Compositions and methods for forming nanotwinned copper

Abstract

A copper electrolyte comprising a copper salt, a source of halide ions, and a reaction product of an amine or sulfur-containing compound with 2,3-epoxy-1-propanol, optionally combined with one or more leveling agents or accelerators, for producing nanotwinned copper deposits. The copper electrolyte is used to initiate high-density nanotwinned copper deposition on various surfaces.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS)

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 414,725, filed October 10, 2022, the subject matter of which is incorporated herein by reference in its entirety.

[0003] FIELD OF THE INVENTION The present invention relates generally to the electrodeposition of nanotwinned copper on various substrates and to copper electroplating baths for producing dense nanotwinned copper deposits. [Background technology]

[0004] Electrochemical deposition processes are well established in integrated circuit manufacturing processes. Copper lines can be formed by electroplating metal into very thin, high aspect ratio trenches and vias in a method commonly referred to as a "damascene" process (pre-passivation metallization).

[0005] With the advancement of microelectronics, there is a constant need to create smaller and denser interconnect structures. Copper is one of the most essential conductors in microelectronic devices due to its high ductility and conductivity. One way towards this goal is to eliminate the solder between two separate substrates that connect copper vias, pads, bumps, or pillars, which can be replaced by, for example, Cu-Cu hybrid bonding.

[0006] To ensure the success of this method, which requires both high temperature and pressure, it is far preferable to produce (111)-oriented electroplated copper with >90% nanotwinned columnar copper (ntCu) grains.

[0007] Due to its combination of excellent mechanical properties, good electrical conductivity, and unique structure, nanotwinned copper has attracted attention for use in microelectronics. The mechanical strength of metals such as copper generally increases when the grain size of the crystals is reduced to the nanoscale level. Nanotwinned copper represents ultrafine-grained copper whose grains contain a high density of lamellar nanoscale twins separated by tightly packed twin boundaries. By introducing nanoscale twins into the copper microstructure, properties including mechanical strength, ductility, electromigration resistance, and hardness can be improved.

[0008] Nanoscale metal thin films can have exemplary mechanical properties. As a result, metals with nanotwin crystalline properties can be suitable for applications such as through silicon vias (TSVs), semiconductor chip interconnects, packaging substrate pin-through holes, metal interconnects (e.g., copper interconnects), or metal materials on substrates.

[0009] Nanotwinned copper can be achieved in several ways, including, for example, sputtering and electrolytic deposition using copper electroplating compositions optimized to produce nanotwinned copper.

[0010] One of the advantages of sputtering is the high purity in the copper film, along with the ability to align the grains in a preferred orientation. Sputtered (111)-oriented nanotwinned copper has been shown to have high thermal stability and strength.

[0011] On the other hand, DC electroplating has the advantage of being highly adaptable to industrial mass production.Electroplated nanotwinned copper can be classified into two groups: equiaxed grain nanotwinned copper and (111) oriented nanotwinned copper.

[0012] Crystal defects can affect the mechanical, electrical, and optical properties of materials. Twinning occurs in materials where two parts of the crystal structure are symmetrically related to each other. In face-centered cubic (FCC) crystal structures, including copper, coherent twin boundaries can form as (111) mirror symmetry planes, where the typical stacking order of the (111) plane is reversed. In other words, adjacent grains are mirror-imaged across coherent twin boundaries in a layered (111) structure. Twins grow in a layered manner extending along the lateral (111) crystal planes, and the twin thickness is on the order of nanometers. Nanotwinned copper exhibits excellent mechanical and electrical properties and can be used in a wide variety of applications in wafer-level packaging and advanced packaging design.

[0013] Compared to copper exhibiting conventional grain boundaries, nanotwinned copper has strong mechanical properties, including high strength and high tensile ductility. For example, nanotwinned copper has demonstrated high electrical conductivity, which can be attributed to twin boundaries, which cause less significant electron scattering compared to grain boundaries. Nanotwinned copper also exhibits high thermal stability, which can be attributed to twin boundaries having excess energies orders of magnitude lower than those of grain boundaries, allowing for high copper atomic diffusivity, which is useful for direct copper-to-copper bonding. In addition, nanotwinned copper exhibits high resistance to electromigration, which can be a result of twin boundaries slowing down electromigration-induced atomic diffusion. Nanotwinned copper has demonstrated strong resistance to seed etching, which can be important in fine wire redistribution layer applications, and also exhibits low impurity incorporation, which results in fewer Kirkendall voids as a result of solder reactions with nanotwinned copper.

[0014] In some embodiments, nanotwinned copper enables direct copper-copper bonding, which can occur at low temperatures, moderate pressures, and lower bonding forces / times. Typically, deposition of copper structures results in a rough surface, and in some cases, electrodeposition of nanotwinned copper can be performed, followed by electropolishing, to achieve a smooth surface prior to copper-copper bonding. Nanotwinned copper structures with smooth surfaces can be used in copper-copper bonding with shorter bonding times, lower temperatures, and fewer voids.

[0015] U.S. Patent No. 7,074,315 to Desmaison et al., the entire subject matter of which is incorporated herein by reference, describes a copper electrolyte for depositing matte layers of copper, but there is no suggestion regarding the use of Desmaison's copper electrolyte for depositing nanotwinned copper.

[0016] WO 2020 / 092244 to Banik et al., the entire subject matter of which is incorporated herein by reference, describes a copper structure having a high density of nanotwinned copper deposited on a substrate. Banik does not describe any particular electrolytic copper plating bath, but instead focuses on electroplating conditions that include applying a pulsed current waveform that alternates between constant and no current, the duration of which no current is applied being substantially longer than the duration of which the constant current is applied.

[0017] U.S. Patent No. 10,566,314 to Yang, the entire subject matter of which is incorporated herein by reference, describes how a columnar grain microstructure is the optimal copper grain structure for Cu-Cu metallurgy for metallurgical joining. The disclosed copper grain microstructure plated with an inhibitor-only system produces a columnar grain structure as a result of plating nanotwinned copper. Additionally, while columnar grains are mentioned, the (111) copper grain structure of nanotwinned copper is not mentioned.

[0018] The study shows that very few materials are capable of producing nanotwinned copper by electroplating, indicating that the copper deposits exhibit a high degree of nanotwinning regardless of the underlying substrate.

[0019] There remains a need in the art for copper electroplating solutions for producing nanotwinned copper deposits, particularly copper electroplating solutions capable of producing nanotwinned copper in microelectronic substrate structures and / or on substrates where (111) copper is not predominant. Summary of the Invention

[0020] It is an object of the present invention to provide an improved copper electroplating solution.

