Leveling agents, compositions, and applications thereof

Abstract

A leveling agent is provided that is a polypyridine compound. The polypyridine compound comprises a structural unit of formula (I) or a protonated product of a structural unit of formula (I): [Formula 1] TIFF2025531708000036.tif27170 In formula (I), R1 and R2 are independently any one of substituted or unsubstituted alkylene, substituted or unsubstituted arylene, substituted or unsubstituted arylene alkyl, substituted or unsubstituted alkylene aryl, alkylene containing an ether oxygen atom, an ester, and / or an imide, arylene containing an ether oxygen atom, an ester, and / or an imide, and alkylene aryl containing an ether oxygen atom, an ester, and / or an imide; and R3 is any one of a single bond, substituted or unsubstituted alkylene, substituted or unsubstituted arylene, substituted or unsubstituted arylene alkyl, and substituted or unsubstituted alkylene aryl.

Description

[Technical Field]

[0002] Embodiments of the present application relate to the field of metal electroplating technology, and more particularly to leveling agents, compositions, and their applications. [Background technology]

[0003] In the manufacturing processes of the electronics industry, metallic copper is widely used as an interconnecting material in fields such as integrated circuits, electronic packages, and printed circuit boards due to its characteristics such as good conductivity and good ductility. Filling holes or grooves, such as grooves, plated through-holes, or blind via holes of different sizes, with electroplated copper is completed through the electroplating process, and as a result, electrical interconnection between copper wires and interlayer structures can be implemented. [Overview of the project] [Problems that the invention aims to solve]

[0004] However, in the process of electroplating copper into holes or grooves, the current distribution inside and outside the hole becomes uneven, and a discharge effect occurs at the tip of the hole's apex, resulting in different copper deposition rates inside and outside the hole. As a result, the electroplated copper layer tends to pre-seal the hole and develop internal defects, including voids (shown in Figure 1a) and seams (shown in Figure 1b). This affects the reliability of the interconnect structure. To eliminate the aforementioned defects, suitable additives are usually added to the electroplating solution to change the polarization potential of the electrode surface. This controls the copper deposition rate in different regions inside and outside the hole, achieving an effect where "deposition is promoted at the bottom of the hole and suppressed at the top of the hole" when filling the hole or groove with electroplated copper, ultimately resulting in defect-free superfilling (as shown in Figure 1c). However, even after superfilling the hole or groove, copper continues to deposit at the top of the pattern, resulting in bump defects at the top, as shown in Figures 1a, 1b, and 1c. As a result, during the filling of holes or grooves across the entire substrate, the thickness difference between the copper layer in the high-density interconnect pattern region and the copper layer in the low-density interconnect pattern region becomes large, thus forming a non-flat copper layer as shown in Figure 2. This negatively impacts the subsequent chemical mechanical polishing (CMP) process. Furthermore, as the feature size of integrated circuit processes becomes smaller, it becomes more difficult to obtain a defect-free, highly flat electroplated interconnect layer, and the demands on the chemicals of the electroplating solution used to fill small grooves are increasing. Therefore, there is a need to provide an additive. This additive can suppress copper deposition to some extent, facilitating defect-free filling, while also planarizing and homogenizing the surface of the plating layer, reducing the thickness difference between the copper layer in the high-density interconnect pattern region and the copper layer in the low-density interconnect pattern region, and facilitating the subsequent CMP process. This enables the realization of defect-free filling with high surface flatness. [Means for solving the problem]

[0005] From this viewpoint, one embodiment of the present application provides a leveling agent. An electroplating composition using the leveling agent is used to fill interconnection structures in an electronic substrate, thereby enabling defect-free metal filling of small holes or grooves, resulting in improved surface flatness of the metal plating layer obtained in distributed regions with different densities, suppression of impurity content in the plating layer, which in turn facilitates chemical and mechanical polishing and improves the reliability of the plating layer.

[0006] Specifically, in a first embodiment of the present invention, a leveling agent for use in metal electroplating is provided. The leveling agent is a polypyridine compound, which comprises a structural unit shown in formula (I), or a protonated product of the structural unit shown in formula (I).

[0007] [ka] Equation (I) In formula (I), R1 and R2 are independently one of the following: a substituted or unsubstituted alkylene, a substituted or unsubstituted arylene, a substituted or unsubstituted arylenealkyl, a substituted or unsubstituted alkylenearyl, an alkylene containing an ether oxygen atom, an ester, and / or imide, an arylene containing an ether oxygen atom, an ester, and / or imide, an arylenealkyl, an ether oxygen atom, an ester, and / or imide, and an alkylenearyl containing an ether oxygen atom, an ester, and / or imide; and R3 is one of the following: a single bond, a substituted or unsubstituted alkylene, a substituted or unsubstituted arylene, a substituted or unsubstituted arylenealkyl, a substituted or unsubstituted alkylenearyl, and a bonding group containing an ether oxygen atom, an ester, and / or imide. The leveling agent in this embodiment of the present application is a polypyridine compound containing an ester in particular. Leveling agents are added to electroplating compositions and used to fill holes or grooves with electroplated metal in semiconductor manufacturing processes, preventing excessive metal deposition to some extent. This ensures defect-free metal filling of holes or grooves, preventing relatively small holes or grooves from being completely filled beforehand. The difference in thickness between electroplated metal layers in distribution areas with different densities is reduced, significantly suppressing platform waviness on the surface of the plating layer, resulting in a better planarization effect, which facilitates subsequent CMP processes. Furthermore, the amount of impurities in the plating layer is reduced, improving the reliability of the plating layer.

[0008] In embodiments of the present application, the polypyridine compound comprises a protonation product of the structural unit represented by formula (I) and a halide ion. In embodiments of the present application, the halide ion comprises one of the following: a fluoride ion, a chloride ion, a bromide ion, and an iodide ion. The protonation product of the structural unit represented by formula (I) may be represented as formula (I-1). It can be understood that each substituent in formula (I-1) corresponds to the corresponding substituent in formula (I).

[0009] [ka] Equation (I-1) In the embodiments of the present application, in R1, R2, and R3, the amount of carbon atoms in the substituted or unsubstituted alkylene is in the range of 1 to 30, and the amount of carbon atoms in the substituted or unsubstituted arylene is in the range of 6 to 30.

[0010] In some embodiments of the present application, R1 may be an alkylene containing one or more ether oxygen atoms, an arylene containing one or more ether oxygen atoms, an arylene alkyl containing one or more ether oxygen atoms, or an alkylenearyl containing one or more ether oxygen atoms. R1 is a group containing ether oxygen atoms, in which case excess deposition of metal is better suppressed, the difference in thickness between electroplated metal layers in distribution regions having different densities is reduced, and a better planarization effect can be obtained.

[0011] In the embodiments of the present application, the alkylene containing an ether oxygen atom is -(R4O) x -L-(R5O) y -R5- It is represented as, Here, R4 and R5 are the same or different alkylenes, x is a non-negative integer, y is a non-negative integer, and L represents a single bond or at least one ether oxygen block.

[0012] In embodiments of the present application, the values ​​of x and y may be in the range of 1 to 300. In some embodiments, the values ​​of x and y may be in the range of 1 to 100. In some embodiments, the values ​​of x and y may be in the range of 1 to 30. Longer R1 chains exhibit a stronger inhibitory effect on the electroplated metal and a better leveling effect in higher density distribution regions. Therefore, in embodiments of the present application, different R1 chain lengths may be selected based on the distribution density in the application scenario.

[0013] In an embodiment of the present application, x is equal to 0, L represents a single bond, and R5 is ethylidene. In this case, R1 is -(CH2CH2O) y -CH2CH2-. In an embodiment of the present application, x is equal to 0, L represents a single bond, and R5 is isopropylidene. In this case, R1 is -(CH2CHCH2O) y -CH2CHCH2-. In an embodiment of the present application, x is an integer of 1 or greater, L represents a single bond, R4 is ethylidene, and R5 is isopropylidene. In this case, R1 is -(CH2CH2O) x -(CH2CHCH2O) y -CH2CHCH2-. In the foregoing embodiments, L represents a single bond. In some embodiments of the present application, L may alternatively be at least one ether oxygen block. For example, in some embodiments, L is one ether oxygen block-(R6O) k -. In some embodiments, L is two ether oxygen blocks-(R6O) k -(R7O) l -, and k and l are integers of 1 or greater.

