A composition containing a smoothing agent for electroplating tin or tin alloys.

Abstract

The present invention relates to a compound comprising tin ions, optionally alloying metal ions selected from silver ions, indium ions, and bismuth ions, and a compound of formula L1a [Formula 1] TIFF2024500793000027.tif4789 or formula L1b [Case 2] TIFF2024500793000028.tif4680(in the formula, R L1 is each group R L1 n are independently selected from -F, linear or branched C1-C6 alkyl containing one or more F substituents at the C1 or C2 positions; R L2 is C1-C6 alkyl, C1-C6 alkenyl, C5-C 12 Aryl, C6-C 15 Alkylaryl, C6-C 15 arylalkyl, all of which may be substituted by CN, OH, C1-C6 alkoxy or halogen, in particular F; R L3 is selected from H, C1-C6 alkyl, C1-C6 alkenyl, C1-C6 alkoxy, halogen, CN, and OH; R L4 is each R L4 Independently, R L1 and R L3 is selected from R L11 , R L12 , R L13 is R L1 and R L3 are independently selected from R L11 , R L12 , R L13 At least one, preferably two, and most preferably all of L1 This is conditional on the fact that X L1 is (a) a divalent saturated or unsaturated group, such as: (a) a C3-C5 alkanediyl group, (b) a C3-C5 alkenediyl group, is selected from or (c) C5-C with adjacent C=C double bonds 12 Forms an aromatic ring system, and n is a group R selected from 1, 2 or 3 L1 (the number of and at least one additive represented by the formula:

Description

[Technical Field]

[0001] The present invention relates to a tin or tin alloy electroplating composition containing a smoothing agent, the use of the composition, and a method for electroplating tin or tin alloys. [Background technology]

[0002] Metals and metal alloys are commercially important, particularly in the electronics industry, and are often used as electrical contacts, finishes, and solder. Lead-free solders, such as tin, tin-silver, tin-copper, tin-bismuth, and tin-silver-copper, are common metals used in solder. These solders are often deposited onto semiconductor substrates by metal electroplating baths.

[0003] A typical tin plating solution contains dissolved tin ions, water, an acid electrolyte sufficient to impart conductivity to the bath (e.g., methanesulfonic acid), an antioxidant, and proprietary additives to improve the uniformity of the plating and the quality of metal deposition with respect to surface roughness and void formation. Such additives typically include, among others, surfactants and crystallization agents.

[0004] Certain applications of lead-free solder plating present challenges in the electronics industry. For example, when used as a capping layer on copper pillars, relatively small amounts of lead-free solder, such as tin-silver solder, are deposited on top of the copper pillars. When plating such small amounts of solder, it is often difficult to achieve a uniform height of solder composition on top of each pillar, both within the die and across the wafer. Using known solder electroplating baths often results in deposition with a relatively rough surface morphology.

[0005] US3361652 discloses an acidic tin electroplating composition comprising a primary brightener represented by the formula X-CH=CH-Y, where X is phenyl, furfuryl, or pyridyl, and Y may be a hydrogen, formyl, carboxyl, alkyl, hydroxyalkyl, formylalkyl, or carboxylic acid acyl radical. One of the brighteners mentioned is benzylideneacetone (benzalacetone).

[0006] In a preferred embodiment, US4582576 is given by the following formula [ka] Disclosed are acidic tin electroplating compositions comprising a carbonyl compound represented by the formula, where X1 and X2 may be hydrogen, hydroxyl, alkoxy, chlorine, or bromine, and the alkyl group of the alkoxy group may contain about 1 to about 5 carbon atoms. Examples of such compounds include benzylideneacetone (benzalacetone) and 3'-chlorobenzylideneacetone.

[0007] US2014 / 183050A1 discloses a tin or tin alloy electroplating solution suitable for via filling to selectively deposit tin or a tin alloy in vias, and a method for via filling using the solution, which can form substantially void-free columnar deposition. The plating solution contains a specific α,β-unsaturated carbonyl compound added to the tin or tin alloy plating solution. Such carbonyl compounds may be specifically substituted with alkyl groups, alkenyl groups, alkoxy groups, amino groups, halogen atoms, hydroxyl groups, carbonyl groups, and cyano groups, each having 1 to 9 carbon atoms. Examples include 3-chloroacetophenone, crotonyl chloride, butenoyl chloride, and 4-chloro-2-butenal.

[0008] However, prior art has not solved, or even addressed, the problem of achieving uniform height both within the die and across the wafer, and improving the roughness of the deposited solder. Therefore, the electronics industry still needs pure tin or tin alloy electroplating baths that provide improved roughness Ra and good, or even better, uniformity in height, also known as coplanarity (COP), of solder deposition. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] US3361652 [Patent Document 2] US4582576 [Patent Document 3] US2014 / 183050A1 [Overview of the project] [Problems that the invention aims to solve]

[0010] An object of the present invention is to provide a tin or tin alloy electroplating composition that yields a uniform and planar tin or tin alloy deposition, particularly in the form of a characteristic recessed shape with a width of 1 to 200 micrometers. A further object of the present invention is to provide a tin or tin alloy electroplating composition having good leveling properties, in particular a tin or tin alloy electroplating bath that can provide a substantially planar tin or tin alloy layer and fill characteristic shapes on a micrometer scale, without substantially forming defects, such as voids, etc. [Means for solving the problem]

[0011] Summary of the Invention The present invention relates to a tin ion, an alloy metal ion optionally selected from silver ions, indium ions, and bismuth ions, and formula L1a [ka] or the formula L1b

Chemical formula

[0012] A further embodiment of the present invention is a method of using the additives described herein in a bath for precipitating a tin or tin alloy-containing layer, wherein the tin alloy-containing layer contains an alloying metal selected from silver, copper, indium, and bismuth in an amount of 0.01 to 10% by mass.

[0013] A further embodiment of the present invention is a method for depositing a tin or tin alloy layer on a substrate, comprising the following steps a) A step of bringing a tin alloy electroplating bath containing the composition described herein into contact with a substrate, and b) The process of applying an electric current to the substrate for a sufficient time to deposit a tin or tin alloy layer onto the substrate. This is the method.

[0014] The additives according to the present invention can be advantageously used in bonding technologies, for example, in the manufacture of tin or tin alloy bumps for bump processes, typically having a height and width of 1 to 200, preferably 3 to 100, most preferably 5 to 50 micrometers, in circuit board technology, or in electronic circuit packaging processes. In one particular embodiment, the substrate includes a characteristic shape of micrometer size, and deposition is performed to fill the characteristic shape of micrometer size, which has a size of 1 to 200 micrometers, preferably 3 to 100 micrometers.

