Patent ID: 11670648

Abstract:
A flicker-mitigating pixel-array substrate includes a semiconductor substrate and a metal layer. The semiconductor substrate includes a small-photodiode region. A back surface of the semiconductor substrate forms a trench surrounding the small-photodiode region in a cross-sectional plane parallel to a first back-surface region of the back surface above the small-photodiode region. The metal layer covers the first back-surface region, at least partially fills the trench, and surrounds the small-photodiode region in the cross-sectional plane. A method for fabricating a flicker-mitigating pixel-array substrate includes forming, on a back surface of a semiconductor substrate, a trench that surrounds a small-photodiode region of the semiconductor substrate in a cross-sectional plane parallel to a first back-surface region of the back surface above the small-photodiode region. The method also includes forming a metal layer on the first back-surface region and in the trench.