Acidic aqueous composition for electrolytic deposition of copper deposits

Abstract

The invention relates to an acidic aqueous composition for electrolytic copper electroplating, said composition comprising: (i) copper (II) ions, (ii) one or more than one suppressor consisting of or comprising one single N-heteroaromatic monocyclic ring, said monocyclic ring comprising at least two ring nitrogen atoms and more than one substituent covalently linked to one of said ring nitrogen atoms and / or to a ring carbon atom, wherein said substituent is or comprises 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, with the proviso that if said suppressor comprises an OH group, it is a terminal OH group of said polyalkylene glycol moiety, polyalkylene glycol block polyalkylene glycol and random polyalkylene glycol moiety, respectively, and said suppressor does not comprise an NH2 group, a halogen atom and a sulfur atom; a method for electrolytic copper electroplating using said acidic aqueous composition; and specific suppressors as defined above.

Description

Technical Field

[0001] The present invention relates to an acidic aqueous composition (electroplating bath) for electrolytic copper plating (electrolytic copper deposition), the composition comprising copper (II) ions, one or more inhibitors having the definitions given below, a method for electrolytic copper plating using the acidic aqueous composition according to the invention, and specific inhibitors as defined above for electrolytically deposited copper deposits.

[0002] The acidic aqueous composition according to the invention is suitable for electrolytic deposition of copper, particularly for filling blind vias (BMVs), through-holes, trenches, and similar structures. Therefore, the method of the invention is suitable for manufacturing printed circuit boards (PCBs), integrated circuit (IC) substrates, and the like, as well as for metallizing semiconductors and glass substrates. Background Technology

[0003] Acidic aqueous compositions (aqueous acidic plating baths) for electrolytic copper plating (electrolytic copper deposition) are used to manufacture printed circuit boards (PCBs) and IC substrates that require copper filling or deposition of fine structures such as trenches, through-holes (TH), micro-blind vias (BMV), pillars, and bumps. Another application of these compositions is filling recessed structures (such as through-silicon vias (TSV) and dual damascene (DD) structures or features), plating or forming redistribution layers (RDLs), and pillars and bumps.

[0004] As printed circuit boards (PCBs) become increasingly miniaturized, their design and complexity continue to increase. Typically, the goal is to maximize computing power and / or functionality within a shrinking space. Consequently, the geometry of PCBs, or the conductor structures, chip carriers, and semiconductor wafers on PCBs, becomes 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), increases as hole diameters become smaller and conductor paths narrower.

[0005] Structures exhibiting relatively high aspect ratios (e.g., 6:1 to 3:1) are generally considered to require complex electrolytic copper plating methods because these structures exhibit variable electrodeposition behavior. Specifically, our own experiments have shown that forming uniform and reliable conductive structures in trenches and vias on printed circuit boards using methods known in the art are often insufficient and frequently very difficult. For example, due to the relatively increased aspect ratio of the structure (and therefore, variable electrodeposition behavior), copper layers with non-uniform surfaces are often formed during copper deposition. However, non-uniform surfaces often pose additional challenges during chemical / mechanical polishing after copper deposition. Typically, a prerequisite for individual polishing steps is that the copper surface produced during the electrolytic deposition process is sufficiently smooth and uniform to allow for reliable removal of metal up to the desired depth. Furthermore, a smooth and uniform surface contributes to improved reproducibility.

[0006] It is well known that a variety of different organic additives are added to aqueous compositions used for electrolytic copper plating to control the decorative and functional properties of copper coatings.

[0007] So-called “inhibitors” can be used, which “are typically polymeric organic species, such as high molecular weight polyethylene or polypropylene glycol, which strongly adsorb onto the surface of the copper cathode to form a film, thereby dramatically increasing the overpotential for copper deposition. This prevents uncontrolled copper plating [...]” (see US 2005 / 0247577 A1, paragraph

[0007] ). Additionally, anti-inhibitors (also known as “accelerators”) can be used to “counteract the inhibitory effect of the inhibitors and provide accelerated deposition within the desired substrate recesses” (see again US 2005 / 0247577 A1, paragraph

[0007] ).

[0008] To obtain a properly copper-filled structure, another organic additive can typically be used as a “leveling agent.” A “leveling agent” is “typically a nitrogen-containing organic compound that tends to reduce the rate of copper plating” (see US 2005 / 0247577 A1, paragraph

[0009] ).

[0009] JP 2013 023693 A discloses a copper electroplating bath comprising an alkene oxide compound with a terminal imidazole ring. The compound is believed to have good solubility in water and provide high defoaming properties in the electroplating bath.

[0010] During the electroplating process, the additives mentioned above typically have a positive effect on the uniform deposition and metallization of copper. It has been shown that in very small structures to be completely filled by copper, these additives often help to prevent the formation of hollow spaces (voids) in the copper deposit.

[0011] Unfortunately, in some cases, organic additives co-deposit with metal ions (e.g., copper ions), presumably leading to undesirable effects such as increased electromigration and reliability issues. It is generally assumed that if the additives have very strong adhesion to the electroplated surface, then the co-deposition of these additives will increase. Therefore, additives exhibiting appropriate adhesion properties are needed.

[0012] Furthermore, it is generally assumed that the quality of copper filling in structures exhibiting relatively high aspect ratios (e.g., 6:1 to 3:1) is related to the overpotential generated in the individual acidic aqueous compositions used for electrolytic copper plating (Journal of the Electrochemical Society 2004, 151, C702-C711).

[0013] There is a continued need for novel and improved acidic aqueous compositions for electrolytic copper plating (and certain plating methods) to obtain uniform and void-free copper deposits, wherein the deposits contain relatively small amounts of organic additives. Furthermore, individual compositions should exhibit sufficient stability (shelf life).

[0014] EP 2 778 260 A2 discloses a method for filling vias. The method disclosed herein suppresses or reduces pitting and voids during copper plating of vias having a flash copper layer in a substrate (e.g., a printed circuit board). EP 2 778 260 A2 discloses an aqueous acid solution substantially composed of one or more inorganic acids and one or more aromatic heterocyclic nitrogen compounds reacting with one or more epoxy-containing compounds, wherein the amount of said one or more reaction products is from 1 ppm to 50 ppm.

[0015] US 4,009,087 A relates to a process and novel compositions for electrodepositing copper from an aqueous acidic copper plating bath. The bath contains at least one member independently selected from each of the following two groups: (i) N-heteroaromatic compounds containing one or two N-heteroaromatic rings, and sulfonyl alkyl sulfides and sulfonyl aryl sulfides.

[0016] Objective of the present invention

[0017] The objective of this invention is to provide an acidic aqueous composition (electroplating bath) for electrolytic copper plating (electrolytic copper deposition), which exhibits good plating quality during the electrolytic plating process (i.e., substantially free of voids and achieving uniform copper deposition), particularly for substrates with structures exhibiting both low and high aspect ratios.

[0018] Another objective is to provide acidic aqueous compositions that exhibit increased overpotential compared to compositions that typically contain polyethylene glycol (PEG) as an inhibitory additive.

