近年來在紅光共振腔發光二極體有許多研究，但在氮化鎵材料的藍光共振腔發光二極體卻較少，主要因素是晶片磊晶困難，其中因為氮化鎵/氮化鋁鎵布拉格反射鏡伴隨鋁含量增加其折射率差異會變大，為得到高反射率須增大鋁含量，增加氮化鎵/氮化鋁鎵層數，也因此造成晶格的不匹配與應力無法釋放，而使發光二極體磊晶層龜裂，因此無法直接磊晶高品質、高反射的鏡面於結構中。為了克服無法獲得高品質氮化鎵/氮化鋁鎵布拉格反射鏡的缺點，以其它介電質反射鏡做為共振腔發光二極體的反射鏡研究，本論文利用二氧化鈦/二氧化矽的材料製作具有高反射率的布拉格反射鏡；此種結構之基板需薄化或移除使介電質布拉格反射鏡能夠蒸鍍於兩側，故於本論文中，首先利用雷射剝離技術將藍寶石基板移除後，利用活性離子蝕刻機進行蝕刻薄化結構並以化學機械研磨機拋光使表面平坦化。製作傳統的發光二極體與具有布拉格反射鏡的發光二極體，作為對照組。具有布拉格反射鏡的發光二極體是使用電子槍蒸鍍介電質布拉格反射鏡二氧化鈦/二氧化矽的多層膜蒸鍍在發光二極體上層。最後測量元件的電特性與光特性，其元件的電特性在20mA的起始電壓為3.7V，元件的光特性在光峰值為450nm，半高寬由原本的17.2nm在蒸鍍反射鏡後減少到10nm。

　　For recent years, many researches have been published in red RCLED, but few papers have been published on GaN based RCLED. The main reason is the difficulty of growing structures. If the multilayer materials of AlGaN and GaN were used to from the DBR in the GaN based RCLED structure. We can increase the mole of Al or increase the AlGaN/GaN pairs to increase the reflectivity of the DBR. However, it has a problem of lattice mismatch between AlGaN and GaN. If we increase the mole of Al or increase the AlGaN/GaN pairs, it will generate cracks in the films. Therefore, we can not obtain the high quality and high reflectivity of the DBR. We will choose two materials of dielectric that have large difference of refractive index to replace the AlGaN/GaN to form high quality DBR. In this thesis, we used the multilayer material of TiO2/SiO2 as the external DBR in the GaN based RCLED. However, in this design, the substrate must be removed or thinned to deposit the DBR at the two sides of GaN based RCLED structure.
　　Firstly, the laser will be used to remove the sapphire. The reactive ion etching will be used to remove the buffer layer to the n-type GaN layer. We will also use the chemical mechanical polishing to improve the roughness of the n-type GaN surface.
　　In this thesis, we fabricated the GaN based LED with and without the multilayer material of TiO2/SiO2 as the external DBR. We also measured the performance of the traditional LED (without external DBR) and the RCLDE (with external DBR). The threshold voltage of the RCLED is 3.7V at the operating current of 20mA. The FWHM decrease from 17.2nm to 10nm where peak is at 450nm.

Chapter 1
[1]D. Byrne , F. Natali , B. Damilano, A. Dussaigne, N. Grandjean and J. Massies, “Blue resonant cavity light emitting diodes with a high-Al-content GaN/AlGaN distributed Bragg reflector,” Jpn. J. Appl. Phys. Lett., Vol. 42, pp. 1509-1511, 2003.
[2]M. A. Di Forte-Poisson, A. Romann, M. Tordjman, M. Magis and J. di Persio, “Growth optimisation of GaInN/GaN multiple quantum well structures: application to RCLED devices,” Phys. Stat. Sol.(A), , Vol. 192, pp. 435-440, 2002.
[3]H. Amano, N. Sawaki, I. Akasaki and Y. Toyoda, “Metalorganic vapor phase epitaxial growth of a high guality GaN flim using an AlN buffer layer,” Appl. Phys. Lett., , Vol. 48, pp. 353-355, 1986.
[4]A. J. Shaw, A. L. Bradley, J. F. Donegan, and J. G. Lunney, “GaN resonant cavity light-emitting diodes for plastic optical fiber applications” IEEE Phot. Tec. Lett., Vol. 16, pp. 2006-2008, 2004.
