Annealing of defect states in reactive ion etched GaN

The Al0.11Ga0.89N-based photodiodes fabricated under different annealing ambient after inductively coupled plasma reactive ion etching process were studied. The dark current and photocurrent with different illuminated wavelengths were characterized. Higher photocurrent for the diode annealing in H2 ambient can be observed and attributed to the defect-assisted photocurrent. This photocurrent shows a strong annealing ambient dependence and causes the shift of cutoff wavelength in the responsivity spectrum. The surface state was characterized by the capacitance analysis with Schottky contact.