本實驗主要是利用不同的化學溶液與藍寶石(sapphire)基材間反應情況的不同藉由溼式蝕刻的方式在藍寶石基材上進行表面粗化， 並探討不同的蝕刻溶液、溫度及時間下對藍寶石基材的蝕刻深度和表面形貌的影響。 我們選取其中一種蝕刻參數所得的形貌應用於傳統發光二極體結構(conventional LED structure) 此種技術即稱為圖案化之藍寶石基材(pattern sapphire substrate)。 又因本實驗不同於以往利用微影製程(lithography)的技術所得之一規律的圓形、方形、長條等規則形狀而是直接利用不同參數的蝕刻液所得的金字塔錐、六角形等圖案，所以又稱此技術為自然圖案化之藍寶石基材(nature pattern sapphire substrate)。 利用此一技術所製得之conventional LED 藉PL、 XRD 來鑑定GaN film quality 以及LIV curve探討此技術對電性和光性的影響。 We do the surface texture on sapphire substrate by wet etching due to degree of reaction between sapphire and etching solution. In this experiment, we use different kinds of etching solution, temperature and time to etch C-plane sapphire surface and investigate the relationship between the etching parameter and etching morphology. We choose one kind of the etching morphology and apply to do conventional LED structure and so call the pattern sapphire substrate. Instead of the conventional way to do the pattern sapphire substrate by lithography to get the regular shape like cylinder, square, pillar and so on we etch sapphire surface by wet etching directly to get pyramid, hexagon shape and so on so called this new way to be the nature pattern sapphire substrate. By the way doing the PL and XRD to analysis the GaN film quality and investigate electric and photo characteristic by LIV curve when process into conventional LED structure.
