An image sensor and method of fabrication wherein the sensor includes
Copper (Cu) metallization levels allowing for incorporation of a thinner
interlevel dielectric stack to result in a pixel array exhibiting
increased light sensitivity. The image sensor includes structures having
a minimum thickness of barrier layer metal that traverses the optical
path of each pixel in the sensor array or, that have portions of barrier
layer metal selectively removed from the optical paths of each pixel,
thereby minimizing reflectance. That is, by implementing various block or
single mask methodologies, portions of the barrier layer metal are
completely removed at locations of the optical path for each pixel in the
array. In a further embodiment, the barrier metal layer may be formed
atop the Cu metallization by a self-aligned deposition.