簡易檢索 / 詳目顯示

回結果列表
研究生： 汪信呈
Wang, Hsin-Cheng
論文名稱： 使用新式的圖案化藍寶石基板來有效地改善氮化鎵系列的發光二極體
Efficiency improvement of GaN-based LEDs using patterned sapphire substrate
指導教授： 蘇炎坤
Su, Yan-Kuin
許進恭
Sheu, Jinn-Kong
學位類別： 碩士
Master
系所名稱： 理學院 - 光電科學與工程研究所
Institute of Electro-Optical Science and Engineering
論文出版年： 2008
畢業學年度： 96
語文別： 英文
論文頁數： 114
中文關鍵詞： 圖案化藍寶石基板 、發光二極體 、溼式蝕刻
外文關鍵詞： patterned sapphire substrate, LED, wet etching
相關次數： 點閱：89  下載：1 
分享至:
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報

    • 隨著固態照明演進至此，以發光二極體 (LEDs) 取代傳統白熾燈泡的瓶頸主要仍在亮度的提升和價格昂貴等方面。本論文中我們研究團隊使用藍寶石基板來製作圖形化之基板。為了解決上述所提到的亮度提升和價格問題。因此，我們主要在利用溼式蝕刻的方法來製作圖案化的藍寶石基板。
    在基板製備方面，我們主要將實驗分成三個部份。乾式蝕刻、溼式蝕刻和圖案化藍寶石基板的應用。在乾式蝕利的實驗，我們發現到使用凸的藍寶石圖形的晶格品質會比凹的藍寶石圖形來的好。原因在於凹的圖形有很大的機會造成磊晶層無法完全包覆藍寶石基板，而且所產生的空隙不但會造成晶格品質的下降也會影響光的取出率。此外，若我們將凸的圖形尺寸縮小，效能會因為散射面面積的增加而提升。當發光二極體操作在室溫及順向電流20mA時，對於圓洞圖案之基板其輸出功率與外部量子效率是9.07mW與16.33%，大圓柱圖案之基板 (直徑和間距階為3μm)為9.52mW與16.85%，小圓柱圖案之基板 (直徑和間距階為
    2μm)為9.61mW與17.31%，而傳統平坦的藍寶石基板為7.93mW與12.59%。順帶一提，大圓柱圖案之基板和傳統平面基板的發光二極體相較之下，輸出功率有著20%之提升。在溼式蝕刻的實驗，同樣製作著有凸和凹的圖形化藍寶石基板，由於藍寶石基石的各個晶格面的蝕刻速率不一樣，所以製作出來的圖案為像一個盾牌圖案(凸)和賓士圖案(凹)。在元件的輸出功率與外部量子效率方面，盾牌圖案之基板為9.89mW與17.77%，賓士圖案之基板為9.54mW與17.22%。
    從此結果可以發現，溼式蝕刻所製作的凸的藍寶石基板有效能比乾式蝕刻製作的還高。這是由於溼式蝕刻所製作出來的圖案化基板的傾角(slanted sidewall angle)比乾式製作出來的還小，所以相對的增加了散射面的面積。進一步地，我們利用此盾牌構來做些微的結構變化，使其散射面積更大。在元件的輸出功率與外部量子效率方面，此深度為8000Α的新式圖案藍寶石基板為10.29mW與18.57%。若與傳統平面基板的發光二極體相較之下，輸出功率有著29.7%之提升。在最後一部份的實驗則是圖案化藍寶石基板的應用(Patterned material on sapphire substrate : PMOSS)。主要的動機在利用ELOG增加磊晶品質的功能並且結合圖案化藍寶石基板增加光取出率的能力。在磊晶方面的分析，我們利用高解析度X光繞射光譜之半高寬、漏電流、穿透式電子顯微鏡之影像、etch pit density (EPD)量測與壽命測試來評估氮化鎵磊晶層的結晶品質並且發現其磊晶品質比乾式蝕刻所製作出來的圓柱圖案化藍寶石基板好。在元件的輸出功率與外部量子效率方面，此結構(PMOSS)為9.84mW與17.78%。若與傳統平面基板的發光二極體相較之下，輸出功率有著24%之提升。

    With the development of solid-state lighting, the chief bottlenecks of traditional incandescent lamps replaced with light emitting diodes (LEDs) were luminance enhancements and problem of cost down. In this paper, our group presents the patterned sapphire substrate by wet etching method for the most part to solve the above-mentioned problems. In our experiment, we would like to divide the three part for dry etching, wet etching and PSS’s application. For dry etching, from the leakage current, XRD, EPD and lifetime of experiment, we can see that the convex pattern has better crystal quality of GaN epilayer than the concave pattern. Because the structure of concave-PSS has air-gap, they could produce the poorer crystal quality. It should be noted that the air-gap could affect the optical characteristics with the change of refractive index. In this respect of size effect, the small size (2μm diameter and 2μm spacing) of convex pattern has better performance than the large size (3μm diameter and 3μm spacing) of convex pattern from the results of optical analysis. This is due to the increase of scattering surface area for small size of convex pattern. When the LEDs was operated at a forward current of 20mA at room temperature, the light output power and the external quantum efficiency were estimated to be 9.07mW and 16.33% for concave-PSS, 9.52mW and 16.85% for large-convex-PSS, 9.61mW and 17.31% for small-convex-PSS, and 7.93mW and 12.59% for conventional planar sapphire substrate, respectively. For wet etching, the light output power and the external quantum efficiency were estimated to be 10.29mW and 18.57% for structure with 8000Α-ASP. From this result, we could see that this structure with much more area of scattering surface not only solve the problem of cost down but also enhance the performance. In addition, the output power can be enhanced around 30% with the 8000Α-ASP-structure, as compared to the structure with conventional planar sapphire substrate. In PSS’s application, from the electrical characteristics, optical characteristics, XRD, EPD and lifetime, we could see that the enhanced performance could be due to combination of improved light extraction efficiency and the reduction in dislocation density using this structure. The light output power and the external quantum efficiency were estimated to be 9.84mW and 17.78% for this structure. In addition, the output power can be enhanced around 24% with this structure, as compared to the structure with conventional planar sapphire substrate.

