以光學鍍膜在藍綠光發光二極體上製作布拉格反射鏡之探討

Making distributed Bragg reflrctors on blue or green LED with optical thin film deposition

陳怡芳(Yi-Fang Chen)

指導教授 ： 陳念波

元智大學/電機通訊學院/電機工程學系/碩士(2011年)

https://doi.org/10.6838/YZU.2011.00271

摘要

本論文研製之藍綠光發光二極體是使用布拉格反射鏡方式於發光二極體背面進行光學鍍膜，成功地將8*11 mil藍光與16*16 mil綠光發光二極體於TO-CAN封裝後，提升亮度8~12%。本論文主要目的是利用布拉格反射鏡與金屬反射鏡將穿透藍寶石基板的光經過反射鏡再將光反射回來，使發光二極體元件具有較高的萃取效率結構，進而提升元件發光效率。在製作發光二極體元件之製程中，我們利用光學模擬軟體計算出布拉格反射鏡與金屬反射鏡之各膜層厚度，將達到反射率95%以上 ，但卻是最少層數的鍍膜厚度組設定為鍍膜參數，再利用離子束離子助鍍法之方式進行光學鍍膜，以提升元件亮度，實驗結果顯示使用布拉格反射鏡加上反射鏡發光二極體在光輸出功率皆優於SiO2加上反射鏡之發光二極體。

關鍵字

藍綠光發光二極體背面 ； 布拉格反射鏡 ； 金屬反射鏡 ； 光學鍍膜 ； 光學模擬軟體

並列摘要

In this thesis, we add the Distributed Bragg Reflector ( DBR ) technique and the metal mirror reflector to improve the external light output of the blue/green GaN-based light-emitting diodes. We deposit the DBR structures and metal mirror on wafer backside that successfully improve the light output efficiency about 8--12% for blue LEDs (8*11 mil) and green LEDs (16*16 mil) after package. The significant improvement can be attributed to the DBR structure which is highly reflective. In experiment, first we did the optical simulation to calculate the optimal reflector layer thickness and structures with the reflectivity of about 95%. After the reflector structure is defined, we use the ion-beam assisted deposition to get the highly reflective reflector on wafer backside. Finally, the result shows that the brightness of LED with DBR/metal reflector is higher than that with typical SiO2/metal reflector.

並列關鍵字

optical simulation ； blue/green GaN-based light-emitting diodes ； DBR structures ； metal mirror ； ion-beam assisted deposition

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