Effect of physical densification on sub-gap density of states in amorphous InGaZnO thin films

Hyungon Oh, Kyoungah Cho, Sangsig Kim

Research output: Contribution to journalArticle

1 Citation (Scopus)


In this study, we investigate the relationship between the physical densification and sub-gap density-of-states (DOS) distribution of a-IGZO films prepared under various deposition pressures. For TFTs with a-IGZO channel films, the field effect mobility increases from 10.9 to 24.8 cm2/V·s, and the on-current increases from 1.5 to 20.8 μA as the deposition pressure for the channel films decreases from 7 to 1 mTorr. The sub-gap DOS distributions obtained from the electrical characteristics indicate the changes in the density of accepter-like tail states with deposition pressure. Further, the physical densification of the channel films increases as the deposition pressure decreases. Our study demonstrates that the lower density of accepter-like tail states and the higher physical densification contribute to the improved performance of a-IGZO TFTs.

Original languageEnglish
Pages (from-to)33-37
Number of pages5
JournalSuperlattices and Microstructures
Publication statusPublished - 2018 Sep 1



  • a-IGZO TFT
  • Density of states
  • Deposition pressure
  • Film density

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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