[0021] Another object of the present invention is to provide a copper electroplating solution capable of producing a high density of nanotwinned copper in the deposit.

[0022] Another object of the present invention is to provide a copper electroplating solution optimized for depositing nanotwinned copper in microelectronic substrate structures.

[0023] Yet another object of the present invention is to provide a copper electroplating solution that can initiate or produce copper deposits that exhibit high density nanotwinned copper on any surface.

[0024] Yet another object of the present invention is to provide a copper electroplating solution capable of producing deposits exhibiting a high density of nanotwinned copper on surfaces that are not dominated by (111) copper.

[0025] To that end, in one embodiment, the present invention generally relates to a copper electroplating solution, the copper electroplating solution comprising: a) a copper salt; b) a source of halide ions; and c) an inhibitor comprising the reaction product of a reactant and 2,3-epoxy-1-propanol, the reactant comprising at least one of an amine and a sulfur-containing compound; The copper electroplating solution is configured to deposit high density nanotwinned copper on the substrate.

[0026] In one embodiment, the copper electroplating solution also optionally comprises: a) an accelerator, the accelerator comprising an organosulfur compound; b) a leveling agent, the leveling agent comprising a polymeric quaternary nitrogen species.

[0027] In another embodiment, the present invention also generally relates to a method for depositing high density nanotwinned copper on a substrate comprising a surface that is not predominantly (111) copper using the copper electroplating solutions described herein. [Brief explanation of the drawings]

[0028] [Figure 1] 1 depicts SEMs of copper deposited on (111) predominant PVD copper and copper deposited on polycrystalline copper for the baseline composition and Compound 1 composition. [Figure 2] 1 depicts a 50K zoom of a nanotwinned copper transition layer deposited from Compound 1 composition on polycrystalline copper. [Figure 3] 1 depicts SEMs of copper deposited on (111) predominant PVD copper and copper deposited on polycrystalline copper for Compound 2A and Compound 2B compositions. [Figure 4] 1 depicts SEMs of copper deposited on (111)-dominant PVD copper, stainless steel, and PVD ruthenium surfaces for the baseline and Compound 1 compositions. [Figure 5] 1 depicts a 20K zoom of a nanotwinned copper transition layer deposited from Compound 2A composition according to Example 3. [Figure 6] 1 depicts a 20K zoom of a transition layer deposited from Compound 2A composition, according to Comparative Example 4. [Figure 7]1 depicts a 20K zoom of a transition layer deposited from Compound 2A composition according to Comparative Example 5. [Figure 8] 1 depicts a 20K zoom of a nanotwinned copper transition layer deposited from Compound 2A composition according to Example 6. [Figure 9] 1 depicts a 20K zoom of a nanotwinned copper transition layer deposited from Compound 2A composition according to Example 7. DETAILED DESCRIPTION OF THE INVENTION

[0029] As used herein, "a," "an," and "the" refer to both the singular and the plural, unless the context clearly dictates otherwise.

[0030] As used herein, the term "about" refers to a measurable value such as a parameter, amount, duration, etc., and is meant to include a variation of no more than + / -15%, preferably no more than + / -10%, more preferably no more than + / -5%, even more preferably no more than + / -1%, and even more preferably no more than + / -0.1% of the specifically recited value, to the extent that such variations are appropriate for practicing the invention described herein. It is also to be understood that the value referred to by the modifier "about" is itself specifically disclosed herein.

[0031] As used herein, spatially relative terms such as "beneath," "below," "lower," "above," "upper," etc. are used for ease of description to describe the relationship of one element or feature to another element or feature, as illustrated in the figures. It will be further understood that the terms "front" and "back" are not intended to be limiting and are intended to be interchangeable where appropriate.

[0032] As used herein, the terms "comprises" and / or "comprising" specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0033] As used herein, the terms "substantially free" or "essentially free" with respect to a particular element or compound, unless otherwise defined herein, mean that the given element or compound is not detectable by conventional analytical means well known to those skilled in the art of metal plating for bath analysis. Such methods typically include atomic absorption spectroscopy, titration, UV-Vis spectroscopy, secondary ion mass spectroscopy, and other commonly available analytical techniques.

[0034] As used herein, the term "structure" refers to vias, through-silicon vias (TSVs), trenches, pillars, pads, bumps, etc. that may be present on a microelectronic substrate.

[0035] As used herein, the term "high density" of nanotwinned copper refers to a copper deposit containing at least 75%, or at least 80%, or at least 85%, or at least 90%, or at least 95% nanotwinned columnar copper grains in the deposit.

[0036] All amounts are percent by weight unless otherwise specified. All numerical ranges are inclusive and combinable in any order, except where it is logical that such numerical ranges are constrained to add up to 100%. The term "average" is equivalent to the average value of a sample.

[0037] The terms "plating" and "depositing" or "deposition" are used interchangeably throughout this specification.

[0038] The terms "composition" and "bath" and "electrolyte" and "solution" are used interchangeably throughout this specification.

[0039] The term "alkyl" refers to a group consisting solely of carbon and hydrogen, unless otherwise described herein as having substituents, and has the general formula: n H 2n+1 means an organic chemical group having the formula:

[0040] Research has shown that very few materials are capable of producing nanotwinned copper (ntCu) or copper deposits that exhibit a high degree of nanotwinning. One such material is poly(2,3-epoxy-1-propanol), a linear or branched polyhydroxyl compound having a molecular weight of about 200 to about 20,000, more preferably about 500 to about 5,000, and even more preferably about 1,000 to about 3,000.

[0041] The introduction of other organic electroplating compounds, such as accelerators, brighteners, carriers, wetting agents, and / or leveling agents, has also been thought to interfere with the ability of polyhydroxyl compounds to produce nanotwinned copper.

[0042] Currently, achieving high density nanotwinned copper using polyhydroxyl compounds such as those described in U.S. Pat. No. 11,384,446 and WO 2023 / 014524 to Richardson et al., the entire subject matter of each of which is incorporated herein by reference, is very difficult unless the deposition is performed on a PVD copper seed layer that exhibits abundant copper in a (111) oriented grain structure.

[0043] For example, it is desirable to initiate high density nanotwinned copper deposition on other surfaces, including polycrystalline copper seed layers, stainless steel, and PVD ruthenium surfaces. To that end, the present inventors have investigated means to optimize copper electroplating solutions for depositing nanotwinned copper on a variety of surfaces, including, by way of example and not limitation, polycrystalline copper seed layers, stainless steel, and PVD ruthenium.

[0044] In one embodiment, the present invention generally relates to the electrodeposition of nanotwinned copper and copper electroplating solutions configured to produce copper deposits exhibiting high densities of nanotwinned copper on various surfaces.

