An image sensor comprising: a substrate including, a first region, a second region, a first surface and a second surface opposite each other, the substrate including a plurality of unit pixel regions in the substrate, each of the plurality of unit pixel regions including a photoelectric conversion layer; a pixel defining pattern extending through the substrate in a first direction, the pixel defining pattern defining each of the plurality of unit pixel regions, the pixel defining pattern includes a first conductive layer and a second conductive layer spaced apart from the first conductive layer; a micro lens on the second surface of the substrate in the first region of the substrate, and the micro lens corresponding to the plurality of unit pixel regions; wherein the pixel defining pattern includes a first defining pattern and a second defining pattern aligned with each other in the first direction and including the first and second conductive layers respectively; a first pad pattern on the second surface of the substrate in the second region of the substrate, the first pad pattern being electrically connected to the first defining pattern; and a second pad pattern on the second surface of the substrate in the second region of the substrate, the second pad pattern being electrically connected to the second defining pattern, wherein the second defining pattern is in contact with the substrate, wherein the first defining pattern includes a liner film and a first conductive layer on the liner film, the liner film is disposed along and on a sidewall of the first trench and a bottom surface of the first trench. a substrate including, a first region, a second region, a first surface and a second surface opposite each other, the substrate including a plurality of unit pixel regions in the substrate, each of the plurality of unit pixel regions including a photoelectric conversion layer; a pixel defining pattern extending through the substrate in a first direction, the pixel defining pattern defining each of the plurality of unit pixel regions, the pixel defining pattern includes a first conductive layer and a second conductive layer spaced apart from the first conductive layer; a micro lens on the second surface of the substrate in the first region of the substrate, and the micro lens corresponding to the plurality of unit pixel regions; wherein the pixel defining pattern includes a first defining pattern and a second defining pattern aligned with each other in the first direction and including the first and second conductive layers respectively; a first pad pattern on the second surface of the substrate in the second region of the substrate, the first pad pattern being electrically connected to the first defining pattern; and a second pad pattern on the second surface of the substrate in the second region of the substrate, the second pad pattern being electrically connected to the second defining pattern, wherein the second defining pattern is in contact with the substrate, wherein the first defining pattern includes a liner film and a first conductive layer on the liner film, the liner film is disposed along and on a sidewall of the first trench and a bottom surface of the first trench.