Normally-off AlGaN/GaN HFET with p-type GaN Gate and AlGaN Buffer

Conference: CIPS 2010 - 6th International Conference on Integrated Power Electronics Systems
03/16/2010 - 03/18/2010 at Nuremberg, Germany

Proceedings: CIPS 2010

Pages: 4Language: englishTyp: PDF

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Hilt, Oliver; Knauer, Arne; Brunner, Frank; Bahat-Treidel, Eldad; Würfl, Joachim (Ferdinand-Braun-Institut, Leibniz-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Strasse 4, 12489 Berlin, Germany)

A 1.5 A normally-off GaN transistor for power applications in p-type GaN gate technology with a modified epitaxial concept is presented. A higher threshold voltage is achieved while keeping the on-state resistance low by using an AlGaN buffer instead of a GaN buffer. Additionally, the AlGaN buffer acts as a back-barrier and suppresses source-drain punch-through currents in the off-state. P-GaN gate GaN transistors with AlGaN buffer will therefore yield higher breakdown voltages as compared to standard GaN buffer versions which results in an excellent VBr-to-RON ratio. The proposed normally-off technology shows save operation under elevated ambient temperature up to 200 °C without thermal runaway. In contrast to standard normally-on AlGaN/GaN HEMTs, a reverse diode operation is possible for offstate conditions which may enable improved inverter circuits.