Investigations on Light Extraction Efficiency of GaN-Based Light-Emitting Diodes

• Main Authors: Yu-Shun Su, 蘇裕順
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/77572402740740419283

碩士 === 逢甲大學 === 資訊電機工程碩士在職專班 === 99 === This article researches the use of GaN epitaxial layer and the sapphire substrate to form the outer and inner chamfer of the morphology with the following two primary methodologies: First, coat barrier layer (SiO2) on flat substrates, define the type of SiO2 diagram by commencing the map with yellow litho process, and proceed with epitaxial process on the graphical SiO2 substrate. While the epitaxial layer is completed, remove the SiO2 between epitaxial and substrate to form the holes at the bottom of the epitaxial layer. Second, use wet etching process to etch the graphical R-Plane sapphire substrate as V-shaped, and then apply the exclusive epitaxy characteristic of MOCVD on C-Plane epitaxial layer to form the holes at the bottom of the epitaxial layer. The two methodologies mentioned above were proved to be able to form a number of holes between the epitaxial layer and the sapphire. After completion, application of lateral wet etching to etch the inside and outsides of the holes on the epitaxial layer would lead to the formation of chamfer morphology of the LED structure. Meanwhile, the structural change of the bottom and lateral sides of the LED will increase the odds of downward and leftward light emitting from the quantum well (MQW), and thus enhance the efficiency of LED light extraction.