To break through the material limits of Silicon and to realize the drastic performance improvement needed to meet the severe requirements in the future, wide bandgap semiconductors such as SiC and GaN have attracted much attention. AlGaN/GaN HEMTs are generally promising candidates for switching power transistors due to their high breakdown strength and the high current density in the transistor channel giving a low on-state resistance. Further, there exists a high requirement for simulation tools to accurately predict device performance prior to fabrication because of the high inherent cost of the cut-and-try method.

Since lighting is estimated to account for 20% of the world’s electricity consumption, the search for reliable and efficient lighting technologies to replace incandescent and fluorescent modules is intense.

GaN heterojunction field effect transistors (HFETs) have been under extensive investigation because of their projected superb performances as high-power RF devices. The inherently high breakdown field arising from the wide bandgap guarantees not only the high power input/output characteristics but also extreme device shrinkage which is a huge advantage for increasing the highest operation frequency. Two-dimensional electron gas (2-DEG) with the charge density ten times higher than that of GaAs-based HFET and the mobility well exceeding Si enables a very low on-state resistance indispensable to RF devices. Although the superiority of the device characteristics has been demonstrated, the self heating effect has hindered the production of high power and high speed GaN-based switching devices. This effect can be significantly reduced by the cost effective heat-sink approach (Flip chip or through wafer via)[1,2].