[0014] In an embodiment of the present application, for R3, the linking group comprising an ether oxygen atom, an ester group and / or an imide group may specifically be alkylene comprising an ether oxygen atom, an ester group and / or an imide group, arylene comprising an ether oxygen atom, an ester group and / or an imide group, arylenealkyl comprising an ether oxygen atom, an ester group and / or an imide group, or alkylenearyl comprising an ether oxygen atom, an ester group and / or an imide group.

[0015] In a second aspect of an embodiment of the present application, a method for preparing a leveling agent is provided. The method comprises: reacting, at a first temperature, a compound having hydroxyl groups at both ends represented by formula (a) with a compound having an acyl halide group represented by formula (b) to obtain an intermediate; Next, a step of reacting the intermediate with a compound having a bipyridine structure represented by formula (c) at a second temperature to obtain a leveling agent, having

[0016]

Chemical Formula

[0017]

Chemical Formula

[0018]

Chemical Formula

[0019]

Chemical Formula

[0020] In formula (I), R1 and R2 are independently one of the following: a substituted or unsubstituted alkylene, a substituted or unsubstituted arylene, a substituted or unsubstituted arylenealkyl, a substituted or unsubstituted alkylenearyl, an alkylene containing an ether oxygen atom, an ester, and / or imide, an arylene containing an ether oxygen atom, an ester, and / or imide, an arylenealkyl, and an alkylenearyl containing an ether oxygen atom, an ester, and / or imide. R3 is one of the following: a single bond, a substituted or unsubstituted alkylene, a substituted or unsubstituted arylene, a substituted or unsubstituted arylenealkyl, a substituted or unsubstituted alkylenearyl, and a bonding group containing an ether oxygen atom, an ester, and / or imide.

[0021] From the reaction process described above, it can be seen that R1 in equation (a) is the same as R1 in equation (I), R2 in equation (b) is the same as R2 in equation (I), and R3 in equation (c) is the same as R3 in equation (I). Further details will not be explained again here.

[0022] In the embodiments of the present application, the first temperature is in the range of -20°C to 25°C.

[0023] In the embodiments of the present application, the second temperature is in the range of 25°C to 200°C.

[0024] In some embodiments of the present application, the compound having hydroxyl groups at both ends represented by formula (a) may have the structure represented by formula (a-1), formula (a-2), or formula (a-3), where m and n in formula (a-1), formula (a-2), or formula (a-3) are integers of 1 or more.

[0025] [ka] Formula (a-1)

[0026] [ka] Formula (a-2)

[0027] [ka] Formula (a-3) The method for preparing the leveling agent in this embodiment of the present application requires a simple process and is suitable for large-scale production.

[0028] In a third embodiment of the present invention, a composition is provided, which is an electroplating composition comprising a metal ion source and a leveling agent, wherein the leveling agent is a leveling agent according to the first embodiment of the present invention or a leveling agent obtained using a preparation method according to the second embodiment of the present invention.

[0029] In the embodiments of this application, the concentration of the leveling agent in the electroplating composition is in the range of 1 ppm to 100 ppm. The concentration of the leveling agent in the electroplating composition is controlled within a suitable range, which facilitates obtaining a moderate metal deposition rate and enables better defect-free, highly flat filling of small holes or grooves across the entire substrate, thereby facilitating the manufacture of fine wiring and improving the reliability of electronic products.

[0030] In embodiments of the present application, the electroplating composition further comprises one or more accelerators, inhibitors, or inorganic additives. The leveling agent works in cooperation with accelerators, inhibitors, etc. to significantly reduce the surface roughness of the copper layer. In areas with different distribution densities, the thickness of the surface copper can also be made uniform, and defect-free, highly flat filling of small-sized grooves can be performed across the entire substrate, thereby reducing the technical difficulties of subsequent polishing processes.

[0031] In embodiments of the present application, the accelerator comprises one or more of 3-mercapto-1-propanesulfonate sodium (MPS), polydithiodipropanesulfonate sodium (SPS), or N,N-dimethyldithiocarboxamidepropanesulfonate sodium (DPS), and the concentration of the accelerator in the electroplating composition is in the range of 1 ppm to 50 ppm. The addition of the accelerator promotes the deposition of metal at the bottom of the grooves and refines the grain of the metal layer.

[0032] In embodiments of the present application, the inhibitor comprises one or more of polyethylene glycol (PEG), polypropylene glycol (PPG), block copolymer PEO-PPO-PEO, block copolymer PPO-PEO-PPO, random copolymer of EO and PO, or propylene glycol block polyether, and the concentration of the inhibitor in the electroplating composition is in the range of 1 ppm to 2000 ppm. The addition of the inhibitor inhibits the rapid deposition of surface copper, prevents premature sealing of pores or grooves, and facilitates obtaining a thin surface copper after copper plating.

[0033] In this embodiment of the application, the inorganic additive contains chloride ions, and the concentration of chloride ions in the electroplating composition is in the range of 1 ppm to 100 ppm. The addition of chloride ions suppresses densification, refinement, and coarsening of the crystals in the plating layer.

[0034] In embodiments of the present application, the electroplating composition further comprises at least one acid, the at least one acid comprising sulfuric acid and / or methyl sulfonate.

[0035] In embodiments of the present application, the concentration of at least one acid in the electroplating composition is in the range of 1 g / L to 100 g / L. A suitable acid system and acid concentration contribute to obtaining a suitable electroplating rate.

[0036] In the embodiments of the present application, the metal ion source includes one of the following: a copper ion source, a nickel ion source, a tin ion source, a cobalt ion source, a ruthenium ion source, or a silver ion source. When a certain type of metal layer is pre-deposited, it is understood that the metal ion source in the electroplating composition includes corresponding metal ion sources corresponding to the metal elements in the pre-deposited metal layer.

[0037] In this embodiment of the application, the copper ion source comprises copper sulfate pentahydrate and / or copper methylsulfonate, and the concentration of the copper ion source in the electroplating composition is in the range of 1 g / L to 100 g / L with respect to copper ions. Controlling the copper ion source within a suitable range helps to balance the deposition rate, brightness, and flatness of the resulting copper plating layer.

[0038] A fourth embodiment of the present invention provides the application of a leveling agent obtained using the leveling agent according to the first embodiment or the preparation method according to the second embodiment, or the application of a composition according to the third embodiment in metal electroplating.

[0039] In the embodiments of the present invention, the electroplated metal includes one of the following: copper and copper alloys, nickel and nickel alloys, tin and tin alloys, cobalt and cobalt alloys, ruthenium and ruthenium alloys, or silver and silver alloys.

[0040] In embodiments of the present application, the electroplated metal includes all electroplated metals used to fill holes or grooves in an electronic substrate. The electronic substrate may be a common substrate, a printed circuit board, a package substrate, etc. The holes or grooves include grooves and / or through-holes, and the through-holes may include plated through-holes, blind via holes, and buried via holes.

[0041] In embodiments of the present application, the electroplated metal includes electroplating of metal in a printed circuit board preparation process, electroplating of metal in an integrated circuit metal interconnection process, or electroplating of metal in an electronic packaging process. In particular, the electroplated metal may be an electroplated metal in processes such as Damascus groove filling, silicon plated through-hole filling, substrate redistribution, metal bump deposition, or hole or groove filling.

[0042] The leveling agent provided in the embodiments of this application is used in all metal electroplating for filling holes or grooves in electronic substrates, enabling defect-free filling of nanoscale small holes or grooves, reducing the thickness difference between high-density and low-density interconnect pattern areas in the copper interconnect layer, resulting in a flatter and more uniform surface of the plated layer, improving the uniformity of electroplating across the entire electronic substrate, and simplifying the subsequent CMP process. Furthermore, it facilitates the manufacture of fine wiring, improves the reliability of electronic products, and more favorably satisfies the manufacturing requirements for high-density interconnect products with a simple process and low cost.

[0043] A fifth embodiment of the present invention provides a metal electroplating method, the method being: The method includes the steps of bringing a substrate to be electroplated into contact with a composition according to a third embodiment of the present invention, and applying an electric current to the substrate to be electroplated to perform electroplating and form a metal layer on the substrate.

