METHOD TO ELECTRODEPOSIT METALS USING IONIC LIQUIDS

摘要

The present invention relates to a method to electroplate or electropolish a metal on a substrate wherein an ionic liquid selected from the group of N⁺R₁R₂R₃R₄ X^- or N⁺R₅R₆R₇R₈ Y^- is employed as electrolyte, and a metal salt added to the ionic liquid is employed as the metal source or a metal anode is used as the metal source, wherein any one of R₁ to R₈ independently represents a hydrogen, alkyl, cycloalkyl, aryl, or aralkyl group that may be substituted with a group selected from OH, Cl, Br, F, I, phenyl, NH₂, CN, NO₂, COOR₉, CHO, COR₉, or OR₉, at least one of R₅ to R₈ is a fatty alkyl chain, and one or more of R₅ to R₈ can be a (poly)oxyalkylene group wherein the alkylene is a C₁ to C₄ alkylene and the total number of oxyalkylene units can be from 1 to 50 oxyalkylene units, and at least one of R₁ to R₈ is a C₁ to C₄ alkyl chain, R₉ is an alkyl or cycloalkyl group, X- is an anion having an N-acyl sulphonylimide anion (-CO-N^--SO₂-) functionality, Y^- is an anion compatible with the N⁺R₅R₆R₇R₈ ammonium cation, such as a halogenide anion, a carboxylate anion, a sulphate (both organic and inorganic sulphate), sulphonate, carbonate, nitrate, nitrite, thiocyanate, hydroxide, or sulphonylimide anion.