Leveling agents, compositions, and their applications

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]

[0001] This application claims priority to Chinese Patent Application No. 202211056293.6, entitled "Leveling Agent, Composition, and Application Thereof," filed with the State Intellectual Property Office of the People's Republic of China on August 31, 2022, the entire contents of which are incorporated herein by reference.

[0002] FIELD OF THE INVENTION Embodiments of the present application relate to the field of metal electroplating technology, and in particular to leveling agents, compositions, and their applications. [Background technology]

[0003] In the manufacturing process of the electronics industry, metallic copper is widely used as an interconnect material in fields such as integrated circuits, electronic packages, and printed circuit boards due to its characteristics such as good electrical conductivity and good ductility. Filling holes or grooves, such as trenches, plated-through holes, or blind via holes of different sizes, with electroplated copper is accomplished through the electroplating process, so that electrical interconnections between copper wires and interlayer structures can be achieved. Summary of the Invention [Problem to be solved by the invention]

[0004] However, during the process of electroplating copper into holes or trenches, the current distribution inside and outside the holes is uneven, resulting in a discharge effect at the top of the holes, resulting in different copper deposition rates inside and outside the holes. As a result, the electroplated copper layer tends to seal the holes 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 these 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 holes, achieving the effect of "promoting deposition at the bottom of the holes and suppressing deposition at the top of the holes" when filling the holes or trenches with electroplated copper, ultimately achieving defect-free superfilling (as shown in Figure 1c). However, even after superfilling the holes or trenches, copper continues to deposit on the top of the pattern, resulting in bump defects at the top, as shown in Figures 1a, 1b, and 1c. As a result, during filling of holes or trenches 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-planar copper layer as shown in FIG. 2. This adversely affects 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 planar electroplated interconnect layer, placing increasing demands on the chemistry of electroplating solutions used to fill small-sized trenches. Therefore, it is necessary to provide an additive. The additive can inhibit copper deposition to a certain extent, facilitating defect-free filling, and also planarize and uniformize the surface of the plating layer, thereby 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, making the subsequent CMP process easier. This allows for defect-free filling with high surface planarity. [Means for solving the problem]

[0005] In view of this, one embodiment of the present application provides a leveling agent, which is used in an electroplating composition for filling interconnection structures in electronic substrates, thereby enabling defect-free metal filling of small-sized holes or grooves, improving the surface flatness of the resulting metal plating layer with different density distribution regions, and suppressing the impurity content in the plating layer, thereby simplifying chemical mechanical polishing and improving the reliability of the plating layer.

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

[0007] [ka] Formula (I) In the formula (I), R and R 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, arylene alkyl 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 R is any one of a single bond, substituted or unsubstituted alkylene, substituted or unsubstituted arylene, substituted or unsubstituted arylene alkyl, substituted or unsubstituted alkylene aryl, and a linking group containing an ether oxygen atom, an ester, and / or an imide. The leveling agent in this embodiment of the present application is, in particular, a polypyridine compound containing an ester. Leveling agents are added to electroplating compositions and used to fill holes or trenches with electroplated metal in semiconductor manufacturing processes, thereby preventing excessive metal deposition to a certain extent. This ensures defect-free metal filling of holes or trenches, prevents relatively small holes or trenches from being completely filled in advance, reduces thickness differences between electroplated metal layers in distribution areas with different densities, significantly reduces platform waviness on the surface of the plating layer, and provides a better planarization effect, thereby facilitating subsequent CMP processes. Furthermore, the amount of impurities in the plating layer is reduced, improving the reliability of the plating layer.

[0008] In an embodiment of the present application, the polypyridine compound comprises a protonation product of the structural unit represented by formula (I) and a halide ion. In the present example, the halide ion comprises any one of 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 by formula (I-1). It can be understood that each substituent in formula (I-1) corresponds to the corresponding substituent in formula (I).

[0009] [ka] Formula (I-1) In an embodiment 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 alkylene aryl containing one or more ether oxygen atoms. In this case, R1 is a group containing an ether oxygen atom, which can better suppress excessive metal deposition, reduce the thickness difference between electroplated metal layers in distribution areas with different densities, and achieve a better planarization effect.

[0011] In an embodiment of the present application, the alkylene containing an ether oxygen atom is -(R4O) x -L-(RO) y -R5- is expressed as Here, R4 and R5 are the same or different alkylenes, x is an integer of 0 or greater, y is an integer of 1 or greater, 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 range from 1 to 300. In some embodiments, the values ​​of x and y may range from 1 to 100. In some embodiments, the values ​​of x and y may range from 1 to 30. Longer R1 chains exhibit stronger inhibitory effects on electroplated metals and better leveling effects in denser distribution areas. Therefore, in this embodiment 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 R is ethylidene, where R is -(CHCHO). y In an embodiment of the present application, x is equal to 0, L represents a single bond, and R is isopropylidene. In this case, R is -(CHCHCHO). y In the examples of the present application, x is an integer of 1 or more, L represents a single bond, R4 is ethylidene, and R5 is isopropylidene. In this case, R1 is -(CH2CH2O) x -(CH2CHCH2O) y In the foregoing embodiment, L represents a single bond. In some embodiments herein, L may alternatively be at least one ether oxygen block. For example, in some embodiments, L may be one ether oxygen block -(RO) k In some embodiments, L is a group consisting of two ether oxygen blocks -(RO) k -(R7O) l -, and k and l are integers equal to or greater than 1.

[0014] In the present embodiment, the linking group containing an ether oxygen atom, an ester, and / or an imide in R3 may be, in particular, an alkylene containing an ether oxygen atom, an ester, and / or an imide, an arylene containing an ether oxygen atom, an ester, and / or an imide, an arylene alkyl containing an ether oxygen atom, an ester, and / or an imide, or an alkylene aryl containing an ether oxygen atom, an ester, and / or an imide.

