Temperature dependence of impact ionization in AlGaN–GaN heterostructure field effect transistors

We report on the studies of the impact ionization in AlGaN–GaN heterostructure field effect transistors in the temperature range 17–43 °C. The results show that the breakdown voltage and the characteristic electrical field Ei of the impact ionization have a positive temperature coefficient. The value of Ei at room temperature is estimated to be approximately 2.6 MV/cm, which agrees with recent theoretical prediction [J. Kolnik et al., J. Appl. Phys. 82, 726 (1997)].