Formation of liner and metal conductor
An integrated circuit device includes a substrate including a dielectric layer patterned with a set of conductive line trenches, each conductive line trench having parallel vertical sidewalls and a horizontal bottom. A liner which is an alloy of a first metal and a selected element formed at interfaces of the metal layer and a surface of the dielectric and is created by an anneal and reflow process. The first metal having a first conductivity in a pure form. A second metal layer fills the set of conductive line trenches, the second metal having a second conductivity higher than the first conductivity.
1. An integrated circuit device comprising:
a substrate including a dielectric layer patterned with a set of conductive line trenches, each conductive line trench having parallel vertical sidewalls and a horizontal bottom, wherein the vertical sidewalls and horizontal bottoms have an element enriched surface layer in which a concentration of a selected element is increased relative to a remainder of the dielectric layer;
a liner which is an alloy of a first metal and the selected element, the liner formed in the element enriched surface layer of the dielectric layer, the first metal having a first conductivity in a pure form, the liner being a first barrier layer; and
a second metal layer comprised of a second metal, the second metal layer in contact with the liner formed in the dielectric layer, the second metal layer entirely filling the set of conductive line trenches, the second metal having a second conductivity higher than the first conductivity.
2. The device as recited in claim 1 wherein the first metal is aluminum and the selected element is nitrogen.
3. The device as recited in claim 2 , wherein the liner is comprised of an alloy selected from the group consisting of AlN and Al(N, Si), and Al(N, Si, Mn).
4. The device as recited in claim 1 , wherein the first metal is comprised of a metal selected from the group consisting of Al, Co, Ru, Ir, Rh, W, Mn and Ni.
5. The device as recited in claim 1 , wherein the selected element is selected from the group consisting of N, Si, C, and O.
6. The device as recited in claim 1 , wherein the second metal layer in the set of conductive lines trenches has a top surface which is coplanar with a top surface of the dielectric in field areas of the dielectric layer.
7. The device as recited in claim 1 wherein the liner is comprised of an alloy AB wherein A is a metal selected from the group consisting of Al, Co, Ru, Ir, Rh, Mn, Ni and B is a selected element selected from the group consisting of N, Si, C, and O.
8. The device as recited in claim 1 further comprised of a second barrier layer disposed between the liner and the second metal layers.
9. The device as recited in claim 1 wherein the liner is further comprised of a manganese alloy.
10. An integrated circuit device comprising:
a substrate including a dielectric layer patterned with a set of conductive line trenches, each conductive line trench having parallel vertical sidewalls and a horizontal bottom, wherein the vertical sidewalls and horizontal bottom have an element enriched surface layer in which the concentration of a selected element is increased relative to a remainder of the dielectric layer;
a liner which is an alloy of a first metal and the selected element, the liner formed in the element enriched surface layer of the dielectric layer, the first metal having a first conductivity in a pure form; and
a second metal layer in contact with the liner formed in the dielectric layer and filling the set of conductive line trenches, the second metal layer having a rectangular cross-section and a top surface coplanar with a top surface of the dielectric layer, the second metal having a second conductivity higher than the first conductivity.
11. The device as recited in claim 10 , wherein the liner is a barrier layer to diffusion.
12. The device as recited in claim 10 , wherein each of the set of conductive lines is formed from a single layer of the second metal.
13. The device as recited in claim 10 , wherein the first metal is comprised of a metal selected from the group consisting of Co, Ru, Ir, Rh, W, Mn and Ni.
14. The device as recited in claim 10 , wherein the selected element is selected from the group consisting of C and O.