[0015] The additives according to the present invention result in the deposition of tin or tin alloys, particularly tin-silver, exhibiting better roughness Ra compared to unsubstituted α,β-unsaturated carbonyl compounds or α,β-unsaturated carbonyl compounds having substituents other than the fluorine-containing substituents described herein. The additives according to the present invention also result in the deposition of tin or tin alloys exhibiting good or even better coplanarity (COP). Furthermore, the use of the additives according to the present invention extends the process window of tin or tin alloy electroplating baths. [Modes for carrying out the invention]

[0016] Detailed description of the present invention Additive according to the present invention In the following, the terms "additive," "leveler," "fluorinated α,β-unsaturated carbonyl compound," and "fluorinated compound" are used synonymously.

[0017] In the first embodiment, which comprises an aliphatic or aromatic cyclic fluorinated α,β-unsaturated carbonyl compound, in addition to tin ions and any alloying metal ions selected from silver ions, indium ions, and bismuth ions, the electroplating composition is of formula L1a [ka] (In the formula, R L1 Each base R L1 n Independently, selected from linear or branched C1-C6 alkyl groups containing one or more F substituents at the -F, C1, or C2 position, R L2 C1-C6 alkyl, C1-C6 alkenyl, C5-C 12 Aryl, C6~C 15 Alkylaryl, C6~C 15 These are arylalkyl groups, and they may all be substituted with CN, OH, C1-C6 alkoxy or halogen, especially fluorine. R L3The group is selected from H, C1-C6 alkyl, C1-C6 alkenyl, C1-C6 alkoxy, halogen, CN, and OH. R L4 R L1 or R L3 And, X L1 teeth, (a) Below: (i) C3-C5 alkanes, (ii) C3-C5 Alkenziel, A divalent group selected from, or (b) C5~C together with adjacent C=C double bonds 12 Forming an aromatic ring system, and n is a base R selected from 1, 2, or 3, preferably 1 or 2, most preferably 1. L1 (The number of) It contains at least one additive represented by .

[0018] As used herein, “alkyl” and “alkanediyl” mean linear, branched, or cyclic alkyl or alkanediyl groups, respectively. As used herein, “aromatic” or “aryl” means unsubstituted (substituent R L1(excluding) or a monocyclic or bicyclic carbocyclic aromatic group which may be substituted with one or more Cl, C1-C6 alkyl groups, specifically one or more C1-C4 alkyl groups, more specifically one or more methyl, ethyl or propyl groups, most specifically one or two methyl or ethyl groups. As used herein, "alkenyl" and "alkenediyl" mean a linear, branched or cyclic alkenyl group or alkenediyl group, respectively. As used herein, "arylalkyl" means an alkyl group substituted with one or more aryl groups, specifically one or more phenyl groups, most specifically one phenyl group. As used herein, "alkylaryl" means an aryl group substituted with one or more C1-C6 alkyl groups, specifically one or more C1-C4 alkyl groups, more specifically one or more methyl, ethyl or propyl groups, most specifically one or two methyl or ethyl groups. As used herein, "fluorinated at the C1 or C2 position" means that the alkyl group has at least one, preferably at least two, fluorinated substituents at the C1 or C2 position. Any fluorinated α,β-unsaturated carbonyl compound may have an E or Z configuration, or a mixture thereof, preferably an E configuration.

[0019] Preferably, R L1 -F, -CR L30 2F, -CR L30 F2, -CF3, -CFR L30 -CR L30 3. -CF2-CR L30 3. -CF2-CFR L30 2. -CF2-CF2R L30 , and -CF2-CF3 may be selected, R L30 The group is selected from H and C1-C6 alkyl groups. Particularly preferred group R L1 This may be F or a perfluorinated C1-C4 alkyl group, particularly -CF3. Different groups R L1 is any specific substituent R L1 n , that is, more than one substituent R L1 If R exists, L1 1. R L1 2, and RL1 It can be used for 3.

[0020] Preferably, R L2 The group is selected from methyl, ethyl, 1-propyl, 2-propyl, tert.butyl, and benzylidene, more preferably methyl and ethyl, ethenyl, and benzylidene, all of which may be unsubstituted or substituted with F, CN. The most preferred group is R L2 R may be methyl or ethyl, and these may all be unsubstituted or substituted with F. L2 R L1 It must be emphasized that this is different.

[0021] Preferably, R L3 The element is selected from H, C1-C4 alkyl, C1-C4 alkenyl, C1-C4 alkoxy, Cl, and CN, more preferably selected from H, methyl, or ethyl, and most preferably selected from H.

[0022] Preferably, R L4 R L1 The element is selected from H, C1-C4 alkyl, C1-C4 alkenyl, C1-C4 alkoxy, Cl, and CN, more preferably selected from H, methyl, or ethyl, and most preferably selected from H.

[0023] In the first preferred alternative to the first embodiment, the smoothing agent is of formula L2a [ka] Or formula L2b [ka] (In the formula, R L1a R L1 , Cl, Br, and C1-C6 alkyl, preferably C1-C3 alkyl, where this alkyl may be unsubstituted or substituted with F, CN, Cl, and Br, and m is 0, 1, 2, or 3 or 4, preferably 0, 1, or 2, most preferably 0 or 1. It may be a cyclic aliphatic compound represented by .

[0024] Particularly preferred compounds of the first alternative fluorinated α,β-unsaturated carbonyl compound are 4-(3,6-dimethylcyclohexen-1-yl)buto-3-en-2-one, 4-(3-fluoro-6-methylcyclohexen-1-yl)buto-3-en-2-one, 4-(3,6-difluoro-cyclohexen-1-yl)buto-3-en-2-one, 4-(6-fluoro-3-methylcyclohexen-1-yl)buto-3-en-2-one, 4-[3-methyl-6-(trifluoromethyl)cyclohexen-1-yl]buto-3-en-2-one, 4-[6-(trifluoromethyl)cyclohexen-1-yl]buto-3-en-2-one, 4-[3-(trifluoromethyl)cyclohexen-1-yl] [L]buto-3-en-2-one, 4-[3,6-bis(trifluoromethyl)cyclohexen-1-yl]buto-3-en-2-one, 4-(3-fluorocyclohexen-1-yl)buto-3-en-2-one, 4-(6-fluorocyclohexen-1-yl)buto-3-en-2-one, 4-[3-(1-fluoroethyl)cyclohexen-1-yl]buto-3-en-2-one, 4-[3,6-bis(1-fluoroethyl)cyclohexen-1-yl]buto-3-en-2-one, 4-[3-(2-fluoroethyl)cyclohexen-1-yl]buto-3-en-2-one, and 4-[3,6-bis(2-fluoroethyl)cyclohexen-1-yl]buto-3-en-2-one, and formula L2c [ka] It is a compound represented by [formula].

