A method of increasing the interquadrant resistance of four-quadrant p-i-n photodiodes

Abstract The paper investigates the influence of the insulation resistance of the responsive elements and the guard ring of a silicon 4-quadrant photodiode on its dark currents. It was found that a decrease in the insulation resistance leads to an increase in the dark current of the guard ring and responsive elements. It was found that the insulation resistance deteriorates due to the formation of surface inversion layers at the interface Si-SiO 2 . A method of increasing the insulation resistance of the active elements of the photodiode by etching oxide in the gaps between the responsive elements is proposed, thereby removing the conductive inversion channels. In the absence of an increase in the insulation resistance after these modifications, it is proposed to etch the surface layer of silicon in the gaps between the responsive elements by chemical-dynamic polishing with a gold masking layer. The proposed methods make it possible to significantly reduce the dark currents of the photodiodes, increase the insulation resistance between the responsive elements, and increase the percentage of yield of suitable products.