從有機金屬化學氣相磊晶(MOCVD)技術的快速發展，即被普遍地應用各種材料的磊晶生長，並獲得優良的結晶品質。近年來，化合物半導體的研究發展及應用更是受到各界的矚目，也是當前國家所要全力推動的重點科技項目之一。其中以大量地應用在通訊、照明、交通等方面之磷化鋁鎵銦發光二極體(AlGaInP-based light-emitting diodes)為大家所熟知，其發出的光波段則介於可見光區中的紅~黃綠光區。
本研究採用磷化鋁鎵銦發光二極體做為試片，利用偏壓式輔助光電化學反應對試片的最上層磷化鎵也就是窗口層(window layer)進行濕性蝕刻。由於光電化學反應其蝕刻機制為一非等向性之濕性蝕刻，所以對p型磷化鎵表面會有粗糙化的效果，並利用電解液不同的pH值來探討蝕刻後的表面情形。
接下來就是利用不同的表面型態應用在我們的磷化鋁鎵銦發光二極體上。我們可知道當窗戶層表面為平整時，從量子井所散射出表面的光子量會因為光全反射的關係而有所下降。因此對試片表面進行粗糙化可降低光全反射的機會，進而提高發光效率。且在本論文會利用TracePro光學模擬軟體來模擬不同表面型態的發光效率，再與實驗結果做分析比較。

Since the technique of metal-organic chemical vapor deposition (MOCVD) was rapidly developed, it was applied generally in various kinds of epitaxy, receiving the outstanding crystal quality. Recently, the research and application of chemical composition semiconductor is more looked at attentively and it is also one of the focal technique events that the country spares no effort to promote it. It is known well for everyone that AlGaInP-based light-emitting diodes are applied on a large scale in communication、illumination、traffic etc. Its emitting light from the red to yellow-green part of the spectrum were made available.
In this thesis, we choose AlGaInP-based light-emitting diodes as samples, and etch the surface of GaP by using bias-assisted photoelectrochemical(PEC) method. Because PEC is an anisotropic wet etching method, we can use bias-assisted PEC method to rough the surface of p-type GaP, and there are different etching surfaces on different pH value of electrolyte.
We can increase emitting efficiency of light-emitting diodes by roughing p-type GaP with bias-assisted PEC method. It is know that the relation between different etching surface and emitting efficiency. In the end, results of experiment will be compared to the simulation of TracePro.

[1] E. F. Schubert, Light-Emitting Diodes, Cambridge University Press, (2003).
[2] P. Harrison, Quantum Wells, Wires and Dots, 2nd Ed., John Wiely & Sons, LTD (2005).
[3] S. Nakamura,“InGaN-based violet laser diodes”, Semicond. Sci. Technol., 14, 27 (1999).
[4] I. Schnitzer, E. Yablonovitch, C. Caneau, and A. Scherer,“30% external quantum efficiency from surface textured, thin film lightemitting diodes”, Appl. Phys. Lett., 63, 2174 (1993).
[5] E. F. Schubert, N. E. J. Hunt, M. Micovic, R. J. Malik, D. L. Sivco, A.Y. Cho, and G. J. Zydzik,“Highly efficient light-emitting diodes with microcavities”, Science, 265, 943 (1994).
[6] T. Baba, R. Watanabe, K. Asano, F. Koyama, and K. Iga,“Theoretical and experimental estimations of photon recycling effect in light emitting devices with a metal mirror”, J. J. Appl. Phys., 35, 97 (1996).
[7] A. Kock, E. Gornik, M. Hauser, and W. Beinstingl,“Strongly directional emission from AlGaAs/GaAs light-emitting diodes”, Appl. Phys. Lett., 57, 2327 (1990).
[8] R. Windisch, P. Heremans, A. Knobloch, P. Kiesel, G. H. Dohler, B. Dutta, and G. Borghs,“Light-emitting diodes with 31% external quantum efficiency by outcoupling of lateral waveguide modes”, Appl. Phys. Lett., 74, 2256 (1999).
[9] A. F. Wright and J. S. Nelson,“Bowing parameters for zinc-blende Al1-xGaxN and Ga1-xInxN”, Appl. Phys. Lett., 66, 3051 (1995).
[10]史光國，工業材料148 期，149 (1999).
[11] K. H. Kish, J. G. Yu, C. P. Kuo, R. M. Flectcher, T. D. Osentowski, L. J.Stinson, and M. G. Craford, “High-efficiency InGaAlP/GaAs visible light-emitting diodes”, Appl. Phys. Lett., 58, 1010 (1991).
[12] J. E. Borton, C. Cai, M. I. Nathan, P. Chow, J. M. Van Hove, A. Wowchak, and H. Morkoc,“Bias-assisted photoelectrochemical etching of p-GaN at 300 K”, Appl. Phys. Lett., 77, 1227 (2000).
[13] J. M. Hwang, K. Y. Ho, Z. H. Hwang, W. H. Hung, K. M. Lau, and H. L. Hwang, Superlattices and Microstructures, (2004).
[14] H. O. Finkiea, Semiconductor Electrodes, Netherlands, Elsevier Science (1998).
[15] G. B. Stringfellow, and M. G. Craford, High Brightness Light Emitting Diodes,Academic Press, Boston, (1997).