[0025] In the second preferred alternative to the first embodiment, the smoothing agent is of formula L3 [ka] It may be an aromatic compound represented by .

[0026] A second alternative, particularly preferred smoothing agent, is formula L3a [ka] Or formula L3b [ka] It may be a compound represented by .

[0027] Ortho-substituted phenyl groups may be used even if they are not particularly desirable. Such compounds represented by formulas L3, L3a, and L3b may be further substituted with C1-C4 alkyl, C1-C4 alkoxy, Cl, and CN.

[0028] A second alternative, particularly preferred, fluorinated α,β-unsaturated carbonyl compound is 4-(3-fluorophenyl)-buto-3-en-2-one, 4-[3-(trifluoromethyl)phenyl]-buto-3-en-2-one, 4-(4-fluorophenyl)-buto-3-en-2-one, 4-[4-(trifluoromethyl)phenyl]-buto-3-en-2-one, 4-(3,5-difluorophenyl)-buto-3-en-2-one, 4-(3,5-bis(trifluoromethyl)phenyl)-buto-3-en-2-one, 4-(2,4,6-trifluorophenyl)buto-3-en-2-one, 4-[2,4,6-tris(trifluoromethyl)phenyl]buto-3-en-2-one, 4-[4-(difluoromethyl)phenyl]buto-3-en-2-one, 4-[3-(difluoromethyl)phenyl]buto-3-en-2-one, 4-[3,5-bis(difluoromethyl)phenyl]buto-3-en-2-one, 4-[4-(fluoromethyl)phenyl]buto-3-en-2-one, 4-[3-(fluoromethyl)phenyl]buto-3-en-2-one To-3-en-2-one, 4-[3,5-bis(fluoromethyl)phenyl]buto-3-en-2-one, 4-[4-(1,1,2,2,2-pentafluoroethyl)phenyl]buto-3-en-2-one, 4-[3-(1,1,2,2,2-pentafluoroethyl)phenyl]buto-3-en-2-one, 4-[3,5-bis(1,1,2,2,2-pentafluoroethyl)phenyl]buto-3-en-2-one, 4-[4-(2,2,2-trifluoroethyl)phenyl]buto-3-en-2-one, 4- Selected from [3-(2,2,2-trifluoroethyl)phenyl]buto-3-en-2-one, 4-[3,5-bis(2,2,2-trifluoroethyl)phenyl]buto-3-en-2-one, 4-(2,4-bis(trifluoromethyl)phenyl)buto-3-en-2-one, (4-(4-(trifluoromethyl)phenyl)pento-1-en-3-one, 4-(4-fluorophenyl)pento-1-en-3-one, and 1-(4-fluorophenyl)-4,4-dimethylpento-1-en-3-one.

[0029] Further preferred fluorinated α,β-unsaturated carbonyl compounds include, but are not limited to, compounds containing alkoxy or hydroxy substitutions, such as 1-(2-fluoro-5-methoxyphenyl)-4,4-dimethylpento-1-en-3-one, 1-(2-fluoro-5-methoxyphenyl)-4-methylpento-1-en-3-one, 4-(4-fluoro-3-methoxyphenyl)buto-3-en-2-one, 4-(3-fluoro-4-methoxyphenyl)buto-3-en-2-one, 1-(2-fluoro-5-methoxyphenyl)pento-1-en-3-one, and 4-(2-fluoro-4-methylpento-1-en-3-one). These are toxyphenyl)buto-3-en-2-one, 4-(5-fluoro-2-methoxyphenyl)buto-3-en-2-one, 4-(2-fluoro-5-methoxyphenyl)buto-3-en-2-one, 4-(3-fluoro-2-methoxyphenyl)buto-3-en-2-one, 4-(2-fluoro-6-methoxyphenyl)buto-3-en-2-one, 4-(3-fluoro-5-methoxyphenyl)buto-3-en-2-one, 4-(2-fluoro-3-methoxyphenyl)buto-3-en-2-one, and 4-(4-fluoro-2-hydroxyphenyl)buto-3-en-2-one.

[0030] In a second embodiment comprising an aliphatic linear or branched fluorinated α,β-unsaturated carbonyl compound, in addition to tin ions and any alloying metal ions selected from silver ions, indium ions, and bismuth ions, the electroplating composition is of formula L1b [ka] (In the formula, R L11 , R L12 , R L13 R L1 and R L2 Selected independently from, R L11 , R L12 , R L13 At least one, preferably two, most preferably all of R L1 This is conditional on the fact that, R L1 Each base R L1n Independently, F or linear or branched C1 or C2 fluorinated C1-C6 alkyl groups are selected. R L2 C1-C6 alkyl, C1-C6 alkenyl, C5-C 12 Aryl, C6~C 15 Alkylaryl, C6~C 15 These are arylalkyl groups, and they may all be substituted with CN, OH, C1-C6 alkoxy or halogen, especially fluorine. R L3 The group is selected from H, C1-C6 alkyl, C1-C6 alkenyl, C1-C6 alkoxy, halogen, CN, and OH. R L4 Each R L4 R L1 and R L3 (Selected from) It contains at least one additive represented by .

[0031] The additives according to the present invention may be prepared by any preparation method. A preferred method for preparing fluorinated phenyl α,β-unsaturated carbonyl compounds is by the Wittig reaction of each substituted benzaldehyde with, for example, a triphenylphosphonium ylide derivative, as described in Bioorganic & Medicinal Chemistry, 2012, 20(2), 1029-1045.

[0032] In a method for preparing α,β-unsaturated carbonyl compounds, additional compounds may be used, for example, to introduce specific substituents to the smoothing agent, to establish defined properties, or to enable further reactions with the smoothing agent obtained at a later point in time. The compositions described herein may further comprise one or more surfactants and one or more crystallizing agents, which are different from the fluorinated α,β-unsaturated carbonyl compounds described above, as additives.

[0033] Further smoothing agents Those skilled in the art will understand that more than one smoothing agent may be used. When two or more smoothing agents are used, at least one of the smoothing agents is a fluorinated α,β-unsaturated carbonyl compound or a derivative thereof as described herein. It is preferable to use only one or more fluorinated α,β-unsaturated carbonyl compounds as smoothing agents in the plating bath composition.

