Critical electric fields of AlGaN in AlGaN-based vertical conducting diodes on n-SiC substrates

Atsushi Nishikawa*, Kazuhide Kumakura, Tetsuya Akasaka, Toshiki Makimoto

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)


We have succeeded in obtaining high critical electric fields from AlGaN layers using the p-InGaN/i-AlxGa1-xN/n-AlxGa1-xN (x = 0 - 0.22) vertical conducting diodes grown on n-SiC substrates by low-pressure metalorganic vapor phase epitaxy (MOVPE). The breakdown voltage (VB) increases with increasing Al composition of the AlGaN layer. The corresponding critical electric fields are calculated to be 2.4 MV/cm for GaN and 3.5 MV/cm for Al0.22Ga0.78N. The critical electric field is proportional to the bandgap energy to a power of 2.5. This bandgap energy dependence is much stronger than that in the empirical expression proposed by Sze and Gibbons. The figure of merit, (VB)2 / Ron, increases with increasing Al composition, indicating the AlGaN-based p - i - n diodes are promising for high-power and high-temperature electronic device applications.

Original languageEnglish
Pages (from-to)332-337
Number of pages6
JournalSuperlattices and Microstructures
Issue number4-6 SPEC. ISS.
Publication statusPublished - 2006 Oct
Externally publishedYes


  • AlGaN
  • Critical electric field
  • Vertical conducting diode

ASJC Scopus subject areas

  • General Materials Science
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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