Patent ID: 8519499
Filing Date: 2013-08-27
Classification: H01L

Abstract:
1. A solid-state image sensor comprising: a semiconductor substrate including a first surface on which light enters, and a second surface opposite to the first surface; a pixel region formed in the semiconductor substrate, and including a photoelectric conversion element which converts the incident light into an electrical signal; a peripheral region formed in the semiconductor substrate, and including a circuit which controls an operation of the element in the pixel region; a plurality of interconnects which are formed in a plurality of interlayer insulating films stacked on the second surface, and are connected to the circuit; and a support substrate formed on the stacked interlayer insulating films and the interconnects; an electrode provided in the semiconductor substrate and extending through the peripheral region from the first surface to the second surface, one end of the electrode connected to a pad on the first surface and an other end of the electrode connected to the circuit on the second surface; and at least one of dummy layers formed in the plurality of interlayer insulating films stacked on the second surface, and not connected to the circuit, the dummy layers provided in a low-coverage region in the interlayer insulating films above at least one of the pixel region and a peripheral region, wherein an uppermost one of the interconnects formed in an uppermost one of the interlayer insulating films is buried in a first trench formed in the uppermost interlayer insulating film, wherein an uppermost one of the dummy layer formed in the uppermost interlayer insulating film is buried in a second trench formed in the uppermost interlayer insulating film, and wherein a material used as the uppermost interconnect and the uppermost dummy layer are selected from the group consisting of copper and an alloy of copper.