Abstract

This paper uses a 2D finite volume numerical model to predict the steady state and transient temperature distributions in a High-Electron-Mobility Transistor (HEMT). The numerical predictions are confirmed through comparison with analytical solutions of the one and two dimensional steady and transient heat equations. We analyze the thermal performance of several HEMT geometries with varying substrate materials. Devices with wider gates lying directly on highly conductive substrates (e.g., diamond) have significantly less thermal resistance, by as much as 90 percent. Finally, we investigate the temperature response to a frequency modulated heating event. This result indirectly applies to thermal measurements using 3ω electrical thermometry.