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Title: Remarkable changes in interface O vacancy and metal-oxide bonds in amorphous indium-gallium-zinc-oxide thin-film transistors by long time annealing at 250 °C

We have studied the effect of long time post-fabrication annealing on negative bias illumination stress (NBIS) of amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film-transistors. Annealing for 100 h at 250 °C increased the field effect mobility from 14.7 cm{sup 2}/V s to 17.9 cm{sup 2}/V s and reduced the NBIS instability remarkably. Using X-ray photoelectron spectroscopy, the oxygen vacancy and OH were found to exist at the interfaces of a-IGZO with top and bottom SiO{sub 2}. Long time annealing helps to decrease the vacancy concentration and increase the metal-oxygen bonds at the interfaces; this leads to increase in the free carrier concentrations in a-IGZO and field-effect mobility. X-ray reflectivity measurement indicated the increment of a-IGZO film density of 5.63 g cm{sup −3} to 5.83 g cm{sup −3} (3.4% increase) by 100 h annealing at 250 °C. The increase in film density reveals the decrease of O vacancy concentration and reduction of weak metal-oxygen bonds in a-IGZO, which substantially helps to improve the NBIS stability.
Authors:
; ;  [1]
  1. Advanced Display Research Center and Department of Information Display, Kyung Hee University, Seoul 130-701 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22395505
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 23; 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; ANNEALING; CARRIER MOBILITY; CONCENTRATION RATIO; FABRICATION; GALLIUM COMPOUNDS; ILLUMINANCE; INDIUM COMPOUNDS; INTERFACES; OXYGEN; REFLECTIVITY; SILICON OXIDES; STRESSES; THIN FILMS; TRANSISTORS; VACANCIES; X-RAY PHOTOELECTRON SPECTROSCOPY; ZINC OXIDES