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Title: Effects of Ta incorporation in La{sub 2}O{sub 3} gate dielectric of InGaZnO thin-film transistor

The effects of Ta incorporation in La{sub 2}O{sub 3} gate dielectric of amorphous InGaZnO thin-film transistor are investigated. Since the Ta incorporation is found to effectively enhance the moisture resistance of the La{sub 2}O{sub 3} film and thus suppress the formation of La(OH){sub 3}, both the dielectric roughness and trap density at/near the InGaZnO/dielectric interface can be reduced, resulting in a significant improvement in the electrical characteristics of transistor. Among the samples with different Ta contents, the one with a Ta/(Ta + La) atomic ratio of 21.7% exhibits the best performance, including high saturation carrier mobility of 23.4 cm{sup 2}/V·s, small subthreshold swing of 0.177 V/dec, and negligible hysteresis. Nevertheless, excessive incorporation of Ta can degrade the device characteristics due to newly generated Ta-related traps.
Authors:
;  [1] ;  [2]
  1. Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road (Hong Kong)
  2. Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)
Publication Date:
OSTI Identifier:
22258602
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 12; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CARRIER MOBILITY; DIELECTRIC MATERIALS; LANTHANUM HYDROXIDES; LANTHANUM OXIDES; THIN FILMS; TRANSISTORS