Metal electroplating composition
By optimizing the types and proportions of additives in the metal electroplating composition, the problems of uneven copper filling and void formation in semiconductor manufacturing have been solved, achieving a copper filling effect with no voids, low impurity content, and a smooth surface, which is suitable for metallization of printed circuit boards and semiconductor substrates.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- ANJI MICROELECTRONICS TECH (SHANGHAI) CO LTD
- Filing Date
- 2025-11-28
- Publication Date
- 2026-06-18
AI Technical Summary
In semiconductor manufacturing, uneven deposition and void formation are problems during electroplating, especially in narrow structures where it is difficult to achieve void-free and defect-free copper filling, which affects the reliability and scalability of semiconductor devices.
A metal electroplating composition comprising copper sulfate, sulfuric acid, chloride ions, accelerator, inhibitor, and leveling agent is used, and the types and proportions of additives are optimized to achieve uniform copper deposition.
It achieves a void-free, low-impurity, and smooth copper-filling effect in semiconductor manufacturing, suitable for metallization of printed circuit boards, IC carriers, and semiconductor substrates, especially in TSV filling, double damask plating, redistribution lines, and glass vias, ensuring defect-free copper layer deposition.
Smart Images
Figure PCTCN2025138360-FTAPPB-I100001 
Figure PCTCN2025138360-FTAPPB-I100002 
Figure PCTCN2025138360-FTAPPB-I100003
Abstract
Description
A metal electroplating composition Technical Field
[0001] This invention relates to the field of semiconductor electroplating, and more particularly to a metal electroplating composition. Background Technology
[0002] During electroplating, voltage drops typically vary along irregular surfaces, potentially leading to uneven metal deposition. This irregularity is exacerbated when voltage drops are relatively extreme, i.e., when surface irregularities are significant. Using unsuitable plating solutions in semiconductor manufacturing can also create numerous voids in vias or trenches, which can cause open circuits in the semiconductor. As the geometry of electronic devices shrinks, plating a uniform copper layer while completely filling smaller features becomes increasingly difficult. The introduction of electrochemical copper deposition (ECD) was a significant milestone in the semiconductor industry, improving the reliability and scalability of metallization for advanced interconnect technologies. To overcome the challenges of plating copper in narrow structures, bottom-up filling is a prerequisite for achieving void-free and defect-free copper plating. Additives have the most significant impact on plating filling performance; the type and proportion of additives play a decisive role in the plating filling effect.
[0003] Therefore, developing an aqueous acidic copper plating solution to meet the application requirements in the manufacturing of printed circuit boards and IC substrates, as well as in the metallization of semiconductor substrates, such as TSV filling, double damask plating, copper filling with no voids, low impurity content, and smooth surface for redistribution lines or copper bumps and glass vias, has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0004] To overcome the aforementioned technical deficiencies, the present invention aims to provide a metal electroplating composition. The metal electroplating composition provided by the present invention achieves copper filling with no voids, low impurity content, and a smooth surface.
[0005] This invention discloses a metal electroplating composition comprising: copper sulfate, sulfuric acid, chloride ions, an accelerator, an inhibitor, and a leveling agent.
[0006] Optionally, the leveling agent is an imidazole-containing copolymer.
[0007] Optionally, the leveling agent may be a nitrogen-containing compound selected from the following formula:
[0008] Wherein, R is selected from methyl, propyl, propargyl, allyl, thiophene-substituted methyl, furan-substituted ethyl, monohalobenzyl, or hydroxy-substituted benzyl, pyridyl, thiophene, pyrazolyl, pyrimidinyl, indolyl, naphthyl, hydroxy-substituted phenyl, monohalophenyl, methylphenyl, or dimethylamino-substituted phenyl; or groups with the following structures:
[0009] The value of n ranges from 1 to 20.
[0010] Optionally, the leveling agent has a concentration range of 2 mg / L to 200 mg / L.
[0011] Optionally, the leveling agent has a concentration range of 50 mg / L to 100 mg / L.
[0012] Optionally, the accelerator includes one or more of the following: sodium N,N-dimethyl-dithioformamide propanesulfonate, sodium dimethylthioformylpropanesulfonate, 3-mercapto-propylsulfonate-(3-sulfopropyl) ester, sodium 3-mercapto-1-propanesulfonate, polydithiodipropanesulfonate, non-sodium polydithiodipropanesulfonic acid, 1,3-propanesulfonyl lactone, sodium salt of 3-(benzothiazolyl-s-thio)propylsulfonate, and 3-thio-isothiourea propylsulfonic acid.
