Evaluation of p-GaN-gate All-GaN Cascode HEMT on SiC Substrate: DC Characteristics and Switching Performance

This article compares p-GaN-gate all-GaN cascode devices with standalone E-mode HEMTs on SiC substrates, with a focus on double pulse testing (DPT), a critical method for evaluating switching performance under realistic operating conditions. The all-GaN cascode, featuring a gate width of 85 mm, demonstrates a current rating of 15.6 A, an on-resistance of 7.7 mΩ-cm2, a breakdown voltage of 970 V, and turn-on/off times of 71/52 ns, respectively. Additionally, it exhibits switching energy losses of 17/8.2 μJ at VDS = 400 V and IDS = 1 A. Its dynamic RDS,on is measured at 0.7 μΩ at VDS = 300 V and IDS = 1 A. The experimental results indicate a significant improvement compared to the standalone E-mode HEMT. This highlights the advantages of the all-GaN cascode in reducing dynamic resistance and enhancing switching efficiency, making it an excellent choice for high-performance applications.