Metal line in semiconductor device and method for forming the same
View Patent ↗A metal line in a semiconductor device includes an insulation layer having trenches formed therein, a barrier metal layer formed over the insulation layer and the trenches, a metal layer formed over the barrier metal layer, wherein the metal layer fills the trenches, and an anti-galvanic corrosion layer formed on an interface between the metal layer and the barrier metal layer.
1. A method for forming a metal line in a semiconductor device, the method comprising:
providing a substrate including an insulation layer having a plurality of trenches formed therein;
forming a barrier metal layer over the insulation layer and the trenches;
forming a first metal layer over the barrier metal layer;
forming a second metal layer over the first metal layer, wherein the second metal layer fills the trenches; and
forming an anti-galvanic corrosion layer on an interface between the barrier metal layer and the second metal layer using a thermal process.
2. The method of claim 1 , wherein the anti-galvanic corrosion layer comprises an alloy layer including combined materials of the first and second metal layers.
3. The method of claim 1 , wherein the first metal layer comprises a first metal and the second metal layer comprises a second metal, the first metal and the second metal having opposite polarities.
4. The method of claim 1 , wherein the first metal layer comprises copper (Cu) and the second metal layer comprises aluminum (Al).
5. The method of claim 1 , wherein the barrier metal layer comprises a stack structure comprising a material selected from a group consisting of titanium (Ti)/titanium nitride (TiN), Ti/TiN/Ti, tantalum (Ta)/tantalum nitride (TaN), Ta/TaN/Ta, Ti/titanium silicon nitride (TiSiN), and Ti/TiSiN/Ti.
6. The method of claim 1 , further comprising, after forming the anti-galvanic corrosion layer:
performing a chemical mechanical polishing (CMP) process on the second metal layer to isolate adjacent portions of the second metal layer; and
performing a cleaning process.
7. The method of claim 6 , wherein performing the CMP process comprises oxidizing the second metal layer and removing portions of the oxidized second metal layer formed over the insulation layer using a polish slurry having a pH ranging from approximately 4 to approximately 6.
8. The method of claim 7 , wherein the CMP process comprises adding an oxidizer of approximately 2 wt % to approximately 6 wt % to oxidize the second metal layer, the polish slurry comprising colloidal silica or aluminum oxide-based polish particles.
9. The method of claim 6 , wherein performing the cleaning process comprises adding one selected from a group consisting of a metal corrosion inhibitor, an amine-based hydrazine, and hydrogen fluoride (HF), to a deionized water cleaning solution such that the cleaning solution is a basic solution.
10. The method of claim 9 , wherein the metal corrosion inhibitor comprises methyl gallate.
11. A method for forming a metal line in a semiconductor device, the method comprising:
providing a substrate including an insulation layer having a plurality of trenches formed therein;
forming a barrier metal layer over the insulation layer and the trenches; and
forming a metal layer including a first metal over the barrier metal layer, the metal layer filling the trenches,
wherein a gas including a second metal is supplied when forming the metal layer to form an anti-galvanic corrosion layer on an interface between the barrier metal layer and the metal layer.
12. The method of claim 11 , wherein the anti-galvanic corrosion layer comprises an alloy layer including a combination of the first and second metals.
13. The method of claim 11 , wherein the first metal and the second metal have opposite polarities.
14. The method of claim 11 , wherein the first metal comprises aluminum (Al) and the second metal comprises copper (Cu).
15. The method of claim 11 , wherein the barrier metal layer comprises a stack structure comprising a material selected from a group consisting of titanium (Ti)/titanium nitride (TiN), Ti/TiN/Ti, tantalum (Ta)/tantalum nitride (TaN), Ta/TaN/Ta, Ti/titanium silicon nitride (TiSiN), and Ti/TiSiN/Ti.
16. The method of claim 11 , further comprising, after forming the metal layer:
performing a chemical mechanical polishing (CMP) process on the metal layer to isolate adjacent portions of the metal layer; and
performing a cleaning process.
17. The method of claim 16 , wherein performing the CMP process comprises oxidizing the metal layer and removing portions of the oxidized metal layer formed over the insulation layer using a polish slurry having a pH ranging from approximately 4 to approximately 6.
18. The method of claim 17 , wherein the CMP process comprises adding an oxidizer of approximately 2 wt % to approximately 6 wt % to oxidize the metal layer, the polish slurry comprising colloidal silica or aluminum oxide-based polish particles.
19. The method of claim 16 , wherein performing the cleaning process comprises adding one selected from a group consisting of a metal corrosion inhibitor, an amine-based hydrazine, and hydrogen fluoride (HF), to a deionized water cleaning solution such that the cleaning solution is a basic solution.
20. The method of claim 19 , wherein the metal corrosion inhibitor comprises methyl gallate.