[0045] In one embodiment, the copper electroplating solution comprises: a) a copper salt; b) a source of halide ions; and c) an inhibitor comprising the reaction product of a reactant and 2,3-epoxy-1-propanol, the reactant comprising at least one of an amine and a sulfur-containing compound.

[0046] In one embodiment, the copper electrolyte also optionally comprises: a) an accelerator, the accelerator comprising an organosulfur compound; b) a leveling agent, the leveling agent comprising a polymeric quaternary nitrogen species.

[0047] In a preferred embodiment, the copper salt comprises copper sulfate. Other copper salts that can be used in the composition include copper methanesulfonate, copper pyrophosphate, copper propanesulfonate, and other similar compounds. The concentration of copper sulfate in the electroplating solution is generally in the range of about 1 to about 100 g / L, more preferably in the range of about 20 to about 80 g / L, and more preferably in the range of about 40 to about 60 g / L.

[0048] The halide ions act as bridges to aid in the adsorption of certain organic additives onto the substrate surface. Halide ions include, but are not limited to, chloride ions, bromide ions, iodide ions, and combinations thereof. In one embodiment, the halide ions include chloride ions. The concentration of chloride ions in the electroplating solution is generally within the range of about 1 to 150 mg / L, more preferably about 30 to 120 mg / L, and most preferably about 45 to 75 mg / L.

[0049] In one embodiment, the electroplating composition contains an acid to control the conductivity of the plating bath, and suitable acids include sulfuric acid and methanesulfonic acid. In one embodiment, the acid is sulfuric acid. The concentration of the acid in the electroplating solution is generally in the range of about 0 to about 240 g / L, more preferably in the range of about 10 to about 180 g / L, and more preferably in the range of about 80 to about 140 g / L. In one embodiment, the acid concentration is in the range of about 8 to about 15 g / L, and more preferably about 10 g / L. The present inventors surprisingly discovered that the acid concentration can have a profound effect on the ability to develop nanotwinning, and that compositions containing lower acid concentrations tend to be much more permissive of ntCu formation than similar compositions containing higher acid concentrations.

[0050] In one embodiment, the inhibitor comprises the reaction product of an amine or sulfur-containing compound with 2,3-epoxy-1-propanol. The resulting linear or branched polyhydroxyl generally has a molecular weight of about 200 to about 20,000 g / mol, more preferably about 500 to about 5,000 g / mol, and most preferably about 1,000 to about 3,000 g / mol.

[0051] Examples of suitable amines include ethanolamine, diethanolamine, triethanolamine, propanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-propyldiethanolamine, methylmonoethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, N-propylmonoethanolamine, N-propyldiethanolamine, N-butylethanolamine, N-butyldiethanolamine, N,N-dibutylethanolamine, hydroxyethylmorpholine, 2-piperidinoethanol, diethanolisopropanolamine, and the like. amine, N-(2-hydroxyethyl)pyrrolidine, 4-pyridinemethanol, 4-pyridineethanol, 4-pyridinepropanol, 2-hydroxy-4-methylpyridine, 2-hydroxymethyl-1-methylimidazole, 4-hydroxymethyl-5-methylimidazole, choline chloride, b-methylcholine chloride, bis(2-hydroxyethyl)dimethylammonium chloride, tris(2-hydroxyethyl)methylammonium chloride, carnitine chloride, (2-hydroxyethyl)dimethyl(3-sulfopropyl)ammonium chloride, 1-(2-hydroxyethyl)-3-methylimidazolium chloride, and combinations of the foregoing.

[0052] Other amines include tertiary amines such as 3-hydroxypropyldimethylamine, n-butyldimethylamine, di(3-hydroxypropyl)methylamine, 2,3-dihydroxypropyldimethylamine, 3-hydroxypropyldiethylamine, 2-hydroxypropyldimethylamine, 4-hydroxybutyldimethylamine, 2-hydroxyethyldimethylamine, n-propyldimethylamine, 2-hydroxyethoxyethyldimethylamine, di(2-hydroxyethyl)methylamine, benzyldimethylamine, and 4-hydroxybenzyl Examples of suitable amines include dimethylamine, 4-methylpyridine, 3-ethylpyridine, 4-propylpyridine, 4-tert-butylpyridine, 4-cyanopyridine, 4-isopropylpyridine, 4-methoxypyridine, 3,4-lutidine, 3-methoxypyridine, and 4-pyridinemethanol, 2-dimethylamino-1-ethanol, n-butyldimethylamine, and N,N-dimethylbenzylamine, 4-ethylpyridine, and 1-methylimidazole, 1-benzylimidazole, N-methylmorpholine, and 2-[2-(dimethylamino)ethoxy]ethanol.

[0053] Another suitable amine compound is bis(2-hydroxyethyl)dimethylammonium chloride.

[0054] Other similar amine compounds capable of reacting with 2,3-epoxy-1-propanol to form reactive compounds can also be used as suppressors in the present invention. Importantly, the reactive compounds, when used in a copper electroplating solution in a suitable composition, are capable of and / or configured to initiate copper deposition with high density nanotwinned copper on a variety of substrates, including surfaces where (111) copper is not predominant.

[0055] Examples of suitable sulfur compounds include, but are not limited to, thioglycolic acid, thiomalic acid, sodium hydrogen sulfide, thiodiglycolic acid, thiodiethylene glycol, thiourea, N,N,N'N'-tetramethylthiourea, 2-mercaptoethanol, 3-mercaptopropanol, 2-mercaptoimidazole, 2-mercaptopyridine, 4-mercaptopyridine, 4-mercaptophenol, 3-mercapto-1-propanesulfonic acid, 3,6-dithia-1,8-octanediol, 2,2'-thiodiethanethiol, 2-hydroxyethyl disulfide, 3,3'-thiodipropanol, and 2,2'-(ethylenedioxy)diethanethiol.

[0056] Other reactants that can be used in copper electrolytes to initiate copper deposition with a high density of nanotwinned copper on substrates that are not predominantly (111) copper include various pyridines and imidazoles. Again, such pyridines and / or imidazoles, when used in a copper electroplating solution in a suitable composition, should be capable of and / or configured to initiate copper deposition with a high density of nanotwinned copper on a variety of substrates, including substrates that are not predominantly (111) copper.

[0057] In one embodiment, a combination of reactants such as an amine and a sulfur-containing compound is used, and the combination of reactants is reacted with 2,3-epoxy-1-propanol. For example, the inhibitor can include the reaction product of bis(2-hydroxyethyl)dimethylammonium chloride and 2,2'-thiodiethanol with 2,3-epoxy-1-propanol.

