垂直式發光二極體以晶圓鍵結(Wafer bonding)，以及雷射剝離(Laser lift-off)製程，將元件轉置於導熱與導電性良好之矽基板，因此垂直式發光二極體為高亮度，高耐熱之長效性發光二極體。而從n型電極配置的型態分為平台式(Flat Platform n-electrode)與嵌入式電極(Ember Platform n-electrode)兩種，平台式電極結構為使用感應式耦合電漿(ICP)將未經摻雜之氮化鎵(u-GaN)移除，有效發光區域以除了n型電極以外的n型氮化鎵(n-GaN)為發光表面，而嵌入式電極結構在n型電極下方使用ICP將未經摻雜之氮化鎵(u-GaN) 移除，其他區域則露出未經摻雜之氮化鎵，因此有效發光區域以除了n型電極以外的未經摻雜之氮化鎵(u-GaN)為發光表面。本論文針對上述兩種結構進行不同時間氫氧化鉀(KOH)化學表面粗化(Surface Roughness)製程，探討粗化蝕刻n型氮化鎵(n-GaN)和未經摻雜之氮化鎵(u-GaN)之光電特性分析。
平台式與嵌入式電極結構皆隨粗化蝕刻時間增加，而提升光輸出功率(Light output power)、外部量子效率(External Quantum Efficiency,EQE)。隨粗化蝕刻時間增加至20 分鐘，平台式電極結構產生過蝕現象使元件之順向偏壓(Vf)、逆偏漏電流（Leakage Current）提高、形成電流擁擠效應(Current crowding)、以及發光波長藍移，上述問題於嵌入式電極結構將獲得改善。

The Vertical light-emitting diodes was bonded on silicon substrate by wafer bonding and Laser lift-off process. This process transfer LED Epitaxial structure to silicon substrate with good thermal conductivity and electrical conductivity, so that vertical light-emitting diodes is long live light-emitting diodes which have high brightness and high heat stability characteristic. In this article, there are two type of n-type electrode configuration, One is “Flat Platform n-electrode” and the other is “Ember Platform n-electrode”. “Flat Platform n-electrode” use inductive coupled plasma (ICP) to etch intrinsic Gallium-Nitride (u-GaN), so the effective light emitting area is n-type Gallium-Nitride (n-GaN) surface, otherwise n-electrode area. “Ember Platform n-electrode ” use inductive coupled plasma(ICP) to etch intrinsic Gallium-Nitride(u-GaN) which in n-electrode area , so the effective light emitting area is intrinsic Gallium-Nitride (u-GaN) surface, otherwise n-electrode area. In this article, the two kind of n-electrode structure of vertical light emitting diode used different etching times by potassium hydroxide (KOH) in chemical surface roughening (Surface Roughness) process, and discuss the optical and electrical characterization of the surface roughness process in n-type Gallium-Nitride (n-GaN) and intrinsic Gallium-Nitride (u-GaN).
As the increasing of the etching time, both “Ember Platform n-electrode” and “Flat Platform n-electrode” are more and more rough, and enhance the light output power, the external quantum efficiency (EQE). With the etching time increased to 20 min, “Flat Platform n-electrode” structure have over etching phenomenon which is forward voltage(Vf) increasing, and reverse leakage current(Ir) increasing. And then, It cause current crowding effects, and a light emitting wavelength blue shift. We can solve above problem by using “Ember Platform n-electrode” structure.

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