Patent ID: 7956432

Claim:
A photodiode, comprising: a substrate having a first semiconductor type surface region on at least a portion thereof; a second semiconductor type surface layer formed in a portion of said surface region, wherein a photodiode region is formed by a pn-junction of said first semiconductor type surface region and said second semiconductor type surface layer; a multi-layer anti-reflective coating (ARC) on said second semiconductor surface layer, wherein said multi-layer ARC comprises an oxide layer on said second semiconductor type surface layer and a second dielectric layer different from said oxide layer on said oxide layer; an etch stop layer stack on a first portion of said multi-layer ARC, said etch stop layer stack including a layer resistant to oxide etch on an oxide or other layer; at least one dielectric layer on said etch stop layer stack; and a window over at least a portion of said photodiode region, said window extending through said etch stop layer stack down to said multi-layer ARC such that an opening through said etch stop layer stack is created by said window with said etch stop layer stack surrounding said opening.