Polishing slurry and method for chemical-mechanical polishing of copper
The claimed invention involves a novel aqueous polishing slurry for chemical-mechanical polishing that is effective for polishing copper at high polish rates. The aqueous slurry according to the present invention comprises particles of MoO 2 in an oxidizing agent. A method for polishing copper by chemical-mechanical polishing includes contacting copper with a polishing pad and an aqueous slurry comprising particles of MoO 2 in an oxidizing agent.
1 . An aqueous polishing slurry for chemical-mechanical polishing, comprising particles of MoO 2 and an oxidizing agent.
2 . The aqueous polishing slurry of claim 1 , wherein said polishing slurry comprises about 0.5% to about 10% by weight particles of MoO 2 .
3 . The aqueous polishing slurry of claim 1 , wherein said polishing slurry comprises about 1% to about 3% by weight particles of MoO 2 .
4 . The aqueous polishing slurry of claim 1 , wherein said polishing slurry comprises about 3% by weight particles of MoO 2 .
5 . The aqueous polishing slurry of claim 1 , wherein the particles of MoO 2 have a mean particle size in the range of about 25 nanometers to about 1 micron.
6 . The aqueous polishing slurry of claim 1 , wherein the particles of MoO 2 have a mean particle size in the range of about 25 nanometers to about 560 nanometers.
7 . The aqueous polishing slurry of claim 1 , wherein the particles of MoO 2 have a mean particle size in the range of about 50 nanometers to about 200 nanometers.
8 . The aqueous polishing slurry of claim 1 , wherein said oxidizing agent comprises one or more selected from the group consisting of ferric nitrate, nitric acid, potassium iodide, and potassium iodate.
9 . The aqueous polishing slurry of claim 1 , wherein said oxidizing agent comprises one or more selected from the group consisting of hydroxylamine hydrochloride and potassium permanganate.
10 . The aqueous polishing slurry of claim 1 , wherein said oxidizing agent is potassium iodate.
11 . The aqueous polishing slurry of claim 1 , further comprising an acid or a base for adjusting the pH of said polishing slurry within the range of from about 1 to about 14.
12 . The aqueous polishing slurry of claim 1 , further comprising an acid or a base for adjusting the pH of said polishing slurry within the range of from about 3 to about 7.
13 . The aqueous polishing slurry of claim 1 , further comprising an acid or a base for adjusting the pH of said polishing slurry to about 4.
14 . The aqueous polishing slurry of claim 1 , wherein said polishing slurry further comprises an anionic surfactant.
15 . The aqueous polishing slurry of claim 14 , wherein said anionic surfactant comprises one or more selected from the group consisting of polyacrylic acid, a carbolic acid or its salt, a sulfuric ester or its salt, a sulfonic acid or its salt, a phosphoric acid or its salt, and a sulfosuccinic acid or its salt.
16 . The aqueous polishing slurry of claim 14 , wherein said anionic surfactant is polyacrylic acid.
17 . The aqueous polishing slurry of claim 1 , wherein said polishing slurry further comprises a cationic surfactant.
18 . The aqueous polishing slurry of claim 17 , wherein said cationic surfactant comprises one or more selected from the group consisting of a primary amine or its salt, a secondary amine or its salt, a tertiary amine or its salt, and a quaternary amine or its salt.
19 . The aqueous polishing slurry of claim 17 , wherein said cationic surfactant is cetyl pyridinium chloride.
20 . The aqueous polishing slurry of claim 1 , further comprising a copper passivating agent.
21 . The aqueous polishing slurry of claim 20 , wherein said copper passivating agent comprises a heterocyclic organic compound.
22 . The aqueous polishing slurry of claim 20 , wherein the copper passivating agent comprises one or more selected from the group consisting of benzotriazole, triazole, and benzimidazole.
23 . The aqueous polishing slurry of claim 1 further comprising supplemental metal oxide particles.
24 . The aqueous polishing slurry of claim 23 , wherein said supplemental metal oxide particles comprise one or more selected from the group consisting of silica, ceria, aluminia, zirconia, titania, magnesia, iron oxide, tin oxide, and germania.
25 . The aqueous polishing slurry of claim 1 , wherein said polishing slurry further comprises molybdenum sulfide particles.
26 . The aqueous polishing slurry of claim 1 , wherein said polishing slurry further comprises about 0.1% to about 10% by weight molybdenum sulfide particles.
27 . The aqueous polishing slurry of claim 1 , wherein said polishing slurry further comprises about 0.5% to about 5% by weight molybdenum sulfide particles.
