A novel photodiode array structure with double-layer SiO2 isolation

Abstract

Abstract A novel photodiode array structure is proposed and implemented in the paper. Based on the silicon-on-insulator substrate, the structure adopts double SiO2 layers for isolation among PN junctions. Compared with incumbent photodiode arrays with a single isolation layer, the novel design shows less leakage current, less noise, high optical response sensitivity, and better compatible integration with other devices. The dark current of this structure is less than nanoamperes (10−9 A), with the benefits of 1000 times’ less leakage current than that of other structures, and a higher sensitivity with a response speed less than 200 ns. The device is fabricated and characterized. The doping concentration and structural profile are characterized. The fabricated device is packaged with a photo light-emitting diode and the MOS device to act as the MOS relay driver. The wavelength used in the photodiode is between 500 nm–560 nm, with peak wavelength 520 nm, which can be used to drive MOS device.