[0019] Furthermore, these compositions are expected to exhibit sufficient stability (storage life) and result in copper deposits containing relatively small amounts of organic additives, that is, sufficient adhesion to the copper surface.

[0020] Furthermore, the objective of this invention is to provide individual methods for electrolytic copper plating (electrolytic copper deposition) that, on the one hand, allow for relatively rapid copper filling to exhibit low and high aspect ratio structures, and on the other hand, provide sufficient plating quality (e.g., good surface distribution across the entire substrate and less co-deposition of organic additives). Summary of the Invention

[0021] The aforementioned objective is achieved through an acidic aqueous composition for electrolytic copper plating and an inhibitor for electrolytically deposited copper deposits, as described below, wherein the composition comprises:

[0022] (i) Copper(II) ions,

[0023] (ii) One or more inhibitors comprising or containing the following:

[0024] - A single N-heteroaromatic monocycle, the monocycle comprising at least two cyclic nitrogen atoms and more than one substituent covalently attached to one and / or one cyclic carbon atom of the cyclic nitrogen atoms, wherein the substituent is independently or comprises:

[0025] - One or more straight-chain or branched polyalkylene glycol moieties

[0026] and / or

[0027] - One or more linear or branched polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moieties, provided that

[0028] -If the inhibitor contains OH groups, then these are terminal OH groups of the polyalkylene glycol moiety, the polyalkylene glycol block polyalkylene glycol moiety, or the random polyalkylene glycol moiety, and

[0029] - The inhibitor does not contain NH2 groups, halogen atoms, or sulfur atoms.

[0030] Throughout this context, the inhibitor described above and used as compound (ii) in the acidic aqueous composition for electrolytic copper plating is referred to as "inhibitor (ii)". Preferred embodiments of the inhibitor (ii) are as defined below.

[0031] The inhibitor preferably does not contain a group covalently attached to one and / or one of the cyclic nitrogen atoms and the cyclic carbon atoms, which can be used as a group having a double or triple bond between two carbon atoms (e.g., alkenyl or alkynyl) for polymerization.

[0032] Throughout this context, the term "the inhibitor does not contain NH2 groups, halogen atoms, or sulfur atoms" means that the inhibitor does not contain covalently bonded NH2 groups, halogen atoms, or sulfur atoms within its organic structure. Conversely, if the inhibitor contains positively charged portions (atoms) within its organic structure, such as positively charged nitrogen atoms (shown as N), it indicates that the inhibitor does not contain any covalently bonded NH2 groups, halogen atoms, or sulfur atoms. + In this context, the negatively charged anti-charged group is a negatively charged ionic anti-charged group and can be a halide ion (e.g., chloride ion) or a sulfur-containing group (e.g., sulfate ion). The bonding between the positively charged portion within the organic structure and the negatively charged ionic anti-charged group is ionic (and not covalent), wherein, for example, the positively charged nitrogen atom remains covalently bonded to its adjacent atoms within the organic structure of the inhibitor. Therefore, the negatively charged anti-charged group does not affect the activity of the inhibitor and can dissociate in acidic aqueous compositions used for electrolytic copper plating.

[0033] In cases where the inhibitor contains a positively charged portion (atom) within its organic structure, the inhibitor also contains a negatively charged anti-charge group X. - Preferably, the negatively charged anti-charged group is a negatively charged ionic anti-charged group selected from the group consisting of sulfur-containing groups (e.g., sulfate groups). More preferably, the inhibitor also does not contain halide ions (e.g., negatively charged anti-charged groups).

[0034] In the context of this passage, the term “more than one” should be understood as two or more, three or more, four or more, and so on.

[0035] Furthermore, the objective is achieved by an electrolytic copper plating method, the method comprising the following steps:

[0036] (a) To provide or manufacture substrates suitable for electrolytic copper plating,

[0037] (b) The substrate obtained after step (a) or after another step after step (a) but before step (b) is brought into contact with the acidic aqueous composition according to the invention (as defined above, preferably as defined below) and an electric current is applied, such that the copper is electroplated onto the substrate as a copper deposit. Detailed Implementation

[0038] Based on our own experiments (see “Examples” in the context below), the acidic aqueous compositions according to the invention generally provide excellent copper filling (no voids) for structures exhibiting both low and high aspect ratios (see “Examples”). Furthermore, excellent surface distribution of copper deposition is possible across the entire substrate. In other words, the copper thickness is very uniform at every location on the substrate (for both pattern plating and panel plating).

[0039] Our own experiments have also shown that, compared with acidic aqueous compositions (not according to the invention) containing a polyethylene glycol substitute component (ii), the acidic aqueous compositions according to the invention (as defined above) exhibit a significantly increased overpotential.

[0040] The acidic aqueous composition according to the invention (as defined above) is an aqueous solution. The term "aqueous solution" means that the prevailing liquid medium (which is the solvent in the composition) is water. In some cases, the composition preferably contains a water-miscible liquid. The preferred liquid is a water-miscible alcohol. For ecological reasons, water is preferred as the sole solvent.

[0041] The acidic aqueous composition according to the invention (as defined above, preferably defined as preferred) is generally prepared by dissolving all components and compounds separately (and then stirring) in an aqueous liquid medium (preferably water).

[0042] The compositions according to the invention (as defined above, preferably) contain one or more acids, preferably selected from the group consisting of sulfuric acid, fluoroboric acid, phosphoric acid, and methanesulfonic acid. Based on the total volume of the composition, the total amount of one or more acids in the compositions according to the 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. If the total amount is much higher than 400 g / L, the effect is that bottom-up filling in the trench may be insufficient. These acids are preferably counted in one, two, three, or more than three other compounds.

[0043] The pH value of the composition according to the invention (preferably defined as "preferred") is 3 or lower, preferably 2 or lower, measured at a temperature of 20°C. This means that the pH value of the composition of the invention is 3 or lower, preferably 2 or lower. In the context of the invention, the pH value is measured at a temperature of 20°C, that is, the defined pH value reference is 20°C. Therefore, the composition is at a temperature of 20°C only for the purpose of pH measurement. This does not mean that the composition of the invention itself is limited to a specific temperature of 20°C. For the preferred temperature of the composition, see below.

[0044] If the pH is much higher than 3, the effect is that the conductivity of the composition is mostly insufficient, leading to an imbalance in the current density of the composition during electroplating. Furthermore, a pH of 3 or below prevents the formation of insoluble copper oxide. Therefore, no misalignment agent is required in the compositions of the present invention. Therefore, it is preferable that the acidic aqueous compositions used for electrolytic copper plating according to the present invention are substantially free of (preferably free of) misalignment agents. The absence of misalignment agents is preferred because the risk of organic additives being included in the copper deposit is further minimized. If the compositions of the present invention do not contain misalignment agents, then a significant carbon content is generally not observed in the copper deposit. Preferably, based on the total weight of the electroplated copper, the electroplated copper obtained by the method of the present invention contains at least 99% by weight copper, more preferably at least 99.9% by weight copper.

