n-ZnO/p-Si photodiodes fabricated using ion-beam induced isolation technique

We report on the fabrication of a new Si-based photodiode that has both insulating ZnO and n-ZnO overlayers. Thin n-ZnO layer was deposited on p-Si at 480 deg. C by RF magnetron sputtering and an insulating ZnO film was subsequently deposited at room temperature using the same deposition method. Silicon ions at 100 keV with doses of 5 x 1013, 5 x 1014 and 5 x 1015 cm-2 were implanted into n-ZnO area, that was in the outside of an active device window, for inter-device isolation. The dark leakage current of the implanted photodiode clearly decreases with the dose. As measured under red laser illumination of 670 nm, photoresponsivity of 0.28 A/W and quantum efficiency of about 50% were obtained from our new n-ZnO/p-Si photodiode