An image sensor includes a semiconductor substrate, a photodiode formed in the semiconductor substrate, a first impurity region formed in the semiconductor substrate spaced from the photodiode, a second impurity region formed in the semiconductor substrate spaced from the first impurity region, a first gate formed over the semiconductor substrate between the photodiode and the first impurity region, a second gate formed over the semiconductor substrate between the first impurity region and the second impurity region, a spacer formed over the fourth impurity region and a first sidewall of the second gate, and an insulating film formed over the photodiode, the first gate, the first impurity region and a second sidewall and a portion of the uppermost surface of the second gate.