[0058] In one embodiment, the inhibitor compound comprises 90.0 to 99.9 wt. % 2,3-epoxy-1-propanol and 0.1 to 10.0 wt. % of one or more reactants, more preferably 95.0 to 99.5 wt. % 2,3-epoxy-1-propanol and 0.5 to 5.0 wt. % of one or more reactants, more preferably 97.0 to 99.0 wt. % 2,3-epoxy-1-propanol and 2.0 to 3.0 wt. % of one or more reactants.

[0059] In one embodiment, the concentration of the linear or branched polyhydroxyl suppressor compound in the copper electroplating solution is in the range of from about 1 to about 10,000 mg / L, more preferably from about 10 to about 1,000 mg / L, more preferably from about 50 to about 600 mg / L, and more preferably from about 300 to about 500 mg / L.

[0060] In some embodiments, the copper electroplating solution may optionally include an accelerator and / or a leveler.

[0061] If used, the accelerator may comprise an organic sulfur compound, including, for example, an organic sulfur salt. Suitable organic sulfur compounds include, but are not limited to, bis-(3-sulfopropyl)-disulfide (SPS), 3-mercapto-1-propanesulfonic acid (MPS), 3-(benzothizolyl-2-mercapto)-propylsulfonic acid (ZPS), N,N-dimethyldithiocarbamylpropylsulfonic acid (DPS), 3-S-isothiuronium propylsulfonate (UPS), and (O-ethyldithiocarbonato)-S-(3-sulfopropyl)ester (OPX).

[0062] In one embodiment, the accelerator comprises ZPS or UPS, hi another embodiment, the accelerator consists solely of ZPS and / or UPS, and the copper electrolyte is at least substantially free of any higher strength accelerators such as MPS or SPS.

[0063] The concentration of the accelerator depends in part on the specific accelerator used in the copper electroplating solution; weaker accelerators may be used at higher concentrations than stronger accelerators. For example, ZPS and UPS may be used in copper electroplating solutions at higher concentrations than SPS. In addition, the use of stronger accelerators, such as SPS, as accelerators may also require that a high-density nanotwinned copper deposit be applied as a base layer before subsequent layers are deposited using a copper electroplating solution containing SPS. The accelerator concentration is preferably less than about 10 mg / L, more preferably in the range of about 1 to about 8 mg / L, or in the range of about 1 to about 3 mg / L, depending in part on the specific suppressor and accelerator combination.

[0064] When used, leveler compounds include polymeric quaternary nitrogen species such as those described in WO 2018 / 057590, U.S. Pat. Nos. 10,519,557, and 10,294,574, the entire subject matter of each of which is incorporated herein by reference. Other leveler compounds include dipyridyl levelers such as those described in U.S. Pat. No. 7,303,992 and U.S. Patent Application Publication No. 2005 / 0045488, the entire subject matter of each of which is incorporated herein by reference.

[0065] For example, the leveling agent may comprise the reaction product of an aliphatic di(t-amine) and a difunctional alkylating agent corresponding to the formula:

[0066] [ka] where G is a single covalent bond, -O-, O-((A) r -O) s -, and -((A) r -O) s -, and A is selected from the group consisting of the structure -CR 3 R 4 - or -C(R 3 )(R 4 )C(R 33 )(R 34)-, each of p and r is independently an integer of 1 to 6, s is an integer of 1 to 10, q is an integer of 0 to 6, and R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , and R 34 are each independently selected from the group consisting of hydrogen and substituted or unsubstituted aliphatic hydrocarbyls containing 1 to 4 carbon atoms; R 33 is a substituted or unsubstituted aliphatic hydrocarbyl having 1 to 4 carbon atoms; Y is a leaving group selected from the group consisting of chloride, bromide, iodide, tosyl, triflate, sulfonate, mesylate, methosulfate, fluorosulfonate, methyl tosylate, and brosylate; and Z is R 30 and leaving groups independently selected from the same group as Y; 30 is selected from the group consisting of aliphatic hydrocarbyl, hydroxyl, alkoxy, cyano, carboxyl, alkoxycarbonyl, and amido; and when -G- is other than a single covalent bond, q is at least 1.

[0067] The leveling agent may also comprise an oligomeric and / or polymeric compound selected from the group consisting of salts comprising a cation having the following structure:

[0068] [ka] wherein G and A are as defined above, and B has the structure:

[0069] [ka] D has the following structure:

[0070] [ka]

[0071] [ka] is the t-amine moiety, -(CR 1 R 2 ) p -G-(CR 5 R 6 ) q ]-, which is a residue of an N,N'-dialkylheterocyclic diamine forming a di(quaternary ammonium) cation structure; p, r, t, u, w, and y are each an integer from 1 to 6; q, v, x, k, and z are each independently an integer from 0 to 6; s is an integer from 1 to 10; when v or x is other than 0, k is at least 1; when G is other than a single covalent bond, q is at least 1; and R 1 ~R 6 , R 9 ~R 19 , R 23 , R 25 , and R 34 are each independently selected from the group consisting of hydrogen or lower alkyl containing 1 to 4 carbon atoms; R 7 , R 8 , R 20 , R 21 , R 22 , R 24 , and R 33 are each independently selected from the group consisting of substituted or unsubstituted aliphatic hydrocarbyls having 1 to 4 carbon atoms; n is about 1 to about 30.

[0072] The leveling agent may also include a compound corresponding to the formula:

[0073] [ka] wherein G, A, B, and D are as defined above;

[0074] [ka] is the t-amine moiety, -(CR 1 R 2 ) p -G-(CR 5 R 6 ) q each of p, r, t, u, w, and y is an integer from 1 to 6; each of q, v, x, k, and z is independently an integer from 0 to 6; s is an integer from 1 to 10; when v or x is other than 0, k is at least 1; when G is other than a single covalent bond, q is at least 1; 1 ~R 6 , R 9 ~R 19 , R 23 , R 25 , and R 34 are each independently selected from the group consisting of hydrogen or lower alkyl containing 1 to 4 carbon atoms; R 7 , R 8 , R 20 , R 21 , R 22 , R 24 , and R 33 are each independently selected from the group consisting of substituted or unsubstituted aliphatic hydrocarbyls having 1 to 4 carbon atoms; R 30 is selected from the group consisting of aliphatic hydrocarbyl, hydroxyl, alkoxy, cyano, carboxyl, alkoxycarbonyl, and amido.

[0075] The leveling agent may also include a quaternized poly(epihalohydrin) containing n repeating units corresponding to Structure 1N and p repeating units corresponding to Structure 1P.