    Contents Abstract (in Chinese) --------------------------------------------- Ⅰ Abstract (in English) --------------------------------------------- Ⅲ Acknowledgement ------------------------------------------------ Ⅴ Content ------------------------------------------------------------- Ⅵ Table Captions ------------------------------------------------ Ⅸ Figure Captions --------------------------------------------------- Ⅹ Chapter 1 Introduction -------------------------------------------------------- 1 1-1 A brief History of Light Emitting Diodes -------------------- 1 1-2 Background of this Research and Motivation --------------- 3 1-3 Research Direction and Skeleton ----------------------------- 5 Chapter 2 Basic Principle ---------------------------------------------------- 7 2-1 Brief Principle of Etching -------------------------------------- 7 2-1-1 Wet Etching ----------------------------------------------- 7 2-1-2 Dry Etching ----------------------------------------------- 8 2-2 Patterned Sapphire Substrate --------------------------------- 10 Chapter 3 Experiment ------------------------------------------------------- 19 3-1 Dry Etching ----------------------------------------------------- 19 3-1-1 Motivation ----------------------------------------------- 19 3-1-2 Experimental Details ----------------------------------- 19 3-2 Wet Etching ----------------------------------------------------- 21 3-2-1 Motivation ----------------------------------------------- 21 3-2-2 Experimental Details ---------------------------------- 21 3-2-2-1 Etching Solution ------------------------------ 22 3-2-2-2 Process of Patterned Sapphire Substrate -- 23 3-2-2-3 Process of Novel Structure ------------------ 24 3-2-3 Etching Equipment ------------------------------------- 25 3-3 Patterned Material on Sapphire Substrate ------------------ 25 3-3-1 Motivation ----------------------------------------------- 25 3-3-2 Experimental Details ----------------------------------- 26 Chapter 4 Results and Discussion ----------------------------------------- 59 4-1 Dry etching ----------------------------------------------------- 59 4-1-1 Devices Analysis ---------------------------------------- 59 4-1-1-1 Electrical Characteristics -------------------- 59 4-1-1-2 Optical Characteristics ----------------------- 61 4-1-1-3 Lifetime ---------------------------------------- 62 4-1-2 Summary ------------------------------------------------- 63 4-2 Wet Etching ----------------------------------------------------- 63 4-2-1 Analysis of Etching Solution -------------------------- 63 4-2-2 Crystalline Analysis ------------------------------------ 65 4-2-3 Devices Analysis ---------------------------------------- 65 4-2-3-1 Benz pattern versus Shield pattern --------- 66 4-2-3-1-1 Electrical Characteristics --------- 66 4-2-3-1-2 Optical Characteristics ----------- 67 4-2-3-2 Advanced Shield Pattern --------------------- 69 4-2-3-2-1 Electrical Characteristics --------- 69 4-2-3-2-2 Optical Characteristics ----------- 70 4-2-4 Summary ------------------------------------------------- 71 4-3 PMOSS --------------------------------------------------------- 71 4-3-1 Devices Analysis ---------------------------------------- 71 4-3-1-1 Electrical Characteristics -------------------- 72 4-3-1-2 Optical Characteristics ----------------------- 73 4-3-1-3 Lifetime ---------------------------------------- 74 4-3-2 Summary ------------------------------------------------- 74 Chapter 5 Conclusions and Future works ------------------------------ 106 5-1 Conclusions --------------------------------------------------- 106 5-2 Future works -------------------------------------------------- 106 Reference ---------------------------------------------------------------------- 109 Table Captions Table 1-1 The information for every groups utilizes the patterned sapphire substrate to fabricate the LEDs from 2001 to the present ----------------------------------- 6 Table 2-1 Summarized basic properties of dry and wet etching method -------------- 17 Table 2-2 The critical angle between various kinds of materials ----------------------- 18 Table 4-1 The information of some measured data (Dry). ----------------------------- 101 Table 4-2 Summarized optical properties of