Acidic aqueous composition for electrolytically depositing copper deposits

Abstract

The present invention relates to an acidic aqueous composition for electrolytic copper plating, comprising: (i) copper(II) ions; and (ii) one or more suppressors consisting of or comprising a single N-heteroaromatic monocycle containing at least two ring nitrogen atoms and more than one substituent covalently bonded to one of the ring nitrogen atoms and / or to a ring carbon atom, wherein the substituents are independently one or more linear or branched polyalkylene glycol moieties, and / or one or more linear or branched polyalkylene glycol block polyalkylene glycol, or random polyalkylene glycol moieties, with the proviso that if the suppressor comprises an OH group, it is the terminal OH group of each of the polyalkylene glycol moieties, polyalkylene glycol block polyalkylene glycol, and random polyalkylene glycol moieties, and the suppressor does not comprise an NH group, a halogen atom, or a sulfur atom; a method of electrolytic copper plating using the acidic aqueous composition; and a specific suppressor as defined above.

Description

[Technical Field]

[0001] The present invention relates to an acidic aqueous composition (plating bath) for electrolytic copper plating (electrolytic deposition of copper), comprising copper(II) ions and one or more suppressors as defined below, to an electrolytic copper plating method using the acidic aqueous composition according to the invention, and to a specific suppressor as defined above for electrolytically depositing a copper deposit.

[0002] The acidic aqueous composition according to the present invention is suitable for the electrolytic deposition of copper, particularly for filling blind microvias (BMVs), through-vias, trenches, and similar structures. Thus, the method of the present invention is suitable for the manufacture of printed circuit boards (PCBs), integrated circuit (IC) substrates, and the like, as well as for the metallization of semiconductor and glass substrates. [Background technology]

[0003] Acidic aqueous compositions (aqueous acidic plating baths) for electrolytic copper plating (electrolytic deposition of copper) are used in the manufacture of printed circuit boards (PCBs) and IC substrates where fine structures such as trenches, through-holes (THs), blind microvias (BMVs), pillars, and bumps need to be filled or constructed with copper. Another application of such compositions is the filling or plating of recessed structures, such as through-silicon vias (TSVs) and dual damascene (DD) structures or features, or the formation of redistribution layers (RDLs) and pillar bumps.

[0004] As printed circuit boards continue to shrink in size, their design and complexity continues to increase, typically to increase computing capacity and / or functionality in an ever-decreasing amount of space. Accordingly, for example, the shapes of printed circuit boards, or conductor structures on printed circuit boards, chip carriers, and semiconductor wafers, are becoming increasingly complex and intricate. For example, the ratio of copper thickness to conductor path width or the ratio of hole depth to hole diameter (aspect ratio) continues to increase, as hole diameters become smaller and smaller and conductor paths become narrower, respectively.

[0005] It is generally accepted that structures exhibiting relatively high aspect ratios (e.g., 6:1 to 3:1) require advanced electrolytic copper plating methods because such structures exhibit variable electrodeposition behavior. In particular, our own experiments have shown that forming uniform and reliable conductor structures in trenches and vias on printed circuit boards using methods known in the art is often insufficient and extremely difficult. For example, due to the relatively increased aspect ratios of the structures (and therefore variable electrodeposition behavior), copper deposition often results in the formation of copper layers with uneven surfaces. However, uneven surfaces often pose additional challenges during chemical / mechanical polishing after copper deposition. Typically, the copper surface produced during the electrolytic deposition process must be extensively smooth and flat, a prerequisite for each polishing step, to ensure reliable metal removal to the desired depth. Furthermore, a smooth and flat surface contributes to a high level of reproducibility.

[0006] It is well known to add a number of different organic additives to aqueous compositions for electrolytic copper plating in order to be able to control the decorative and functional properties of the copper coating.

[0007] So-called "suppressors" can be used, which are "typically polymeric organic species, such as high molecular weight polyethylene or polypropylene glycol, that strongly adsorb to the copper cathode surface, forming a film that rapidly increases the overpotential for copper deposition. This prevents uncontrolled copper plating..." (see US 2005 / 0247577 A1, paragraph

[0007] ). Additionally, anti-suppressors (also known as "accelerators") can be used, whose purpose is to "counter the suppression effect of the suppressors and achieve accelerated deposition within the substrate recesses required for leveling" (again, see US 2005 / 0247577 A1, paragraph

[0007] ).

[0008] To obtain a properly copper-filled structure, further organic additives can typically be used as "levelers," which are "typically nitrogen-containing organic compounds that tend to reduce the copper plating rate" (US 2005 / 0247577 A1, paragraph

[0009] (See

[0009] JP 2013 023693 A discloses a copper plating bath containing an oxyalkylene compound having a terminal ring and bonded to an imidazole ring. This compound is believed to provide good solubility in water and high defoaming properties in the plating bath.

[0010] The above additives often have a positive effect on the uniform deposition and metallization of copper during the plating process. In very small structures that must be completely filled with copper, such additives have typically been shown to help avoid the formation of voids in the copper deposit.

[0011] Unfortunately, in some cases, organic additives are co-deposited with metal ions (e.g., copper ions), which can lead to undesirable effects such as increased electromigration and reliability issues. Generally, such co-deposition of additives is believed to increase when the additive's adhesion to the plating surface is too strong. Therefore, there is a need for additives that exhibit adequate adhesion.

[0012] Furthermore, it is believed that the copper filling quality of structures exhibiting relatively high aspect ratios (e.g., 6:1 to 3:1) is basically correlated with the overpotential generated in each acidic aqueous composition for electrolytic copper plating (J. Electrochem. Soc. 2004, 151, C702-C711).

[0013] There is a continuing need to provide new and improved acidic aqueous compositions for electrolytic copper plating (and respective plating methods) to obtain uniform, void-free copper deposits, which contain relatively low amounts of organic additives. Furthermore, each composition must exhibit adequate stability (shelf life).

[0014] EP 2 778 260 A2 discloses a method for filling through-holes. The disclosed method prevents or reduces dimple formation and voids during copper electroplating of through-holes with a flash copper layer in a substrate, such as a printed circuit board. EP 2 778 260 A2 discloses an acidic aqueous solution consisting essentially of one or more inorganic acids and one or more reaction products of one or more aromatic heterocyclic nitrogen compounds and one or more epoxy-containing compounds, wherein the one or more reaction products are present in an amount of 1 ppm to 50 ppm.

