Temperature dependence of Al/Ti-based Ohmic contact to GaN devices: HEMT and MOSFET
In this paper two types of Al/Ti-based Ohmic contacts to Gallium Nitride (GaN) based devices are presented; ImplantedN+GaN (like the ones found in the Source/Drain of GaN Metal Oxide Semiconductor Field Effect TransistorsMOSFET) and heterojunction (HJ) AlGaN/GaN contacts (Source/Drain of High Electron Mobility TransistorsHEMT). Sheet resistance (Rsh) and contact resistance (Rc) have been investigated in the temperature (T) range of 25250C. It was found that the Rsh (850/700??) (25/250C) and Rc (2.2/0.7?mm) decrease with T for ImplantedN+GaN contact and Rsh (400/850??) and Rc (0.2/0.4?mm) (weakly for Rc) increase with T for HJAlGaN/GaN contact. Numerical computation based models are used to determine the theoretical Rsh and Rc behavior with T and to fit the experimental values.
temperature ohmic contact gan hemt mosfet modeling tlm