A nano-twinned copper electroplating additive and electroplating solution

Abstract

This invention discloses a nanotwinned copper electroplating additive and an electroplating solution. In the nanotwinned copper electroplating additive, the mass fraction of components with a molecular weight above 100,000 Da is 0-20%, and the mass fraction of components with a molecular weight below 10,000 Da is 30%-100%. The additive of this invention has excellent and stable twinning promoting effect, improving the process stability and repeatability of nanotwinned copper electroplating and broadening the electroplating process window. Electroplating using a nanotwinned copper electroplating solution containing this additive can obtain a (111) preferred orientation nanotwinned copper coating with good uniformity, excellent performance, and a preference degree greater than 95%, which is beneficial for applications in electronic packaging and semiconductor manufacturing.

Description

Technical Field

[0001] This invention relates to the field of electroplating technology, and more specifically, to a nano-twinned copper electroplating additive and electroplating solution. Background Technology

[0002] Nanotwinned copper is a copper material with a nanoscale twinned crystalline structure within its grains. It possesses high electrical conductivity, mechanical properties, resistance to electromigration, and stability, making it a promising candidate for applications in electronic packaging and semiconductor manufacturing. Due to its superior electrical and mechanical properties, nanotwinned copper is becoming a key technology for overcoming current bottlenecks in copper electroplating.

[0003] CN102400188B discloses a nanotwinned copper material with a (111) texture, prepared by direct current electrodeposition. The electroplating solution consists of 150–200 g / L copper sulfate, pH adjusted to 0.5–1.5, and 2.5–15 mL / L of 0.2–0.5 wt% gelatin aqueous solution and 0.2–1.0 mL / L of 5–25 wt% NaCl aqueous solution. CN114875461B discloses a direct current electroplating method for nanotwinned copper material, wherein the electroplating solution consists of 20–70 g / L copper ions, 20–200 g / L sulfuric acid, 20–80 ppm chloride ions, 5–200 ppm gelatin, 0.5–100 mmol / L nickel ions, and the balance being water. All of the above patents use gelatin as an additive in nanotwinned copper electroplating solutions. The addition of gelatin can help electroplated copper grow nanotwinned structures and improve the smoothness and gloss of the plating layer.

[0004] However, gelatin is a mixture of polypeptide chains with varying molecular weights, ranging from several thousand to hundreds of thousands. Depending on the hydrolysis method used in its preparation, gelatin can be classified into acid-processed gelatin, alkali-processed gelatin, and enzymatically processed gelatin. The raw materials for gelatin are also diverse, including animal tissues such as pigskin, cowhide, fish skin, and bones. In the actual preparation of nanotwinned copper, using gelatin as an electroplating additive often results in unstable processes and poor reproducibility, making it difficult to consistently obtain nanotwinned structures and limiting the application of gelatin in nanotwinned copper electroplating. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned defects in the prior art and provide a nano-twinned copper electroplating additive and electroplating solution. The nano-twinned copper electroplating additive has excellent and stable twinning promotion effect, which improves the process stability and repeatability of nano-twinned copper electroplating and broadens the electroplating process window. Electroplating with a nano-twinned copper electroplating solution containing the additive can obtain a (111) preferred orientation nano-twinned copper coating with good uniformity, excellent performance and a preference degree greater than 95%.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] The first aspect of this invention provides a nano-twinned copper electroplating additive, which is obtained by hydrolyzing or separating collagen, gelatin, or their derivatives; the composition of the nano-twinned copper electroplating additive needs to meet the following requirements:

[0008] The mass fraction of components with a molecular weight of 100,000 Da or higher is 0–20%.

[0009] The mass fraction of components with a molecular weight below 10000 Da is 30% to 100%.

[0010] The rest are components with molecular weights of 10,000 to 100,000 Da.

[0011] Preferably, in the composition of the nanotwinned copper electroplating additive, the mass fraction of the component with a molecular weight of 100,000 Da or higher is 0-10%, the mass fraction of the component with a molecular weight of 10,000 Da or lower is 50%-100%, and the remainder is a component with a molecular weight of 10,000-100,000 Da.

