A photodiode structure augmented with active area photosensitive regions is used for detecting impinging radiation. The photodiode includes a semiconductor base layer doped with impurities of a first carrier type, a field oxide layer disposed upon the base layer with an opening formed therethrough, a plurality of auxiliary oxide layers wherein each is separately disposed upon the base layer, and a semiconductor diffusion layer doped with impurities of a second carrier type arranged upon the base layer and in contact with the oxide layers. When the photodiode is electrically energized, a plurality of integral photosensitive regions is created within the depletion region to facilitate the detection of impinging radiation at an increased quantum efficiency.