[0044] In the embodiments of the present invention, the electroplating process conditions are such that the electroplating temperature is in the range of 10°C to 40°C, the current density is in the range of 0.5ASD to 6ASD, and the electroplating time is in the range of 10 to 200 seconds.

[0045] In the embodiments of the present application, electroplating includes a first electroplating step, a second electroplating step, and a third electroplating step, wherein in the first electroplating step, the current density is in the range of 0.2 ASD to 1 ASD and the electroplating time is in the range of 1 s to 15 s; in the second electroplating step, the current density is in the range of 0.8 ASD to 2 ASD and the electroplating time is in the range of 10 s to 100 s; and in the third electroplating step, the current density is in the range of 2 ASD to 6 ASD and the electroplating time is in the range of 10 s to 100 s.

[0046] In embodiments of the present application, the holes or grooves are provided on the electroplated substrate, and the metal layer includes an in-hole filling layer that fills the holes or grooves and a surface deposit layer deposited around the holes or grooves.

[0047] A sixth aspect of the present application provides an electronic circuit board including a base layer and a metal layer disposed on the base layer, wherein the metal layer is formed by electroplating a composition according to a third aspect of the present application or by a method according to a fifth aspect.

[0048] In the embodiments of the present application, the metal layer includes one of the following: a copper or copper alloy layer, a nickel or nickel alloy layer, a tin or tin alloy layer, a cobalt or cobalt alloy layer, a ruthenium or ruthenium alloy layer, and a silver or silver alloy layer.

[0049] In embodiments of the present application, an electronic device is further provided that includes an electronic substrate according to a sixth embodiment of the present application. [Brief explanation of the drawing]

[0050] [Figure 1a] This diagram shows a void defect formed by filling holes or grooves with electroplated copper. [Figure 1b] This diagram shows a seam defect formed by filling holes or grooves with electroplated copper. [Figure 1c]This diagram shows a superfill formed by filling holes or grooves with electroplated copper. [Figure 2] This figure illustrates the formation of a non-flat copper layer by filling holes or grooves with electroplated copper using conventional technology. [Figure 3] This is a diagram illustrating the process of forming a copper interconnect layer in a semiconductor process. [Figure 4] This is a diagram of the structure of a substrate having multiple copper interconnection layers. [Figure 5] This is a diagram showing the structure of an electronic circuit board 100 according to one embodiment of the present invention. [Figure 6a] This is a cross-sectional electron microscope image of an electroplated sample used as a comparative example. [Figure 6b] This is a partially enlarged view of Figure 6a. [Figure 7] This is a cross-sectional electron microscope image of a sample after electroplating according to Embodiment 1 of the present invention. [Figure 8] This is a cross-sectional electron microscope image of a sample after electroplating according to Embodiment 2 of the present invention. [Figure 9] This is a cross-sectional electron microscope image of a sample after electroplating according to Embodiment 2 of the present invention. [Modes for carrying out the invention]

[0051] Hereinafter, embodiments of the present invention will be described with reference to the attached drawings of the embodiments of the present invention.

[0052] Figure 3 shows the process of forming a copper interconnect layer in a semiconductor process. In Figure 3, 10a is a patterned substrate, which includes a substrate 11 and a patterned dielectric layer 21, and the patterned dielectric layer 21 has a plurality of grooves 2. After electroplating and copper film deposition on the patterned substrate 10a, the plurality of grooves 2 in the dielectric layer 21 are filled with copper, forming a copper layer 22, and an electroplated substrate 10b is obtained. The copper layer 22 includes a pore-filling layer that is filled in the grooves 2 and a surface deposition layer that covers the surface of the dielectric layer 21. In the electroplated substrate 10b, the dielectric layer 21 and the copper layer 22 together form a copper interconnect layer 20' that is not processed in the CMP process. After removing the surface deposition layer of the copper layer 22 from the electroplated substrate 10b via the CMP process, a copper interconnect layer 20 processed by the CMP process, i.e., a substrate 10c processed by the CMP process, is obtained. As shown in Figure 4, in actual specifications, the substrate 10c processed by the CMP process may be further prepared using copper interconnect layers. For example, a copper interconnect layer 30 may be formed on the copper interconnect layer 20 to obtain a substrate 10d having multiple copper interconnect layers. To improve the reliability of the copper interconnect layer 20, it is ideal that the pore-filling layer in the grooves 2 is free from defects such as voids or seams, as shown in Figure 3. An ideal case in the electroplating and copper deposition process to facilitate the implementation of the CMP process is that the copper layer 22 is shown on the electroplated substrate 10b in Figure 3. The difference in thickness between the copper interconnect layer in the high-density interconnect pattern region and the copper interconnect layer in the low-density interconnect pattern region is small, the overall surface of the copper layer 22 is relatively flat, and the overall thickness of the copper layer 22 is relatively small. However, it is difficult to form a defect-free copper interconnect layer with high surface flatness using current electroplating solution chemicals. Defects such as voids or seams, as shown in Figures 1(a) and 1(b), tend to occur, or the thickness of the copper interconnect layer in the high-density interconnect pattern region tends to deviate significantly from the thickness of the copper interconnect layer in the low-density interconnect pattern region, as shown in Figure 2.A high-density interconnection pattern region is a region in the interconnection layer that has a relatively high density of interconnection patterns (e.g., holes or grooves) (including a certain amount of holes or grooves, or the area of ​​a portion of all holes or grooves). A low-density interconnection pattern region is a region in the interconnection layer that has a relatively low density of interconnection patterns (e.g., holes or grooves).

[0053] Furthermore, as semiconductor process precision improves, device feature sizes decrease, and distribution designs become increasingly complex, making it increasingly difficult to obtain defect-free, highly planar copper interconnect layers. Consequently, the requirements for the chemicals in the electroplating solutions used to fill small-sized grooves are becoming more stringent. In one embodiment of the present invention, a leveling agent is provided to achieve defect-free filling of small-sized grooves by reducing the thickness difference between high-density and low-density interconnect pattern regions in the copper interconnect layer, making the surface of the plated layer flatter and more uniform, simplifying the subsequent CMP process, and achieving defect-free filling with high surface flatness. The leveling agent can suppress metal deposition to some extent, and as a result, defect-free, highly planar filling can be achieved for small-sized holes or grooves (including grooves and through-holes).

[0054] The leveling agent provided in this embodiment of the present application may be added to an electroplating solution as an additive for metal electroplating, wherein the leveling agent is a polypyridine compound, and the polypyridine compound includes a structural unit shown in formula (I), or a protonated product of the structural unit shown in formula (I).

[0055] [ka] Equation (I) In formula (I), R1 and R2 are independently any one of the following: a substituted or unsubstituted alkylene, a substituted or unsubstituted arylene, a substituted or unsubstituted arylenealkyl, a substituted or unsubstituted alkylenearyl, an alkylene containing an ether oxygen atom, an ester, and / or imide, an arylene containing an ether oxygen atom, an ester, and / or imide, an arylenealkyl, an ether oxygen atom, an ester, and / or imide, and an alkylenearyl containing an ether oxygen atom, an ester, and / or imide. R3 is any one of the following linking groups: a single bond, a substituted or unsubstituted alkylene, a substituted or unsubstituted arylene, a substituted or unsubstituted arylenealkyl, a substituted or unsubstituted alkylenearyl, and an ether oxygen atom, an ester, and / or imide.

[0056] The leveling agent in this embodiment of the present application is, in particular, a polypyridine compound containing an ester. The leveling agent has a relatively good leveling effect. The leveling agent is added to an electroplating composition and used in semiconductor manufacturing processes to fill holes or grooves with metal electroplating, preventing to some extent the excess deposition of metal. In this way, defect-free metal filling of holes or grooves is achieved, relatively small holes or grooves are not completely filled in advance, the thickness difference between electroplated metal layers in distribution regions with different densities is reduced, the waviness of the platform on the surface of the plating layer is greatly suppressed, and a better planarization effect can be obtained. This facilitates the subsequent CMP process. The polymer in the leveling agent in this embodiment of the present application has a stable molecular structure, and therefore the impurity content in the resulting plating layer is low, improving the reliability of the plating layer.

