Low-noise GaN Schottky diodes on Si(111) by molecular beam epitaxy

We report on the achievement of mesa-isolated Schottky diodes fabricated from n-GaN epilayers grown by gas-source molecular beam epitaxy on Si(111) that exhibit extremely low noise and dark current. Silicon dioxide grown by plasma-enhanced chemical vapor deposition provided both surface passivation and electrical isolation, and the Schottky contact was a 10 nm Pd thin film. The dark current of an 86×86 μm2 diode was 2.10×10−8 A/cm2 at −2 V bias, and the zero-bias noise power density at 1 Hz is as low a 9×10−29 A2/Hz.