Diamond FET using high-quality polycrystalline diamond with fT of 45 GHz and fmax of 120 GHz

K. Ueda, M. Kasu, Y. Yamauchi, T. Makimoto, M. Schwitters, D. J. Twitchen, G. A. Scarsbrook, S. E. Coe

Research output: Contribution to journalArticlepeer-review

191 Citations (Scopus)


Using high-quality polycrystalline chemical-vapor-deposited diamond films with large grains (∼ 100 μ), field effect transistors (FETs) with gate lengths of 0.1 μ were fabricated. From the RF characteristics, the maximum transition frequency fT and the maximum frequency of oscillation fmax were ∼ 45 and ∼ 120 GHz, respectively. The fT and fmax values are much higher than the highest values for single-crystalline diamond FETs. The dc characteristics of the FET showed a draincurrent density IDS of 550 mA/mm at gate-source voltage VGS of 3.5 V and a maximum transconductancegm of 143 mS/mm at drain voltage VDS of - 8 V. These results indicate that the high-quality polycrystalline diamond film, whose maximum size is 4 in at present, is a most promising substrate for diamond electronic devices.

Original languageEnglish
Pages (from-to)570-572
Number of pages3
JournalIEEE Electron Device Letters
Issue number7
Publication statusPublished - 2006 Jul
Externally publishedYes


  • Field effect transistor (FET)
  • Hydrogen terminated
  • Polycrystalline diamond
  • RF performance

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

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