High-Voltage E-Mode p-GaN Gate HEMT on Sapphire With Gate Termination Extension

An enhancement-mode (E-mode) p-type gallium nitride (p-GaN) gate high electron mobility transistor with a gate termination extension (GTE-HEMT) has been developed on a sapphire substrate, intended for power switching applications of kilovoltage (kV) level. The GTE-HEMT device exhibits a low ON-resistance ( R $_{\biosc{on}}$ ) of 19.3 $\Omega$ $\cdot$ mm, corresponding to a specific R $_{\biosc{on}}$ ( R $_{\biosc{on},\text{SP}}$ ) of 7.33 m $\Omega$ $\cdot$ cm $^{\text{2}}$ . Notably, the GTE-HEMT has achieved a breakthrough by increasing the breakdown voltage (BV) to 2573 V, surpassing the conventional p-GaN gate HEMT (Conv-HEMT) with its BV of 1679 V. The enhanced BV is ascribed to the gate termination extension (GTE) that reduces the gate-edge electric field peak, similar to a junction termination extension (JTE) in traditional Si power devices. In addition, the dynamic R $_{\biosc{on}}$ of the GTE-HEMT has been improved, with a normalized dynamic R $_{\biosc{on}}$ (dynamic R $_{\biosc{on}}$ /static R $_{\biosc{on}}$ ) of 1.4 and 2.6 for 650-and 1200-V OFF-state stress, respectively. The GTE-HEMT has been benchmarked to the state-of-the-art GaN power transistors, demonstrating its potential for high-voltage applications.