[0045] The acidic aqueous composition for electrolytic copper plating according to the present invention comprises 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 p-toluenesulfonate, and alkyl sulfonates. Preferred alkyl sulfonate is copper methanesulfonate. The most preferred copper source is copper sulfate, and most preferably CuSO4·5H2O.

[0046] Preferably, based on the total volume of the acidic aqueous composition, the total amount of copper sulfate (CuSO4·5H2O) in the acidic aqueous composition used for electrolytic copper plating according to the invention is from 12 g / L to 275 g / L, more preferably from 20 g / L to 275 g / L. In some specific cases, a total amount of 30 g / L to 80 g / L is preferred, while in other specific cases, a total amount of 180 g / L to 220 g / L is preferred. If a source other than CuSO4·5H2O is used, the individual molar amounts per liter can be calculated by those skilled in the art for the total amount of copper(II) ions. In some cases, the total amount of copper(II) ions (regardless of the copper source) preferably corresponds to the aforementioned concentration of copper sulfate (CuSO4·5H2O) in g / L.

[0047] Generally, in the compositions according to the invention (as defined above, preferably defined 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, based on the total volume of the composition.

[0048] Preferably, the composition of the present invention comprises, wherein the copper(II) ions in the composition represent at least 95 mol% of all depositable metal cations in the composition, more preferably at least 98 mol%, even more preferably at least 99 mol%, and most preferably 99.9 mol%. A “depositable metal cation” is a cation that, if an electric current is applied, is deposited in metallic form along with copper. This “depositable metal cation” is, for example, tin, nickel, and silver.

[0049] Preferably, the composition of the present invention comprises, wherein the copper(II) ions in the composition represent at least 95 mol% of all transition metal cations in the composition, more preferably at least 98 mol%, even more preferably at least 99 mol%, and most preferably at least 99.9 mol%. More preferably, the composition of the present invention comprises, wherein the copper(II) ions in the composition represent at least 95 mol% of all transition metal cations together with metal ions of Groups III, IV, and V of the periodic table, more preferably at least 98 mol%, even more preferably at least 99 mol%, and most preferably at least 99.9 mol%.

[0050] Preferably, the acidic aqueous composition of the present invention is not used on copper alloys.

[0051] The most preferred composition is that of the present invention, wherein the copper(II) ion is the only depositable 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, based on the total weight of the electroplated copper, that contains at least 99.5% by weight copper.

[0052] Preferably, the composition of the present invention contains (preferably does not contain) transition metals other than copper. Also preferably, the composition contains (preferably, in addition to the foregoing) aluminum, gallium, indium, tin, and lead.

[0053] In the context of this invention, the term "substantially free of" a target (e.g., a compound, metal ion, etc.) means that the target is not present at all or is present only in a very small and inconsequential amount without affecting the intended purpose of the invention. For example, this target may be unintentionally added or utilized (e.g., as an unavoidable impurity). "Substantially free of" preferably means, if defined for the composition, then based on the total weight of the composition of the invention, or if defined for the electroplated copper, then based on the total weight of electroplated copper obtained by the method of the invention, 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.

[0054] The acidic aqueous composition for electrolytic copper plating of the present invention (preferably defined as above) comprises one or more inhibitors (ii) (preferably at least one or more inhibitors (ii) as defined in the context). In some cases, the acidic aqueous composition for electrolytic copper plating of the present invention (preferably defined as above) preferably comprises only one inhibitor (ii) (preferably one inhibitor (ii) as defined in the context). Without wishing to be bound by theory, it is assumed that the inhibitor (ii) of the present invention combines the positive characteristics of different known inhibitors and leveling agents. By using the inhibitor (ii) of the present invention, no other inhibitors (iii) and / or leveling agents are required, or at least the concentrations of said other inhibitors and / or leveling agents can be very low.

[0055] Throughout the context, the term "independently" (e.g., in terms such as "independently selected" or "independently represented") is used for parts and groups. The meaning of this term is explained by the following example: For an exemplary compound X having exemplary groups E, F, and G, "E, F, and G are independently selected from the group consisting of [...]". This means (i) that the exemplary group F in the exemplary compound X is independently selected from the exemplary groups E and G in the exemplary compound X, and (ii) that the exemplary group F in the exemplary compound X is independently selected from other exemplary groups F in other exemplary compounds (e.g., exemplary compound Y).

[0056] Throughout this context, the term "alkyl" is used and refers to a monovalent group (C10) derived from an alkane by removing a hydrogen atom from any carbon atom. n H 2n+1Terms such as "C3 to C16 alkyl" refer to alkyl groups having 3 to 16 carbon atoms (n = 3 to 16). In the context of the term, C3 alkyl explicitly includes n-propyl and isopropyl, C4 alkyl explicitly includes n-butyl, isobutyl, sec-butyl, and tert-butyl, and C5 alkyl explicitly includes... and The dashed lines represent covalent bonds (connecting bonds) that link individual carbon atoms of an alkyl group to individual atoms of the molecule.

[0057] Throughout this context, the term "polypropylene" is used and refers to polypropylene that can be based on n-propyl units or isopropyl units.

[0058] Preferably, in the acidic aqueous composition (as defined above, preferably defined as preferred) used for electrolytic copper plating of the present invention, the total amount of component (ii) (the total amount of one inhibitor (ii), or, if more than one inhibitor (ii) is present, the total amount of all inhibitors (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, based on the total volume of the acidic aqueous composition. Preferably, the total amount is no more than 1 g / L, preferably no more than 700 mg / L, and more preferably no more than 500 mg / L, based on the total volume of the acidic aqueous composition. An acidic aqueous composition for electrolytic copper plating of the present invention is preferred, wherein, based on the total volume of the acidic aqueous composition, one or more inhibitors (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.

[0059] Preferably, the acidic aqueous composition for electrolytic copper plating according to the present invention (as defined above, preferably defined as preferred) comprises:

[0060] (iii) At least one other inhibitor different from inhibitor (ii).

[0061] and / or

[0062] (iv) At least one accelerator that is different from the inhibitors (ii) and (iii).

[0063] Preferably, the acidic aqueous composition for electrolytic copper plating according to the invention (as defined above, preferably defined as preferred) comprises one, two, three, or more than three other compounds that are different from the inhibitor (ii), additional inhibitor (iii), or accelerator (iv). Preferably, the one, two, three, or more than three other compounds are selected from the group consisting of: one or more species of inorganic ions, one or more leveling compound, and one or more wetting agents.

[0064] Preferably, the compositions of the present invention are substantially free of (preferably not containing) misalignment agents.

[0065] Preferred species of inorganic ions are those selected from the group consisting of halide ions (preferably chloride ions) and sulfate ions. These can be added wholly or partially to the acidic aqueous composition according to the invention using a copper source (see above for various copper sources). Other suitable sources of halide ions are, for example, hydrochloric acid or alkali metal halides (e.g., sodium chloride).

[0066] Preferably, the composition of the present invention contains one, two, three or more other compounds comprising halide ions, preferably chloride ions.

