Polishing method, metallization fabrication method, method for manufacturing semiconductor device and semiconductor device
View Patent ↗Described is a polishing technique adapted for multilevel metallization of an electronic circuit device, which comprises polishing a metal film with a polishing liquid containing an oxidizing substance, a phosphoric acid and a protection-layer forming agent. The present invention makes it possible to polishing a metal film at a high removal rate while suppressing occurrence of scratches, delamination, dishing or erosion.
1. A polishing method for a copper film by chemical mechanical polishing, comprising forming a protection-layer on the copper film with a forming agent, polishing the protection-layer away on a convex portion of the copper film, oxidizing a surface of the convex portion of the copper film by an oxidizing substance and rendering an oxidized substance water soluble by phosphoric acid, wherein a polishing liquid used in said polishing contains an oxidizing substance, a phosphoric acid and a protection-layer forming agent and methyl alcohol.
2. A polishing method according to claim 1 , wherein said oxidizing substance contains hydrogen peroxide, and said phosphoric acid contains one selected from the group of orthophosphoric acid and phosphorous acid.
3. A polishing method according to claim 2 , wherein said protection-layer forming agent contains benzotriazole.
4. A polishing method according to claim 2 , wherein said protection-layer forming agent contains a carboxyl-containing polymer.
5. A polishing method according to claim 2 , wherein said polishing slurry contains abrasives not more than 1 wt %.
6. A polishing method for removing a copper film over an insulating film by chemical mechanical polishing, comprising forming a protection-layer with benzotriazole and, polishing the protection-layer away on a convex portion of the copper film, oxidizing a surface of the convex portion of the copper film by an oxidizing substance and rendering an oxidized copper film water soluble by a phosphoric acid, wherein a polishing liquid used in said polishing contains an oxidizing substance, a phosphoric acid, malonic acid, a benzotriazole and methyl alcohol.
7. A polishing method according to claim 6 , wherein said oxidizing substance contains hydrogen peroxide, said phosphoric acid contains one selected from the group of orthophosphoric acid and phosphorous acid.
8. A polishing method according to claim 6 , wherein said polishing slurry contains abrasives not more than 1 wt %.
9. A polishing method according to claim 8 , wherein said oxidizing substance contains hydrogen peroxide, said phosphoric acid contains one selected from the group of orthophosphoric acid and phosphorous acid, and said protection-layer forming agent contains benzotriazole.
10. A polishing method according to claim 8 , wherein said oxidizing substance contains hydrogen peroxide, said phosphoric acid contains one selected from the group of orthophosphoric acid and phosphorous acid, and said protection-layer forming agent contains a carboxyl-containing polymer.
11. A polishing method according to claim 8 , wherein said oxidizing substance contains hydrogen peroxide, said phosphoric acid contains one selected from the group of orthophosphoric acid and phosphorous acid, and said protection-layer forming agent contains one selected from the group of polyacrylic acid, polyammonium acrylate polyamine acrylate, and a bridged polymer thereof.
12. A polishing method according to claim 8 , wherein said polishing slurry for first metal film contains abrasives not more than 1 wt %.
13. A polishing method comprising the steps of:
(a) depositing a first metal film of a barrier metal on an insulating film having convex and concave portions and depositing a second metal film of copper on the first metal film;
(b) removing the second metal film on the convex portion and leaving the second metal film in the concave portion on the first metal by chemical mechanical polishing comprising forming a protection-layer with a forming agent on a surface of the second metal film, polishing the protection-layer away on a convex portion of the surface, oxidizing a surface of a convex portion of the second metal film by an oxidizing substance and rendering the oxidized metal water soluble by a phosphoric acid, wherein a polishing liquid used in said polishing contains an oxidizing substance, a phosphoric acid and a protection-layer forming agent and methyl alcohol;
(c) removing the first metal film on the convex portion and leaving the first metal in the concave portion by chemical mechanical polishing by a polishing liquid containing an oxidizing substance, a phosphoric acid, a protection-layer forming agent comprised of an anticorrosive.
14. A polishing method comprising the steps of:
(a) depositing a first metal film of a barrier metal on an insulating film having convex and concave portions and depositing a second metal film of copper on the first metal film;
(b) removing the second metal film on the convex portion and leaving the second metal film in the concave portion on the first metal by chemical mechanical polishing comprising forming a protection-layer with a forming agent on a surface of the second metal film, polishing the protection-layer away on a convex portion of the surface, oxidizing a surface of a convex portion of the second metal film by an oxidizing substance and rendering the oxidized metal water soluble by a phosphoric acid, wherein a polishing liquid used in said polishing contains oxidizing substance, a phosphoric acid, malonic acid, a protection-layer forming agent and methyl alcohol;
(c) removing the first metal film on the convex portion and leaving the first metal in the concave portion by chemical mechanical polishing by a polishing liquid containing an oxidizing substance, a phosphoric acid, a protection-layer forming agent comprised of an anticorrosive.
15. A polishing method according to claim 14 , wherein said oxidizing substance contains hydrogen peroxide, said phosphoric acid contains one selected from the group of orthophosphoric acid and phosphorous acid, and said protection-layer forming agent contains benzotriazole.
16. A polishing method according to claim 14 , wherein said oxidizing substance contains hydrogen peroxide, said phosphoric acid contains one selected from the group of orthophosphoric acid and phosphorous acid, and said protection-layer forming agent contains a carboxyl-containing polymer.
17. A polishing method according to claim 14 , wherein said oxidizing substance contains hydrogen peroxide, said phosphoric acid contains one selected from the group of orthophosphoric acid and phosphorous acid, and said protection-layer forming agent contains one selected from the group of polyacrylic acid, polyammonium acrylate polyamine acrylate, and a bridged polymer thereof.
18. A polishing method according to claim 14 , wherein said polishing slurry for first metal film contains abrasives not more than 1 wt %.