Temperature dependent contact and channel sheet resistance extraction of GaN HEMT

In this paper, we carried out a detailed characterization and evaluation of temperature sensitive on-resistance R_ON (T) of Gallium Nitride (GaN) based High Electron Mobility Transistors (HEMT) through DC and low frequency S-parameters measurements. The measurements are carried out at different chuck temperatures (T_chuck) and the R_ON (T) is calculated for different values of gate-source bias (V_GS) of AlN/GaN/AlGaN HEMT on silicon carbide (SiC) substrate. Knowing R_ON (T) values for different geometries of the device, we present a practical and simplified method to evaluate the temperature dependent series contact resistance R_se (T) and channel sheet resistance R_sh (T) of the technology.