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

[0016] [ka] Formula (a)

[0017] [ka] Formula (b)

[0018] [ka] Formula (c) The leveling agent includes a polypyridine compound, and the polypyridine compound includes a protonation product of a structural unit shown in formula (I) or a structural unit of formula (I).

[0019] [ka] Formula (I) In formula (I), R1 is 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, arylene alkyl 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. In formula (b), X and X are the same or different halide atoms, and R is 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, arylene alkyl 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. In formula (c), R is any one of a single bond, substituted or unsubstituted alkylene, substituted or unsubstituted arylene, substituted or unsubstituted arylene alkyl, substituted or unsubstituted alkylene aryl, and a linking group containing an ether oxygen atom, an ester, and / or an imide.

[0020] In formula (I), R and R 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, arylene alkyl 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. R is a single bond, substituted or unsubstituted alkylene, substituted or unsubstituted arylene, substituted or unsubstituted arylene alkyl, substituted or unsubstituted alkylene aryl, and a linking group containing an ether oxygen atom, an ester, and / or an imide.

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

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

[0023] In an embodiment 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, as shown in formula (a), may have a structure as shown in 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 greater.

[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 aspect of the present embodiment, a composition is provided, the composition being an electroplating composition, the electroplating composition comprising a metal ion source and a leveling agent, the leveling agent being a leveling agent according to the first aspect of the present embodiment or a leveling agent obtained using a preparation method according to the second aspect of the present embodiment.

[0029] In an embodiment of the present 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 to help obtain a suitable metal deposition rate and to better achieve defect-free, high-planarity filling of small holes or trenches across the entire substrate, thereby facilitating the production of fine wiring and improving the reliability of electronic products.

[0030] In an embodiment of the present application, the electroplating composition further includes one or more of an accelerator, an inhibitor, or an inorganic additive. The leveling agent, in cooperation with the accelerator, inhibitor, or the like, significantly reduces 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 small-sized grooves can be filled defect-free and with high planarity across the entire substrate, thereby reducing the technical difficulty of the subsequent polishing process.

[0031] In an embodiment of the present application, the accelerator comprises one or more of sodium 3-mercapto-1-propanesulfonate (MPS), sodium polydithiodipropanesulfonate (SPS), or sodium N,N-dimethyl-dithiocarboxamidopropanesulfonate (DPS), and the concentration of the accelerator in the electroplating composition ranges from 1 ppm to 50 ppm. The addition of the accelerator promotes metal deposition at the bottom of the trenches and refines the grain of the metal layer.

[0032] In an embodiment 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 ranges from 1 ppm to 2000 ppm. The addition of the inhibitor inhibits rapid deposition of surface copper, prevents premature sealing of holes or trenches, and promotes obtaining a thin surface copper after copper plating.

[0033] In an embodiment of this application, the inorganic additive includes chloride ions, and the concentration of chloride ions in the electroplating composition ranges from 1 ppm to 100 ppm. The addition of chloride ions densifies and refines the crystals of the plating layer, preventing them from becoming coarse.

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

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

[0036] In embodiments of the present application, the metal ion source comprises any 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. When a certain metal layer is pre-deposited, it is understood that the metal ion source in the electroplating composition correspondingly comprises a metal ion source corresponding to the metal element in the pre-deposited metal layer.

[0037] In an embodiment of this 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 ranges from 1 g / L to 100 g / L of copper ions. Controlling the copper ion source within a suitable range helps to balance the deposition rate, brightness, and planarity of the resulting copper plating layer.

[0038] In a fourth aspect of the present embodiment, there is provided the application of a leveling agent according to the first aspect or a leveling agent obtained using the preparation method according to the second aspect, or the application of a composition according to the third aspect in metal electroplating.

[0039] In embodiments of the present application, the electroplated metal includes any one of copper and copper alloys, nickel and nickel alloy electroplating, tin and tin alloy electroplating, cobalt and cobalt alloy electroplating, ruthenium and ruthenium alloy electroplating, or silver and silver alloy electroplating.

[0040] In embodiments of the present application, electroplated metals include all electroplated metals used to fill holes or trenches in electronic substrates. The electronic substrate may be a common substrate, a printed circuit board, a package substrate, etc. The holes or trenches include grooves and / or through holes, which 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 interconnect process, or electroplating of metal in an electronic packaging process. In particular, the electroplated metal may be electroplated metal in processes such as damascene trench filling, silicon plated through-hole filling, substrate redistribution, metal bump deposition, or hole or trench filling.

[0042] The leveling agent provided in the embodiments of the present application can be used in all metal electroplating processes to fill holes or grooves in electronic substrates, achieving defect-free filling of nano-sized holes or grooves, reducing the thickness difference between high-density interconnect pattern areas and low-density interconnect pattern areas of the copper interconnect layer, making the surface of the plating layer flatter and more uniform, improving the uniformity of electroplating across the entire electronic substrate, and simplifying the subsequent CMP process. It also facilitates the production of fine wiring, improving the reliability of electronic products, and more effectively meeting the manufacturing requirements of high-density interconnect products with simple processes and low costs.

[0043] In a fifth aspect of an embodiment of the present application, there is provided a metal electroplating method, the method comprising: The method includes contacting a substrate to be electroplated with a composition according to the third aspect of the present embodiment, and applying a current to the substrate to be electroplated to perform electroplating and form a metal layer on the substrate to be electroplated.

[0044] In the present embodiment, the electroplating process conditions are: electroplating temperature in the range of 10° C. to 40° C.; current density in the range of 0.5 ASD to 6 ASD; and electroplating time in the range of 10 to 200 seconds.

