High Breakdown Voltage GaN Power HEMT on Si Substrate

GaN high electronic mobility transistor (HEMT) was fabricated on silicon substrate. A breakdown voltage of 800V was obtained without using field plate technology. The fabrication processes were compatible with the conventional GaN HEMTs fabrication processes. The length between drain and gate (Lgd) has a greater impact on breakdown voltage of the device. A breakdown voltage of 800V with maximum current density of 536 mA/mm was obtained while Lgd was 15μm and the Wg was 100μm. The specific on-state resistance of this devices was 1.75 mΩ·cm2, which was 85 times lower than that of silicon MOSFET with same breakdown voltage. The results establish the foundation of low cost GaN HEMT power electronic devices.