Capacitor for integration with copper damascene processes and a method of manufacture therefore
View Patent ↗The present invention provides a capacitor for use in a semiconductor device having a damascene interconnect structure, such as a dual damascene interconnect, formed over a substrate of a semiconductor wafer. In one particularly advantageous embodiment, the capacitor, comprises a first capacitor electrode, such as copper, comprised of a portion of the damascene interconnect structure, an insulator layer formed on the damascene interconnect structure wherein the insulator layer is a passivation layer, such as silicon nitride. The passivation layer may be an outermost or final passivation layer, or it may be an interlevel passivation layer. The capacitor further includes a second capacitor electrode comprised of a conductive layer, such as aluminum, that is formed on at least a portion of the insulator layer.
1. For use in a semiconductor device having a damascene interconnect structure formed over a substrate of a semiconductor wafer, a capacitor, comprising:
a first capacitor electrode comprised of a portion of a damascene interconnect structure;
an insulator layer located on a single plane and on the damascene interconnect structure; and
a second capacitor electrode comprised of a conductive layer formed on at least a portion of the insulator layer, wherein the conductive layer extends over an interconnect structure located on a same level as the first capacitor electrode, the interconnect structure not forming a portion of a capacitor, wherein an upper surface of the conductive layer defines a single plane.
2. The capacitor as recited in claim 1 wherein the capacitor is a metal-insulator-metal (MIM) capacitor.
3. The capacitor as recited in claim 1 wherein the insulator layer is silicon nitride.
4. The capacitor as recited in claim 1 wherein the first capacitor electrode comprises copper and the second capacitor electrode comprises aluminum.
5. The capacitor as recited in claim 1 wherein the insulator layer is tantalum pentoxide.
6. The capacitor as recited in claim 1 wherein the damascene interconnect structure comprises a plurality of interconnect structures electrically isolated from each other by a dielectric material, the insulator layer formed on each of the plurality of interconnect structures.
7. The capacitor as recited in claim 1 wherein the damascene interconnect is an outermost damascene interconnect structure, the insulator layer is an outermost capping layer and the second capacitor electrode comprises a portion of an outermost conductive layer formed on at least a portion of the insulator layer.
8. A method of fabricating a capacitor for use in a semiconductor device having a damascene interconnect structure formed over a substrate of a semiconductor wafer, comprising:
forming a first capacitor electrode comprised of a portion of a damascene interconnect structure;
forming an insulator layer on a single plane and on the damascene interconnect structure; and
forming a second capacitor electrode comprised of a conductive layer formed on at least a portion of the insulator layer, wherein the conductive layer extends over an interconnect structure located on a same level as the first capacitor electrode, the interconnect structure not forming a portion of a capacitor, wherein an upper surface of the conductive layer defines a single plane.
9. The method as recited in claim 8 wherein fabricating the capacitor includes fabricating a metal-insulator-metal (MIM) capacitor.
10. The method as recited in claim 8 wherein forming an insulator layer includes forming a silicon nitride layer.
11. The method as recited in claim 8 wherein forming the first capacitor electrode includes forming the first capacitor electrode with copper and forming the second capacitor electrode includes forming the second capacitor electrode with aluminum.
12. The method as recited in claim 8 wherein forming an insulator layer includes forming an insulator comprising tantalum pentoxide.
13. The method as recited in claim 8 wherein forming a damascene interconnect structure includes forming a plurality of interconnect structures electrically isolated from each other by a dielectric material and forming an insulator layer includes forming an insulator layer on each of the plurality of interconnect structures.
14. The method as recited in claim 8 wherein forming a damascene interconnect structure includes forming an outermost damascene interconnect structure, forming an insulator layer includes forming an outermost capping layer and forming a conductive layer includes forming an outermost conductive layer on at least a portion of the insulator layer.
15. The method as recited in claim 14 wherein forming a conductive layer includes forming a bond pad from a portion of the conductive layer.
16. The method as recited in claim 8 wherein forming the semiconductor device includes forming a CMOS device.
17. The method as recited in claim 8 further comprising forming a dielectric layer over the capacitor and planarizing the dielectric layer to a substantial planar surface.
18. The capacitor as recited in claim 1 wherein the second capacitor electrode is a second damascene capacitor electrode.