Monday, 10 October 2022: 09:00
Room 213 (The Hilton Atlanta)
Top-side diamond heat sinks facilitate heat removal from hot-spots near the gate electrode of power MOSFETs. For GaN-based devices however, diamond growth processes will etch GaN layers, damaging device structures and lowering thermal boundary conductance (TBC). In this study, we combat GaN-etching using two methods: altering the Al-concentration of AlGaN films and by implanting Nitrogen on the surface of AlGaN.
First, for the Al concentrations of 0, 10, 25, 50, 75% (compared to Ga), we measure the TBC of AlGaN/Diamond interfaces using time-domain thermoreflectance. The integrity of these AlGaN/Diamond interfaces is inspected via tunneling-electron microscopy.
Second, we use hyperthermal ion-implantation to implant Nitrogen on the surface of an AlGaN film. Implanting concentration is varied across the sample from 0% to 20% areal defect density, followed by diamond growth. Scanning measurements across the sample, a high-throughput map of TBC versus implant concentration is obtained. Local maxima in TBC identify ideal concentrations of Nitrogen.