Abstract: An image sensor includes a plurality of unit pixels for sensing a light beam to generate an image data. Each of the unit pixels includes, a photoelectric element for sensing a light beam incident thereto and generating photoelectric charges, a transistor including a gate dielectric formed adjacent to the photoelectric element and a gate electrode formed on top of the gate dielectric and a capacitor structure including an insulating film formed on a portion of the photoelectric element and a bottom electrode, wherein the insulating film and the gate dielectric are made of a same material and the bottom electrode and the gate electrode are made of a same material.

Abstract: A unit pixel in a CMOS image sensor, which enhances a capacitance of a photodiode to reduce noises and increase the maximum output signal of the image sensor, is provided. To achieve this, the CMOS image sensor includes a photodiode aligned with an edge of an insulating film for separating elements and formed by doping impurities to a semiconductor layer by an ion implantation; and a capacitor formed along with interface between the photodiode and the insulating film on plan and formed by layering a bottom electrode, a dielectric and an upper electrode contacted with the photodiode.