DC and Pulsed Characterization of GaN-based Single- and Double- Heterostructure Devices

In this paper we report the DC and pulsed characterization of devices fabricated from 5 different GaN-based single-(SH) and double-heterostructure(DH) epitaxial designs(Fig. 1). DC tests enlighten higher saturation current and also sub-threshold leakage currents in SH devices as compared to DH. Moreover, the presence of kink effect, quite pronounced on uncapped wafers, suggests that the application of a GaN capping layer effectively reduces surface charge trapping phenomena. Pulsed measurements show charge release at higher voltages due to a field assisted detrapping.