Metal electroplating composition and use method thereof
Through the specific composition of metal plating composition and controlling the plating parameters, the holes and defects in the plating process are solved, and the pores and defects are achieved without holes, low impurities, dense structures and smooth surfaces are achieved, meeting the needs of semiconductor integrated circuits with high circuit density and small characteristic sizes.
Patent Information
- Application Number
- CN202311838900.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-28
- Publication Date
- 2025-07-08
AI Technical Summary
In the prior art, metal electroplating compositions are prone to holes and defects during the electroplating process, and the coating is highly impurities, poor uniform plating, sparse structure, and large surface roughness, making it difficult to meet the needs of semiconductor integrated circuits with high circuit density and small characteristic sizes.
A metal electroplating composition consisting of a specific structure leveling agent and a copper salt, acid electrolyte, halide ion source, accelerator, inhibitor, etc. is used to achieve a poreless, low impurity, dense structure and smooth surface by controlling the current density and plating temperature.
It has achieved electroplating effect with no holes, low impurities, good uniform plating, dense structure and small surface roughness. It is suitable for semiconductor integrated circuits with high circuit density and small characteristic sizes, and has good thermal reliability and industrial application value.
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Figure CN120272998A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of metal electroplating, and particularly relates to a metal electroplating composition and a method for using the same. Background Art
[0002] The requirements for semiconductor integrated circuit (IC) devices, such as computer chips with high circuit speed and high circuit density, necessitate reducing the feature sizes in very large scale integration (ULSI) and very large scale integration (VLSI) structures. The trend towards smaller device sizes and increased circuit density requires reducing the size of interconnect features and increasing their density. Interconnect features are features formed in a dielectric substrate, such as vias or trenches, which are then filled with a metal (typically copper) to make the interconnection conductive. Copper has been introduced to replace aluminum for forming connecting lines and interconnections in semiconductor substrates. Copper, which has better electrical conductivity than any metal other than silver, is the metal of choice because copper metallization allows for smaller features and uses less energy to conduct electricity. In damascene processing, electrolytic copper deposition is used to metallize the interconnect features of semiconductor IC devices.
[0003] As the circuit density increases, the line width of the interconnect lines, the size of the contact vias, and other feature sizes will all decrease accordingly, while the thickness of the dielectric layer cannot be reduced proportionally, resulting in an increased aspect ratio of the features. Secondly, in the back-end processes of integrated circuits, copper has gradually replaced aluminum as the material used in the mainstream interconnect technology for very large scale integrated circuits. In current chip manufacturing, almost all of the chip wiring and interconnections use copper plating. Now the logic chip technology node has developed to a technical level of 28 nm and below, but there are very few products on the market for copper interconnect electroplating additives for this technical level, and the path to domestic production of such products is extremely difficult.
[0004] However, as the integrated circuit technology node continues to advance, the requirements for filling nano-scale voids are becoming increasingly stringent. Researchers in various countries are competing to study electroplating methods, electroplating solutions, and additives that can achieve hole-free and defect-free, low plating impurities, good throwing power, dense structure, and small surface roughness.
[0005] Generally speaking, additives for chip copper interconnect electroplating provide better leveling of the deposits across the substrate surface, but often impair the throwing power of the electroplating bath. The throwing power is defined as the ratio of the copper deposit thickness at the center of the hole to its thickness at the surface.
[0006] Therefore, there is an urgent need for a metal electroplating composition that can ensure a hole-free and defect-free substrate surface after electroplating, low plating impurities, good throwing power, dense structure, and small surface roughness. Summary of the Invention
[0007] In order to overcome the technical problems existing in electroplating with metal electroplating compositions in the prior art, such as the generation of holes and defects, high impurity content in the coating, poor throwing power, sparse structure, and surface roughness, the present invention provides a metal electroplating composition for an electrolytic copper coating.
[0008] Specifically, the present invention provides a metal electroplating composition comprising a leveling agent; the leveling agent is a compound of formula (I):
[0009]
[0010] wherein, R1 is selected from alkyl or aralkyl;
[0011] R2 is selected from alkyl or aralkyl;
[0012] R3 is selected from alkyl or aralkyl;
[0013] n is an arbitrary integer selected from 1 to 1500.