[0034] Suitable additional smoothing agents include, but are not limited to, polyaminoamides and their derivatives, polyalkanolamines and their derivatives, polyethyleneimines and their derivatives, quaternary polyethyleneimines, polyglycine, poly(allylamine), polyaniline, polyurea, polyacrylamide, poly(melamine-co-formaldehyde), reaction products of amines with epichlorohydrin, reaction products of amines with epichlorohydrin and polyalkylene oxides, reaction products of amines with polyepoxides, polyvinylpyridine, polyvinylimidazole, polyvinylpyrrolidone or copolymers thereof, nigrosine, pentamethyl-para-rosaniline hydrogenhalides, hexamethyl-pararosaniline hydrogenhalides, or compounds containing a functional group represented by the formula NRS (wherein R is a substituted alkyl, an unsubstituted alkyl, a substituted aryl, or an unsubstituted aryl). Typically, the alkyl group is a C1-C6 alkyl, and preferably a C1-C4 alkyl. Generally, aryl groups are C6~C 20 Aryl, preferably C6-C 12 It contains an aryl group. Such an aryl group may further contain heteroatoms such as sulfur, nitrogen, and oxygen. The aryl group is preferably phenyl or naphthyl. Compounds containing the functional group represented by formula NRS are generally known, commercially available, and can be used without further purification.

[0035] In such compounds containing N-R-S functional groups, sulfur ("S") and / or nitrogen ("N") may be bonded to the rest of the molecule via a single bond or a double bond. When sulfur is bonded to the rest of the molecule via a single bond, sulfur may have another substituent, such as, but not limited to, hydrogen, C1 to C 12 alkyl, C2 to C 12 alkenyl, C6 to C 20 aryl, C1 to C 12 alkylthio, C2 to C 12 alkenylthio, C6 to C 20 arylthio, and the like. Similarly, nitrogen will have one or more substituents, such as, but not limited to, hydrogen, C1 to C 12 alkyl, C2 to C 12 alkenyl, C7 to C 10 aryl, and the like. The N-R-S functional group may be acyclic or cyclic. Compounds containing cyclic N-R-S functional groups include those having either nitrogen or sulfur, or both nitrogen and sulfur in the ring system.

[0036] A further leveling agent is the triethanolamine condensate described in the unpublished International Patent Application No. PCT / EP2009 / 066581.

[0037] In general, the total amount of the leveling agent in the electroplating bath is 0.5 ppm to 10000 ppm relative to the total mass of the plating bath. The leveling agent according to the present invention is typically used in a total amount of about 100 ppm to about 10000 ppm relative to the total mass of the plating bath, although larger or smaller amounts may be used.

[0038] Typically, a wide variety of additives may be used in the bath to bring about a desired surface finish on plated tin or tin alloy bumps. Usually, more than one additive is used, each contributing to the desired function. Advantageously, the electroplating bath may contain one or more surfactants, crystal refiners, complexing agents in the case of alloy deposition, antioxidants, and mixtures thereof. Most preferably, the electroplating bath contains a surfactant and optionally a crystal refiner, in addition to the smoothing agent according to the present invention. Other additives are also suitably used in the electroplating bath of the present invention.

[0039] surfactant The composition may contain one or more nonionic surfactants. Typically, the nonionic surfactant has an average molecular weight of 200 to 100,000, preferably 500 to 50,000, more preferably 500 to 25,000, and even more preferably 750 to 15,000. Such nonionic surfactants are typically present in the electrolyte composition at a concentration of 1 to 10,000 ppm, preferably 5 to 10,000 ppm, based on the mass of the composition. Preferred alkylene oxide compounds include polyalkylene glycols, for example, alkylene oxide addition products of organic compounds having at least one hydroxyl group and 20 or fewer carbon atoms, and tetrafunctional polyethers derived from the addition of different alkylene oxides to low molecular weight polyamine compounds.

[0040] Preferred polyalkylene glycols are polyethylene glycol and polypropylene glycol. Such polyalkylene glycols are generally commercially available from various sources and may be used without further purification. Capped polyalkylene glycols, in which one or more terminal hydrogens are replaced by hydrocarbyl groups, can also be suitably used. An example of a preferred polyalkylene glycol is the formula RO-(CXYCX'Y'O) n It is represented by R', where R and R' are independent of H and C2~C 20 Alkyl and C6-C 20The groups are selected from aryl groups, where X, Y, X', and Y' are each independently selected from hydrogen, alkyl groups such as methyl, ethyl, or propyl, aryl groups such as phenyl, or aralkyl groups such as benzyl, and n is an integer between 5 and 100,000. Typically, one or more of X, Y, X', and Y' are hydrogen.

[0041] Suitable EO / PO copolymers generally have an EO:PO mass ratio of 10:90 to 90:10, preferably 10:90 to 80:20. Such EO / PO copolymers preferably have an average molecular weight of 750 to 15,000. Such EO / PO copolymers are available from various sources, for example, those marketed by BASF under the trade name "PLURONIC®".

[0042] Suitable alkylene oxide condensation products of organic compounds having at least one hydroxyl group and 20 or fewer carbon atoms include those having aliphatic hydrocarbons with 1 to 7 carbon atoms, unsubstituted aromatic compounds having 6 or fewer carbon atoms in the alkyl moiety, or alkylated aromatic compounds, for example, those disclosed in US5174887. The aliphatic alcohol may be saturated or unsaturated. Suitable aromatic compounds have up to two aromatic rings. The aromatic alcohol has up to 20 carbon atoms before derivatization with ethylene oxide. Such aliphatic and aromatic alcohols may be further substituted, for example, with a sulfate group or a sulfonate group.

[0043] Crystallization agent The tin or tin alloy electroplating bath may further contain a crystal refiner different from the smoothing agent according to the present invention. The crystal refiner is of formula G1 or G2 [ka] (In the formula, each R 1 R is independently a C1-C6 alkyl, C1-C6 alkoxy, hydroxy, or halogen, 2 and R 3R is independently selected from H and C1-C6 alkyl groups. 4 R is H, OH, C1-C6 alkyl, or C1-C6 alkoxy, m is an integer from 0 to 2, and each R 5 Each of them is independently a C1-C6 alkyl group, and each R 6 (where n is independently selected from H, OH, C1-C6 alkyl or C1-C6 alkoxy, n is 1 or 2, and p is 0, 1 or 2) You may select from the compounds represented by [formula].

[0044] Preferably, each R 1 R is independently a C1-C6 alkyl, C1-C3 alkoxy, or hydroxyl group, more preferably a C1-C4 alkyl, C1-C2 alkoxy, or hydroxyl group. 2 and R 3 Preferably, R is independently selected from H and C1-C3 alkyl groups, more preferably from H and methyl groups. Preferably, 4 H, OH, C 1 ~C 4 Alkyl or C1-C4 alkoxy, more preferably H, OH, or C1-C4 alkyl. 5 The C1-C4 alkyl group is more preferably a C1-C3 alkyl group. Each R 6 The first crystal refiner may be a mixture of the first crystal refiner, for example, two different crystal refiners represented by formula 1, two different crystal refiners represented by formula 2, or a mixture of the crystal refiner represented by formula 1 and the deluxe crystal refiner of formula 2.