[0057] In embodiments of the present application, the polypyridine compound comprises a protonation product of the structural unit shown in formula (I) and a halide ion, i.e., the polypyridine compound comprises a structural unit shown in formula (II), and the halide ion comprises one of the following: a fluoride ion, a chloride ion, a bromide ion, and an iodide ion. The protonation product of the structural unit shown in formula (I) may be represented as formula (I-1). It can be understood that each substituent in formula (I-1) and formula (II) corresponds to the corresponding substituent in formula (I). In formula (II), X - is a halide ion. In some embodiments, two X of formula (I) - These are the same halide ions, which facilitates the preparation of leveling agents.

[0058] [ka] Equation (I-1)

[0059] [ka] Formula (II) In the embodiments of the present application, the amount of carbon atoms in the substituted or unsubstituted alkylene in R1, R2, and R3 may be in the range of 1 to 30. In some embodiments, the amount of carbon atoms in the substituted or unsubstituted alkylene may specifically be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30. Specifically, R1, R2, and R3 may be, for example, substituted or unsubstituted methylene, substituted or unsubstituted ethylidene, substituted or unsubstituted propylidene, substituted or unsubstituted isopropylidene, substituted or unsubstituted butylidene, substituted or unsubstituted isobutylidene, substituted or unsubstituted neopentylene, or substituted or unsubstituted hexylidene.

[0060] In the embodiments of this application, the amount of carbon atoms in the substituted or unsubstituted arylene in R1, R2, and R3 may be in the range of 6 to 30. In some embodiments, the amount of carbon atoms in the substituted or unsubstituted arylene may specifically be 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30. Specifically, R1, R2, and R3 may be, for example, substituted or unsubstituted benzene, substituted or unsubstituted biphenylene, substituted or unsubstituted terphenyl, substituted or unsubstituted fluorenylidene, substituted or unsubstituted naphthalene, or substituted or unsubstituted anthracene.

[0061] In the embodiments of this application, the number of carbon atoms in the substituted or unsubstituted arylenealkyl in R1, R2, and R3 may be in the range of 7 to 40. In some embodiments, the number of carbon atoms in the substituted or unsubstituted arylenealkyl may specifically be 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40. In the embodiments of this application, the number of carbon atoms in the substituted or unsubstituted alkylenearyl in R1, R2, and R3 may be in the range of 7 to 40. In some embodiments, the number of carbon atoms in the substituted or unsubstituted alkylenearyl may be specifically 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40.

[0062] In the embodiments of this application, the substituents in R1, R2, and R3 in the substituted alkylene, substituted arylene, substituted arylenealkyl, and substituted alkylenearyl are not particularly limited, but may be halide atoms.

[0063] In the embodiments of the present application, the amount of carbon atoms in the alkylene containing ether oxygen atoms, esters, and / or imides in R1 may be in the range of 2 to 30, and the amount of carbon atoms is specifically, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30. The amount of carbon atoms in the arylene containing ether oxygen atoms, esters, and / or imides may be in the range of 6 to 30, and the amount of carbon atoms is specifically, for example, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 28, 29, or 30. The amount of carbon atoms in an arylenealkyl containing an ether oxygen atom, an ester, and / or imide is in the range of 7 to 40, specifically the amount of carbon atoms being, for example, 7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40. The amount of carbon atoms in an alkylenearyl containing ether oxygen atoms, esters, and / or imides may be in the range of 7 to 40, specifically, the amount of carbon atoms may be, for example, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40.Alkylenes containing an ether oxygen atom, an ester, and / or imide are alkylenes containing one or more ether oxygen atoms, esters, or imides: Arylenes containing an ether oxygen atom, an ester, or imide are arylenes containing one or more ether oxygen atoms, esters, and / or imides: Arylene alkyls containing an ether oxygen atom, an ester, and / or imide are arylene alkyls containing one or more ether oxygen atoms, esters, and / or imides: Alkylene aryls containing an ether oxygen atom, an ester, and / or imide are alkylene aryls containing one or more ether oxygen atoms, esters, and / or imides.

[0064] In some embodiments of the present application, R1 may be an alkylene containing one or more ether oxygen atoms, an arylene having one or more ether oxygen atoms, an arylene alkyl having one or more ether oxygen atoms, or an alkylene aryl having one or more ether oxygen atoms. R1 is a group containing ether oxygen atoms, which better suppresses excess deposition of metal, reduces the thickness difference between electroplated metal layers in distribution regions having different densities, and provides a better flatness effect.

[0065] In some embodiments of the present application, R1 may be an alkylene containing an ether oxygen atom, and the alkylene containing an ether oxygen atom is -(R4O) x -L-(R5O) yIt may also be represented as -R5-, where R4 and R5 may be the same or different alkylenes, x is a non-negative integer, y is a non-negative integer, and L represents a single bond or at least one ether oxygen block. R4 and R5 may be alkylenes having 2 to 10 carbon atoms in particular, for example, ethylidene, propylidene, or isopropylidene. The values ​​of x and y may be in the range of 1 to 300. In some embodiments, the values ​​of x and y may be in the range of 1 to 100. In some embodiments, the values ​​of x and y may be in the range of 1 to 30. In some embodiments, the values ​​of x and y may be in particular 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30. Longer R1 chains exhibit a stronger inhibitory effect on the electroplating metal and better leveling in higher density distribution regions. Therefore, in this embodiment of the present application, different R1 chain lengths may be selected based on the distribution density in the application scenario.

[0066] In the embodiments of this application, x is equal to 0, L represents a single bond, R5 is ethylidene, and in this case R1 is -(CH2CH2O) y It is represented as -CH2CH2-. In the embodiments of this application, x is equal to 0, L represents a single bond, R5 is isopropylidene, and in this case R1 is -(CH2CHCH2O) y It is represented as -CH2CHCH2-. In the embodiments of this application, x is an integer greater than or equal to 1, L represents a single bond, R4 is ethylidene, and R5 is isopropylidene. In this case, R1 is -(CH2CH2O) x -(CH2CHCH2O) y It is represented as -CH2CHCH2-. In the embodiments described above, L represents a single bond. Alternatively, in some embodiments of the present application, L may be at least one ether oxygen block. For example, in some embodiments, L may be one ether oxygen block -(R6O) k-In some embodiments, L is two ether oxygen blocks - (R6O) k -(R7O) l - and k and l are integers greater than or equal to 1.

[0067] In the embodiments of this application, the bonding group in R3 containing an ether oxygen atom, an ester, and / or imide may be, in particular, an alkylene containing an ether oxygen atom, an ester, and / or imide, an arylene containing an ether oxygen atom, an ester, and / or imide, an arylenealkyl containing an ether oxygen atom, an ester, and / or imide, or an alkylenearyl containing an ether oxygen atom, an ester, and / or imide. The selection of the aforementioned chemical groups is the same as for R1 and R2, and the details will not be described again here. In some embodiments, the bonding group containing an imide may be -HN-C(=O)-RC(=O)-NH-, and R may be a substituted or unsubstituted alkylene.

[0068] In some embodiments of the present application, the polypyridine compound comprises only the protonation product and halide ion of the structural unit shown in formula (I), and the polypyridine compound is represented as the polypyridine salt compound shown in formula (1):

[0069] [ka] Formula (1) Here, in equation (1), n ​​is an integer greater than or equal to 2. In some embodiments, n may be an integer in the range of, for example, 2 to 15. Specifically, n may be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15.

[0070] In response to this, one embodiment of the present application further provides a method for preparing a leveling agent, the method comprising steps S101 and S102: Step S101: At a first temperature, a compound having hydroxyl groups at both ends, represented by formula (a), is reacted with a compound containing an acyl halide group, represented by formula (b), to obtain an intermediate. Step S102: At a second temperature, the intermediate is reacted with a compound having a bipyridine structure represented by formula (c) to obtain a leveling agent. Here, the leveling agent includes a polypyridine compound, the polypyridine compound being a protonated product of the structural unit shown in formula (I), or the structural unit shown in formula (I).

