Metal electroplating composition and use method
By optimizing the leveling agent and electroplating parameters, the problems of pores and defects in the metal electroplating composition during the electroplating process were solved, achieving an electroplating effect with no pores, low plating impurities, and good uniformity, which is suitable for semiconductor integrated circuits with high circuit density and small feature size.
Patent Information
- Application Number
- CN202311838876.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-28
- Publication Date
- 2026-01-16
AI Technical Summary
In the prior art, metal electroplating compositions are prone to producing pores and defects during the electroplating process, resulting in high impurities in the plating layer, poor plating uniformity, sparse structure, and large surface roughness, making it difficult to meet the requirements of high circuit density and small feature size semiconductor integrated circuits.
A metal electroplating composition consisting of a leveling agent with a specific structure and copper salt, acidic electrolyte, halide ion source, accelerator and inhibitor, including a leveling agent of formula (I), optimizes electroplating process parameters such as current density and temperature to ensure uniform deposition and dense structure.
It achieves electroplating effects with no pores, low plating impurities, good uniformity, smooth surface, and dense structure, and is suitable for semiconductor integrated circuits with high circuit density and small feature size, thus improving the reliability and uniformity of electroplating.
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Figure CN121344697A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of metal electroplating, in particular to a metal electroplating composition and a method of using the same. BACKGROUND
[0002] The demand for semiconductor integrated circuit (IC) devices, such as computer chips with high circuit speed and high circuit density, requires the reduction of feature size in ultra large scale integrated circuit (ULSI) and very large scale integrated circuit (VLSI) structures. The trend toward smaller device size and increased circuit density requires the reduction of the size of interconnect features and the increase of their density. Interconnect features are features formed in a dielectric substrate, such as a via or a trench, which are then filled with a metal, typically copper, to make the interconnect electrically conductive. Copper has been introduced to replace aluminum to form connections and interconnects in semiconductor substrates. Copper, which has better electrical conductivity than any metal except silver, is the metal of choice because copper metallization allows smaller features and less power to pass electricity. In a damascene process, electrolytic copper deposition is used to metallize the interconnect features of a semiconductor IC device.
[0003] As circuit density increases, the line width of interconnect lines, the size of contact vias, and other feature sizes will decrease, while the thickness of dielectric layers cannot be scaled down proportionally, resulting in an increase in feature aspect ratio. Secondly, in the back-end-of-line process of integrated circuits, copper has gradually replaced aluminum as the material used in the mainstream interconnection technology of ultra large scale integrated circuits. In current chip manufacturing, the wiring and interconnection of chips are almost entirely copper plating. Today, the technology node of logic chip technology has developed to the level of 28 nm and below, while the market for copper interconnection electroplating additives for this technology level is rare, and the road to localization of such products is extremely difficult.
[0004] However, as integrated circuit technology nodes continue to advance, the requirements for nanoscale void filling become more and more stringent. Researchers around the world are competing to develop electroplating methods, electroplating solutions and additives that can achieve no pores and defects, low impurities in the plated layer, good leveling, dense structure, and small surface roughness.
[0005] Generally speaking, copper interconnection electroplating additives for chips provide better leveling of the deposit across the substrate surface, but often compromise the leveling ability of the electroplating bath. Leveling ability is defined as the ratio of the thickness of the copper deposit at the center of the hole to the thickness at its surface.
[0006] Therefore, there is an urgent need for a metal electroplating composition that can ensure that the substrate surface after electroplating is free of pores and defects, has low impurities in the plated layer, good leveling, dense structure, and small surface roughness. SUMMARY
[0007] In order to overcome the technical problems existing in the prior art of metal electroplating composition, such as the generation of holes and defects, high impurities in the coating, poor uniformity, sparse structure, and surface roughness, the present invention provides a metal electroplating composition for electrolytic copper coating.
[0008] Specifically, the present invention provides a metal electroplating composition comprising a leveling agent, wherein the leveling agent is a compound of formula (I):
[0009]
[0010] R1 is selected from alkyl or aralkyl groups;
[0011] R2 is selected from alkyl or aralkyl groups;
[0012] R3 is selected from alkyl or aralkyl groups;
[0013] x and y are integers selected from 1 to 1500.
[0014] Preferably, R1 is selected from the following groups:
[0015]
[0016] Preferably, R2 is selected from the following groups:
[0017]
[0018] Preferably, R3 is selected from the following groups:
[0019]
[0020] 5. The metal electroplating composition according to claim 1, characterized in that,
[0021] x and y are any integers selected from 3 to 750.
