Patent ID: 8193023

Claim:
A method for manufacturing a unit pixel of an image sensor having a three-dimensional structure, including a first chip and a second chip which are stacked, one of the first chip and the second chip having a photodiode and the other of the first chip and the second chip having a circuit for receiving information from the photodiode and outputting received information, the method comprising the steps of: (a) preparing the first chip including a first pad which is disposed on and projected out from an upper surface of the first chip in such a way as to define a concavo-convex structure and the second chip including a second pad which is disposed on and depressed into an upper surface of the second chip in such a way as to define a concavo-convex structure corresponding to the concavo-convex structure of the first chip; (b) facing the first pad of the first chip and the second pad of the second chip; (c) aligning the first chip and the second chip such that the first pad of the first chip and the second pad of the second chip are mated with each other; and (d) bonding the first pad of the first chip and the second pad of the second chip which are mated with each other.