[0071] [ka] Formula (a)

[0072] [ka] Formula (b)

[0073] [ka] Formula (c)

[0074] [ka] Equation (I) In formula (a), R1 is any one of substituted or unsubstituted alkylenes, substituted or unsubstituted arylenes, substituted or unsubstituted arylenealkyls, substituted or unsubstituted alkylenearyls, alkylenes containing an ether oxygen atom, an ester and / or imide, arylenes containing an ether oxygen atom, an ester and / or imide, arylenealkyls containing an ether oxygen atom, an ester and / or imide, and alkylenearyls containing an ether oxygen atom, an ester and / or imide, and in formula (b), X1 and X are R2 is any one of the following: substituted or unsubstituted alkylene, substituted or unsubstituted arylene, substituted or unsubstituted arylenealkyl, substituted or unsubstituted alkylene, substituted or unsubstituted alkylenearyl, alkylene containing an ether oxygen atom, ester, and / or imide, arylene containing an ether oxygen atom, ester, and / or imide, and alkylenearyl containing an ether oxygen atom, ester, and / or imide. In formula (c), R3 is any one of the following bonding groups: single bond, substituted or unsubstituted alkylene, substituted or unsubstituted arylene, substituted or unsubstituted arylenealkyl, substituted or unsubstituted alkylenearyl, and bonding group containing an ether oxygen atom, ester, and / or imide.

[0075] In formula (I), R1 and R2 are independently any one of the following: substituted or unsubstituted alkylene, substituted or unsubstituted arylene, substituted or unsubstituted arylenealkyl, substituted or unsubstituted alkylene, substituted or unsubstituted alkylenearyl, alkylene containing an ether oxygen atom, an ester, and / or imide, arylene containing an ether oxygen atom, an ester, and / or imide, and alkylenearyl containing an ether oxygen atom, an ester, and / or imide. R3 is a bond group containing a single bond, substituted or unsubstituted alkylene, substituted or unsubstituted arylene, substituted or unsubstituted alkylene, substituted or unsubstituted alkylene, substituted or unsubstituted alkylenearyl, and an ether oxygen atom, an ester, and / or imide.

[0076] From the reaction process described above, it can be seen that R1 in equation (a) is the same as R1 in equation (I), R2 in equation (b) is the same as R2 in equation (I), and R3 in equation (c) is the same as R3 in equation (I). Further details will not be explained again here.

[0077] In some embodiments of the present application, the polypyridine compound comprises a structural unit represented by formula (II), where X - It is a halide ion.

[0078] [ka] Formula (II) X in equation (II) - This originates from the halide atom X in formula (b).

[0079] In some embodiments of the present application, the compound having hydroxyl groups at both ends represented by formula (a) may have the structure represented by formula (a-1), formula (a-2), or formula (a-3), where m and n are integers of 1 or more, for example, in the range of 1 to 300. In some embodiments, the values ​​of m and n may be specifically 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30.

[0080] [ka] Formula (a-1)

[0081] [ka] Formula (a-2)

[0082] [ka] Formula (a-3) In the embodiments of this application, the first temperature in step S101 may be in the range of -20°C to 25°C. In some embodiments, the first temperature may be in the range of 0°C to 10°C. In the reaction process of step S101, dichloromethane or the like may be used as the solvent.

[0083] In the embodiments of the present application, the second temperature in step S102 may be in the range of 25°C to 200°C. In some embodiments, the second temperature may be in the range of 50°C to 150°C.

[0084] In this embodiment of the present application, the polypyridine compound prepared is a solid.

[0085] One embodiment of the present application further provides an electroplating composition, which in this embodiment comprises a metal ion source and the leveling agent described above. The electroplating composition may be used as an electroplating solution for electroplating and depositing a metal layer.

[0086] In the embodiments of this application, the concentration of the leveling agent in the electroplating composition is in the range of 1 ppm to 100 ppm. In some embodiments, the concentration of the leveling agent is in the range of 2 ppm to 80 ppm. In some embodiments, the concentration of the leveling agent is in the range of 5 ppm to 50 ppm. In some embodiments, the concentration of the leveling agent is in the range of 10 ppm to 30 ppm. In particular, in some embodiments, the concentration of the leveling agent may be 1 ppm, 2 ppm, 5 ppm, 8 ppm, 10 ppm, 12 ppm, 15 ppm, 18 ppm, 20 ppm, 25 ppm, 30 ppm, 40 ppm, or 50 ppm. The concentration of the leveling agent in the electroplating composition is controlled within a suitable range to facilitate obtaining a moderate metal deposition rate, resulting in better defect-free, high-flatness filling of small holes or grooves across the entire substrate, thereby facilitating the manufacture of fine wiring and improving the reliability of electronic products.

[0087] In the embodiments of this application, the electroplating composition further comprises one or more of an accelerator, inhibitor, or inorganic additive. The leveling agent works in cooperation with the accelerator, inhibitor, etc. to significantly reduce the surface roughness of the copper layer. It can also make the thickness of the surface copper uniform in areas with different distribution densities, and as a result, small-sized holes or grooves throughout the substrate can be filled with defect-free, highly flat surfaces, thereby reducing the technical difficulties of the subsequent polishing process.

[0088] In the embodiments of this application, the accelerator comprises one or more of sodium 3-mercapto-1-propanesulfonic acid (MPS), sodium polydithiodipropanesulfonic acid (SPS), or sodium N,N-dimethyldithiocarboxamidepropanesulfonate (DPS). The addition of the accelerator promotes the deposition of metal at the bottom of the groove and refines the crystal grains of the metal layer. In the embodiments of this application, the concentration of the accelerator in the electroplating composition may be in the range of 1 ppm to 50 ppm. In some embodiments, the concentration of the accelerator in the electroplating composition may be in the range of 2 ppm to 40 ppm. In some embodiments, the concentration of the accelerator in the electroplating composition may be in the range of 5 ppm to 35 ppm. In some embodiments, the concentration of the accelerator in the electroplating composition may be in the range of 10 ppm to 30 ppm.

[0089] In the embodiments of this application, the inhibitor comprises one or more of polyethylene glycol (PEG), polypropylene glycol (PPG), block copolymer PEO-PPO-PEO (polyethylene oxide-polypropylene oxide-polyethylene oxide), block copolymer PPO-PEO-PPO (polypropylene oxide-polyethylene oxide-polypropylene oxide), random copolymers of polyoxyethylene (EO) and polyoxypropylene (PO), or propylene glycol block polyether. The addition of the inhibitor can inhibit the rapid deposition of surface copper, prevent premature sealing of pores or grooves, and facilitate the acquisition of a thin surface copper after copper plating. In embodiments of this application, the concentration of the inhibitor in the electroplating composition may range from 1 ppm to 2000 ppm. In some embodiments, the concentration of the inhibitor in the electroplating composition is in the range of 10 ppm to 1000 ppm. In some embodiments, the concentration of the inhibitor in the electroplating composition is in the range of 100 ppm to 1000 ppm. In some examples, the inhibitor concentration in the electroplating composition is in the range of 150 ppm to 500 ppm. In examples of this application, the inorganic additive contains chloride ions, and the chloride ion concentration in the electroplating composition is in the range of 1 ppm to 100 ppm. In some examples, the chloride ion concentration in the electroplating composition may be 1 ppm, 5 ppm, 10 ppm, 20 ppm, 30 ppm, 40 ppm, 50 ppm, 60 ppm, 70 ppm, 80 ppm, 90 ppm, or 100 ppm. The addition of chloride ions enables the crystallization of a dense, fine, and smooth plating layer.

[0090] In the embodiments of this application, the electroplating composition further comprises at least one acid, the at least one acid comprising sulfuric acid and / or methyl sulfonate. In the embodiments of this application, the concentration of the at least one acid in the electroplating composition is in the range of 1 g / L to 100 g / L. In some embodiments, the concentration of the at least one acid in the electroplating composition may specifically be, for example, 1 g / L, 10 g / L, 20 g / L, 30 g / L, 40 g / L, 50 g / L, 55 g / L, 60 g / L, 70 g / L, 80 g / L, 90 g / L, or 100 g / L. A suitable acid system and acid concentration are facilitated in obtaining a suitable electroplating rate.

[0091] In embodiments of the present application, the metal ion source includes one of the following: a copper ion source, a nickel ion source, a tin ion source, a cobalt ion source, a ruthenium ion source, or a silver ion source. If a certain type of metal layer is pre-deposited, it can be understood that, correspondingly, the metal ion source in the electroplated composition includes a metal ion source corresponding to the metal element in the pre-deposited metal layer. For example, if a metallic copper layer is pre-deposited, the metal ion source includes a copper ion source.