GaN epilayer grown on three kinds of PSS by dry etching and conventional sapphire substrate. ------------------ 101 Table 4-3 Basic information of sapphire. ------------------------------------------------- 102 Table 4-4 The information of some measured data (Shield). -------------------------- 103 Table 4-5 Summarized optical properties of GaN epilayer grown on four kinds of PSS by wet etching and large-convex-PSS by dry etching. --------------------- 103 Table 4-6 The information of some measured data (ASP). ---------------------------- 104 Table 4-7 Summarized optical properties of GaN epilayer grown on five kinds of PSS by wet etching, large-convex-PSS by dry etching and conventional sapphire substrate. -------------------------------------------------------------------------- 104 Table 4-8 The information of some measured data (PMOSS). ------------------------ 105 Table 4-9 Summarized optical properties of GaN epilayer grown on the structure with PMOSS and large-convex-PSS. ----------------------------------------------- 105 Table 5-1 Summarized optical properties of all the samples. -------------------------- 106 Table 5-2 The process of simulation. ----------------------------------------------------- 106 Figure Captions Fig. 2-1 The mechanism of wet etching method. ----------------------------------------- 14 Fig. 2-2 The three mechanism of dry etching method (a) Ion bombardment of physical property (b) Reactive etching of chemical property (c) Reactive ion etching --------- 15 Fig. 2-3 Schematic of the patterned sapphire substrate. --------------------------------- 16 Fig. 2-4 The light extraction ratio from LED surfaces using the trace simulation. --- 16 Fig. 2-5 The mechanism of light extraction of patterned sapphire substrate. --------- 17 Fig. 3-1 The photograph image of concave pattern of photoresist. --------------------- 27 Fig. 3-2 The cross-sectional SEM micrograph of the concave holes. ------------------ 27 Fig. 3-3 The SEM micrograph of top view of concave holes. -------------------------- 28 Fig. 3-4 The cross-sectional view of concave holes with some tilt angle. ------------- 28 Fig. 3-5 The flowchart of concave holes by dry etching method. ---------------------- 29 Fig. 3-6 The photograph image of convex pattern of photoresist. (a) Large convex columns (3x3) (b) Small convex columns (2x2) ---------- 30 Fig. 3-7 The cross-sectional SEM micrographs of sapphire etched with convex columns by ICP. (a) Cross-sectional SEM micrograph of large convex columns. (b) Top view SEM micrograph of small convex columns. -------- 30 Fig. 3-8 The top view SEM micrographs of sapphire etched with convex columns by ICP. (a) Top view SEM micrograph of large convex columns. (b) Top view SEM micrograph of small convex columns. ------------------------------------ 31 Fig. 3-9 The cross-sectional view of convex columns with some tilt angle. (a) SEM micrograph of large convex columns. (b) SEM micrograph of small convex columns. -------------------------------- 32 Fig. 3-10 The flowchart of convex columns by dry etching method. ------------------ 34 Fig. 3-11 The micrograph of the chip with patterned sapphire. (a) Top view SEM micrograph of chip structure (b) The structure with patterned sapphire substrate ------------------------- 35 Fig. 3-12 The photograph image shows the four patterns of SiO2. (a) large convex (3x3) (b) small convex (2x2) (c) large concave (3x3) (d) small concave (2x2) ---------------------------------------------------------- 36 Fig. 3-13 The flowchart of concave holes (Benz) by wet etching method. ------------ 37 Fig. 3-14 The flowchart of convex columns (Shield) by wet etching method. ------- 38 Fig. 3-15 The top view SEM micrographs of patterned sapphire by etching solution. (a) Top view SEM image of Benz pattern. (b) Top view SEM image of Shield pattern. ---------------------------------- 39 Fig. 3-16 The cross-sectional view SEM micrographs of Benz pattern by high-temperature etching solution. (a) SEM micrograph of Benz pattern. (b) SEM micrograph of Benz pattern with some tilt ang--------------------- 40 Fig. 3-17 The cross-sectional view SEM micrographs of Shield pattern by high-temperature etching solution. (a) SEM micrograph of Shield pattern. (b) SEM micrograph of Shield