Document Type

Article

Original Publication Date

2006

Journal/Book/Conference Title

Applied Physics Letters

Volume

89

Issue

26

DOI of Original Publication

10.1063/1.2423328

Comments

Originally published at http://dx.doi.org/10.1063/1.2423328

Date of Submission

April 2015

Abstract

The authors report a two-stage epitaxial lateral overgrowth (ELO) method to get uniformly coalesced (112¯0) a-plane GaN using metal organic chemical vapor deposition by employing a relatively lower growth temperature in the first stage followed by conditions leading to enhanced lateral growth in the second. Using a two-stage ELO method the average Ga-polar to N-polar wing growth rate ratio has been reduced from 4–6 to 1.5–2, which consequently reduced the height difference between the two approaching wings at the coalescence front that resulted from the wing tilt (0.44° for Ga and 0.37° for N wings, measured by x-ray diffraction), thereby making their coalescence much easier. Transmission electron microscopy showed that the threading dislocation density in the wing areas was 1.0×108cm−2, more than two orders of magnitude lower than that in the window areas (4.2×1010cm−2). However, high density of basal stacking faults of 1.2×104cm−1 was still present in the wing areas as compared to c-plane GaN where they are rarely observed away from the substrate. Atomic force microscopy and photoluminescence measurements on the coalesced ELOa-plane GaN sample also indicated improved material quality.

Rights

Ni, X., Özgür, Ü., Fu, Y., et al. Defect reduction in (112¯0) a-plane GaN by two-stage epitaxial lateral overgrowth. Applied Physics Letters, 89, 262105 (2006). Copyright © 2006 AIP Publishing LLC.

Is Part Of

VCU Electrical and Computer Engineering Publications

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