AlInGaN-based Epi for High Power Double Heterostructure Field Effect Transistors On Semi-insulating 6H-SiC Substrates

"We will develop commercially viable quaternary AlInGaN-based epitaxial wafer technology on semi-insulating 6H-SiC for manufacturing of reliable high microwave power transistors and amplifiers for new generation of radars and wireless communication systems.We will use our proprietary growth technology and unique buffer layer design to deposit quaternary AlInGaN-based Double Heterostructure Field Effect Transistor (DHFET) structures with InGaN channels on semi-insulating 6H-SiC substrates supplied by II-VI,Inc. This will allow us to combine the advantages of DHFET design (current collapse-free performance) with superior transport properties of epilayers grown over 6H-SiC substrates. We will perform detailed material/substrate interaction studies in order tooptimize In-content in the InGaN channel and graded buffer design in order to achieve maximum RF output power combined with lowest RF power degradation. Increase in thermal conductivity of the substrate material is crucial for improved thermal managementand, thus, increased microwave output and enhanced reliability of high-power devices. To date, most work in GaN-based high microwave power transistor development has been done using semi-insulating 4H-SiC substrates, which has less thermal conductivitythan predicted value of 4.9 W/cm-K for 6H poly-type material. In Phase I, we will demonstrate DHFET epilayers with carrier sheet density time mobility in excess of 1.5 x 1016 V-1s-1 gro