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Title: Deep-level transient spectroscopy on an amorphous InGaZnO{sub 4} Schottky diode

The first direct measurement is reported of the bulk density of deep states in amorphous IGZO (indium-gallium-zinc oxide) semiconductor by means of deep-level transient spectroscopy (DLTS). The device under test is a Schottky diode of amorphous IGZO semiconductor on a palladium (Pd) Schottky-barrier electrode and with a molybdenum (Mo) Ohmic contact at the top. The DLTS technique allows to independently measure the energy and spatial distribution of subgap states in the IGZO thin film. The subgap trap concentration has a double exponential distribution as a function energy, with a value of ∼10{sup 19} cm{sup −3} eV{sup −1} at the conduction band edge and a value of ∼10{sup 17} cm{sup −3} eV{sup −1} at an energy of 0.55 eV below the conduction band. Such spectral distribution, however, is not uniform through the semiconductor film. The spatial distribution of subgap states correlates well with the background doping density distribution in the semiconductor, which increases towards the Ohmic Mo contact, suggesting that these two properties share the same physical origin.
Authors:
; ; ; ;  [1] ;  [2] ;  [1] ;  [2] ;  [3]
  1. imec, Kapeldreef 75, 3001 Leuven (Belgium)
  2. (Belgium)
  3. ESAT, KU Leuven, Kasteelpark Arenberg 10, 3001 Leuven (Belgium)
Publication Date:
OSTI Identifier:
22293050
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 8; 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; BULK DENSITY; CONCENTRATION RATIO; DEEP LEVEL TRANSIENT SPECTROSCOPY; ELECTRODES; ENERGY DEPENDENCE; GALLIUM OXIDES; INDIUM OXIDES; MOLYBDENUM; PALLADIUM; SCHOTTKY BARRIER DIODES; SEMICONDUCTOR MATERIALS; SPATIAL DISTRIBUTION; THIN FILMS; ZINC OXIDES