[0015] US 4,009,087 A relates to a method and novel compositions for electroplating copper from aqueous acid copper plating baths containing (i) an N-heteroaromatic compound containing one or two N-heteroaromatic rings and at least one component independently selected from each of two groups of sulfoalkylsulfide and sulfoarylsulfide compounds. [Prior art documents] [Patent documents]

[0016] [Patent Document 1] US 2005 / 0247577 A1 [Patent Document 2] JP 2013 023693 A [Patent Document 3] EP 2 778 260 A2 [Patent Document 4] US 4,009,087 A [Patent Document 5] US 5,976,341 [Patent Document 6] US 6,099,711 [Patent Document 7] EP 2735627 A1 [Patent Document 8] EP 2922985 A1 [Patent Document 9] EP 2113587 B9 [Patent Document 10] EP 3497267 [Patent Document 11] EP 2537962 A1 [Patent Document 12] WO 2016169952 A1 [Patent Document 13] DE 42 25 961 C2 [Patent Document 14] DE 27 39 427 A1 [Patent Document 15] DE 36 24 481 A1 [Patent Document 16] DE 32 36 545 A1 [Patent Document 17] International patent application WO2008157612A1 [Non-patent literature]

[0017] [Non-Patent Document 1] J. Electrochem. Soc. 2004, 151, C702~C711 Summary of the Invention [Problem to be solved by the invention]

[0018] An object of the present invention is to provide an acidic aqueous composition (plating bath) for electrolytic copper plating (electrolytic deposition of copper) that exhibits good plating quality during the electroplating process (i.e., essentially void-free and uniform copper deposits), particularly for substrates having structures exhibiting both low and high aspect ratios.

[0019] An additional object was to provide an acidic aqueous composition that exhibits an increased overvoltage compared to compositions that typically include polyethylene glycol (PEG) as an inhibitor additive.

[0020] Furthermore, it is desirable that such compositions exhibit adequate stability (shelf life) and provide copper deposits containing relatively low amounts of organic additives, i.e., exhibit adequate adhesion on copper surfaces.

[0021] Furthermore, it is an object of the present invention to provide respective methods for electrolytic copper plating (electrolytic deposition of copper) that allow, on the one hand, relatively rapid copper filling of structures exhibiting low and high aspect ratios, and, on the other hand, adequate plating quality (e.g., good surface distribution over the entire substrate and less codeposition of organic additives). [Means for solving the problem]

[0022] The above-mentioned objects are solved by an acidic aqueous composition for electrolytic copper plating and an inhibitor for electrolytically depositing copper deposits as described below, the composition comprising: (i) copper(II) ions; (ii) one or more inhibitors, - consisting of or comprising one single N-heteroaromatic monocycle containing at least two ring nitrogen atoms and more than one substituent covalently bonded to one of said ring nitrogen atoms and / or to a ring carbon atom, said substituents being independently - one or more linear or branched polyalkylene glycol moieties, and / or - being or comprising one or more linear or branched polyalkylene glycol, block polyalkylene glycol or random polyalkylene glycol moieties, however, - when the inhibitor contains an OH group, it is a terminal OH group of the polyalkylene glycol moiety, polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moiety, - the inhibitor does not contain NH groups, halogen atoms, and sulfur atoms; and an inhibitor.

[0023] Throughout the text, the suppressor used as compound (ii) in the acidic aqueous composition for electrolytic copper plating as described above will be referred to as "suppressor (ii)". Preferred embodiments of the suppressor (ii) are defined below.

[0024] The inhibitor preferably does not contain a group covalently bonded to one of the ring nitrogen atoms and / or to a ring carbon atom that is available for polymerization as a group having a double or triple bond between two carbon atoms, such as an alkenyl or alkynyl group.

[0025] Throughout this text, the term "the inhibitor is free of NH groups, halogen atoms, and sulfur atoms" means that the inhibitor does not contain NH groups, halogen atoms, and sulfur atoms covalently bonded within the organic structure of the inhibitor. In contrast, the inhibitor does not contain positively charged nitrogen atoms (N + When a suppressor contains a positively charged moiety (atom) as a cation (denoted as ), the negatively charged counter group is a negatively charged ionic counter group, which can be a halide such as chloride or a sulfur-containing group such as sulfate. The bond between the positively charged moiety in the organic structure and the negatively charged ionic counter group is an ionic bond (not a covalent bond); for example, a positively charged nitrogen atom remains covalently bonded to its neighboring atom in the organic structure of the suppressor. The negatively charged counter group does not itself affect the activity of the suppressor and can dissociate in an acidic aqueous composition for electrolytic copper plating.

[0026] If the inhibitor contains a positively charged moiety (atom) within the organic structure of the inhibitor, the inhibitor may be coupled to a negatively charged counter group X - Preferably, the negatively charged counter group is a negatively charged ionic counter group selected from the group consisting of sulfur-containing groups such as sulfates. More preferably, the inhibitor does not also include halides as negatively charged counter groups.

[0027] Throughout this text, the term "more than one" is understood to mean two or more, three or more, four or more, etc.

[0028] Furthermore, the purpose is (a) providing or manufacturing a substrate suitable for electrolytic copper plating; (b) contacting the substrate obtained after step (a), or after an additional step after step (a) but before step (b), with an acidic aqueous composition according to the present invention (as defined above, preferably as defined below as preferred), and applying an electric current so that copper is electrolytically plated as a copper deposit on the substrate; The problem is solved by an electrolytic copper plating method comprising: DETAILED DESCRIPTION OF THE INVENTION

[0029] Our own experiments (see the "Examples" section below) have shown that the acidic aqueous composition of the present invention typically provides very good copper filling (void-free) for structures exhibiting low and high aspect ratios (see "Examples"). Furthermore, it was possible to obtain very good surface distribution of copper deposition across the entire substrate. In other words, the copper thickness was very uniform everywhere on the substrate (for both pattern and panel plating).

[0030] Our own experiments have also shown that acidic aqueous compositions according to the invention (as defined above) exhibit a significant increase in overpotential compared to acidic aqueous compositions (not according to the invention) comprising polyethylene glycol instead of the compound of component (ii).

[0031] The acidic aqueous composition according to the present invention (as defined above) is an aqueous solution. The term "aqueous solution" means that the predominant liquid medium, i.e., the solvent in the composition, is water. In some cases, it is preferred that the composition comprises a liquid that is miscible with water. A preferred liquid is a water-miscible alcohol. For environmental reasons, water as the only solvent is preferred.

[0032] The acidic aqueous compositions according to the present invention (as defined above, preferably as preferred) are typically prepared by dissolving (and subsequent stirring) all of the components and compounds, respectively, in an aqueous liquid medium, preferably water.

[0033] The composition according to the present invention (as defined above, preferably as preferred) preferably contains one or more acids selected from the group consisting of sulfuric acid, fluoroboric acid, phosphoric acid and methanesulfonic acid. The total amount of the one or more acids in the composition according to the present invention is preferably in the range of 5 g / L to 400 g / L, more preferably in the range of 10 g / L to 300 g / L, relative to the total volume of the composition. If the total amount is much more than 400 g / L, the effect may be that bottom-up filling in the trenches may be insufficient. These acids are preferably counted among one, two, three or more further compounds.

[0034] The pH value of the composition according to the present invention (as defined above, preferably as preferred) is not more than 3, preferably not more than 2, measured at a temperature of 20°C. This means that the pH value of the composition of the present invention is not more than 3, preferably not more than 2. In the context of the present invention, the pH value is determined at a temperature of 20°C, i.e. the defined pH value is based on 20°C. Therefore, only for the purpose of determining the pH, the composition has a temperature of 20°C. This does not mean that the composition of the present invention itself is limited to the specific temperature of 20°C. For preferred temperatures of the composition, see below.

