Abstract: A reflective mirror layer is formed over a silicon substrate and is then selectively etched to define a crossover pad region, a pixel array region, and a bonding pad region on the silicon substrate. A dielectric layer is deposited over the crossover pad region, the pixel array region and the bonding pad region, and a plurality of crossover pad vias are formed within the crossover pad region thereafter. By filling the crossover pad vias with conductive material, a plurality of plugs is formed in the plurality of the vias. Then, a top pad, electrically coupled to the bottom pad via the plugs, is formed over the crossover pad region. A spacer pattern on the dielectric layer within the pixel array region is defined thereafter. Finally, the dielectric layer is etched to form a plurality of spacers within the pixel array region.