[0013] Optionally, the accelerator has a concentration range of 15 mg / L to 50 mg / L.
[0014] Optionally, the accelerator has a concentration range of 20 mg / L to 40 mg / L.
[0015] Optionally, the inhibitor includes one or more of the following: polyethylene stearate, polyethylene glycol copolymer, polyethylene glycol monooleate, nonylphenol polyethylene glycol, octyl alcohol polyalkylene glycol, polypropylene glycol copolymer, polyvinyl alcohol copolymer, and polyethylene glycol / polypropylene glycol block copolymer.
[0016] Optionally, the inhibitor has a concentration range of 50 mg / L to 200 mg / L.
[0017] Optionally, the inhibitor has a concentration range of 80 mg / L to 150 mg / L.
[0018] Optionally, the weight-average molecular weight of the inhibitor is 1,000-100,000.
[0019] Optionally, the weight-average molecular weight of the inhibitor is 2000-10000.
[0020] Optionally, the copper sulfate has a concentration range of 1-250 g / L.
[0021] Optionally, the copper sulfate has a concentration range of 5-50 g / L.
[0022] Optionally, the sulfuric acid has a concentration range of 1-50 g / L.
[0023] Optionally, the sulfuric acid has a concentration range of 5-20 g / L.
[0024] Optionally, the concentration range of the chloride ions is 20-100 mg / L.
[0025] Optionally, the concentration range of the chloride ions is 40-60 mg / L.
[0026] Compared with existing technologies, the above technical solution has the following advantages:
[0027] 1. Achieve copper filling effects at advanced nodes that are free of voids and defects, have excellent uniform plating performance, low roughness, and low impurity content. Detailed Implementation
[0028] The advantages of the present invention are further illustrated below through specific embodiments, but the scope of protection of the present invention is not limited to the following embodiments.
[0029] The metal electroplating compositions of Examples 1-25 and Comparative Examples 1-6 were prepared according to the components and contents described in Table 1. All components were mixed thoroughly until homogeneous. The volume of the homogeneous electroplating composition was 1 L (diluted to 1 L with water), with water as the balance (not shown in the table). Before electroplating, the plating solution needed to be activated by applying a small current to ensure uniform distribution of the ionic components in the solution.
[0030] The leveling agent selected is shown in the following examples with the following chemical formulas:
[0031] Table 1. Electroplating solution composition of Examples 1-22 and Comparative Examples 1-3 of the present invention.
[0032] To further test the effectiveness of the aforementioned metal plating solution, xxnm trench / via wafers with TaN / Ta barrier layers and copper seed layers were electroplated under appropriate plating conditions. The filled rate, porosity, and structural density of the electroplated wafer slices were observed using FIB-SEM and TEM. The surface roughness of the plating layer was observed using AFM, and the impurity content was analyzed using SIMS. Electroplating tests were conducted on selected examples and comparative examples 1-6, and the results are shown in Table 2.
[0033] The electroplating current density is 1–20 mA / cm², preferably 3–10 mA / cm². Electroplating is performed using either a single current or multiple stepped current steps.
[0034] The electroplating temperature is 15–30℃, preferably 21–25℃.
[0035] Table 2 compares the filling effects of some examples with those of the comparative examples.
[0036] As shown in Tables 1 and 2, Examples 1-22 can achieve a copper filling effect with no voids, no defects, good uniform plating performance, low roughness, and low impurity content. Furthermore, regardless of changes in plating temperature, current density, or plating speed, a high-quality copper plating effect can be achieved.
[0037] As can be seen from Examples 1 and 2, when the base solution (copper sulfate, sulfuric acid, chloride ions) or additives are selected at the preferred concentration for electroplating, a plating effect with no voids and low impurities can be achieved. However, when any of the above components in the examples are used beyond the preferred concentration range, although a plating layer with low impurities can be obtained, slight voids will appear in the plating layer, affecting the electroplating effect.
[0038] As can be seen from Example 1 and Comparative Example 1, in the presence of copper sulfate, sulfuric acid, chloride ions, accelerators and leveling agents, using L1 as an inhibitor results in better electroplating than using polyurethane biguanide, with no voids and very low impurity content.
