A semiconductor structure for a CMOS image sensor includes a semiconductor substrate having a first side and a second side. A photodiode is disposed in the semiconductor substrate proximate to the first side. The photodiode accumulates image charge photogenerated in the photodiode in response to incident light directed through the second side. A deep trench isolation structure enclosing the photodiode. The deep trench isolation structure extends from the second side toward the first side. The deep trench isolation structure includes a light absorption region disposed at a first end of the deep trench isolation structure toward the first side.