[5]M. de la Fargue and M. Missous, “Effects of high index plane on device performances of near-infraredInGaAs/GaAs/AlGaAs resonant-cavity light-emitting diodes,” IEEE Optoelectronics, Vol. 147, pp. 27-30, 2000.
[6]X. Jin, S. Q. Yu, Y. Cao, D. Ding, J. B. Wang, N. Samal, Y. Sadofyev, S. R. Johnson and Y. H. Zhang, “1.3 μm GaAsSb resonant-cavity light-emitting diodes grown on GaAs substrate,” Lasers and Electro-Optics Soci., Vol. 1, pp. 69-70, 2003.
[7]F. Natali, D. Byrne, A. Dussaigne, N. Grandjean and J. Massies, “High-Al-content crack-free AlGaN/GaN Bragg mirrors grown by molecular-beam epitaxy” Appl. Phys. Lett., Vol. 82, pp. 499-501, 2003.
[8]Y. K. Song, M. Diagne, H. Zhou and A. V. Nurmikko, “Resonant-cavity InGaN quantum-well blue light-emitting diodes,” Appl. Phys. Lett., Vol. 77, pp. 1744-1746, 2000.
[9]T. Margalith: Ph. D. Thesis, Materials Department, University of California Santa Barbara, Santa Barbara, 2002.
[10]C. F. Chu, C. C. Yu, H. C. Cheng, C. F. Lin and S. C. Wang, “Comparison of p-Side Down and p-Side Up GaN light-emitting diodes fabricated by laser lift-off,” Jpn. J. Appl. Phys., Vol. 42, pp. 147-150, 2003.
[11]W. S. Wong, T. Sands, N. W. Cheung, M. Kneissl, D. P. Bour, P. Mei, L. T. Romano and N. M. Johnson, “InxGa1–xN light emitting diodes on Si substrates fabricated by Pd–In metal bonding and laser lift-off,” Appl. Phys. Lett., Vol. 77, pp. 2822-2824, 2000.
Chapter 2
[1]C. Wilmsen, H. Temkin and L. A. Coldren : Vertical cavity surface emitting lasers design, fabrication, characterization, and applications, p. 203, 1998.
[2] N. E. J. Hunt, E. F. Schubert, R. A. Logan, and G. J. Zydzik, “Enhanced spectral power density and reduced linewidth at 1.3 µm in an InGaAsP quantum well resonant-cavity light-emitting diode,” Appl. Phys. Lett., Vol. 61, pp. 2287-2289, 1992.
Chapter 3
[1]T. Fujii, A. David, C. Schwach, P. M. Pattison, R. Sharma, K. Fujito, T. Margalith, S. P. Denbaars, C. Weisbuch and S. Nakamura, “Micro cavity effect in GaN-Based light-emitting diodes formed by laser lift-off and etch-back,” Jpn. J. Appl. Phys. Lett., Vol. 43, pp. 411-413, 2004.
[2]H. L. Zhu, L. A. Tessaroto, R. Sabia, V. A. Greenhut, M. Smith and D. E. Niesz, “Chemical mechanical polishing (CMP) anisotropy in sapphire,” Appl. Sur. Sci., Vol. 236, pp. 120-130, 2004.
[3]C. T. Lee and H. W. Kao, “Long-term thermal stability of Ti/Al/Pt/Au ohmic contacts to n-type GaN,” Appl. Phys. Lett., Vol. 76, pp. 2364-2366, 2000.
Chapter 4
[1]T. Fujii, A. David, C. Schwach, P. M. Pattison, R. Sharma, K. Fujito, T. Margalith, S. P. Denbaars, C. Weisbuch and S. Nakamura, “Micro cavity effect in GaN-Based light-emitting diodes formed by laser lift-off and etch-back,” Jpn. J. Appl. Phys. Lett., Vol. 43, pp. 411-413, 2004.
[2]G. Yu, G. Wang , H. Ishikawa , M. Umeno, T. Soga, T. Egawa, J. Watanabe and T. Jimbo, “Optical properties of wurtzite structure GaN on sapphire around fundamental absorption edge (0.78-4.77 eV) by spectroscopic ellipsometry and the optical transmission method,” Appl. Phys. Lett., Vol. 70, pp. 3209-3211, 1997.