Effects of low-temperature (120 °c) annealing on the carrier concentration and trap density in amorphous indium gallium zinc oxide thin film transistors

Jae Sung Kim, Byung Su Oh, Mingxing Piao, Min Kyu Joo, Ho Kyun Jang, Seung Eon Ahn, Gyu-Tae Kim

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Abstract

We report an investigation of the effects of low-temperature annealing on the electrical properties of amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs). X-ray photoelectron spectroscopy was used to characterize the charge carrier concentration, which is related to the density of oxygen vacancies. The field-effect mobility was found to decrease as a function of the charge carrier concentration, owing to the presence of band-tail states. By employing the transmission line method, we show that the contact resistance did not significantly contribute to the changes in device performance after annealing. In addition, using low-frequency noise analyses, we found that the trap density decreased by a factor of 10 following annealing at 120 °C. The switching operation and on/off ratio of the a-IGZO TFTs improved considerably after low-temperature annealing.

Original languageEnglish
Article number245302
JournalJournal of Applied Physics
Volume116
Issue number24
DOIs
Publication statusPublished - 2014 Jan 1

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ASJC Scopus subject areas

  • Physics and Astronomy(all)

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