[0035] If the pH is significantly higher than 3, the effect is that the composition will have insufficient electrical conductivity, resulting in an unbalanced current density in the composition during plating. Furthermore, a pH of 3 or less prevents the formation of insoluble copper oxide. As a result, the composition of the present invention does not require a complexing agent. Therefore, it is preferred that the acidic aqueous composition for electrolytic copper plating according to the present invention is substantially free (preferably contains no) of a complexing agent. The absence of a complexing agent is preferred because it further minimizes the risk of introducing organic additives into the copper deposit. When the composition of the present invention does not contain a complexing agent, typically, no significant carbon content is observed in the copper deposit. Preferably, the electroplated copper obtained in the method of the present invention contains at least 99 wt.-% copper, more preferably at least 99.9 wt.-% copper, based on the total weight of the electroplated copper.

[0036] The acidic aqueous composition for electrolytic copper plating according to the present invention contains copper(II) ions. Preferably, the copper ion source is selected from the group consisting of copper sulfate, copper chloride, copper nitrate, copper fluoroborate, copper acetate, copper citrate, copper phenylsulfonate, copper paratoluenesulfonate, and copper alkylsulfonate. A preferred copper alkylsulfonate is copper methanesulfonate. The most preferred copper source is copper sulfate, most preferably CuSO4. * It is 5H2O.

[0037] Preferably, copper sulfate (CuSO4) in the acidic aqueous composition for electrolytic copper plating according to the present invention * The total amount of CuSO4 is 12 g / L to 275 g / L, preferably 20 g / L to 275 g / L, based on the total volume of the acidic aqueous composition. In some specific cases, a total amount of 30 g / L to 80 g / L is preferred, and in other specific cases, a total amount of 180 g / L to 220 g / L is preferred. * If a source other than 5H2O is used, the respective moles per liter of copper(II) ions can be calculated by one skilled in the art. * A total amount of copper(II) ions (regardless of copper source) corresponding to the aforementioned concentrations in g / L for 5H2O is preferred.

[0038] Generally, in the composition according to the invention (as defined above, preferably as preferred), the total amount of copper(II) ions is in the range of 3 to 70 g / L, preferably in the range of 5 to 70 g / L, relative to the total volume of the composition.

[0039] The compositions of the present invention are preferred in which the copper(II) ions comprise at least 95 mol-%, more preferably at least 98 mol-%, even more preferably at least 99 mol-%, and most preferably 99.9 mol-% of all precipitable metal cations in the composition. A "precipitable metal cation" is a cation that precipitates in metallic form along with copper upon application of an electric current. Examples of such "precipitable metal cations" include tin, nickel, and silver.

[0040] Preferred compositions of the present invention are those in which the copper(II) ions in the composition account for at least 95 mol-%, more preferably at least 98 mol-%, even more preferably at least 99 mol-%, and most preferably at least 99.9 mol-% of all transition metal cations in the composition.More preferred compositions of the present invention are those in which the copper(II) ions in the composition, together with the metal ions of the main groups III, IV, and V of the periodic table, account for at least 95 mol-%, more preferably at least 98 mol-%, even more preferably at least 99 mol-%, and most preferably at least 99.9 mol-% of all transition metal cations in the composition.

[0041] Preferably, the acidic aqueous composition of the present invention is not for copper alloys.

[0042] Most preferred are compositions of the present invention in which the copper(II) ions are the only precipitable metal cation. Therefore, the electroplated copper in the method of the present invention is most preferably pure copper. In the context of the present invention, "pure copper" means that the electroplated copper contains at least 99.5 wt.-% copper, based on the total weight of the electroplated copper.

[0043] Preferred are compositions of the present invention in which the composition is substantially free (preferably free) of transition metals other than copper. Also preferred are compositions in which the composition is substantially free (preferably free) of aluminum, gallium, indium, tin, and lead (preferably in addition to the aforementioned).

[0044] In the context of the present invention, the term "substantially free" of an object (e.g., a compound, metal ion, etc.) means that the object is not present at all or is present only in a very small, inconspicuous amount (to the extent that it does not affect the intended purpose of the present invention). For example, such an object may be unintentionally added or utilized, for example, as an unavoidable impurity. When defined with respect to the composition of the present invention, "substantially free" preferably represents 0 (zero) ppm to 50 ppm, preferably 0 ppm to 25 ppm, more preferably 0 ppm to 10 ppm, even more preferably 0 ppm to 5 ppm, and most preferably 0 ppm to 1 ppm, relative to the total mass of the composition, or when defined with respect to the electrolytically plated copper obtained by the method of the present invention, relative to the total mass of the plated copper.

[0045] The acidic aqueous composition for electrolytic copper plating according to the present invention (as defined above, preferably as preferred) comprises one or more suppressors (ii) (at least one or more suppressors (ii) as defined above and below, preferably as preferred). In some cases, it is preferred that the acidic aqueous composition for electrolytic copper plating according to the present invention (as defined above, preferably as preferred) comprises only one suppressor (ii) (one suppressor (ii) as defined above and below, preferably as preferred). Without being bound by theory, it is believed that the suppressor (ii) of the present invention combines the beneficial features of different known suppressors and levelers. By using the suppressor (ii) of the present invention, no additional suppressor (iii) and / or leveler is required, or at least the concentration of the additional suppressor and / or leveler can be very low.

[0046] Throughout this text, the word "independently" (e.g., in the terms "independently selected" or "independently represent") is used in reference to moieties and groups. The meaning of this word is illustrated by the following example: For example compound X having example groups E, F, and G, "E, F, and G are independently selected from the group consisting of [...]" This means that (i) example group F in example compound X is independently selected from example groups E and G in example compound X, and (ii) example group F in example compound X is independently selected from other example groups F in other example compounds, such as example compound Y.

[0047] Throughout this text, the term "alkyl" is used to refer to a univalent radical derived from an alkane by removal of a hydrogen atom from any carbon atom (C n H 2n+1 For example, the term "C3-C16 alkyl" refers to an alkyl group having 3 to 16 carbon atoms (n=3-16). Throughout this document, C3 alkyl explicitly includes n-propyl and isopropyl, C4 alkyl explicitly includes n-butyl, isobutyl, sec-butyl, tert-butyl, and C5 alkyl explicitly includes

[0048] [ka]

[0049] where the dashed lines represent the covalent bonds (connecting bonds) connecting each carbon atom of the alkyl group to each atom of the molecule.

[0050] Throughout the text, the term "polypropylene" is used to refer to polypropylene which may be based on n-propyl or isopropyl units.

[0051] Preferably, in the acidic aqueous composition for electrolytic copper plating according to the present invention (as defined above, preferably as preferred), the total amount of component (ii) (the total amount of one suppressor (ii), or, if more than one suppressor (ii) is present, the total amount of all suppressors (ii)) is at least 10 mg / L, preferably at least 50 mg / L, more preferably at least 70 mg / L, and even more preferably at least 80 mg / L, relative to the total volume of the acidic aqueous composition. Preferably, the total amount does not exceed 1 g / L, preferably does not exceed 700 mg / L, more preferably does not exceed 500 mg / L, relative to the total volume of the acidic aqueous composition. Preferred are acidic aqueous compositions for electrolytic copper plating according to the present invention, in which one or more suppressors (ii) are present in a total amount in the range of 10 mg / L to 1000 mg / L, preferably in the range of 50 mg / L to 700 mg / L, more preferably in the range of 70 mg / L to 500 mg / L, and most preferably in the range of 80 mg / L to 400 mg / L, relative to the total volume of the acidic aqueous composition.

