Composition for tin or tin alloy electroplating comprising leveling agent
AssigneeBASF SE
InventorsAlexander Fluegel, Jean-Pierre Berkan Lindner, Marco Arnold
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Abstract
The present invention relates to the use of an aqueous composition comprising tin ions optionally further alloy metal ions selected from silver, copper, indium, and bismuth ions and at least one additive comprising a linear or branched polyimidazolium compound comprising the structural unit of formula (L1) for depositing tin or tin alloy containing layers and a process for depositing tin alloy layer onto a substrate.
Claims14
An aqueous composition, comprising:
- tin ions;
- at least one alloy metal ion selected from the group consisting of silver, indium, and bismuth ions;
- and
- at least one additive comprising a linear or branched polyimidazolium compound comprising a structural unit of formula (L1):
- wherein:
- R1, R2, R3 are each independently selected from the group consisting of an H atom and an organic radical having from 1 to 20 carbon atoms;
- X1 is
- a group —Y2—Y1—Y2—,
- with the proviso that X1 does not comprise a hydroxyl group in the α or β positions relative to the nitrogen atoms of the imidazole rings;
- Y1 is selected from the group consisting of phenyl, naphtyl, pyridyl, pyrimidyl, and furanyl;
- Y2 is independently selected from methanediyl, ethanediyl, 1,3-propanediyl and 1,4-butanediyl;
- and
- n is an integer from 5 to 5000.
A bath for depositing at least one tin alloy containing layer, the bath comprising an additive including a linear or branched polyimidazolium compound comprising a structural unit of formula (L1):
- wherein:
- the at least one tin alloy containing layer comprises an alloy metal selected from the group consisting of silver, copper, indium, and bismuth in an amount of 0.01 to 10% by weight;
- R1, R2, R3 are each independently selected from the group consisting of an H atom and an organic radical having from 1 to 20 carbon atoms,
- X1 is
- a group —Y2—Y1—Y2—,
- with the proviso that X1 does not comprise a hydroxyl group in the α or β positions relative to the nitrogen atoms of the imidazole rings;
- Y1 is selected from the group consisting of phenyl, naphtyl, pyridyl, pyrimidyl, and furanyl;
- Y2 is independently selected from methanediyl, ethanediyl, 1,3-propanediyl and 1,4-butanediyl;
- and
- n is an integer from 5 to 5000.
A process for depositing a tin alloy layer on a substrate, the process comprising:
- a) contacting a tin alloy electroplating bath with a substrate, the tin alloy electroplating bath comprising a composition comprising:
- tin ions;
- at least one alloy metal ion selected from the group consisting of silver, copper, indium, and bismuth ions;
- and
- at least one additive comprising a linear or branched polyimidazolium compound comprising a structural unit of formula (L1):
- wherein:
- R1, R2, R3 are each independently selected from the group consisting of an H atom and an organic radical having from 1 to 20 carbon atoms;
- X1 is
- a group —Y2—Y1—Y2—,
- with the proviso that X1 does not comprise a hydroxyl group in the α or β positions relative to the nitrogen atoms of the imidazole rings,
- Y1 is selected from the group consisting of phenyl, naphtyl, pyridyl, pyrimidyl, and furanyl;
- Y2 is independently selected from methanediyl, ethanediyl, 1,3-propanediyl and 1,4-butanediyl;
- and
- n is an integer from 5 to 5000;
- and
- b) applying a current density to the substrate for a time sufficient to deposit a tin alloy layer onto the substrate, wherein the alloy metal content of the deposited tin alloy layer is from 0.01 to 10% by weight.
Dependencies are inferred from the claim text.