Abstract: An image sensor includes a semiconductor substrate including a first surface and a second surface and having a photoelectric conversion region disposed therein. A floating diffusion region is disposed within the semiconductor substrate. The floating diffusion region is adjacent to the first surface. A buried gate structure is disposed within a buried gate trench extending from the first surface of the semiconductor substrate towards an interior of the semiconductor substrate, the buried gate structure including a first buried gate electrode inside a first buried gate trench adjacent to a first side part of the floating diffusion region, and a second buried gate electrode inside a second buried gate trench spaced apart from the first buried gate trench and adjacent to a second side part of the floating diffusion region, the second side part being opposite to the first side part.