A photodiode includes a substrate having a first semiconductor type surface region on at least a portion thereof, and a second semiconductor type surface layer formed in a portion of the surface region. A multi-layer anti-reflective coating (ARC) is on the second semiconductor type surface layer, wherein the multi-layer ARC comprises at least two different dielectric layers. A layer resistant to oxide etch is above a peripheral portion the multi-layer ARC. Further layers are above the layer resistant to oxide etch, and thereby above the peripheral portion the multi-layer ARC. A window extends down to the multi-layer ARC. A photodiode region is formed by a pn-junction of the first semiconductor type surface region and the second semiconductor type surface layer.