Reliable interconnect for semiconductor device
View Patent ↗Semiconductor devices and methods of making thereof are disclosed. The semiconductor device includes a substrate prepared with a first dielectric layer formed thereon. The dielectric layer includes at least first, second and third contact regions. A second dielectric layer is disposed over the first dielectric layer. The device also includes at least first, second and third via contacts disposed in the second dielectric layer. The via contacts are coupled to the respective underlying contact regions and the via contacts do not extend beyond the underlying contact regions.
1. A method for forming a device comprising:
providing a substrate prepared with a first dielectric layer formed thereon, wherein the dielectric layer comprises at least first, second and third contact regions;
forming a second dielectric layer over the first dielectric layer;
forming a conductive mask layer having top and bottom planar surfaces on and contacts the second dielectric layer;
patterning the conductive mask layer to form at least first, second and third conductive mask openings without using a mask; and
forming at least first, second and third via contacts in the second dielectric layer, wherein the via contacts are coupled to the respective underlying contact regions and the via contacts do not extend beyond the underlying contact regions.
2. The method of claim 1 wherein the conductive mask layer comprises a metal material having a faster etch rate when in proximity with conductive material versus non-conductive material.
3. A method for forming a device comprising:
providing a substrate prepared with a first dielectric layer formed thereon, wherein the dielectric layer comprises at least first, second and third contact regions;
forming a second dielectric layer over the first dielectric layer;
forming a conductive mask layer over the second dielectric layer, wherein the conductive mask layer comprises Ta, the contact regions comprise copper and the second dielectric layer comprises NBlok; and
forming at least first, second and third via contacts in the second dielectric layer, wherein the via contacts are coupled to the respective underlying contact regions and the via contacts do not extend beyond the underlying contact regions.
4. The method of claim 2 wherein the metal material comprises Ta, alloy or a combination thereof.
5. The method of claim 1 wherein the conductive mask layer is patterned using a blanket etch technique.
6. The method of claim 1 wherein the first, second and third conductive mask openings are self-aligned with the first, second and third contact regions.
7. The method of claim 1 comprising forming a patterned soft mask having at least first, second and third openings over the conductive mask layer having the conductive mask openings.
8. The method of claim 7 wherein the first soft mask opening is misaligned with the underlying first opening of the conductive mask layer, the second soft mask opening is wider than the underlying second opening of the conductive mask layer and the third soft mask opening is narrower than the underlying third opening of the conductive mask layer.
9. The method of claim 8 comprising removing portions of the second dielectric layer unprotected by the soft mask or the conductive mask layer to form at least first, second and third via openings.
10. The method of claim 9 wherein the first via opening comprises a first sidewall which is aligned with first sidewall of the first conductive mask opening and a second sidewall which is aligned with second sidewall of the first soft mask opening.
11. The method of claim 9 wherein the second via opening comprises first and second sidewalls which are aligned with first and second sidewalls of the second conductive mask opening.