[0022] Preferably, the leveling agent is
[0023] or
[0024] Preferably, the mass percentage concentration of the leveling agent is 0.1 to 30 ppm.
[0025] Preferred components include copper salts, acidic electrolytes, halide ion sources, accelerators, inhibitors, and water.
[0026] Preferably, the copper salt is selected from one or more of copper sulfate, copper halide, copper acetate, copper nitrate, copper fluoroborate, alkyl sulfonate, aryl sulfonate, copper aminosulfonate, and copper gluconate;
[0027] The mass concentration of the copper salt is 12.5-180 g / L.
[0028] Preferably, the alkyl sulfonate copper is one or more selected from copper methane sulfonate, copper ethane sulfonate, and copper propane sulfonate;
[0029] The aryl sulfonate copper is one or more of phenyl sulfonate copper, phenol sulfonate copper, and p-toluene sulfonate copper.
[0030] Preferably, the acidic electrolyte is one or more selected from sulfuric acid, phosphoric acid, acetic acid, fluoroboric acid, aminosulfonic acid, alkylsulfonic acid, arylsulfonic acid, and hydrochloric acid;
[0031] The mass concentration of the acidic electrolyte is 2-210 g / L.
[0032] Preferably, the alkyl sulfonic acid is one or more of methane sulfonic acid, ethane sulfonic acid, propane sulfonic acid, and trifluoromethane sulfonic acid; and the aryl sulfonic acid is one or more of phenyl sulfonic acid, phenol sulfonic acid, and toluene sulfonic acid.
[0033] Preferably, the halide ion source is a chloride ion source;
[0034] The mass percentage concentration of halide ions in the halide ion source is 2-75 ppm.
[0035] Preferably, the chloride ion source is one or more of copper chloride, tin chloride, and hydrochloric acid.
[0036] Preferably, the accelerator is selected from N,N-dimethyl-dithiocarbamate-(3-sulfopropyl) ester, potassium salt of 3-mercapto-1-propanesulfonate, sodium salt of 3-mercapto-propylsulfonate, sodium polydithiodipropanesulfonate, dithio-o-ethyl ester-s-ester and potassium salt of 3-mercapto-1-propanesulfonate, disulfopropyl disulfide, sodium salt of 3-(benzothiazolyl-s-thio)propylsulfonate, pyridinium propyl sulfobetaine, 1-sodium-3-mercaptopropane-1- One or more of the following: sulfonates, N,N-dimethyl-dithiocarbamate-(3-sulfoethyl) ester, 3-mercapto-ethylpropylsulfonate-(3-sulfoethyl) ester, sodium salt of 3-mercaptoethylsulfonate, dithio-o-ethyl ester-s-ester and potassium salt of 3-mercapto-1-ethanesulfonate, disulfoethyl disulfide, sodium salt of 3-(benzothiazolyl-s-thio)ethylsulfonate, pyridinium ethyl sulfobetaine and 1-sodium-3-mercaptoethane-1-sulfonate;
[0037] The inhibitor is selected from one or more of the following: polypropylene glycol copolymer, polyethylene glycol copolymer, ethylene oxide-propylene oxide copolymer, octadecyl alcohol polyethylene glycol ether, nonylphenol polyethylene glycol ether, octyl alcohol polyalkylene glycol ether, octane glycol-bis-(polyalkylene glycol ether), poly(ethylene glycol-ran-propylene glycol), poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol), poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol), and butanol ethylene oxide-propylene oxide copolymer.
[0038] Preferably, the accelerator has a mass percentage concentration of 1 to 85 ppm;
[0039] The mass percentage concentration of the inhibitor is 2–380 ppm.
[0040] Another aspect of the present invention discloses a method of using the metal electroplating composition described above for electroplating printed circuit boards, wafer-level packaging, and integrated circuit wafers or chips, comprising:
[0041] The metal electroplating composition is brought into contact with the substrate to be electroplated, wherein the substrate may be a printed circuit board, a wafer-level package, or an integrated circuit wafer or chip;
[0042] Electroplating is performed by applying an electric current.
[0043] Preferably, the current density is 0.1-50 ASD and the electroplating temperature is 10-40℃.
[0044] Preferably, the current density is 0.3-40 ASD, and the electroplating process temperature is 25-35°C.
