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Title: Effects of threading dislocations on drain current dispersion and slow transients in unpassivated AlGaN/GaN/Si heterostructure field-effect transistors

Current transient analysis combined with response to pulsed bias drives have been used to explore the possibilities of threading dislocations affecting the current dispersion characteristics of AlGaN/GaN heterostructure field-effect transistors (HFETs). A growth strategy is developed to modulate the dislocation density among the heterostructures grown on silicon by plasma-assisted molecular-beam epitaxy. Slow pulsed I-V measurements show severe compressions and appear to be significantly dependent on the threading dislocation density. By analyzing the corresponding slow detrapping process, a deep-level trap with emission time constant in the order of seconds was identified as the cause. Among the specimens, both in the epilayers and at the surface, the number of dislocations was found to have a notable influence on the spatial distribution of deep-level trap density. The observations confirm that the commonly observed degraded frequency performance among AlGaN/GaN HFETs in the form of DC-radio frequency dispersions can at least partly be correlated with threading dislocation density.
Authors:
; ; ; ; ;  [1] ;  [2] ;  [3] ;  [1] ;  [4]
  1. Advanced Technology Development Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)
  2. Department of E and E C E, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)
  3. Department of Material Science and Engineering, National Chiao Tung University, Hsinchu 30050, Taiwan (China)
  4. (India)
Publication Date:
OSTI Identifier:
22310917
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 7; 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; ALUMINIUM COMPOUNDS; CRYSTAL GROWTH; CURRENTS; DISLOCATIONS; ELECTRIC CONDUCTIVITY; EMISSION; FIELD EFFECT TRANSISTORS; GALLIUM NITRIDES; MOLECULAR BEAM EPITAXY; PULSES; RADIOWAVE RADIATION; SILICON; SPATIAL DISTRIBUTION; SURFACES; TRANSIENTS; TRAPS