Control and characterization of ZnO/GaN heterointerfaces in plasma-assisted MBE-grown ZnO films on GaN/Al2O3

Soon Ku Hong, Hang Ju Ko, Yefan Chen, Takashi Hanada, Takafumi Yao

Research output: Contribution to journalConference articlepeer-review

33 Citations (Scopus)


We report control of ZnO/GaN heterointerface by employing pre-treatments prior to ZnO films growth. Interface layer formation at ZnO/GaN heterointerface and control of interface layer formation was investigated. Interface layer was formed by first oxygen pre-exposure about 2-8 min to the Ga face (0001) GaN/sapphire substrate. The interface layer was observed directly by high-resolution transmission electron microscopy (HRTEM) and identified as a single crystalline monoclinic Ga2O3. ZnO film on the interface layer was single crystal. The formation of the oxide interface layer was prevented by first pre-exposure of zinc. Over-exposure (about 15 min) to oxygen plasma results in amorphous layer evaluated by reflection high-energy electron diffraction (RHEED) observation. Even on this surface, further ZnO films were grown as a single crystal as confirmed by RHEED and HRTEM observations. However, amorphous layer on the top of the interface layer was not observed by HRTEM. We concluded that the amorphous layer might be transformed to crystalline layer during ZnO growth by solid phase epitaxy.

Original languageEnglish
Pages (from-to)441-448
Number of pages8
JournalApplied Surface Science
Publication statusPublished - 2000 Jan 1
Event3rd International Symposium on the Control of Semiconductor Interfaces (ISCSI-3) - Karuizawa, Jpn
Duration: 1999 Oct 251999 Oct 29

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics
  • Physics and Astronomy(all)
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films


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