Temperature effect on impact ionization characteristics in metamorphic high electron mobility transistors

Comprehensive studies of temperature-dependent gate-metal-related impact ionization in metamorphic high electron mobility transistors (MHEMTs) are demonstrated. It is known that, from experimental results, the electric field and temperature dependences of impact ionization mechanisms in MHEMT’s operation are dominated by the ionization threshold energy and hot electron population. The peak impact ionization-induced gate current could be substantially decreased by the presence of specific gate contact with a higher Schottky barrier height. Therefore, the suppressions of bell-shaped behavior and related impact ionization effect are observed by using the appropriate Schottky gate contacts.