[0014] Preferably, the 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] Preferably, n is an arbitrary integer selected from 3 to 750.
[0021] Preferably, the leveling agent is
[0022] or
[0023] Preferably, the concentration of the leveling agent is 0.1 - 35 ppm.
[0024] Preferably, it further comprises a copper salt, an acidic electrolyte, a halide ion source, an accelerator, an inhibitor, and water.
[0025] Preferably, 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;
[0026] The mass concentration of copper sulfate in the copper salt is 12.5 - 180 g / L.
[0027] Preferably, the copper alkylsulfonate is one or more of copper methanesulfonate, copper ethanesulfonate, and copper propanesulfonate; the copper arylsulfonate is one or more of copper benzenesulfonate, copper phenolsulfonate, and copper p-toluenesulfonate.
[0028] Preferably, the acidic electrolyte is one or more of sulfuric acid, phosphoric acid, acetic acid, fluoboric acid, sulfamic acid, alkylsulfonic acid, arylsulfonic acid, and hydrochloric acid;
[0029] The mass concentration of the acidic electrolyte is 2 - 210 g / L.
[0030] Preferably, the alkylsulfonic acid is one or more of methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, and trifluoromethanesulfonic acid; the arylsulfonic acid is one or more of benzenesulfonic acid, phenolsulfonic acid, and toluenesulfonic acid.
[0031] Preferably, the halide ion source is a chloride ion source; the concentration of the halide ions in the halide ion source is 2 - 80 ppm.
[0032] Preferably, the chloride ion source is one or more of copper chloride, tin chloride, and hydrochloric acid.
[0033] Preferably, the accelerator is selected from one or more of N,N-dimethyl-dithiocarbamate-(3-sulfopropyl) ester, potassium 3-mercapto-1-propanesulfonate, sodium 3-mercapto-1-propanesulfonate, sodium polydithiopropanesulfonate, carbonic acid dithiocarbonate-o-ethyl-s-ester and potassium 3-mercapto-1-propanesulfonate, disulfopropyl disulfide, sodium 3-(benzothiazolyl-s-thio) propanesulfonate, pyridinium propyl sulfobetaine, 1-sodium-3-mercaptopropane-1-sulfonate, N,N-dimethyl-dithiocarbamate-(3-sulfoethyl) ester, 3-mercapto-ethylpropylsulfonic acid-(3-sulfoethyl) ester, sodium 3-mercaptoethylsulfonate, carbonic acid - dithiocarbonate-o-ethyl-s-ester and potassium 3-mercapto-1-ethanesulfonate, disulfonethyl disulfide, sodium 3-(benzothiazolyl-s-thio) ethylsulfonate, pyridinium ethyl sulfobetaine, and 1-sodium-3-mercaptoethane-1-sulfonate;
[0034] The inhibitor is selected from one or more of polypropylene glycol copolymers, polyethylene glycol copolymers, ethylene oxide - propylene oxide copolymers, octadecyl alcohol polyethylene glycol ether, nonylphenol polyethylene glycol ether, octanol polyalkylene glycol ether, octanediol - bis-(polyalkylene glycol ether), poly(ethylene glycol - ran - propylene glycol), poly(ethylene glycol)-block-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.
[0035] Preferably, the concentration of the accelerator is 1 to 90 ppm;
[0036] The concentration of the inhibitor is 2 to 380 ppm.
[0037] On the other hand, the present invention discloses a method for using the metal electroplating composition as described above for electroplating a printed circuit board, a wafer-level package, and a wafer or chip of an integrated circuit, including:
[0038] Bringing the metal electroplating composition into contact with a substrate to be electroplated, where the substrate can be a printed circuit board, a wafer-level package, and a wafer or chip of an integrated circuit;
[0039] Applying a current for electroplating within a first electroplating temperature range.
[0040] Preferably, the density of the current is 0.1 - 50 ASD, and the first electroplating temperature range is 10 - 40 °C.
[0041] Preferably, the density of the current is 0.3 - 40 ASD, and the first electroplating temperature range is 25 - 35 °C.
