Strained thick p-InGaN layers for GaN/InGaN heterojunction bipolar transistors on sapphire substrates

Toshiki Makimoto, Yoshiharu Yamauchi, Jakatoshi Kido, Kazuhide Kumakura, Yoshitaka Taniyasu, Makoto Kasu, Nobuo Matsumoto

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5 Citations (Scopus)


Thick p-InGaN layers were grown on GaN by metalorganic vapor phase epitaxy to investigate the strain inside p-InGaN using a reciprocal space map of X-ray diffraction intensity, It was found that a large part of p-InGaN grows coherently on the GaN buffer layer, even though it is much thicker than the calculated critical thickness. This result means that few dislocations are generated at the InGaN/GaN interface. Using this strained thick p-InGaN as a base, a GaN/InGaN heterojunction bipolar transistor was fabricated on a sapphire substrate. Its maximum current gain was as high as 1000 and its offset voltage as low as 0.2V, which matches that calculated from the conduction-band discontinuity between the n-GaN emitter and the p-InGaN base.

Original languageEnglish
Pages (from-to)2722-2725
Number of pages4
JournalJapanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
Issue number4 B
Publication statusPublished - 2005 Apr
Externally publishedYes



  • Current gain
  • GaN
  • GaN/InGaN
  • HBT
  • Offset voltage
  • P-InGaN
  • Sapphire substrate
  • Strain

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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