本論文主要為應用成熟的發光二極體製造技術，設計並製作出主動式960x540氮化鎵微型化發光二極體陣列。在圖形化的藍寶石基板(PSS)上，用有機金屬化學氣相沉積系統(MOCVD)製作出氮化鎵磊晶層，再利用感應偶合電漿離子蝕刻系統(ICP-RIE)蝕刻出磊晶層的高原(MESA)，鍍上n與p電極後，使用電漿輔助化學氣相沉積系統(PECVD)沉積介電質絕緣層，最後用電漿離子蝕刻系統開出金屬接點通道(Via)後，鍍上銦接點，用覆晶封裝技術(Flip-chip bonding)和控制電路接合，利用背面出光，便可以實現主動式控制發光二極體陣列的目標。
發光二極體具有長壽命、高效率、低功耗、高亮度、耐候性佳等等優點，以往發光二極體的發展大部分是以取代傳統照明方式為主，但在本論文中，我們希望把發光二極體的種種優點擴展到新的領域，因此微型化發光二極體陣列應運而生。為了將其應用於攜帶式投影器和無光罩微影技術，高光強度、高效率、低功耗、高均勻度都是很重要的因素。首先我們設計了銦錫氧化物透明導電薄膜層，使電流能夠均勻的分佈並通過量子井，令電子電洞對復合發光的效率提高，發光強度因而增強，此外，此透明導電薄膜層能夠和p+型氮化鎵層形成歐姆接觸，進一步降低可能產生的能量損耗，達到低功耗的要求。磊晶片我們使用十層量子井的結構，目的是希望盡可能將注入的電子電洞對捕捉並復合轉化成光，藉以提升出光強度和效率。至於磊晶高原的蝕刻是採用比較溫和的感應耦合電漿蝕刻參數，目的是降低蝕刻缺陷，進而抑制漏電流的產生。為了提高微型化發光二極體陣列的出光均勻度，我們也設計了適當的網格狀n型電極，使各像素電流路徑的串連電阻值盡量達到一致，同時也使用覆晶封裝技術使得接線路徑降到最低，更進一步減低能量傳遞損耗，並用Macleod光學薄膜分析軟體計算絕緣披覆層的厚度，形成全反射層，反射正面出光光線，增加背面出光強度。最後為了避免每顆像素之間光訊號互相干擾，我們盡可能的將藍寶石基板減薄，並進行拋光除去細微刮痕，除此之外，上面提到的網格狀n型電極也能有效的區隔各像素，令發散出來的光線侷限在像素中心。
在本論文中，我們使用了各種不同結構的磊晶片，主要的研究波段在於450nm藍光波段、525nm綠光波段及370nm紫外光波段。此微型化發光二極體的像素中心到中心距離為12.8微米，每顆像素的大小為7.8微米，陣列的長為13.824毫米，寬為8.448毫米，對角線長度為0.55英吋 (14.098毫米)。
至於各磊晶片單一像素的特性，在負5伏特的逆偏壓之下，藍光波段的逆向漏電流為0.1 pA，綠光波段的逆向漏電流為0.25 pA，紫外光的逆向漏電流為3.26 pA。在開路電壓之下，藍光波段的最小電流為1 fA，綠光波段的最小電流為0.02 fA，紫外光的最小電流為5 fA。在正偏壓之下，藍光波段的啟動電壓為2.75 V，綠光波段的啟動電壓為2.55 V，紫外光的啟動電壓為3.15 V。此微型化發光二極體陣列藍光波段的光電轉換效率為2.329 %，綠光波段的光電轉換效率為1.3 %，紫外光波段的光電轉換效率為2.1 %。最後，我們成功製作完成並展示藍光的微型化發光二極體陣列顯示，其畫素存活率高達99.674 %.