[0012] In the above technical solution, the gelatin further includes any one or more of acid-processed gelatin, alkali-processed gelatin, and enzymatic gelatin.

[0013] In the above technical solution, the hydrolysis method further includes any one or more of acid-catalyzed hydrolysis, alkali-catalyzed hydrolysis, and enzyme-catalyzed hydrolysis; the separation method includes any one or more of ultrafiltration, dialysis, molecular sieve, gel filtration, and electrophoresis.

[0014] A second aspect of the present invention provides a nanotwinned copper electroplating solution, wherein the nanotwinned copper electroplating solution includes the aforementioned nanotwinned copper electroplating additives.

[0015] In the above technical solution, the nanotwinned copper electroplating solution further includes copper ions, sulfuric acid, chloride ions, and the nanotwinned copper electroplating additives described above.

[0016] In the above technical solution, the concentration of copper sulfate in the nano-twinned copper electroplating solution is 20-80 g / L; preferably, the concentration of copper ions in the nano-twinned copper electroplating solution is 28-64 g / L; preferably, the copper ions are derived from copper sulfate.

[0017] In the above technical solution, the concentration of sulfuric acid in the nano-twinned copper electroplating solution is further 5-180 g / L; preferably, the concentration of sulfuric acid in the nano-twinned copper electroplating solution is 10-150 g / L.

[0018] In the above technical solution, the concentration of chloride ions in the nano-twinned copper electroplating solution is further 3-100 mg / L; preferably, the concentration of chloride ions in the nano-twinned copper electroplating solution is 10-60 mg / L; preferably, the chloride ions in the nano-twinned copper electroplating solution can be provided by hydrochloric acid and / or sodium chloride.

[0019] In the above technical solution, the concentration of the additive in the nano-twinned copper electroplating solution is further 5-300 mg / L; preferably, the concentration of the additive in the nano-twinned copper electroplating solution is 30-200 mg / L.

[0020] A third aspect of the present invention provides a method for electroplating nanotwinned copper, the method comprising: electroplating on a substrate using the nanotwinned copper electroplating solution as described above, to obtain the nanotwinned copper.

[0021] In the above technical solution, the electroplating preparation method further includes: the substrate serving as the cathode, the anode including a soluble anode (e.g., a phosphorus copper anode) or an insoluble anode (e.g., a platinum electrode), using the nanotwinned copper electroplating solution, at an electroplating temperature of 10–60°C and an electroplating current density of 1–40 A / dm³. 2 Electroplating is performed at a stirring speed of 400–1500 rpm to obtain the nano-twinned copper; the substrate is a conductive material, such as copper, titanium, gold, nickel, aluminum or their alloys.

[0022] The fourth aspect of this invention provides a nanotwinned copper, which is prepared by the above-described electroplating method.

[0023] In the above technical solution, the nanotwinned copper further has a strong (111) preferred orientation, with a (111) preference degree greater than 95%; the nanotwinned copper contains columnar crystals perpendicular to the substrate; the diameter of the columnar crystals is 0.1 to 20 μm; the interior of the nanotwinned copper contains high-density horizontal twins, and the thickness of the twin wafer layer of the horizontal twins is 1 to 100 nm.

[0024] The fifth aspect of the present invention provides the application of the nanotwinned copper electroplating additive and the nanotwinned copper electroplating solution described above in electronic packaging and semiconductor manufacturing.

