Fabrication and characterization at high temperature of AlGaN/GaN enhancement-mode HEMTs

Enhancement-mode (E-mode) high electron mobility transistors (HEMTs) based on a standard AlGaN/GaN heterostructure have been fabricated using two different methods: ¹⁹F implantation and fluorine-based plasma treatment. The need of a thermal annealing after both treatments has been proven in order to restore the I_D and g_m levels. DC characterization at high temperature has demonstrated that I_D and g_m decrease reversibly due to the reduction of the electron mobility and the drift velocity. Pulsed measurements (state period and variable pulse width) have been performed to study the self-heating effects.