Effect of Source Field Plate Cracks on the Electrical Performance of AlGaN/GaN HEMT Devices

Abstract

In the current study, the effects of cracks in source field plates (SFPs) on the electrical performance of AlGaN/GaN high electron mobility transistors (HEMTs) are investigated systematically using numerical simulation. In detail, the influence of crack width and junction angle in SFPs on device performance is studied. The results indicate that the SFP structure increases the breakdown voltage of a device, but the occurrence of cracks causes premature breakdown, which is confirmed experimentally by the structural analysis of these devices after breakdown. With an increase in crack width, the electrical performance becomes worse. A beveled SFP architecture is proposed by increasing the angle at the SFP junction to reduce the probability of cracking and enhance the reliability of the device. However, with an increase in bevel angle, the modulation effect of the SFP on the channel electric field is gradually weakened. Therefore, it is necessary to balance the relationship between electrical performance and bevel angle according to the actual demands. This work provides potential support for SFP structural optimization design for AlGaN/GaN HEMTs.