CMP of noble metals
View Patent ↗The invention provides a method of polishing a substrate comprising (i) contacting a substrate comprising a noble metal layer with a chemical-mechanical polishing system comprising (a) a polishing component, (b) an oxidizing agent, and (c) a liquid carrier, and (ii) abrading at least a portion of the noble metal layer to polish the substrate. The polishing component is selected from the group consisting of an abrasive, a polishing pad, or a combination thereof, and the oxidizing agent is selected from the group consisting of bromates, bromites, hypobromites, chlorates, chlorites, hypochlorites, perchlorates, iodates, hypoiodites, periodates, peroxyacetic acid, organo-halo-oxy compounds, salts thereof, and combinations thereof. The chemical-mechanical polishing system has a pH of about 9 or less, and the oxidizing agent does not produce a substantial amount of elemental halogen. The invention also provides a method of polishing a substrate comprising a noble metal layer and a second layer using the aforementioned polishing system that further comprises a stopping compound.
1. A method of polishing a substrate comprising:
(i) contacting a substrate comprising a noble metal layer and a second layer with a chemical-mechanical polishing system comprising:
(a) a polishing component selected from the group consisting of an abrasive, a polishing pad, or a combination thereof,
(b) an oxidizing agent selected from the group consisting of bromates, bromites, hypobromites, chlorates, chlorites, hypochlorites, iodates, hypoiodites, organo-halo-oxy compounds, salts thereof, and combinations thereof,
(c) a stopping compound which suppresses the removal rate of the second layer, wherein the stopping compound is a cationically charged nitrogen-containing compound selected from the group consisting of amines, imines, amides, imides, polymers thereof, and mixtures thereof, and
(d) a liquid carrier, wherein the chemical-mechanical polishing system has a pH of about 9 or less, and wherein the oxidizing agent does not produce a substantial amount of elemental halogen, and
(ii) abrading at least a portion of the noble metal layer to polish the substrate.
2. The method of claim 1 , wherein the organo-halo-oxy compound is selected from the group consisting of N-chlorosuccinimide, N-bromosuccinimide, N-bromoacetamide, N-bromobenzophenoneimine, iodine triacetate, iodine tris(trifluoroacetate), iodobenzene diacetate, pentrafluoroiodobenzene bis(trifluoroacetate), iodosobenzene, iodoxybenzene, iodoxybenzoic acid, salts thereof, and combinations thereof.
3. The method of claim 1 , wherein the chemical-mechanical polishing system has a pH of about 7 or less.
4. The method of claim 3 , wherein the chemical-mechanical polishing system has a pH of about 4 or less.
5. The method of claim 4 , wherein the chemical-mechanical polishing system has a pH of about 1 to about 4.
6. The method of claim 1 , wherein the metal layer comprises a noble metal selected from the group consisting of platinum, iridium, rhenium, ruthenium, rhodium, palladium, silver, osmium, gold, nitrides thereof, oxides thereof, and alloys thereof.
7. The method of claim 6 , wherein the metal layer comprises ruthenium.
8. The method of claim 7 , wherein the chemical-mechanical polishing system comprises about 0.1 wt. % to about 5 wt. % oxidizing agent based on the weight of the liquid carrier and any components dissolved or suspended therein.
9. The method of claim 8 , wherein the oxidizing agent is a bromate or an iodate.
10. The method of claim 9 , wherein the chemical-mechanical polishing system comprises an abrasive suspended in the liquid carrier and the abrasive is a metal oxide abrasive selected from the group consisting of alumina, silica, ceria, zirconia, titania, germania, and combinations thereof.
11. The method of claim 10 , wherein the metal oxide abrasive is silica.
12. The method of claim 9 , wherein the chemical-mechanical polishing system comprises an abrasive, and the abrasive is fixed to a polishing pad.
13. The method of claim 6 , wherein the metal layer comprises iridium.
14. The method of claim 13 , wherein the chemical-mechanical polishing system comprises about 0.1 wt. % to about 5 wt. % oxidizing agent based on the weight of the liquid carrier and any components dissolved or suspended therein.