pattern with some tilt angle. ---------------- 41 Fig. 3-18 The AFM micrograph shows the patterned sapphire substrate after wet etching. (a) 2D image of concave pattern by wet etching (Benz pattern). (b) 3D image of concave pattern by wet etching (Benz pattern) (c) 2D image of convex pattern by wet etching (Shield pattern). (d) 3D image of convex pattern by wet etching (Shield pattern). ---------- 42 Fig. 3-19 The photograph image shows the concentric convex columns of SiO2. -- 46 Fig. 3-20 The SEM micrographs of novel structure and Shield pattern by high-temperature etching solution. (a) Top view SEM image of Shield pattern (b) Top view SEM image of ASP (c) Cross-sectional SEM image of Shield pattern (d) Cross-sectional SEM image of ASP ---------------------- 46 Fig. 3-21 The cross-sectional SEM micrographs of two kinds of ASP with some tilt angle. (a) Low magnification of ASP with height of 0.5μm. (b) High magnification of ASP with height of 0.5μm. (c) Low magnification of ASP with height of 0.8μm. (d) High magnification of ASP with height of 0.8μm. ---------------------- 48 Fig. 3-22 The cross-sectional SEM images of ASP with different slanted sidewall angle. (a) SEM micrograph of ASP with height of 0.5μm. (b) SEM micrograph of ASP with height of 0.8μm. ------------------------------------- 50 Fig. 3-23 The AFM micrograph shows the patterned sapphire substrate after wet etching. (a) 2D image of ASP by wet etching. (b) 3D image of ASP by wet etching. ----------------------------------------------------------------------------- 52 Fig. 3-24 The picture of equipment for high-temperature wet etching. --------------- 54 Fig. 3-25 The SEM image of convex pattern of photoresist and SiO2. (a) The SEM image of convex pattern of photoresist before dry etching. (b) The SEM image of convex pattern of SiO2 after dry etching. (c) Cross-sectional SEM micrograph of PMOSS (d) Cross-sectional SEM micrograph of PMOSS with small tilt angle. (e) Cross-sectional SEM micrograph of PMOSS with large tilt angle. ---- 54 Fig. 3-26 The flowchart of Patterned material on sapphire substrate (PMOSS). ----- 57 Fig. 3-27 The LED chip with the structure of PMOSS. ---------------------------------- 58 Fig. 4-1 Forward I-V characteristics of concave holes, large convex columns and small convex columns by dry etching method. ------------------------------- 75 Fig. 4-2 Reverse-bias current as a function of voltage of the concave holes, large convex columns and small convex columns by dry etching method. -------- 75 Fig. 4-3 DCXRD rocking curves of (0002) peak for concave-PSS, large-convex-PSS and small-convex-PSS. ------------------------------------------------------------ 76 Fig. 4-4 The SEM micrograph of three different PSS with epilayers. (a) Cross-sectional view of structure of concave holes (b) Cross-sectional view of structure of large convex columns (c) Cross-sectional view of structure of small convex columns -------------- 76 Fig. 4-5 Luminous intensity as a function of forward current of concave holes, large convex columns and small convex columns by dry etching method with To-can. ------------------------------------------------------------------------------- 78 Fig. 4-6 Output power and external quantum efficiency as a function of forward current for the LEDs grown on the three different patterns by dry etching method. ------------------------------------------------------------------------------- 78 Fig. 4-7 The far field patterns of PSS LEDs of the concave holes, large convex columns and small convex columns by dry etching method. ----------------- 79 Fig. 4-8 Lifetime result of concave-PSS, large-convex-PSS, small-convex-PSS and conventional LEDs at room-temperature and 20mA. -------------------------- 80 Fig. 4-9 Etching rate of α-sapphire at 300°C as function of the H2SO4:H3PO4 mixture ratio. ---------------------------------------------------------------------------------- 80 Fig. 4-10 The SEM micrographs of various mixture of H2SO4 and H3PO4. (a) Top view of SEM micrograph at the mixture ratio of 1:1. (b) Top view of SEM micrograph at the mixture ratio of 3:1. (c) Cross-sectional view of SEM micrograph at the mixture ratio of 3:1. (d) Cross-sectional view of SEM micrograph at the mixture ratio of 5:1. - 81 Fig. 