Avalanche and Tunneling Breakdown Mechanisms in HEMT´s Power Structures

The present paper reports a study on the breakdown phenomenon in AlGaAs/GaAs power HEMT´S. It uses, on one hand, experimental results carried out on various test devices and, on the other hand, modeling taking into account either ionization or tunneling effects. Such an approach gives a new understanding on the respective roles of these two effects in the breakdown occurrence and allows to define design rules.