Additive for metal electroplating and preparation method and application thereof
By preparing a metal plating solution containing amide group compounds as additives, the problem of uniform filling of copper in holes or grooves in copper electroplating is solved, and high-quality copper deposition and defect-free filling are achieved. It is suitable for small pore size, high-deep and aspect ratio through-silicon holes and small-size chip interconnect structures.
Patent Information
- Application Number
- CN202510774496.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-11
- Publication Date
- 2025-08-19
AI Technical Summary
In the existing copper plating process, the problem of copper being uniformly filled in holes or grooves without void defects is particularly challenging in small-aperture, high-deep-to-distance ratio through-silicon holes and small-size chip interconnect structures.
A metal plating solution is prepared by reacting with polysuccinimide in the presence of solvent using amide group-containing compounds or their protonated or quaternary ammonium salt-based products as additives. Combined with appropriate plating parameters and stirring measures, uniform deposition of copper and void-free filling are achieved.
During the copper plating process, void-free and flat surface copper deposits are formed, which improves the reliability and interconnection quality of electronic products, simplifies the plating solution formulation, reduces the amount of additives used, and reduces environmental pollution.
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Figure CN120505677A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of metal electroplating, and in particular relates to an additive for metal electroplating, a preparation method and an application thereof. Background Art
[0002] Copper electroplating is of irreplaceable importance in chip manufacturing and packaging, and is one of the key technologies for achieving high performance, high integration and miniaturization of chips. Copper electroplating is often used in processes such as Damascene plating and through-silicon via (TSV) plating to achieve high-density, high-performance electrical connections. Damascus plating is mainly used for the copper interconnect layer inside the chip, while TSV (through-silicon via) technology is a key technology in advanced packaging, used to vertically connect different chip layers. In addition, copper electroplating is also used for copper filling of blind holes, buried holes, through holes and trench structures in printed circuit boards, glass substrates, through-silicon vias and adapter boards, as well as electroplating preparation of copper pillars and micro-bumps.
[0003] During copper electroplating, ensuring uniform copper filling of holes or trenches without void defects places high demands on the electroplating process and the performance of the electroplating solution. Various additives are typically added to the electroplating solution. These additives are referred to by various names in the industry, such as suppressors, which may also be called wetting agents, dispersants, or carriers; accelerators, also known as promoters or brighteners; and levelers, often called levelers. Suppressors play a crucial role in the electroplating process, effectively suppressing excessive copper deposition. This characteristic is crucial because excessive copper deposition can prematurely seal the pattern, impacting the overall electroplating performance and interconnect quality. The main function of an accelerator is to accelerate copper deposition at the bottom of the pattern and, in doing so, refine the grain size. Accelerating copper deposition at the bottom enables more efficient pattern filling, while refined grain size improves the quality and performance of the plated layer. Levelers are also essential, helping to suppress copper deposition and creating a flat and uniform surface. During electroplating, there is often a difference in the copper deposition thickness between the interconnected pattern area and the non-patterned area. The addition of a leveler can effectively reduce this difference, creating favorable conditions for the subsequent chemical mechanical polishing (CMP) process, enabling the CMP process to proceed more smoothly, thereby obtaining a smoother, higher-quality coating surface.
[0004] Therefore, it is of great significance to prepare and develop copper plating additives and optimize the electroplating solution formula and electroplating process. Summary of the Invention
[0005] The first object of the present invention is to provide an additive (compound) for metal electroplating, which is suitable for use in a composition for metal or metal alloy deposition, preferably in a copper or copper alloy deposition composition, as a leveler and / or inhibitor.
[0006] The second object of the present invention is to provide a method for preparing an additive (compound) for metal electroplating.
[0007] The third object of the present invention is to provide the application of additives (compounds) for metal electroplating, including metal plating baths, to achieve complete filling of blind holes, buried holes, through holes and trench structures in chips, circuit boards, packaging substrates, glass substrates, through silicon vias, and adapter plates, as well as plating solution formulations and electroplating processes.
[0008] The metal electroplating additive provided by the present invention is an amide group-containing compound, the structure of which is shown in Formula 101; or a protonated product of the amide group-containing compound or a quaternary ammonium salt thereof;
[0009]
[0010] Wherein, n1 is selected from a positive real number of 1 to 200; n2 is selected from 0 or a positive real number of 0 to 200; n3 is selected from 0 or a positive real number of 0 to 200; R1 is selected from a connecting group or a direct link of an alkyl group (C1-C5) or an aryl group; R2 is selected from a nitrogen-containing group or a nitrogen-containing molecular fragment; R3 is selected from an alkyl group (C1-C5), an aryl group, or a hydrogen atom.
