Static and Dynamic Characterization of Silicon Carbide and Gallium Nitride Power Semiconductors

Abstract

Wide-bandgap semiconductors have made and are continuing to make a major impact on the power electronics world. The most common commercially available wide-bandgap semiconductors for power electronics applications are SiC and GaN devices. This paper focuses on the newest devices emerging that are made with these wide-bandgap materials.

The static and dynamic characterization of six different SiC MOSFETs from different manufacturers are presented. The static characterization consists of the output characteristics, transfer characteristics and device capacitances. High temperature (up to 150 °C) static characterization provides an insight into the dependence of threshold voltage and on-state resistance on temperature. The dynamic characterizations of the devices are conducted by performing the double-pulse test. The switching characteristics are also tested at high temperature, with the presented results putting an emphasis on one of the devices. A comparison of the key characterization results summarizes the performance of the different devices.

The characterization of one of the SiC MOSFETs is then continued with a short-circuit failure mode operation test. The device is subjected to non-destructive and destructive pulses to see how the device behaves. The non-destructive tests include a look at the performance under different external gate resistances and drain-source voltages. It is found that as the external gate resistance is increased, the waveforms get noisier. Also, as the drain-source voltage is increased, the maximum short-circuit current level rises. The destructive tests find the amount of time that the device is able to withstand short-circuit operation. At room temperature the device is able to withstand 4.5 μs whereas at 100 °C, the device is able to withstand 4.2 μs. It is found that despite the different conditions that the device is tested at for destructive tests, the energy that they can withstand is similar.

This paper also presents the static and dynamic characterization of a 600 V, 2A, normallyoff, vertical gallium-nitride (GaN) transistor. A description of the fabrication process and the setup used to test the device are presented. The fabricated vertical GaN transistor has a threshold voltage of 3.3 V, a breakdown voltage of 600 V, an on-resistance of 880 mΩ, switching speeds up to 97 V/ns, and turn-on and turn-off switching losses of 8.12 µJ and 3.04 µJ, respectively, demonstrating the great potential of this device