[0052] Preferably, the acidic aqueous composition for electrolytic copper plating according to the present invention (as defined above, preferably as preferred) comprises: (iii) at least one additional inhibitor different from inhibitor (ii); and / or (iv) at least one accelerator different from the inhibitors (ii) and (iii); Includes.

[0053] Preferably, the acidic aqueous composition for electrolytic copper plating according to the present invention (as defined above, preferably as preferred) comprises one, two, three or more further compounds, which are different from the suppressor (ii), the additional suppressor (iii) or the accelerator (iv). Preferably, the one, two, three or more further compounds are selected from the group consisting of one or more inorganic ions, one or more leveller compounds, and one or more wetting agents.

[0054] Preferably, the compositions of the present invention are substantially free, preferably free, of complexing agents.

[0055] Preferred types of inorganic ions are selected from the group consisting of halide ions (preferably chloride ions) and sulfate ions. They may be added completely or partially to the acidic aqueous composition according to the invention by a copper source (see the text above for various copper sources). Other suitable sources of halide ions are, for example, hydrochloric acid or alkali halides, such as sodium chloride.

[0056] Preferred are compositions of the present invention, wherein one, two, three or more further compounds comprise halide ions, preferably chloride ions.

[0057] Preferably, in the acidic aqueous composition for electrolytic copper plating according to the present invention (as defined above, preferably as preferred), the total amount of chloride ions is in the range of 0.01 to 0.18 g / L, preferably 0.03 to 0.10 g / L, based on the total volume of the acidic aqueous composition. Preferably, the total amount of hydrochloric acid is in the range of 0.01 to 0.18 g / L, preferably 0.03 to 0.10 g / L, based on the total volume of the acidic aqueous composition.

[0058] In a preferred embodiment of the present invention, the suppressor (II) does not contain a halide as a negatively charged counter group, so that additional halide ions, particularly chloride ions, are not added to the acidic aqueous composition for electrolytic copper plating.

[0059] The acidic aqueous composition for electrolytic copper plating according to the present invention (as defined above, preferably as preferred) preferably contains sulfuric acid. Preferably, the total amount of sulfuric acid added to prepare the composition according to the present invention is in the range of 5 g / L to 350 g / L, preferably 5 g / L to 220 g / L, based on the total volume of the acidic aqueous composition. A total amount in the range of 5 g / L to 140 g / L or 180 g / L to 220 g / L is more preferred. Sulfuric acid can also be partially or completely replaced with fluoroboric acid, methanesulfonic acid, or other acids.

[0060] In some cases, it is preferred that the acidic aqueous composition according to the present invention comprises a redox couple, more preferably Fe(II) / Fe(III) ions. Such a redox couple is particularly useful when reverse pulse plating is used in combination with an inert anode for copper deposition. Suitable methods for copper plating using a redox couple in combination with reverse pulse plating and an inert anode are disclosed, for example, in US Pat. No. 5,976,341 and US Pat. No. 6,099,711.

[0061] The at least one accelerator (iv) is preferably selected from the group consisting of thiol, sulfide, disulfide and polysulfide compounds. More preferred accelerators are 3-(benzothiazolyl-2-thio)-propylsulfonic acid, 3-mercaptopropane-1-sulfonic acid, ethylenedithiodipropylsulfonic acid, bis-(p-sulfophenyl)-disulfide, bis-(ω-sulfobutyl)-disulfide, bis-(ω-sulfohydroxypropyl)-disulfide, bis-(sodium sulfopropyl)-disulfide, bis-(ω-sulfopropyl)-disulfide, bis-(ω-sulfopropyl)-disulfide, methyl-(ω- The accelerator is selected from the group consisting of methyl (ω-sulfopropyl)-disulfide, methyl (ω-sulfopropyl)-trisulfide, O-ethyl-dithiocarbonic acid S-(ω-sulfopropyl)ester, thioglycolic acid, thiophosphoric acid O-ethyl-bis-(ω-sulfopropyl)ester, 3-N,N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid, 3,3'-thiobis(1-propanesulfonic acid), thiophosphoric acid tris-(ω-sulfopropyl)ester, and the corresponding salts thereof. The total amount of the accelerator is preferably in the range of 0.001 g / L to 0.5 g / L, more preferably in the range of 0.005 g / L to 0.2 g / L, and even more preferably in the range of 0.01 g / L to 0.100 g / L, based on the total volume of the acidic aqueous composition.

[0062] The at least one additional inhibitor (iii) is preferably selected from the group consisting of polyvinyl alcohol, carboxymethylcellulose, polyethylene glycol, polypropylene glycol, stearic acid polyglycol esters, alkoxylated naphthols, oleic acid polyglycol esters, stearyl alcohol polyglycol ethers, nonylphenol polyglycol ethers, octanol polyalkylene glycol ethers, octanediol-bis-(polyalkylene glycol ethers), poly(ethylene glycol-ran-propylene glycol), poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol), and poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol). More preferably, the additional inhibitor is selected from the group consisting of polyethylene glycol, polypropylene glycol, poly(ethylene glycol-ran-propylene glycol), poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol), and poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol). The total amount of additional inhibitor compounds is preferably in the range of 0.005 g / L to 20 g / L, more preferably in the range of 0.01 g / L to 5 g / L.

[0063] Own reference experiments have shown that acidic aqueous reference compositions (not according to the present invention; i.e., not containing inhibitor (ii) but containing additional inhibitor (iii) (e.g., as defined above)) also often result in smoother and more uniform copper surfaces compared to copper surfaces obtained in the absence of such additional inhibitor (iii). Furthermore, many of the aforementioned compounds also typically contribute to the appropriate overpotential in the respective reference compositions. However, the overpotential obtained in such reference compositions is usually significantly lower compared to acidic aqueous compositions according to the present invention.

[0064] Thus, in some cases, the acidic aqueous composition according to the present invention is substantially free, preferably free, of one or more additional inhibitors (iii) selected from the group consisting of polyvinyl alcohol, carboxymethylcellulose, polyethylene glycol, polypropylene glycol, stearic acid polyglycol esters, alkoxylated naphthols, oleic acid polyglycol esters, stearyl alcohol polyglycol ethers, nonylphenol polyglycol ethers, octanol polyalkylene glycol ethers, octanediol-bis-(polyalkylene glycol ethers), poly(ethylene glycol-ran-propylene glycol), poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol), and poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol). However, in other cases, it appears acceptable to additionally include one or more additional inhibitors as defined above. Our own experiments have shown that in many cases, the relatively high overvoltages generated in the acidic aqueous composition according to the present invention are not adversely affected by the presence of additional inhibitors as defined above.