[0076] [ka] wherein Q has a structure corresponding to that obtainable by reacting the pendant methylene halide groups of a poly(epihalohydrin) with a tertiary amine selected from the group consisting of: (i) NR1 R 2 R 3 , where R 1 , R 2 , and R 3 are each independently selected from the group consisting of substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloaliphatic compounds, substituted or unsubstituted aralkyl, substituted or unsubstituted aryl, and substituted or unsubstituted heterocyclic compounds; (ii) N-substituted and optionally further substituted heterocycloaliphatic amines, where the N-substituent is selected from the group consisting of substituted or unsubstituted alkyl, substituted or unsubstituted cycloaliphatic compounds, substituted or unsubstituted aralkyl, substituted or unsubstituted aryl, and substituted or unsubstituted heterocyclic compounds; and (iii) substituted or unsubstituted nitrogen-containing heteroaryl compounds, n is an integer from 3 to 35, and p is an integer from 0 to 25, X is a halo substituent; X - is a monovalent anion.

[0077] Preferably, Q corresponds to structure IIA, IIB, or IIC.

[0078] [ka] wherein (i) structure IIB is an N-substituted heterocyclic moiety, (ii) structure IIC is a heterocyclic moiety, and (iii) R 1 , R 2 , R 3 , and R 4 each is independently selected from the group consisting of substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aralkyl, substituted or unsubstituted alicyclic, substituted or unsubstituted aryl, and substituted or unsubstituted heterocyclic; and (iv) R 5 , R 6 , R 7 , R 8 , and R 9Each of R is independently selected from the group consisting of hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aralkyl, substituted or unsubstituted alicyclic, substituted or unsubstituted aryl, and substituted or unsubstituted heterocyclic. 1 ~R 8 When any of are substituted, the substituents preferably do not include amino groups.

[0079] The leveling agent may also include a substituted pyridyl compound, which may be, for example, a pyridinium compound, particularly a quaternized pyridinium salt. Examples of these substituted pyridyl compounds include, but are not limited to, vinylpyridine derivatives (e.g., 2-vinylpyridine derivatives and 4-vinylpyridine derivatives), vinylpyridine homopolymers, vinylpyridine copolymers, quaternized vinylpyridine salts, and quaternized salts of these homopolymers and copolymers. Specific examples of such compounds include poly(4-vinylpyridine), a reaction product of poly(4-vinylpyridine) and dimethyl sulfate, a reaction product of 4-vinylpyridine and 2-chloroethanol, a reaction product of 4-vinylpyridine and benzyl chloride, a reaction product of 4-vinylpyridine and allyl chloride, a reaction product of 4-vinylpyridine and 4-chloromethylpyridine, a reaction product of 4-vinylpyridine and 1,3-propane sultone, a reaction product of 4-vinylpyridine and methyl tosylate, a reaction product of 4-vinylpyridine and chloroacetone, a reaction product of 4-vinylpyridine and 2-methoxyethoxymethyl chloride, a reaction product of 4-vinylpyridine and 2-chloroethyl ether, a reaction product of 2-vinylpyridine and methyl tosylate, a reaction product of 2-vinylpyridine and dimethyl sulfate, a reaction product of vinylpyridine and a water-soluble initiator, poly(2-methyl-5-vinylpyridine), and 1-methyl-4-vinylpyridinium trifluoromethylsulfonate.

[0080] Other polymeric quaternary nitrogen species may also be used as leveling agents in the copper electroplating compositions described herein, so long as they are compatible with the suppressors (and accelerators) and do not impair their ability to initiate nanotwinned copper deposition on a variety of substrates.

[0081] In one embodiment, suitable leveling agent species include, but are not limited to, the reaction product of 4,4-dipyridyl and 2-chloroethyl ether. The concentration of the leveling agent will depend, in part, on the particular leveling agent used, as well as the particular suppressors and accelerators, and process conditions. In one embodiment, the leveling agent is present in the copper electrolyte at a concentration in the range of less than about 10 mg / L, or in the range of about 0.5 to about 10 mg / L, more preferably in the range of about 2 to about 5 mg / L.

[0082] Higher current densities (i.e., in the range of about 3 to about 6 ASD, more preferably about 3 to about 5 ASD) have been found to be beneficial for the purpose of producing nanotwinned copper. However, for superloading copper within microelectronic substrate structures, lower current densities, such as in the range of about 0.5 to about 2 ASD, are preferred.

[0083] Thus, in one embodiment, the copper electroplating composition comprises a two- or three-component copper electroplating bath used in a step current plating process to enable nanotwinned copper microstructure via fill. In one embodiment, a two-component copper electroplating bath may be used that includes a suppressor compound as described herein and a leveling agent comprising a polymeric quaternary nitrogen species as described above. In another embodiment, a three-component copper electroplating bath may be used that includes a suppressor compound as described herein, an accelerator comprising an organosulfur compound, preferably a UPS, and a leveling agent comprising a polymeric quaternary nitrogen species.

[0084] A ramped current, in which the current ramps from high to low, as opposed to a step current change, can also be applied to two-component and three-component copper plating baths to achieve via fill with nanotwinned copper microstructures.

[0085] As described herein, in one embodiment, the copper electroplating solution comprises: A) about 40 to about 60 g / L of copper ions, B) about 80 to about 140 g / L of sulfuric acid; C) about 30 to about 120 mg / L of chloride ions; D) about 300 to about 500 mg / L of a reaction product of an amine or sulfur-containing compound with 2,3-epoxy-1-propanol; E) optionally about 0.5 to about 10 mg / L of a leveling agent, the leveling agent comprising a polymeric quaternary nitrogen species; F) optionally about 1 to about 50 mg / L of an accelerator, the accelerator comprising an organic sulfur compound.

[0086] In another preferred embodiment, the copper electroplating solution comprises: A) about 40 to about 60 g / L of copper ions, B) about 80 to about 140 g / L of sulfuric acid; C) about 30 to about 120 mg / L of chloride ions; D) about 300 to about 500 mg / L of a reaction product of an amine or sulfur-containing compound with 2,3-epoxy-1-propanol; E) about 0.0 to about 10 mg / L of a leveling agent, the leveling agent comprising a polymeric quaternary nitrogen species.

[0087] In another preferred embodiment, the copper electroplating solution comprises: A) about 40 to about 60 g / L of copper ions, B) about 80 to about 140 g / L of sulfuric acid; C) about 30 to about 120 mg / L of chloride ions; D) about 300 to about 500 mg / L of a reaction product of an amine or sulfur-containing compound with 2,3-epoxy-1-propanol; E) about 0.5 to about 10 mg / L of a leveling agent, the leveling agent comprising a polymeric quaternary nitrogen species; F) about 0.0 to about 50 mg / L of an accelerator, the accelerator comprising an organic sulfur compound.

