1. Seminar Paper review 報告者 : Y. T. Huang

2. 231 – 261 nm AlGaN deep-ultraviolet light-emitting diodes fabricated on AlN multilayer buffers grown by ammonia pulse-flow method on sapphire Hideki Hirayama APPLIED PHYSICS LETTERS 91, 071901 (2007)

3. High-Quality AlGaN Layers over Pulsed Atomic-Layer Epitaxially Grown AlN Templates for Deep Ultraviolet Light-Emitting Diodes J.P. ZHANG, H.M.WANG, W.H. SUN, V. ADIVARAHAN, S.WU, A. CHITNIS, C.Q. CHEN, M. SHATALOV, E. KUOKSTIS, J.W. YANG, and M. ASIF KHAN Journal of ELECTRONIC MATERIALS, Vol. 32, No. 5, 2003

4. Deep-Ultraviolet Light-Emitting Diodes Michael S. Shur, Fellow, IEEE, and Remis Gaska, Senior Member, IEEE IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 57, NO. 1, JANUARY 2010

5. Sensor Electronic Technology (SET), Inc. developed a new growth technique called migration-enhanced MOCVD (MEMOCVD®) [19]. This technique is an improved version of the pulsed atomic layer epitaxy (PALE) [20], which deposits ternary AlxGa1−xN or quaternary AlxInyGa1−x−yN layers [17], [21] by repeats of a unit cell grown using sequential metal–organic precursor pulses of Al, In, Ga, and ammonia (NH3). In PALE, the NH3 pulse always followed each metal–organic pulse and the duration of each pulse in the unit cell is fixed. In MEMOCVD, the durations and waveforms of precursor pulses are optimized, and the pulses might overlap, providing a continuum of growth techniques ranging from PALE to conventional MOCVD. Hence, MEMOCVD can support a high growth rate for buffer layers and a slower growth rate for active layers with reduced growth temperature (by more than 150 ◦C) and substantially improved quality. Using thisnew technique, we achieved a better mobility of precursor species on the surface and, thus, better atomic incorporation and improved surface coverage, allowing N/III separation, hence, reducing gas-phase reaction, enhancing surface migration. [19] Q. Fareed, R. Gaska, and M. S. Shur, “Methods of growing nitride-based film using varying pulses,” U.S. Patent 7 192 849, Mar. 20, 2007. [20] J. P. Zhang, E. Kuokstis, Q. Fareed, H. M. Wang, J. W. Yang, G. Simin, M. Asif Khan, G. Tamulaitis, G. Kurilcik, S. Jursenas, A. Zukauskas, R. Gaska, and M. Shur, “Pulsed atomic layer epitaxy of quaternary AlInGaN layers for ultraviolet light emitters,” Phys. Stat. Sol. (A), vol. 188, no. 1, pp. 95–99, Nov. 2001. [21] M. A. Khan, R. Gaska, M. S. Shur, and J. Yang, “Method of producing nitride-based heterostructure devices,” U.S. Patent 6 764 888, Jul. 20, 2004.

6. Thanks for your attention