AlGaN-based Schottky barrier deep ultraviolet photodetector grown on Si substrate

This letter reports the influence of material quality and device processing on the performance of AlGaN-based Schottky barrier deep ultraviolet photodetectors grown on Si substrates. The thermal annealing can significantly improve Schottky barrier height and wet chemical etching can effectively remove etching damage. Meanwhile, the decrease of threading dislocation density and the pit size, especially the later, can substantially suppress reverse leakage. As a result, the reverse leakage current density of the as-fabricated deep UV photodetector was reduced down to 3×10 −8 A/cm 2 . Furthermore, the responsivity of the deep UV photodetectors was greatly improved by reducing the point defect concentration.