[0092] In the embodiments of this application, the copper ion source comprises copper sulfate pentahydrate and / or copper methylsulfonate. When electroplating is performed using an acid system of copper ion source, current efficiency is increased, it is environmentally friendly, and the cooperation between various additives allows for better filling of blind via holes. In the embodiments of this application, the concentration of the copper ion source in the electroplating composition is in the range of 1 g / L to 100 g / L with respect to copper icons. In some embodiments, the concentration of the copper ion source in the electroplating composition may be specifically 1 g / L, 10 g / L, 20 g / L, 30 g / L, 40 g / L, 50 g / L, 60 g / L, 70 g / L, 80 g / L, 90 g / L, or 100 g / L with respect to copper icons. Controlling the copper ion source within a suitable range promotes a balance between the deposition rate, brightness, and flatness of the resulting copper plating layer.

[0093] The novel leveling agent provided in this embodiment of the present invention is applied to a metal electroplating solution such as a copper electroplating solution, and in the process of filling holes or grooves, it is possible to obtain a sample with a uniform surface copper thickness and a good appearance of the substrate surface. Therefore, the leveling agent is suitable for precision machining. Furthermore, the operating window of the leveling agent in this embodiment of the present application is wide. For holes or grooves with sizes ranging from 28 nm to 1.2 μm, holes or grooves of all sizes can be filled seamlessly, thereby improving the reliability of the final product.

[0094] In one embodiment of the present application, the application of leveling agents and / or electroplating compositions in a metal electroplating process is further provided. In this application, the electroplated metal may be any one of the following: electroplated copper and copper alloys, electroplated nickel and nickel alloys, electroplated tin and tin alloys, electroplated cobalt and cobalt alloys, electroplated ruthenium and ruthenium alloys, or electroplated silver and silver alloys.

[0095] In embodiments of the present application, the electroplated metal includes electroplating of metals in a printed circuit board preparation process, electroplating of metals in an integrated circuit metal interconnection process, or electroplating of metals in an electronic packaging process. Specifically, the electroplated metal may be a plating metal in processes such as Damascus groove filling, silicon plated through-hole filling, substrate redistribution, metal bump deposition, or through-hole filling.

[0096] In the embodiments of the present application, the electroplated metal includes all electroplated metals used to fill holes or grooves on an electronic substrate. The electronic substrate may be a common substrate, a printed circuit board, a package substrate, etc. The holes or grooves include grooves and / or through-holes, and the through-holes may include plated through-holes, blind via holes, and buried via holes. All metal fillers may be electroplated copper and copper alloys, electroplated nickel and nickel alloys, electroplated tin and tin alloys, electroplated cobalt and cobalt alloys, electroplated ruthenium and ruthenium alloys, or electroplated silver and silver alloys.

[0097] The leveling agent provided in the embodiments of this application is used in all metal electroplating for filling holes or grooves on electronic substrates, enabling defect-free filling of nanoscale holes or grooves, reducing the thickness difference between high-density and low-density interconnect pattern areas in the copper interconnect layer. As a result, the surface of the plated layer becomes flatter and more uniform, improving the uniformity of electroplating across the entire electronic substrate and simplifying the subsequent CMP process. Furthermore, it facilitates the manufacturing of fine wiring, improves the reliability of electronic products, and better meets the manufacturing requirements of high-density interconnect products with a low-cost and simple process.

[0098] In one embodiment of the present invention, a metal electroplating method is provided, further comprising the following steps: In the embodiment of the present invention, the substrate to be electroplated is brought into contact with the aforementioned electroplating composition, an electric current is applied to the substrate to be electroplated, electroplating is performed, and a metal layer is formed on the substrate to be electroplated.

[0099] In particular, the substrate to be electroplated is immersed in the electroplating composition as the cathode, and the electroplating composition, i.e., the electroplating solution, is used as the electrolyte. A conductive loop is formed together with a soluble or insoluble anode, thereby carrying out metal deposition on the substrate to be electroplated.

[0100] In embodiments of the present application, the holes or grooves are provided on the electroplated substrate, and the metal layer includes an in-hole filling layer that fills the holes or grooves and a surface deposit layer deposited around the holes or grooves. The holes or grooves include grooves and / or through-holes, and the through-holes may include one or more plated through-holes, blind via holes, or buried via holes.

[0101] In the embodiments of this application, the horizontal size of the holes or grooves is 28 nm to 1.2 μm, and their depth is 100 nm to 300 nm. Specifically, the horizontal size of the holes or grooves may be, for example, 28 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1.0 μm, 1.1 μm, or 1.2 μm. The depth may be, for example, 100 nm, 200 nm, or 300 nm. Holes or grooves on the substrate to be plated may have different horizontal sizes and different depths. The horizontal size of a groove is the width of the groove, and the horizontal size of a through-hole is the diameter of the through-hole.

[0102] In embodiments of the present invention, regions having different pore or groove distribution densities, such as including high-density pore or groove distribution regions and low-density pore or groove distribution regions, may be arranged on the electroplated substrate.

[0103] Generally, before electroplating is carried out, a metallization process is performed on the inner wall of the hole or groove, in which a metal seed layer, such as a copper seed layer, is chemically plated onto the inner wall of the hole or groove.

[0104] In the embodiments of the present invention, the electroplating process conditions are such that the electroplating temperature is in the range of 10°C to 40°C, the current density is in the range of 0.5ASD to 6ASD, and the electroplating time is in the range of 10 to 200 seconds.

[0105] In the embodiments of the present application, electroplating includes a first electroplating step, a second electroplating step, and a third electroplating step, wherein in the first electroplating step, the current density is in the range of 0.2 ASD to 1 ASD and the electroplating time is in the range of 1 s to 15 s; in the second electroplating step, the current density is in the range of 0.8 ASD to 2 ASD and the electroplating time is in the range of 10 s to 100 s; and in the third electroplating step, the current density is in the range of 2 ASD to 6 ASD and the electroplating time is in the range of 10 s to 100 s. In the embodiments of the present application, step-by-step electroplating allows for better defect-free filling and enables obtaining a suitable thickness of the surface metal layer. Copper electroplating is used as an example. The first electroplating step allows for better restoration of the copper seed layer, the second electroplating step allows for better seam filling, and the third electroplating step thickens the surface to facilitate subsequent polishing and grinding.

[0106] See Figure 5. In one embodiment of the present application, an electronic substrate 100 is provided, further comprising a base layer 101 and a metal layer 102 disposed on the base layer. The metal layer 102 is formed by electroplating using the electroplating composition described in the embodiment of the present application, or by using the metal electroplating method described in the embodiment of the present application.

[0107] In the embodiments of the present application, the metal layer 102 includes one of the following: a copper or copper alloy layer, a nickel or nickel alloy layer, a tin or tin alloy layer, a cobalt or cobalt alloy layer, a ruthenium or ruthenium alloy layer, and a silver or silver alloy layer.

[0108] In embodiments of the present application, the base layer 101 comprises a substrate 1011 and a dielectric layer 1012, the base layer 101 is provided with holes or grooves 103, and the metal layer 102 comprises a pore-filling layer 1021 that fills the holes or grooves 103 and a surface deposit layer 1022 deposited around the holes or grooves 103. In some embodiments, it is understood that after the surface deposit layer 1022 is removed by a CMP process, the metal layer 102 comprises only the pore-filling layer 1021 that fills the holes or grooves 103.

[0109] In the embodiments of this application, a metal seed layer, such as a copper seed layer, formed by metallizing the holes or grooves 103 may be further contained between the base layer 101 and the metal layer 102.

[0110] In the embodiments of this application, the horizontal size of the holes or grooves 103 is in the range of 28 nm to 1.2 μm, and the depth is in the range of 100 nm to 300 nm. Multiple holes or grooves 103 may be provided in the base layer 101, and the multiple holes or grooves 103 may have different horizontal sizes and different depths, or they may have the same horizontal size and the same depth.

[0111] In the embodiments of the present application, the thickness of the surface deposit layer 1022 is less than 8 μm. In the embodiments of the present application, the ratio of the average thickness H1 of the surface deposit layer 1022 in the high-density interconnection pattern region to the average thickness H2 of the surface deposit layer 1022 in the low-density interconnection pattern region is 1.7 or less. In some embodiments, the ratio of H1 to H2 is 1.5 or less. In some embodiments, the ratio of H1 to H2 is 1.3 or less. In some embodiments, the ratio of H1 to H2 is 1.1 or less.

