Photogate sensor with improved responsivity

DETAILED DESCRIPTION According to one aspect of the present invention, there is provided a depleted-gate photosensor, comprising a substrate comprising crystalline silicon, the substrate defining a main surface including an exposure area exposable to light.
An oxide layer is disposed adjacent the main surface of the substrate, the oxide layer defining a gap of non-oxide material in the main surface of the substrate, and including oxide immediately adjacent the gap within the exposure area.
A polysilicon layer is disposed on the main surface, the polysilicon layer substantially covering the gap and extending over a portion of the exposure area and over a portion of the oxide layer immediately outside the gap.