Stable and High Performance AlGaN Self-Aligned-Gate Field Emitter Arrays

AlGaN alloys are promising for field emission devices due to their low electron affinities. However, there have been limited demonstrations of vacuum transistors so far. This letter combines a new self-aligned-gate (SAG) process and digital-etching tip sharpening demonstrate three-terminal SAG emitter arrays (FEAs). These show turn-on voltage 19.5 V an anode current density (J A ) 100 mA/cm 2 at overdrive 20 V, which comparable with best Si devices. The SAGFEAs can operate in DC mode fixed gate-emitter ( $\text{V}_{\textit {GE}}$ J 3–5 least 5 hours without significant degradation. gate leakage does not increase after the long operation, suggesting high-performance stable transistors.