Provided are a semiconductor integrated circuit (IC) device and a method of fabricating the same. The semiconductor IC device may include first, second and third deep wells of a first conductivity type formed in a semiconductor substrate, and electrically isolated from one another; first and second wells of a second conductivity type and an active pixel sensor (APS) array formed between a top surface of the semiconductor substrate and the first, second and third deep wells, respectively; and first, second and third protective wells of the first conductivity type formed in the semiconductor substrate. The first and second wells of the second conductivity type and the APS array may be connected to different power supply voltages. The first, second and third protective wells of the first conductivity type may surround side surfaces of the first and second wells and the APS array, respectively.