Effect of the Ammonia Flow on the Formation of Microstructure Defects in GaN Layers Grown by High-Temperature Vapor Phase Epitaxy

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• 作者：M. Barchuk ; G. Lukin ; F. Zimmermann ; C. Röder…
• 关键词：GaN layers ; microstructure defects ; photoluminescence ; x ; ray diffraction ; transmission electron microscopy ; micro ; Raman spectroscopy
• 刊名：Journal of Electronic Materials
• 出版年：2017
• 出版时间：March 2017
• 年：2017
• 卷：46
• 期：3
• 页码：1612-1619
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Optical and Electronic Materials; Characterization and Evaluation of Materials; Electronics and Microelectronics, Instrumentation; Solid State Physics;
• 出版者：Springer US
• ISSN：1543-186X
• 卷排序：46

文摘

High-temperature vapor phase epitaxy (HTVPE) is a physical vapor transport technology for a deposition of gallium nitride (GaN) layers. However, little is known about the influence of the deposition parameters on the microstructure of the layers. In order to fill this gap, the influence of the ammonia (NH₃) flow applied during the HTVPE growth on the microstructure of the deposited GaN layers is investigated in this work. Although the HTVPE technology is intended to grow GaN layers on foreign substrates, the GaN layers under study were grown on GaN templates produced by metal organic vapor phase epitaxy in order to be able to separate the growth defects from the defects induced by the lattice misfit between the foreign substrate and the GaN layer. The microstructure of the layers is characterized by means of high-resolution x-ray diffraction (XRD), transmission electron microscopy and photoluminescence. In samples deposited at low ammonia flow, planar defects were detected, along which the nitrogen atoms are found to be substituted by impurity atoms. The interplay between these planar defects and the threading dislocations is discussed. A combination of XRD and micro-Raman spectroscopy reveals the presence of compressive residual stress in the samples.