大面積次微米圖案藍寶石基板製作與磊晶技術開發

Abstract

圖案藍寶石基板增加LEDs發光亮度主要歸因於薄膜內部缺陷密度降低與光萃取效率提升，而照明市場的需求是高亮度及生產成本降低，倘若能發展低厚度平鋪次微米圖案藍寶石基板技術，縮短LED結構磊晶時間對於降低LEDs生產成本具有極大助益。在本計劃中我們將著重GaN薄膜磊晶成長的研究，並特別強調不同尺度圖案藍寶石基板之光學特性及晶體品質探討，其詳細內容茲分述如下： (1) 建立GaN薄膜磊晶最佳化之磊晶條件，擬利用PL、AFM、TEM及X光繞射頻譜量測表面平整度、缺陷密度及成長機制，並藉以調整磊晶參數以獲得最佳的成長條件。 (2) 低厚度平鋪次微米圖案藍寶石基板技術開發，維持光強度及晶體品質。

Enhancing the light brightness of InGaN/GaN LEDs using patterned sapphire substrate is mainly attributed to decreasing the dislocation density and light extraction efficiency. The demand of solid state lighting is high-brightness and prduction cost down. It will take advantage of decreasing LEDs production cost with shortening the epitaxy time of LED structure if we could develop low-thickness GaN film fabrication on submicro-patterned sapphire substrate. In this project, we claim to our research with special focuses on the studies of GaN epilayer growth, and of optical property of patterned sapphire subttrate with difffernt scales. The details are listed as follows: (1) Adjusting growth parameters including growth temperature, V/III ratio, input group gas ratio to optimize the growth conditions for GaN epilayer, in accord with the results of the following measurements, such as PL, AFM, SEM and X-ray diffraction spertrum. (2) Studying the optical brightness and crystalline quality of GaN epilayer with low-thickness fabrication on submicro-patterned sapphire substrate.