[0025] During copper electrodeposition, gelatin-based additives undergo periodic adsorption and desorption on the cathode surface, leading to potential oscillations and subsequent periodic stress accumulation and relaxation, thus forming a twinned structure. This invention reveals that high molecular weight (above 100,000 Da) gelatin-based additives, due to their numerous adsorption sites and strong cathode binding, cannot undergo timely desorption, significantly inhibiting the formation of nanotwinned structures. Low molecular weight (below 10,000 Da) additives, with fewer adsorption sites and weaker cathode binding, readily undergo periodic adsorption and desorption, thus exhibiting a significant twinning-promoting effect. While other medium molecular weight (10,000–100,000 Da) additives can also produce periodic adsorption and desorption, their effect is significantly weaker than that of low molecular weight (below 10,000 Da) additives, resulting in a relatively weak twinning-promoting effect. Therefore, this invention proposes to reduce the proportion of high molecular weight (above 100,000 Da) components with twinning inhibition effect, while increasing the proportion of low molecular weight (below 10,000 Da) components with twinning promotion effect, so that the additive with this specific composition can play an excellent and stable twinning promotion effect, improve the process stability and repeatability of nanotwinned copper electroplating, and broaden the electroplating process window. By using a nanotwinned copper electroplating solution containing this additive for electroplating, it is possible to obtain a (111) preferred orientation nanotwinned copper coating with good uniformity, excellent performance and a preference degree greater than 95%.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The nano-twinned copper electroplating additive provided by the present invention has excellent and stable twinning promotion effect, which improves the process stability and repeatability of nano-twinned copper electroplating, and broadens the process window of electroplating. Electroplating with nano-twinned copper electroplating solution containing the additive can obtain a nano-twinned copper coating with excellent performance.

[0028] (2) The nano-twin copper coating prepared by the present invention has good uniformity of structure and strong (111) preferred orientation, with a (111) preference degree greater than 95%. It contains columnar crystals perpendicular to the substrate and high-density horizontal twins inside the grains. The nano-twin copper coating has the characteristics of high conductivity, mechanical properties, high electromigration resistance, oxidation resistance and thermal stability. It can be applied to the fields of electronic packaging, integrated circuit manufacturing and other technologies, including wafer-level electroplating, substrate, carrier and PCB and other application scenarios that require electroplating. Attached Figure Description

[0029] Figure 1 This is a FIB diagram of the cross-sectional microstructure of the nanotwinned copper coating obtained in Example 1 along the growth direction.

[0030] Figure 2(a) is the EBSD IPF orientation diagram of the top microstructure of the nanotwinned copper coating prepared in Example 1. Figure 2 (b) is the EBSD inverse pole diagram of the microstructure of the top of the nanotwinned copper coating prepared in Example 1.

[0031] Figure 3 (a) is the EBSD IPF orientation diagram of the top microstructure of the nanotwinned copper coating prepared in Example 2. Figure 3 (b) is the EBSD inverse pole diagram of the microstructure of the top of the nanotwinned copper coating prepared in Example 2.

[0032] Figure 4 (a) is the EBSD IPF orientation diagram of the top microstructure of the nanotwinned copper coating prepared in Example 3. Figure 4 (b) is the EBSD inverse pole diagram of the microstructure of the top of the nanotwinned copper coating prepared in Example 3.

[0033] Figure 5 (a) is the EBSD IPF orientation diagram of the top microstructure of the nanotwinned copper coating prepared in Example 4. Figure 5 (b) is the EBSD inverse pole diagram of the microstructure of the top of the nanotwinned copper coating prepared in Example 4.

[0034] Figure 6 The image shows the FIB diagram of the cross-sectional microstructure of the copper coating obtained in Comparative Example 1 along the growth direction.

[0035] Figure 7 (a) is the EBSD IPF orientation diagram of the microstructure of the top of the copper plating layer obtained in Comparative Example 1. Figure 7 (b) is the EBSD inverse pole figure of the microstructure of the top of the copper plating obtained in Comparative Example 1.

[0036] Figure 8 (a) is the EBSD IPF orientation diagram of the microstructure of the top of the copper plating obtained in Comparative Example 2. Figure 8 (b) is the EBSD inverse pole diagram of the microstructure of the top of the copper plating obtained in Comparative Example 2.

[0037] Figure 9 (a) is the EBSD IPF orientation diagram of the microstructure of the top of the copper plating obtained in Comparative Example 3. Figure 9 (b) is the EBSD inverse pole diagram of the microstructure of the top of the copper plating obtained in Comparative Example 3.

[0038] Figure 10 (a) is the EBSD IPF orientation diagram of the microstructure of the top of the copper plating obtained in Comparative Example 4. Figure 10 (b) is the EBSD inverse pole figure of the microstructure of the top of the copper plating obtained in Comparative Example 4.

