標題: Reduction of Defects in AlGaN Grown on Nanoscale-Patterned Sapphire Substrates by Hydride Vapor Phase Epitaxy
作者: Tasi, Chi-Tsung
Wang, Wei-Kai
Tsai, Tsung-Yen
Huang, Shih-Yung
Horng, Ray-Hua
Wuu, Dong-Sing
電子工程學系及電子研究所
Department of Electronics Engineering and Institute of Electronics
關鍵字: AlGaN;hydride vapor phase epitaxy (HVPE);nanoscale-patterned sapphire substrate (NPSS);dislocation density (TD)
公開日期: 1-Jun-2017
摘要: In this study, a 3-m-thick AlGaN film with an Al mole fraction of 10% was grown on a nanoscale-patterned sapphire substrate (NPSS) using hydride vapor phase epitaxy (HVPE). The growth mechanism, crystallization, and surface morphology of the epilayers were examined using X-ray diffraction, transmission electron microscopy (TEM), and scanning electron microscopy at various times in the growth process. The screw threading dislocation (TD) density of AlGaN-on-NPSS can improve to 1-2 x 10(9) cm(-2), which is significantly lower than that of the sample grown on a conventional planar sapphire substrate (7 x 10(9) cm(-2)). TEM analysis indicated that these TDs do not subsequently propagate to the surface of the overgrown AlGaN layer, but bend or change directions in the region above the voids within the side faces of the patterned substrates, possibly because of the internal stress-relaxed morphologies of the AlGaN film. Hence, the laterally overgrown AlGaN films were obtained by HVPE, which can serve as a template for the growth of ultraviolet III-nitride optoelectronic devices.
URI: http://dx.doi.org/10.3390/ma10060605
http://hdl.handle.net/11536/145729
ISSN: 1996-1944
DOI: 10.3390/ma10060605
期刊: MATERIALS
Volume: 10
Issue: 6
起始頁: 0
結束頁: 0
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