Microstructure and field mapping of AlInN-based heterostructures and devices

Lin Zhou, David A. Cullen, Martha McCartney, Jacob H. Leach, Qian Fan, Hadis Morkoç, David Smith

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4 Scopus citations

Abstract

The microstructure, composition and electrostatic fields of near-lattice-matched Al1-xInxN/AlN/GaN heterostructures and devices have been characterized using a variety of electron microscopy techniques. A thin parastic Ga-rich layer was often observed immediately above the AlN spacer and was attributed to GaN nucleation during specimen cooling. Mapping of electrostatic potential profiles across a GaN/Al0.85In0.15N/AlN/ GaN heterostructure using off-axis electron holography showed polarization-induced fields of 7.5MV/cm within the AlN layer, and 2.2MV/cm within the Ga-rich layer. A two-dimensional electron gas with a density of ~9.8×1012 cm-2 was observed in the underlying GaN layer located very close to the AlN/GaN interface. Contact inclusions were observed extending into the AlInN and GaN layers along mixed-type threading dislocations under the source and drain regions of HFET devices. The density and size of the contact inclusions was determined by the annealing temperature.

Original languageEnglish (US)
Pages (from-to)2436-2439
Number of pages4
JournalPhysica Status Solidi (C) Current Topics in Solid State Physics
Volume7
Issue number10
DOIs
Publication statusPublished - Oct 2010

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Keywords

  • AlInN-based heterojunctions
  • Electron holography
  • Field-effect transistors
  • TEM

ASJC Scopus subject areas

  • Condensed Matter Physics

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