圖案化藍寶石基板應用於覆晶結構發光二極體特性之研究

本研究以感應耦合電漿蝕刻系統將藍寶石晶圓蝕刻出規則重複排列圓形圖案，製作成圖案化之藍寶石基板，隨後在圖案化藍寶石基板上利用有機金屬化學氣相沉積系統成長氮化鎵發光二極體結構（發光波長為410 nm），並封裝成覆晶型式探討其元件特性。實驗結果顯示，在元件光輸出功率上比傳統藍寶石基板覆晶結構發光二極體上高59%，元件光輸出功率的提升可以歸因於氮化鎵薄膜成長於圖案化藍寶石基板上會產生橫向磊晶的效果而造成氮化鎵磊晶品質改善，以及藍寶石基板上的凹凸圖案會產生光散射的效果增加光的取出率。

We report on the characteristics of high-power near-ultraviolet flip-chip InGaN light-emitting diodes (LEDs) fabricated onto a patterned sapphire substrate (PSS). When the PSS flip-chip LED (chip size: 1 mm x 1 mm) operated at a forward current 20 mA at room temperature, the forward voltage and the light output power were measured to be 3.15 Vand 6.8 mW, respectively. Moreover, the light output power was greatly increased by 59% for the PSS flip-chip LED sample at a forward injection current of 350 mA. This result was attributed to increase in probability of escaping photons from the LEDs sample, resulting in the enhancement of light extraction efficiency.