設施農業：節能栽培與滅菌【材料科學與工程學系武東星教授】

論文篇名 英文：Structural and Stress Properties of AlGaN Epilayers Grown on AlN-Nanopatterned Sapphire Templates by Hydride Vapor Phase Epitaxy
中文：藉由氫化物氣相磊晶法在AlN-奈米圖案藍寶石模板上成長AlGaN磊晶並探討其結構與應力特性
期刊名稱 Nanomaterials
發表年份,卷數,起迄頁數 2018, 8, 704
作者 Chi-Tsung Tasi , Wei-Kai Wang , Sin-Liang Ou , Shih-Yung Huang , Ray-Hua Horng and Dong-Sing Wuu*(武東星)
DOI 10.3390/nano8090704
中文摘要 本文中利用氫化物氣相磊晶法於AlN /奈米圖案藍寶石基板（NPSS）基板表面進行AlGaN（Al佔摩爾比10％）磊晶成長並探討其材料特性。使用X射線繞射（XRD），原子力顯微鏡（AFM）和透射電子顯微鏡（TEM）研究AlGaN / AlN / NPSS磊晶層的結晶品質，表面形態，微觀結構和應力狀態。結果表示，當在AlN / NPSS基板上成長時，可改善AlGaN膜的結晶品質。對於在AlN / NPSS基板上生長的AlGaN磊晶層，螺紋穿透位錯（TD）密度降低至1.4×109，低於在平坦的c-平面藍寶石襯底上生長的樣品（6.3× 109 cm- 2）。通過XRD測量檢驗，AlGaN膜的雙軸拉伸應力從1,187 MPa（在AlN / NPSS表面上）顯著降低至38.41MPa（在平坦的c面藍寶石表面上）。特別地，通過TEM觀察證實過度成長的AlGaN層中Al含量增加。這可能透過AlGaN和AlN / NPSS基板界面釋放面內應力。
英文摘要 In this paper, we report the epitaxial growth and material characteristics of AlGaN (Al mole fraction of 10%) on an AlN/nanopatterned sapphire substrate (NPSS) template by hydride vapor phase epitaxy (HVPE). The crystalline quality, surface morphology, microstructure, and stress state of the AlGaN/AlN/NPSS epilayers were investigated using X-ray diffraction (XRD), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The results indicate that the crystal quality of the AlGaN film could be improved when grown on the AlN/NPSS template. The screw threading dislocation (TD) density was reduced to 1.4×109 cm-2 for the AlGaN epilayer grown on the AlN/NPSS template, which was lower than that of the sample grown on a flat c-plane sapphire substrate (6.3×109 cm- 2). As examined by XRD measurements, the biaxial tensile stress of the AlGaN film was significantly reduced from 1,187 MPa (on AlN/NPSS) to 38.41 MPa (on flat c-plane sapphire). In particular, an increase of the Al content in the overgrown AlGaN layer was confirmed by the TEM observation. This could be due to the relaxation of the in-plane stress through the AlGaN and AlN/NPSS template interface.