[0088] In another embodiment, the copper electrolyte of the present invention contains a lower amount of sulfuric acid. For example, the copper electrolyte contains: A) about 5 to about 50 g / L of copper ions; B) about 8 to about 15 g / L of sulfuric acid; C) about 30 to about 120 mg / L of chloride ions; D) about 300 to about 500 mg / L of a reaction product of an amine or sulfur-containing compound with 2,3-epoxy-1-propanol; E) optionally about 0.5 to about 10 mg / L of a leveling agent, the leveling agent comprising a polymeric quaternary nitrogen species; F) optionally about 1 to about 50 mg / L of an accelerator, the accelerator comprising an organic sulfur compound.

[0089] In another preferred embodiment, the copper electroplating solution comprises: A) about 5 to about 50 g / L of copper ions; B) about 8 to about 15 g / L of sulfuric acid; C) about 30 to about 120 mg / L of chloride ions; D) about 300 to about 500 mg / L of a reaction product of an amine or sulfur-containing compound with 2,3-epoxy-1-propanol; E) about 0.0 to about 5 mg / L of a leveling agent, the leveling agent comprising a polymeric quaternary nitrogen species.

[0090] In another preferred embodiment, the copper electroplating solution comprises: A) about 5 to about 50 g / L of copper ions; B) about 8 to about 15 g / L of sulfuric acid; C) about 30 to about 120 mg / L of chloride ions; D) about 300 to about 500 mg / L of a reaction product of an amine or sulfur-containing compound with 2,3-epoxy-1-propanol; E) about 0.0 to about 5 mg / L of a leveling agent, the leveling agent comprising a polymeric quaternary nitrogen species; F) about 0.0 to about 50 mg / L of an accelerator, the accelerator comprising an organic sulfur compound.

[0091] By "consisting essentially of" it is meant that the composition does not contain any additives that would adversely affect the ability of the composition to initiate copper deposition having a high density of nanotwinned copper on a substrate, including substrates that are non-(111) copper substrates.

[0092] The present invention also generally provides a method for electroplating nanotwinned copper onto a substrate, comprising: The method comprises: A) providing a substrate, at least one anode, and a copper plating bath described herein; B) contacting the substrate and at least one anode with a copper bath, respectively; C) applying a voltage between the surface of the workpiece and at least one anode such that a cathodic polarity is imposed on the substrate relative to the at least one anode; The present invention relates to a method in which a copper structure having a high density of nanotwin crystals is deposited on a substrate.

[0093] The current density is generally in the range of about 0.01 to about 50 ASD, more preferably about 0.5 to about 20 ASD, and most preferably about 1 to about 10 ASD. In addition, the electroplating solution is preferably stirred, and the electroplating solution is generally mixed at about 1 to about 2,500 rpm, more preferably about 10 to about 1,200 rpm, and most preferably about 50 to about 400 rpm.

[0094] The anode can be an insoluble or a soluble anode, with an insoluble anode being preferred.

[0095] Copper is electrodeposited for a period of time to initiate nanotwinned copper deposition to a thickness of about 0.1 to about 1,000 μm, more preferably about 0.3 to about 200 μm, and most preferably about 1 to about 100 μm.

[0096] Substrates that can be plated with the copper electroplating solutions described herein include printed wiring boards (PWBs), printed circuit boards (PCBs), and other electronic substrates that may contain one or more pillars, pads, lines, and vias, including surfaces that are non-(111) copper, such as polycrystalline copper seed layers, stainless steel, and PVD ruthenium.

[0097] The presence of nanotwinned grain structure can be observed using any suitable microscopy technique, such as electron microscopy. The amount of nanotwinned grain structure in the copper deposit is preferably greater than about 80%, more preferably greater than about 90% of the nanotwinned columnar copper grains, as estimated based on SEM cross sections.

[0098] As described in the examples below, a nanotwinned copper structure can be characterized by a plurality of (111)-oriented crystalline copper grains containing a majority of nanotwinning. In some implementations, the plurality of (111)-oriented crystalline copper grains contains a high density of nanotwinning. As used herein, "high density of nanotwinning" can refer to a copper structure having more than about 80% nanotwinning, or even more than about 90% nanotwinning, as observed using suitable microscopy techniques.

[0099] The crystal orientation of the copper grains can be characterized using suitable techniques such as electron backscatter diffraction (EBSD) analysis. In some implementations, the crystal orientation map can be shown as an inverse pole figure (IPF) map. According to the present invention, preferably, the nanotwinned copper structure contains predominantly (111) oriented grains.

[0100] The following inhibitor compounds were used in the examples:

[0101] Compound 1: Reaction product of 4-pyridinemethanol (1 wt %) with 2,3-epoxy-1-propanol (99 wt %) to produce a polymer.

[0102] Compound 2A: 1 wt % bis(2-hydroxyethyl)dimethylammonium chloride was reacted with 99 wt % 2,3-epoxy-1-propanol to produce a polymer.

[0103] Compound 2B: 1 wt % bis(2-hydroxyethyl)dimethylammonium chloride and 1 wt % 2,2′-thiodiethanol were reacted with 98 wt % 2,3-epoxy-1-propanol to produce a polymer.

[0104] The inhibitor compounds were prepared by reacting an amine or sulfur-containing compound with 2,3-epoxy-1-propanol. The general reaction procedure is as follows:

[0105] A solution of boron trifluoride etherate (5 mmol) in methanol was added dropwise to a solution of the listed weight percent of 2,3-epoxy-1-propanol and amine or sulfur-containing compound in a 1 L round-bottom flask equipped with a thermometer, reflux condenser, and magnetic stirrer to produce Compound 1, Compound 2A, and Compound 2B, respectively. The temperature was allowed to rise freely during the exotherm and heated at the maximum temperature for 30 minutes. Water was then added to cool the reaction to below 100°C to produce a 20% w / w solution, which was continued to stir for 4 hours. The solution was then filtered and used as is.

[0106] Example 1: A copper electrolyte containing a solution of 40 g / L copper(II) ions, 10 g / L sulfuric acid, 50 mg / L chloride ions, and 400 mg / L amine-based polyhydroxyl inhibitor (baseline composition) was prepared, and a second copper electrolyte was prepared in the same manner as the baseline composition (composition with Compound 1), except that 400 mg / L of Compound 1 was substituted.

[0107] Using two electrolytes, intermediate nanotwinned copper deposition was initiated from a (111)-dominant PVD copper seed and a polycrystalline copper seed at a constant current of 1 ASD.