28 . The aqueous polishing slurry of claim 1 , wherein said polishing slurry further comprises about 1% by weight molybdenum sulfide particles.
29 . The aqueous polishing slurry of claim 1 , wherein said slurry further comprises ethylene diamine tetra acetic acid.
30 . A method for producing MoO 2 , comprising:
providing a supply of MoO 3 ;
heating said supply of MoO 3 in a reducing atmosphere to a temperature in the range of about 400° C. to about 700° C. for a time in the range of about 30 minutes to about 180 minutes.
31 . The method of claim 30 , wherein said reducing atmosphere comprises hydrogen.
32 . A method for polishing copper by chemical-mechanical polishing comprising polishing copper using a polishing pad and an aqueous slurry comprising MoO 2 and an oxidizing agent.
33 . The method of claim 32 , wherein said slurry comprises about 0.5% to about 10% by weight particles of MoO 2 .
34 . The method of claim 32 , wherein said slurry comprises about 1% to about 3% by weight particles of MoO 2 .
35 . The method of claim 32 , wherein said slurry comprises about 3% by weight particles of MoO 2 .
36 . The method of claim 32 , wherein the particles of MoO 2 have a mean particle size in the range of about 25 nanometers to about 1 micron.
37 . The method of claim 32 , wherein the particles of MoO 2 have a mean particle size in the range of about 25 nanometers to about 560 nanometers.
38 . The method of claim 32 , wherein the particles of MoO 2 have a mean particle size in the range of about 50 nanometers to about 200 nanometers.
39 . The method of claim 32 , wherein said oxidizing agent comprises one or more selected from the group consisting of ferric nitrate, nitric acid, potassium iodide, and potassium iodate.
40 . The method of claim 32 , wherein said oxidizing agent comprises one or more selected from the group consisting of hydroxylamine hydrochloride and potassium permanganate.
41 . The method of claim 32 , wherein said oxidizing agent is potassium iodate.
42 . The method of claim 32 , further comprising an acid or a base for adjusting the pH of said slurry within the range of from about 1 to about 14.
43 . The method of claim 32 , further comprising an acid or a base for adjusting the pH of said slurry within the range of from about 3 to about 7.
44 . The method of claim 32 , further comprising an acid or a base for adjusting the pH of said slurry to about 4.
45 . The method of claim 32 , wherein said slurry further comprises an anionic surfactant.
46 . The method of claim 45 , wherein said anionic surfactant comprises one or more selected from the group consisting of polyacrylic acid, a carbolic acid or its salt, a sulfuric ester or its salt, a sulfonic acid or its salt, a phosphoric acid or its salt, and a sulfosuccinic acid or its salt.
47 . The method of claim 45 , wherein said anionic surfactant is polyacrylic acid.
48 . The method of claim 32 , wherein said polishing slurry further comprises a cationic surfactant.
49 . The method of claim 48 , wherein said cationic surfactant comprises one or more selected from the group consisting of a primary amine or its salt, a secondary amine or its salt, a tertiary amine or its salt, and a quaternary amine or its salt.
50 . The method of claim 48 , wherein said cationic surfactant is cetyl pyridinium chloride.
51 . The method of claim 32 , further comprising a copper passivating agent.
52 . The method of claim 51 , wherein said copper passivating agent comprises a heterocyclic organic compound.
53 . The method of claim 51 , wherein the copper passivating agent comprises one or more selected from the group consisting of benzotriazole, triazole, and benzimidazole.
54 . The method of claim 32 further comprising supplemental metal oxide particles.
55 . The aqueous polishing slurry of claim 54 , wherein said supplemental metal oxide particles comprise one or more selected from the group consisting of silica, ceria, aluminia, zirconia, titania, magnesia, iron oxide, tin oxide, and germania.
56 . The method of claim 32 , wherein said slurry further comprises molybdenum sulfide particles.
57 . The method of claim 32 , wherein said slurry further comprises about 0.1% to about 10% by weight molybdenum sulfide particles.
58 . The method of claim 32 , wherein said slurry further comprises about 0.5% to about 5% by weight molybdenum sulfide particles.
59 . The method of claim 32 , wherein said slurry further comprises about 1% by weight molybdenum sulfide particles.
60 . The method of claim 32 , further comprising additionally polishing the copper with a dilute suspension of H 2 O 2 , glycine, BTA, and colloidal silica in de-ionized water at a pH of 4.