Improved Stability of GaN MIS-HEMT With 5-nm Plasma-Enhanced Atomic Layer Deposition SiN Gate Dielectric

In this work, characterizations are performed to investigate the stability of an mm-wave GaN metal-insulator-semiconductor HEMT. Bias temperature instability (BTI) experiment conducted at various voltages and temperatures show a highly stable threshold voltage ( ${V}_{\text {TH}}$ ) with both positive BTI (PBTI) and negative BTI (NBTI) attributing to the high quality of SiN gate dielectric. In addition, ${V}_{\text {TH}}$ shift ( ${\Delta } {V}_{\text {TH}}$ ) under reverse-bias step-stress is further monitored, achieving small ${\Delta } {V}_{\text {TH}} < {0.1}$ V and a recoverable behavior below ${V}_{\text {D}}$ , stress = 60 V. After 10 ⁴ s of stress at 175°C, under the OFF-state high drain-bias, ${\Delta } {V}_{\text {TH}}$ is 0.15 V, and a larger ${V}_{\text {TH}}$ shift (0.23 V) is observed under On-state drain-bias of 28 V due to the high electric-field. According to the time-dependent dielectric breakdown prediction, +3.0 V gate voltage stress at a failure rate of 0.01 % can be extrapolated for mm-wave MIS-HEMT. These findings guarantee a good stability for the device utilized in power amplifier applications.