Low capacitance contact structure for a solid state image sensor

摘要

This invention concerns a novel structure to create a low capacitance floating diffusion without changing or adding steps to the image sensor fabrication process. It consists of incorporation of a novel structure at the contact area between the floating diffusion and the gate electrode that reduces the junction capacitance of the floating diffusion and improves the sensitivity of the device (the structure features overlapping contact, gate, metalization and n-type regions which provide the electrical contact between the floating diffusion and the gate). Additionally, the structure has a low resistance diffusion region that is self aligned with a gate electrode.