[0011] Further:
[0012] The R2 has a structure shown in Formula 102, Formula 103, Formula 104, or Formula 105:
[0013]
[0014] In formula 102, R 21 With R 22 are independently selected from hydrogen, alkyl (C1-C5) or aryl.
[0015] The protonated product is obtained by reacting the aforementioned amide group-containing compound with an aqueous solution of hydrochloric acid, sulfuric acid, hydrobromic acid, perchloric acid, hydroiodic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, methanesulfonic acid or trifluoroacetic acid; it can also be obtained by reacting with an acid in the plating solution.
[0016] The quaternary ammonium salt product is obtained by reacting the aforementioned amide group-containing compound with an alkylating agent, wherein the alkylating agent is selected from one or more of methyl iodide, ethyl iodide, methyl bromide, ethyl bromide, methyl chloride, ethyl chloride, benzyl chloride, dimethyl sulfate, diethyl sulfate, 1,3-propane sultone, 1,4-butane sultone, methyl p-toluenesulfonate, methyl benzenesulfonate, ethyl benzenesulfonate, ethylene oxide, propylene oxide, and epichlorohydrin.
[0017] The present invention also provides a method for preparing the above-mentioned metal electroplating additive, which is prepared by reacting polysuccinimide and a compound containing a primary amine group in the presence of a solvent to obtain a compound containing an amide group. The reaction route is:
[0018]
[0019] Wherein, n1 is a positive real number between 1 and 200, n2 is 0 or a positive real number between 0 and 200, n of polysuccinimide is the sum of n1, n2 and n3; R1, R2 and R3 in the compound containing a primary amine group are as shown above.
[0020] The solvent is one or more of the following: dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, water; the reaction is carried out under stirring; the reaction temperature is 0 to 120° C.; the reaction time is 1 to 72 hours;
[0021] After the reaction is completed, further processing includes at least one of precipitation, natural standing, rotary evaporation, beating, and recrystallization.
[0022] The metal electroplating additive is to use the amide group-containing compound, or the protonated or quaternized product of the amide group-containing compound, as an additive to the plating solution for metal electroplating;
[0023] The metal is copper, zinc, chromium, tin, nickel, cobalt, gold, silver, titanium, or an alloy thereof. The metal plating solution comprises a metal salt, water, sulfuric acid, a halogen salt, and additives. Other accelerators and inhibitors may also be added as needed.
[0024] In the metal electroplating solution, the concentration of the additive is 1 to 1000 ppm.
[0025] The metal commonly used in the present invention is copper.
[0026] In the copper electroplating solution, the copper salt is one or more of copper sulfate, copper methanesulfonate, and copper trifluoromethanesulfonate.
[0027] The halogen salt is one or more of potassium bromide, sodium bromide, potassium iodide, sodium iodide, potassium chloride, and sodium chloride.
[0028] The other accelerators described have a relatively small molecular weight and are generally adsorbed on the copper surface and the bottom of the groove, reducing the electrochemical potential and cathode polarization of the electroplating reaction, thereby accelerating the deposition rate of the position and realizing super filling of the groove. Wherein, the accelerator that can be used for the present invention includes but is not limited to organic matter and / or salt containing sulfur and its functional group, organic matter and / or salt containing disulfide bonds. Suitable accelerators include but are not limited to thiourea, allylthiourea, acetylthiourea, MES (2-morpholineethanesulfonic acid), DPS (N, N- dimethyldithiocarbamide propane sulfonate sodium), UPS (isothiourea propyl sulfate), ZPS (3- (benzothiazole-2- mercapto) -propane sulfonate sodium), SPS (polydisulfide dipropane sulfonate sodium), MPS (3- mercapto-1-propane sulfonate sodium), (O- ethyldithiocarbonic acid) -S- (3- sulfonic acid propyl) ester potassium salt. Particularly preferred accelerators are: SPS (sodium polydisulfide propane sulfonate) and MPS (sodium 3-mercapto-1-propane sulfonate).
[0029] Other inhibitors include, but are not limited to, polyethylene glycol (PEG); block copolymers of polyethylene glycol, polypropylene glycol (PPG), or both, such as the PEG and PPG triblock copolymer EPE and the nitrogen-containing PEG / PPG copolymer Te701; amines, such as ethoxylated amines, polyoxyalkylene amines, and alkanolamines; amides; and alkyl polyether sulfonates. Particularly preferred inhibitors include, but are not limited to, ethylene oxide / propylene oxide (EO / PO) block or random copolymers.