[0112] Figure 5 of this embodiment of the present application is understood to be a diagram of the structure of the electronic substrate 100 that has not been treated by the CMP process. In actual applications, the surface deposit layer 1022 is removed using a polishing process.

[0113] In one embodiment of the present application, an electronic device is further provided which uses the aforementioned electronic circuit board 100 in the embodiment of the present application.

[0114] The embodiments of this application will be further described below using several embodiments.

[0115] Example 1 Polypyridine compound A, represented by the following formula (1):

[0116] [ka] Formula (1) R1 is

[0117] [ka] And R2 is, R2 is,

[0118] [ka] R3 has a single bond, X - is Cl - Here, n is 4, and * represents the bond position.

[0119] The method for preparing polypyridine compound A is as follows: (1) Add 50 mL of dichloromethane, 20 mmol of triethylene glycol, and 40 mmol of triethylamine to a three-necked flask equipped with a thermometer, a mixer, and a constant-pressure dropping funnel, and operate the mixer to control the temperature from 0 to 10°C. (2) Dissolve 40 mmol of 4-chlorobutyryl chloride in dichloromethane, transfer the resulting solution to a constant-pressure dropping funnel, and slowly add it dropwise at a temperature of 0 to 10°C and a rate of 1 mL / min. After the addition is complete, allow the reaction to continue at room temperature for at least 12 hours. Next, volatilize the reaction mixture to remove the dichloromethane, then dissolve the resulting solution with ethyl acetate and water, extract the organic phase of ethyl acetate, wash with water, and then volatilize the resulting solution to obtain the ester intermediate. (3) Add 20 mmol of the obtained ester intermediate and 20 mmol of 4,4'-bipyridine to a round-bottom flask equipped with a mixer, and operate the mixer to raise the temperature to 120°C. After reacting for 12 hours, the temperature is lowered to room temperature to obtain the final polypyridine compound A in solid state.

[0120] The copper electroplating solution contains each component in the following mass ratios: Copper sulfate pentahydrate (copper ion equivalent): 50g / L Sulfuric acid::50g / L Chloride ions: 50 ppm Polypyridine compound A: 10 ppm Accelerator SPS (sodium polydithiodipropanesulfonate): 25 ppm Inhibitor L64 (propylene glycol blocked polyether): 300 ppm.

[0121] To reflect the effect of the leveling agent provided in this embodiment of the present application, a copper electroplating solution without the leveling agent is used as a comparative example. The only difference between the copper electroplating solution in the comparative example and the copper electroplating solution in Example 1 is that polypyridine compound A is not added.

[0122] The copper electroplating solution of Example 1 and the copper electroplating solution of the Comparative Example were used separately to electroplat a substrate having a groove structure with a diameter of 60 nm to 120 nm and a depth of 120 nm to 250 nm, and copper electroplating was performed. Here, the substrate to be electroplated was a patterned substrate having a PVD copper seed layer, the electroplating temperature was room temperature, and a three-stage current method was used for the electroplating process. In the first step, the current density was 0.65 ASD and the electroplating time was 6 seconds, in the second step, the current density was 1 ASD and the electroplating time was 40 seconds, and in the third step, the current density was 6 ASD and the electroplating time was 45 seconds.

[0123] Figures 6a and 6b are cross-sectional electron microscope images of electroplated samples according to a comparative example, with Figure 6b being a magnified view of a portion of Figure 6a. From Figures 6(a) and 6(b), it can be seen that when no leveling agent is added, the copper layer surface in the high-density groove region and the low-density groove region becomes significantly undulated, and the ratio of the average thickness of the copper layer in the high-density groove region to the copper layer in the low-density groove region reaches a maximum of 1.806, making subsequent CMP operations difficult.

[0124] Figure 7 is a cross-sectional electron microscope image of a sample after electroplating according to Embodiment 1 of the present invention. From Figure 7, it can be seen that when a leveling agent of polypyridine compound A is added, the copper layer surface does not undulate much in the high-density groove region and the low-density groove region, and the ratio of the average thickness of the copper layer in the high-density groove region to the average thickness of the copper layer in the low-density groove region is only 1.023, indicating a significant improvement in flatness and a great reduction in the burden of the subsequent CMP polishing process. Furthermore, from Figure 7, it can be seen that an electroplating solution using a leveling agent of polypyridine compound A can achieve defect-free filling of small grooves and simultaneous filling with high flatness, even in the case of different sizes and distribution densities.

[0125] Example 2 Polypyridine compound B shown in formula (1):

[0126] [ka] Formula (1) R1 is

[0127] [ka] And R2 is,

[0128] [ka] And R3 is,

[0129] [ka] X - is Cl - Here, n is 4, and * represents the bond position.

[0130] The method for preparing polypyridine compound B is as follows: (1) Add 50 mL of dichloromethane, 20 mmol of triethylene glycol, and 40 mmol of triethylamine to a three-necked flask equipped with a thermometer, a mixer, and a constant-pressure dropping funnel, and operate the mixer to control the temperature in the range of 0 to 10°C. (2) Dissolve 40 mmol of 4-chlorobutyryl chloride in dichloromethane, transfer the resulting solution to a constant-pressure dropping funnel, and slowly add it dropwise at a temperature of 0 to 10°C and a rate of 1 mL / min. After the addition is complete, allow the reaction to continue at room temperature for at least 12 hours. Next, volatilize the reaction mixture to remove the dichloromethane, then dissolve the resulting solution with ethyl acetate and water to extract the organic phase of ethyl acetate, wash with water, and volatilize the resulting solution to obtain the ester intermediate. (3) Add 20 mmol of the obtained ester intermediate and 20 mmol of the compound containing the bipyridine structure shown in formula (c-1) to a round-bottom flask equipped with a mixer, operate the mixer, raise the temperature to 120°C and react for 12 hours, then lower the temperature to room temperature to obtain the final polypyridine compound B in solid state.

[0131] [ka] Formula (c-1) The copper electroplating solution contains each component in the following mass ratios: Copper sulfate pentahydrate (copper ion equivalent): 50g / L Sulfuric acid: 50g / L Chloride ions: 50 ppm Polypyridine compound A: 10 ppm Accelerator SPS (sodium polydithiodipropanesulfonate): 25 ppm Inhibitor L65 (propylene glycol blocked polyether): 150 ppm.

[0132] The copper electroplating solution of Example 2 was used to fill an electroplated substrate having a groove structure with a diameter of 40 nm to 120 nm and a depth of 100 nm to 250 nm with electroplated copper. Here, the electroplated substrate is a patterned substrate having a PVD copper seed layer, the electroplating temperature is room temperature, and a three-step current method is used in the electroplating process. In the first step, the current density is 0.65 ASD and the electroplating time is 6 seconds; in the second step, the current density is 1 ASD and the electroplating time is 40 seconds; and in the third step, the current density is 6 ASD and the electroplating time is 45 seconds.

[0133] Figures 8 and 9 are cross-sectional electron microscope images of a sample after electroplating according to Example 2 of the present invention. From Figures 8 and 9, it can be seen that when a leveling agent of polypyridine compound B is added, the copper layer surface in the high-density groove region and the low-density groove region is not very undulating, and the ratio of the average thickness of the copper layer in the high-density groove region to the average thickness of the copper layer in the low-density groove region is only 1.0, indicating a significant improvement in flatness, which greatly reduces the burden on the subsequent CMP polishing process. Furthermore, from Figures 8 and 9, it can be seen that by adding a leveling agent of polypyridine compound A to the electroplating solution, defect-free filling of small grooves and simultaneous filling with high flatness can be achieved for different sizes and distribution densities.

[0134] In the embodiment described above, in which the novel leveling agent of this invention is added to the electroplating composition and electroplated copper is filled, seam-free filling of metallic copper can be reliably performed for nano-level and submicron-level grooves of different sizes, and the leveling agent can ultimately achieve a good flatness effect by suppressing excessive copper deposition. As a result, relatively small-sized patterns are not completely filled in advance, and the undulation of the platform on the surface of the plating layer is greatly reduced, resulting in a sample with a uniform surface copper thickness and a good appearance on the substrate surface, which simplifies the subsequent polishing process and improves the reliability of the final product.

[0135] It should be understood that the terms "First," "Second," and various numbers used herein are used merely for the purpose of facilitating explanation and are not intended to limit the scope of this application.

