Deep level investigation by capacitance and conductance transient spectroscopy in AlGaN/GaN/SiC HEMTs

Deep centers in AlGaN/GaN high electron mobility transistors (HEMTs) on SiC substrate have been characterized by capacitance deep level transient spectroscopy (DLTS) and conductance deep level transient spectroscopy (CDLTS). These measurements reveal the presence of three kinds of electron defects E1, E2 and E3 with activation energies of 0.52, 0.29 and 0.09eV, respectively and a hole-like trap HL1 with activation energy 0.905eV. The conductance DLTS using a gate pulse, shows an additional trap HL2, located at the surface. The localization and the identification of these traps are presented. Finally, these experimental results demonstrate the complementarities of these two techniques.