[0039] As can be seen from Examples 1, 13 and Comparative Example 3, when using L1 and L2 of the present invention as inhibitors, the electroplating effect is better than that of using polyammonium salt-2 when the copper sulfate, sulfuric acid, chloride ions, accelerator and leveling agent are the same, and the effect of achieving a bright surface, no voids and low impurity content can be achieved.
[0040] As can be seen from Example 20 and Comparative Example 2, using L4 of the present invention as an inhibitor, even in low-concentration copper base solution, it is still possible to achieve a bright surface, no voids and low impurity content.
[0041] In summary, the electroplating solution of this application can achieve a copper filling effect on advanced nodes that is free of voids and defects, has excellent uniform plating performance, low roughness, and low impurity content.
[0042] 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, include: Copper sulfate, sulfuric acid, chloride ions, accelerators, inhibitors, and leveling agents.
2. The metal electroplating composition according to claim 1, characterized in that, The leveling agent is an imidazole-containing copolymer.
3. The metal electroplating composition according to claim 2, characterized in that, The leveling agent is selected from nitrogen-containing compounds with the following formula: Wherein, R is selected from methyl, propyl, benzyl, propargyl, allyl, thiophene-substituted methyl, furan-substituted ethyl, monohalobenzyl, or hydroxy-substituted benzyl, pyridyl, thiophene, pyrazolyl, pyridinyl, indolyl, naphthyl, hydroxy-substituted naphthyl, phenyl, hydroxy-substituted phenyl, monohalophenyl, methylphenyl, nitrophenyl, methoxyphenyl, or dimethylamino-substituted phenyl; or groups with the following structures: The value of n ranges from 1 to 20.
4. The metal electroplating composition according to claim 1, characterized in that, The leveling agent has a concentration range of 2 mg / L to 200 mg / L.
5. The metal electroplating composition according to claim 4, characterized in that, The leveling agent has a concentration range of 50 mg / L to 100 mg / L.
6. The metal electroplating composition according to claim 1, characterized in that, The accelerator includes one or more of the following: sodium N,N-dimethyl-dithioformamide propanesulfonate, sodium dimethylthioformylpropanesulfonate, 3-mercapto-propylsulfonate-(3-sulfopropyl) ester, sodium 3-mercapto-1-propanesulfonate, polydithiodipropanesulfonate, sodium-free polydithiodipropanesulfonic acid, 1,3-propanesulfonyl lactone, sodium salt of 3-(benzothiazolyl-s-thio)propylsulfonate, and 3-thio-isothiourea propylsulfonic acid.
7. The metal electroplating composition according to claim 6, characterized in that, The accelerator has a concentration range of 15 mg / L to 50 mg / L.
8. The metal electroplating composition according to claim 7, characterized in that, The accelerator has a concentration range of 20 mg / L to 40 mg / L.
9. The metal electroplating composition according to claim 1, characterized in that, The inhibitors include one or more of the following: carboxymethyl cellulose, polyethylene stearate, polyethylene glycol copolymer, polyethylene glycol monooleate, nonylphenol polyethylene glycol, octanol polyalkylene glycol, polypropylene glycol copolymer, and polyethylene glycol / polypropylene glycol block copolymer.
10. The metal electroplating composition according to claim 9, characterized in that, The inhibitor has a concentration range of 50 mg / L to 200 mg / L.
11. The metal plating composition as claimed in claim 10, characterized in that, The inhibitor has a concentration range of 80 mg / L to 150 mg / L.
12. The metal electroplating composition according to claim 9, characterized in that, The weight-average molecular weight of the inhibitor is 1,000-100,000.
13. The metal electroplating composition according to claim 12, characterized in that, The weight-average molecular weight of the inhibitor is 2000-10000.
14. The metal electroplating composition according to claim 1, characterized in that, The copper sulfate has a concentration range of 1-250 g / L.
15. The metal plating composition as described in claim 14, characterized in that, The copper sulfate has a concentration range of 5-50 g / L.
16. The metal electroplating composition according to claim 1, characterized in that, The sulfuric acid has a concentration range of 1-50 g / L.
17. The metal plating composition as claimed in claim 16, characterized in that, The sulfuric acid has a concentration range of 5-20 g / L.
18. The metal electroplating composition according to claim 1, characterized in that, The concentration range of the chloride ions is 20-100 mg / L.
19. The metal electroplating composition as claimed in claim 18, characterized in that, The concentration of chloride ions is in the range of 40-60 mg / L.