Selective barrier slurry for chemical mechanical polishing
View Patent ↗The polishing solution is useful for removing a barrier from a semiconductor substrate. The solution contains by weight percent 0.001 to 25 oxidizer, 0.0001 to 5 anionic surfactant, 0 to 15 inhibitor for a nonferrous metal, 0 to 40 abrasive, 0 to 20 complexing agent for the nonferrous metal, 0.01 to 12 barrier removal agent selected from imine derivative compounds, hydrazine derivative compounds and mixtures thereof, and water; and the solution has an acidic pH.
1. A solution useful for removing a barrier from a semiconductor substrate, the semiconductor substrate containing tantalum nitride (TaN), copper and carbon-doped oxide (CDO), comprising by weight percent 0.001 to 25 oxidizer, 0.02 to 0.35 anionic surfactant, 0 to 15 inhibitor for a nonferrous metal, 0 to 40 abrasive, 0 to 20 complexing agent for the nonferrous metal, 0.01 to 12 barrier removal agent selected from formamidine, formamidine salts, formamidine derivatives, guanidine, guanidine derivatives, guanidine salts and mixtures thereof; and water; and the solution has an acidic pH and provides a TaN/CDO selectivity of at least 2 to 1 as measured with a microporous polyurethane polishing pad pressure measured normal to a wafer of less than 13.8 kPa.
2. The solution of claim 1 wherein the anionic surfactant contains a chemical group selected from at least one of carboxylate, sulfonate, sulfate and phosphate.
3. The solution of claim 1 wherein the anionic surfactant is selected from at least one of alkyl glutamates, dodecylbenzenesulfonate, alkyl α-olefin sulfonates, dialkyl sulfosuccinates, alkylsulfonates, alkyl amphohydroxylypropyl sulfonates, alkylhydroxyethylimidazolines, alkyl amidopropyl betaines, methyl alkyltaurate, alkyl imidazoline and mixtures thereof.
4. The polishing solution of claim 1 wherein the polishing solution is abrasive-free.
5. A solution useful for removing a barrier from a semiconductor substrate, the semiconductor substrate coutainin tantalum nitride (TaN) and carbon-doped (CDO), comprising by weight percent 0.01 to 20 oxidizer, 0.02 to 0.35 anionic surfactant, 0.001 to 15 inhibitor for a nonferrous metal, 0 to 25 abrasive, 0 to 10 complexing agent for the nonferrous metal, 0.1 to 10 barrier removal agent selected from formamidine, formamidine salts, formamidine derivatives, guanidine, guanidine derivatives, guanidine salts and mixtures thereof; and water; and the solution has an acidic pH of greater than 2 and provides a TaN/CDO selectivity of at least 2 to 1 as measured with a microporous polyurethane polishing pad pressure measured normal to a wafer of less than 13.8 kPa.
6. The solution of claim 5 wherein the anionic surfactant contains a chemical group selected from at least one of carboxylate, sulfonate, sulfate and phosphate.
7. The solution of claim 5 wherein the anionic surfactant is selected from at least one of alkyl glutamates, dodecylbenzenesulfonate, alkyl α-olefin sulfonates, dialkyl sulfosuccinates, alkylsulfonates, alkyl amphohydroxylypropyl sulfonates, alkylhydroxyethylimidazolines, alkyl amidopropyl betaines, methyl alkyltaurate, alkyl imidazoline and mixtures thereof.
8. The solution of claim 5 wherein the anionic surfactant is selected from at least one of methyl cocoyltaurate, dicyclohexyl sulfosuccinate (1,4-dicyclohexyl sulfonatosuccinate), dinonyl sulfosuccinate, cocoamphohydroxypropylsulfonate, C14-17 alkyl sec sulfonate, isostearylhydroxyethylimidazoline, cocamidopropyl betaine imidazoline C8/C10, C14-16 olefin sulfonate (dodecylbenzenesulfonate), hydrogenated tallow glutamate, POE (4) oleyl ether phosphate, lauryl, sulfosuccinate, dodecylbenzenesulfonate and mixtures thereof.
9. The polishing solution of claim 5 wherein the polishing solution is abrasive-free.