[0030] The amount of the inhibitor used can vary widely depending on the specific metal plating bath, the specific inhibitor and other additives selected, and the electroplating method selected. Typically, the inhibitor is added in an amount of 0.1 to 3000 ppm. For the present invention, an inhibitor is preferably added in an amount of 1 to 1000 ppm, with an amount of 2 to 500 ppm being particularly preferred.
[0031] The aforementioned electroplating additives function in electroplating by acting as levelers or inhibitors, combined with other inhibitors, accelerators, halogen salts, or halogen ions, to form an additive composition, which is then added to a base plating solution to form an electroplating solution. Copper metal is then electroplated using conventional electroplating equipment through a conventional electroplating process.
[0032] During the electroplating process, the cathode is the object to be plated with a metal seed layer and is connected to the negative pole of the power supply. The metal material serves as the anode and is connected to the positive pole of the power supply. The metal material includes a pure copper plate and a phosphor copper plate. During electroplating, the object to be plated with the metal seed layer is immersed in the electroplating solution while applying a certain current. Depending on the actual situation, the methods that can be adopted include immersing the object to be plated first and then applying the current, or applying the current first and then immersing the object to be plated. The specific form of applying the current can be constant current, constant potential, multi-stage current or pulse current, etc., to carry out electrodeposition. During the electroplating process, stirring, ventilation, liquid filtration and reflux measures can be applied at the same time to make the deposition more uniform. The current density and the electrode surface potential can vary within a wide range depending on the substrate to be plated. Generally speaking, the current density can be in the range of 0.01 to 10A / dm2, and the preferred current density is in the range of 0.05 to 3A / dm2. The electroplating temperature range is maintained from 18 to 35°C, and the preferred temperature range is 23 to 26°C.
[0033] The configuration of the electroplated copper and its electroplating solution, the electroplated copper electroplating solution can be used for copper filling of through silicon vias (TSVs), chips, glass substrates (TGVs), circuit boards, packaging substrates, adapter boards, buried holes, through holes and trench structures, and can also be used for the electroplating preparation of copper pillars and micro bumps.
[0034] The size specifications of the through silicon via include: aperture range is 0.5 to 100μm; depth range is: 10 to 500μm. The aspect ratio (ratio of depth to aperture) of the through silicon via includes but is not limited to: 5:1 to 20:1. The chip electroplating is used for interconnection between transistors and other components in the chip. The electroplating objects are pre-etched grooves and through holes in the chip, and the size range is different, generally ranging from tens of nanometers to hundreds of nanometers. In the TGV electroplating, the through hole diameter is usually 10 to 100μm, and the aspect ratio range is generally 4:1 to 10:1. The through silicon via, chip, glass substrate (TGV) to be plated is provided with a metal seed layer. The metal seed layer can be prepared by physical vapor deposition (PVD), chemical vapor deposition (CVD), chemical plating and other methods.
[0035] The technical features and performance advantages of the present invention mainly include:
[0036] The electroplating additive provided by this invention has a structure significantly different from traditional polyether inhibitors and does not contain ether bond fragments. The novel electroplating additive provided by this invention contains tertiary amine groups and has both leveling and inhibitory properties, helping to simplify plating bath formulations and reduce additive usage.
[0037] The polysuccinimide used in the synthesis method provided by the present invention is widely available and renewable, and can be prepared from biomass resources. Furthermore, polysuccinimide is biodegradable and can be broken down by microorganisms into relatively simple, environmentally friendly small molecules, such as carbon dioxide and water, in natural environments or under specific biodegradation conditions, without causing long-term pollution or harm to the environment.
[0038] The synthesis method of the compound provided by the present invention has the advantages of simple operation, high efficiency, energy saving, low cost, etc.
[0039] The electroplating additive is beneficial for forming a copper deposit with no voids and a flat surface in the case of copper electroplating, especially when filling through holes, blind holes, buried holes and trenches, which is beneficial for the reliability of electronic products.
[0040] It can be used in circuit board manufacturing, microelectronic chip interconnection copper plating, TSV copper interconnection, packaging interconnection structure metal deposition and other fields.
[0041] In particular, electroplating and filling of small-diameter (less than 5μm), high-aspect-ratio (5:1 or greater) through-silicon vias (TSVs) and small-size (less than 100nm) chip interconnects is crucial for achieving efficient, high-density chip interconnection. With the continuous decrease in chip integration and feature size, higher requirements are placed on defect-free filling of chip internal interconnect structures (vias and trenches) and TSVs. This invention provides a high-quality electroplating solution for these requirements. BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Figure 1 This is the effect of copper electroplating on a TSV hole array with a diameter of 5μm and a depth of 50μm.