In this thesis, the major goal is to develop an individually addressable 960×540 Gallium Nitride (GaN) based micro-light emitting diode array in assistant of mature LED processing technique: On top of patterned sapphire grows a thin GaN epitaxy layer, and using inductively-coupled plasma reactive ion etching (ICP-RIE) system, a MESA of epitaxy layer is then formed, after n-metal and p-metal is deposited [1][2], using plasma-enhanced chemical vapor deposition system (PECVD) to deposit dielectric layer, and via hole for indium bump is etched by RIE system, last, flip chip bonding is performed, the micro-LED array is now ready to display with the help of SDK controller.
Light emitting diode has many advantages such as long life time, high luminous efficiency, low power consumption, high brightness, and operates at harsh condition, traditional applications of LED mostly focus on illumination purpose, but we hope to make good use of LED’s tremendous advantages, and here comes the idea of micro-LED array. To develop a high brightness, high power efficiency, low power consumption, good uniformity micro-LED array and integrated into pico-projectors or mask-free lithography, first, we design an Indium Tin Oxide (ITO) current spreading layer for higher brightness and better power efficiency, next, the epitaxial wafer with ten quantum wells for active layer is used to increase the chance of electron-hole pair recombination. By the way, LED MESA is etched with gentle recipe, and passivation layer is adopted to reduce side wall damage and restrain leakage currant. For better optical output uniformity, we design a grid-shaped n-metal to lowering series resistance for each pixel to be similar, at the same time, flip-chip bonding technique is adopt for shorter current path and smaller series resistance. In order to increase light output from backside of micro-LED array, a specially designed passivation layer is deposited for total reflection at front side, and sapphire substrate is polished with decreased thickness to avoid light crosstalk when displaying.
In this thesis, we use various structure of epitaxial grown wafer, including wafer emits blue light, green light, and UV light, the pitch of 960×540 micro-LED array is 12.8μm, the diameter of each pixel is 7.8μm, the length of 960×540 micro-LED array is 12.288 mm, width is 6.912 mm, and diagonal length is 0.55 inch (14.098 mm).
As for the single pixel characteristics of micro-LED array, the reverse leakage current at -5 volts for blue LED is 0.1 pA, for green LED is 0.25 pA, for UV LED is 3.26 pA. At open circuit voltage, the open circuit current for blue LED is 1 fA, for green LED is 0.02 fA, for UV LED is 5 fA. At forward bias, the turn on voltage for blue LED is 2.75 V, for green LED is 2.55 V, for UV LED is 3.15 V. The power efficiency of micro-LED array for blue LED is 2.329%, for green LED is 1.3%, for UV LED is 2.1%.
At last, we successfully demonstrate a working sample of micro-LED display with blue light, with an operability of 99.674%

摘 要 I
Abstract III
誌謝 V
Contents VI
List of Figures VIII
Chapter 1 Introduction 1
1-1 Introduction to Light Emitting Diodes 1
1-2 Research motivation 2
Chapter 2 The Basic Theory 9
2-1 The basic theory of Light Emitting Diodes 9
2-2 LED I-V Characteristic 11
2-3 L-I Characteristic 17
2-4 E-L Characteristic 21
Chapter 3. Experimental procedure 24
3-1 Device Structure and mask design concept 24
3-2 Process Steps and Experimental Details 35
3-3Measurement means and characterization instruments 44
3-3-1 Transmission line measurement 44
3-3-2 I-V and L-I measurement system 44
3-3-3 E-L measurement system 45
Chapter 4. Result and Discussion 47
4-1 The blue micro-LED array characteristic measurement 47
4-1-1 ITO film characteristic and p-metal contact resistance 48
4-1-2 I-V characteristic and analysis 49
4-1-3 L-I characteristic and analysis 51
4-1-4 E-L characteristic and analysis 53
4-1-5 Uniformity analysis 54
4-1-6 Operability analysis 55
4-2 The green micro-LED array characteristic measurement 57
4-2-1 ITO film characteristic and p-metal contact resistance 57
4-2-2 I-V characteristic and analysis 58
4-2-3 L-I characteristic and analysis 60
4-2-4 E-L characteristic and analysis 62
4-3 The UV micro-LED array characteristic measurement 63
4-3-1 ITO film characteristic and p-metal contact resistance 63
4-3-2 I-V characteristic and analysis 64
4-3-3 L-I characteristic and analysis 66
4-3-4 E-L characteristic and analysis 68
Chapter 5. Conclusions 69
References 71

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