Metal electroplating composition and use method thereof
Through the combination of specific leveling agents and additives, the electroplating process is optimized, and the problems of holes and defects of metal plating compositions in high circuit density and small characteristic size semiconductor integrated circuits are solved, and the poreless, low impurities, dense structure and smooth surface are achieved, improving the uniformity and reliability of electroplating.
Patent Information
- Application Number
- CN202311838842.X
- 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, have high impurities of the coating, 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.
Metal electroplating compositions composed of structure-specific leveling agents and other additives, including copper salts, acid electrolytes, halide ion sources, accelerators and inhibitors, optimize the plating process to achieve a pore-free, low-impact, dense structure and smooth surface by controlling the current density and plating temperature.
The electroplating effect is achieved without holes, low plating impurities, good uniformity, dense structure and small surface roughness, which improves the uniformity and reliability of electroplating, and is suitable for semiconductor integrated circuits with high circuit density and small characteristic sizes.
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Figure CN120272997A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of metal electroplating, and more particularly 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 speeds and high circuit densities, have led to the reduction of 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 interconnect conductive. Copper has been introduced to replace aluminum for forming connection 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 metalize 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 increase in the 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. Today, 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 road to localization 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 strict. 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, additives for copper interconnect electroplating in chips provide better leveling of the deposits across the substrate surface, but tend to damage 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 electrolytic copper coatings.
[0008] Specifically, the present invention provides a metal electroplating composition comprising a leveling agent, and 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] x and y are each an arbitrary integer selected from 1 to 1100.
[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] Preferably, x and y are each an arbitrary integer selected from 3 to 750.
[0021] Preferably, the leveling agent is
[0022] Or
[0023] Preferably, the mass percentage concentration of the leveling agent is 0.1 to 30 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 sulfamate, and copper gluconate;
[0026] The mass concentration of copper sulfate in the copper salt is 11.5 - 155 g / L.
[0027] Preferably, the copper alkyl sulfonate is one or more of copper methanesulfonate, copper ethanesulfonate, and copper propanesulfonate; the copper aryl sulfonate 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, alkyl sulfonic acid, aryl sulfonic acid, and hydrochloric acid;
[0029] The mass concentration of the acidic electrolyte is 2 - 220 g / L.
[0030] Preferably, the alkyl sulfonic acid is one or more of methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, and trifluoromethanesulfonic acid; the aryl sulfonic 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 mass percentage concentration of the halide ion in the halide ion source is 2 - 85 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 (3-sulfopropyl) N,N-dimethyldithiocarbamate, potassium 3-mercapto-1-propanesulfonate, sodium 3-mercapto-1-propanesulfonate, sodium polydithiopropanesulfonate, carbonic acid bis(dithiocarbonato)-O-ethyl-S-ester and potassium 3-mercapto-1-propanesulfonate, disulfopropyl disulfide, sodium 3-(benzothiazolyl-S-thio)propylsulfonate, pyridinium propylsulfobetaine, sodium 1-sulfo-3-mercaptopropane-1-sulfonate, (3-sulfoethyl) N,N-dimethyldithiocarbamate, (3-sulfoethyl) 3-mercaptoethylpropylsulfonate, sodium 3-mercaptoethylsulfonate, carbonic acid bis(dithiocarbonato)-O-ethyl-S-ester and potassium 3-mercapto-1-ethanesulfonate, disulfethyl disulfide, sodium 3-(benzothiazolyl-S-thio)ethylsulfonate, pyridinium ethylsulfobetaine, and sodium 1-sulfo-3-mercaptoethane-1-sulfonate;
[0034] 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-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 mass percentage concentration of the accelerator is 1-90 ppm; the mass percentage concentration of the inhibitor is 2-380 ppm.
[0036] On the other hand, the present invention provides a method for using the metal electroplating composition as described above for electroplating printed circuit boards, wafer-level packages, and wafers or chips of integrated circuits, including:
[0037] 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; applying a current for electroplating.
[0038] Preferably, the density of the current is 0.1-50 ASD, and the temperature during the electroplating process is 10-40 °C.
[0039] Preferably, the density of the current is 0.3-40 ASD, and the temperature during the electroplating process is 25-35 °C.
[0040] After adopting the above technical solutions, compared with the prior art, the following beneficial effects are achieved:
[0041] 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;
[0042] 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. Specific Embodiments
[0043] The advantages of the present invention are further elaborated below in conjunction with specific embodiments.
[0044] 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 uniform mixing is 1 L (made up to 1 L with water), and water is the balance, which is not shown in the table.
[0045] Among them, Compound A1 is
[0046]
[0047] Compound A2 is:
[0048]
[0049] Compound B1 is:
[0050]
[0051] Table 1 Components and Their Contents of Examples 1-16 and Comparative Examples 1-7
[0052]
[0053]
[0054]
[0055] 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 wafer slices were observed by SEM for the filling rate, hole conditions, structural compactness, and surface roughness of the slices. The results are shown in Table 2.
[0056] Table 2 Electroplating Conditions and Test Results of Examples 1-16 and Comparative Examples 1-7
[0057] 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
[0058] Meanwhile, increasing the current density and electroplating temperature can improve the electroplating efficiency. 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.
[0059] 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.
[0060] 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.
[0061] It should be noted that the embodiments of the present invention have better implementability and are not any form of limitation to the present invention. Any person skilled in the art may use the disclosed technical content to change or modify it into equivalent effective embodiments. However, as long as it does not depart from the technical solution of the present invention, any modification, equivalent change, or modification made to the above embodiments according to 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 being a compound of formula (I): wherein, R1 is selected from an alkyl group or an aralkyl group; R2 is selected from an alkyl group or an aralkyl group; R3 is selected from an alkyl group or an aralkyl group; x and y are each an arbitrary integer selected from 1 to 1100.
2. The metal electroplating composition according to claim 1, wherein R1 is selected from the following groups:
3. The metal electroplating composition according to claim 1, characterized in that, R2 is selected from the following groups:
4. The metal electroplating composition according to claim 1, wherein R3 is selected from the following groups: CH3 5. The metal electroplating composition according to claim 1, characterized in that x and y are each 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 mass percentage concentration of the leveling agent is 0.1 to 30 ppm.
8. The metal electroplating composition according to claim 1, wherein Comprising 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 11.5 - 155 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 - 220 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 of the halide ion source is 2 - 85 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 polydithiopropane sulfonate, carbonic acid dithio-o-ethyl-s-ester and potassium 3-mercapto-1-propanesulfonate, disulfopropyl disulfide, sodium 3-(benzothiazolyl-s-thio)propyl 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, disulfoethyl disulfide, sodium 3-(benzothiazolyl-s-thio)ethyl 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 15, wherein the mass percentage concentration of the accelerator is 1-90 ppm; the mass percentage concentration of the inhibitor is 2-380 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, Comprising: bringing the metal electroplating composition into contact with a substrate to be electroplated, and the substrate may be a printed circuit board, a wafer-level package, and a wafer or chip of an integrated circuit; applying a current for electroplating.
18. The usage method according to claim 17, wherein the density of the current is 0.1-50 ASD, and the temperature during the electroplating process is 10-40 °C.
19. The usage method according to claim 18, wherein the density of the current is 0.3-40 ASD, and the temperature during the electroplating process is 25-35 °C.