[0067] Preferably, in the acidic aqueous composition (as defined above, preferably defined as preferred) used for electrolytic copper plating according to the invention, the total amount of chloride ions, based on the total volume of the acidic aqueous composition, is in the range of 0.01 to 0.18 g / L, preferably in the range of 0.03 to 0.10 g / L. Preferably, based on the total volume of the acidic aqueous composition, the total amount of hydrochloric acid is in the range of 0.01 to 0.18 g / L, preferably in the range of 0.03 to 0.10 g / L.

[0068] In a preferred embodiment of the invention, the inhibitor (II) does not contain halides (e.g., negatively charged anti-charge groups) so as not to add additional halide ions (especially chloride ions) to the acidic aqueous composition used for electrolytic copper plating.

[0069] The acidic aqueous composition for electrolytic copper plating according to the present invention (as defined above, preferably) preferably contains sulfuric acid. Preferably, based on the total volume of the acidic aqueous composition, 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, more preferably in the range of 5 g / L to 220 g / L. More preferably, the total amount is in the range of 5 g / L to 140 g / L or 180 g / L to 220 g / L. The sulfuric acid may also be partially or completely replaced by fluoroboric acid, methanesulfonic acid, or other acids.

[0070] In some cases, the acidic aqueous composition according to the invention preferably contains a redox pair, more preferably Fe(II) / Fe(III) ions. This redox pair is particularly useful when reverse pulse plating is used in combination with an inert anode for copper deposition. Processes suitable for copper plating using a combination of a redox pair with reverse pulse plating and an inert anode are disclosed, for example, in US 5,976,341 and US 6,099,711.

[0071] At least one accelerator (iv) is preferably selected from the group consisting of: thiols, sulfides, disulfides, and polysulfides. More preferably, the accelerator is selected from the group consisting of: 3-(benzothiazolyl-2-thio)-propylsulfonic acid, 3-mercaptopropane-1-sulfonic acid, ethyl dithiodipropylsulfonic acid, bis-(p-thiophenyl)-disulfide, bis-(ω-sulfobutyl)-disulfide, bis-(ω-sulfohydroxypropyl)-disulfide, bis-(sodium sulfopropyl)-disulfide, bis-(ω-sulfopropyl)-disulfide, bis-(ω-sulfopropyl)-sulfide, Methyl-(ω-sulfopropyl)-disulfide, methyl-(ω-sulfopropyl)-trisulfide, O-ethyl-dithiocarbonate-S-(ω-sulfopropyl)-ester, thioglycolic acid, thiophosphate-O-ethyl-bis-(ω-sulfopropyl)-ester, 3-N,N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid, 3,3'-thiobis(1-propanesulfonic acid), thiophosphate-tris(ω-sulfopropyl)-ester, and their corresponding salts. Based on the total volume of the acidic aqueous composition, 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.

[0072] At least one additional inhibitor (iii) is preferably selected from the group consisting of: polyvinyl alcohol, carboxymethyl cellulose, polyethylene glycol, polypropylene glycol, polyethylene stearate, alkoxylated naphthol, polyethylene oleate, stearyl alcohol polyethylene glycol ether, nonylphenol polyethylene glycol ether, octyl alcohol polyalkyl glycol ether, octyl glycol-bis-(polyalkyl glycol ether), poly(ethylene glycol-random-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-random-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 the additional inhibitor compound 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.

[0073] Our experiments have shown that acidic aqueous reference compositions (not according to the invention; that is, without inhibitor (ii) but containing additional inhibitor (iii) (e.g., as defined above) generally also result in smoother, more uniform copper surfaces compared to those obtained in the absence of this additional inhibitor (iii). Furthermore, many of the aforementioned compounds generally also possess sufficient overpotential in individual reference compositions. However, the overpotential obtained in these reference compositions is generally much lower compared to the acidic aqueous compositions according to the invention.

[0074] Therefore, in some cases, the acidic aqueous compositions according to the invention preferably contain, and preferably do not contain, one or more additional inhibitors selected from the group consisting of: polyvinyl alcohol, carboxymethyl cellulose, polyethylene glycol, polypropylene glycol, polyethylene stearate, alkoxylated naphthol, polyethylene oleate, stearyl alcohol polyethylene glycol ether, nonylphenol polyethylene glycol ether, octyl alcohol polyalkyl glycol ether, octyl glycol-bis-(polyalkyl glycol ether), poly(ethylene glycol-random-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, the inclusion of one or more additional inhibitors as defined above appears acceptable. In many cases, our own experiments have shown that the relatively high overpotential generated in the acidic aqueous compositions according to the invention is not negatively affected in the presence of additional inhibitors as defined above.

[0075] Additionally, in some cases, at least one leveling compound may be used. Preferred leveling agents are selected from the group consisting of nitrogen-containing leveling compounds, such as polyethyleneimine, alkoxylated polyethyleneimine, alkoxylated lactams and their polymers, diethylenetriamine and hexamethylenetetramine, dyes (e.g., Jenus Green B, Bismarck Brown Y, and Acid Violet 7), sulfur-containing amino acids (e.g., cysteine), and phenazine onium salts. Other nitrogen-containing leveling agents may be peptides carrying polyethyleneimine, amino acids carrying polyethyleneimine, peptides carrying polyvinyl alcohol, amino acids carrying polyvinyl alcohol, peptides carrying polyalkylene glycol, amino acids carrying polyalkylene glycol, pyrroles carrying aminoalkylene groups, and pyridines carrying aminoalkylene groups. Suitable urea-based polymers have been disclosed in EP2735627A1 and EP 2922985A1, and the aforementioned amino acids and peptides carrying polyalkylene glycols have been disclosed in EP 2113587 B9. EP3497267 discloses end-capped polyether compounds. EP 2537962 A1 teaches pyrrole and pyridine carrying suitable aminoalkyl compounds. WO 2016169952 A1 teaches suitable end-capped guanidine compounds. Based on the total volume of the composition, the total amount of leveling compound in the acidic aqueous composition according to the invention is preferably in the range of 0.1 mg / L to 100 mg / L. Our experiments have shown that these leveling compounds generally improve process stability.

[0076] In rare cases, based on our own experiments, some leveling compounds as defined above have a slightly negative (but still acceptable) effect on the overpotential generated in the acidic aqueous compositions according to the invention. Therefore, in rare cases, the acidic aqueous compositions according to the invention (as defined above, preferably) preferably contain, and preferably do not contain, one or more leveling compounds as defined above. In one embodiment of the acidic aqueous composition according to the invention, the leveling agent is preferably not polyethyleneimine (PEI).

[0077] Preferably, the acidic aqueous composition according to the invention contains at least one wetting agent. These wetting agents are also referred to as surfactants in the art. The at least one wetting agent is preferably selected from the group consisting of nonionic, cationic, and anionic surfactants. Based on the total weight of the acidic aqueous composition, the total amount of wetting agent in the acidic aqueous composition according to the invention is preferably in the range of 0.01 to 5% by weight.

[0078] As mentioned above, the acidic aqueous composition according to the present invention contains one or more inhibitors (ii) consisting of or comprising a single N-heteroaromatic monocycle, said monocycle comprising at least two cyclic nitrogen atoms and more than one substituent covalently attached to one and / or one cyclic carbon atom of said cyclic nitrogen atom, wherein said substituent is independently or comprises:

[0079] - One or more linear or branched polyalkylene glycol moieties, and / or

[0080] - One or more linear or branched polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moieties.