[0108] As can be seen from Figure 1, both solutions were able to produce intermediate nanotwinned copper from the (111) dominant copper seeds, but the baseline composition was unable to produce any nanotwinned copper on the polycrystalline copper seed layer, while the Compound 1 composition was able to produce intermediate nanotwinned copper from the polycrystalline copper seeds.

[0109] Figure 2 depicts a 50K zoom of the transition layer of the Compound 1 composition plated onto a polycrystalline copper seed. As can be seen in Figure 2, the Compound 1 composition was able to produce ntCu from the polycrystalline copper seed after 111 nm deposition to a total thickness of approximately 2.8 μm.

[0110] As can be seen in FIG. 4, the Compound 1 composition was able to produce a vast majority of nanotwinned copper crystals from the stainless steel and ruthenium substrates, whereas the baseline composition was unable to do so.

[0111] Example 2: A copper electrolyte containing a solution of 40 g / L copper(II) ions, 10 g / L sulfuric acid, 50 mg / L chloride ions, and 400 mg / L Compound 2A was prepared, and a second copper electrolyte was prepared in the same manner except that 400 mg / L Compound 2B was substituted.

[0112] Using two electrolytes, intermediate nanotwinned copper deposition was initiated from a (111)-dominant PVD copper seed and a polycrystalline copper seed at a constant current of 1 ASD.

[0113] As can be seen from Figure 3 , both solutions were able to produce intermediate nanotwinned copper from (111)-dominant copper seeds, but the addition of a thiol compound in addition to an amine and reacting both of these with 2,3-epoxy-1-propanol improved the ability of nanotwinned copper on non-(111) Cu substrates.

[0114] As can be seen from Examples 1 and 2, the use of the above-described suppressor, comprising the reaction product of an amine or sulfur-containing compound with 2,3-epoxy-1-propanol, in a copper electroplating solution enables the copper electroplating solution to initiate high-density nanotwinned copper deposition on a variety of substrates, including non-(111) copper substrates, and to produce nanotwinned copper within the structure of the substrate.

[0115] Example 3: A copper electrolyte was prepared containing 40 g / L copper(II) ions, 10 g / L sulfuric acid, 50 mg / L chloride ions, 1 mg / L SPS, and 400 mg / L compound 2A. Blanket coupons with a (111)-dominant PVD copper seed layer were plated with 3ASD and produced >90% nanotwinned copper.

[0116] Figure 5 depicts a 20K zoom of a transition layer of the Compound 2A composition plated onto a (111)-dominant PVD copper seed layer. As can be seen in Figure 5, the Compound 2A composition was able to produce ntCu from the (111)-dominant PVD copper seed.

[0117] Example 3A: Copper electrolyte was prepared in the same manner as in Example 3, except that 3 mg / L of SPS was added to the solution. Blanket coupons with a (111)-dominant PVD copper seed layer were plated with 3ASD and produced >90% nanotwinned copper.

[0118] Example 3B: Copper electrolyte was prepared in the same manner as in Example 3, except that 8 mg / L of SPS was added to the solution and Compound 1 was used instead of Compound 2A. Blanket coupons with a (111)-dominant PVD copper seed layer were plated with 3ASD and produced >90% nanotwinned copper.

[0119] Example 3C: Additional copper electrolytes were prepared in the same manner as in Example 3, except that 8 mg / L of SPS was added to the solution and Compound 2B was used instead of Compound 2A. Blanket coupons with a (111)-dominant PVD copper seed layer were plated with 3ASD and produced >90% nanotwinned copper.

[0120] Comparative Example 4: Copper electrolyte was prepared in the same manner as in Example 3, except that 28 mg / L of SPS was added to the solution. Blanket coupons with a (111)-dominant PVD copper seed layer were plated with 3ASD and did not produce nanotwinned copper.

[0121] Figure 6 depicts a 20K zoom of a transition layer of the Compound 2A composition plated onto a (111)-dominant PVD copper seed layer. As can be seen in Figure 6, the Compound 2A composition was unable to produce ntCu from the (111)-dominant PVD copper seed.

[0122] As can be seen from Comparative Example 4, increasing the amount of SPS in the copper electroplating solution from 1 to 28 mg / L caused a loss in nanotwinned copper.

[0123] Comparative Example 5: The copper electrolyte was prepared in the same manner as in Example 3, except that 50 g / L of copper(II) ions and 100 g / L of sulfuric acid were added to the solution. Blanket coupons with a (111)-dominant PVD copper seed layer were plated with 3ASD and did not produce nanotwinned copper.

[0124] Figure 7 depicts a 20K zoom of a transition layer of the Compound 2A composition plated onto a (111)-dominant PVD copper seed layer. As can be seen in Figure 7, the Compound 2A composition was unable to produce ntCu from the (111)-dominant PVD copper seed.

[0125] As can be seen from Comparative Example 5, increasing the amount of sulfuric acid in the copper electroplating solution from 10 to 100 g / L caused a loss in nanotwinned copper.

[0126] Example 6: A copper electrolyte containing 40 g / L copper(II) ions, 10 g / L sulfuric acid, 50 mg / L chloride ions, 1 mg / L SPS, 400 mg / L Compound 2A, and 3 mg / L leveling agent was prepared. Blanket coupons with a (111)-dominant PVD copper seed layer were plated with 3ASD and produced >90% nanotwinned copper.

[0127] Figure 8 depicts a 20K zoom of a transition layer of the Compound 2A composition plated onto a (111)-dominant PVD copper seed layer. As can be seen in Figure 8, the Compound 2A composition was able to produce ntCu from the (111)-dominant PVD copper seed.

[0128] Example 7: Copper electrolyte was prepared in the same manner as in Comparative Example 4, except that 3 mg / L of leveling agent was added to the solution. Blanket coupons with a (111)-dominant PVD copper seed layer were plated with 3ASD and produced >90% nanotwinned copper.

[0129] Figure 9 depicts a 20K zoom of a transition layer of the Compound 2A composition plated onto a (111)-dominant PVD copper seed layer. As can be seen in Figure 9, the composition was able to produce ntCu from the (111)-dominant PVD copper seed.

[0130] As can be seen from Example 7, even with high concentrations of accelerators, when used in combination with low concentrations of sulfuric acid and the addition of leveling agents, >90% nanotwinned copper can be produced.

[0131] Finally, it should also be understood that the following claims, as language may vary, are intended to cover all of the general and specific features of the invention described herein, and all statements of the scope of the invention.

