在軟性基板上研製具有奈米結構之薄膜氮化鎵發光二極體

Fabrication and characteristics of thin-film GaN-based light-emitting diodes with nanostructure on flexible substrate

邱崇安(Chung-An Chiou)

指導教授 ： 陳隆建

國立臺北科技大學/電資學院/光電工程系研究所/碩士(2013年)

https://doi.org/10.6841/NTUT.2013.00363

摘要

由於軟性電子元件與材料建置在可彎曲的基板上，相較於傳統的固態電子元件更具備了許多優點及應用的延伸性，近年來已成為新興科技的熱門話題，本研究的目的係要研製一種發光二極體基板轉移技術，使用具有可撓性質的軟性基板應用在氮化鎵發光二極體上。
實驗中利用有機金屬化學氣象沉積法(MOCVD)成長氮化鎵發光二極體(GaN-LED)，將LED和替代基板鍵合並且藉由雷射剝離(Laser lift off, LLO)的技術成功將藍寶石基板舉離，接著再將可撓式的不鏽鋼基板(Stainless steel foil, SSF)和LED結構鍵合並且利用導電銀膠當作黏著層達到歐姆接觸的效果，經過光激發螢光頻譜(Photoluminescence, PL)量測的結果顯示，其光激發光峰值波長分別位於365 nm以及450 nm，說明與氮化鎵材料能隙3.4 eV和激發藍光的現象相符，顯示在基板轉移後元件之發光波段範圍並無明顯變化，而電流電壓特性曲線下量測得到，在電流20 mA下其順向偏壓(forward voltage , VF)值為3.38 V，顯示置換基板後VF下降約4.8%，而透過彎曲的變化則可以進一步觀察到應力對多重量子井(MQW)的影響，間接導致元件的主要發光波長有藍位移現象產生。
此外，利用磁控濺鍍法搭配快速退火(RTA)成長鎳奈米球於元件表面上並以之為蝕刻遮罩，透過感應耦合式電漿蝕刻(Inductive Couple Plasma etcher, ICP)使得氮化鎵表面粗糙化，再將LED元件轉移至軟性基板後，經由光激發螢光量測發現蝕刻後藍光波長產生藍移變化，說明蝕刻有助於元件應力的釋放。

關鍵字

薄膜氮化鎵發光二極體 ； 雷射剝離 ； 晶圓鍵合 ； 光激發螢光 ； 彎曲 ； 感應耦合電漿蝕刻

並列摘要

Due to the more benefits with flexible substrate, this study is to research the technology of the fabrication of thin film GaN light emitting diodes (GaN LEDs) which transferred from sapphire to flexible substrate. In this projects, The LED structures were fabricated by using MOCVD and then it is separated from sapphire substrates by laser lift-off (LLO) after device bonding to substitute substrate. Then, the structure was transferred to stainless steel foil (SSF) and made the boundary ohmic contact by means of Ag glue. In addition, photoluminescence (PL) measurement demonstrates the emitting wavelength at 365 nm and 450 nm respectively which was no changed before and after transferring to flexible substrate and also manifested illuminating blue light. From current–voltage characteristics, the forward voltage had essential decrease to 3.38V about 4.8%. Besides, it was observed the impact of stress on multiple quantum well (MQW) was changed by bending and it also made the spectrum blue shift.
Over and above substrate transferring, it used RF reactive magnetron sputtering to grow Ni film and then forms Ni nanodot by rapid thermal annealing (RTA) above LED device so as to be the etching mask. By Inductive Couple Plasma (ICP) etching, it roughed GaN surface to release stress from the interior of LED which resulted in photoluminescence spectrum blue shift.

並列關鍵字

Thin-Film GaN LED ； Laser Lift Off ； Wafer Bonding ； Photoluminescence ； Bending ； Inductive Couple Plasma Etching

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