[0039] Figure 11 (a) is an EBSD IPF orientation diagram of the microstructure of the top of the copper plating layer prepared in Comparative Example 5. Figure 11 (b) is the EBSD inverse pole diagram of the microstructure of the top of the copper plating obtained in Comparative Example 5.

[0040] Figure 12 (a) is an EBSD IPF orientation diagram of the microstructure of the top of the copper plating layer prepared in Comparative Example 6. Figure 12 (b) is an EBSD inverse pole diagram of the microstructure of the top of the copper plating obtained in Comparative Example 6. Detailed Implementation

[0041] The present invention will be further described below with reference to specific embodiments, but this does not limit the present invention in any way.

[0042] Example 1

[0043] A nano-twinned copper electroplating additive is prepared by means of: weighing 1g of alkaline gelatin derived from cowhide and dissolving it in 100mL of deionized water, heating it in a water bath to 60℃ and stirring to completely dissolve it, thereby obtaining a gelatin solution; ultrafiltration of the gelatin solution using an ultrafiltration membrane with a molecular weight cutoff of 50,000 Da to obtain the nano-twinned copper electroplating additive, wherein the mass fraction of the component with a molecular weight of more than 100,000 Da is 3%, the mass fraction of the component with a molecular weight of less than 10,000 Da is 70%, and the remainder is the component with a molecular weight of 10,000 to 100,000 Da.

[0044] A nanotwinned copper electroplating solution comprises the following components: 70 g / L copper sulfate, 150 g / L sulfuric acid, 20 ppm chloride ions, and 50 ppm of the nanotwinned copper electroplating additive provided in this embodiment; the solvent is deionized water; wherein the chloride ions are provided by sodium chloride. The preparation method of the nanotwinned copper electroplating solution includes: mixing copper sulfate, sulfuric acid, sodium chloride, the nanotwinned copper electroplating additive provided in this embodiment, and deionized water according to the aforementioned proportions, stirring until homogeneous, to obtain the nanotwinned copper electroplating solution.

[0045] Nanotwinned copper was prepared by electroplating using the nanotwinned copper electroplating solution provided in this embodiment. A titanium plate was used as the cathode, and a soluble phosphorus copper anode was used. Both were immersed in the nanotwinned copper electroplating solution provided in this embodiment for electroplating. The electroplating conditions were: constant temperature 25℃, current density 3A / dm³. 2 The magnetic stirring speed is 600 rpm.

[0046] The cross-sectional microstructure of the nanotwinned copper coating prepared in this embodiment along its growth direction is as follows: Figure 1As shown, the cross-sectional microstructure of the nanotwinned copper coating consists of columnar crystals perpendicular to the substrate, with a diameter of approximately 2–4 μm. High-density horizontal twins exist within the grains, and the thickness of the twinned lamellae is 50 nm. The crystal orientation information of the nanotwinned copper coating can be obtained using electron backscatter diffraction (ESD) technology, such as… Figure 2 As shown, the prepared nanotwinned copper coating has a strong (111) preferred orientation, with a (111) preference degree of 98.6%.

[0047] Example 2

[0048] A nano-twinned copper electroplating additive is prepared by means of: weighing 0.5g of collagen and dissolving it in 100mL of deionized water, heating it in a water bath to 60℃ and stirring to completely dissolve it, to obtain a collagen solution; adding sodium hydroxide to adjust the pH to 10-12, heating it to 90℃, and hydrolyzing it for 20h under stirring to obtain the nano-twinned copper electroplating additive, wherein the mass fraction of the component with a molecular weight of more than 100,000 Da is 16%, the mass fraction of the component with a molecular weight of less than 10,000 Da is 35%, and the remainder is the component with a molecular weight of 10,000-100,000 Da.

