氮化銦鎵/氮化鎵量子井雷射二極體之研製與分析

The Fabrication and Analysis of InGaN/GaN MQWs Laser Diode

呂政學(Cheng-Hsueh Lu)

指導教授 ： 綦振瀛

國立中央大學/資訊電機學院/電機工程學系/碩士(2006年)

摘要

摘要
本研究使用氮化鋁銦鎵系列之材料製作藍紫光（405nm）雷射二極體，內容著重在雷射二極體之研製、光場模擬與在臨界電流下的漏電流機制分析，共分為三個部份:
1. 雷射二極體結構與製程:以低成本、高品質的氮化鎵緩衝層作為基礎，利用氮化銦鎵覆蓋層來實現低P型歐姆接觸電阻，以及使用淺平台結構達成降低串聯電阻目的。
2. 模擬以氮化鋁鎵替代氮化鎵緩衝層，應用於（FIELO）橫向式成長法之緩衝層及氮化鎵基板之結構，改善光侷限因子。
3. 利用變溫光電流對應注入電流量測，分析接近於臨界電流下，自發性輻射複合電流及非輻射復合機制，其包括缺陷捕捉電荷漏電流、歐傑復合之漏電流在氮化鎵系列材料中形成原因，並提出降低其成分之方法。
最終提出結論，探討降低雷射二極體臨界電流方式，以臻至改善元件特性之目的。

關鍵字

非輻射複合 ； 雷射二極體 ； 氮化鎵

並列摘要

Abstract
This thesis presents the achievements reached in the development of InGaN/GaN multiple quantum well laser diodes on sapphire substrate.
1. Using an In0.3Ga0.7N capping layer and shallow mesa structure, which improves the p contact resistance to 9.58×10-5 Ωcm2 and the series resistance to 15 Ω at 100 mA, InGaN/GaN MQWs violet-blue laser diodes with a threshold current 9.4 kA/cm2 have been obtained.
2. It is shown that the confinement factor increases from 0.01 to 0.038 when replacing the GaN buffer layer with AlGaN for the lasers grown on a GaN substrate or a thick GaN template.
3. The monomolecular, radiative, and Auger recombination components of the injecting current are investigated for laser diodes grown on GaN buffers with different defect densities. It is found that the monomolecular recombination component dominates in these laser diodes due to the huge defect density. Besides, CHHL is found to be the main Auger recombination process of GaN-based lasers because the effective mass of light hole is extremely small compared to that of the spin-orbital split hole.

並列關鍵字

GaN ； laser diode ； non-radiative recombination

參考文獻

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