摘要 本論文針對覆晶發光二極體之高反射歐姆接觸電極，對元件熱穩定性影響，做一系列探討，發現傳統作法之覆晶發光二極體，熱穩定性不佳的原因是因為，p-type歐姆接觸電極與高反射金屬層，遇高溫後會相互擴散，因高反射金屬材料如Al、Ag皆為低功函數材料，當元件遇高溫時，高反射金屬材料向下擴散至p-type GaN表面由於與p-type功函數相差太大，接面處型成一個位障，故元件工作電壓因此升高；推知原因後吾人便提出利用製程的手法，將歐姆接觸電極與金屬高反射層區隔開，來改善熱穩定性問題最後再以ITO/SiO2/Al/SiO2組合之高反射歐姆電極製作元件，得到比傳統高反射歐姆電極Ni/Au/Al/Ti/Au製作之元件，高出約15%的反射率，故其外部量子效率，也比傳統高反射歐姆電極製作之覆晶發光二極體元件提升約1.5倍。 A light-emitting device comprises a multi-layer structure including one or more active layer configured to irradiate light in response to the application of an electric signal, a transparent passivation layer laid over an outmost surface of the multi-layer stack, a reflector layer laid over the passivation layer, and a plurality of electrode pads coupled with the multi-layer structure. In a manufacture process of the light-emitting device, the reflector layer and the passivation layer are patterned to form at least one opening exposing an area of the multi-layer structure. One electrode pad is formed through the opening of the reflector layer and the passivation layer to connect with the multi-layer structure.