[0045] Examples of compounds useful as such crystal refiners include, but are not limited to, cinnamic acid, cinnamaldehyde, benzylideneacetone, picolinic acid, pyridinedicarboxylic acid, pyridinecarboxyaldehyde, pyridinedicarboxyaldehyde, or mixtures thereof. Preferred crystal refiners include benzalacetone, 4-methoxybenzaldehyde, benzylpyridine-3-carboxylate, and 1,10-phenanthroline.

[0046] Further crystallization agents may be selected from α,β-unsaturated aliphatic carbonyl compounds. Suitable α,β-unsaturated aliphatic carbonyl compounds include, but are not limited to, α,β-unsaturated carboxylic acids, α,β-unsaturated carboxylic acid esters, α,β-unsaturated amides, and α,β-unsaturated aldehydes. Preferably, such crystallization agents are selected from α,β-unsaturated carboxylic acids, α,β-unsaturated carboxylic acid esters, and α,β-unsaturated aldehydes, and more preferably from α,β-unsaturated carboxylic acids and α,β-unsaturated aldehydes. Exemplary α,β-unsaturated aliphatic carbonyl compounds include (meth)acrylic acid, crotonic acid, C-C6 alkyl meth)acrylate, (meth)acrylamide, C1-C6 alkyl crotonate, crotonamide, crotonaldehyde, (meth)acrolein, or mixtures thereof. Preferred α,β-unsaturated aliphatic carbonyl compounds are (meth)acrylic acid, crotonic acid, crotonaldehyde, (meth)acrylaldehyde, or mixtures thereof.

[0047] The crystal refiner may be present in the plating bath of the present invention in an amount of 0.0001 to 0.045 g / l. Preferably, the crystal refiner is present in an amount of 0.0001 to 0.04 g / l, more preferably 0.0001 to 0.035 g / l, and even more preferably 0.0001 to 0.03 g / l. Compounds useful as the first crystal refiner are generally commercially available from various sources and may be used as is or further purified.

[0048] The composition may optionally contain further additives, such as antioxidants, organic solvents, complexing agents, and mixtures thereof. Additional smoothing agents may be used in the plating bath, but it is preferable that the plating bath contains only the smoothing agent according to the present invention.

[0049] Antioxidant Antioxidants may optionally be added to the composition to help maintain tin in a soluble divalent state. It is preferable to use one or more antioxidants in the composition. Exemplary antioxidants include, but are not limited to, hydroquinones, hydroxylated and / or alkoxylated aromatic compounds (including sulfonic acid derivatives of such aromatic compounds), preferably hydroquinone, methylhydroquinone, resorcinol, catechol, 1,2,3-trihydroxybenzene, 1,2-dihydroxybenzene-4-sulfonic acid, 1,2-dihydroxybenzene-3,5-disulfonic acid, 1,4-dihydroxybenzene-2-sulfonic acid, 1,4-dihydroxybenzene-2,5-disulfonic acid, 2,4-dihydroxybenzenesulfonic acid, and p-methoxyphenol. Such antioxidants are disclosed in US4871429. Other suitable antioxidants or reducing agents include, but are not limited to, vanadium compounds such as vanadylacetylacetonate, vanadium triacetylacetonate, vanadium halides, vanadium oxyhalides, vanadium alkoxides, and vanadyl alkoxides. The concentrations of such reducing agents are well known to those skilled in the art, but are typically in the range of 0.1 to 10 g / l, preferably 1 to 5 g / l. Such antioxidants are generally commercially available from various sources. It is particularly preferable to use the aforementioned antioxidants in pure tin electroplating compositions.

[0050] Complexing agent A tin or tin alloy electroplating bath may further contain a complexing agent for complexing tin and / or other metals present in the composition. A typical complexing agent is 3,6-dithia-1,8-octanediol. Further useful complexing agents are described in WO2019 / 185468 and unpublished international patent application number PCT / EP2020 / 075080.

[0051] Typical complexing agents include polyoxymonocarboxylic acids, polycarboxylic acids, aminocarboxylic acids, lactone compounds, and salts thereof.

[0052] Other complexing agents include organic thio compounds such as thiourea, thiols, or thioethers, as disclosed in US7628903, JP4296358B2, EP0854206A, and US8980077B2.

[0053] electrolyte Generally, as used herein, “aqueous” means that the electroplating composition of the present invention contains a solvent comprising at least 50% water. Preferably, “aqueous” means that the majority of the composition is water, more preferably 90% of the solvent is water, and most preferably the solvent is essentially water. Any type of water may be used, such as distilled water, deionized water, or tap water.

[0054] Suzu The tin ion source may be any compound that releases metal ions and can be deposited in sufficient quantities in the electroplating bath, i.e., it is at least partially soluble in the electroplating bath. Preferably, the metal ion source is soluble in the plating bath. Suitable metal ion sources are metal salts, but are not limited to, metal sulfates, metal halides, metal acetates, metal nitrates, metal fluoroborates, metal alkyl sulfonates, metal aryl sulfonates, metal sulfamates, and metal gluconates.

[0055] In this invention, the metal ion source may be used in any amount that supplies sufficient metal ions to electroplat the substrate. When the metal is tin alone, the tin salt is typically present in the plating solution in an amount ranging from about 1 to about 300 g / l.

[0056] Alloying metals Optionally, the plating bath according to the present invention may contain one or more alloying metal ions. Suitable alloying metals include, but are not limited to, silver, gold, copper, bismuth, indium, zinc, antimony, manganese, and mixtures thereof. Preferred alloying metals are silver, copper, bismuth, indium, and mixtures thereof, and more preferably silver. The composition of the present invention is preferably lead-free. Any salt of an alloying metal soluble in the bath is suitably used as a source of alloying metal ions. Examples of such alloying metal salts include, but are not limited to, metal oxides, metal halides, metal fluoroborates, metal sulfates, metal alkanesulfonates, e.g., metal methanesulfonates, metal ethanesulfonates, and metal propanesulfonates, metal arylsulfonates, e.g., metal phenylsulfonates, metal toluenesulfonates, and metal phenolsulfonates, metal carboxylates, e.g., metal gluconates and metal acetates. Preferred alloying metal salts are metal sulfates, metal alkanesulfonates, and metal arylsulfonates. When one alloying metal is added to the composition, the precipitation of a binary alloy is achieved. When two or more different alloying metals are added to the composition, the precipitation of tertiary, quaternary, or even higher-order alloys is achieved. The amount of such alloying metal used in the composition depends on the specific tin alloy desired. The selection of such amounts of alloying metal is within the capabilities of those skilled in the art. Those skilled in the art will understand that when a particular alloying metal, such as silver, is used, additional complexing agents may be required. Such complexing agents (or complexers) are well known in the art and may be used in any suitable amount.