[0065] In addition, optionally, at least one leveler compound can be used. Preferred levelers are selected from the group consisting of nitrogen-containing leveler compounds, such as polyethyleneimine, alkoxylated polyethyleneimine, alkoxylated lactams and their polymers, diethylenetriamine and hexamethylenetetramine, dyes such as Janus Green B, Bismarck Brown Y, and Acid Violet 7, sulfur-containing amino acids, such as cysteine, and phenazinium salts. Further nitrogen-containing levelers can be polyethyleneimine-containing peptides, polyethyleneimine-containing amino acids, polyvinyl alcohol-containing peptides, polyvinyl alcohol-containing amino acids, polyalkylene glycol-containing peptides, polyalkylene glycol-containing amino acids, aminoalkylene-containing pyrroles, and aminoalkylene-containing pyridines. Suitable ureylene polymers are disclosed in EP 2735627 A1 and EP 2922985 A1, and the polyalkylene glycol-containing amino acids and peptides are published in EP 2113587 B9. EP 3497267 discloses end-capped polyether compounds. EP 2537962 A1 teaches suitable aminoalkylene compounds containing pyrrole and pyridine. WO2016169952A1 teaches suitable capped guanidine compounds. The total amount of leveler compounds in the acidic aqueous composition according to the present invention is preferably in the range of 0.1 mg / L to 100 mg / L based on the total volume of the composition. Our experiments have shown that such leveler compounds often improve the stability of the process.

[0066] Our own experiments have shown that in a few cases, some leveler compounds as defined above have a slightly negative (but still tolerable) effect on the overvoltage generated in the acidic aqueous composition according to the present invention. Therefore, in a few cases, the acidic aqueous composition according to the present invention (as defined above, preferably as preferred) is substantially free, preferably does not contain, one or more leveler compounds as defined above. In one embodiment of the acidic aqueous composition according to the present invention, it is preferred that the leveler is not polyethyleneimine (PEI).

[0067] Preferably, the acidic aqueous composition according to the present invention contains at least one wetting agent. These wetting agents are also referred to in the art as surfactants. The at least one wetting agent is preferably selected from the group consisting of nonionic, cationic, and anionic surfactants. The total amount of wetting agent in the acidic aqueous composition according to the present invention is preferably in the range of 0.01 to 5 wt. % based on the total weight of the acidic aqueous composition.

[0068] As noted above, the acidic aqueous compositions according to the present invention contain one or more inhibitors (ii) consisting of or comprising one single N-heteroaromatic monocyclic ring, the monocyclic ring containing at least two ring nitrogen atoms and more than one substituent covalently bonded to one of the ring nitrogen atoms and / or ring carbon atoms, the substituents being independently - one or more than one linear or branched polyalkylene glycol moiety, and / or - being or comprising one or more linear or branched polyalkylene glycol, block polyalkylene glycol or random polyalkylene glycol moieties;

[0069] Preferably, in the acidic aqueous composition according to the invention, the one or more linear or branched polyalkylene glycol moieties independently comprise a polyethylene glycol moiety and / or a polypropylene glycol moiety, wherein the polypropylene may be based on n-propyl or isopropyl units, preferably a polyethylene glycol moiety.

[0070] Preferred are acidic aqueous compositions according to the present invention, wherein the one or more linear or branched polyalkylene glycol-block polyalkylene glycol moieties independently comprise polyethylene glycol-block-polypropylene glycol moieties and / or polypropylene glycol-block-polyethylene glycol moieties, preferably polyethylene glycol-block-polypropylene glycol moieties, or the one or more linear or branched random polyalkylene glycol moieties independently comprise random polyethylene glycol-polypropylene glycol moieties, wherein the polypropylene may be based on n-propyl or isopropyl units.

[0071] Preferably, in the acidic aqueous composition according to the invention, the one or more inhibitors (ii) contain a total of 1 to 4, preferably 2 to 3, most preferably 3 aromatic ring carbon atoms.

[0072] Preferably, in the acidic aqueous composition according to the invention, one single N-heteroaromatic monocycle is a 6-membered or 5-membered ring, preferably a 5-membered ring.

[0073] According to the present invention, it is preferred that one single N-heteroaromatic monocycle does not contain a ring oxygen atom.Preference is given to acidic aqueous compositions according to the present invention, in which the one or more inhibitors (ii) consist of carbon, hydrogen, nitrogen and oxygen atoms.

[0074] Preferred is an acidic aqueous composition according to the present invention, wherein one single N-heteroaromatic monocyclic ring is selected from the group consisting of a pyrazole ring, an imidazole ring, a 1,3,5-triazine ring, a 1,2,4-triazine ring, a 1,2,3-triazine ring, and a tetrazole ring, preferably selected from the group consisting of an imidazole ring and a 1,3,5-triazine ring, and most preferably an imidazole ring.

[0075] Preferred are acidic aqueous compositions according to the invention, wherein in one or more inhibitors (ii), one of the substituents is covalently bonded to one of the at least two ring nitrogen atoms such that the nitrogen atom is positively charged.

[0076] Preferably, in the acidic aqueous composition according to the present invention, each of the one or more linear or branched polyalkylene glycol moieties and each of the one or more polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moieties each contains a terminal alkyl group, preferably a C1-C4 alkyl group, most preferably a methyl group.

[0077] Preferred are acidic aqueous compositions according to the present invention, wherein the one or more inhibitors (ii) do not contain any aromatic ring structures except for one single N-heteroaromatic monocyclic ring, preferably do not contain any ring structures except for one single N-heteroaromatic monocyclic ring.

[0078] Our own experiments have shown that one or more inhibitors (ii)

[0079] [ka]

[0080] (wherein, independently, R represents a linear or branched polyalkylene glycol moiety, a linear or branched polyalkylene glycol block polyalkylene glycol moiety or a random polyalkylene glycol (as defined above, preferably as preferred), and R 1 is alkyl, preferably alkyl is methyl, ethyl or propyl, most preferably methyl; - n represents 0, 1, 2, 3, 4 or 5, preferably 0, 1, 2 or 3 Excellent results were obtained when the compound was selected from the group consisting of:

[0081] Therefore, the use of compounds (Ia), (Ib), (Ic), (Id), (Ie) and / or (If) as inhibitors (ii) in the acidic aqueous compositions according to the invention is preferred, in particular the use of compounds (Ia), (Ib), (Ic) and / or (If) which contain a positively charged nitrogen.

[0082] one or more inhibitors (ii)

[0083] [ka] [ka]

[0084] (wherein, independently, a represents an integer ranging from 2 to 22, preferably from 3 to 20, and most preferably from 4 to 16; - b represents an integer ranging from 2 to 22, preferably from 3 to 20, and most preferably from 4 to 16. Further preferred are acidic aqueous compositions according to the present invention selected from the group consisting of: Accordingly, the respective acidic aqueous compositions for electrolytic copper plating according to the present invention (as defined above, preferably as preferred) are particularly preferred. These are highly preferred specific suppressors (ii), thus resulting in highly preferred compositions according to the present invention comprising one or more suppressors (ii).

