Baillargeon, K. Y. Cheng, and A. Y. Cho, "GaInAs/GaAs/GaInP strained quantum well lasers (l~0.98 µm) grown by MBE using solid phosphorus and arsenic valved cracking cells," Applied Physics Letters, vol. 67, p. 2960, 1995.
  • X. Liu, S. G. Bishop, J. N. Baillargeon, and K. Y. Cheng, "Band gap bowing in GaP1-xNx alloys," Applied Physics Letters, vol. 63, p. 208, 1993.
  • K. Y. Cheng, K. C. Hsieh, and J. N. Baillargeon, "Formation of lateral quantum-well in vertical short-period superlattices by strain induced lateral layer ordering," Applied Physics Letters, vol. 60, p. 2892, 1992.
  • J. N. Baillargeon, K. Y. Cheng, G. E. Hofler, and K. C. Hsieh, "Luminescence quenching and the formation of the GaP1-xNx alloy in GaP with increasing nitorgen content," Applied Physics Letters, vol. 60, p. 2540, 1992.
  • J. N. Baillargeon, K. Y. Cheng, P. J. Pearah, G. E. Hofler, and K. C. Hsieh, "Growth and liminescence properties of Ga:P and GaP1-xNx," Journal of Vacuum Science Technology, vol. B 10, p. 829, 1992.
  • K. Y. Cheng, K. C. Hsieh, J. N. Baillargeon, and A. Mascarenhas, "Formation of lateral quantum-wells in vertical short-period superlattices", Proc. of 1991 Int. Symp. GaAs and related Compounds, (Inst. Phys. Sr. 120), p. 589-594, 1992, Seattle, WA, USA
  • C. Y. Chen, A. Y. Cho, K. Y. Cheng, T. P. Pearsall, P. O'Connor, and P. A. Garbinski, "Depletion mode modulation doped A10.48In0.52As-Ga0.47In0.53As heterojunction foeld effect transistors," IEEE Electron Device Letters, vol. EDL-3, p. 152, 1982.
  • K. Y. Cheng, A. Y. Cho, T. J. Drummond, and H. Morkoc, "Electron mobilities in moduation doped Ga0.47In0.53As/A10.48In0.52As heterojunctions grown by molecular beam epitaxy," Applied Physics Letters, vol. 40, p. 147, 1982.
  • A. Y. Cho and K. Y. Cheng, "Growth of extremely uniform layers by rotating substrate holder with molecular beam epitaxy for applications to electro-optic and microwave devices," Applied Physics Letters, vol. 38, p. 360, 1981.

Conferences Organized or Chaired

  • Program committee chair of 2008 International Conference on MBE, August 2008, Vancouver, Canada.
  • Symposium Organizer, Materials Research Society Spring Meeting, Symposium C: Strained Layer Epitaxy - Materials, Processing, and Device Applications, San Francisco, CA, April 1995
  • Conference Chair, 1994 North American Conference on Molecular Beam Epitaxy, October 10, 1994, Urbana, Illinois

Professional Societies

  • Advisory board member, North American Conference on MBE, 1995-.
  • Treasurer, North American Molecular Beam Epitaxy Conference, 1998-.


  • 2007 MBE innovator award, September 2007.
  • Ministry of Education Distinguish Visiting Chair Professor, National Tsing-Hua University, Hsinchu, Taiwan, 2003-2004
  • Fellow of the American Association for the Advancement of Science (AAAS), 2003
  • Fellow of IEEE, 2002
  • Visiting Research Fellow, Nagoya University, Nagoya, Japan, May-August 2000
  • 1985 Distinguished Research Award of the National Science Council, Taiwan, ROC

Teaching Honors

  • 2009 Engineering Council Award for Excellence in Advising (April 28, 2009)