[0081] Preferably, in the acidic aqueous composition according to the invention, one or more linear or branched polyalkylene glycol portions independently comprise polyethylene glycol portions and / or polypropylene glycol portions, wherein the polypropylene may be based on n-propyl units or isopropyl units, preferably polyethylene glycol portions.

[0082] According to the present invention, the acidic aqueous composition is preferred, wherein one or more linear or branched polyalkylene glycol block polyalkylene glycol portions independently comprise polyethylene glycol-block-polypropylene glycol portions and / or polypropylene glycol-block-polyethylene glycol portions, preferably polyethylene glycol-block-polypropylene glycol portions, or one or more linear or branched random polyalkylene glycol portions independently comprise random polyethylene glycol-polypropylene glycol portions, wherein the polypropylene may be based on n-propyl units or isopropyl units.

[0083] Preferably, in the acidic aqueous composition according to the invention, one or more inhibitors (ii) comprise a total of 1 to 4, preferably 2 to 3, and most preferably 3 aromatic ring carbon atoms.

[0084] Preferably, in the acidic aqueous composition according to the invention, a single N-heteroaromatic monocyclic ring is a 6-membered ring or a 5-membered ring, preferably a 5-membered ring.

[0085] According to the present invention, it is preferred that a single N-heteroaromatic monocyclic ring does not contain an epoxy atom. Preferably, the acidic aqueous composition according to the present invention is wherein one or more inhibitors (ii) are composed of carbon atoms, hydrogen atoms, nitrogen atoms, and oxygen atoms.

[0086] The acidic aqueous composition according to the invention is preferred, wherein one of the single N-heteroaromatic monocyclic rings is selected from the group consisting of: pyrazole ring, imidazole ring, 1,3,5-triazine ring, 1,2,4-triazine ring, 1,2,3-triazine ring and tetrazolium ring, preferably selected from the group consisting of: imidazole ring and 1,3,5-triazine ring, and most preferably imidazole ring.

[0087] The acidic aqueous composition according to the invention is preferred, wherein in one or more inhibitors (ii), one of the substituents is covalently attached to one of the at least two cyclic nitrogen atoms, such that the nitrogen atom is positively charged.

[0088] Preferably, in the acidic aqueous composition according to the invention, each of one or more linear or branched polyalkylene glycol moieties and each of one or more polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moieties contains a terminal alkyl group, preferably C1 to C4 alkyl, and most preferably methyl.

[0089] The acidic aqueous composition according to the invention is preferred, wherein one or more inhibitors (ii) do not contain an aromatic ring structure other than a single N-heteroaromatic monocycle, and preferably do not contain any ring structure other than a single N-heteroaromatic monocycle.

[0090] Based on our own experiments, excellent results are obtained if one or more inhibitors (ii) are selected from the following group:

[0091]

[0092] Each independently

[0093] -R represents a straight-chain or branched polyalkylene glycol moiety, a straight-chain or branched polyalkylene glycol block polyalkylene glycol moiety, or a random polyalkylene glycol (as defined above, preferably defined as preferred), and R 1 It is an alkyl group, preferably methyl, ethyl or propyl, most preferably methyl, and

[0094] -n represents 0, 1, 2, 3, 4 or 5, preferably 0, 1, 2 or 3.

[0095] Therefore, compounds (Ia), (Ib), (Ic), (Id), (Ie), and / or (If) are preferred as inhibitors (ii) in the acidic aqueous compositions according to the invention. Specifically, it is preferred to use (Ia), (Ib), (Ic), and / or (If) containing positively charged nitrogen.

[0096] The acidic aqueous composition of the present invention is further preferred, wherein one or more inhibitors (ii) are selected from the group consisting of:

[0097]

[0098]

[0099] and

[0100]

[0101] Each of them independently

[0102] -a represents an integer in the range of 2 to 22, preferably in the range of 3 to 20, and most preferably in the range of 4 to 16.

[0103] -b represents an integer in the range of 2 to 22, preferably in the range of 3 to 20, and most preferably in the range of 4 to 16. Therefore, the specific acidic aqueous compositions of the present invention for electrolytic copper plating (preferably defined as preferred, as defined above) are particularly preferred. These are highly preferred specific inhibitors (ii), and thus, highly preferred compositions of the present invention comprising one or more inhibitors (ii) are produced.

[0104] Based on our own experiments, these compounds exhibit excellent plating results and sufficiently high overpotentials compared to PEG. These compounds are used in acidic aqueous compositions for electrolytic metal plating, preferably for electrolytic copper plating, and more preferably in compositions and methods as defined in this invention.

[0105] Preferably, in the acidic aqueous composition of the present invention, the weight-average molecular weight (Mw) of the inhibitor (ii), as determined by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene, 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, and more preferably in the range of 700 g / mol to 3,000 g / mol.

[0106] The present invention also relates to the use of the acidic aqueous composition of the present invention (as defined above, preferably as preferred) for electrolytic copper plating, preferably for void-free copper-filled recessed structures (preferably recessed structures with an aspect ratio in the range of 1:20 to 20:1). Preferred recessed structures are trenches, micro-blind vias, and through-holes.

[0107] The acidic aqueous composition of the present invention is preferred, wherein at least one other inhibitor (inhibitor (iii)) different from inhibitor (ii) is a polymer containing nitrogen and / or oxygen, said polymer preferably selected from the group consisting of: polyvinyl alcohol, carboxymethyl cellulose, polyethylene glycol, polypropylene glycol, polyethylene stearate, alkoxylated naphthol, polyethylene oleate, stearyl alcohol polyethylene glycol ether, nonylphenol polyethylene glycol ether, octyl alcohol polyalkyl glycol ether, octyl glycol-bis-(polyalkyl glycol ether), poly(ethylene glycol-random-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 (also known as poloxamer) bound to the central ethylenediamine moiety.

[0108] The concentration of the optional other inhibitor (iii) is preferably in the range of 0.0005 g / L to 1 g / L, more preferably in the range of 0.001 g / L to 0.5 g / L.

[0109] The features of the acidic aqueous composition of the present invention mentioned above (preferred features as preferred features) are also applicable to the use of the acidic aqueous composition for electrolytic copper plating and void-free copper filling.

[0110] The present invention also relates to the use of an inhibitor (ii) as defined above in an acidic aqueous composition for electrolytic metal plating, preferably for electrolytic copper plating in an acidic aqueous composition, and more preferably for electrolytic copper plating according to the present invention in an acidic aqueous composition (as defined above, preferably is defined as preferred).

[0111] The characteristics of the acidic aqueous composition mentioned above (as defined above, preferably defined 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.

