Image Sensors Including Conductive Pixel Separation Structures

An image sensor, comprising:

• a substrate comprising a plurality of pixel regions, the substrate having a first surface and a second surface opposite the first surface, wherein the second surface is arranged to receive incident light;
• photoelectric conversion parts in the pixel regions of the substrate;
• gate electrodes and floating diffusion regions in the pixel regions of the substrate;
• a pixel separation structure including a first isolation region and a second isolation region in the substrate that separate the pixel regions from each other, wherein the first isolation region includes an insulating device isolation layer, and the second isolation region includes an impurity-doped region;
• and
• doped ground regions disposed between adjacent ones of the floating diffusion regions,
• wherein the first isolation region is in contact with the second surface and spaced apart from the first surface, and the second isolation region is disposed between the first isolation region and the first surface, and
• wherein in plan view, the floating diffusion regions and the doped ground regions are arranged in a straight line.