Performance Comparison of GaN Power Transistors and Investigation on the Device Design Issues

摘要

One normally-on N-channel AlGaN/GaN device and two types of normally-off GaN devices have been studied. The normally-on device with Sapphire substrate shows good I_(dast) and breakdown characteristics, but the gate leakage current is quite large. The first normally-off GaN hybrid metal insulator semiconductor - high electron mobility transistor (MIS-HEMT) grown on Si substrate exhibits good performance with positive threshold voltage of 3 V and the breakdown voltage of over 1800V. However the second normally-off GaN MOSFET structure is rather difficult to exhibit good blocking characteristic compared to GaN MIS-HEMT device due to inadequate device design.