[0045] In an embodiment of the present application, the 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 an embodiment of the present application, holes or trenches are provided on a substrate to be electroplated, and the metal layer includes an intra-hole filling layer that fills the holes or trenches and a surface deposition layer that is deposited around the holes or trenches.

[0047] In a sixth aspect of the present application, there is provided an electronic circuit board comprising a base layer and a metal layer disposed on the base layer, the metal layer being formed by electroplating a composition according to the third aspect of the present application or using a method according to the fifth aspect.

[0048] In embodiments of the present application, the metal layer includes any one of 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] The present embodiment further provides an electronic device including an electronic board according to a sixth aspect of the present embodiment. [Brief explanation of the drawings]

[0050] [Figure 1a] FIG. 1 is a diagram of a void defect formed by filling a hole or trench with electroplated copper. [Figure 1b] FIG. 1 is a diagram of a seam defect formed by filling a hole or groove with electroplated copper. [Figure 1c]FIG. 1 is a diagram of superfilling formed by filling holes or trenches with electroplated copper. [Figure 2] FIG. 1 illustrates filling holes or trenches with electroplated copper to form a non-planar copper layer in the prior art. [Figure 3] 1 is a diagram of a process for forming a copper interconnect layer in a semiconductor process. [Figure 4] 1 is a diagram of a substrate structure having multiple copper interconnect layers. [Figure 5] 1 is a diagram of a structure of an electronic substrate 100 according to an embodiment of the present application. [Figure 6a] 1 is an electron microscope photograph of a cross section of an electroplated sample according to a comparative example. [Figure 6b] FIG. 6b is a partial enlarged view of FIG. 6a. [Figure 7] 1 is an electron microscope photograph of a cross section of a sample after electroplating according to embodiment 1 of the present application. [Figure 8] 1 is an electron microscope photograph of a cross section of a sample after electroplating according to embodiment 2 of the present application. [Figure 9] 1 is an electron microscope photograph of a cross section of a sample after electroplating according to embodiment 2 of the present application. DETAILED DESCRIPTION OF THE INVENTION

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

[0052] FIG. 3 illustrates a process for forming a copper interconnect layer in a semiconductor process. In FIG. 3, 10a denotes a patterned substrate. The patterned substrate 10a includes a substrate 11 and a patterned dielectric layer 21, with multiple grooves 2 arranged in the patterned dielectric layer 21. After electroplating and copper deposition on the patterned substrate 10a, the multiple grooves 2 in the dielectric layer 21 are filled with copper, forming a copper layer 22, resulting in an electroplated substrate 10b. The copper layer 22 includes a hole-filling layer filling the grooves 2 and a surface deposition layer covering 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 by the CMP process. After removing the surface deposition layer of the copper layer 22 from the electroplated substrate 10b through the CMP process, a copper interconnect layer 20 that has been processed by the CMP process, i.e., a CMP-processed substrate 10c, is obtained. In actual practice, as shown in FIG. 4, a substrate 10c processed by the CMP process may be further prepared with a copper interconnect layer. 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 for the hole-filling layer in the groove 2 to be free of defects such as voids or seams, as shown in FIG. 3. The ideal case for the electroplating and copper deposition process to facilitate the implementation of the CMP treatment process is the copper layer 22 shown in the electroplated substrate 10b in FIG. 3. The difference in thickness between the copper interconnect layer in the high-density interconnect pattern area and the copper interconnect layer in the low-density interconnect pattern area is small, the surface of the copper layer 22 as a whole is relatively flat, and the overall thickness of the copper layer 22 is relatively small. However, using current electroplating solution chemistries, it is difficult to form a defect-free copper interconnect layer with high surface planarity, and 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 high-density interconnect pattern areas tends to deviate significantly from the thickness of the copper interconnect layer in low-density interconnect pattern areas as shown in Figure 2.A high-density interconnect pattern region is a region in an interconnect layer having a relatively high density of interconnect patterns (e.g., holes or grooves) (including a certain amount of holes or grooves, or a partial area of ​​all holes or grooves). A low-density interconnect pattern region is a region in an interconnect layer having a relatively low density of interconnect patterns (e.g., holes or grooves).

[0053] Furthermore, as semiconductor process precision improves, device feature sizes shrink, and distribution designs become increasingly complex, making it increasingly difficult to obtain defect-free, highly planar copper interconnect layers. Therefore, the requirements for the chemicals in electroplating solutions used to fill small-sized trenches are becoming more stringent. To achieve defect-free filling of small-sized trenches, one embodiment of the present application provides a leveling agent to reduce the thickness difference between high-density interconnect pattern regions and low-density interconnect pattern regions in the copper interconnect layer, make the surface of the plating layer more flat and uniform, simplify the subsequent CMP process, and achieve defect-free filling with high surface planarity. The leveling agent can inhibit metal deposition to a certain extent, thereby enabling defect-free, highly planar filling of small-sized holes or trenches (including trenches 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] Formula (I) In formula (I), R and R 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, arylene alkyl 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. R is a single bond, substituted or unsubstituted alkylene, substituted or unsubstituted arylene, substituted or unsubstituted arylene alkyl, substituted or unsubstituted alkylene aryl, and a linking group containing an ether oxygen atom, an ester, and / or an 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 the semiconductor manufacturing process to fill holes or trenches with electroplated metal, preventing excessive metal deposition to a certain extent. In this way, defect-free metal filling of holes or trenches is achieved, and relatively small holes or trenches are not completely filled in advance. This reduces the thickness difference between electroplated metal layers in distribution areas with different densities, greatly suppresses platform waviness on the surface of the plating layer, and achieves a better planarization effect. This facilitates the subsequent CMP process. The polymer in the leveling agent in this embodiment of the present application has a stable molecular structure, thereby reducing the impurity content in the resulting plating layer and improving the reliability of the plating layer.

