1.17 GW/cm² AlN-Based GaN-Channel HEMTs on Mono-Crystalline AlN Substrate
Mihaela Wolf, Frank Brunner, C. Last, Houssam Halhoul, D. Rentner, E. Bahat Treidel, Joachim Würfl, Oliver Hilt
Abstract
AlN-based GaN-channel HEMTs with MOCVD-grown AlGaN/GaN/AlN epistack were realized on AlN substrates, achieving 400 mA/mm current density at V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GS</sub> = 1 V and 125 V/μm breakdown voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Br</sub> ) scaling. Unlike for similar AlN-on-SiC devices, the high V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Br</sub> scaling also applies above 1000 V. This is attributed to the significantly reduced AlN-buffer defect density. A record power density of 1.17 GW/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> is extracted from a device with 2.2 kV breakdown voltage. High-voltage switching transients at 0.6 A / 464 V off-state voltage show dispersions effects attributed to the AlN-buffer/ GaN-channel interface quality.