Characteristics of ZnO epilayer on the post-annealed buffer layer on GaN/sapphire substrate by pulsed laser deposition

Tatsunori Sakano, Hiroki Fukuoka, Yoshihiro Yata, Toshiharu Saiki, Minoru Obara

    Research output: Contribution to journalArticle

    3 Citations (Scopus)

    Abstract

    We employed epi-GaN substrates for ZnO film growth, and studied the deposition and post-annealing effects. ZnO films were grown by pulsed laser deposition (PLD) method. The as-grown films were annealed for one hour under atmospheric pressure air. ZnO morphologies after annealing were investigated and the post-annealed ZnO films grown at T g =700oC have very smooth surfaces and the rms with roughness is about 0.5 nm. Finally, ZnO post-annealed buffer layer was inserted between ZnO epilayer and GaN/sapphire substrates. It is confirmed by AFM that growth temperature of 700oC helps the films grow in step-flow growth mode. It is observed by cathode luminescence spectrum that the ZnO film grown at 700oC has very low visible luminescence, indicating the decrease of the deep level defects. It is also revealed by Hall measurements that carrier concentration is decreased by increasing the growth temperatures. It is suggested that low temperature buffer layer growth and post-annealing technique can be used to fabricate ZnO hetero-epitaxy.

    Original languageEnglish
    Pages (from-to)697-703
    Number of pages7
    JournalApplied Physics A: Materials Science and Processing
    Volume93
    Issue number3
    DOIs
    Publication statusPublished - 2008 Nov 1

    ASJC Scopus subject areas

    • Chemistry(all)
    • Materials Science(all)

    Fingerprint Dive into the research topics of 'Characteristics of ZnO epilayer on the post-annealed buffer layer on GaN/sapphire substrate by pulsed laser deposition'. Together they form a unique fingerprint.

  • Cite this