Photodiode for multiple wavelength operation

Abstract

A method of a fabricating a multiple wavelength adapted photodiode and resulting photodiode includes the steps of providing a substrate having a first semiconductor type surface region on at least a portion thereof, implanting and forming a second semiconductor type shallow surface layer into the surface region, and forming a multi-layer anti-reflective coating (ARC) on the shallow surface layer. The forming step includes depositing or forming a thin oxide layer on the shallow surface layer and depositing a second dielectric layer different from the thin oxide layer on the thin oxide layer. An etch stop is formed on the second dielectric, wherein the etch stop includes at least one layer resistant to oxide etch. At least one oxide including layer (e.g. ILD) is then deposited on the etch stop. The oxide including layer and etch stop are then removed to expose at least a portion of the ARC to the ambient.