[0057] The electroplating compositions of the present invention are suitable for depositing tin-containing layers (which may be pure tin layers or tin alloy layers). Exemplary tin alloy layers include, but are not limited to, tin-silver, tin-copper, tin-indium, tin-bismuth, tin-silver-copper, tin-silver-copper-antimony, tin-silver-copper-manganese, tin-silver-bismuth, tin-silver-indium, tin-silver-zinc-copper, and tin-silver-indium-bismuth. Preferably, the electroplating compositions of the present invention deposit pure tin, tin-silver, tin-silver-copper, tin-silver-bismuth, tin-silver-indium, and tin-silver-indium-bismuth, and more preferably pure tin, tin-silver, or tin-copper.

[0058] The alloy deposited from the electroplating bath of the present invention, when measured by atomic adsorption spectroscopy (AAS), X-ray fluorescence (XRF), inductively coupled plasma mass spectrometry (ICP-MS), or differential scanning calorimetry (DSC), contains 0.01 to 99.99% by mass of tin and 99.99 to 0.01% by mass of one or more alloying metals relative to the mass of the alloy. Preferably, the tin-silver alloy deposited using the present invention contains 90 to 99.99% by mass of tin and 0.01 to 10% by mass of silver and any other alloying metal. More preferably, the tin-silver alloy deposition contains 95 to 99.9% by mass of tin and 0.1 to 5% by mass of silver and any other alloying metal. The tin-silver alloy is a preferred tin alloy deposition, and preferably contains 90 to 99.9% by mass of tin and 10 to 0.1% by mass of silver. More preferably, the tin-silver alloy precipitate contains 95-99.9% by mass of tin and 5-0.1% by mass of silver. In many applications, the eutectic composition of the alloy is used. The alloy precipitated according to the present invention is substantially lead-free, i.e., contains 1% by mass, more preferably less than 0.5% by mass, and even more preferably less than 0.2% by mass of lead, and still more preferably lead-free.

[0059] bath Generally, in addition to the metal ion source and at least one smoothing agent according to the present invention, the metal electroplating composition of the present invention preferably includes an electrolyte, i.e., an acidic or alkaline electrolyte, one or more metal ion sources, any halide ions, and any other additives (such as surfactants and crystal refiners). Such a bath is typically aqueous. Water can be present in a wide range of amounts. Any type of water may be used, such as distilled water, deionized water, or tap water.

[0060] Preferably, the plating bath of the present invention is acidic, i.e., has a pH of less than 7. Typically, the pH of the tin or tin alloy electroplating composition is less than 4, preferably less than 3, and most preferably less than 2.

[0061] The electroplating bath of the present invention may be prepared by combining the components in any order. Preferably, inorganic components, such as a metal salt, water, an electrolyte, and an optional halide ion source, are first added to the bath, and then organic components, such as a surfactant, a crystal refiner, a smoothing agent, etc., are added.

[0062] Typically, the plating bath of the present invention may be used at any temperature of 10 to 65°C or higher. The temperature of the plating bath is preferably 10 to 35°C, and more preferably 15 to 30°C.

[0063] Suitable electrolytes include, but are not limited to, sulfuric acid, acetic acid, fluoroboric acid, alkyl sulfonic acids such as methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, and trifluoromethanesulfonic acid, aryl sulfonic acids such as phenylsulfonic acid and toluenesulfonic acid, sulfamic acid, hydrochloric acid, phosphoric acid, tetraalkylammonium hydroxide, preferably tetramethylammonium hydroxide, sodium hydroxide, potassium hydroxide, and the like. The acid is typically present in an amount ranging from about 1 to about 300 g / l.

[0064] In one embodiment, at least one additive is a counterion Y selected from chloride, sulfate, or acetate. o- The expression includes , where o is a positive integer.

[0065] Such electrolytes may optionally contain a halide ion source, such as chloride ions found in tin chloride or hydrochloric acid. A wide range of halide ion concentrations, for example, about 0 to about 500 ppm, may be used in the present invention. Typically, the halide ion concentration is in the range of about 10 to about 100 ppm relative to the plating bath. The electrolyte is preferably sulfuric acid or methanesulfonic acid, and preferably a mixture of sulfuric acid or methanesulfonic acid and a chloride ion source. Acids and halide ion sources useful in the present invention are generally commercially available and may be used without further purification.

[0066] Purpose The plating composition of the present invention is useful in various plating methods for depositing a tin-containing layer, and in particular a tin-containing solder layer, on a semiconductor wafer containing multiple conductive junctions. Plating methods include, but are not limited to, horizontal or vertical wafer plating, barrel plating, rack plating, high-speed plating, such as open-reel and jet plating, and rackless plating, and preferably horizontal or vertical wafer plating. A wide variety of substrates can be plated with the tin-containing precipitate according to the present invention. The substrate to be plated is conductive and may contain copper, copper alloys, nickel, nickel alloys, or nickel-iron-containing materials. Such substrates may be in the form of electronic components, such as (a) lead frames, connectors, chip capacitors, chip resistors, and semiconductor packages, (b) plastics such as circuit boards, and (c) semiconductor wafers. Preferably, the substrate is a semiconductor wafer. Accordingly, the present invention also provides a method for depositing a tin-containing layer on a semiconductor wafer, comprising: manufacturing a semiconductor wafer including a plurality of conductive bonding portions; contacting the semiconductor wafer with the above composition; and applying a sufficient current density to deposit the tin-containing layer on the conductive bonding portions. Preferably, the bonding portions include copper, a copper alloy layer, or any interconnection structure containing copper, which may be in the form of a pure copper layer. A copper pillar is one preferred conductive bonding portion. Optionally, the copper pillar may include an upper metal layer, such as a nickel layer. If the conductive bonding portion has an upper metal layer, a solder layer of tin or a tin alloy is deposited on the upper metal layer of the bonding portion. Conductive bonding portions such as bonding pads and copper pillars are well known in the art and are described, for example, in US7,781,325, US2008 / 0054459A, US2008 / 0296761A, and US2006 / 0094226A.

