Image sensor and method for manufacturing the same
An image sensor includes a metal interconnection and readout circuitry over a first substrate, an image sensing device, and an ion implantation isolation layer. The image sensing device is over the metal interconnection, and an ion implantation isolation layer is in the image sensing device. The image sensing device includes first, second and third color image sensing units, and ion implantation contact layers. The first, second and third color image sensing units are stacked in or on a second substrate. The ion implantation contact layers are electrically connected to the first, second and third color image sensing units, respectively.
1. An image sensor comprising:
a metal interconnection and readout circuitry over a first substrate;
an image sensing device over the metal interconnection; and
an ion implantation isolation layer in the image sensing device,
wherein the image sensing device comprises:
first, second and third color image sensing units stacked in or on a second substrate; and
ion implantation contact layers electrically connected to the first, second and third color image sensing units, respectively.
2. The image sensor of claim 1 , wherein the ion implantation contact layer extends through the ion implantation isolation layer.
3. The image sensor of claim 1 , wherein the ion implantation isolation layer in the image sensing device comprises a first horizontal ion implantation isolation layer between first and second color image sensing units, and a second horizontal ion implantation isolation layer between second and third color image sensing units.
4. The image sensor of claim 3 , wherein the ion implantation isolation layer in the image sensing device further comprises a vertical ion implantation isolation layer at an interface between pixels of each of the first, second and third color image sensing units.
5. The image sensor of claim 1 , further comprising:
a dielectric between the first substrate and the image sensing device; and
a metal over the dielectric, the metal being electrically connected to the ion implantation contact layer.
6. The image sensor of claim 1 , wherein the readout circuitry comprises an electrical junction region over the first substrate,
the electrical junction region comprising:
a first conduction type ion implantation region in the first substrate; and
a second conduction type ion implantation region over the first conduction type ion implantation region.
7. The image sensor of claim 6 , further comprising a first conduction type connection region over the electrical junction region, the first conduction type connection region being electrically connected to the metal interconnection.
8. The image sensor of claim 1 , wherein the readout circuitry comprises a transistor having a potential difference between a source and a drain thereof.
9. The image sensor of claim 8 , wherein the transistor comprises a transfer transistor, and the source of the transistor has an ion implantation concentration lower than a floating diffusion region.
10. The image sensor of claim 6 , further comprising a first conduction type connection region formed spaced from the electrical junction region and electrically connected to the metal interconnection.