Highly-stable and low-state-density Al2O3/GaN interfaces using epitaxial n-GaN layers grown on free-standing GaN substrates

• Kaneki, Shota

• Ohira, Joji

• Toiya, Shota

• Yatabe, Zenji

• Asubar, Joel T.

• Hashizume, Tamotsu

Abstract

Interface characterization was carried out on Al2O3/GaN structures using epitaxial n-GaN layers grown on free-standing GaN substrates with relatively low dislocation density (<3 x 10(6) cm(-2)). The Al2O3 layer was prepared by atomic layer deposition. The as-deposited metal-oxide-semiconductor (MOS) sample showed a significant frequency dispersion and a bump-like feature in capacitance-voltage (C-V) curves at reverse bias, showing high-density interface states in the range of 10(12) cm(-1) eV(-1). On the other hand, excellent C-V characteristics with negligible frequency dispersion were observed from the MOS sample after annealing under a reverse bias at 300 degrees C in air for 3 h. The reverse-bias-annealed sample showed state densities less than 1 x 10(11) cm(-1) eV(-1) and small shifts of flat-band voltage. In addition, the C-V curve measured at 200 degrees C remained essentially similar compared with the room-temperature C-V curves. These results indicate that the present process realizes a stable Al2O3/GaN interface with low interface state densities.

Journal

• Applied physics letters

  Applied physics letters 109 (16), 162104-1-162104-5, 2016-10-18

  American Institute of Physics (AIP)

Details

• CRID: 1050282813998458880
• NII Article ID: 120006360059
• NII Book ID: AA00543431
• HANDLE: 2115/67320
• ISSN: 00036951
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • CiNii Articles