Electrical and optical via connections on a same chip
The present disclosure relates to semiconductor structures and, more particularly, to electrical and optical via connections on a same chip and methods of manufacture. The structure includes an optical through substrate via (TSV) comprising an optical material filling the TSV. The structure further includes an electrical TSV which includes a liner of the optical material and a conductive material filling remaining portions of the electrical TSV.
1. A method, comprising:
forming an optical through substrate via (TSV) in a substrate comprising:
forming an annular via around a core portion comprised of a portion of the substrate, wherein the annular via has a via width “d 1 ” between an inner wall of the annular via adjacent to the core portion and an outer wall of the annular via spaced apart from the core portion, and wherein a circumferential dimension of the core portion is “d 2 ”; and
filling an optical material in the annular via; and
forming an airgap in the substrate in alignment with the optical TSV; and
forming an electrical TSV in the substrate comprising:
forming a via in the substrate, spaced apart from the annular via;
forming a liner of the optical material on sidewalls of the via; and
forming an electrically conductive material in remaining portions of the via, wherein the electrical TSV has a diameter of “D 1 ”, where D 1 >d 1 .
2. The method of claim 1 , wherein the substrate is silicon and the optical TSV and the electrical TSV are through the silicon vias.
3. The method of claim 1 , wherein the optical material is oxide material.
4. The method of claim 1 , wherein the electrical TSV is via shape.
5. The method of claim 4 , wherein a width dimension of the optical TSV is smaller than a width dimension of the electrical TSV.
6. The method of claim 4 , wherein the optical TSV and the electrical TSV extend entirely through the substrate.
7. The method of claim 4 , further comprising forming at least one additional device in the substrate spaced apart from the optical TSV and the electrical TSV.
8. The method of claim 1 , wherein the airgap is formed by recessing the optical material and the core portion in the substrate.
9. The method of claim 8 , further comprising forming a photodetector in alignment with the airgap and the optical TSV.
10. The method of claim 9 , wherein the airgap spans the core portion and overlaps with the optical material filling the TSV of the optical TSV.
11. The method of claim 10 , wherein the photodetector is provided in another substrate which is bonded to the substrate having the optical TSV.
12. The method of claim 11 , further comprising bonding the another substrate having the photodetector to the substrate having the optical TSV using an oxide-oxide bond.
13. The method of claim 12 , wherein the another substrate includes an electrical TSV which electrically contacts the electrical TSV of the substrate having the optical TSV.