Effect of buffer layer design on vertical GaN-on-GaN p-n and schottky power diodes

Houqiang Fu, Xuanqi Huang, Hong Chen, Zhijian Lu, Xiaodong Zhang, Yuji Zhao

Research output: Contribution to journalArticlepeer-review

46 Scopus citations


We study verticalGaN p-n and Schottky power diodes with different buffer layer thicknesses grown on free-standingGaN substrates, usingmetalorganic chemical vapor deposition. High breakdown voltage of > 1 kV and low specific on-resistance of 3 mω cm2 are achieved on GaN p-n diode with 1 μm buffer layer and 9 μm drift layer without passivation or field plate. Detailed device analysis on GaN Schottky diodes indicates that buffer layer has significant impacts on the electrical properties of drift layer and thus device performances of GaN p-n diodes. A thicker buffer layer will significantly enhance the breakdown voltages of these devices, which is possibly due to the improved material quality of drift layers with reduced defect densities. Higher doping concentration in drift layer with thicker buffer layer will, however, lower breakdown voltage. More discussions reveal improving the material quality of drift layer plays amore dominant role in achieving high breakdown GaN-on-GaN p-n and Schottky diodes with increasing buffer layer thickness.

Original languageEnglish (US)
Article number7891910
Pages (from-to)763-766
Number of pages4
JournalIEEE Electron Device Letters
Issue number6
StatePublished - Jun 2017


  • Gallium nitride
  • Schottky diodes
  • breakdown.
  • buffer layer
  • drift layer
  • p-n diodes
  • power electronics

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering


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