[0057] In an embodiment 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 any one of a fluoride ion, a chloride ion, a bromide ion, and an iodide ion. The protonation product of the structural unit shown in formula (I) can 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 in formula (I) - are the same halide ions, which makes it easy to prepare the leveling agent.

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

[0059] [ka] Formula (II) In the examples of the present application, the amount of carbon atoms in the substituted or unsubstituted alkylene in R1, R2, and R3 may range from 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 examples of the present application, the amount of carbon atoms in the substituted or unsubstituted arylene in R1, R2, and R3 may range from 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 some embodiments, the amount of carbon atoms in the substituted or unsubstituted arylene alkyl in R1, R2, and R3 may range from 7 to 40. In some embodiments, the amount of carbon atoms in the substituted or unsubstituted arylene alkyl 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. In some embodiments, the amount of carbon atoms in the substituted or unsubstituted alkylene aryl in R1, R2, and R3 may range from 7 to 40. In some embodiments, the amount of carbon atoms in a substituted or unsubstituted alkylenearyl can 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 present application, in R1, R2 and R3, the substituents in the substituted alkylene, substituted arylene, substituted arylene alkyl and substituted alkylene aryl may be, but are not limited to, halide atoms.

[0063] In the present embodiment, the amount of carbon atoms in the alkylene containing ether oxygen atoms, ester, and / or imide in R1 may range from 2 to 30, and the specific amount of carbon atoms is, 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, ester, and / or imide may range from 6 to 30, and the specific amount of carbon atoms is, 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 the arylene alkyl, including ether oxygen atoms, ester, and / or imide, ranges from 7 to 40, and specifically the amount of carbon atoms is, 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 the alkylene aryl, including the ether oxygen atoms, ester, and / or imide, can range from 7 to 40, and specifically the amount of carbon atoms is, 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.An alkylene containing an ether oxygen atom, an ester, and / or an imide is an alkylene containing one or more ether oxygen atoms, esters, or imides; an arylene containing an ether oxygen atom, an ester, or an imide is an arylene containing one or more ether oxygen atoms, esters, and / or imides; an arylene alkyl containing an ether oxygen atom, an ester, and / or an imide is an arylene alkyl containing one or more ether oxygen atoms, esters, and / or imides; an alkylene aryl containing an ether oxygen atom, an ester, and / or an imide is an alkylene aryl containing one or more ether oxygen atoms, esters, and / or imides.

[0064] In some embodiments of the present application, R1 may be an alkylene having 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 an ether oxygen atom, which can better suppress excessive metal deposition, reduce the thickness difference between electroplated metal layers in distribution areas with different densities, and achieve better flatness.

[0065] In some embodiments of the present application, R1 can be an alkylene containing an ether oxygen atom, and the alkylene containing an ether oxygen atom is -(RO) x -L-(RO) yThe formula may be represented by -R5-, where R4 and R5 may be the same or different alkylenes, 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. R4 and R5 may be alkylenes having 2 to 10 carbon atoms, such as ethylidene, propylidene, or isopropylidene, among others. The values ​​of x and y may range from 1 to 300. In some embodiments, the values ​​of x and y may range from 1 to 100. In some embodiments, the values ​​of x and y may range from 1 to 30. In some embodiments, the values ​​of x and y may 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, among others. Longer R1 chains exhibit stronger inhibitory effects on electroplated metals and better leveling in denser distribution areas. 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 an embodiment of the present application, x is equal to 0, L represents a single bond, and R5 is ethylidene, where R1 is -(CH2CH2O) y In an embodiment of the present application, x is equal to 0, L represents a single bond, and R is isopropylidene, where R is -(CHCHCHO). y In the examples of the present application, x is an integer of 1 or more, L represents a single bond, R4 is ethylidene, and R5 is isopropylidene. In this case, R1 is -(CH2CH2O) x -(CH2CHCH2O) y In the foregoing embodiment, L represents a single bond. Alternatively, in some embodiments herein, L may be at least one ether oxygen block. For example, in some embodiments, L may be one ether oxygen block -(RO) kIn some embodiments, L is a group consisting of two ether oxygen blocks -(RO) k -(R7O) l -, and k and l are integers equal to or greater than 1.

[0067] In the present embodiment, the linking group containing an ether oxygen atom, an ester, and / or an imide in R3 may be, in particular, an alkylene containing an ether oxygen atom, an ester, and / or an imide, an arylene containing an ether oxygen atom, an ester, and / or an imide, an arylene alkyl containing an ether oxygen atom, an ester, and / or an imide, or an alkylene aryl containing an ether oxygen atom, an ester, and / or an imide. The selection of the aforementioned chemical groups is similar to that for R1 and R2, and the details will not be repeated here. In some embodiments, the linking group containing an imide may be -HN-C(=O)-RC(=O)-NH-, where R may be a substituted or unsubstituted alkylene.

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

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

[0070] Correspondingly, an embodiment of the present application further provides a method for preparing a leveling agent, the method including steps S101 and S102: Step S101: At a first temperature, a compound having hydroxyl groups at both ends and represented by formula (a) is reacted with a compound containing an acyl halide group and 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, wherein the leveling agent includes a polypyridine compound, and the polypyridine compound includes a protonation product of the structural unit represented by formula (I) or a structural unit represented by formula (I).

[0071] [ka] Formula (a)

[0072] [ka] Formula (b)

[0073] [ka] Formula (c)

[0074] [ka] Formula (I) In formula (a), R1 is 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, arylene alkyl 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 in formula (b), X1 and X are , the same or different halide atoms, and R2 is 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, arylene alkyl 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. In formula (c), R3 is any one of a single bond, substituted or unsubstituted alkylene, substituted or unsubstituted arylene, substituted or unsubstituted arylene alkyl, substituted or unsubstituted alkylene aryl, and linking groups containing an ether oxygen atom, an ester, and / or an imide.

