The Study of The GaN-Based Nano-Structure by Inductively Coupled Plasma

• Main Authors: Yu-Hsien Shan, 沈育賢
• Other Authors: Yan-Kuin Su
• Format: Others
• Language: en_US
• Online Access: http://ndltd.ncl.edu.tw/handle/88156778188511899536

碩士 === 國立成功大學 === 光電科學與工程研究所 === 96 === Recently, III-nitride wide bandgap materials have aroused considerable interests due to various applications, such as traffic signals, back-side lighting in liquid crystal display, illumination lighting by white light emitting diodes (LEDs), and so on. However, the light extraction efficiency of GaN LEDs is not ideal to take place of the fluorescent light. This problem is mainly for the differences of refractive indices between the GaN and air. Therefore, the critical angle for the interface is about 23o from Snell’s law under the room temperature. Therefore, it makes a great fraction of light unable to emit into the air. In my experiment, I want to increase the GaN surface roughness in order to enhance the probability of photon passing through air and solve the light extraction efficiency problem. So the nano-structure which increases GaN surface roughness could be used to improve light extraction efficiency. The purposes of research nano-sturecute are many applications such as LEDs, field emitters, flat-panel displays, patterned sapphire substrate (PSS) and so on. I mainly focus on how to obtain the GaN nano-structure in my experiment. The methods for GaN nano-structure are directly and indirectly etching methods. The latter technique is the improvement of the former one. And the nano-structure by indirectly method could be easily controlled the diameter and density for this structure. Finally, I fabricate the devices with GaN nano-structure. And it successfully enhances the light extraction efficiency 80.5%.