[0043] Figure 2 This is the effect of copper electroplating on a blind hole with a diameter of 5μm and a depth of 50μm on a TSV wafer.
[0044] Figure 3 This is the effect of copper electroplating on a blind hole with a diameter of 2μm and a depth of 20μm on a TSV wafer.
[0045] Figure 4 This is the effect of copper electroplating on a blind hole with a diameter of 5μm and a depth of 50μm on a TSV wafer.
[0046] Figure 5 This is the effect of copper electroplating on a blind hole with a diameter of 10μm and a depth of 100μm on a TSV wafer.
[0047] Figure 6 This is the effect of copper electroplating on a blind hole with a diameter of 5μm and a depth of 50μm on a TSV wafer. DETAILED DESCRIPTION
[0048] The present invention is further described below through embodiments in conjunction with the accompanying drawings.
[0049] Example 1: Polymer 1 is synthesized by reacting polysuccinimide and N,N-dimethylethylenediamine, and its structural formula is:
[0050]
[0051] The synthesis steps are:
[0052] (1) At room temperature, add 10 mL of dimethyl sulfoxide and 1.94 g of polysuccinimide solid to a reaction flask and start the stirrer until the solid raw materials are completely dissolved;
[0053] (2) Continue to add 0.35 g of N,N-dimethylethylenediamine to the solution while keeping the stirrer on;
[0054] (3) After the addition is complete, the system is kept at room temperature for more than 48 hours;
[0055] (4) The reaction solution was added to acetone to precipitate the polymer; after filtration and washing, 2.19 g of polymer 1 (orange-yellow solid powder, yield 95.5%) was obtained.
[0056] Example 2: Polymer 2 was synthesized by reacting polysuccinimide, N,N-dimethylethylenediamine and iodomethane, and its structural formula is:
[0057]
[0058] The synthesis steps are:
[0059] (1) At room temperature, add 10 mL of dimethyl sulfoxide and 1.94 g of polysuccinimide solid to a reaction flask and start the stirrer until the solid raw materials are completely dissolved;
[0060] (2) Continue to add 0.35 g of N,N-dimethylethylenediamine to the solution while keeping the stirrer on;
[0061] (3) After the addition is complete, the system is kept at room temperature for more than 48 hours;
[0062] (4) Add 0.57 g of iodomethane to the solution and continue the reaction at room temperature for more than 24 hours;
[0063] (5) The reaction solution was added to acetone to precipitate the polymer; after filtration and washing, 2.61 g of polymer 2 (orange-yellow solid powder, yield 91.3%) was obtained.
[0064] Example 3: Polymer 3 is synthesized by reacting polysuccinimide with n-propylamine and N,N-dimethylethylenediamine, and its structural formula is:
[0065]
[0066] The synthesis steps are:
[0067] (1) At room temperature, 10 mL of N,N-dimethylformamide and 1.94 g of polysuccinimide solid were added to a reaction flask and stirred until the solid raw materials were completely dissolved to obtain a brown solution;
[0068] (2) Continue to add 0.35 g of N,N-dimethylethylenediamine and 0.95 g of n-propylamine to the solution while keeping the stirrer on;
[0069] (3) After the addition is complete, the system is kept at room temperature for more than 48 hours;
[0070] (4) The reaction solution was added to acetone to precipitate the polymer; after filtration and washing, 2.98 g of polymer 3 (orange-yellow solid powder, yield 92.1%) was obtained.
[0071] Example 4: Polymer 4 was synthesized by reacting polysuccinimide and N,N-dimethylethylenediamine, and its structural formula is:
[0072]
[0073] The synthesis steps are:
[0074] (1) At room temperature, 10 mL of N,N-dimethylacetamide and 1.94 g of polysuccinimide solid were added to a reaction flask and stirred until the solid raw materials were completely dissolved to obtain a brown solution;
[0075] (2) Continue to add 1.77 g of N,N-dimethylethylenediamine to the solution while keeping the stirrer on;
[0076] (3) After the addition is complete, the system is kept at room temperature for more than 48 hours;
[0077] (4) The reaction solution was added to acetone to precipitate the polymer; after filtration and washing, 3.56 g of polymer 4 (orange-yellow solid powder, yield 96.1%) was obtained.