15. The method of claim 1 , wherein the chemical-mechanical polishing system comprises about 0.1 wt. % to about 5 wt. % oxidizing agent based on the weight of the liquid carrier and any components dissolved or suspended therein.
16. The method of claim 1 , wherein the oxidizing agent is a bromate.
17. The method of claim 1 , wherein the oxidizing agent is an iodate.
18. The method of claim 1 , wherein the chemical-mechanical polishing system comprises an abrasive, and the abrasive is suspended in the liquid carrier.
19. The method of claim 18 , wherein the liquid carrier comprises water.
20. The method of claim 18 , wherein the abrasive is a metal oxide abrasive selected from the group consisting of alumina, silica, ceria, zirconia, titania, germania, and combinations thereof.
21. The method of claim 20 , wherein the metal oxide abrasive is silica.
22. The method of claim 1 , wherein the liquid carrier comprises water.
23. The method of claim 1 , wherein the chemical-mechanical polishing system comprises an abrasive, and the abrasive is fixed to a polishing pad.
24. The method of claim 1 , wherein the chemical-mechanical polishing system further comprises a component selected from the group consisting of a complexing agent, a pH buffering agent, a surfactant, and combinations thereof.
25. The method of claim 1 , wherein the stopping compound is selected from the group consisting of a polyetheramine, N-4-amino(N,N′-bis-[3-aminopropyl]ethylenediamine), 4,7,10-trioxatridecane-1,13-diamine, 3,3-dimethyl-4,4-diaminodicyclohexylmethane, 2-phenylethylamine, N,N-dimethyldipropylenetriamine, 3-(2-methoxyethoxy)propylamine, isophoronediamine, hexamethylenediamine, cyclohexyl-1,3-propanediamine, thiomicamine, (aminopropyl)-1,3-propanediamine, tetraethylenepentamine, tetramethylbutanediamine, propylamine, diaminopropanol, aminobutanol, (2-aminoethoxy)ethanol, and mixtures thereof.
26. The method of claim 1 , wherein the stopping compound is an amine-containing polymer.
27. The method of claim 26 , wherein the amine-containing polymer has 5 or more sequential atoms separating the nitrogen atoms of the amino functional groups.
28. The method of claim 26 , wherein the stopping compound is an amine-containing polymer selected from the group consisting of condensation polymers comprising repeating units tat contain an amino functional group, polydiallyldimethylammonium chloride, and a copolymer comprising repeating units containing one or more amine functional groups and repeating units selected from the group consisting of amides, vinyl acetate, vinyl alcohol, ethylene oxide, and propylene oxide.
29. The method of claim 26 , wherein the amine-containing polymer is an amine-containing block copolymer with at least one polymer block comprising one or more amine functional groups and at least one polymer block not comprising any amine functional groups.
30. A method of polishing a substrate comprising:
(i) contacting a substrate comprising a noble metal layer and a second layer with a chemical-mechanical polishing system comprising:
(a) a polishing component selected from the group consisting of an abrasive, a polishing pad, or a combination thereof,
(b) an oxidizing agent selected from the group consisting of perchlorates, periodates, peroxyacetic acid, salts thereof, and combinations thereof,
(c) an amine-containing polymer having 5 or more sequential atoms separating the nitrogen atoms of the amino functional groups, and
(d) a liquid carrier,
wherein the chemical-mechanical polishing system has a pH of about 9 or less, and wherein the oxidizing agent does not produce a substantial amount of elemental halogen, and
(ii) abrading at least a portion of the noble metal layer to polish the substrate.
31. The method of claim 30 , wherein the amine-containing polymer is selected from the group consisting of condensation polymers comprising repeating units that contain an amino functional group, polydiallyldimethylammonium chloride, and a copolymer comprising repeating units containing one or more amine functional groups and repeating units selected from the group consisting of amides, vinyl acetate, vinyl alcohol, ethylene oxide, and propylene oxide.
32. The method of claim 30 , wherein the amine-containing polymer is a block copolymer with at least one polymer block comprising one or more amine functional groups and at least one polymer block not comprising any amine functional groups.