Image sensor with V-shape deflector structures for sensor edge performance improvement

VisEra demonstrated a three-layer V-shape deflector (VSD) structure on a CMOS image sensor (CIS). The three-layer VSD structure, which is on top of the microlens layer, is composed of an anti-reflection layer, a high refractive index layer, and a low refractive index layer from top to bottom. The angled facets of the VSD structure deflect the light to smaller angles and enter pixels efficiently at CIS die edge. The VSD structure improves the quantum efficiency (QE) by 15.3% at chief ray angle (CRA) 30˚ and has a efficiency improvement gain of 1.27 times at CRA 28˚. Obviously, the VSD has the function of improving edge performance. The only issue needs to be solved is the uneven-black-lines on CIS, which we believe one way to eliminate the uneven-black-lines is to further shrink the VSD structure to a size around pixel pitch.