[0078] Example 5: Polymer 5 was synthesized by reacting polysuccinimide and 1-(3-aminopropyl)imidazole, and its structural formula is:
[0079]
[0080] The synthesis steps are:
[0081] (1) At room temperature, 10 mL of dimethyl sulfoxide and 1.94 g of polysuccinimide solid were added to a reaction flask and stirred with a stirrer until the solid raw materials were completely dissolved to obtain a brown solution;
[0082] (2) Continue to add 2.50 g of 1-(3-aminopropyl)imidazole to the solution while keeping the stirrer on;
[0083] (3) After the addition is complete, the system is kept at room temperature for more than 48 hours;
[0084] (4) The reaction solution was added to acetone to precipitate the polymer; after filtration and washing, 4.29 g of polymer 5 (orange-yellow solid powder, yield 96.5%) was obtained.
[0085] Example 6, by reacting polysuccinimide and 1-(3-aminopropyl)imidazole, a polymer 6 is synthesized, and its structure is:
[0086]
[0087] The steps of synthesis are:
[0088] (1) At room temperature, 10 mL of N-methylpyrrolidone and 1.94 g of polysuccinimide solid were added to a reaction flask and stirred until the solid raw materials were completely dissolved to obtain a brown solution;
[0089] (2) Continue to add 0.50 g of 1-(3-aminopropyl)imidazole to the solution while keeping the stirrer on;
[0090] (3) After the addition is complete, the system is kept at room temperature for more than 48 hours;
[0091] (4) The reaction solution was added to acetone to precipitate the polymer; after filtration and washing, 2.28 g of polymer 6 (orange-yellow solid powder, yield 93.2%) was obtained.
[0092] Example 7, by reacting polysuccinimide and 1-(3-aminopropyl)imidazole, a polymer 7 was synthesized, and its structural formula is:
[0093]
[0094] The steps of synthesis are:
[0095] (1) At room temperature, 10 mL of dimethyl sulfoxide and 1.94 g of polysuccinimide solid were added to a reaction flask and stirred with a stirrer until the solid raw materials were completely dissolved to obtain a brown solution;
[0096] (2) Continue to add 0.35 g of N,N-dimethylethylenediamine and 0.24 g of n-propylamine to the solution while keeping the stirrer on;
[0097] (3) After the addition is complete, the system is kept at room temperature for more than 48 hours;
[0098] (4) The reaction solution was added to acetone to precipitate the polymer; after filtration and washing, 2.35 g of polymer 7 (orange-yellow solid powder, yield 92.7%) was obtained.
[0099] In Example 8, the polymer 1 synthesized in Example 1 was used as an additive in a copper electroplating solution to perform copper electroplating on a through silicon via (TSV) sample wafer with a copper seed layer, which had a large number of blind holes with a diameter of 5 μm and a depth of 50 μm.
[0100] Electroplating is performed using a copper electroplating solution composed of a base plating solution and an electroplating additive composition. During the electroplating process, the cathode is a sample piece with a through silicon via (TSV) and is connected to the negative pole of the power supply. The phosphor copper plate is connected to the positive pole of the power supply as the anode during electroplating. The electroplating process is to immerse the sample piece with the through silicon via (TSV) into the electroplating solution while applying a certain current. The equipment used for electroplating is a current source that can provide a constant current. The base plating solution contains 100g / L copper sulfate, 10g / L sulfuric acid, and 50ppm chloride ions. The electroplating additive contains 20ppm of polymer 1. Electroplating conditions: plating solution temperature 25°C, cathode current density and time 0.1ASD 3h; stirring is applied during the electroplating process.
[0101] TSV electroplating effect Figure 1 and Figure 2 There are basically no voids in the filled area, indicating that the electroplating solution formula can basically achieve defect-free filling of TSV blind hole structures with a diameter of 5μm and a depth of 50μm.
[0102] In Example 9, the polymer 2 synthesized in Example 2 was used as an additive in a copper electroplating solution to perform copper electroplating on a through silicon via (TSV) sample wafer with a copper seed layer, which had a large number of blind holes with a diameter of 2 μm and a depth of 20 μm.
[0103] Electroplating is performed using a copper electroplating solution composed of a base plating solution and an electroplating additive composition. During the electroplating process, the cathode is a sample piece with a through silicon via (TSV) and is connected to the negative pole of the power supply. The phosphor copper plate is connected to the positive pole of the power supply as the anode during electroplating. The electroplating process is to immerse the sample piece with the through silicon via (TSV) into the electroplating solution while applying a certain current. The equipment used for electroplating is a current source that can provide a constant current. The base plating solution contains 100g / L copper sulfate, 10g / L sulfuric acid, and 50ppm chloride ions. The electroplating additive contains 20ppm of polymer 2. Electroplating conditions: plating solution temperature 25°C, cathode current density and time 0.1ASD 3h; stirring is applied during the electroplating process.
