Semiconductor with through-substrate interconnect
Semiconductor devices are described that have a metal interconnect extending vertically through a portion of the device to the back side of a semiconductor substrate. A top region of the metal interconnect is located vertically below a horizontal plane containing a metal routing layer. Method of fabricating the semiconductor device can include etching a via into a semiconductor substrate, filling the via with a metal material, forming a metal routing layer subsequent to filling the via, and removing a portion of a bottom of the semiconductor substrate to expose a bottom region of the metal filled via.
1. A semiconductor device comprising:
a silicon substrate having a first side and a second side;
a conductive interconnect extending from a first side toward a second side of the silicon substrate, the conductive interconnect having a first end proximate the first side of the silicon substrate and a second end proximate the second side of the silicon substrate;
a first dielectric structure proximate the first side of the silicon substrate;
a first metal routing structure at the first dielectric structure, the first metal routing structure being at least partially in the first dielectric structure;
a second dielectric structure having at least a first opening generally corresponding to the first metal routing structure, a second opening generally corresponding to the conductive interconnect, and a third opening; and
a first conductive portion in the first opening, a second conductive portion in the second opening, and a second metal routing structure in the third opening.
2. The semiconductor device of claim 1 further including:
a transistor having a gate and source/drain implant regions in the silicon substrate;
an insulating material on the silicon substrate;
a contact extending through the insulating material to the transistor, the contact having a first end proximate the gate and source/drain implant regions of the transistor and a second end opposite the first end; and
wherein the conductive interconnect is laterally spaced apart from the transistor and extends deeper into the silicon substrate than the source/drain implant regions of the transistor.
3. The semiconductor device of claim 1 wherein the second opening includes a plurality of openings generally corresponding to the conductive interconnect.
4. The semiconductor device of claim 1 wherein the first metal routing structure is laterally spaced apart from the conductive interconnect.
5. The semiconductor device of claim 1 wherein the conductive interconnect has a cross-sectional shape that is one of a circle, oval, square, diamond or rectangle.
6. The semiconductor device of claim 1 wherein the first dielectric structure comprises at least a first layer, a second layer and a third layer, where the first layer is proximate the first side of the silicon substrate, the third layer is proximate the second side of the silicon substrate and the second layer is located between the first layer and the third layer.
7. The semiconductor device of claim 1 , further comprising:
a first barrier layer at a top surface of conductive interconnect;
an oxide layer at the first barrier layer; and
a second barrier layer at the oxide layer.
8. The semiconductor device of claim 1 wherein:
the conductive interconnect extends vertically through a portion of the semiconductor device to the second side of the semiconductor device; and
a top region of the conductive interconnect is located vertically below a horizontal plane containing the second metal structure.
9. The semiconductor device of claim 1 wherein the first metal routing structure forms an electrically conductive contact with the conductive interconnect.
10. The semiconductor device of claim 1 wherein the second metal routing structure forms an electrically conductive contact with the conductive interconnect.
11. The semiconductor device of claim 1 , further comprising a conductive redistribution structure at the second side of the semiconductor device, wherein the conductive redistribution structure is electrically coupled to the conductive interconnect.