Effects of buffer compensation strategies on the electrical performance and RF reliability of AlGaN/GaN HEMTs

The effects of buffer compensation strategies on the electrical performance and RF reliability of AlGaN/GaN HEMTs have been studied by means of static and dynamic I-V measurements, drain-current transient spectroscopy, XRD, and RF stress tests. Devices equipped with C-doped and Fe-doped GaN buffer feature improved subthreshold behaviour (lower source-to-drain leakage current, and lower DIBL) and improved RF reliability. As a drawback, devices equipped with Fe- and C-doping experience higher dynamic current dispersion, ascribed to higher concentration of the deep levels E2 (0.56 eV/10- 15 cm2) and E4 (0.84 eV/10- 14 cm2).