Method of forming through-silicon vias

1. A method of forming a semiconductor device, the method comprising:

providing a semiconductor substrate having the semiconductor device formed thereon;

forming a first dielectric layer on the semiconductor substrate;

forming a first interconnect feature in the first dielectric layer, the first interconnect feature being electrically coupled to the semiconductor device;

forming a second dielectric layer on the first dielectric layer;

forming a second interconnect feature in the second dielectric layer;

forming a stacking structure in the second dielectric layer;

removing the stacking structure, thereby forming a first recess in the second dielectric layer;

forming a second recess by extending the first recess into at least a portion of the semiconductor substrate; and

filling the second recess with a conductive material.

2. The method of claim 1 , wherein the second dielectric layer comprises a plurality of dielectric layers, each of the plurality of dielectric layers having a stacking structure, the stacking structure of the plurality of dielectric layers being in direct contact with a stacking structure in an adjacent dielectric layer of the plurality of dielectric layers.

3. The method of claim 2 , wherein the stacking structure comprises metal rings.

4. The method of claim 1 , further comprising forming a metal region on the first dielectric layer prior to the forming the second dielectric layer, the stacking structure being located directly over the metal region.

5. The method of claim 1 , wherein the forming the second interconnect feature in the second dielectric layer comprises forming a plurality of metal traces being electrically coupled to the semiconductor device.

6. The method of claim 1 , wherein the forming the second recess is performed at least in part by a first etch process removing the first dielectric layer at a bottom of the first recess, followed by a second etch process etching the semiconductor substrate.

7. The method of claim 1 , wherein the forming the second interconnect feature is performed simultaneously as the forming the stacking structure.

8. The method of claim 1 , wherein the conductive material comprises copper, tungsten, aluminum, cobalt, gold, silver, or combinations thereof.

9. A method of forming a semiconductor device, the method comprising:

providing a substrate;

forming a first dielectric layer over the substrate;

forming one or more second dielectric layers over the first dielectric layer, the one or more second dielectric layers having a sacrificial stacking structure extending therethrough;

removing the sacrificial stacking structure, thereby forming a first opening through the one or more second dielectric layers and exposing a portion of the first dielectric layer;

removing the first dielectric layer along a bottom of the first opening, thereby forming a second opening through the first dielectric layer and exposing an exposed portion of the substrate;

removing a portion of the substrate along a bottom of the second opening, thereby forming a recess in the substrate; and

filling the recess with a conductive material.

10. The method of claim 9 , wherein the sacrificial stacking structure comprises a stacking feature in each of the one or more second dielectric layers, each stacking feature comprising a first material, the first material having a different etch rate than material of the one or more second dielectric layers.

11. The method of claim 10 , wherein the first material is a metal.

12. The method of claim 9 , wherein the sacrificial stacking structure in each of the one or more second dielectric layers comprises a shape that completely separates a portion of the second dielectric layer from remaining portions of the second dielectric layer.

13. The method of claim 9 , further comprising forming a bottom layer over the first dielectric layer, the bottom layer being in contact with a lowest sacrificial stacking structure.

14. The method of claim 13 , wherein the forming the bottom layer is performed prior to the forming the one or more second dielectric layers.

15. A method of forming a semiconductor device, the method comprising:

providing a substrate;

forming a plurality of dielectric layers over the substrate;

forming a stacking structure in one or more of the plurality of dielectric layers, the stacking structure extending completely through at least one of the plurality of dielectric layers;

removing the stacking structure, thereby forming a recess extending through the one or more of the plurality of dielectric layers;

extending the recess into the substrate; and

filling the recess with a conductive material.

16. The method of claim 15 , wherein an inter-layer dielectric (ILD) layer is interposed between the plurality of dielectric layers and the substrate.

17. The method of claim 16 , wherein the extending the recess includes a first etching through the ILD layer and a second etching into the substrate.

18. The method of claim 15 , wherein each stacking structure includes a metal and a dielectric.

19. The method of claim 15 , wherein each stacking structure includes a metal shape surrounding another material in a plan view perspective.

20. The method of claim 15 , wherein each stacking structure has a wider portion over a narrower portion.