[0049] A nanotwinned copper electroplating solution comprises the following components: 90 g / L copper sulfate, 120 g / L sulfuric acid, 30 ppm chloride ions, and 60 ppm of the nanotwinned copper electroplating additive provided in this embodiment; the solvent is deionized water; wherein the chloride ions are provided by sodium chloride. The preparation method of the nanotwinned copper electroplating solution includes: mixing copper sulfate, sulfuric acid, sodium chloride, the nanotwinned copper electroplating additive provided in this embodiment, and deionized water according to the aforementioned proportions, stirring until homogeneous, to obtain the nanotwinned copper electroplating solution.

[0050] Nanotwinned copper was prepared by electroplating using the nanotwinned copper electroplating solution provided in this embodiment. A titanium plate was used as the cathode, and a soluble phosphorus copper anode was used. Both were immersed in the nanotwinned copper electroplating solution provided in this embodiment for electroplating. The electroplating conditions were: constant temperature 30℃, current density 5A / dm³. 2 The magnetic stirring speed is 1000 rpm.

[0051] The nanotwinned copper coating prepared in this embodiment contains columnar crystals perpendicular to the substrate, with a diameter of approximately 2–3 μm. High-density horizontal twins exist within the grains, and the thickness of the twinned wafer layer is 52 nm. The coating exhibits a strong (111) preferred orientation, with a (111) preference degree of 97.8%. Figure 3 As shown.

[0052] Example 3

[0053] A nano-twinned copper electroplating additive is prepared by means of: weighing 1g of acid-processed gelatin derived from pigskin and dissolving it in 100mL of deionized water, heating it in a water bath to 60℃ and stirring until it is completely dissolved to obtain a gelatin solution; adding sulfuric acid to adjust the pH to 1-2, heating it to 80℃, and hydrolyzing it for 6h under stirring to obtain the nano-twinned copper electroplating additive, wherein the mass fraction of the component with a molecular weight of more than 100,000 Da is 8%, the mass fraction of the component with a molecular weight of less than 10,000 Da is 65%, and the remainder is the component with a molecular weight of 10,000 to 100,000 Da.

[0054] A nanotwinned copper electroplating solution comprises the following components: 100 g / L copper sulfate, 100 g / L sulfuric acid, 50 ppm chloride ions, and 80 ppm of the nanotwinned copper electroplating additive provided in this embodiment; the solvent is deionized water; wherein the chloride ions are provided by sodium chloride. The preparation method of the nanotwinned copper electroplating solution includes: mixing copper sulfate, sulfuric acid, sodium chloride, the nanotwinned copper electroplating additive provided in this embodiment, and deionized water according to the aforementioned proportions, stirring until homogeneous, to obtain the nanotwinned copper electroplating solution.

[0055] Nanotwinned copper was prepared by electroplating using the nanotwinned copper electroplating solution provided in this embodiment. A copper plate was used as the cathode, and a soluble phosphorus copper anode was used. Both were immersed in the nanotwinned copper electroplating solution provided in this embodiment for electroplating. The electroplating conditions were: constant temperature 30℃, current density 6A / dm³. 2 The magnetic stirring speed is 900 rpm.

[0056] The nanotwinned copper coating prepared in this embodiment contains columnar crystals perpendicular to the substrate, with a diameter of approximately 1–3 μm. High-density horizontal twins exist within the grains, and the thickness of the twinned wafer layer is 62 nm. The coating exhibits a strong (111) preferred orientation, with a (111) preference degree of 96.9%. Figure 4 As shown.

[0057] Example 4

[0058] A nano-twinned copper electroplating additive is prepared by means of: weighing 1g of enzymatically processed gelatin derived from fish skin and dissolving it in 100mL of deionized water, heating it in a water bath to 60℃ and stirring until it is completely dissolved to obtain a gelatin solution; adjusting the pH to 7-8, maintaining the temperature at 37℃, and hydrolyzing it for 10h in the presence of trypsin to obtain the nano-twinned copper electroplating additive, wherein the mass fraction of the component with a molecular weight of more than 100,000 Da is 0, the mass fraction of the component with a molecular weight of less than 10,000 Da is 90%, and the remainder is the component with a molecular weight of 10,000 to 100,000 Da.

