GaN technology for power RF applications: Present reliability roadblocks and future trends

The current collapse and normally-on devices are the main roadblocks to the wider employment of the GaN technology. To explain the current collapse effect, surface and bulk trapping/de-trapping phenomena are modeled using 2D drift-diffusion and hydro-dynamic transport models by transient simulations within Silvaco TCAD. The current collapse next to 75% and 5% was observed due to surface and bulk trapping, respectively. The combined surface and bulk trapping is studied using a gate-lag technique showing a good qualitative agreement with experimental observations.