[0067] method One embodiment of the present invention is a method of using an additive represented by formula L1 and any other smoothing agent described herein in a bath for depositing a tin or tin alloy-containing layer, wherein the tin alloy-containing layer contains an alloying metal selected from silver, copper, indium, and bismuth in an amount of 0.01 to 10% by mass. Preferably, the deposited tin alloy layer has an alloying metal content of 0.1 to 5% by mass.

[0068] Another embodiment of the present invention is a method for depositing a tin or tin alloy layer on a substrate, comprising the following steps a) A tin ion and a further alloying metal ion selected from silver, copper, indium, and bismuth ions, and formula L1a [ka] or formula L1b [ka] A step of bringing a tin alloy electroplating bath containing a composition comprising at least one additive represented by into contact with a substrate, and b) The process of applying an electric current to the substrate for a sufficient time to deposit a tin or tin alloy layer onto the substrate. This is a method that involves During the ceremony, R L1 Each base R L1 n Independently, selected from linear or branched C1-C6 alkyl groups containing one or more F substituents at the -F, C1, or C2 position, R L2 C1-C6 alkyl, C1-C6 alkenyl, C5-C 12 Aryl, C6~C 15 Alkylaryl, C6~C 15 These are arylalkyl groups, and they may all be substituted with CN, OH, C1-C6 alkoxy or halogen, especially fluorine. R L3 The elements are H, C1-C6 alkyl, C1-C6 alkenyl, C1-C6 alkoxy or halogen, Cl, CN, and OH, preferably R L1 Or selected from H, R L4 R L1 or R L3 And, R L11 , R L12 , R L13 R L1 and R L3 Selected independently from, R L11 , R L12 , R L13 At least one, preferably two, most preferably all of R L1 This is conditional on the fact that, X L1 (a) Divalent saturated and unsaturated groups, as follows: (a) C3-C5 alkanediyl group, (b) C3-C5 alkenediyl group, Selected from, or (c) C5~C together with adjacent C=C double bonds 12 Forming an aromatic ring system, and n is a base R selected from 1, 2, or 3. L1 It is the number of [number].

[0069] As used herein, "recessed feature" refers to vias, trenches, or any other openings in the substrate, specifically openings for depositing solder bumps. As used herein, "aperture size" refers to the shortest distance across the opening of the recessed feature.

[0070] Preferably, the substrate includes a recessed characteristic shape having an aperture size of 1 to 1000 micrometers, and the deposition is carried out to at least partially fill the micrometer-sized recessed characteristic shape. Most preferably, the recessed characteristic shape has an aperture size of 1 to 200 micrometers, preferably 3 to 100 micrometers.

[0071] Generally, when depositing tin or a tin alloy on a substrate using the present invention, the plating bath is stirred during use. Preferably, a tin alloy is deposited, and the alloy metal content of the deposited tin alloy is 0.01 to 10% by mass. Any suitable stirring method may be used in conjunction with the present invention, and such methods are well known in the art. Suitable stirring methods include, but are not limited to, spraying with an inert gas or air, stirring the workpiece, and impacting. Such methods are known to those skilled in the art. When plating an integrated circuit substrate such as a wafer using the present invention, the wafer may be rotated, for example, at 1 to 150 RPM, and the plating solution may be brought into contact with the rotating wafer, for example, by a pump or spray. In an alternative embodiment, if the flow of the plating bath is sufficient to provide the desired metal deposit, it is not necessary to rotate the wafer.

[0072] Tin or a tin alloy is deposited in the recesses of the metal precipitate without substantially forming voids. The term "substantially forming voids" means that there are no voids in the metal precipitate larger than 1000 nm, preferably 500 nm, and most preferably 100 nm.

[0073] Plating equipment for plating semiconductor substrates is well known. The plating equipment includes an electroplating bath made of a suitable material, such as plastic or another material inert to the electroplating solution, which holds a tin or tin alloy electrolyte. The bath may be cylindrical, particularly for wafer plating. The cathode is positioned horizontally at the top of the bath and may be any type of substrate, such as a silicon wafer with an opening.

[0074] These additives can be used with soluble and insoluble anodes, either in the presence or absence of a membrane(s) that separates the cathode liquid from the anode liquid.

[0075] The cathode substrate and the anode are electrically connected to the power supply unit by wiring. For DC or pulsed current, the cathode substrate has a net negative charge, and therefore metal ions in the solution are reduced on the cathode substrate, forming a plated metal on the cathode surface. An oxidation reaction occurs at the anode. The cathode and anode may be arranged horizontally or vertically in the tank.

[0076] Generally, when manufacturing tin or tin alloy bumps, a photoresist layer is applied to a semiconductor wafer, followed by standard photolithography exposure and development techniques to form a patterned photoresist layer (or plating mask) with openings or vias. The dimensions of the plating mask (thickness of the plating mask and size of the openings in the pattern) define the size and position of the tin or tin alloy layer deposited on the I / O pads and UBM.

[0077] All percentages, ppm, or equivalent values ​​refer to the mass relative to the total mass of each composition, unless otherwise specified. All references are incorporated herein by reference.

[0078] The following examples further illustrate the present invention without limiting its scope. [Examples]

[0079] The method used here The molecular weight of the polymer ion compound was determined by size exclusion chromatography (SEC).

[0080] The morphology (roughness) was determined by measuring the height of the substrate using a laser scanning microscope (LSM).

[0081] The patterned photoresist contained vias with a diameter of 8 μm and a depth of 15 μm, and pre-formed copper μbumps with a height of 5 μm. The isolated (iso) regions consisted of a 3 × 6 pillar array with a distance between centers (pitch) of 32 μm. The high-density regions consisted of an 8 × 16 pillar array with a distance between centers (pitch) of 16 μm.

[0082] Average roughness R a is, formula

number

[0083] Here, H i H is the height of position i on a specific bump. When laser scanning the surface of one bump, the heights of n positions are determined. 平均 This is the average height of all n positions on a single bump.

[0084] Examples The following lubricants were used in the following examples: Smoothing agent 1: 4-[4-(difluoromethyl)phenyl]buto-3-en-2-one, available from Aurora Fine Chemicals. Smoothing agent 2: 4-(4-(trifluoromethyl)phenyl)buto-3-en-2-one, available from Merck KGaA. Smoothing agent 3:4-(4-fluorophenyl)-buto-3-en-2-one, available from Chemieliva Pharmaceuticals Co.

[0085] Comparative Example 1 A tin plating bath was prepared containing different amounts of stock solution of 75 g / l tin as tin methanesulfonate, 180 g / l methanesulfonic acid, 0.3 g / l of a commercially available antioxidant, and 1.5 g / l of benzalacetone in isopropanol.

