Low-resistance graded AlxGa1-xN buffer layers for vertical conducting devices on n-SiC substrates

Atsushi Nishikawa, Kazuhide Kumakura, Tetsuya Akasaka, Toshiki Makimoto

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

We investigated the Al composition and thickness dependence of the resistance of graded AlxGa1-xN buffer layers for vertical conducting devices on n-type 6H-SiC substrates. To measure current-voltage characteristics, a Ti/Au ohmic contact was formed on the backside of the SiC substrate. The Al composition of the buffer layer was varied from 2% to 10%. We found that the optimal buffer layer thickness for the lowest resistance decreases with increasing Al composition because the nucleation seeds on SiC substrate coalesce faster. Since the optimal layer thickness depends on the Al composition, the sheet Al concentration, which is calculated from the Al composition and the thickness, should be considered as a critical parameter for low buffer resistance of vertical conducting devices on n-SiC substrates.

Original languageEnglish
Pages (from-to)819-821
Number of pages3
JournalJournal of Crystal Growth
Volume298
Issue numberSPEC. ISS
DOIs
Publication statusPublished - 2007 Jan
Externally publishedYes

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low resistance
Buffer layers
buffers
conduction
Substrates
Chemical analysis
Ohmic contacts
Current voltage characteristics
Seed
seeds
electric contacts
Buffers
Nucleation
nucleation
electric potential

Keywords

  • A3. Metalorganic vapor phase epitaxy
  • B1. Nitrides
  • B3. Vertical conducting devices

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Low-resistance graded AlxGa1-xN buffer layers for vertical conducting devices on n-SiC substrates. / Nishikawa, Atsushi; Kumakura, Kazuhide; Akasaka, Tetsuya; Makimoto, Toshiki.

In: Journal of Crystal Growth, Vol. 298, No. SPEC. ISS, 01.2007, p. 819-821.

Research output: Contribution to journalArticle

Nishikawa, Atsushi ; Kumakura, Kazuhide ; Akasaka, Tetsuya ; Makimoto, Toshiki. / Low-resistance graded AlxGa1-xN buffer layers for vertical conducting devices on n-SiC substrates. In: Journal of Crystal Growth. 2007 ; Vol. 298, No. SPEC. ISS. pp. 819-821.
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