An All-GaN cascode device with integrated plane-parallel capacitor with high dynamic breakdown voltage and high switching performance

All-GaN Cascode devices have been shown to have higher switching speeds than standalone E-mode devices. However, during the switching process of the device, the breakdown voltage drops significantly, this will greatly reduce the reliability of the device, especially in the presence of voltage overshoot. In this paper, an All-GaN Cascode structure with integrated plane-parallel capacitor structure is proposed, and the breakdown voltage in the switching process is referred to as the dynamic breakdown voltage. The test results show that the dynamic breakdown voltage is increased from 497 V to 639 V compared with the conventional structure. In addition, a dual-pulse test circuit is set up to test the switching performance of All-GaN Cascode devices under different conditions, it is proved that the series structure of All-GaN Cascode device can reduce the deterioration of switching performance caused by the increase of capacitance. The above results indicate that All-GaN Cascode devices may have great application potential in high speed and high voltage switching circuits.