Interconnect structure and fabricating method thereof
An interconnect structure including a substrate, at least one ultra-thick metal (UTM) layer, a first dielectric layer and at least one pad metal layer is provided. The at least one UTM layer is disposed on the substrate. The first dielectric layer is disposed on the at least one UTM layer and exposes the at least one UTM layer. A stress of the first dielectric layer is −150 Mpa to −500 Mpa. The at least one pad metal layer is disposed on the first dielectric layer and electrically connected to the at least one UTM layer exposed by the first dielectric layer.
1. An interconnect structure, comprising:
a substrate;
at least one ultra-thick metal (UTM) layer disposed on the substrate;
a first dielectric layer disposed on the at least one UTM layer and exposing the at least one UTM layer, wherein the first dielectric layer is a plasma-enhanced chemical vapor deposition (PECVD) dielectric layer, and a stress of the PECVD dielectric layer is larger than or equal to −500 Mpa, and less than or equal to −420 Mpa; and
at least one pad metal layer disposed on the first dielectric layer and electrically connected to the at least one UTM layer exposed by the first dielectric layer.
2. The interconnect structure of claim 1 , wherein a material of the first dielectric layer comprises silicon oxide.
3. The interconnect structure of claim 1 , further comprising a blocking layer disposed between the first dielectric layer and the at least one UTM layer.
4. The interconnect structure of claim 3 , wherein a material of the blocking layer comprises silicon nitride.
5. The interconnect structure of claim 1 , wherein the number of the at least one UTM layer is plural, and the number of the at least one pad metal layer is plural.
6. The interconnect structure of claim 5 , further comprising a second dielectric layer disposed between the UTM layers.
7. The interconnect structure of claim 5 , further comprising a passivation layer structure disposed on a surface of an opening between the pad metal layers, wherein the passivation layer structure comprises:
a first passivation layer disposed on the surface of the opening between the pad metal layers; and
a second passivation layer disposed on the first passivation layer.
8. The interconnect structure of claim 7 , wherein the passivation layer structure further extends on a portion of the pad metal layers.
9. The interconnect structure of claim 7 , wherein a stress of the first passivation layer is −50 Mpa to −200 Mpa.
10. The interconnect structure of claim 7 , wherein a material of the first passivation layer comprises high density plasma-chemical vapor deposition (HDP-CVD) oxide.
11. The interconnect structure of claim 7 , wherein a material of the second passivation layer comprises silicon nitride.
12. A method of fabricating an interconnect structure, comprising:
forming at least one UTM layer on a substrate;
forming a first dielectric layer on the at least one UTM layer, wherein the first dielectric layer exposes the at least one UTM layer, the first dielectric layer is a plasma-enhanced chemical vapor deposition (PECVD) dielectric layer, and a stress of the PECVD dielectric layer is larger than or equal to −500 Mpa, and less than or equal to −420 Mpa; and
forming at least one pad metal layer on the first dielectric layer, wherein the at least one pad metal layer is electrically connected to the at least one UTM layer exposed by the first dielectric layer.
13. The method of fabricating the interconnect structure of claim 12 , wherein a method of forming the at least one UTM layer comprises a damascene method.
14. The method of fabricating the interconnect structure of claim 12 , wherein a method of forming the at least one pad metal layer comprises a combination of a deposition process, a lithography process, and an etching process.
15. The method of fabricating the interconnect structure of claim 12 , wherein the number of the at least one UTM layer is plural, and the number of the at least one pad metal layer is plural.
16. The method of fabricating the interconnect structure of claim 15 , further comprising forming a second dielectric layer between the UTM layers.
17. The method of fabricating the interconnect structure of claim 15 , further comprising forming a passivation layer structure on a surface of an opening between the pad metal layers, wherein the passivation layer structure comprises:
a first passivation layer disposed on the surface of the opening between the pad metal layers; and
a second passivation layer disposed on the first passivation layer.
18. The method of fabricating the interconnect structure of claim 17 , wherein a method of forming the first passivation layer comprises a HDP-CVD method.