Improved Test Circuit for Characterization of the Dynamic On-Resistance of GaN-HEMTs over a Wide Operating Range

GaN-HEMTs show excellent switching and conduction characteristics and are an excellent candidate to replace Si-based power semiconductors with voltage ratings of up to $650 \, \mathrm{V}$. However, trapping phenomena, such as the dynamic on-resistance $R_\mathrm{ds,on}$, have not yet been fully eliminated. As these can significantly influence the conduction losses and reliability of GaN-HEMTs, suitable characterization methods are required. This paper presents an improved test circuit to characterize the dynamic on-resistance $dR_\mathrm{ds,on}$ over a wide operating range. This includes positive and negative drain currents \gls{sym:id}, adjustable gate-voltages $V_\mathrm{gs}$ and temperatures $T_\mathrm{c}$. In order to stimulate trapping phenomena, the bias voltage on the DUT (Device Under Test) in the off-state $V_\mathrm{ds}$ is adjustable in magnitude and duration (soak time). In addition, the drain current $I_\mathrm{d}$ of the DUT only flows for the duration of the measuring interval, which leads to less self-heating. For an improved measurement of the drain-source voltage $V_\mathrm{ds}$ in the on-state, an improved clamp-circuit was developed. ... mehrWith small modifications to the test circuit, switching characteristics can also be measured.