本論文主題是我們要探討AZO:Y 透明導電薄膜在不同摻雜濃度的As-grown 和As-etched n-GaN上歐姆接觸研究。藉由感應耦合離子蝕刻機ICP (Inductively coupled plasma, ICP)進行蝕刻，目的是在n-型氮化鎵上，將氧化物去除或是產生更多氮空缺，增加表面載子濃度可經由穿遂機制，促使良好的歐姆接觸[1]。AZO:Y 透明導電薄膜在n型氮化鎵上，在熱處理時歐姆特性會受到影響。當熱處理高於600C以上時，我們發現特徵電阻隨著溫度升高有變高趨勢。在熱處理AZO和p型氮化鎵是為了達到良好的歐姆接觸特性, 但熱處理溫度不能高於600C 。意謂著在應用氮化鎵發光二極體部分，我們可以將AZO薄膜同時成長在p型氮化鎵( p-GaN)和n型氮化鎵(n-GaN)並藉由改變薄膜在n型氮化鎵的電極形狀及AZO薄膜在n型氮化鎵上光撖取率，以增加光輸出功率。
此外我們籍由製程改變n型電極的幾何形狀去探討電流擴散分佈情況及光輸出功率。實驗結果，在光電特性方面在20mA注入下，AZO:Y指狀物電極結構和傳統電極結構的發光二極體上，其順向導通電壓(Vf)分別為3.47V與3.46V ，且其光輸出功率(Light output power)分別為2.31mW與2.39mW。兩者其導通電壓值接近，但其光輸出功率則增加了約3.5% 。

In this study, We focused on the mechanism for Ohmic contact of AZO:Y formation on as-grown and as etched differently doped n-GaN.The specific contact resistance of the AZO on n-GaN was reduced by the Cl2 plasma treatment on n-GaN in inductive coupled plasma etcher. The Cl2 plasma treatment on n-GaN might generate the nitrogen (N) vacancies on the surface of plasma damaged n-GaN layer and lead to reduce the specific contact resistance of the AZO on plasma damaged n-GaN layer.
The ohmic characteristics of the AZO on n-GaN could be affected by the thermal annealing. We found that the specific contact resistance would increase with increasing annealing temperature when the thermal annealing temperature higher than 600C
The annealing temperature to form a good ohmic contact of AZO on p-GaN was not higher than 600C. That means we could deposit the AZO on p-GaN and n-GaN at same time as the transparent contact of the n and p-type GaN of the LEDs
The light output power of the LED could be improved by changing pattern of the n-electrode and light extraction with AZO transparent n-contact. We use simple fabrication method and an innovative geometrical design on n type electrode pattern for GaN- based light-emitting diodes(LEDs) were investigated based on current spreading phenomenon and light output power .
GaN-based LEDs with conventional and AZO:Y finger light- emitting diodes(LEDs) were fabricated for the optoelectrical characteristics study. The forward voltage (light output power) was 3.46V (2.31mW) and 3.47 V (2.39mW) under 20mA current injection, respectively.
It was found that light output power was enhanced around 3.5%.

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