[0136] In this application, "and / or" indicates a relationship between related things, and shows that three relationships may exist. For example, A and / or B can represent the following three cases: when only A exists, when both A and B exist, and when only B exists. A and B may be singular or plural. The letter " / " usually indicates an "or" relationship between related things.

[0137] In this application, "at least one" means one or more, and "multiple means" means two or more. "At least one of the following items (elements)" or similar expressions means any combination of these items, including any combination of each item (element) or multiple items (elements). For example, "at least one of a, b, or c" and "at least one of a, b, and c" may both represent a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c may be singular or plural.

[0138] It should be understood that the sequential numbering of the aforementioned processes does not indicate the order of implementation in the various embodiments of the present application. Some or all of the steps may be performed in parallel or sequentially. The order of implementation of the processes should be determined based on the function and internal logic of the processes and should not be construed as any limitation on the implementation process of the embodiments of the present application.

Claims

1. A leveling agent used in an electroplating solution, It is a polypyridine compound, The polypyridine compound comprises a structural unit shown in formula (I), or a protonated product of the structural unit shown in formula (I). 【Chemistry 1】 Equation (I) In the above formula (I), R 1 and R 2 Independently, (1) Substituted or unsubstituted alkylenes, (2) Substituted or unsubstituted arylenes, (3) Substituted or unsubstituted arylenealkyl, (4) Substituted or unsubstituted alkylenearyl (5) Alkylenes comprising at least one of an ether oxygen atom, an ester, and an imide (6) Arylenes comprising at least one of an ether oxygen atom, an ester, and an imide, (7) Arylene alkyls comprising at least one of an ether oxygen atom, an ester, and an imide, and (8) Alkylenearyl containing at least one of an ether oxygen atom, an ester, and an imide It is one of the following: R 3 teeth, (a) single bond, (b) Substituted or unsubstituted alkylenes, (c) Substituted or unsubstituted arylene, (d) Substituted or unsubstituted arylenealkyls, (e) Substituted or unsubstituted alkylenearyls, and (f) A bonding group comprising at least one of an ether oxygen atom, an ester, and an imide. A leveling agent that is one of the following.

2. The polypyridine compound comprises a protonation product of the structural unit shown in formula (I) and a halide ion. The leveling agent according to claim 1, wherein the halide ion comprises one of fluoride ions, chloride ions, bromide ions, and iodide ions.

3. R 1 , R 2 and R 3 The leveling agent according to claim 1 or 2, wherein the amount of carbon atoms in the substituted or unsubstituted alkylene is 1 to 30, and the amount of carbon atoms in the substituted or unsubstituted arylene is 6 to 30.

4. Said alkylene containing an ether oxygen atom is -(R 4 O) x -L-(R 5 O) y -R 5 -, represented by Here R 4 and R 5 The leveling agent according to claim 1 or 2, wherein x is the same or different alkylene, x is an integer greater than or equal to 0, y is an integer greater than or equal to 1, and L represents a single bond or at least one ether oxygen block.

5. A composition used in an electroplating solution, It includes a metal ion source and a leveling agent, The leveling agent is a polypyridine compound, and the polypyridine compound includes a structural unit shown in formula (I), or a protonated product of the structural unit shown in formula (I). 【Chemistry 2】 Equation (I) Here in equation (I), R 1 and R 2 Independently, (1) Substituted or unsubstituted alkylenes, (2) Substituted or unsubstituted arylenes, (3) Substituted or unsubstituted arylenealkyl, (4) Substituted or unsubstituted alkylenearyl (5) Alkylenes comprising at least one of an ether oxygen atom, an ester, and an imide (6) Arylenes comprising at least one of an ether oxygen atom, an ester, and an imide, (7) Arylene alkyls comprising at least one of an ether oxygen atom, an ester, and an imide, and (8) Alkylenearyl containing at least one of an ether oxygen atom, an ester, and an imide It is one of the following: R 3 teeth, (a) single bond, (b) Substituted or unsubstituted alkylenes, (c) Substituted or unsubstituted arylene, (d) Substituted or unsubstituted arylenealkyls, (e) Substituted or unsubstituted alkylenearyls, and (f) A bonding group comprising at least one of an ether oxygen atom, an ester, and an imide. A composition that is one of the following.

6. The composition according to claim 5, wherein the concentration of the leveling agent is in the range of 1 ppm to 100 ppm.

7. The composition according to claim 5, further comprising one or more accelerators, inhibitors, or inorganic additives.

8. The accelerator comprises one or more of 3-mercapto-1-propanesulfonic acid, sodium polydithiodipropanesulfonate, or sodium N,N-dimethyldithiocarboxamidepropanesulfonate. The composition according to claim 7, wherein the concentration of the accelerator in the composition is in the range of 1 ppm to 50 ppm.

9. The inhibitor comprises one or more of polyethylene glycol, polypropylene glycol, block copolymer PEO-PPO-PEO, block copolymer PPO-PEO-PPO, random copolymer of EO and PO, or propylene glycol block polyether. The composition according to claim 7, wherein the concentration of the inhibitor in the composition is in the range of 1 ppm to 2000 ppm.

10. The inorganic additive contains chloride ions, The composition according to claim 7, wherein the concentration of chloride ions in the composition is in the range of 1 ppm to 100 ppm.

11. The composition according to claim 5, further comprising at least one acid, wherein the at least one acid comprises sulfuric acid and / or methyl sulfonate.

12. The composition according to claim 11, wherein the concentration of the at least one acid in the composition is in the range of 1 g / L to 100 g / L.

13. The composition according to claim 5 or 6, wherein the metal ion source comprises one of a copper ion source, a nickel ion source, a tin ion source, a cobalt ion source, a ruthenium ion source, or a silver ion source.

14. The copper ion source comprises copper sulfate pentahydrate and / or copper methyl sulfonate. The composition according to claim 13, wherein the concentration of the copper ion source in the composition is in the range of 1 g / L to 100 g / L with respect to copper ions.

15. Application of the leveling agent according to claim 1 to metal electroplating.

16. The application of claim 15, wherein the electroplated metal includes one of the following: electroplated copper and copper alloys, electroplated nickel and nickel alloys, electroplated tin and tin alloys, electroplated cobalt and cobalt alloys, electroplated ruthenium and ruthenium alloys, or electroplated silver and silver alloys.

17. The application according to claim 15 or 16, wherein the electroplated metal includes all electroplated metals used to fill holes or grooves in an electronic substrate.

18. The application of claim 15 or 16, wherein the electroplated metal includes an electroplated metal in a printed circuit board preparation process, an electroplated metal in an integrated circuit metal interconnection process, or an electroplated metal in an electronic packaging process.

19. It is an electronic circuit board, It includes a base layer and a metal layer disposed on the base layer, The aforementioned metal layer is formed by electroplating of the composition. The composition comprises a metal ion source and a leveling agent. The leveling agent is a polypyridine compound, and the polypyridine compound includes a structural unit shown in formula (I), or a protonated product of the structural unit shown in formula (I). 【Transformation 3】 Equation (I) Here, in equation (I), R 1 and R 2 Independently, (1) Substituted or unsubstituted alkylenes, (2) Substituted or unsubstituted arylenes, (3) Substituted or unsubstituted arylenealkyl, (4) Substituted or unsubstituted alkylenearyl (5) Alkylenes comprising at least one of an ether oxygen atom, an ester, and an imide (6) Arylenes comprising at least one of an ether oxygen atom, an ester, and an imide, (7) Arylene alkyls comprising at least one of an ether oxygen atom, an ester, and an imide, and (8) Alkylenearyl containing at least one of an ether oxygen atom, an ester, and an imide It is one of the following: R 3 teeth, (a) single bond, (b) Substituted or unsubstituted alkylenes, (c) Substituted or unsubstituted arylene, (d) Substituted or unsubstituted arylenealkyls, (e) Substituted or unsubstituted alkylenearyls, and (f) A bonding group comprising at least one of an ether oxygen atom, an ester, and an imide. An electronic circuit board that is one of the following.

20. The electronic substrate according to claim 19, wherein the metal layer comprises one of the following: a copper or copper alloy layer, a nickel or nickel alloy layer, a tin or tin alloy layer, a cobalt or cobalt alloy layer, a ruthenium or ruthenium alloy layer, and a silver or silver alloy layer.

21. An electronic device using the electronic circuit board described in claim 19.

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