具不同蝕刻方式圖案化藍寶石基板上之氮化銦鎵類發光二極體

Abstract

成長在藍寶石基板上的氮化銦鎵類發光二極體，因磊晶層與藍寶石基板間的晶格常數不匹配以及熱膨脹係數的差異，使得元件內部產生量子侷限化史塔克效應，進而造成氮化銦鎵類發光二極體發光效率下降。因此，本篇論文將藉由不同蝕刻製程方法製作微結構圖案於藍寶石基板上，探討對氮化銦鎵類發光二極體造成的影響。吾人使用電子束微影系統搭配乾濕式蝕刻技術，製作出不同週期、相同深度與相同基板佔有比例的微結構於藍寶石基板上，並使用有機金屬化學氣相沉積系統進行氮化銦鎵類材料磊晶。其後，將使用拉曼光譜系統確認磊晶品質，光致激發螢光系統量測主動層發光特性，同時亦使用模擬軟體計算發光二極體的光萃取效率。

InGaN-based Light-Emitting Diodes (LEDs) are typically grown along c-plane sapphire substrates. The significant biaxial strain originated from the huge lattice mismatch between the InGaN active layer and the underlying GaN layer possesses piezoelectric electrical polarization; the intrinsic wurtzite crystal structure induces large spontaneous electric polarization as well. The total polarization fields result in quantum-confined Stark effect (QCSE). Therefore, the effects of the growths of InGaN-based materials on the patterned-sapphire substrates (PSSs) with different etching methods will be discovered in this thesis. The PSSs with various periodic square arrays, comprised the same depth, the same post-duty cycle, will be fabricated by conducting E-beam lithography system accompanied with different etching methods. After the epitaxial growth, to begin with, the constant-excitation power of micro-Raman (μ-Raman) system was utilized to provide comparison of the strain in the bulk layer. The samples were then characterized by the constant-excitation power of micro-photoluminescence (μ-PL) measurement to indentify the reduction in the internal field in the multiple quantum wells (MQWs). In addition, the light-extraction efficiency (LEE) of the PSSs was also simulated by the ray-tracing method using the Trace-Pro software.