InAs-inserted-channel InAlAs/InGaAs inverted HEMTs with direct ohmic contacts

Tatsushi Akazaki, Hideaki Takayanagi, Junsaku Nitta, Takatomo Enoki

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


We have investigated the device characteristics of InAs-inserted-channel In0.52Al0.48As/In0.53Ga0.47As inverted high electron mobility transistors (HEMTs) with a novel ohmic structure. The ohmic contact between the ohmic electrodes and the two-dimensional electron gas (2DEG) formed in the InAs layer is obtained by direct contact with the ohmic electrodes-InAs, instead of an alloyed normal-metal and semiconductor as in a conventional inverted HEMT. The contact resistance of 0.11 Ωmm between the ohmic electrodes and the channel is smaller by a factor of 4, than that obtained using a conventional AuGeNi alloyed ohmic contact. For a 0.5 μm-gate device, a maximum extrinsic transconductance of 1.2 S/mm was obtained at 4.2 K, even at a very low drain voltage of 0.2 V. These results show that this ohmic contact formation allows us to obtain the improved HEMT characteristics.

Original languageEnglish
Pages (from-to)458-462
Number of pages5
JournalPhysica E: Low-Dimensional Systems and Nanostructures
Issue number1-4
Publication statusPublished - 1998 Jul 15
Externally publishedYes


  • Direct ohmic contact
  • High electron mobility transistor
  • InAs

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics


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