[0086] 10 μm tin was electroplated onto copper microbumps. The copper microbumps had a diameter of 25 μm and a height of 25 μm. A large 2.5 cm × 2.5 cm wafer coupon with a 50 μm thick patterned photoresist layer was immersed in the above plating bath, and a DC current density of 10 ASD was applied for 300 seconds at 25°C. The plated tin bumps were inspected using a laser scanning microscope (LSM).

[0087] The results are shown in Table 1.

[0088] Example 2 A tin plating bath described in Comparative Example 1 was prepared, containing smoothing agent 1 instead of benzalacetone. The plating procedure was the same as described in Comparative Example 1. The plated tin bumps were observed using a laser scanning microscope (LSM).

[0089] The results are summarized in Table 1.

[0090] Comparing the results with Comparative Example 1, tin electroplating yielded a smoother surface when using smoothing agent 1 compared to benzalacetone. Furthermore, experiments with varying smoothing agent concentrations showed that smoothing agent 1 had a wider process window than benzalacetone.

[0091] Example 3 A tin plating bath described in Comparative Example 1 was prepared, containing smoothing agent 2 instead of benzalacetone. The plating procedure was the same as described in Comparative Example 1. The plated tin bumps were observed using a laser scanning microscope (LSM).

[0092] The results are summarized in Table 1.

[0093] Comparing the results with Comparative Example 1, tin electroplating yielded a smoother surface when using smoothing agent 2 compared to benzalacetone. Furthermore, in experiments with varying smoothing agent concentrations, smoothing agent 2 showed a wider process window compared to benzalacetone, especially at low concentrations.

[0094] Example 4 A tin plating bath described in Comparative Example 1 was prepared, containing smoothing agent 3 instead of benzalacetone. The plating procedure was the same as described in Comparative Example 1. The plated tin bumps were observed using a laser scanning microscope (LSM).

[0095] The results are summarized in Table 1.

[0096] Compared to Comparative Example 1, tin electroplating yielded a smoother surface when using smoothing agent 3 compared to benzalacetone. Furthermore, experiments with varying smoothing agent concentrations showed that smoothing agent 3 had a wider process window compared to benzalacetone.

[0097] [Table 1]

Claims

1. An aqueous composition comprising tin ions, an alloying metal ion optionally selected from silver ions, indium ions, and bismuth ions, and formula L1a 【Chemistry 1】 (In the formula, R Ｌ１ Each base R Ｌ１ ｎ Regarding F and C, independently, １ or C ２ Linear or branched C2 containing one or more F substituents at the position １ ~C ６ Selected from alkyl groups, R Ｌ２ is C １ to C ６ alkyl, C １ to C ６ alkenyl, C ５ to C １２ aryl, C ６ to C １５ alkylaryl, C ６ to C １５ arylalkyl, all of which may be substituted by CN, OH, C １ to C ６ alkoxy or halogen, R Ｌ３ H, C １ ~C ６ Alkyl, C １ ~C ６ Alkenil, C １ ~C ６ Selected from alkoxy, halogen, CN, and OH, R Ｌ４ Each R Ｌ４ R Ｌ１ and R Ｌ３ Selected from, X Ｌ１ C=C double bond ５ ~C １２ Forming an aromatic ring system, and n is a base R selected from 1, 2, or 3. Ｌ１ (The number of) An aqueous composition comprising at least one additive represented by .

2. R Ｌ１ However, -F, -CR Ｌ３ ２ F, -CR Ｌ３ F ２ , -CF ３ Selected from, R Ｌ３ However, H and C １ ~C ６ The composition according to claim 1, selected from alkyl groups.

3. R Ｌ１ However, -F and -CF ３ A composition according to claim 1, selected from the following.

4. R Ｌ２ The composition according to any one of claims 1 to 3, wherein the compound is selected from methyl, ethyl, 1-propyl, 2-propyl, tert-butyl, and benzylidene, which may be unsubstituted or substituted with F or CN.

5. The aforementioned additive is, Formula L3 【Chemistry 2】 The composition according to any one of claims 1 to 4, wherein the compound is represented by .

6. The aforementioned additive is formula L3a 【Transformation 3】 or formula L3b 【Chemistry 4】 The composition according to any one of claims 1 to 4, wherein the compound is represented by .

7. The composition according to any one of claims 1 to 6, wherein the alloy metal ion contains a silver ion.

8. The composition according to any one of claims 1 to 7, wherein the pH is less than 4.

9. The composition according to any one of claims 1 to 8, further comprising one or more surfactants and one or more crystallizing agents as further additives.

10. In a bath for depositing a tin or tin alloy-containing layer, formula L1a 【Transformation 5】 (In the formula, R Ｌ１ Each base R Ｌ１ ｎ Regarding F and C, independently, １ or C ２ Linear or branched C2 containing one or more F substituents at the position １ ~C ６ Selected from alkyl groups, R Ｌ２ C １ ~C ６ Alkyl, C １ ~C ６ Alkenil, C ５ ~C １２ Ariel, C ６ ~C １５ Alkylaryl, C ６ ~C １５ These are arylalkyls, and they all consist of CN, OH, and C. １ ~C ６ They are often substituted with alkoxy or halogens. R Ｌ３ H, C １ ~C ６ Alkyl, C １ ~C ６ Alkenil, C １ ~C ６ Selected from alkoxy, halogen, CN, and OH, R Ｌ４ Each R Ｌ４ R Ｌ１ and R Ｌ３ Selected from, X Ｌ１ C=C double bond ５ ~C １２ Forming an aromatic ring system, and n is a base R selected from 1, 2, or 3. Ｌ１ (The number of) A method for using an additive comprising the additive represented by, wherein the tin alloy-containing layer contains an alloying metal selected from silver, copper, indium, and bismuth in an amount of 0.01 to 10% by mass.

11. The method of use according to claim 10, wherein the precipitated tin alloy layer has an alloy metal content of 0.1 to 5% by mass.

12. A method for depositing a tin or tin alloy layer on a substrate, comprising the following steps: a) A step of bringing a tin alloy electroplating bath containing the composition described in any one of claims 1 to 9 into contact with a substrate, and b) The step of applying an electric current to the substrate for a time sufficient to deposit the tin or tin alloy layer onto the substrate. A method using [a specific method].

13. The method according to claim 12, wherein a tin alloy is precipitated, and the alloy metal content of the precipitated tin alloy is 0.01 to 10% by mass.

14. The method according to claim 13, wherein the substrate includes a recessed characteristic shape having an aperture size of 1 to 1000 micrometers, and deposition is carried out to at least partially fill the recessed characteristic shape of micrometer size.

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