觀察氮化銦鎵發光二極體逆偏電致發光特性與其可靠性之研究

Optical characterizations and reverse-bias electroluminescence observation for reliability investigations of the InGaN light emitting diode

廖泉豪(Chuan Hao Liao)

指導教授 ： 陳祥

國立暨南國際大學/科技學院/應用材料及光電工程學系/碩士(2013年)

https://doi.org/10.6837/NCNU.2013.00262

摘要

本研究結合偏壓與聚焦離子束量測(focused ion beam, FIB)、光學量測與電致發光及MATLAB圖像處理，來觀測藍光發光二極體氮化鎵 (gallinm nitride, GaN)表面逆偏發光情形。
我們對逆偏發光的表面有濃厚的興趣，現在人們對於發光二極體的發光缺陷還沒有完全的了解，為了加速測試時間，並迅速找到缺陷的GaN發光二極體（LED）。我們設計了一個壓力測試水蒸汽是工作在逆偏壓情況下，該樣品在室溫下的衰退是非常快的。經過200分鐘的暴露在水蒸汽的LED元件在能量散佈分析儀(energy dispersive X-ray spectrometer, EDX)分析和在掃瞄式電子顯微鏡(scanning electron, microscope, SEM)中的形態變化顯著，有著較高的氧分佈。電流 - 電壓曲線（I-V）被用來分析取得的臨界電壓和漏電流的電性。我們也進行了表面溫度測量和電致發光（electroluminescence, EL）通過Matlab圖像處理，找出漏電流和逆偏電壓發光之間的關係，再使用熱顯影的技術把逆偏電壓下的發光位置與漏電流所造成的高熱位置做比對，以及觀察到隨著水蒸氣在逆偏下的時間拉長，逆偏發光位置擴散的變化。這個研究描述一個衰退現象為元件損壞的檢測應用在未來的工業的製造技術。

關鍵字

發光二極體 ； 發光缺陷 ； 電致發光 ； 漏電流

並列摘要

This study combines bias measurements with a focused ion beam (FIB), optical measurements, electroluminescence and MATLAB, to observe light-emitting on the surface of the blue light emitting diodes nitrogen dioxide (Gallinm nitride, GaN) and blue light emitting diodes with indium gallium nitride (InGaN) under reverse bias. We have strong interested in reverse bias emitting, and people doesn’t fully understand light-emitting diodes emitting defects, in order to nimble and expedite testing time in operation, and indicate defect GaN light-emitting diode (LED) briefly. We schemed a stress test which is controlled in water vapor and under reverse-bias, the device degradation at room temperature is very quick. Under water vapor after 200 minute, the LEDs device exhibited remarkably higher oxygenation in EDX analysis and morphological variation in SEM compared to the other sample operated at normal atmosphere. Current-voltage curve (I-V) were used to make analysis of the electrical properties to acquire the threshold voltage and leakage current. We also deal with surface temperature measurement and 2D electroluminescence (EL) images via Matlab to ascertain the relation between leakage current and reverse-bias luminescence. These techniques were proposed to depict an actual optical degradation and detect the device defects with the fabrication process for future industrial applications.

並列關鍵字

Light emitting diodes ； Defects ； Electroluminescence ； Leakage current

參考文獻

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