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Author Hayashi, Kazushi ♦ Hino, Aya ♦ Tao, Hiroaki ♦ Ochi, Mototaka ♦ Goto, Hiroshi ♦ Kugimiya, Toshihiro
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ ANNEALING ♦ ATOMS ♦ DEPOSITION ♦ DESORPTION ♦ ELECTRON EMISSION ♦ EMISSION SPECTROSCOPY ♦ EV RANGE 01-10 ♦ HYDROGEN ♦ HYDROGENATION ♦ SPECTRA ♦ SPECTROMETERS ♦ THIN FILMS
Abstract Total photoyield emission spectroscopy (TPYS) was applied to study the evolution of sub-gap states in hydrogen-treated amorphous In-Ga-Zn-O (a-IGZO) thin films. The a-IGZO thin films were subjected to hydrogen radicals and subsequently annealed in ultra-high vacuum (UHV) conditions. A clear onset of the electron emission was observed at around 4.3 eV from the hydrogen-treated a-IGZO thin films. After successive UHV annealing at 300 °C, the onset in the TPYS spectra was shifted to 4.15 eV, and the photoelectron emission from the sub-gap states was decreased as the annealing temperature was increased. In conjunction with the results of thermal desorption spectrometer, it was deduced that the hydrogen atoms incorporated in the a-IGZO thin films induced metastable sub-gap states at around 4.3 eV from vacuum level just after the hydrogenation. It was also suggested that the defect configuration was changed due to the higher temperature UHV annealing, and that the hydrogen atoms desorbed with the involvement of Zn atoms. These experiments produced direct evidence to show the formation of sub-gap states as a result of hydrogen incorporation into the a-IGZO thin films.
ISSN 00036951
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-09-14
Publisher Place United States
Journal Applied Physics Letters
Volume Number 107
Issue Number 11


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