The interplay of thermal, time and Poole-Frenkel emission on the trap-based physical modeling of GaN HEMT drain characteristics

To model drain IV characteristics, the temperature dependence is important for GaN HEMT. We show that the time dependence should also be included in the modeling approach. In this paper, we use the trap information obtained from current transient spectroscopy (CTS) to create a 3D plot of Ids-Vds-time(I-V-t). This gives a more realistic description for time-domain pulsed IV behavior. The controversial question of whether the pulsed IV/RF is a trapping effect or a thermal effect is analyzed. The Poole-Frenkel emission-based time-dependent trapping model is proposed to describe the GaN HEMT memory effects (kink effect and knee walkout). To our knowledge, this is the first model offered to describe the “soft” (or degraded) knee region of the GaN HEMT IV curves.