[0112] Furthermore, the present invention relates to an inhibitor for electrolytically deposited copper deposits, said inhibitor comprising, preferably, the following:

[0113] - A single N-heteroaromatic monocycle, the monocycle comprising at least two cyclic nitrogen atoms and more than one substituent covalently attached to one and / or one cyclic carbon atom of the cyclic nitrogen atoms, wherein the substituent is independently or comprises:

[0114] - One or more linear or branched polyalkylene glycol moieties, and / or

[0115] - One or more linear or branched polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moieties

[0116] The conditions are

[0117] -If the inhibitor contains OH groups, then these are the terminal OH groups of the polyalkylene glycol moiety and the polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moiety, respectively.

[0118] - The compound does not contain NH2 groups, halogen atoms, or sulfur atoms.

[0119] The inhibitor according to the invention is preferred, wherein the inhibitor is selected from the group consisting of:

[0120]

[0121]

[0122] and

[0123]

[0124] Each independently

[0125] -a represents an integer in the range of 2 to 22, preferably in the range of 3 to 20, and most preferably in the range of 4 to 16.

[0126] -b indicates an integer in the range of 2 to 22, preferably in the range of 3 to 20, and most preferably in the range of 4 to 16.

[0127] Preferably, the inhibitor is a compound of formula (IIb), (IIb'), (IId) or (IIe), and even more preferably, the inhibitor is a compound of formula (IIb), (IIb') or (IIe).

[0128] In one embodiment of the invention, preferably, if a single N-heteroaromatic monocyclic ring is an imidazole ring, then one or more linear or branched polyalkylene glycol portions are not polyethylene glycol portions, preferably if one or more linear or branched polyalkylene glycol portions are not polyethylene glycol portions.

[0129] The features of the inhibitor (ii) contained in the aqueous composition for electrolytic copper plating according to the present invention (as defined above, preferably defined as preferred) mentioned above also apply to the aforementioned inhibitor according to the present invention.

[0130] It is preferred, even more preferred, to use compounds (IIa), (IIb), (IIb'), (Ic), (Id), (Ie) and / or (If) as inhibitors (ii) in the acidic aqueous composition for copper electroplating according to the invention, and most preferably to use inhibitors (IIb), (IIb'), (IId) and (IIe), with (IIb), (IIb') or (IIe) being the most preferred.

[0131] Furthermore, the present invention relates to a method for electrolytic copper plating, which includes the following steps:

[0132] (a) Providing or manufacturing a substrate suitable for electrolytic copper plating, preferably a substrate having a structured layer on its surface.

[0133] (b) Contacting the substrate obtained in step (a) or in a further step after step (a) but before step (b) with the acidic aqueous composition according to the invention (as defined above, preferably defined as preferred),

[0134] An electric current is applied so that the copper is electroplated (deposited) onto the substrate as a copper deposit.

[0135] In the method according to the invention, a substrate and at least one anode are connected to a current or individual voltage source. Once current is applied, copper is electroplated (deposited) onto the substrate (at least on a portion of the substrate surface). In some cases, step (b) is performed directly after step (a). In other cases, a cleaning and / or rinsing step is preferably included as an additional step after step (a). In this case, a cleaned / rinsed substrate is obtained. Preferably, this cleaned / rinsed substrate is in direct contact as defined in step (b).

[0136] Preferably, the substrate is selected from the group consisting of: printed circuit boards, IC substrates, semiconductor wafers, ceramic and glass substrates. Substrates from the aforementioned group are preferred, having recessed structures such as trenches, micro-blind vias, through-silicon vias, through-holes, and through-glass vias. Therefore, the substrate preferably includes one or more recessed structures selected from the group consisting of trenches, micro-blind vias, and through-holes. In the method of the invention, these structures are preferably filled with copper without voids (see “Examples” below). Therefore, the method of the invention is preferred in which, in step (b), a current is applied such that copper is electroplated onto the substrate, and the recessed structures, preferably trenches, micro-blind vias, and through-holes, are filled with copper without voids. The method can also be used for substrates processed using a dual damascene process.

[0137] In many cases, the substrate preferably contains a metal seed layer, more preferably a copper seed layer. In some cases, the substrate preferably comprises resin, ceramic, glass, or silicon, more preferably having a metal seed layer, and even more preferably having a copper seed layer.

[0138] During the electrolytic copper plating method according to the invention, it is preferable to agitate the acidic aqueous composition according to the invention, more preferably by strong inflow, and, where applicable, by blowing in clean air, so that the surface of the composition is subjected to strong motion. This means maximizing material transport near the cathode and anode, making higher current densities possible. The motion of the cathode also improves material transport at individual surfaces. In addition, convection can also be generated in the composition by rotating the substrate. By means of increased convection and electrode motion, deposition with constant diffusion control is achieved. The substrate can be moved horizontally and vertically and / or by means of vibration. Combining this with blowing air into the composition is particularly effective and therefore preferred.

[0139] In the electrolytic copper plating method according to the present invention (as described above, preferably as described above), step (b) is preferably carried out at a temperature in the range of 15°C to 50°C, more preferably 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.

[0140] Preferably, it is applied at 0.05 A / dm2 Up to 12A / dm 2 Within the range, more preferably within 0.1 A / dm 2 Up to 7A / dm 2 Within the range, or even more preferably within 0.1 A / dm 2 Up to 3A / dm 2 The cathode current density (average density) is within the range mentioned above. However, current densities exceeding the range mentioned above are not excluded, especially for pulse electroplating methods.

[0141] Preferably, step (b) in the electrolytic copper plating method according to the present invention (as described above, preferably described as preferred) is performed 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.

[0142] Pulse plating typically involves unipolar pulsed currents, where the deposition current is interrupted by a regular pause. Reverse pulse plating typically involves pulses of reverse current during the plating process.

[0143] A reverse pulse electroplating method has been developed for electrolytic deposition, particularly for electrolytic deposition of copper on circuit boards with high aspect ratios, and is described (for example) in DE 42 25 961 C2 and DE 27 39 427 A 1. Improved surface distribution and plating uniformity are achieved in vias using higher current densities.

[0144] In the method of the present invention (as defined above, preferably defined as preferred), an inert (insoluble) or soluble anode is used. In some cases, an inert anode is preferred. Insoluble anodes are inert during the electroplating process and therefore do not change their shape. This results in a geometry with a time constant during the electroplating process. Preferred insoluble anodes are those coated with a mixture of noble metal oxides (e.g., a coating of ruthenium oxide and iridium oxide), particularly noble metals (e.g., platinum) or so-called valve metals (e.g., titanium), which are also coated with a coating of noble metal oxides (e.g., a coating of ruthenium oxide and iridium oxide). In some cases, the insoluble anode is preferably in the form of a porous metal. To obtain a copper ion supplement when using an insoluble anode, it is necessary to dissolve a copper compound in the acidic aqueous composition according to the present invention (see above for the copper source), or to contact metallic copper with the composition. The metallic copper dissolves under the influence of oxygen dissolved in the composition or with the aid of compounds that form the oxidized form of a redox system, for example with the aid of Fe(III) ions dissolved in the composition thereby reduced to Fe(II) ions. The Fe(II) ions are oxidized back to Fe(III) ions at an insoluble anode. The Fe(II) / Fe(III) ions may originate (e.g.) from the corresponding ferric sulfate. Based on the total volume of the composition, the concentration of Fe(II) ions in the composition is preferably 8 to 12 g / L and the concentration of Fe(III) ions is preferably 1 to 5 g / L.

