利用微米透鏡陣列與表面粗化加強垂直式氮化鎵發光二極體發光強度

Abstract

在本篇論文中，主要是探討垂直式氮化鎵發光二極體在表面製作微米透鏡陣列與表面粗化的製成技術與特性量測。在第一部分，我們利用雷射剝離技術成功的製做出垂直式氮化鎵發光二極體，並且在利用光阻溢流與乾式蝕刻將微米透鏡陣列製作在元件的表面，微米透鏡的尺寸為3、5、10、15、20微米，在量測的結果部分，在發光波長在460奈米下，垂直面的光增強了30%~15%相較於沒有製作微米透陣列的垂直式氮化鎵發光二極體。 另一部份，則是在垂直式氮化鎵發光二極體的表面製造粗化的效果，以來增進光從發光二極體中萃取出的效率，利用乾式蝕刻將表面製造出粗化的效果，再利用標準的黃光微影製成技術，因此成功的製造出n型表面粗化的垂直式氮化鎵發光二極體，至於出光強度的增強量會隨者表面粗化情況的不同有著30%∼110%的增強相較於沒有在表面製造粗化的垂直式氮化鎵光光二極體。

In the thesis, we report the GaN vertical light emitting diodes with micro lens array and surface roughening. The first part, GaN-based vertical light-emitting diodes (VLEDs) were fabricated by a laser lift-off (LLO) process and the effects of micro lens formation by plasma etching on GaN-based VLED devices were investigated. By forming a 3, 5, 10, 15 and 20um micro lens array on the GaN-based VLEDs, the measured light emission intensities at 460nm and in the direction normal to the surface of the device increased 30%~15% compared with those of the GaN-based VLED without the micro lens array. In second part, roughened surfaces of light emitting diodes provide substantial improvement in light extraction efficiency. By using the laser-lift-off technique followed by plasma etching process to roughen the surface, the VLEDs with n-GaN surface roughening has been fabricated. The enhancement of the VLED output power depends on the surface conditions. The output power of an optimally roughened surface VLED shows 30% to 110% increase compared to that of a conventional VLED.