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 journalArticlepeer-review

    4 Citations (Scopus)

    Abstract

    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
    Volume121
    DOIs
    Publication statusPublished - 2018 Sept

    Bibliographical note

    Funding Information:
    This work was supported in part by the Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (No. NRF-2015R1D1A1A01057641 ), by Samsung Display Co. Ltd. , by the Brain Korea 21 Plus Project in 2018 , and by the Korea University Grant .

    Publisher Copyright:
    © 2018 Elsevier Ltd

    Keywords

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

    ASJC Scopus subject areas

    • General Materials Science
    • Condensed Matter Physics
    • Electrical and Electronic Engineering

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