skip to main content

SciTech ConnectSciTech Connect

Title: Multicharacterization approach for studying InAl(Ga)N/Al(Ga)N/GaN heterostructures for high electron mobility transistors

We report on our multi–pronged approach to understand the structural and electrical properties of an InAl(Ga)N(33nm barrier)/Al(Ga)N(1nm interlayer)/GaN(3μm)/ AlN(100nm)/Al{sub 2}O{sub 3} high electron mobility transistor (HEMT) heterostructure grown by metal organic vapor phase epitaxy (MOVPE). In particular we reveal and discuss the role of unintentional Ga incorporation in the barrier and also in the interlayer. The observation of unintentional Ga incorporation by using energy dispersive X–ray spectroscopy analysis in a scanning transmission electron microscope is supported with results obtained for samples with a range of AlN interlayer thicknesses grown under both the showerhead as well as the horizontal type MOVPE reactors. Poisson–Schrödinger simulations show that for high Ga incorporation in the Al(Ga)N interlayer, an additional triangular well with very small depth may be exhibited in parallel to the main 2–DEG channel. The presence of this additional channel may cause parasitic conduction and severe issues in device characteristics and processing. Producing a HEMT structure with InAlGaN as the barrier and AlGaN as the interlayer with appropriate alloy composition may be a possible route to optimization, as it might be difficult to avoid Ga incorporation while continuously depositing the layers using the MOVPE growth method. Our present work shows the necessity ofmore » a multicharacterization approach to correlate structural and electrical properties to understand device structures and their performance.« less
Authors:
;  [1] ; ; ;  [2] ; ; ;  [3] ; ; ;  [4] ; ; ;  [5] ; ;  [6] ;  [7] ;  [8]
  1. Dept of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom)
  2. CIMAP UMR 6252 CNRS-ENSICAEN-CEA-UCBN 14050 Caen Cedex (France)
  3. Dipartimento di Fisica Astronomia, Università di Bologna, 40127 Bologna (Italy)
  4. Institute of Solid State Physics, Technical University Berlin, 10623 Berlin (Germany)
  5. AIXTRON SE, Kaiserstr. 98, 52134 Herzogenrath (Germany)
  6. Thales Research and Technology, III-V Lab, 91460 Marcoussis (France)
  7. LPN, Route de Nozay, 91460 Marcoussis (France)
  8. Institut des NanoSciences, Université Pierre et Marie Curie, 75015 Paris (France)
Publication Date:
OSTI Identifier:
22420189
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 4; Journal Issue: 12; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALLOYS; ALUMINIUM NITRIDES; ALUMINIUM OXIDES; DEPOSITS; DIFFUSION BARRIERS; ELECTRICAL PROPERTIES; ELECTRON MOBILITY; GALLIUM NITRIDES; ORGANOMETALLIC COMPOUNDS; SIMULATION; SPECTROSCOPY; TRANSISTORS; TRANSMISSION ELECTRON MICROSCOPY; VAPOR PHASE EPITAXY