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Diamond devices for RF applications

MetadataDetails
Publication Date2016-08-01
AuthorsMakoto Kasu, Toshiyuki Oishi
InstitutionsSaga University

Diamond possesses a combination of ecepctional physical properties such as high breakdown field and carrier mobility, and therefore is expected to be high-efficient high-power devices. We solved a carrier doping by using nitrogen dioxide (NO <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;2&lt;/sub> ). In addition, we greatly improved stability by using aluminum oxide (Al <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;2&lt;/sub> O <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;3&lt;/sub> ) layer. These two break-through technologies enable us to thermal-stability high-performance diamond field-effect transistors (FETs). The diamond FET showed high maximum I <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;DS&lt;/sub> of -1.35 A/mm, cut-off frequencies, f <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;T&lt;/sub> of 35 GHz and f <sub xmlns:mml=“http://www.w3.org/1998/Math/MathML” xmlns:xlink=“http://www.w3.org/1999/xlink”&gt;MAX&lt;/sub> of 70 GHz and RF output power density of 2 W/mm at 1 GHz. The prospects and challenges of diamond RF power transistors will be also discussed.