Embodiments relate to and image sensor. In embodiments, the image sensor may include a semiconductor substrate, a photodiode region, a gate electrode, a dummy gate, and an interlayer dielectric layer. The semiconductor substrate includes a field oxide layer. The photodiode region may be formed on the semiconductor substrate. The gate electrode may be formed on the semiconductor substrate. The dummy gate may be formed on the field oxide layer. The interlayer dielectric layer may be formed on one side of the dummy gate and includes an opening exposing the photodiode region.