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 method of fabricating a semiconductor device comprising:
etching a via into a silicon substrate from a first side toward a second side of the silicon substrate;
forming an insulating material in the etched via;
forming a seed material on the insulating material;
blocking selected regions of the seed material located outside of the via with a photoresist;
plating exposed regions of the seed material to fill the via with a conductive material, thereby forming a conductive interconnect in the etched via, 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;
insulating the conductive interconnect with a dielectric material proximate the first side of the silicon substrate; and
forming a metal routing structure on the dielectric material, the metal routing structure being at least partially in the dielectric material.
2. The method of claim 1 wherein:
the method further includes:
fabricating a transistor having a gate and source/drain implant regions in the silicon substrate;
forming an insulating material on the silicon substrate with the fabricated transistor;
forming a contact extending through the insulating material to the transistor; and
etching the via includes etching a via through the dielectric material and into the silicon substrate laterally adjacent to the transistor, the via extending deeper into the silicon substrate than the source/drain implant regions of the transistor.
3. The method of claim 1 wherein:
the method further includes:
fabricating a transistor having a gate and source/drain implant regions in the silicon substrate;
forming an insulating material on the silicon substrate with the fabricated transistor;
forming 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;
etching the via includes etching a via through the dielectric material and into the silicon substrate laterally adjacent to the transistor, the via extending deeper into the silicon substrate than the source/drain implant regions of the transistor; and
forming the metal routing structure includes:
forming an opening in the dielectric material, the opening exposing the second end of the contact and being laterally spaced apart from the via; and
filling the opening with a conductive material.
4. The method of claim 1 , further comprising:
removing a portion of the second side of the silicon substrate to expose the second end of the conductive interconnect; and
forming a conductive redistribution structure proximate the second side of the silicon substrate, the conductive redistribution structure being in electrical communication with the conductive interconnect.
5. The method of claim 1 wherein:
the metal routing structure is a first metal routing structure;
the dielectric material is a first dielectric material;
the method further includes:
insulating the conductive interconnect and the first metal routing structure with a second dielectric material;
forming a plurality of openings in the second dielectric material, the openings including a first opening generally corresponding to the first metal routing structure, a second opening generally corresponding to the conductive interconnect, and a third opening generally corresponding to a second metal routing structure; and
filling the plurality of openings with a conductive material, thereby forming a first conductive path between the first and second metal routing structures, a second conductive path between the second metal routing structure and the conductive interconnect, and the second metal routing structure.
6. The method of claim 5 wherein the second opening includes a plurality of openings generally corresponding to the conductive interconnect.
7. The method of claim 5 wherein the first metal routing structure is laterally spaced apart from the conductive interconnect.
8. The method of claim 1 , further including:
fabricating a transistor having a gate and source/drain implant regions in the silicon substrate;
forming an insulating material on the silicon substrate with the fabricated transistor; and
forming 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.
9. The method of claim 1 wherein etching the via includes etching a via through the dielectric material and into the silicon substrate laterally adjacent to an electronic device, the via extending deeper into the silicon substrate than a source/drain implant region of the electronic device.
10. The method of claim 1 wherein:
the metal routing structure is a first metal routing structure;
the dielectric material is a first dielectric material; and
the method further includes:
insulating the conductive interconnect and the first metal routing structure with a second dielectric material;
forming a plurality of openings in the second dielectric material, the openings including a first opening generally corresponding to the first metal routing structure, a second opening generally corresponding to the conductive interconnect, and a third opening generally corresponding to a second metal routing structure.
11. A method of fabricating a semiconductor device comprising:
etching a via into a silicon substrate from a first side toward a second side of the silicon substrate;
forming a conductive interconnect in the etched via, 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;
insulating the conductive interconnect with a dielectric material proximate the first side of the silicon substrate;
forming a metal routing structure on the dielectric material, the metal routing structure being at least partially in the dielectric material;
fabricating a transistor having a gate and source/drain implant regions in the silicon substrate;
forming an insulating material on the silicon substrate with the fabricated transistor;
forming 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:
etching the via includes etching a via through the dielectric material and into the silicon substrate laterally adjacent to the transistor, the via extending deeper into the silicon substrate than the source/drain implant regions of the transistor; and
forming the metal routing structure includes:
forming an opening in the dielectric material, the opening exposing the second end of the contact and being laterally spaced apart from the via; and
filling the opening with a conductive material.