AlGaN/GaN power HFET on silicon substrate with source-via grounding (SVG) structure

We have developed a high-power AlGaN/GaN HFET fabricated on 4-in conductive Si substrate with a source-via grounding (SVG) structure. The SVG structure enables efficient chip layout and high packing density by the vertical configuration. By establishing a high-quality epitaxial technology on a Si substrate and by significantly reducing the parasitic resistance, a very low specific on-state resistance of 1.9 mΩ·cm² is achieved. The breakdown voltage is as high as 350 V, which is attributed to the Si substrate acting as a backside field plate. Because of reduction of the parasitic inductance, very high level of current (2.0 kA/cm²) transients, i.e., a turn-on time of 98 ps and a turn-off time of 96 ps, are successfully measured for the first time.