skip to main content

SciTech ConnectSciTech Connect

Title: Role of Fe impurity complexes in the degradation of GaN/AlGaN high-electron-mobility transistors

Recent experiments show that GaN/AlGaN high-electron-mobility transistors suffer from significant current collapse, which is caused by an increase in the concentration of traps with energy levels 0.5–0.6 eV below the conduction-band edge. This increase in trap concentration is consistent with thermally activated defect diffusion, but the responsible defect complexes have not been identified. It has been suggested that the defect complex may contain iron because of the proximity of the Fe-doped GaN substrate. Here, we report first-principles density-functional calculations of substitutional iron complexes, investigate their properties, and show that the Fe{sub Ga}-V{sub N} complex has properties that account for the observed degradation.
Authors:
 [1] ; ;  [2] ;  [1] ;  [3] ;  [3]
  1. Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States)
  2. Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, Tennessee 37235 (United States)
  3. (United States)
Publication Date:
OSTI Identifier:
22420278
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 5; Other Information: (c) 2015 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; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALUMINIUM COMPOUNDS; DENSITY FUNCTIONAL METHOD; DOPED MATERIALS; ELECTRON MOBILITY; ELECTRONIC STRUCTURE; ENERGY LEVELS; GALLIUM NITRIDES; IRON; IRON COMPLEXES; SUBSTRATES; TRANSISTORS