Backside illumination CMOS image sensors having convex light-receiving faces and methods of manufacturing the same. A backside illumination CMOS image sensor includes a metal layer, an insulating layer and a photodiode. The insulating layer is on the metal layer. The photodiode is on the insulating layer, and a top face of the photodiode, which receives light, is curved. A method of manufacturing a backside illumination CMOS image sensor including a photodiode having a convex surface includes forming an island smaller than the photodiode on a portion of a light-receiving face of the photodiode, and annealing the island to form the photodiode having the convex light-receiving face.