[0045] Compared with existing technologies, the above technical solution has the following advantages:
[0046] 1. It can achieve technical effects such as no holes or defects, low coating impurities, good uniformity, dense structure, and small surface roughness;
[0047] 2. The metal electroplating composition described herein possesses excellent thermal reliability and uniform plating capability, and can solve the problem of sealing orifices. "Orifice" refers to a recessed feature including through holes and blind channels. It has significant industrial application value. Detailed Implementation
[0048] The advantages of the present invention will be further illustrated below with reference to specific embodiments.
[0049] The metal plating compositions of Examples 1-16 and Comparative Examples 1-7 were prepared according to the components and contents described in Table 1. All components were mixed uniformly, and the volume of the uniformly mixed plating composition was 1L (diluted to 1L with water), with water as the balance, not shown in the table.
[0050] Among them, compound A1 is
[0051]
[0052] Compound A2 is:
[0053]
[0054] Compound B1 is:
[0055]
[0056] Table 1. Components and their contents in Examples 1-16 and Comparative Examples 1-7
[0057]
[0058]
[0059]
[0060] To further test the properties of the above-mentioned metal electroplating composition, patterned wafer material with a PVD seed layer was electroplated under the corresponding electroplating conditions. The fill rate, porosity, structural compactness and surface roughness of the electroplated wafer slices were observed by SEM. The results are shown in Table 2.
[0061] Table 2 Electroplating conditions and test results for Examples 1-16 and Comparative Examples 1-7
[0062] Metal plating composition Current density Plating temperature Plating surface roughness Filled with voids Structural density Example 1 0.3 ASD 25℃ Smooth None Dense Example 2 0.3 ASD 25℃ Smooth None Dense Example 3 0.3 ASD 25℃ Smooth None Dense Example 4 20 ASD 25℃ Smooth None Dense Example 5 20 ASD 25℃ Smooth None Dense Example 6 40 ASD 25℃ Smooth None Dense Example 7 40 ASD 25℃ Smooth None Dense Example 8 0.3 ASD 25℃ Smooth None Dense Example 9 0.3 ASD 25℃ Smooth None Dense Example 10 0.3 ASD 25℃ Smooth None Dense Example 11 20 ASD 25℃ Smooth None Dense Example 12 20 ASD 25℃ Smooth None Dense Example 13 40 ASD 25℃ Smooth None Dense Example 14 40 ASD 25℃ Smooth None Dense Example 15 40 ASD 35℃ Smooth None Dense Example 16 40 ASD 35℃ Smooth None Dense Comparative Example 1 0.3 ASD 25℃ Rough Yes Loose Comparative Example 2 0.3 ASD 25℃ Rough Yes Loose Comparative Example 3 0.3 ASD 25℃ Rough Yes Loose Comparative Example 4 20 ASD 25℃ Rough Yes Loose Comparative Example 5 20 ASD 25℃ Rough Yes Loose Comparative Example 6 0.3 ASD 35℃ Rough Yes Loose Comparative Example 7 0.3 ASD 35℃ Rough Yes Loose
[0063] Meanwhile, increasing the current density and electroplating temperature can improve electroplating efficiency. If the temperature is too high, the electroplating solution is prone to evaporation and the additive concentration will change. If the temperature is too low, the electroplating efficiency will be reduced.
[0064] Therefore, the metal electroplating composition of the present invention can provide a superior electroplating effect by selecting a leveling agent with a specific structure: the surface of the electroplated material is smooth, the filler is pore-free and the structure is dense; and the operable window is large, which can meet the actual production needs and has good application prospects.
[0065] In this invention, A = ampere; A / dm 2= Amperes per square decimeter = ASD; °C = degrees Celsius; ppm = parts per million. Unless otherwise specified, all quantities are percentages by mass.
[0066] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.
Claims
1. A metal electroplating composition characterized in that, The leveling agent is a compound of formula (I): wherein R1 is selected from alkyl or aralkyl; R2 is selected from alkyl or aralkyl; R3 is selected from alkyl or aralkyl; x and y are each an arbitrary integer selected from 1 to 1500.
2. The metal electroplating composition of claim 1, wherein, R1 is selected from the group consisting of:
3. The metal electroplating composition of claim 1, wherein R2 is selected from the group consisting of:
4. The metal electroplating composition of claim 1, wherein R3 is selected from the group consisting of: -CH3, 5. The metal electroplating composition of claim 1, wherein, x and y are each an arbitrary integer selected from 3 to 750.