[0059] A nanotwinned copper electroplating solution comprises the following components: 130 g / L copper sulfate, 60 g / L sulfuric acid, 60 ppm chloride ions, and 100 ppm of the nanotwinned copper electroplating additive provided in this embodiment; the solvent is deionized water; wherein the chloride ions are provided by sodium chloride. The preparation method of the nanotwinned copper electroplating solution includes: mixing copper sulfate, sulfuric acid, sodium chloride, the nanotwinned copper electroplating additive provided in this embodiment, and deionized water according to the aforementioned proportions, stirring until homogeneous, to obtain the nanotwinned copper electroplating solution.

[0060] Nanotwinned copper was prepared by electroplating using the nanotwinned copper electroplating solution provided in this embodiment. A titanium plate was used as the cathode, and an insoluble platinum electrode was used as the anode. Both electrodes were immersed in the nanotwinned copper electroplating solution provided in this embodiment for electroplating. The electroplating conditions were: constant temperature 40℃, current density 10 A / dm³. 2 The magnetic stirring speed is 1200 rpm.

[0061] The nanotwinned copper coating prepared in this embodiment contains columnar crystals perpendicular to the substrate, with a diameter of approximately 1–2 μm. High-density horizontal twins exist within the grains, and the thickness of the twinned crystalline layer is 75 nm. The coating exhibits a strong (111) preferred orientation, with a (111) preference degree of 97.4%. Figure 5 As shown.

[0062] Comparative Example 1

[0063] The only difference between this comparative example and Example 1 is that the nanotwinned copper electroplating additive in the nanotwinned copper electroplating solution is unseparated alkaline gelatin derived from cowhide, with a mass fraction of 70% for components with a molecular weight of 100,000 Da or higher, a mass fraction of 5% for components with a molecular weight of less than 10,000 Da, and the remainder being components with a molecular weight of 10,000 to 100,000 Da.

[0064] The cross-sectional microstructure of the copper plating layer prepared using the nanotwinned copper electroplating solution of this comparative example along the growth direction is as follows: Figure 6 As shown, the copper plating does not contain twinned structures, and the crystal orientation is as follows. Figure 7 As shown, the obtained copper plating layer has a random orientation and a small grain size.

[0065] Comparative Example 2

[0066] The only difference between this comparative example and Example 2 is that the nanotwinned copper electroplating additive in the nanotwinned copper electroplating solution is collagen that has not been catalyzed by alkali hydrolysis. The mass fraction of the component with a molecular weight of 100,000 Da or higher is 95%, the mass fraction of the component with a molecular weight of less than 10,000 Da is 0%, and the remainder is the component with a molecular weight of 10,000 to 100,000 Da.

[0067] The copper plating solution used in this comparative example, a nanotwinned copper plating layer was prepared with random orientation, fine grain size, and no twinned structure, such as... Figure 8 As shown.

[0068] Comparative Example 3

[0069] The only difference between this comparative example and Example 2 is that the nanotwinned copper electroplating additive in the nanotwinned copper electroplating solution is collagen that has undergone alkaline catalytic hydrolysis. The mass fraction of the component with a molecular weight of 100,000 Da or higher is 15%, the mass fraction of the component with a molecular weight of less than 10,000 Da is 25%, and the remainder is the component with a molecular weight of 10,000 to 100,000 Da.

[0070] The copper plating solution used in this comparative example, a nanotwinned copper plating layer was prepared with random orientation, fine grain size, and no twinned structure, such as... Figure 9 As shown.

[0071] Comparative Example 4

[0072] The only difference between this comparative example and Example 3 is that the nanotwinned copper electroplating additive in the nanotwinned copper electroplating solution is acid gelatin derived from pigskin that has not undergone acid-catalyzed hydrolysis. The mass fraction of the component with a molecular weight of 100,000 Da or higher is 50%, the mass fraction of the component with a molecular weight of less than 10,000 Da is 20%, and the remainder is the component with a molecular weight of 10,000 to 100,000 Da.

[0073] The copper plating solution used in this comparative example, a nanotwinned copper plating layer was prepared with random orientation, fine grain size, and no twinned structure, such as... Figure 10 As shown.