[0104] Electroplating effect: The electroplating solution formula can basically achieve defect-free filling of blind hole structures of this size. TSV electroplating effect is as follows Figure 3 shown.
[0105] In Example 10, the polymer 3 synthesized in Example 3 was used as an additive in a copper electroplating solution to perform copper electroplating on a chip with a copper seed layer, which had a large number of trenches with a width of 45 nm.
[0106] Electroplating is performed using a copper electroplating solution comprising a base plating solution and an electroplating additive composition. During the electroplating process, the cathode is a chip with a copper seed layer, which is connected to the negative pole of a power supply. A phosphor copper plate serves as the anode during electroplating and is connected to the positive pole of the power supply. The electroplating process involves immersing the chip with the copper seed layer in the electroplating solution while applying a constant current. The electroplating equipment used is a current source capable of providing a constant current. The base plating solution contains 100 g / L copper sulfate, 10 g / L sulfuric acid, and 50 ppm chloride ions. The electroplating additive contains 20 ppm of polymer 3. Electroplating is performed by applying current in segments. Electroplating conditions include a plating solution temperature of 25°C, a cathode current density and time of 0.65 ASD for 6 s, 1 ASD for 40 s, and 6 ASD for 45 s; stirring is applied during the electroplating process.
[0107] Electroplating effect: The electroplating solution formula can basically achieve defect-free filling of the chip's trench structure.
[0108] In Example 11, the polymer 4 synthesized in Example 4 was used as an additive in a copper electroplating solution to perform copper electroplating on a through silicon via (TSV) sample wafer with a copper seed layer, which had a large number of blind holes with a diameter of 5 μm and a depth of 50 μm.
[0109] Electroplating is performed using a copper electroplating solution composed of a base plating solution and an electroplating additive composition. During the electroplating process, the cathode is a sample piece with a through silicon via (TSV) and is connected to the negative pole of the power supply. The phosphor copper plate is connected to the positive pole of the power supply as the anode during electroplating. The electroplating process is to immerse the sample piece with the through silicon via (TSV) into the electroplating solution while applying a certain current. The equipment used for electroplating is a current source that can provide a constant current. The base plating solution contains 100g / L copper sulfate, 10g / L sulfuric acid, and 50ppm chloride ions. The electroplating additive contains 20ppm of polymer 4. Electroplating conditions: plating solution temperature 25°C, cathode current density and time 0.1ASD 3h; stirring is applied during the electroplating process.
[0110] Electroplating effect: The electroplating solution formula can basically achieve defect-free filling of blind hole structures of this size. TSV electroplating effect is as follows Figure 4 shown.
[0111] In Example 12, the polymer 5 synthesized in Example 5 was used as an additive in a copper electroplating solution to perform copper electroplating on a through silicon via (TSV) sample wafer with a copper seed layer, which had a large number of blind holes with a diameter of 10 μm and a depth of 100 μm.
[0112] Electroplating is performed using a copper electroplating solution composed of a base plating solution and an electroplating additive composition. During the electroplating process, the cathode is a sample piece with a through silicon via (TSV) and is connected to the negative pole of the power supply. The phosphor copper plate is connected to the positive pole of the power supply as the anode during electroplating. The electroplating process is to immerse the sample piece with the through silicon via (TSV) into the electroplating solution while applying a certain current. The equipment used for electroplating is a current source that can provide a constant current. The base plating solution contains 100g / L copper sulfate, 10g / L sulfuric acid, and 50ppm chloride ions. The electroplating additive contains 20ppm of polymer 5. Electroplating conditions: plating solution temperature 25°C, cathode current density and time 0.1ASD 3h; stirring is applied during the electroplating process.
[0113] Electroplating effect: The electroplating solution formula can basically achieve defect-free filling of blind hole structures of this size. TSV electroplating effect is as follows Figure 5 shown.
[0114] In Example 13, the polymer 6 synthesized in Example 6 was used as an additive in a copper electroplating solution to perform copper electroplating on a through silicon via (TSV) sample wafer with a copper seed layer, which had a large number of blind holes with a diameter of 5 μm and a depth of 50 μm.
