IMAGE SENSOR

An image sensor includes a semiconductor substrate having a first surface and a second surface opposite to the first surface, a first pixel isolation structure disposed in a first trench which vertically extends from the first surface of the semiconductor substrate and defines a plurality of pixel regions, and a second pixel isolation structure disposed in a second trench vertically extending from the second surface of the semiconductor substrate. The second pixel isolation structure overlaps the first pixel isolation structure. The first pixel isolation structure includes a liner semiconductor pattern defining a gap region in the first trench, the liner semiconductor pattern including sidewall portions and a bottom portion connecting the sidewall portions, a liner insulating pattern disposed between the liner semiconductor pattern and the semiconductor substrate, and a capping insulating pattern disposed in the gap region of the liner semiconductor pattern.