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Title: Semipolar (202{sup ¯}1) GaN and InGaN quantum wells on sapphire substrates

Here, we demonstrate a process to produce planar semipolar (202{sup ¯}1) GaN templates on sapphire substrates. We obtain (202{sup ¯}1) oriented GaN by inclined c-plane sidewall growth from etched sapphire, resulting in single crystal material with on-axis x-ray diffraction linewidth below 200 arc sec. The surface, composed of (101{sup ¯}1) and (101{sup ¯}0) facets, is planarized by the chemical-mechanical polishing of full 2 in. wafers, with a final surface root mean square roughness of <0.5 nm. We then analyze facet formation and roughening mechanisms on the (202{sup ¯}1) surface and establish a growth condition in N{sub 2} carrier gas to maintain a planar surface for further device layer growth. Finally, the capability of these semipolar (202{sup ¯}1) GaN templates to produce high quality device structures is verified by the growth and characterization of InGaN/GaN multiple quantum well structures. It is expected that the methods shown here can enable the benefits of using semipolar orientations in a scalable and practical process and can be readily extended to achieve devices on surfaces using any orientation of semipolar GaN on sapphire.
Authors:
; ; ; ; ; ; ;  [1] ; ;  [2]
  1. Department of Electrical Engineering, Yale University, New Haven, Connecticut 06520 (United States)
  2. Seoul Viosys Co., Ltd., Ansan City, Kyunggi-do 425-851 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22303892
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 26; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CARRIERS; CRYSTAL GROWTH; EQUIPMENT; GALLIUM NITRIDES; INDIUM COMPOUNDS; LAYERS; MECHANICAL POLISHING; MONOCRYSTALS; ORIENTATION; QUANTUM WELLS; ROUGHNESS; SAPPHIRE; SUBSTRATES; SURFACES; X-RAY DIFFRACTION