Normally-off matrix layout p-GaN gate AlGaN/GaN power HEMT with a through-substrate via process

Normally-off p-GaN gate AlGaN/GaN high electron mobility transistor (HEMT) on Si substrate with matrix heat redistribution layer (RDL) and through substrate via (TSV) technologies was investigated. Compared to traditional power cell design, the modified matrix heat RDL provides a circular arc layout together with an extra drain pad to reduce rectangular layout induced leakage current and the device total current density was also enhanced. In addition, TSV process beneath the GaN power HEMT active region spreads the heat efficiently and the lattice mismatch induced traps in transition/buffer layer were also removed. Based on the measured results analysis of dynamic R_ON to DC R_ON (R_DC), the removal of lossy substrate in TSV is also beneficial for improving device switching behavior. Therefore, a high switching speed normally-off GaN power HEMTs together with a superior thermal management was proposed in this study.