Patent ID: 10276625

Abstract:
A CMOS image sensor may include a semiconductor substrate having a first conductivity type, and a plurality of laterally adjacent infrared (IR) photodiode structures on the substrate. Each IR photodiode structure may include a superlattice on the semiconductor substrate including a plurality of stacked groups of layers, with each group of layers including a plurality of stacked base semiconductor monolayers defining a base semiconductor portion, and at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions. Further, the superlattice may have the first conductivity type. The CMOS image sensor may further include a semiconductor layer on the superlattice, a retrograde well extending downward into the semiconductor layer from a surface thereof and having a second conductivity type, a first well around a periphery of the retrograde well having the first conductivity type, and a second well within the retrograde well having the first conductivity type.