[0075] 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, arylene alkyl 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. R3 is a single bond, substituted or unsubstituted alkylene, substituted or unsubstituted arylene, substituted or unsubstituted arylene alkyl, substituted or unsubstituted alkylene aryl, and a linking group containing an ether oxygen atom, an ester, and / or an imide.

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

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

[0078] [ka] Formula (II) X in formula (II) - is derived from the halide atom X in formula (b).

[0079] In some embodiments of the present application, the compound having hydroxyl groups at both ends and represented by formula (a) may have a 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 greater and may range, for example, from 1 to 300. In certain embodiments, the values ​​of m and n 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.

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

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

[0082] [ka] Formula (a-3) In the present embodiment, in step S101, the first temperature 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, a solvent such as dichloromethane may be used.

[0083] In the present example, in step S102, the second temperature 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] In one embodiment of the present application, there is further provided an electroplating composition, which in an embodiment of the present application includes a metal ion source and the above-described leveling agent. The electroplating composition may be used as an electroplating solution for electroplating and depositing a metal layer.

[0086] In the present examples, the concentration of the leveling agent in the electroplating composition ranges from 1 ppm to 100 ppm. In some embodiments, the concentration of the leveling agent ranges from 2 ppm to 80 ppm. In some embodiments, the concentration of the leveling agent ranges from 5 ppm to 50 ppm. In some embodiments, the concentration of the leveling agent ranges from 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. Controlling the concentration of the leveling agent in the electroplating composition within a suitable range helps to obtain an adequate metal deposition rate and improves defect-free, highly planar filling of small holes or trenches across the entire substrate, thereby facilitating the fabrication of fine lines and improving the reliability of electronic products.

[0087] In the present embodiment, the electroplating composition further comprises one or more of an accelerator, an inhibitor, or an inorganic additive. The leveling agent, in cooperation with the accelerator, inhibitor, or the like, significantly reduces the surface roughness of the copper layer. It can also make the thickness of the surface copper uniform in areas with different distribution densities, thereby enabling defect-free, high-flatness filling of small-sized holes or trenches across the entire substrate, thereby reducing the technical difficulty of the subsequent polishing process.

[0088] In embodiments of the present application, the accelerator includes one or more of sodium 3-mercapto-1-propanesulfonate (MPS), sodium polydithiodipropanesulfonate (SPS), or sodium N,N-dimethyl-dithiocarboxamidopropanesulfonate (DPS). The addition of the accelerator promotes metal deposition at the bottom of the trench and refines the grain size of the metal layer. In embodiments of this application, the accelerator concentration in the electroplating composition may range from 1 ppm to 50 ppm. In some embodiments, the accelerator concentration in the electroplating composition may range from 2 ppm to 40 ppm. In some embodiments, the accelerator concentration in the electroplating composition may range from 5 ppm to 35 ppm. In some embodiments, the accelerator concentration in the electroplating composition may range from 10 ppm to 30 ppm.

[0089] In embodiments of the present 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 copolymer of polyoxyethylene (EO) and polyoxypropylene (PO), or propylene glycol block polyether. The addition of an inhibitor can inhibit rapid deposition of surface copper, prevent premature sealing of holes or channels, and facilitate obtaining a thin surface copper after copper plating. In embodiments of this application, the concentration of the inhibitor in the electroplating composition can range from 1 ppm to 2000 ppm. In some embodiments, the concentration of the inhibitor in the electroplating composition ranges from 10 ppm to 1000 ppm. In some embodiments, the concentration of the inhibitor in the electroplating composition ranges from 100 ppm to 1000 ppm. In some embodiments, the concentration of the inhibitor in the electroplating composition ranges from 150 ppm to 500 ppm. In some embodiments of this application, the inorganic additive includes chloride ions, and the concentration of chloride ions in the electroplating composition ranges from 1 ppm to 100 ppm. In some embodiments, the concentration of chloride ions 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 plated layer that is dense, fine, and not rough.

[0090] In some embodiments, the electroplating composition further includes at least one acid, and the at least one acid includes sulfuric acid and / or methyl sulfonate. In some embodiments, the concentration of the at least one acid in the electroplating composition ranges from 1 g / L to 100 g / L. In some embodiments, the concentration of the at least one acid in the electroplating composition can 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. An appropriate acid system and acid concentration can help achieve a suitable electroplating rate.

[0091] In the present embodiment, the metal ion source includes any one of a copper ion source, a nickel ion source, a tin ion source, a cobalt ion source, a ruthenium ion source, and a silver ion source. When a certain type of metal layer is pre-deposited, it can be understood that 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, when a metallic copper layer is pre-deposited, the metal ion source includes a copper ion source.

[0092] In embodiments of the present application, the copper ion source includes copper sulfate pentahydrate and / or copper methyl sulfonate. Electroplating using an acid system of copper ion sources provides high current efficiency, is environmentally friendly, and, due to the cooperation between various additives, improves blind via hole filling. In embodiments of the present application, the concentration of the copper ion source in the electroplating composition ranges from 1 g / L to 100 g / L relative to the copper icon. In some embodiments, the concentration of the copper ion source in the electroplating composition may be 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 relative to the copper icon. Controlling the copper ion source within a suitable range promotes a balance between the deposition rate, brightness, and planarity of the resulting copper plating layer.

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

[0094] An embodiment of the present application further provides for the application of the leveling agent and / or electroplating composition in a metal electroplating process, where the electroplated metal may be any one of 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 electroplated metal in a printed circuit board preparation process, electroplated metal in an integrated circuit metal interconnect process, or electroplated metal in an electronic packaging process. Specifically, the electroplated metal may be plated metal in processes such as damascene trench filling, silicon plated through-hole filling, substrate redistribution, metal bump deposition, or through-hole filling.

