Authors

D. I. Florescu; S. M. Ting; J. C. Ramer; D. S. Lee; V. N. Merai; A. Parkeh; D. Lu; E. A. Armour;L. Chernyak

Comments

"This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in the linked citation and may be found originally at Applied Physics Letters."

Abbreviated Journal Title

Appl. Phys. Lett.

Keywords

FILMS; GAN; Physics, Applied

Abstract

We have examined the nature of V-defects and inclusions embedded within these defects by atomic force microscopy (AFM) and high-resolution scanning electron microscopy (SEM)/ cathodoluminescence (CL) in InGaN/GaN multiple quantum wells (MQWs). To date, indium distribution nonuniformity in the well or GaN barrier growth temperature have been identified as the main factors responsible for the V-defect occurrence and propagation. Further complicating the matter, inclusions embedded within V-defects originating at the first InGaN-to-GaN interface have been observed under certain growth conditions. Our AFM and high-resolution SEM/CL findings provide evidence that some V-defects occur merely as direct results of barrier temperature growth, and that there are additional V-defects associated with In-rich regions, which act as sinks for further indium segregation during the MQW growth. Both types of V-defects have a tendency of promoting inclusions at low-temperature (800 degreesC) GaN barrier growth in an H-2-free environment. Localized strain-energy variations associated with the apex of V-defects may be responsible for the inclusion occurrence. Adding H-2 during the GaN barrier growth reduces V-defect formation and suppresses inclusion propagation entirely, rendering a uniform nanoscale CL signal.

Journal Title

Applied Physics Letters

Volume

83

Issue/Number

1

Publication Date

1-1-2003

Document Type

Article

Language

English

First Page

33

Last Page

35

WOS Identifier

WOS:000183877800012

ISSN

0003-6951

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