Abstract: An image sensor comprises a substrate of a first conductivity type. First and second pixels are arrayed over the substrate. A potential barrier is formed in a region of the substrate corresponding to the first pixel but not in a region of the substrate corresponding to the second pixel. The second pixel is responsive to a color having a wavelength longer than the color to which the first pixel is responsive. The potential barrier is doped with dopants by a high energy ion implantation dopants or by an ion implantation or diffusion during epitaxial growth of the P-type epitaxial layer.

Abstract: An image sensor includes a color filter, an over-coating layer formed on the color filter, and a medium layer formed on the over-coating layer, wherein the medium layer is configured with at least two medium layers of which refractive indices are different from each other.