Patent ID: 8193022

Claim:
A method of manufacturing a back side illumination image sensor, comprising: forming an ion implantation layer in a front side of a first substrate; forming a photosensitive device and a readout circuit on the front side of the first substrate above where the ion implantation layer is formed; forming an interlayer dielectric layer on the front side of the first substrate over the photosensitive device and the readout circuit; forming a metal line and a pad metal line on the interlayer dielectric layer; bonding a second substrate with the front side of the first substrate over the metal line and pad metal line; and removing a lower part of the first substrate under the ion implantation layer; wherein a first metal of the metal line and a pad of the pad metal line are formed at the same metal level, in the forming of the metal line and the pad metal line; and wherein the pad is formed to have a step, in the forming of the pad of the pad metal line.