[0115] Electroplating is performed using a copper electroplating solution composed of a base plating solution and an electroplating additive composition. During the electroplating process, the cathode is a sample piece with a through silicon via (TSV) and is connected to the negative pole of the power supply. The phosphor copper plate is connected to the positive pole of the power supply as the anode during electroplating. The electroplating process is to immerse the sample piece with the through silicon via (TSV) into the electroplating solution while applying a certain current. The equipment used for electroplating is a current source that can provide a constant current. The base plating solution contains 100g / L copper sulfate, 10g / L sulfuric acid, and 50ppm chloride ions. The electroplating additive contains 20ppm of polymer 3. Electroplating conditions: plating solution temperature 25°C, cathode current density and time 0.1ASD 3h; stirring is applied during the electroplating process.
[0116] Electroplating effect: The electroplating solution formula can basically achieve defect-free filling of blind hole structures of this size. TSV electroplating effect is as follows Figure 6 shown.
[0117] In Example 14, the polymer 7 synthesized in Example 7 was used as an additive in a copper electroplating solution to perform copper electroplating on a through silicon via (TSV) sample wafer with a copper seed layer, which had a large number of blind holes with a diameter of 5 μm and a depth of 50 μm.
[0118] Electroplating is performed using a copper electroplating solution composed of a base plating solution and an electroplating additive composition. During the electroplating process, the cathode is a sample piece with a through silicon via (TSV) and is connected to the negative pole of the power supply. The phosphor copper plate is connected to the positive pole of the power supply as the anode during electroplating. The electroplating process is to immerse the sample piece with the through silicon via (TSV) into the electroplating solution while applying a certain current. The equipment used for electroplating is a current source that can provide a constant current. The base plating solution contains 100g / L copper sulfate, 10g / L sulfuric acid, and 50ppm chloride ions. The electroplating additive contains 20ppm of polymer 7. Electroplating conditions: plating solution temperature 25°C, cathode current density and time 0.1ASD 3h; stirring is applied during the electroplating process.
[0119] Electroplating effect: The electroplating solution formula can basically achieve defect-free filling of blind hole structures of this size.
[0120] In Example 15, the polymer 1 synthesized in Example 1 was used as an additive to the electroplating solution. In the electroplating example, silver electroplating was performed on a sample sheet to be plated with a silver seed layer, which had a large number of blind holes with a diameter of 5 μm and a depth of 50 μm.
[0121] Electroplating is performed using a copper electroplating solution comprising a base plating solution and an electroplating additive composition. During the electroplating process, the cathode is a sample piece to be plated with a silver seed layer, and is connected to the negative pole of a power supply. A pure silver plate is used as the anode during electroplating and is connected to the positive pole of the power supply. The electroplating process involves immersing the sample piece to be plated with a silver seed layer into the electroplating solution while applying a certain current. The equipment used for electroplating is a current source that can provide a constant current. The plating solution contains 30 g / L silver thiosulfate, 100 g / L sodium sulfite, 50 g / L potassium sodium tartrate, and 10 g / L sodium hydroxide. The electroplating additive contains 20 ppm of polymer 1. Electroplating conditions: plating solution temperature 25°C, cathode current density and time 0.1ASD 3h; stirring is applied during the electroplating process.
[0122] Electroplating effect: The electroplating solution formula can basically achieve defect-free filling of blind hole structures of this size.
[0123] In Example 16, the polymer 1 synthesized in Example 1 was used as an additive in the electroplating solution. During the electroplating process, cobalt electroplating was performed on a sample sheet to be plated with a cobalt seed layer, which had a large number of blind holes with a diameter of 5 μm and a depth of 50 μm.
[0124] Electroplating is carried out using a copper electroplating solution comprising a base plating solution and an electroplating additive composition. During the electroplating process, the cathode is a sample piece to be plated with a cobalt seed layer, and is connected to the negative pole of the power supply. A pure cobalt plate is connected to the positive pole of the power supply as the anode during electroplating. The electroplating process is to immerse the sample piece to be plated with a cobalt seed layer into the electroplating solution while applying a certain current. The equipment used for electroplating is a current source that can provide a constant current. The base plating solution contains 50g / L cobalt sulfate, 15g / L ammonium sulfate, and 30g / L boric acid. The electroplating additive contains 20ppm of polymer 1. Electroplating conditions: plating solution temperature 40°C, cathode current density and time 0.1ASD 3h; stirring is applied during the electroplating process.
[0125] Electroplating effect: The electroplating solution formula can basically achieve defect-free filling of blind hole structures of this size.
[0126] In summary, the additive provided by the present invention can be used in acid copper electroplating processes and can be applied to defect-free filling of blind via arrays and chip interconnects in TSV wafers, with good electroplating effects.