[0085] Our own experiments have shown that these compounds have shown very good plating results and sufficiently high overpotentials compared to PEG for acidic aqueous compositions for electrolytic metal plating, preferably for electrolytic copper plating, and more preferably for the compositions and methods, respectively, as defined in accordance with the present invention.

[0086] Preferably, in the acidic aqueous composition according to the present invention, the weight average molecular weight (Mw) of the inhibitor (ii) is in the range of 500 g / mol to 5,000 g / mol, preferably in the range of 600 g / mol to 4,000 g / mol, preferably in the range of 700 g / mol to 3,000 g / mol, as measured by gel permeation chromatography (GPC) using a calibration curve based on polystyrene standards.

[0087] The present invention also relates to the use of the acidic aqueous composition according to the invention (as defined above, preferably as preferred) for electrolytic copper plating, preferably for void-free copper filling of recessed structures, preferably recessed structures with an aspect ratio in the range of 1:20 to 20:1. Preferred recessed structures are trenches, blind microvias, and through-holes.

[0088] Preferred are acidic aqueous compositions according to the invention, in which at least one additional inhibitor (inhibitor (iii)) different from inhibitor (ii) is a polymer containing nitrogen and / or oxygen, preferably selected from the group consisting of polyvinyl alcohol, carboxymethylcellulose, polyethylene glycol, polypropylene glycol, stearic acid polyglycol esters, alkoxylated naphthols, oleic acid polyglycol esters, stearyl alcohol polyglycol ethers, nonylphenol polyglycol ethers, octanol polyalkylene glycol ethers, octanediol-bis-(polyalkylene glycol ethers), poly(ethylene glycol-ran-propylene glycol), poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol), poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol), and poly(ethylene oxide)-poly(propylene oxide) (PEO-PPO) blocks attached to a central ethylenediamine moiety, also called poloxamine.

[0089] The concentration of said optional additional inhibitor (iii) is preferably in the range of 0.0005 g / L to 1 g / L, more preferably 0.001 g / L to 0.5 g / L.

[0090] The above-mentioned features relating to the acidic aqueous composition according to the invention (preferably those defined as preferred) also apply to the use of the acidic aqueous composition for electrolytic copper plating and void-free copper filling.

[0091] The present invention also relates to the use of a suppressor (ii) as defined in the text above in an acidic aqueous composition for electrolytic metal plating, preferably in an acidic aqueous composition for electrolytic copper plating, preferably in an acidic aqueous composition for electrolytic copper plating according to the invention (as defined above, preferably as preferred).

[0092] The above features relating to the acidic aqueous composition (as defined above, preferably as preferred) also apply to the aforementioned use of the acidic aqueous composition for electrolytic copper plating and to the aforementioned use of the compound.

[0093] The present invention further provides an inhibitor for electrolytically depositing copper deposits, comprising: - comprising, and preferably consisting of, one single N-heteroaromatic monocycle containing at least two ring nitrogen atoms and more than one substituent covalently bonded to one of said ring nitrogen atoms and / or to a ring carbon atom, said substituents being independently - one or more than one linear or branched polyalkylene glycol moiety, and / or - one or more than one linear or branched polyalkylene glycol, block polyalkylene glycol or random polyalkylene glycol moiety is or contains however, - when the inhibitor contains an OH group, it is a terminal OH group of each of the polyalkylene glycol moieties and the polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moieties; - the compound does not contain NH groups, halide atoms and sulfur atoms, Regarding inhibitors.

[0094] The inhibitor is

[0095] [ka] [ka]

[0096] (wherein, each independently a represents an integer ranging from 2 to 22, preferably from 3 to 20, and most preferably from 4 to 16; - b represents an integer ranging from 2 to 22, preferably from 3 to 20, and most preferably from 4 to 16. Preferably, the inhibitor according to the present invention is selected from the group consisting of:

[0097] In one embodiment of the present invention, if one single N-heteroaromatic monocycle is an imidazole ring, preferably if one or more of the linear or branched polyalkylene glycol moieties are not polyethylene glycol moieties, then it is preferred that one or more of the linear or branched polyalkylene glycol moieties are not polyethylene glycol moieties.

[0098] The above-mentioned features relating to the suppressor (ii) contained in the aqueous composition for electrolytic copper plating according to the present invention (as defined above, preferably as preferred) also apply to the aforementioned suppressor according to the present invention.

[0099] The use of compounds (IIa), (IIb), (IIb'), (Ic), (Id), (Ie) and / or (If) as inhibitors (ii) in the acidic aqueous compositions for copper plating according to the present invention is preferred, with inhibitors (IIb), (IIb'), (IId) and (IIe) being even more preferred, and most preferred being (IIb), (IIb') or (IIe).

[0100] The present invention further comprises: (a) providing or manufacturing a substrate suitable for electrolytic copper plating, preferably a substrate having a structured layer on its surface; (b) contacting the substrate obtained in step (a) or obtained in an additional step after step (a) but before step (b) with an acidic aqueous composition according to the invention (as defined above, preferably as preferred); applying a current so that copper is electrolytically plated (deposited) onto the substrate as a copper deposit; The present invention relates to an electrolytic copper plating method, comprising:

[0101] In the method according to the invention, the substrate and at least one anode are connected to a current source or a respective voltage source. When a current is applied, copper is plated (deposited) onto the substrate (at least a portion of the surface of the substrate). In some cases, step (b) is carried out immediately after step (a). In other cases, it is preferred to include a cleaning and / or rinsing step as an additional step after step (a). In such cases, a cleaned / rinsed substrate is obtained. Preferably, such a cleaned / rinsed substrate is directly contacted as defined in step (b).

[0102] Preferably, the substrate is selected from the group consisting of a printed circuit board, an IC substrate, a semiconductor wafer, a ceramic substrate, and a glass substrate. Substrates of the aforementioned group having recessed structures, such as trenches, blind microvias, through-silicon vias, through-holes, and through-glass vias, are preferred. Therefore, substrates containing one or more recessed structures selected from the group consisting of trenches, blind microvias, and through-holes are preferred. In the method of the present invention, these structures are preferably filled with copper without voids (see the "Examples" below). Therefore, a preferred method of the present invention is one in which, in step (b), copper is electroplated onto the substrate and a current is applied to fill the recessed structures, preferably trenches, blind microvias, and through-holes, without voids with copper. The method can also be used for substrates processed by a dual damascene process.

[0103] In many cases, it is preferred that the substrate contain a metal seed layer, more preferably a copper seed layer. In some cases, the substrate preferably comprises a resin, ceramic, glass, or silicon, more preferably with a metal seed layer, even more preferably a copper seed layer.

[0104] During the electrolytic copper plating method of the present invention, the acidic aqueous composition of the present invention is preferably agitated, more preferably by a strong inflow, and if applicable, by blown-in clean air, so that the surface of the composition is subjected to strong motion. This maximizes mass transport in the vicinity of the cathode and anode, allowing for greater current density. The movement of the cathode also improves mass transport at their respective surfaces. In addition, convection can be generated in the composition by rotating the substrate. A consistent diffusion-controlled deposition is achieved by increasing the convection and the movement of the electrodes. The substrate can be moved horizontally and vertically and / or by vibration. The combination of blown-in air into the composition is particularly effective and therefore preferred.

