Choice of Substrate for GaN based HEMT devices using Thermal Modelling

P.Kandpal[1], Dr. Meena Mishra [2]
[1]Department of Electronic Sceince KUK, Kurukshetra, Haryana, India
[2]Solid State Physics laboratory (DRDO), Delhi, India
Published in 2013

Gallium Nitride (GaN) is a very interesting and highly promising material system for both optical and microwave high-power electronic applications. It plays a crucial role today in the most promising technology for high power, high-frequency circuits: AlGaN/GaN HEMTs.

GaN HEMTs differing by substrate material and heat removal strategy are simulated and compared in order to choose a proper substrate for proper thermal management. The temperature non-uniformity along the finger width is the most critical for the case of sapphire, where the substrate’s low thermal conductivity tends to confine the heat flow in the thin top GaN layer. So, SiC is considered to be a best substrate among all these three substrates.