[0074] Comparative Example 5

[0075] The only difference between this comparative example and Example 3 is that the nanotwinned copper electroplating additive in the nanotwinned copper electroplating solution is acid-catalyzed hydrolyzed gelatin derived from pigskin. The mass fraction of the component with a molecular weight of 100,000 Da or higher is 35%, the mass fraction of the component with a molecular weight of less than 10,000 Da is 50%, and the remainder is a component with a molecular weight of 10,000 to 100,000 Da.

[0076] The copper plating solution used in this comparative example, a nanotwinned copper plating layer was prepared with random orientation, fine grain size, and no twinned structure, such as... Figure 11 As shown.

[0077] Comparative Example 6

[0078] The only difference between this comparative example and Example 4 is that the nanotwinned copper electroplating additive in the nanotwinned copper electroplating solution is enzymatic gelatin derived from fish skin that has not undergone trypsin-catalyzed hydrolysis. The mass fraction of the component with a molecular weight above 100,000 Da is 60%, the mass fraction of the component with a molecular weight below 10,000 Da is 20%, and the remainder is a component with a molecular weight between 10,000 and 100,000 Da. Figure 12 As shown.

[0079] The copper plating solution of this comparative example, which is a nanotwinned copper plating solution, produces a copper plating layer with random orientation, small grain size, and no twinned structure.

[0080] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A nano-twinned copper electroplating solution, characterized in that, The nanotwinned copper electroplating solution includes nanotwinned copper electroplating additives; the nanotwinned copper electroplating solution includes copper ions, sulfuric acid, and chloride ions; The nano-twinned copper electroplating additive is obtained by hydrolyzing or separating collagen, gelatin or their derivatives; the components of the nano-twinned copper electroplating additive need to meet the following requirements: the mass fraction of components with a molecular weight of 100,000 Da or above is 0 to 20%; the mass fraction of components with a molecular weight of less than 10,000 Da is 30% to 90%; and the remainder is components with a molecular weight of 10,000 to 100,000 Da.

2. The nanotwinned copper electroplating solution according to claim 1, characterized in that, The components of the nanotwinned copper electroplating additive need to meet the following requirements: the mass fraction of components with a molecular weight of 100,000 Da or higher is 0 to 10%, the mass fraction of components with a molecular weight of less than 10,000 Da is 50% to 90%, and the remainder is components with a molecular weight of 10,000 to 100,000 Da.

3. The nanotwinned copper electroplating solution according to claim 1, characterized in that, The gelatin includes one or more of acid-processed gelatin, alkali-processed gelatin, and enzymatic gelatin; the hydrolysis method includes one or more of acid-catalyzed hydrolysis, alkali-catalyzed hydrolysis, and enzymatic hydrolysis; the separation method includes one or more of ultrafiltration, dialysis, molecular sieve, gel filtration, and electrophoresis.

4. The nanotwinned copper electroplating solution according to claim 1, characterized in that, The concentration of copper ions in the nano-twinned copper electroplating solution is 20–80 g / L; the concentration of sulfuric acid in the nano-twinned copper electroplating solution is 5–180 g / L; the concentration of chloride ions in the nano-twinned copper electroplating solution is 3–100 mg / L; and the concentration of additives in the nano-twinned copper electroplating solution is 5–300 mg / L.

5. The nanotwinned copper electroplating solution according to claim 4, characterized in that, The copper ions are derived from copper sulfate; the chloride ions are derived from hydrochloric acid and / or sodium chloride.

6. A method for electroplating nanotwinned copper, characterized in that, The electroplating preparation method includes: electroplating on a substrate using the nanotwinned copper electroplating solution as described in any one of claims 1-5 to obtain the nanotwinned copper.

7. The electroplating preparation method according to claim 6, characterized in that, The electroplating temperature is 10–60°C; the stirring speed of the electroplating solution is 400–1500 rpm; and the electroplating current density is 1–40 A / dm³. 2 .

8. The application of the nanotwinned copper electroplating solution as described in any one of claims 1-5 in electronic packaging and semiconductor manufacturing.

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