[0105] In the electrolytic copper plating method according to the present invention (as described above, preferably as preferred), step (b) is preferably carried out at a temperature in the range of 15° C. to 50° C., more preferably at a temperature in the range of 15° C. to 40° C. This means that in step (b), the composition of the present invention has a temperature as defined above.

[0106] Preferably, 0.05A / dm 2 ~12A / dm 2 range, more preferably 0.1A / dm 2 ~7A / dm 2 in the range of 0.1A / dm 2 ~3A / dm 2 However, current densities above the above range are not excluded, particularly for pulse plating processes.

[0107] Preferably, in the electrolytic copper plating method according to the present invention (as described above, preferably as preferred), step (b) is carried out in a DC plating mode (DC plating method), a pulse plating mode, including a reverse pulse plating mode (pulse plating method and reverse pulse plating method, respectively), or a combination thereof.

[0108] Pulse plating typically involves a unipolar pulsed current in which the deposition current is periodically interrupted by current pauses. Reverse pulse plating typically involves pulses of reverse current during the plating process.

[0109] Reverse pulse plating methods have been developed especially for the electrolytic deposition of copper onto high aspect ratio circuit boards and are described, for example, in DE 42 25 961 C2 and DE 2739427. When higher current densities are used, improved surface distribution and throwing power are achieved in the through-holes.

[0110] In the method of the present invention (as defined above, preferably as preferred), an inert (insoluble) or soluble anode is used. In some cases, an inert anode is preferred. An insoluble anode is inactive during the plating process and, as a result, its shape does not change. This allows for a constant shape over time during the plating process. In particular, precious metals, such as platinum, or so-called valve metals, such as titanium coated with a coating of mixed oxides of precious metals, e.g., ruthenium oxide and iridium oxide, are also preferably used as insoluble anodes in the method of the present invention. In some cases, it is preferred that the insoluble anode is in the form of expanded metal. To obtain a copper ion replenishment when using an insoluble anode, it is necessary to dissolve a copper compound in the acidic aqueous composition of the present invention (see the text above for copper sources) or to contact metallic copper with the composition. Metallic copper dissolves under the influence of oxygen dissolved in the composition or with the aid of a compound that forms an oxidized form of a redox system, for example, with the aid of Fe(III) ions that dissolve in the composition and are thereby reduced to Fe(II) ions. The Fe(II) ions are oxidized at the insoluble anode back to Fe(III) ions. The Fe(II) / Fe(III) ions can be derived, for example, from the corresponding iron sulfate salts. The concentration of the Fe(II) ions in the composition is preferably 8 to 12 g / L, and the concentration of the Fe(III) ions is preferably 1 to 5 g / L, based on the total volume of the composition.

[0111] However, in other cases, soluble copper anodes are preferred. Copper consumed during the deposition (plating) process is typically replenished electrochemically via soluble copper anodes. Soluble copper anodes with phosphorus contents of 0.02 to 0.067 weight percent are particularly preferred.

[0112] In the method according to the present invention, copper is preferably plated by both conventional methods: immersing a substrate in a composition located in an immersion bath vessel and polarizing the substrate against an anode located in the same composition, and by horizontal plating. The latter plating method is carried out in a conventional horizontal apparatus, through which the substrate is conveyed in a horizontal position in the transport direction and simultaneously contacted with the acidic aqueous composition. The anode is also arranged in a horizontal position within the apparatus along the transport path of the substrate. These types of apparatus are disclosed, for example, in DE 36 24 481 A1 and DE 32 36 545 A1. Additionally, semiconductor wafers are preferably processed in a so-called cup plater, in which each wafer is arranged in a horizontal position above an anode, which is also arranged in a horizontal position. The cup plater is filled with the acidic aqueous composition according to the present invention, so that both the wafer and the anode are in contact with the composition. Preferably, the wafer rotates during the deposition process.

[0113] Furthermore, the above features relating to the acidic aqueous composition (as defined above, preferably as preferred) preferably apply to the electrolytic copper plating method according to the present invention.

[0114] In a preferred method according to the present invention, the plated copper deposit forms a plurality of copper pillars and / or a plurality of copper conductive traces, preferably the copper deposit is a plurality of copper conductive traces, more preferably the copper deposit is a plurality of copper conductive traces in a redistribution layer. The plurality of copper pillars are preferably plated by so-called bottom-up plating of a recessed structure. The plurality of copper conductive traces as through holes are preferably plated / filled by so-called x-plating, in which the through holes are first plated in the center of the through holes, a blind via is created to close the hole, and then the created blind via is filled.

[0115] A method according to the invention is preferred, wherein the copper deposit deposited in step (b) has an aspect ratio in the range of 1:20 to 20:1.

[0116] A method according to the invention is preferred, wherein the copper deposit deposited in step (b) has a height in the range of 0.2 μm to 200 μm.

[0117] A method according to the invention is preferred, wherein the copper deposit deposited in step (b) has a width in the range of 0.2 μm to 200 μm.

[0118] Preferred is a method according to the present invention, wherein in step (b) direct current is applied, preferably at a current density in the range of 0.1 ASD to 120 ASD, most preferably only direct current is applied in step (b), preferably at a current density in the range of 0.2 ASD to 80 ASD.

[0119] A method according to the invention is preferred, wherein in step (b) a direct current is applied, preferably with a current density in the range of 0.1 ASD to 4 ASD.

[0120] Preferred is a method according to the invention, wherein in step (b) a direct current is applied, preferably with a current density in the range of 1 ASD to 10 ASD.

[0121] Preferred is a method according to the invention, wherein in step (b) a direct current is applied, preferably at a current density in the range of 10 ASD to 80 ASD.

[0122] The following examples illustrate the advantages of the present invention. [Example]

[0123] A. Synthesis: A1. Synthesis of compounds of formula (IIb): In the first step, polyethylene glycol (PEG, Alfa Aesar, Mw = 202 g / mol) was reacted by nucleophilic substitution with paratoluenesulfonyl chloride (p-TsCl, Merck, 98%) in tetrahydrofuran (THF, VWR, 100%) / water in the presence of NaOH at 0 °C for 20 h to give tosylated polyethylene glycol ((bis-Ts)-PEG, yield: approximately 70%), which was further purified in the subsequent steps.

[0124] In the second step, (bis-Ts)-PEG was reacted by nucleophilic substitution with polypropylene glycol monomethyl ether (PPG206, M = 206 g / mol, 3 monomer units) in the presence of potassium tert-butoxide (KO-t-butyl, Merck, 98%) in THF at 50 °C for 20 h to give tosylated polyethylene glycol-block-polypropylene glycol methyl ester (block intermediate, yield: approximately 15%).

[0125] In the third step, the blocked intermediate was reacted with imidazole (Merck, 100%) by nucleophilic substitution in the presence of KO-t-butyl in THF at 65°C for 165 hours to give the compound of formula (IIb) (yield: approximately 25%, Mw = 797). In the subsequent step, the compound was further purified by HPLC (ACN / HO: 30 / 70 vol-%; yield: approximately 10%).