4-11 Labeling of planes in hexagonal symmetry for sapphire. -------------------- 83 Fig.4-12 The diagram and SEM micrographs for crystalline analysis. (a) The diagram of various crystalline plane for sapphire substrate (b) Cross-sectional SEM micrograph of ASP with some tilt angle. (c) Cross-sectional SEM micrograph of ASP ---------------------------------- 83 Fig. 4-13 Forward I-V characteristics of the shield and the Benz by wet etching method and the convex column by dry etching method. -------------------- 85 Fig. 4-14 Reverse-bias current as a function of voltage of the shield and the Benz by wet etching method and the convex column by dry etching method. ------ 85 Fig. 4-15 The SEM micrograph of three different PSS with epilayers. (a) Cross-sectional view of structure of large Shield pattern (3x3). (b) Cross-sectional view of structure of small Shield pattern (2x2). (c) Cross-sectional view of structure of large Benz pattern (3x3). (d) Cross-sectional view of structure of small Benz pattern (2x2). --------- 86 Fig. 4-16 Luminous intensity as a function of the shield and the Benz by wet etching method and the convex column by dry etching method with To-can. ------ 88 Fig. 4-17 Output power and external quantum efficiency as a function of forward current for the LEDs grown on the five different patterns with To-can. --- 88 Fig. 4-18 The far field patterns of PSS LEDs of the shield and the Benz by wet etching method and the convex column by dry etching method. ----------- 89 Fig. 4-19 Forward I-V characteristics of ASP, shield and Benz by wet etching method and the convex column by dry etching method. ------------------------------ 90 Fig. 4-20 Reverse-bias current as a function of voltage of ASP, shield and Benz by wet etching method and the convex column by dry etching method. ------ 90 Fig. 4-21 The SEM micrograph of four different PSS with epilayers. (a) Cross-sectional view of structure of 8000Α-ASP. (b) Cross-sectional view of structure of 5000Α-ASP. (c) Cross-sectional view of structure of 8000Α-Benz. (d) Cross-sectional view of structure of 5000Α-Benz. ------------------------ 91 Fig. 4-22 Luminous intensity as a function of ASP, shield and Benz by wet etching method and the convex column by dry etching method with To-can. ------ 93 Fig. 4-23 Output power and external quantum efficiency as a function of forward current for the LEDs grown on the six different patterns with To-can. ---- 93 Fig. 4-24 The far field patterns of PSS LEDs of ASP, shield and Benz by wet etching method and the convex column by dry etching method. --------------------- 94 Fig. 4-25 Forward I-V characteristics of PMOSS and large convex columns by dry etching method. -------------------------------------------------------------------- 95 Fig. 4-26 Reverse-bias current as a function of voltage of the PMOSS and large convex columns by dry etching method. --------------------------------------- 95 Fig. 4-27 DCXRD rocking curves of (0002) peak for the structure with PMOSS and large convex columns. ------------------------------------------------------------ 96 Fig. 4-28 The SEM micrograph of two different structures with epilayers. (a) Cross-sectional view of the structure with PMOSS. (b) Cross-sectional view of the structure with convex columns (3x3). ---- 96 Fig. 4-29 Luminous intensity as a function of forward current of the structure with PMOSS and large convex columns with To-can. ------------------------------- 97 Fig. 4-30 Output power and external quantum efficiency as a function of forward current for the LEDs grown on the two different structures of patterned sapphire. ---------------------------------------------------------------------------- 98 Fig. 4-31 The far field patterns of PSS LEDs of the PMOSS and large convex columns by dry etching method. ------------------------------------------------ 99 Fig. 4-32 Lifetime result of the structure with PMOSS and large convex columns LEDs at room-temperature and 20mA. --------------------------------------- 100

    [01] E. Fred Schubert, “ Light-Emitting Diodes,” second edition, pp. 1-16, 2006
    [02] S. Nakamura, T. Mukai, M. Senoh, and N. Iwasa, "Thermal annealing effects on
    p-type Mg-doped GaN films," Jpn. J. Appl. Phys., vol. 31, pp. L139-L142, 1992.