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

[0097] The leveling agent provided in the embodiments of the present application can be used in all metal electroplating processes to fill holes or grooves on electronic substrates, achieving defect-free filling of nano-sized holes or grooves and reducing the thickness difference between high-density and low-density interconnect pattern areas of the copper interconnect layer, resulting in a flatter and more uniform surface for the plating layer, improving the uniformity of electroplating across the entire electronic substrate, and simplifying the subsequent CMP process. It also facilitates the production of fine wiring, improving the reliability of electronic products, and better meeting the manufacturing requirements for high-density interconnect products with a low-cost, simple process.

[0098] In one embodiment of the present application, there is further provided a metal electroplating method comprising the steps of: In an embodiment of the present application, a substrate to be electroplated is brought into contact with the electroplating composition described above, and a current is applied to the substrate to be electroplated, thereby performing electroplating and forming a metal layer 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, forming a conductive loop with a soluble or insoluble anode, thereby effecting metal deposition on the substrate to be electroplated.

[0100] In the present embodiment, holes or trenches are provided on a substrate to be electroplated, and the metal layer includes a hole-filling layer that fills the holes or trenches and a surface deposition layer that is deposited around the holes or trenches. The holes or trenches include trenches and / or through-holes, and the through-holes may include one or more of plated-through holes, blind via holes, or buried via holes.

[0101] In the present embodiment, the horizontal size of the hole or groove is 28 nm to 1.2 μm, and its depth is 100 nm to 300 nm. Specifically, the horizontal size of the hole or groove 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. The holes or grooves on the substrate to be plated may have different horizontal sizes and 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 the present embodiment, regions having different hole or groove distribution densities, including, for example, regions with high hole or groove distribution density and regions with low hole or groove distribution density, may be disposed on the substrate to be electroplated.

[0103] Typically, before electroplating is performed, a metallization process is performed on the interior walls of the holes or trenches, whereby a metal seed layer, such as a copper seed layer, is chemically plated onto the interior walls of the holes or trenches.

[0104] In the present embodiment, the electroplating process conditions are as follows: electroplating temperature in the range of 10° C. to 40° C., current density in the range of 0.5 ASD to 6 ASD, and electroplating time in the range of 10 to 200 seconds.

[0105] In this embodiment, the electroplating process includes a first electroplating step, a second electroplating step, and a third electroplating step. 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. 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 this embodiment, the step-by-step electroplating process can improve defect-free filling and obtain a suitable thickness of the surface metal layer. Copper electroplating is used as an example. The first electroplating step can improve copper seed layer repair, the second electroplating step can improve seam filling, and the third electroplating step can thicken 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 above in the embodiments of the present application, or by using the metal electroplating method described above in the embodiments of the present application.

[0107] In the present embodiment, the metal layer 102 includes any one of 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 the present embodiment, the base layer 101 includes a substrate 1011 and a dielectric layer 1012, the base layer 101 is provided with holes or trenches 103, and the metal layer 102 includes an intra-hole filling layer 1021 that fills the holes or trenches 103 and a surface deposition layer 1022 that is deposited around the holes or trenches 103. It will be understood that in some embodiments, after the surface deposition layer 1022 is removed by a CMP process, the metal layer 102 includes only the intra-hole filling layer 1021 that fills the holes or trenches 103.

[0109] In the present embodiment, a metal seed layer, for example a copper seed layer, formed by performing a metallization process on the holes or trenches 103 may further be included between the base layer 101 and the metal layer 102 .

[0110] In the present embodiment, the horizontal size of the hole or groove 103 ranges from 28 nm to 1.2 μm, and its depth ranges from 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 may have the same horizontal size and the same depth.

[0111] In embodiments of the present application, the thickness of the surface deposition layer 1022 is less than 8 μm. In embodiments of the present application, the ratio of the average thickness H1 of the surface deposition layer 1022 in the high-density interconnect pattern region to the average thickness H2 of the surface deposition layer 1022 in the low-density interconnect 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] 5 of this embodiment of the present application is a diagram of the structure of the electronic substrate 100 that has not been treated with a CMP process. In practical applications, the surface deposition layer 1022 will be removed using a polishing process.

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

[0114] Hereinafter, the embodiments of the present application will be further described 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

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

[0119] The method for preparing polypyridine compound A is as follows: (1) 50 mL of dichloromethane, 20 mmol of triethylene glycol, and 40 mmol of triethylamine are added to a three-neck flask equipped with a thermometer, a mixer, and a constant pressure dropping funnel, and the mixer is operated to control the temperature at 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 dropwise at a rate of 1 mL / min at a temperature of 0 to 10°C. After the addition is complete, continue the reaction at room temperature for 12 hours or more. Next, evaporate the reaction mixture to remove the dichloromethane, then dissolve the resulting solution with ethyl acetate and water, extract the organic phase of ethyl acetate, and wash with water. Then, evaporate the resulting solution to obtain the ester intermediate. (3) 20 mmol of the obtained ester intermediate and 20 mmol of 4,4'-bipyridine are added to a round-bottom flask equipped with a mixer, and the mixer is turned on and the temperature is raised to 120°C. After reacting for 12 hours, the temperature is lowered to room temperature to obtain the final polypyridine compound A in a solid state.

[0120] The copper electroplating solution contains the following components in the following weight 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 polydithiodipropane sulfonate): 25 ppm Inhibitor L64 (propylene glycol block polyether): 300 ppm.

[0121] In order to reflect the effect of the leveling agent provided in this embodiment of the present application, a copper electroplating solution without adding a 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 Comparative Example were used separately to electroplated copper filling on a substrate having a groove structure with a diameter of 60 to 120 nm and a depth of 120 to 250 nm. The substrate was a patterned substrate with 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 stage, the current density was 0.65 ASD and the electroplating time was 6 seconds. In the second stage, the current density was 1 ASD and the electroplating time was 40 seconds. In the third stage, the current density was 6 ASD and the electroplating time was 45 seconds.

