Multi-component barrier polishing solution
View Patent ↗The polishing solution is useful for removing barrier materials in the presence of at least one nonferrous interconnect metal with limited erosion of dielectrics. The solution contains 0 to 20 weight percent oxidizer, at least 0.001 weight percent inhibitor for reducing removal rate of the nonferrous interconnect metals, 1 ppm to 4 weight percent organic-containing ammonium cationic salt formed with a quanternary ammonium structure, 1 ppm to 4 weight percent anionic surfactant, the anionic surfactant having 4 to 25 carbon atoms and the total carbon atoms in of the ammonium cationic salt plus the anionic surfactant being 6 to 40 carbon atoms, 0 to 50 weight percent abrasive and balance water; and the solution having a pH of less than 7.
1. A polishing solution useful for removing barrier materials in the presence of at least one nonferrous interconnect metal with limited erosion of dielectrics comprising: 0 to 20 weight percent oxidizer, at least 0.001 weight percent inhibitor for reducing removal rate of the nonferrous interconnect metals, 1 ppm to 4 weight percent organic-containing ammonium cationic salt formed with
wherein the ammonium cationic salt is selected from at least one of tetrabutylammonium salts, benzyltributylammonium salts, benzyltrimethylammonium salts, benzyltriethylammonium salts and mixtures thereof, 1 ppm to 4 weight percent anionic surfactant for increasing removal rate of carbon-doped oxide, the anionic surfactant having 4 to 25 carbon atoms and the total carbon atoms of the ammonium cationic salt plus the anionic surfactant being 6 to 40 carbon atoms, 0 to 50 weight percent abrasive and balance water; and the solution having a pH of less than 5 with a tantalum nitride to copper selectivity of at least a 1 to 1 ratio as measured in Angstroms per minute with a polishing pad pressure normal to a wafer less than 15 kPa and with a tantalum nitride to carbon-doped oxide selectivity of a 1 to 2 ratio to a 10 to 1 ratio as measured in Angstroms per minute with the polishing pad pressure normal to the wafer less than 15 kPa.
2. The polishing solution of claim 1 wherein the anionic surfactant includes at least one of selected from sulfonates, sulfates, phosphates and carboxylates.
3. The polishing solution of claim 2 wherein the anionic surfactant is a hydrocarbon or a fluorocarbon.
4. The polishing solution of claim 3 wherein the anionic surfactant is selected from at least one of lauryl sulfosuccinate, capryl sulfonate, decylsulfate, capryl sulfate, and phosphate fluorocarbons.
5. A polishing solution useful for removing barrier materials in the presence of at least one nonferrous interconnect metal with limited erosion of dielectrics comprising: 0.001 to 15 weight percent oxidizer, at least 0.001 weight percent inhibitor for reducing removal rate of the nonferrous interconnect metals, 1 ppm to 4 weight percent organic-containing ammonium cationic salt formed with
wherein the ammonium cationic salt is selected from at least one of tetrabutylammonium salts, benzyltributylammonium salts, benzyltrimethylammonium salts, benzyltriethylammonium salts and mixtures thereof, 1 ppm to 4 weight percent anionic surfactant for increasing removal rate of carbon-doped oxide, the anionic surfactant having 5 to 20 carbon atoms and the total carbon atoms of the ammonium cationic salt plus the anionic surfactant being 10 to 35, 0 to 50 weight percent abrasive and balance water; and the solution having a pH of less than 5 with a tantalum nitride to copper selectivity of at least a 1 to 1 ratio as measured in Angstroms per minute with a polishing pad pressure normal to a wafer less than 15 kPa and with a tantalum nitride to carbon-doped oxide selectivity of a 1 to 2 ratio to a 10 to 1 ratio as measured in Angstroms per minute with the polishing pad pressure normal to the wafer less than 15 kPa.
6. The polishing solution of claim 5 wherein the anionic surfactant includes at least one of selected from sulfonates, sulfates, phosphates and carboxylates.
7. The polishing solution of claim 6 wherein the anionic surfactant is a hydrocarbon or a fluorocarbon.
8. The polishing solution of claim 7 wherein the anionic surfactant is selected from at least one of lauryl sulfosuccinate, capryl sulfonate, decylsulfate, capryl sulfate, and phosphate fluorocarbons.
9. The polishing solution of claim 8 wherein the solution contains a complexing agent includes at least one selected from the group comprising acetic acid, alanine, aspartic acid, ethyl acetoacetate, ethylene diamine, trimethylene diamine, ethylenediaminetetraacetic acid (EDTA), citric acid, lactic acid, malic acid, maleic acid, malonic acid, oxalic acid, triethylenetetramine, diethylene triamine, glycine, glycolic acid, glutaric acid, salicylic acid, nitrilotriacetic acid, ethylenediamine, N-hydroxyethylethylenediaminetriacetic acid (HEDTA), hydroxyqunoline, tartaric acid, sodium diethyl dithiocarbamate, succinic acid, sulfosalicylic acid, triglycolic acid thioglycolic acid, 3-hydroxybutyric acid, propionic acid, phthalic acid, isophthalic acid, 3-hydroxy salicylic acid, 3,5-dihydroxy salicylic acid, gallic acid, gluconic acid, pyrocatechol, pyrogallol, gallic acid, tannic acid, salts thereof and mixtures thereof.
10. The polishing solution of claim 1 wherein the ammonium cationic salt is a tetrabutylammonium salt.
11. The polishing solution of claim 5 wherein the ammonium cationic salt is a tetrabutylammonium salt.