Hybrid dual damascene structures with enlarged contacts
Structures for field-effect transistors and methods for fabricating a structure for field-effect transistors. A contact structure is formed that includes a first contact arranged over a source/drain region and a second contact arranged over the first contact. A dielectric cap is formed over the second contact. A via is formed that extends in a vertical direction through the dielectric cap to the second contact. An interconnect is formed over the dielectric cap, and is connected by the via with the second contact.
1. A structure comprising:
a first source/drain region;
an interlayer dielectric layer having a top surface,
a contact structure including a first contact over the first source/drain region and a second contact over the first contact;
a dielectric cap over the second contact;
a first interconnect over the dielectric cap; and
a via extending in a vertical direction through the dielectric cap to the second contact, the via connecting the first interconnect with the second contact,
wherein the second contact and the dielectric cap are embedded in the interlayer dielectric layer in a stack, and the dielectric cap is coplanar with the top surface of the interlayer dielectric layer.
2. The structure of claim 1 wherein the first contact has a first width in a lateral direction, and the second contact has a second width in the lateral direction that is greater than the first width.
3. The structure of claim 1 further comprising:
a second interconnect over the second contact,
wherein the dielectric cap isolates the second interconnect from the second contact.
4. The structure of claim 1 further comprising:
a second source/drain region,
wherein the first contact straps the first source/drain region with the second source/drain region.
5. The structure of claim 1 wherein the first contact is comprised of a metal silicide, and the second contact is comprised of a metal.
6. The structure of claim 1 wherein the second contact is offset laterally from the first contact and the first source/drain region such that the second contact and the first contact are not centered.
7. The structure of claim 1 wherein the first contact has a first width in a lateral direction transverse to the vertical direction, and the dielectric cap has a second width in the lateral direction that is substantially equal to the first width.
8. The structure of claim 1 wherein the first interconnect is not directly over the first contact.
9. A structure comprising:
a first source/drain region;
a contact structure including a first contact over the first source/drain region and a second contact over the first contact;
a dielectric cap over the second contact;
a first interconnect over the dielectric cap; and
a via extending in a vertical direction through the dielectric cap to the second contact, the via connecting the first interconnect with the second contact,
wherein the second contact is offset laterally from the first contact and the first source/drain region such that the second contact and the first contact are not centered.
10. The structure of claim 9 wherein the first interconnect is not directly over the first contact.
11. The structure of claim 9 wherein the first contact has a first width in a lateral direction, and the second contact has a second width in the lateral direction that is greater than the first width.
12. The structure of claim 9 further comprising:
a second interconnect over the second contact,
wherein the dielectric cap isolates the second interconnect from the second contact.
13. The structure of claim 9 further comprising:
a second source/drain region,
wherein the first contact straps the first source/drain region with the second source/drain region.
14. The structure of claim 9 wherein the first contact is comprised of a metal silicide, and the second contact is comprised of a metal.
15. A structure comprising:
a first source/drain region;
a contact structure including a first contact over the first source/drain region and a second contact over the first contact;
a dielectric cap over the second contact;
a first interconnect over the dielectric cap; and
a via extending in a vertical direction through the dielectric cap to the second contact, the via connecting the first interconnect with the second contact,
wherein the first contact has a first width in a lateral direction transverse to the vertical direction, and the dielectric cap has a second width in the lateral direction that is substantially equal to the first width.
16. The structure of claim 15 wherein the first interconnect is not directly over the first contact.
17. The structure of claim 15 wherein the first contact has a third width in the lateral direction, and the second contact has a fourth width in the lateral direction that is greater than the third width.
18. The structure of claim 15 further comprising:
a second interconnect over the second contact,
wherein the dielectric cap isolates the second interconnect from the second contact.
19. The structure of claim 15 further comprising:
a second source/drain region,
wherein the first contact straps the first source/drain region with the second source/drain region.
20. The structure of claim 15 wherein the first contact is comprised of a metal silicide, and the second contact is comprised of a metal.