US Patent 10367023 Semiconductor image sensor

In some embodiments, the present disclosure relates to an image sensor integrated chip. The integrated chip has an image sensing element arranged within a pixel region of a substrate. A first dielectric is disposed in trenches within a first side of the substrate. The trenches are defined by first sidewalls disposed on opposing sides of the pixel region. An internal reflection enhancement structure is arranged along the first side of the substrate and is configured to reflect radiation exiting from the substrate back into the substrate.