An image sensor device includes a substrate having an active array region and a peripheral circuit region, a plurality of light-sensing elements disposed within the active array region, a first dielectric layer on the substrate, and a second dielectric layer on the first dielectric layer. A recess region is provided in the second dielectric layer to reveal a top surface of the first dielectric layer within the active array region. An angle between a sidewall of the second dielectric layer that defines the perimeter of the recess region and the top surface of the first dielectric layer is less than 90 degrees.