A backside illuminated sensor includes a semiconductor substrate having a front surface and a back surface and a plurality of pixels formed on the front surface of the semiconductor substrate. A dielectric layer is disposed above the front surface of the semiconductor substrate. The sensor further includes a plurality of array regions arranged according to the plurality of pixels. At least two of the array regions have a different radiation response characteristic from each other, such as the first array region having a greater junction depth than the second array region, or the first array region having a greater dopant concentration than the second array region.