[0145] However, in other cases, soluble copper anodes are preferred. Copper consumed during the deposition (electroplating) process is typically replenished electrochemically via a soluble copper anode. Soluble copper anodes having a phosphorus content of 0.02 to 0.067% by weight are particularly preferred.

[0146] In the method according to the invention, copper is preferably electroplated in a conventional manner by immersing the substrate in a composition located in an immersion bath and polarizing the substrate relative to an anode located in the same composition, and also by a horizontal electroplating method. The latter electroplating method is carried out in a conventional horizontal apparatus by which the substrate is transported in a horizontal position and transport direction while being contacted with an acidic aqueous composition. The anode is also positioned horizontally in 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 3236 545 A1. Additionally, semiconductor wafers are preferably processed in so-called plating cups, where the individual wafers are positioned horizontally above the anode, which is also positioned horizontally. The plating cups are filled with the acidic aqueous composition according to the invention. Thus, both the wafers and the anode are in contact with the composition. Preferably, the wafers are rotated during the deposition process.

[0147] Furthermore, the characteristics of the acidic aqueous composition mentioned above (as defined above, preferably defined as preferred) are preferably applicable to the electrolytic copper plating method according to the present invention.

[0148] The method according to the invention is preferred, wherein an electroplated copper deposit forms a plurality of copper pillars and / or a plurality of copper conductive traces, preferably wherein the copper deposit is a plurality of copper conductive traces, more preferably wherein the copper deposit is a plurality of copper conductive traces in a redistribution layer. The plurality of copper pillars are preferably electroplated via a so-called bottom-up electroplating process with a recessed structure. The plurality of copper conductive traces, serving as through-holes, are preferably electroplated / filled via a so-called x-plating process, wherein the through-holes are first electroplated in the middle of the through-holes, the voids are sealed by creating blind holes, and then the created blind holes are filled.

[0149] The 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.

[0150] The 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.

[0151] The 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.

[0152] The method according to the invention is preferred in which, in step (b), a direct current is applied, preferably a direct current with a current density in the range of 0.1 ASD to 120 ASD, and most preferably, in step (b), only a direct current is applied, preferably only a direct current with a current density in the range of 0.2 ASD to 80 ASD.

[0153] The method according to the invention is preferred, wherein in step (b), a direct current is applied, preferably a direct current with a current density in the range of 0.1 ASD to 4 ASD.

[0154] The method according to the invention is preferred, wherein in step (b), a direct current is applied, preferably a direct current with a current density in the range of 1 ASD to 10 ASD.

[0155] The method according to the invention is preferred, wherein in step (b), a direct current is applied, preferably a direct current with a current density in the range of 10 ASD to 80 ASD.

[0156] The following examples illustrate the benefits of this invention.

[0157] Example

[0158] A. synthesis:

[0159] A1. Synthesis of compound (IIb):

[0160] In the first step, polyethylene glycol (PEG, Alfa Aesar, Mw = 202 g / mol) was subjected to a nucleophilic substitution reaction with p-toluenesulfonyl chloride (p-TsCl, Merck, 98%) contained in tetrahydrofuran (THF, VWR, 100%) / water at 0 °C for 20 hours to form toluenesulfonated polyethylene glycol ((bis-Ts)-PEG, yield: approximately 70%), which could be used in the next step without further purification.

[0161] In the second step, (bis-Ts)-PEG is subjected to a nucleophilic substitution reaction with polypropylene glycol monomethyl ether (PPG206, M = 206 g / mol, three monomer units) contained in THF at 50 °C for 20 hours in the presence of potassium tert-butoxide (KO-tert-butyl, Merck, 98%) to form toluenesulfonated polyethylene glycol-block-polypropylene glycol methyl ester (block intermediate, yield: approximately 15%).

[0162] In the third step, the block intermediate was subjected to a nucleophilic substitution reaction with imidazole (Merck, 100%) contained in THF at 65 °C for 165 h in the presence of KO-tertiary butyl to form compound (IIb) (yield: about 25%, Mw = 797). In subsequent steps, the compound was further purified by HPLC (ACN / H2O: 30 / 70 vol%; yield: about 10%).

[0163] A2. Synthesis of compounds of formula (IIc):

[0164] In the first step, polyethylene glycol monomethyl ether (PEGMe, Alfaezar, Mw = 350 g / mol) was reacted with trichlorotriazine (Acros Organics, 99%) contained in THF in the presence of KO-tert-butyl at a temperature ranging from 0°C to 60°C for 20 hours to form compound (IIc) (yield: approximately 23%, Mw = 963 g / mol). In a different method, PEGMe with Mw = 750 g / mol was used instead of PEGMe with Mw = 350 g / mol. Thus, compound (IIc) with Mw = 2152 g / mol was obtained.

[0165] B. Deposition results:

[0166] B1. Example 1: Acidic aqueous composition (according to the present invention):

[0167] In the first step, the electroplating bath is prepared by mixing the following: (i) 60 g / L of copper ions (added in the form of copper sulfate pentahydrate (II)CuSO4*5H2O (also used in the examples below), (ii) 0.010 g / L of a compound of formula (IIb), (iii) 50 g / L of sulfuric acid, (iv) 0.030 g / L of chloride ions (added in the form of HCl), and (v) 3 mL / L of disulfide as an accelerator. Acc 10), and (vi) deionized water.

[0168] In the second step, electrolytic copper plating is performed using the acidic composition prepared in the first step. The plating bath temperature is 25°C and an application rate of 2 mA / cm² is applied. 2 The current density was maintained for 50 minutes. A copper layer was electroplated onto a wafer substrate with a copper seed layer, a characteristic diameter of 10 μm, and an aspect ratio of approximately 6:1.

[0169] The vias are completely filled without defects (e.g., voids). The fill height is 68.2 μm. A cross-sectional photograph of the copper metallized wafer substrate is shown. Figure 1 middle.

[0170] B.2. Example 2: Acidic aqueous composition (comparative example, not based on the present invention):

[0171] Repeat Example 1, but in the acidic aqueous comparative composition according to Example 2 (not according to the invention), use 304 (a poly(ethylene oxide)-poly(propylene oxide) (PEO-PPO) block bound to the central ethylenediamine moiety) substitute (IIb) compound. 304 is a common additive in certain compositions, is commercially available, and is described in more detail in paragraph

[0027] of International Patent Application WO 2008157612 A1.

[0172] In the first step, a comparative composition was prepared by mixing the following: (i) a total amount of copper ions of 60 g / L, and (ii) a total amount of copper ions of 0.01 g / L. 304, (iii) 50 g / L of total sulfuric acid, (iv) 0.030 g / L of total chloride ions (added as HCl), (v) 3 mL / L of total disulfide as an accelerator. Acc 10), and (vi) deionized water.

[0173] In the second step, electrolytic copper plating is performed using the acidic composition prepared in the first step. The plating bath temperature is 25°C and an application rate of 2 mA / cm² is applied. 2 The current density was maintained for 50 minutes. A copper layer was electroplated onto a wafer substrate with a copper seed layer, a characteristic diameter of 10 μm, and an aspect ratio of approximately 6:1.

