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Over 1 A Operation of Vertical-Type Diamond MOSFETs

MetadataDetails
Publication Date2024-08-07
JournalIEEE Electron Device Letters
AuthorsNobutaka Oi, Satoshi Okubo, Ikuto Tsuyuzaki, Atsushi Hiraiwa, Hiroshi Kawarada
InstitutionsWaseda University
Citations4

Diamond is a promising material for p-channel power field-effect transistors (FETs) due to its remarkable physical properties. However, no diamond FETs with current characteristics exceeding 1 A have so far been reported. P-channel FETs capable of high-current operation are essential in order to realize complementary inverters with n-channel wide bandgap devices such as SiC or GaN. In this work, we designed and fabricated vertical-type diamond metal-oxide-semiconductor FETs (MOSFETs) with a trench structure, and a gate width (W <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;G&lt;/sub> ) of 0.1 to 10 mm. For devices with W <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;G&lt;/sub> = 10 mm and a source-drain voltage ( <italic xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;V&lt;/i> <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;DS&lt;/sub> ) of -20 V, the drain current reached 0.7 A. We obtained a maximum drain current of over 1.5 A with <italic xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;V&lt;/i> <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;DS&lt;/sub> = -20 V by connecting two devices in parallel within a chip. The drain current density and specific on-resistance at a <italic xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;V&lt;/i> <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;DS&lt;/sub> of -10 V were 85 mA/mm and 118 Ω·mm, respectively (W <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;G&lt;/sub> = 2 mm). The leakage current in the off state is at the lower limit of the measurement (~10 <sup xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;-11&lt;/sup> A) and the on/off ratio is over nine orders of magnitude.