    [03] H. Amano, N. Sawaki, I. Akasaki, and T. Toyoda, "Metalorganic vapor phase
    epitaxial growth of a high quality GaN film using an AlN buffer layer," Appl.
    Phys. Lett., vol. 48, pp. 353-355, 1986.
    [04] Y. Narukawa, J. Narita, T. Sakamoto, K. Deguchi, T. Yamada and T. Mukai, “Ultra-High Efficiency White Light Emitting Diodes,” Jap. J. Appl. Phys., vol. 45, no. 41, pp. L1084-L1086, 2006
    [05] S. Yoshida, S. Misawa, and S. Gonda, “Improvement on the electrical and luminescent properties of reactive molecular beam epitaxially grown GaN films by using AlN-coated sapphire substrates” Appl. Phys. Lett., vol. 42, no. 5, pp. 427-429, 1983
    [06] H. Amano, N. Sawaki, and I. Akasaki, “Metalorganic vapor phase epitaxial grown of a high quality GaN film using an AlN buffer layer” Appl. Phys. Lett., vol. 48, no. 5, pp. 353-355, 1986
    [07] Wei-Kai Wang, Dong-Sing Wuu , Shu-Hei LIN, Shih-Yung Huang, Pin Han and Ray-Hua Horng, “Characteristics of Flip-Chip InGaN-Based Light-Emitting Diodes on Patterned Sapphire Substrates” Jap. J. Appl. Phys., vol. 45, no. 4B, pp. 3430–3432, 2006
    [08] Dong-Ho Kim, Chi-O Cho, Yeong-Geun Roh, Heonsu Jeon, and Yoon Soo Park, “Enhanced light extraction from GaN-based light emitting diodes with holographically generated two dimensional photonic crystal patterns” Appl. Phys. Lett., vol. 87, 2005
    [09] S. H. Huang, R. H. Horng, K. S. Wen,Y. F. Lin, K. W. Yen, and D. S. Wuu, “Improvement light extraction of nitride-based flip-chip light-emitting diodes via sapphire shaping and texturing” IEEE PTL, vol. 18, no. 24, 2006
    [10] W. K. Wang, D. S. Wuu, S. H. Lin, P. Han, R. H. Horng, and T. C. Hsu, “Efficiency improvement of near-ultraviolet InGaN LEDs using patterned sapphire substrates” IEEE QE, vol. 41, no. 11, 2005
    [11] A. Hayes, J.F. Welden, E. Ostun, and R.J. Gambino, Data Storage 43
    (March/April 1995)
    [12] J. W. Kim, Y. C. Kim, and W. J. Lee, “Reactive ion etching mechanism of plasma enhanced chemically vapor deposited aluminum oxide film in CF4/O2 plasma” J. Appl. Phys., vol. 78, no. 3, pp. 2045-2049, 1995
    [13] J. B. Fedison, T. P. Chow, H. Lu, and I. B. Bhat, “Reactive ion etching of GaN in BCl3/N2 plasma” J. Electrochem. Soc., vol. 144, no. 8, pp. L221-L224, 1997
    [14] X. Dongzhu, Z. Dezhang, P. Haochang, X. Hongjie, and R. Zongxin, “Enhanced etching of sapphire damaged by ion implantation” J. Phys. D: Appl. Phys., vol.31, pp. 1647-1651, 1998
    [15] H. Ishiwara, H. Yamamoto, and S. Furukawa, “Lateral solid phase epitaxy of amorphous Si films on Si substrates with SiO2 patterns” Appl. Phys. Lett., vol.43, no. 11, pp. 1028-1030, 1983
    [16] M. Grundmann, A. Krost, D. Bimberg, O. Ehrmann, and H. Cerva, “Maskless growth of InP stripes on patterned Si (000a): Defect reduction and improvement of optical properties” Appl. Phys. Lett., vol. 60, no. 26, pp. 3292-3294, 1992
    [17] K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, Y. Imada, M. Kato and T. Taduchi, “High output power InGaN ultraviolet light emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy” Jpn. J. Appl. Phys., vol. 40, pp. L583-585, 2001