[0123] 6(a) and 6(b) are cross-sectional electron microscope photographs of the electroplated sample according to the comparative example, and Fig. 6(b) is a partially enlarged view of Fig. 6(a). From Fig. 6(a) and Fig. 6(b), it can be seen that when no leveling agent is added, the copper layer surfaces in the high-density groove region and the low-density groove region are significantly wavy, and the ratio of the average thickness of the copper layer in the high-density groove region to that in the low-density groove region is up to 1.806, making subsequent CMP operations difficult.

[0124] Figure 7 is a cross-sectional electron microscope photograph of a sample after electroplating according to Embodiment 1 of the present application. Figure 7 shows that when the polypyridine compound A leveling agent was added, the copper layer surface in both the high- and low-density groove regions was less wavy, and the ratio of the average copper layer thickness in the high-density groove region to the average copper layer thickness in the low-density groove region was only 1.023, significantly improving flatness and significantly reducing the burden of the subsequent CMP polishing process. Figure 7 also shows that the electroplating solution using the polypyridine compound A leveling agent can achieve defect-free filling of small grooves with different sizes and distribution densities, while simultaneously achieving high-flatness filling.

[0125] Example 2 Polypyridine compound B represented by formula (1):

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

[0127] [ka] and R2 is

[0128] [ka] and R3 is

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

[0130] The method for preparing polypyridine compound B is as follows: (1) 50 mL of dichloromethane, 20 mmol of triethylene glycol, and 40 mmol of triethylamine are added to a three-neck flask equipped with a thermometer, a mixer, and a constant pressure dropping funnel, and the mixer is operated 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 rate of 1 mL / min at a temperature of 0 to 10°C. After the addition is complete, continue the reaction at room temperature for 12 hours or more. Next, evaporate the reaction mixture and remove the dichloromethane. Then, dissolve the resulting solution in ethyl acetate and water, extract the organic phase of ethyl acetate, wash with water, and evaporate the resulting solution to obtain the ester intermediate. (3) 20 mmol of the obtained ester intermediate and 20 mmol of the compound containing a bipyridine structure represented by formula (c-1) were added to a round-bottom flask equipped with a mixer, the mixer was turned on, the temperature was raised to 120°C, and the reaction was carried out for 12 hours, after which the temperature was lowered to room temperature to obtain the final polypyridine compound B in a solid state.

[0131] [ka] Formula (c-1) The copper electroplating solution contains the following components in the following weight 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 polydithiodipropane sulfonate): 25 ppm Inhibitor L65 (propylene glycol block polyether): 150 ppm.

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

[0133] 8 and 9 are cross-sectional electron microscope photographs of a sample after electroplating according to Example 2 of the present application. From FIGS. 8 and 9, it can be seen that when the leveling agent of polypyridine compound B was added, the copper layer surface in the high-density groove region and the low-density groove region was less wavy, and the ratio of the average copper layer thickness in the high-density groove region to the average copper layer thickness in the low-density groove region was only 1.0, significantly improving flatness and thereby significantly reducing the burden on the subsequent CMP polishing process. Furthermore, from FIGS. 8 and 9, it can be seen that the addition of the leveling agent of polypyridine compound A to the electroplating solution can achieve defect-free filling of small grooves with different sizes and different distribution densities, as well as simultaneous filling with high flatness.

[0134] In the above-described embodiment in which the novel leveling agent of this embodiment of the present application is added to an electroplating composition and electroplated copper is filled, it can be seen that seamless filling of metallic copper can be ensured for nano-level and submicron-level grooves of different sizes, and the leveling agent can suppress copper over-deposition, ultimately achieving good planarity. As a result, relatively small patterns are not completely filled in advance, and the waviness 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 substrate surface appearance, which simplifies the subsequent polishing process and improves the reliability of the final product.

[0135] It is understood that the terms "first," "second," and various numerals used herein are used merely for distinction purposes for ease of explanation and are not intended to limit the scope of the present application.

[0136] In this application, "and / or" represents a relationship between related entities and indicates that three relationships may exist. For example, A and / or B may represent 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 character " / " usually represents an "or" relationship between related entities.

[0137] As used herein, "at least one" means one or more, and "plurality" means two or more. "At least one of the following items" or similar expressions refers to any combination of those items, including any combination of each item or items. For example, "at least one of a, b, or c" and "at least one of a, b, and c" can both refer to a, b, c, ab (i.e., a and b), ac, bc, or abc. Here, a, b, and c can be singular or plural.

[0138] It should be understood that the sequence numbers of the above processes do not imply the order of implementation in various embodiments of the present application. Some or all of the steps may be implemented in parallel or sequentially. The order of implementation of the processes should be determined based on the functions 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, is a polypyridine compound, The polypyridine compound comprises a structural unit shown in formula (I) or a protonation product of a structural unit shown in formula (I), 【Chemical 1】 Formula (I) In the formula (I), R 1 and R 2 is 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, arylene alkyl 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; R 3 is any one of a single bond, a substituted or unsubstituted alkylene, a substituted or unsubstituted arylene, a substituted or unsubstituted arylene alkyl, a substituted or unsubstituted alkylene aryl, and a linking group containing an ether oxygen atom, an ester, and / or an imide.

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

3. R 1 , R 2 and R 3 3. The leveling agent according to claim 1, 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. The alkylene containing an ether oxygen atom is —(R 4 O) x -L- (R 5 O) y -R 5 - is expressed as where R 4 and R 5 3. The leveling agent according to claim 1 or 2, wherein: are the same or different alkylenes; x is an integer of 0 or greater; y is an integer of 1 or greater; and L represents a single bond or at least one ether oxygen block.