[0126] A2. Synthesis of compounds of formula (IIc): In the first step, polyethylene glycol monomethyl ether (PEGMe, Alfa Aesar, Mw = 350 g / mol) was reacted with trichlorotriazine (Acros Organics, 99%) in the presence of KO-t-butyl ether in THF at temperatures ranging from 0 °C to 60 °C for 20 h to give the compound of formula (IIc) (yield: approximately 23%, Mw = 963 g / mol). In a different approach, PEGMe with Mw = 750 g / mol was utilized instead of PEGMe with Mw = 350 g / mol. As a result, the compound of formula (IIc) with Mw = 2152 g / mol was obtained.

[0127] B. Precipitation results: B1. (Example 1): Acidic aqueous composition (according to the invention): In the first step, (i) a total of 60 g / L of copper ions (added as copper(II) sulfate pentahydrate, CuSO4 * A plating bath was prepared by mixing (IIb) 5H2O (also used in the following examples), (ii) a total amount of 0.010 g / L of the compound of Formula (IIb), (iii) a total amount of 50 g / L of sulfuric acid, (iv) a total amount of 0.030 g / L of chloride ions (added as HCl), (v) a total amount of 3 mL / L of disulfide as an accelerator (Spherolyte® Acc 10), and (vi) deionized water.

[0128] In the second step, electrolytic copper plating was carried out using the acidic composition prepared in the first step. The plating bath temperature was 25°C and the current density was 2 mA / cm. 2 was applied for 50 minutes. A copper layer was electroplated onto the prepared wafer substrate with a copper seed layer and a characteristic diameter of 10 μm with an aspect ratio of approximately 6:1.

[0129] The vias were completely filled without any defects such as voids. The fill height was 68.2 μm. A photograph of the cross section of the copper metallized wafer substrate is shown in Figure 1.

[0130] B.2. (Example 2): Acidic aqueous composition (comparative example, not according to the invention): Example 1 was repeated, but in the acidic aqueous comparative composition according to Example 2 (not according to the invention), Tetronic® 304 (poly(ethylene oxide)-poly(propylene oxide) (PEO-PPO) blocks attached to a central ethylenediamine moiety) was used instead of the compound of formula (IIb). Tetronic® 304 is a common additive in the respective compositions, is commercially available, and is described in more detail in paragraph

[0027] of International Patent Application WO2008157612A1.

[0131] In a first step, a comparative composition was prepared by mixing (i) 60 g / L total copper ions, (ii) 0.01 g / L total Tetronic® 304, (iii) 50 g / L total sulfuric acid, (iv) 0.030 g / L total chloride ions (added as HCl), (v) 3 mL / L total disulfide accelerator (Spherolyte® Acc 10), and (vi) deionized water.

[0132] In the second step, electrolytic copper plating was carried out using the acidic composition prepared in the first step. The plating bath temperature was 25°C and the current density was 2 mA / cm. 2 was applied for 50 minutes. A copper layer was electroplated onto the prepared wafer substrate with a copper seed layer and a characteristic diameter of 10 μm with an aspect ratio of approximately 6:1.

[0133] The vias were incompletely filled without any defects as voids (dimples). The fill height was 60 μm. A photograph of the cross section of the copper metallized wafer substrate is shown in Figure 2.

Claims

1. 1. An acidic aqueous composition for electrolytically depositing a copper deposit, comprising: (i) copper(II) ions; (ii) one or more inhibitors, a single N-heteroaromatic monocycle containing at least two ring nitrogen atoms and more than one substituent covalently bonded to one of said ring nitrogen atoms and / or to a ring carbon atom, said substituents being independently one or more linear or branched polyalkylene glycol moieties, and / or being or comprising one or more linear or branched polyalkylene glycol, block polyalkylene glycol or random polyalkylene glycol moieties; however, When the inhibitor contains an OH group, it is a terminal OH group of the polyalkylene glycol moiety, polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moiety, The inhibitor is NH 2 does not contain groups, halogen atoms, or sulfur atoms; an inhibitor, (ii) said one or more inhibitors 【Chemistry 1】 (wherein, independently, R represents a linear or branched polyalkylene glycol moiety, or a linear or branched polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moiety; 1 is alkyl, n represents 0, 1, 2, 3, 4, or 5) is selected from the group consisting of (ii) The acidic aqueous composition, wherein the inhibitor has a weight average molecular weight (Mw) in the range of 500 g / mol to 5000 g / mol.

2. (iii) at least one additional inhibitor different from inhibitor (ii); and (iv) at least one accelerator different from the inhibitors (ii) and (iii); 10. The composition of claim 1, further comprising:

3. 3. The composition of claim 2, wherein the at least one additional inhibitor different from inhibitor (ii) is a polymer containing nitrogen and / or oxygen atoms.

4. (ii) said one or more inhibitors 【Chemistry 2】 【Transformation 3】 (wherein, independently, a represents an integer ranging from 2 to 22; b represents an integer ranging from 2 to 22) 4. The composition of claim 1, selected from the group consisting of:

5. 5. The composition of any one of claims 1 to 4, wherein the one or more inhibitors in (ii) are present in a total amount ranging from 10 mg / L to 1000 mg / L, relative to the total volume of the acidic aqueous composition.

6. (a) providing or manufacturing a substrate suitable for electrolytic copper plating; (b) contacting the substrate obtained after step (a), or obtained after an additional step after step (a) but before step (b), with the acidic aqueous composition of any one of claims 1 to 5, and applying an electric current such that copper is electrolytically plated as a copper deposit onto the substrate. Electrolytic copper plating method comprising:

7. The method of claim 6 , wherein the copper deposits form a plurality of copper pillars and / or a plurality of copper conductive traces.

8. 8. The method of claim 6 or 7, wherein the substrate comprises one or more recessed structures selected from the group consisting of trenches, blind microvias, and through-holes.

9. 1. An inhibitor for electrolytic deposition of copper deposits, comprising: a single N-heteroaromatic monocycle containing at least two ring nitrogen atoms and more than one substituent covalently bonded to one of said ring nitrogen atoms and / or to a ring carbon atom, said substituents being independently one or more linear or branched polyalkylene glycol moieties, and / or one or more linear or branched polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moieties is or contains however, When the inhibitor contains an OH group, it is a terminal OH group of each of the polyalkylene glycol portion, the polyalkylene glycol block polyalkylene glycol portion, and the random polyalkylene glycol portion; The inhibitor is NH 2 does not contain groups, halide atoms, or sulfur atoms; 【Chemistry 4】 (wherein, independently, R represents a linear or branched polyalkylene glycol moiety, or a linear or branched polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moiety; 1 is alkyl, n represents 0, 1, 2, 3, 4, or 5) is selected from the group consisting of having a weight average molecular weight (Mw) in the range of 500 g / mol to 5000 g / mol; Inhibitor. 【Request Item 10】 【Chemistry 5】 【Transformation 6】 (wherein, independently, a represents an integer ranging from 2 to 22; b represents an integer ranging from 2 to 22) 10. The inhibitor of claim 9, selected from the group consisting of:

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