[0127] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description is not intended to limit the present invention. Any other changes, modifications, substitutions, combinations, and simplifications that do not depart from the spirit and principles of the present invention shall be considered equivalent replacements and shall be included within the scope of protection of the present invention.
Claims
1. An additive for metal electroplating, characterized in that: is an amide group-containing compound, the structure of which is shown in Formula 101; or is a protonated product of the amide group-containing compound or a quaternary ammonium salt thereof; Wherein, n1 is selected from a positive real number of 1 to 200; n2 is selected from 0 or a positive real number of 0 to 200; n3 is selected from 0 or a positive real number of 0 to 200; R1 is selected from a connecting group or a direct link of an alkyl group (C1-C5) or an aryl group; R2 is selected from a nitrogen-containing group or a nitrogen-containing molecular fragment; R3 is selected from an alkyl group (C1-C5), an aryl group, or a hydrogen atom.
2. The metal electroplating additive according to claim 1, characterized in that The R2 has a structure shown in Formula 102, Formula 103, Formula 104, or Formula 105: In formula 102, R 21 With R 22 are independently selected from hydrogen, alkyl (C1-C5) or aryl.
3. The metal electroplating additive according to claim 1 or 2, characterized in that: The protonated product is obtained by reacting the amide group-containing compound with an aqueous solution of hydrochloric acid, sulfuric acid, hydrobromic acid, perchloric acid, hydroiodic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, methanesulfonic acid or trifluoroacetic acid; or by reacting the amide group-containing compound with an acid in a metal electroplating solution; The quaternary ammonium salt product is obtained by reacting the amide group-containing compound with an alkylating agent, wherein the alkylating agent is selected from methyl iodide, ethyl iodide, methyl bromide, ethyl bromide, methyl chloride, ethyl chloride, benzyl chloride, dimethyl sulfate, diethyl sulfate, 1,3-propane sultone, 1,4-butane sultone, methyl p-toluenesulfonate, methyl benzenesulfonate, ethyl benzenesulfonate, ethylene oxide, propylene oxide, and epichlorohydrin.
4. The method for preparing the additive for metal electroplating according to any one of claims 1 to 3, characterized in that: Polysuccinimide and a compound containing a primary amine group are used as raw materials and reacted in the presence of a solvent to obtain a compound containing an amide group. The reaction route is: The solvent is selected from dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and water; the reaction is carried out under stirring; the reaction temperature is 0 to 120° C.; and the reaction time is 1 to 72 hours. After the reaction is completed, further processing includes at least one of precipitation, natural standing, rotary evaporation, beating, and recrystallization.
5. Use of the metal electroplating additive according to any one of claims 1 to 3 as a leveler and / or inhibitor in a metal electroplating bath.
6. The use according to claim 5, characterized in that The metal is copper, zinc, chromium, tin, nickel, cobalt, gold, silver, titanium, or an alloy of several of these metals; the metal electroplating solution includes metal salt, water, sulfuric acid, halogen salt, and the additive; the additive concentration is 1 to 1000 ppm.
7. The use according to claim 6, characterized in that Also includes accelerators and inhibitors.
8. The use according to claim 6 or 7, characterized in that When the metal is copper, the metal salt is selected from copper sulfate, copper methanesulfonate, and copper trifluoromethanesulfonate; and the halogen salt is selected from potassium bromide, sodium bromide, potassium iodide, sodium iodide, potassium chloride, and sodium chloride.
9. The use according to claim 8, characterized in that Electroplating copper plating solution is used for copper filling of through silicon vias, chips, glass substrates, circuit boards, packaging substrates, adapter plates, buried holes, through holes and trench structures, or for electroplating preparation of copper pillars and micro bumps.
10. The use according to claim 9, characterized in that: The accelerator is selected from the group consisting of thiourea, allylthiourea, acetylthiourea, MES (2-morpholineethanesulfonic acid), DPS (sodium N,N-dimethyldithiocarboxamide propane sulfonate), UPS (isothiourea propyl sulfate), ZPS (sodium 3-(benzothiazole-2-mercapto)-propane sulfonate), SPS (sodium polydisulfide propane sulfonate), MPS (sodium 3-mercapto-1-propane sulfonate), potassium salt of (O-ethyldithiocarbonate)-S-(3-sulfonate propyl) ester; The inhibitor is selected from the group consisting of polyethylene glycol, polypropylene glycol, block copolymers thereof, nitrogen-containing PEG / PPG copolymer Te701; amines; amides; and alkyl polyether sulfonates.