    [18] C. C. Sun, C. Y. Lin, T. X. Lee, and T. H. Yang, “ Enhancement of light extraction of GaN-based light emitting diodes with a microstructure array” OE Lett., vol. 43, no. 8, pp. 1700-1701, 2004
    [19] 莊達人『VLSI 製造技術』，pp. 263-278
    [20] S. J. Pearton, J. C. Zolper, R. J. Shul, and F. Ren, “GaN: Processing, defects, and devices” J. Appl. Phys., vol.86, 1999
    [21] E. Fred Schubert, “ Light-Emitting Diodes,” second edition, pp. 86-90, 2006
    [22] Shuji Nakamura, “InGaN Multiquantum-Well-Structure Laser Diodes with GaN–AlGaN Modulation-Doped Strained-Layer Superlattices” IEEE Sle. Topics in Quan. Electr., vol. 4, no. 3, 1998
    [23] Hyung Koun Cho, Dong Chan Kim, Hee Jun Lee, Hung Seob Cheong, Chang Hee Hong, “Microstructural analysis of GaN films grown by a two-step technique on patterned GaN and sapphire” Superlat. & Microst., vol. 36, pp. 385-391, 2004
    [24] K.J. Linthicum, T. Gehrke, D.B. Thomson, K.M.Tracy, “Process routes for low defect-density GaN on various Substrates employing pendeo-epitaxial growth techniques” JNRS, 1999
    [25] A.M. Roskowski, P.Q. Miraglia, E.A. Preble, S. Einfeldt, R.F. Davis, “Surface instability and associated roughness during conventional and pendeo-epitaxial growth of GaN (0001) films via MOVPE” JCG, vol. 241, pp. 141-150, 2002
    [26] Isao Kidoguchi, Akhiko Ishibashi, Gaku Sugahara and Yuzaburoh Ban, “Air bridged lateral epitaxial overgrowth of GaN thin films” Appl. Phys. Lett., vol. 76, 2000
    [27] Yasutoshi Kawaguhi, Gaku Sugahara, Atsunori Mochida, Toshitaka Shimamoto, Akihiko Ishibashi, and Toshiya Yokogawa, “Low dislocation density AlGaN layer by air bridged lateral epitaxial growth” Phys. Stat. sol. (c), vol. 0, no. 7, pp. 2107-2110, 2003
    [28] Y. Chen, R. Schneider, S.Y. Wang, R. S. Kem, C. H. Chen, and C. P. Kuo, “Dislocation resuction in GaN thin films via lateral overgrowth from trenches” Appl. Phys. Lett. Vol. 75, 1999
    [29] Carol I. H. Ashby, Christine C. Mitchell, Jung Han, Nancy A. Missert, Paula P. Provencio, David M. Follstaedt, Gregory M. Peake, and Leonardo Griego, “Low dislocation density GaN from a single growth on a texture substrate” Appl. Phys. Lett. vol. 77, 2000
    [30] E. Fred Schubert, “ Light-Emitting Diodes,” second edition, pp. 91-97, 2006
    [31] I. Niki, Y. Narukawa, D. Morita, S. Sonobe, T. Mitani, and H. Tamaki, “White LEDs for solid state lighting” Proc. of SPIE, vol. 5187, p. 3, 2004
    [32] H.S. Cheong, M.K. Yoo, H. G. Kim, S. J. Bae, C. S. Kim, C. H. Hong,
    J. H. Baek, H. J. Kim, Y. M. Yu, and H. K. Cho, “Direct heteroepitaxial lateral overgrowth of GaN on stripe patterned sapphire substrates with very thin SiO2 masks” Phys. Stat. Sol. (b), vol. 241, no. 12, pp. 2763-2766, 2004
    [33] P. Visconti, K. M. Jones, M. A. Reshchikov, R. Cingolani, H. Morkoc, and
    R. J. Molnar, “Dislocation density in GaN determined by photoelectrochemical and hot-wet etching” Appl. Phys. Lett., vol. 77, no. 22, 2000
    [34] F. Dwikusuma, D. Saulys, and T. F. Kuech, “Study on sapphire surface preparation for Ⅲ-nitride heteroepitaxial growth by chemical treatments” J. Electrochem. Soc., vol.149, no. 11, pp. G603-G608, 2002
    [35] 謝奇勳、藄振瀛，『成長於圖案化藍寶石基板之氮化鎵發光二極體特性分析』pp. 12-13, 2007
