Semiconductor structure with metal connection layer

A semiconductor structure, comprising:

• a substrate, containing first doping ions and including a pixel region, the pixel region including a photosensitive region and a floating diffusion region adjacent to the photosensitive region;
• a deeply doped region, in the photosensitive region of the substrate and containing second doping ions with a type different from the first doping ions;
• a floating diffusion area, in the floating diffusion region of the substrate and containing third doping ions with a type different from the first doping ions;
• a gate structure on the substrate at a junction of the photosensitive region and the floating diffusion region;
• a sidewall spacer on the photosensitive region of the substrate, on sidewalls of the gate structure, and on a top of the gate structure in the photosensitive region;
• a first doped region located in the floating diffusion area on one side of the gate structure, the first doped region having fourth doping ions with a type different from the first doping ions;
• a metal connection layer on the first doped region;
• a silicide block on sidewalls of the gate structure in the pixel region, on top of the gate structure, on the first doped region and the metal connection layer;
• an etching stop layer conformally covering the silicide block;
• an interlayer dielectric layer on the substrate exposed by the gate structure, the interlayer dielectric layer covering the gate structure;
• and
• source/ drain contact plugs, in the interlayer dielectric layer and electrically connected to the metal connection layer, wherein the source/drain contact plugs sequentially through the interlayer dielectric layer, the etching stop layer, and the silicide block to contact with the metal connection layer.