Interconnect structure having substractive etch feature and damascene feature
View Patent ↗Methods of forming an interconnect structure include depositing a first conductive material on a substrate. Aspects include subtractively etching the conductive material to form a patterned first conductive layer, and depositing a dielectric layer on interconnect structure. Aspects also include depositing a second conductive material on the dielectric layer and removing the second conductive material through the top of the second metal liner.
1. An interconnect structure comprising:
a first layer comprising:
a first insulator layer;
a first dielectric layer on the first insulator layer;
a subtractive etch feature comprising a first conductive material, the subtractive etch feature having a first subtractive etch vertical wall, a second subtractive etch vertical wall, and an angle between the first subtractive etch vertical wall and a horizontal plane that is less than 90 degrees; and
a damascene feature comprising a second conductive material, the damascene feature having a first damascene vertical wall, a second damascene vertical wall, and an angle between the first damascene vertical wall and the horizontal plane that is greater than 90 degrees;
wherein the first subtractive etch vertical wall is parallel to the second damascene vertical wall; and
a second layer comprising:
a second insulator layer; and
a metal feature; and
a conductive via that extends from the second layer to the first layer.
2. The interconnect structure according to claim 1 , wherein the metal feature comprises a second subtractive etch feature, the second subtractive etch feature comprising a third conductive material, the second subtractive etch feature having a third subtractive etch vertical wall, a fourth subtractive etch vertical wall, and an angle between the third subtractive etch vertical wall and the horizontal plane that is less than 90 degrees.
3. The interconnect structure according to claim 2 , wherein the conductive via that extends from the second layer to the first layer underlies the second subtractive etch feature.
4. The interconnect structure according to claim 1 , wherein the metal feature comprises a second damascene feature, the second damascene feature comprising a third damascene vertical wall, a fourth damascene vertical wall, and an angle between the third damascene vertical wall and the horizontal plane that is greater than 90 degrees.
5. The interconnect structure according to claim 1 , further comprising a third dielectric layer on top of the second insulator layer.
6. The interconnect structure according to claim 5 , further comprising a fourth dielectric layer.
7. The interconnect structure according to claim 1 , further comprising a metal liner.
8. The interconnect structure according to claim 7 , wherein the metal feature is lined with the metal liner.
9. The interconnect structure according to claim 7 , wherein the subtractive etch feature is lined with the metal liner.
10. The interconnect structure according to claim 7 , wherein the damascene structure is lined with the metal liner.
11. The interconnect structure according to claim 1 , wherein the first dielectric layer has a dielectric constant less than or equal to 4.
12. The interconnect structure according to claim 1 , wherein the first dielectric layer comprises silicon dioxide.
13. The interconnect structure according to claim 1 , wherein the first dielectric layer comprises carbon doped oxide.
14. The interconnect structure according to claim 1 , wherein the first dielectric layer is a composite layer.
15. The interconnect structure according to claim 14 , wherein the first dielectric layer comprises an adhesion layer.
16. The interconnect structure according to claim 14 , wherein the first dielectric layer comprises an etch stop layer.
17. The interconnect structure according to claim 14 , wherein the first dielectric layer comprises nitrogen.
18. The interconnect structure according to claim 14 , wherein the first dielectric layer comprises a porous layer.
19. The interconnect structure of claim 1 , further comprising a second via.
20. The interconnect structure of claim 19 , wherein the second via extends from the first dielectric layer through the first insulator layer to a third layer.