    [36] Y. J. Lee, H. C. Kuo, T. C. Lu, B. J. Su, and S. C. Wang, “Fabrication and characterization of GaN-based LEDs grown on chemical wet-etched patterned sapphire substrates” J. Electrochem. Soc., vol. 153, no. 12, pp. G1106-G1111, 2006
    [37] M. Yamada, T. Mitani, Y. Narukawa, S. Shioji, I. Niki, S. Sonobe, K. Deguchi, M. Sano and T. Mukai, “InGaN-based near ultraviolet and blue light emitting diodes with high external quantum efficiency using a patterned sapphire substrate and a mesh electrode” Jpn. J. Appl. Phys., vol. 41, pp. L1431-L1433, 2002
    [38] S. Watanabe, N. Yamada, and M. Nagashima, “Internal quantum efficiency of highly efficient InxGa1-xN-based near ultraviolet light emitting diodes” Appl. Phys. Lett., vol. 83, no. 24, 2003
    [39] H. Kudo, Y. Ohuchi, T. Jyouichi, T. Tsunekawa, and H. Okagawa, “Demonstration of high efficient InGaN based violet light emitting diodes with an external quantum efficiency of more than 40%” Phys. Stat. sol. (a), vol. 200, pp. 95-98, 2003
    [40] S. J. Chang, Y. C. Lin, Y. K. Su, C. S. Chang, and T. C. Wen, “Nitride-based LEDs fabricated on patterned sapphire substrates” Sol. Stat. elect., vol. 47, 2003
    [41] Y. P. Hsu, S. J. Chang, and Y. K. Su, “Lateral epitaxial patterned sapphire InGaN/GaN MQW LEDs” J. Cry. Crow., vol. 261, 2004
    [42] Y. J. Lee, T. C. Hsu, H. C. Kuo, and M. J. Jou, “Improvement in light output efficiency of near ultraviolet InGaN-GaN LEDs fabricated on stripe patterned sapphire substrates” Material Sci. Eng. B, vol. 122, 2005
    [43] D. S. Wuu, K. Wang, W. C. Shih, and R. H. Horng, “Enhanced output power of near ultraviolet InGaN-GaN LEDs grown on patterned sapphire substrates” IEEE PTL, vol. 17, no. 2, 2005
    [44] W. K. Wang, W. S. Wuu, S. H. Lin, and R. H. Horng, “Efficiency improvement of near ultraviolet InGaN LEDs using patterned sapphire substrates” IEEE QE, vol. 41, no. 11, 2005

    [45] W. K. Wang, D. S. Wuu, W. C. Shih, and R. H. Horng, “Near ultraviolet InGaN/GaN light emitting diodes grown on patterned sapphire substrates” Jap. J. Appl. Phys., vol. 44, no. 4B, 2005
    [46] W. K. Wang, D. S. Wuu, S. H. Lin, S. Y. Huang, and R. H. Horng, “InGaN-based light emitting diodes grown on grooved sapphire substrates” Phys. Stat. sol. (c), vol. 3, no. 6, pp. 2141-2144, 2006
    [47] D. S. Wuu, W. K. Wang, K. S. Wen, S. C. Huang, S. H. Lin, R. H. Horng, and Y. S. Yu, “Fabrication of pyramidal patterned sapphire substrates for high efficiency InGaN-based light emitting diodes” J. Electrochem. Soc., vol. 153, no. 8, 2006
    [48] D. S. Wuu, W. K. Wang, K. S. Wen, S. C. Huang, and S. Y. Huang, “Defect reduction and efficiency improvement of near ultraviolet emitters via laterally overgrown GaN on a GaN/patterned sapphire template” Appl. Phys. Lett., vol. 89, no. 161105, 2006
    [49] Y. J. Lee, J. M. Hwang, T. C. Hsu, M. H. Hsieh, and H. C. Kuo, “Enhancing the output power of GaN-based LEDs grown on wet-etched patterned sapphire substrates” IEEE PTL, vol. 18, no. 10, 2006
    [50] C. C. Pan, C. H. Hsieh, C. W. Lin, and Jen Inn Chyi, “Light output improvement of InGaN ultraviolet light emitting diodes by using wet-etched stripe-patterned sapphire substrates” J. Appl. Phys., vol. 102, no. 084503, 2007

    下載圖示 校內：2009-06-23公開
    校外：2010-06-23公開
    QR CODE