A method of manufacturing a backside illuminated image sensor, including forming a first isolation layer in a first semiconductor layer, such that the first isolation layer defines pixels of a pixel array in the first semiconductor layer, forming a second semiconductor layer on a first surface of the first semiconductor layer, forming a second isolation layer in the second semiconductor layer, such that the second isolation layer defines active device regions in the second semiconductor layer, forming photo detectors and circuit devices by implanting impurities into a first surface of the second semiconductor layer, the first surface of the second semiconductor layer facing away from the first semiconductor layer, forming a wiring layer on the first surface of the second semiconductor layer, and forming a light filter layer on a second surface of the first semiconductor layer.