Ya-Hong Xie

Professor Ya-Hong Xie
Tel. (310) 825-2971
FAX (310) 206-7353

Professor; BS in Physics, Purdue University (1981); MS (1983) & PhD (1986) in Electrical Engineering, University of California at Los Angeles; Member of the Technical Staff at Bell Laboratories (1986-1999); Professor of Material Science and Engineering, University of California at Los Angeles (1999-Current).

Ya-Hong Xie was born in Beijing, China. He entered the Physics Department of Peking University in 1977. After one and a half years, he transferred to the Physics Department of Purdue University. He obtained the B.S. degree in physics from Purdue University in 1981, and the M.S. and Ph. D degrees in electrical engineering from UCLA in 1983 and 1986, respectively. His Ph. D thesis research was on Si Molecular Beam Epitaxy under the guidance of Prof. Kang L. Wang.

Following graduation, Ya-Hong Xie joined AT&T Bell Laboratories (later became Bell Laboratories, Lucent Technologies). From 1986 until 1999, he had been a member of the technical staff at Bell Laboratories. His research activities during this period included impurity center mediated luminescence in Si (e.g. Er doped Si), light emitting porous Si, GeSi/Si molecular beam epitaxy, dislocation kinetics in relaxed GeSi/Si heterostructures, strain induced surface roughening in GeSi epitaxial thin films (also known as self-assembled quantum dots), fabrication of high mobility two-dimensional electron and hole gases in GeSi/Si, and the transport properties and device applications of various Si-based heterostructures.

Ya-Hong Xie joined UCLA as a professor of Materials Science & Engineering in 1999. His current research interests include the fabrication of 2D electron system in strained Si, epitaxial growth of self-assembled quantum dots of III-V and group IV semiconductors, RF crosstalk isolation and substrate impedance engineering for mixed-signal IC applications, and novel devices centered around Si CMOS technology.


Research Interests

Epitaxy of semiconductor nano-structures for achieving novel electronic and optoelectronic properties.


Area of Thesis Guidance

Epitaxy of semiconductor materials; the fabrication and understanding of strained layer semiconductor hetero-structures; phase change materials physics.


Recent Publications


  1. “Fabrication of dislocation-free Si films under uniaxial tension on porous Si compliant substrates”, Jeehwan Kim, Jae Young Lee, Ya-Hong Xie, Thin Solid Films, in press (2008);
  2. “3-D Finite Element Simulation of a PCRAM Cell with a Novel Self-insulated Structure”, Ke Sun, Feng Wen and Ya-Hong Xie, submitted to J. Appl. Phys. (2008);
  3. “The proximity effect of the regrowth interface on two-dimensional electron density in strained Si”, J. Lie, T. M. Lu, J. Kim, K. Lai, D. C. Tsui, and Ya-Hong Xie
    Appl. Phys. Lett. 92, 112113 (2008);
  4. “Epitaxial growth of two-dimensional electron gas (2DEG) in strained silicon for research on ultra-low energy electronic processes”, J. Liu, J.H. Kim, Y. H. Xie, T. M. Lu, K. Lai, and D. C. Tsui, Thin Solid Films, in press (2008);
  5. “A method for fabricating dislocation-free tensile-strained SiGe films via the oxidation of porous Si substrates”, Jeehwan Kim, Biyun Li, and Ya-Hong Xie
    Appl. Phys. Lett. 91, 252108 (2007).
  6. “Germanium-on-SOI photo-detector based on an FET structure”, Subal Sahni, Eli Yablonovitch, J Liu and Y.H. Xie, IEEE/OSA Conference on Lasers and Electro-Optics (CLEO), Baltimore, MD, May 2007.
  7. “Microstructure Analysis of Epitaxially Grown Self-Assembled Ge Islands on Nanometer-Scale Patterned SiO2/Si Substrates by High-Resolution Transmission Electron Microscopy”, T.S. Yoon, H.M. Kim, K.B. Kim, D.Y. Ryu, T.P. Russell, Z.M. Zhao, J. Liu, and Y.H. Xie, J. Appl. Phys. v.102, 104306 (2007).
  8. “Monolithic integrated modulator on silicon for optical interconnects”, Shi B, Chang PS, Sun K, Xie YH, Radhakrishnan, Monbouquette HG, IEEE PHOTONICS TECHNOLOGY LETTERS 19 (2-4): 55-57 JAN-FEB 2007.
  9. “Capacitively induced high mobility two-dimensional electron gas in undoped Si/SiGe heterostructures with atomic-layer-deposited dielectric”, T.M. Lu, J. Liu, J. Kim, K. Lai, D.C. Tsui, and Y. H. Xie, Appl. Phys. Lett., 90, 182114 (2007).
  10. “Lateral arrangement of Ge self-assembled quantum dots on a partially relaxed SiGe buffer layer”, H.J. Kim, Y.H. Xie and K.L. Wang, Ch. 7, page 209 in “Lateral Alingnment of Epitaxial Quantum Dots” O.G. Schmidt, ed., Springer, Berlin (2007).
  11. “Study of the nickel metallization in macroporous silicon using wet chemistry”, X. Zhang, K.N. Tu, and Y.H. Xie, submitted to IEEE Trans. Semicond. Manufac.
  12. “Nickel displacement deposition of porous silicon with ultrahigh aspect ratio”, C.K. Xu, Xi Zhang, K.N. Tu, Y.H. Xie, Journal of the Electrochemical Society, 154 (3), D170-D174, 2007.
  13. “Theoretical studies of displacement deposition of nickel into porous silicon with ultrahigh aspect ratio”, C.K. Xu, M.H. Li, Xi Zhang, K.N. Tu, Y.H. Xie, Electrochimica Acta, 52 (12), 3901-3909, 2007.
  14. “Monolithic integrated modulator on silicon for optical interconnects”, B. Shi, P. S. Chang, K. Sun, Y.H. Xie, C. Radhakrishnan, and H.G. Monbouquette, IEEE Photon. Techn. Lett., v.19, 55 (2007).


