1kV Vertical Breakdown Voltage AlGaN/GaN HEMTs on Si with AlN and AlGaN/AlN Superlattice Buffer Engineering

In this study, we investigated the device characteristics of AlGaN/GaN High-Electron-Mobility Transistors (HEMTs) fabricated on 6-inch silicon substrates using AlN and an Al<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.07</inf>GaN/AlN superlattice. Transmission electron microscopy revealed a sharp interface between the AlN and the Si substrate, effectively reducing leakage from the Si. Additionally, it showed a distinct interface between the AlGaN and AlN layers within the superlattice structure. The AlGaN/GaN HEMTs exhibited a vertical breakdown voltage of approximately 1000 V and maintained ultra-low leakage up to 700 V, with a three-terminal off breakdown voltage exceeding 1500 V. These results highlight the significant potential of both HLH-AlN and the AlGaN/AlN superlattice on silicon substrates for high-power switching applications.