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Title: Solution processed lanthanum aluminate gate dielectrics for use in metal oxide-based thin film transistors

We report on ZnO-based thin-film transistors (TFTs) employing lanthanum aluminate gate dielectrics (La{sub x}Al{sub 1−x}O{sub y}) grown by spray pyrolysis in ambient atmosphere at 440 °C. The structural, electronic, optical, morphological, and electrical properties of the La{sub x}Al{sub 1−x}O{sub y} films and devices as a function of the lanthanum to aluminium atomic ratio were investigated using a wide range of characterization techniques such as UV-visible absorption spectroscopy, impedance spectroscopy, spectroscopic ellipsometry, atomic force microscopy, x-ray diffraction, and field-effect measurements. As-deposited LaAlO{sub y} dielectrics exhibit a wide band gap (∼6.18 eV), high dielectric constant (k ∼ 16), low roughness (∼1.9 nm), and very low leakage currents (<3 nA/cm{sup 2}). TFTs employing solution processed LaAlO{sub y} gate dielectrics and ZnO semiconducting channels exhibit excellent electron transport characteristics with hysteresis-free operation, low operation voltages (∼10 V), high on/off current modulation ratio of >10{sup 6}, subthreshold swing of ∼650 mV dec{sup −1}, and electron mobility of ∼12 cm{sup 2} V{sup −1} s{sup −1}.
Authors:
;  [1] ; ; ;  [2] ;  [3] ;  [4] ;  [5]
  1. Engineering Department, Lancaster University, Lancaster LA1 4YR (United Kingdom)
  2. Physics Department, Lancaster University, Lancaster, LA1 4YB (United Kingdom)
  3. Physics Department, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)
  4. Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA (United Kingdom)
  5. (New Zealand)
Publication Date:
OSTI Identifier:
22402478
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 20; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; ABSORPTION SPECTROSCOPY; ALUMINATES; ALUMINIUM; ATOMIC FORCE MICROSCOPY; DIELECTRIC MATERIALS; ELECTRON MOBILITY; LANTHANUM COMPOUNDS; LEAKAGE CURRENT; PERMITTIVITY; PYROLYSIS; THIN FILMS; TRANSISTORS; ULTRAVIOLET SPECTRA; X-RAY DIFFRACTION; ZINC OXIDES