Effect of Surface Treatment in Au/Ni/ n-GaN Schottky Contacts Formed on Cleaved m-Plane Surfaces of Free-Standing n-GaN Substrates

DOI Web Site 27 References
  • SHIOJIMA Kenji
    Graduate School of Electrical and Electronics Engineering, Faculty of Engineering, University of Fukui
  • IMABAYASHI Hiroki
    Graduate School of Electrical and Electronics Engineering, Faculty of Engineering, University of Fukui
  • MISHIMA Tomoyoshi
    Research Centre for Micro-Nano Technology, Hosei University

Bibliographic Information

Other Title
  • へき開した自立n-GaN基板の<i>m</i>面に形成したAu/Niショットキー接触における表面処理の影響

Abstract

<p>We fabricated and characterized Au/Ni Schottky contacts on cleaved m-plane free-standing n-GaN surfaces (i) without any surface treatment, (ii) with H2O2 treatment, or (iii) with HCl treatment by current-voltage (I-V), capacitance-voltage (C-V), and photoresponse (PR) measurements. 50-nm-thick Ni films and 50-nm-thick Au films were deposited in turn on the m-plane surface by electron-beam evaporation to form Schottky contacts. All of the Schottky contacts were circular and 100µm in diameter. The highest step determined by the laser microscope was 5 nm, but in some dots, steps were not observed. The as-cleaved samples showed I-V characteristics with small n-values and less diode-to-diode variation. However, the H2O2 samples had much smaller Schottky barrier height (qϕB). Whereas the HCl samples exhibited significantly large diode-to-diode variation. The qϕB and n-values obtained from the I-V, C-V, and PR results are nearly constant, independent of the step height. This is probably because the steps also consist of m-plane facets, which have no effect on the electrical characteristics of the Schottky diodes. It is confirmed that cleaving without any surface treatment can provide a cleaner surface to form Schottky diodes on m-plane n-GaN surfaces than that with conventional HCl treatment.</p>

Journal

References(27)*help

See more

Related Projects

See more

Keywords

Details 詳細情報について

Report a problem

Back to top