[0174] Incomplete filling (dimpling) of through-holes without defects (e.g., voids). The fill height is 60 μm. A cross-sectional photograph of the copper metallized wafer substrate is shown. Figure 2 middle.

Claims

1. An acidic aqueous composition for electrolytically depositing copper deposits, said composition comprising: (i) Copper(II) ions, (ii) One or more inhibitors comprising: A single N-heteroaromatic monocyclic ring comprising at least two cyclic nitrogen atoms and more than one substituent covalently attached to one and / or one cyclic carbon atom of the cyclic nitrogen atoms, wherein the substituent is independently or comprises: 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, The conditions are If the inhibitor contains OH groups, then these are terminal OH groups of the polyalkylene glycol moiety, the polyalkylene glycol block polyalkylene glycol moiety, or the random polyalkylene glycol moiety, and The inhibitor does not contain NH2 groups, halogen atoms, or sulfur atoms. One or more inhibitors mentioned in (ii) are selected from the group consisting of: Each independently R represents a straight-chain or branched polyalkylene glycol moiety, or a straight-chain or branched polyalkylene glycol block polyalkylene glycol, or a random polyalkylene glycol moiety, and R 1 It is an alkyl group, and n represents 0, 1, 2, 3, 4, or 5, and The inhibitor in (ii) has a weight-average molecular weight (Mw) in the range of 500 g / mol to 5000 g / mol.

2. The composition according to claim 1, wherein n represents 0, 1, 2 or 3.

3. The composition according to claim 1, further comprising: (iii) at least one other inhibitor different from the inhibitor described in (ii), and (iv) At least one accelerator that is different from the inhibitors described in (ii) and (iii).

4. The composition according to claim 3, wherein the at least one other inhibitor different from the inhibitor in (ii) is a polymer containing nitrogen and / or oxygen atoms.

5. The composition according to any one of claims 1 to 4, wherein the one or more inhibitors in (ii) are selected from the group consisting of: (IIa) (IIb) (IIb') (IIc) (IId), and (IIe), Each of them independently a represents an integer in the range of 2 to 22, and b represents an integer in the range of 2 to 22.

6. The composition according to claim 5, wherein a represents an integer in the range of 3 to 20.

7. The composition according to claim 5, wherein a represents an integer in the range of 4 to 16.

8. The composition according to claim 5, wherein b represents an integer in the range of 3 to 20.

9. The composition according to claim 5, wherein b represents an integer in the range of 4 to 16.

10. The composition according to any one of claims 1 to 4, wherein the inhibitor in (ii) has a weight average molecular weight (Mw) in the range of 600 g / mol to 4000 g / mol.

11. The composition according to any one of claims 1 to 4, wherein the inhibitor in (ii) has a weight average molecular weight (Mw) in the range of 700 g / mol to 3000 g / mol.

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

13. The composition according to any one of claims 1 to 4, wherein, based on the total volume of the acidic aqueous composition, one or more inhibitors in (ii) are present in a total amount ranging from 50 mg / L to 700 mg / L.

14. The composition according to any one of claims 1 to 4, wherein, based on the total volume of the acidic aqueous composition, one or more inhibitors in (ii) are present in a total amount ranging from 70 mg / L to 500 mg / L.

15. The composition according to any one of claims 1 to 4, wherein, based on the total volume of the acidic aqueous composition, one or more inhibitors in (ii) are present in a total amount ranging from 80 mg / L to 400 mg / L.

16. A method for electrolytic copper plating, comprising the following steps: (a) To provide or manufacture substrates suitable for electrolytic copper plating, (b) Contact the substrate obtained after step (a) or after another step after step (a) but before step (b) with the acidic aqueous composition of any one of claims 1 to 15 and apply an electric current such that the copper is electroplated onto the substrate as a copper deposit.

17. The method of claim 16, wherein the copper deposit forms a plurality of copper pillars and / or a plurality of copper conductive traces.

18. The method of claim 16 or 17, wherein the substrate comprises one or more recessed structures selected from the group consisting of trenches, micro-blind vias and through-holes.

19. An inhibitor for electrolytically deposited copper deposits, comprising the following: A single N-heteroaromatic monocyclic ring comprising at least two cyclic nitrogen atoms and more than one substituent covalently attached to one and / or one cyclic carbon atom of the cyclic nitrogen atoms, wherein the substituent is independently or comprises: 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, The conditions are If the inhibitor contains OH groups, then these are the terminal OH groups of the polyalkylene glycol moiety, the polyalkylene glycol block polyalkylene glycol moiety, and the random polyalkylene glycol moiety, respectively. The inhibitor does not contain NH2 groups, halogen atoms, or sulfur atoms. The inhibitors mentioned above are selected from the group consisting of: , , (Ib), (If) , (Id), and (Ie) Each independently R represents a straight-chain or branched polyalkylene glycol moiety, or a straight-chain or branched polyalkylene glycol block polyalkylene glycol, or a random polyalkylene glycol moiety, and R 1 It is an alkyl group, and n represents 0, 1, 2, 3, 4, or 5, and The inhibitor in (ii) has a weight-average molecular weight (Mw) in the range of 500 g / mol to 5000 g / mol.

20. An inhibitor for electrolytically depositing copper deposits, comprising the following: A single N-heteroaromatic monocyclic ring comprising at least two cyclic nitrogen atoms and more than one substituent covalently attached to one and / or one cyclic carbon atom of the cyclic nitrogen atoms, wherein the substituent is independently or comprises: 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, The conditions are If the inhibitor contains OH groups, then these are the terminal OH groups of the polyalkylene glycol moiety, the polyalkylene glycol block polyalkylene glycol moiety, and the random polyalkylene glycol moiety, respectively. The inhibitor does not contain NH2 groups, halogen atoms, or sulfur atoms. The inhibitors mentioned above are selected from the group consisting of: , , (Ib), (If) , (Id), and (Ie) Each independently R represents a straight-chain or branched polyalkylene glycol moiety, or a straight-chain or branched polyalkylene glycol block polyalkylene glycol, or a random polyalkylene glycol moiety, and R 1 It is an alkyl group, and n represents 0, 1, 2, 3, 4, or 5, and The inhibitor in (ii) has a weight-average molecular weight (Mw) in the range of 500 g / mol to 5000 g / mol.

21. The inhibitor according to claim 19 or 20, wherein n represents 0, 1, 2 or 3.

22. The inhibitor according to claim 19 or 20, wherein it is selected from the group consisting of: (IIb) (IIb') (IId), and (IIe), Each of them independently a represents an integer in the range of 2 to 22, and b represents an integer in the range of 2 to 22.

23. The inhibitor according to claim 22, wherein a represents an integer in the range of 3 to 20.

24. The inhibitor of claim 22, wherein a represents an integer in the range of 4 to 16.

25. The inhibitor of claim 22, wherein b represents an integer in the range of 3 to 20.

26. The inhibitor of claim 22, wherein b represents an integer in the range of 4 to 16.

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