Claims

1. 1. A copper electroplating solution comprising: a) a copper salt; b) a source of halide ions; and c) an inhibitor comprising the reaction product of a reactant and 2,3-epoxy-1-propanol, the reactant comprising at least one of an amine and a sulfur-containing compound; 1. A copper electroplating solution, wherein the copper electrolyte is capable of depositing copper, and wherein the copper deposit exhibits greater than about 80% nanotwinned columnar copper grains.

2. 10. The copper electroplating solution of claim 1, wherein the copper salt is copper sulfate.

3. 3. The copper electroplating solution of claim 1 or 2, further comprising an acid, said acid comprising sulfuric acid or methanesulfonic acid.

4. the copper electroplating composition comprising: (i) an accelerator, the accelerator comprising an organosulfur compound; (ii) a leveling agent, the leveling agent comprising a polymeric quaternary nitrogen species.

5. The reactants may be selected from the group consisting of ethanolamine, diethanolamine, triethanolamine, propanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-propyldiethanolamine, methylmonoethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, N-propylmonoethanolamine, N-propyldiethanolamine, N-butylethanolamine, N-butyldiethanolamine, N,N-dibutylethanolamine, hydroxyethylmorpholine, 2-piperidinoethanol, diethanolisopropanolamine, N-(2-hydroxyethyl)pyrrolidine, 4-pyridinemethanol ...

5. The copper electroplating solution of claim 1, comprising an amine compound selected from the group consisting of 2-pyridineethanol, 4-pyridinepropanol, 2-hydroxy-4-methylpyridine, 2-hydroxymethyl-1-methylimidazole, 4-hydroxymethyl-5-methylimidazole, choline chloride, b-methylcholine chloride, bis(2-hydroxyethyl)dimethylammonium chloride, tris(2-hydroxyethyl)methylammonium chloride, carnitine chloride, (2-hydroxyethyl)dimethyl(3-sulfopropyl)ammonium chloride, 1-(2-hydroxyethyl)-3-methylimidazolium chloride, bis(2-hydroxyethyl)dimethylammonium chloride, and combinations of the foregoing.

6. 5. The copper electroplating solution of claim 1, wherein the reactants comprise a sulfur-containing compound selected from the group consisting of 2,2'-thiodiethanol, thioglycolic acid, thiomalic acid, sodium hydrogen sulfide, thiodiglycolic acid, thiodiethylene glycol, thiourea, N,N,N',N'-tetramethylthiourea, 2-mercaptoethanol, 3-mercaptopropanol, 2-mercaptoimidazole, 2-mercaptopyridine, 4-mercaptopyridine, 4-mercaptophenol, 3-mercapto-1-propanesulfonic acid, 3,6-dithia-1,8-octanediol, 2,2'-thiodiethanethiol, 2-hydroxyethyl disulfide, 3,3'-thiodipropanol, 2,2'-(ethylenedioxy)diethanethiol, and combinations of one or more of the foregoing.

7. The copper electroplating solution of claim 6, wherein the sulfur-containing compound comprises 2,2'-thiodiethanol.

8. 5. The copper electroplating solution of claim 4, wherein the accelerator is present and is selected from the group consisting of bis-(3-sulfopropyl)-disulfide, 3-mercapto-1-propanesulfonic acid, 3-(benzothizolyl-2-mercapto)-propylsulfonic acid, N,N-dimethyldithiocarbamylpropylsulfonic acid, 3-S-isothiuronium propylsulfonate, and (O-ethyldithiocarbonato)-S-(3-sulfopropyl)ester.

9. The copper electroplating solution of claim 4 , wherein both the accelerator and the leveler are present in the composition.

10. 5. The copper electroplating solution of claim 1, wherein the suppressor comprises 90.0 to 99.9 wt. % of the 2,3-epoxy-1-propanol reacted with 0.1 to 10.0 wt. % of the reactants, or the suppressor comprises 95.0 to 99.5 wt. % of 2,3-epoxy-1-propanol reacted with 0.5 to 5.0 wt. % of the reactants, or the suppressor comprises 97.0 to 99.0 wt. % of 2,3-epoxy-1-propanol reacted with 2.0 to 3.0 wt. % of the reactants.

11. the copper electroplating solution a. about 40 to about 60 g / L of copper ions; b. about 80 to about 140 g / L of sulfuric acid; c. about 30 to about 120 mg / L chloride ions; d) The copper electroplating solution of claim 1, comprising about 300 to about 600 mg / L of the reaction product of an amine or sulfur-containing compound and 2,3-epoxy-1-propanol.

12. the copper electroplating solution a. about 5 to about 50 g / L of copper ions; b. about 8 to about 15 g / L of sulfuric acid; c. about 30 to about 120 mg / L chloride ions; d) The copper electroplating solution of claim 1, comprising about 300 to about 600 mg / L of the reaction product of an amine or sulfur-containing compound and 2,3-epoxy-1-propanol.

13. a. about 0.01 to about 10 mg / L of the leveling agent, wherein the leveling agent comprises a polymeric quaternary nitrogen species; or b) The copper electroplating solution of claim 12, further comprising about 0.1 to about 50 mg / L of said accelerator.

14. 10. The copper electroplating solution of claim 1, wherein the copper electroplating solution is at least substantially free of any accelerators, brighteners, carriers, wetting agents, or leveling agents, or any compounds that may function as accelerators, brighteners, carriers, wetting agents, or leveling agents.

15. 1. A method for electrodepositing copper onto a substrate, said method comprising: contacting the surface of the substrate and at least one anode with the copper electrolyte of any one of claims 1 to 4; b. applying a voltage between the surface of the substrate and the at least one anode such that a cathodic polarity is imposed on the substrate relative to the at least one anode; A copper deposition having a high density of nanotwinned columnar copper grains is initiated on the substrate.

16. 16. The method of claim 15, wherein the nanotwinned copper deposit is in a (111) orientation.

17. 17. The method of claim 15 or 16, wherein the copper deposit comprises more than 90% nanotwinned columnar copper grains.

18. The method of claim 15, wherein the substrate is a non-(111) oriented copper substrate.

19. 20. The method of claim 18, wherein the substrate is selected from the group consisting of a polycrystalline copper seed, stainless steel, and PVD ruthenium.

20. 20. The method of claim 18 or 19, wherein the nanotwinned copper deposit is in a (111) orientation.

21. A method for electrodepositing >80% nanotwinned copper on non-(111) oriented copper substrates using an aqueous copper electrolyte containing at least one organic additive.

22. 22. The method of claim 21, wherein the at least one organic additive comprises the reaction product of a reactant and 2,3-epoxy-1-propanol, the reactant comprising at least one of an amine and a sulfur-containing compound.

23. 16. The method of claim 15, wherein the voltage is applied at a current density of about 1 to about 8 ASD, more preferably about 1 to about 3 ASD.

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