5. A method for preparing a leveling agent, comprising the steps of: reacting a compound having hydroxyl groups at both ends, as shown in formula (a), with a compound containing an acyl halide group, as shown in formula (b), at a first temperature to obtain an intermediate; Next, at a second temperature, the intermediate is reacted with a compound containing a bipyridine structure represented by formula (c) to obtain a leveling agent; and The leveling agent comprises a polypyridine compound, the polypyridine compound comprising a protonated product of a structural unit shown in formula (I) or a structural unit shown in formula (I): 【Chemistry 2】 【Chemistry 3】 【Chemistry 4】 【Chemistry 5】 Here, in formula (a), R 1 is 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, arylene alkyl 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; In formula (b), X 1 and X are the same or different halide atoms, R 2 is 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, arylene alkyl 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; In formula (c), R 3 is any one of a single bond, substituted or unsubstituted alkylene, substituted or unsubstituted arylene, substituted or unsubstituted arylene alkyl, substituted or unsubstituted alkylene aryl, and linking groups containing an ether oxygen atom, an ester, and / or an imide; In formula (I), R 1 and R 2 is 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, arylene alkyl 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; R 3 is any one of a single bond, a substituted or unsubstituted alkylene, a substituted or unsubstituted arylene, a substituted or unsubstituted arylene alkyl, a substituted or unsubstituted alkylene aryl, and a linking group containing an ether oxygen atom, an ester, and / or an imide.

6. 6. The method of claim 5, wherein the first temperature is in the range of -20°C to 25°C.

7. 7. The method of claim 5 or 6, wherein the second temperature is in the range of 25°C to 200°C.

8. 1. A composition comprising: a metal ion source; A leveling agent according to any one of claims 1 to 4 or obtained by the preparation method according to any one of claims 5 to 7, A composition comprising:

9. 9. The composition of claim 8, wherein in the electroplating composition, the concentration of the leveling agent ranges from 1 ppm to 100 ppm.

10. 10. The composition of claim 8 or 9, wherein the electroplating composition further comprises one or more of an accelerator, an inhibitor, or an inorganic additive.

11. the accelerator comprises one or more of 3-mercapto-1-propanesulfonic acid, sodium polydithiodipropanesulfonate, or sodium N,N-dimethyl-dithiocarboxamidopropanesulfonate; 11. The composition of claim 10, wherein the concentration of the accelerator in the composition ranges from 1 ppm to 50 ppm.

12. 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; 11. The composition of claim 10, wherein the concentration of the inhibitor in the composition ranges from 1 ppm to 2000 ppm.

13. the inorganic additive comprises chloride ions; 11. The composition of claim 10, wherein the concentration of the chloride ions in the composition ranges from 1 ppm to 100 ppm.

14. 14. The composition of claim 8, further comprising at least one acid, wherein the at least one acid comprises sulfuric acid and / or methyl sulfonate.

15. 15. The composition of claim 14, wherein the concentration of the at least one acid in the composition ranges from 1 g / L to 100 g / L.

16. 16. The composition of claim 8, wherein the metal ion source comprises any 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.

17. the copper ion source comprises copper sulfate pentahydrate and / or copper methyl sulfonate; 17. The composition of claim 16, wherein the concentration of the copper ion source in the composition ranges from 1 g / L to 100 g / L of copper ions.

18. 18. The application of a leveling agent according to any one of claims 1 to 4, or a leveling agent obtained using a preparation method according to any one of claims 5 to 7, or the application of a composition according to any one of claims 8 to 17 in metal electroplating.

19. 20. The application of claim 18, wherein the electroplated metal comprises any one of 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.

20. 20. The application of claim 18 or 19, wherein the electroplated metal includes any electroplated metal used to fill holes or grooves in an electronic substrate.

21. 21. The application of any one of claims 18 to 20, wherein the electroplated metal comprises electroplated metal in a printed circuit board preparation process, electroplated metal in an integrated circuit metal interconnect process, or electroplated metal in an electronic packaging process.

22. 1. A method of metal electroplating comprising: contacting a substrate to be electroplated with the composition of any one of claims 8 to 17; applying a current to the substrate to be electroplated to perform electroplating, thereby forming a metal layer on the substrate to be electroplated; A method comprising:

23. 23. The method of claim 22, wherein the electroplating process conditions are: electroplating temperature in the range of 10°C to 40°C, current density in the range of 0.5 ASD to 6 ASD, and electroplating time in the range of 10 seconds to 200 seconds.

24. The electroplating includes a first electroplating step, a second electroplating step, and a third electroplating step; 24. The method of claim 23, wherein in the first electroplating step, the current density ranges from 0.2 ASD to 1 ASD and the electroplating time ranges from 1 second to 15 seconds; in the second electroplating step, the current density ranges from 0.8 ASD to 2 ASD and the electroplating time ranges from 10 seconds to 100 seconds; and in the third electroplating step, the current density ranges from 2 ASD to 6 ASD and the electroplating time ranges from 10 seconds to 100 seconds.

25. The substrate to be electroplated is provided with a hole or a groove, 24. The method of claim 23, wherein the metal layer comprises an intra-hole filling layer that fills the holes or trenches and a surface deposition layer that is deposited around the holes or trenches.

26. An electronic substrate, a base layer and a metal layer disposed on the base layer; 26. An electronic substrate, wherein the metal layer is formed by electroplating the composition according to any one of claims 8 to 17, or by using the metal electroplating method according to any one of claims 22 to 25.

27. 27. The electronic substrate of claim 26, wherein the metal layer comprises any one of 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.

28. 28. An electronic device using the electronic substrate according to claim 26 or 27.

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