[0042] After adopting the above technical solutions, compared with the prior art, the following beneficial effects are achieved:
[0043] 1. Technical effects such as no holes and defects, low impurity content in the coating, good throwing power, dense structure, and small surface roughness can be achieved;
[0044] 2. The metal electroplating composition can have good thermal reliability and throwing power, and can solve the problem of orifice sealing. "Orifice" refers to recessed features including through-holes and blind channels. It has good industrial application value. Detailed Embodiments
[0045] The advantages of the present invention are further elaborated below in conjunction with specific embodiments.
[0046] Prepare the metal electroplating compositions of Examples 1 - 16 and Comparative Examples 1 - 7 according to the components and contents described in Table 1. Just mix each component evenly. The volume of the electroplating composition after even mixing is 1 L (made up to 1 L with water), and water is the balance, which is not shown in the table.
[0047] Among them, Compound A1 is
[0048]
[0049] Compound A2 is:
[0050]
[0051] Compound B1 is:
[0052]
[0053] Table 1 Components and Their Contents of Examples 1-16 and Comparative Examples 1-7
[0054]
[0055]
[0056]
[0057] In order to further test the properties of the above metal electroplating composition, electroplating was carried out on a patterned wafer material with a PVD seed layer as the electroplating substrate under corresponding electroplating conditions. After electroplating, the electroplated wafer was sliced and observed by SEM for the filling rate, hole condition, structural density, and surface roughness of the slice. The results are shown in Table 2.
[0058] Table 2 Electroplating Conditions and Test Results of Examples 1-16 and Comparative Examples 1-7
[0059] Metal electroplating composition Current density Electroplating temperature Electroplated surface roughness Whether there are holes Structural compactness Example 1 0.3 ASD 25℃ Smooth No Dense Example 2 0.3 ASD 25℃ Smooth No Dense Example 3 0.3 ASD 25℃ Smooth No Dense Example 4 20 ASD 25℃ Smooth No Dense Example 5 20 ASD 25℃ Smooth No Dense Example 6 40 ASD 25℃ Smooth No Dense Example 7 40 ASD 25℃ Smooth No Dense Example 8 0.3 ASD 25℃ Smooth No Dense Example 9 0.3 ASD 25℃ Smooth No Dense Example 10 0.3 ASD 25℃ Smooth No Dense Example 11 20 ASD 25℃ Smooth No Dense Example 12 20 ASD 25℃ Smooth No Dense Example 13 40 ASD 25℃ Smooth No Dense Example 14 40 ASD 25℃ Smooth No Dense Example 15 40 ASD 35℃ Smooth No Dense Example 16 40 ASD 35℃ Smooth No 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
[0060] Based on the test data shown in Table 2, it can be seen that during electroplating, increasing the current density and electroplating temperature can improve the electroplating efficiency. However, if the temperature is too high, the electroplating solution is prone to evaporation and the additive concentration changes. If the temperature is too low, the electroplating efficiency will be reduced. The leveling agent selected in the present invention can effectively improve the surface morphology characteristics of the material after electroplating with the metal electroplating composition.
[0061] Therefore, the metal electroplating composition in the present invention can provide relatively excellent electroplating effects by selecting a leveling agent with a specific structure: the surface of the electroplated material is smooth, the filler has no holes, and the structure is dense; and the operable window is relatively large, which can meet the actual production requirements and has good application prospects.
[0062] In the present invention, A = ampere; A / dm 2 = ampere per square decimeter = ASD; °C = degree Celsius; ppm = parts per million. Unless otherwise specified, all amounts are in mass percentages.
[0063] It should be noted that the embodiments of the present invention have better implementability and do not impose any form of limitation on the present invention. Any person skilled in the art may use the technical content disclosed above to modify or transform it into equivalent effective embodiments. However, as long as it does not depart from the technical content of the present invention, any modification, equivalent change, or modification made to the above embodiments based on the technical essence of the present invention still falls within the scope of the technical solution of the present invention.
Claims
1. A metal electroplating composition, characterized in that, Comprising a leveling agent; 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; n is an arbitrary integer selected from 1 to 1500.