Book Chapters

  • “Three-dimensional impedance engineering for mixed-signal system-on-chip applications”, Kyuchul Chong and Ya-Hong Xie, in “Si-based RFIC”, W.Z. Cai, Editor, p.153-216, Transworld Research Publishers, publisher, 2006;
  • “Epitaxial growth of semiconductor self-assembled quantum dots”, H.J. Kim, Z.M. Zhao, B. Shi, J. Liu, and Y.H. Xie, book chapter in “Handbook of Semiconductor Nanostructrues and Nanodevices”, A. A. Balandin and K.L. Wang, Editors, American Scientific Pulishers (2006);


Professional Activities

  • Member of the organization committee, annual Electronic Materials Conference;
  • Member of the advisory committee, biannual International Conference on Si Epitaxy and Heterostructures;
  • Journal reviewer: JAP, APL, PR, JVST, IEEE, ECS, JCG, JEM; Acta Mat.;
  • Amberwave technical board of directors;
  • Legal consultant: Irell & Manella, LLP, Los Angeles, CA.


Courses Taught

MS120. Physics of Materials. Lecture, four hours; outside study, eight hours. Prerequisites: courses 14, 110. Introduction to electrical, optical, and magnetic properties of solids. Free electron model, introduction to band theory and Schrödinger wave equation. Crystal bonding and lattice vibrations. Mechanisms and characterization of electrical conductivity, optical absorption, magnetic behavior, and dielectrical properties.

MS121. Materials Science of Semiconductors. Prerequisite: course 120. Structure and properties of elemental and compound semiconductors. Electrical and optical properties, defect chemistry, and doping. Electronic materials analysis and characterization, including electrical, optical, and ion-beam techniques. Heterostructures, band-gap engineering, development of new materials for optoelectronic applications.

MS130. Phase Relations in Solids. Requisites: course 14, Chemical Engineering M105A or Mechanical and Aerospace Engineering M105A. Summary of thermodynamic laws, equilibrium criteria, solution thermodynamics, mass-action law, binary and ternary phase diagrams, glass transitions.

MS200. Principles of Materials Science I. (Formerly numbered 240B.) Lecture, four hours; outside study, eight hours. Prerequisite: course 120 or equivalent. Lattice dynamics and thermal properties of solids, classical and quantized free electron theory, electrons in a periodic potential, transport in semiconductors, dielectric and magnetic properties of solids.

MS224. Deposition Technologies and Their Applications. (Formerly numbered 248B.) Lecture, three hours; outside study, nine hours. Designed for graduate engineering students. Deposition methods used in high-technology applications. Theory and experimental details of physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma-assisted vapor deposition processes, plasma spray, electrodeposition. Applications in semiconductor, chemical, optical,  mechanical, and metallurgical industries.

MS226. Selected Topics in Materials Science from Modern Si-CMOS Technology, Lecture, three hours; discussion, one hour; outside study, eight hours. Recommended preparation: Electrical Engineering 221B. Requisites: courses 130, 131, 200, 221, 222. Introduction to Si CMOS technology with an emphasis on the short channel effects; additional topics include strained Si FETs, gate dielectric degradation, source/drain engineering including transient-enhanced diffusion, nonvolatile memory, and metallization for ohmic contacts. Letter grading



Research Group/Lab: Semi-Conductor Materials Research Lab


Office Location

  • 3121-F Engineering V


Mailing Address

  • UCLA, HSSEAS School of Engineering & Applied Sciences
    Department of Materials Science and Engineering
    410 Westwood Plaza
    3111 Engineering V
    Los Angeles, CA 90095-1595