Method of protecting a bond pad structure, of a color image sensor cell, during a color filter fabrication process

A process for forming a color image sensor cell, in which a bonding pad structure is protected from exposure to alkaline developer solution, used for definition of color filter elements, and also used to open a contact hole to the bonding pad structure, has been developed. The process features the use of a passivation layer, comprised of an overlying silicon nitride layer, and an underlying silicon oxide layer, located on the top surface of the bonding pad structure. The passivation layer protects the underlying bond pad structure from alkaline developer solutions used to define overlying color filter elements, of the color image sensor cell. After definition of the color filter elements the contact hole opening to the bond pad is finalized using a dry etching procedure, applied to the passivation layer. By use of this invention the bond pad structure is protected by the passivation layer during the color filter process, preventing stain and discolouring of the bond pad structure, by the alkaline developer solution used for definition of the color filter elements, thus resulting in improvements of the mechanical properties, as well as the bondabilty properties, of bond pad structure.