6. The metal electroplating composition of claim 1, wherein, the leveling agent is or 7. The metal electroplating composition of claim 1, wherein, the mass percent concentration of the leveling agent is 0.1 to 30 ppm.
8. The metal electroplating composition of claim 1, wherein, The copper salt, the acidic electrolyte, the halide source, the accelerator, the suppressor, and the water.
9. The metal electroplating composition of claim 8, wherein, the copper salt is selected from one or more of copper sulfate, copper halide, copper acetate, copper nitrate, copper fluoroborate, copper alkylsulfonate, copper arylsulfonate, copper aminosulfonate, and copper gluconate; the mass concentration of the copper salt is 12.5 to 180 g / L.
10. The metal electroplating composition of claim 9, wherein, the copper alkylsulfonate is one or more of copper methane sulfonate, copper ethane sulfonate, and copper propane sulfonate; the copper arylsulfonate is one or more of copper phenyl sulfonate, copper phenol sulfonate, and copper p-toluene sulfonate.
11. The metal electroplating composition of claim 8, wherein, the acidic electrolyte is one or more of sulfuric acid, phosphoric acid, acetic acid, fluoroboric acid, aminosulfonic acid, alkylsulfonic acid, arylsulfonic acid, and hydrochloric acid; the mass concentration of the acidic electrolyte is 2 to 210 g / L.
12. The metal electroplating composition of claim 11, wherein, the alkylsulfonic acid is one or more of methane sulfonic acid, ethane sulfonic acid, propane sulfonic acid, and trifluoromethane sulfonic acid; the arylsulfonic acid is one or more of phenyl sulfonic acid, phenol sulfonic acid, and toluene sulfonic acid.
13. The metal electroplating composition of claim 8, wherein, the halide source is a chloride source; the mass percent concentration of the halide of the halide source is 2 to 75 ppm.
14. The metal electroplating composition of claim 13, wherein, the chloride source is one or more of copper chloride, tin chloride, and hydrochloric acid.
15. The metal electroplating composition of claim 8, wherein, the accelerator is selected from one or more of N,N-dimethyl-dithio carbamic acid-(3-sulfopropyl) ester, 3-mercapto-1-propane sulfonic acid potassium salt, 3-mercapto-propyl sulfonic acid sodium salt, polydisulfide dipropanesulfonic acid sodium salt, carbonic acid dithio-o-ethyl ester-s-ester with 3-mercapto-1-propane sulfonic acid potassium salt, bis-sulfopropyl disulfide, 3-(benzothiazolyl-s-sulfenyl) propyl sulfonic acid sodium salt, pyridinium propyl sulfobetaine, 1-sodium-3-mercapto propane-1-sulfonate, N,N-dimethyl-dithio carbamic acid-(3-sulfoethyl) ester, 3-mercapto-ethyl propyl sulfonic acid-(3-sulfoethyl) ester, 3-mercapto ethyl sulfonic acid sodium salt, carbonic acid dithio-o-ethyl ester-s-ester with 3-mercapto-1-ethane sulfonic acid potassium salt, bis-sulfoethyl disulfide, 3-(benzothiazolyl-s-sulfenyl) ethyl sulfonic acid sodium salt, pyridinium ethyl sulfobetaine, and 1-sodium-3-mercapto ethane-1-sulfonate; the inhibitor is selected from one or more of polypropylene glycol copolymer, polyethylene glycol copolymer, oxirane-propylene oxide copolymer, octadecanol polyethylene glycol ether, nonyl phenol polyethylene glycol ether, octanol polyalkylene glycol ether, octane diol-bis-(polyalkylene glycol ether), poly(ethylene glycol-ran-propylene glycol), poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol), poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol), and butanol oxirane-propylene oxide copolymer.
16. The metal electroplating composition of claim 15, wherein: the mass percent concentration of the accelerator is 1-85 ppm; the mass percent concentration of the inhibitor is 2-380 ppm.
17. A method of using the metal electroplating composition of any one of claims 1-16 for electroplating printed circuit boards, wafer-level packages, and wafers or dies of integrated circuits, characterized in that, comprising: contacting the metal electroplating composition with a substrate to be electroplated, the substrate can be a printed circuit board, a wafer or chip of a wafer level package and an integrated circuit; applying an electric current to electroplate.
18. The method of use of claim 17, wherein: the density of the electric current is 0.1-50 ASD and the temperature of the electroplating process is 10-40 °C.
19. The method of use of claim 18, wherein: the density of the electric current is 0.3-40 ASD and the temperature of the electroplating process is 25-35 °C.