2. The metal electroplating composition according to claim 1, wherein Said R1 is selected from the following groups:
3. The metal electroplating composition according to claim 1, characterized in that, Said R2 is selected from the following groups:
4. The metal electroplating composition according to claim 1, wherein Said R3 is selected from the following groups: -CH3, 5. The metal electroplating composition according to claim 1, characterized in that n is an arbitrary integer selected from 3 to 750.
6. The metal electroplating composition according to claim 1, characterized in that The leveling agent is or 7. The metal electroplating composition according to claim 1, characterized in that The concentration of the leveling agent is 0.1 to 35 ppm.
8. The metal electroplating composition according to claim 1, characterized in that It further comprises a copper salt, an acidic electrolyte, a halide ion source, an accelerator, an inhibitor and water.
9. The metal electroplating composition according to claim 8, characterized in that 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 copper sulfate in the copper salt is 12.5 - 180 g / L.
10. The metal electroplating composition according to claim 9, characterized in that The copper alkylsulfonate is one or more of copper methanesulfonate, copper ethanesulfonate and copper propanesulfonate; the copper arylsulfonate is one or more of copper benzenesulfonate, copper phenolsulfonate and copper p-toluenesulfonate.
11. The metal electroplating composition according to claim 8, characterized in that 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 - 210 g / L.
12. The metal electroplating composition according to claim 11, characterized in that The alkylsulfonic acid is one or more of methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid and trifluoromethanesulfonic acid; the arylsulfonic acid is one or more of benzenesulfonic acid, phenolsulfonic acid and toluenesulfonic acid.
13. The metal electroplating composition according to claim 8, characterized in that The halide ion source is a chloride ion source; the concentration of the halide ions in the halide ion source is 2 - 80 ppm.
14. The metal electroplating composition according to claim 13, characterized in that The chloride ion source is one or more of copper chloride, tin chloride and hydrochloric acid.
15. The metal electroplating composition according to claim 8, characterized in that The accelerator is selected from one or more of N,N-dimethyl-dithiocarbamic acid-(3-sulfopropyl) ester, potassium 3-mercapto-1-propanesulfonate, sodium 3-mercapto-propane sulfonate, sodium bis(3-sulfopropyl)disulfide, carbonic acid dithio-o-ethyl-s-ester and potassium 3-mercapto-1-propanesulfonate, disulfobis(propylsulfonic acid), sodium 3-(benzothiazolyl-s-thio)propane sulfonate, pyridinium propyl sulfobetaine, 1-sodium-3-mercaptopropane-1-sulfonate, N,N-dimethyl-dithiocarbamic acid-(3-sulfoethyl) ester, 3-mercapto-ethylpropyl sulfonic acid-(3-sulfoethyl) ester, sodium 3-mercaptoethyl sulfonate, carbonic acid-dithio-o-ethyl-s-ester and potassium 3-mercapto-1-ethanesulfonate, disulfobis(ethylsulfonic acid), sodium 3-(benzothiazolyl-s-thio)ethane sulfonate, pyridinium ethyl sulfobetaine, and 1-sodium-3-mercaptoethane-1-sulfonate; The inhibitor is selected from one or more of polypropylene glycol copolymer, polyethylene glycol copolymer, ethylene oxide-propylene oxide copolymer, octadecanol polyethylene glycol ether, nonylphenol polyethylene glycol ether, octanol polyalkylene glycol ether, octanediol-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.
16. The metal electroplating composition according to claim 1, wherein the concentration of the accelerator is 1 to 90 ppm; the concentration of the inhibitor is 2 to 380 ppm.
17. A method of using a metal electroplating composition as described in any one of claims 1-16 for electroplating a printed circuit board, a wafer-level package, and a wafer or chip of an integrated circuit, characterized in that, including: bringing the metal electroplating composition into contact with a substrate to be electroplated, and the substrate can be a printed circuit board, a wafer-level package, and a wafer or chip of an integrated circuit; applying a current for electroplating within a first electroplating temperature range.
18. The use method according to claim 17, wherein the density of the current is 0.1-50 ASD, and the first electroplating temperature range is 10-40 °C.
19. The use method according to claim 18, wherein the density of the current is 0.3-40 ASD, and the first electroplating temperature range is 25-35 °C.