Image sensor with stacked structures
Provided is an image sensor, which includes: a first substrate; a first structure on a front surface of the first substrate, the first structure including a first interlayer insulating layer surrounding a first conductive layer; a second substrate; a second structure on a front surface of the second substrate facing the front surface of the first substrate, the second structure including a second interlayer insulating layer, the second interlayer insulating layer being bonded to the first interlayer insulating layer; an organic photoelectric layer on a back surface of the second substrate; and a via electrode structure in contact with the first conductive layer through the second substrate and the second structure, the via electrode structure including an air gap therein.
1. An image sensor comprising:
a first substrate;
a first structure on a front surface of the first substrate, wherein the first structure comprising a first interlayer insulating layer including a first conductive layer;
a second substrate;
a second structure on a front surface of the second substrate facing the front surface of the first substrate, the second structure comprising a second interlayer insulating layer, the second interlayer insulating layer being bonded to the first interlayer insulating layer;
an organic photoelectric layer on a back surface of the second substrate; and
a via electrode structure in contact with the first conductive layer through the second substrate and the second structure, wherein the via electrode structure comprising an air gap therein.
2. The image sensor of claim 1 , wherein the via electrode structure comprises:
an electrode conductive layer on an inner wall of a via electrode hole penetrating the second substrate and the second structure; and
an electrode filling layer on the electrode conductive layer, the electrode filling layer filling a portion of the via electrode hole, and comprising the air gap.
3. The image sensor of claim 2 , further comprising:
a color filter layer under the organic photoelectric layer; and
a first cover insulating layer on the color filter layer,
wherein the electrode filling layer and the first cover insulating layer include an identical material on an identical level.
4. The image sensor of claim 3 , wherein a level of a top surface of the electrode filling layer is identical to, or lower than, a level of a bottom surface of the organic photoelectric layer.
5. The image sensor of claim 2 , further comprising an electrode liner between the electrode conductive layer and the electrode filling layer.
6. The image sensor of claim 2 , wherein a level of an uppermost surface of the air gap is higher than a level of an uppermost surface of the electrode conductive layer.
7. The image sensor of claim 1 , wherein the air gap extends from the second substrate to the second interlayer insulating layer.
8. The image sensor of claim 1 , wherein the air gap extends from the second substrate to the first interlayer insulating layer.
9. The image sensor of claim 1 , wherein the second structure on the second substrate further comprises a second conductive layer, wherein the via electrode structure is in contact with the second conductive layer.
10. The image sensor of claim 9 , wherein the first conductive layer comprises at least two stacked conductive layers, and the via electrode structure is in contact with the at least two stacked conductive layers.
11. An image sensor comprising:
a first substrate comprising a first interlayer insulating layer;
a second substrate comprising a second interlayer insulating layer;
a color filter layer on the second substrate;
an organic photoelectric layer on the color filter layer;
a via electrode hole penetrating the second substrate and the second interlayer insulating layer, wherein the via electrode hole being in contact with the first interlayer insulating layer; and
a via electrode structure in the via electrode hole, wherein the via electrode structure comprises:
an electrode conductive layer comprising a conductive material; and
an electrode filling layer on the electrode conductive layer, wherein the electrode filling layer comprising an air gap at a central portion thereof and an insulating material.
12. The image sensor of claim 11 , wherein the electrode conductive layer comprises tungsten (W) or a tungsten alloy, and the insulating material comprises at least one of tetraethyl orthosilicate (TEOS) or plasma enhanced-TEOS (PE-TEOS).
13. The image sensor of claim 11 , wherein the air gap is encapsulated by the electrode filling layer.
14. The image sensor of claim 11 , further comprising a first cover insulating layer on the color filter layer, wherein the first cover insulating layer comprises an identical material at an identical level as the electrode filling layer.
15. The image sensor of claim 13 , the air gap extends from the second substrate to the second interlayer insulating layer.
16. An image sensor comprising:
a first substrate comprising a first via electrode region and an element region including a logic device;
a first interlayer insulating layer on a front surface of the first substrate, wherein the first interlayer insulating layer comprising a first conductive layer in the first via electrode region;
a second substrate comprising a second via electrode region and a pixel region including a photoelectric conversion element;
a second interlayer insulating layer on a front surface of the second substrate facing the front surface of the first substrate, wherein the second interlayer insulating layer being bonded to the first interlayer insulating layer;
a bottom transparent electrode layer on a back surface of the second substrate, the bottom transparent electrode layer corresponding to the photoelectric conversion element;
a top transparent electrode layer on the back surface of the second substrate;
an organic photoelectric layer between the top transparent electrode layer and the bottom transparent electrode layer; and
a via electrode structure penetrating the second substrate and the second interlayer insulating layer in the second via electrode region to contact the first conductive layer in the first via electrode region, wherein the via electrode structure comprising an air gap therein.
17. The image sensor of claim 16 , wherein the via electrode structure comprises:
an electrode conductive layer penetrating the second substrate and the second interlayer insulating layer in the second via electrode region, the electrode conductive layer on an inner wall of a via electrode hole extending to the first via electrode region; and
an electrode filling layer on the electrode conductive layer, the electrode filling layer filling a portion of the via electrode hole, and comprising the air gap.
18. The image sensor of claim 17 , wherein a top surface of the electrode filling layer is a flat surface, and a level of the top surface of the electrode filling layer is higher than a level of a top surface of the electrode conductive layer.
19. The image sensor of claim 17 , wherein a bottom surface of the electrode conductive layer has a concavo-convex shape comprising at least one protruding portion.
20. The image sensor of claim 17 , wherein the electrode conductive layer comprises a first side wall and a second side wall, both the first side wall and the second side wall of the electrode conductive layer have a tapered shape, wherein the first side wall has a flat shape, and the second side wall has a step shape.