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

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

237 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


Dive into the research topics of 'Diamond FET using high-quality polycrystalline diamond with fT of 45 GHz and fmax of 120 GHz'. Together they form a unique fingerprint.

Cite this