High Output Power Density of 2DHG Diamond MOSFETs with Thick ALD-Al2O3

Ken Kudara, Shoichiro Imanishi, Atsushi Hiraiwa, Yuji Komatsuzaki, Yutaro Yamaguchi, Yoshifumi Kawamura, Shintaro Shinjo, Hiroshi Kawarada*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)


This article reports on the high operation voltage large-signal performance of two-dimensional hole gas diamond metal-oxide semiconductor field-effect transistors (MOSFETs) with thick atomic-layer-deposition (ALD)-Al2O3 formed on high purity polycrystalline diamond with a (110) preferential orientation. MOSFETs with a 1-μ m gate-length having a gate oxide layer of 200-nm-thick Al2O3, formed by ALD and asymmetric structures, to withstand high-voltage operations. The large-signal performances were evaluated at a quiescent drain voltage of greater than-60 V for the first time in diamond field-effect transistor (FET). As a result, an output power density of 2.5 W/mm under class-A operation at 1 GHz, which is higher than that of diamond FETs fabricated by a self-aligned gate process, was obtained. Moreover, an output power density of 1.5 W/mm was exhibited by the MOSFET when biased at a quiescent drain voltage of-40 V under class-AB operation at 3.6 GHz using an active load-pull system. This is the highest recorded value for diamond FETs at a frequency greater than 2 GHz, owing to the high-voltage operation. These results indicate that diamond p-FETs under high-voltage operations are the most suitable for high-power amplifiers with complementary circuits.

Original languageEnglish
Article number9465224
Pages (from-to)3942-3949
Number of pages8
JournalIEEE Transactions on Electron Devices
Issue number8
Publication statusPublished - 2021 Aug


  • Diamond field-effect transistor (FET)
  • metal-oxide semiconductor field-effect transistor (MOSFET)
  • output power density
  • radio frequency

ASJC Scopus subject areas

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


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