Extrinsic base regrowth of p-InGaN for Npn-type GaN/InGaN heterojunction bipolar transistors

Toshiki Makimoto*, Kazuhide Kumakura, Naoki Kobayashi

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

23 Citations (Scopus)


The regrowth of p-InGaN as the extrinsic base layer of Npn-type GaN/InGaN heterojunction bipolar transistors (HBTs) significantly improves the ohmic characteristics of the base layer. The specific contact resistance is 7.8 × 10-4 Ω-cm2 even after the dry etching. This value for a non-alloyed ohmic contact is much better than that for as-grown p-GaN (1.7 × 10-3 Ω-cm2) and decreased turn-on voltage in the emitter-base diodes, which results in high current gains of up to 2000 and reduced offset voltages in the GaN/InGaN HBTs. These results show that the p-InGaN extrinsic base regrowth is an effective way to improve nitride HBT characteristics.

Original languageEnglish
Pages (from-to)1922-1924
Number of pages3
JournalJapanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
Issue number4 B
Publication statusPublished - 2004 Apr
Externally publishedYes


  • Contact resistance
  • Current gain
  • Diode
  • Extrinsic base
  • HBT
  • Offset voltage
  • Ohmic contact
  • P-InGaN
  • Regrowth

ASJC Scopus subject areas

  • Engineering(all)
  • Physics and Astronomy(all)


Dive into the research topics of 'Extrinsic base regrowth of p-InGaN for Npn-type GaN/InGaN heterojunction bipolar transistors'. Together they form a unique fingerprint.

Cite this