WO2024046395A1 - 一种整平剂、组合物及其应用 - Google Patents

一种整平剂、组合物及其应用 Download PDF

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WO2024046395A1
WO2024046395A1 PCT/CN2023/115935 CN2023115935W WO2024046395A1 WO 2024046395 A1 WO2024046395 A1 WO 2024046395A1 CN 2023115935 W CN2023115935 W CN 2023115935W WO 2024046395 A1 WO2024046395 A1 WO 2024046395A1
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group
substituted
electroplating
unsubstituted
ether oxygen
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PCT/CN2023/115935
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English (en)
French (fr)
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刘新宇
肖斐
程元荣
鲁冠斌
韩硕
陈俊叶
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华为技术有限公司
复旦大学
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Publication of WO2024046395A1 publication Critical patent/WO2024046395A1/zh

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
    • C08G63/68—Polyesters containing atoms other than carbon, hydrogen and oxygen
    • C08G63/685—Polyesters containing atoms other than carbon, hydrogen and oxygen containing nitrogen
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
    • C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D3/00—Electroplating: Baths therefor
    • C25D3/02—Electroplating: Baths therefor from solutions
    • C25D3/12—Electroplating: Baths therefor from solutions of nickel or cobalt
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D3/00—Electroplating: Baths therefor
    • C25D3/02—Electroplating: Baths therefor from solutions
    • C25D3/30—Electroplating: Baths therefor from solutions of tin
    • C25D3/32—Electroplating: Baths therefor from solutions of tin characterised by the organic bath constituents used
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D3/00—Electroplating: Baths therefor
    • C25D3/02—Electroplating: Baths therefor from solutions
    • C25D3/38—Electroplating: Baths therefor from solutions of copper
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D3/00—Electroplating: Baths therefor
    • C25D3/02—Electroplating: Baths therefor from solutions
    • C25D3/46—Electroplating: Baths therefor from solutions of silver
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D3/00—Electroplating: Baths therefor
    • C25D3/02—Electroplating: Baths therefor from solutions
    • C25D3/50—Electroplating: Baths therefor from solutions of platinum group metals
    • C25D3/52—Electroplating: Baths therefor from solutions of platinum group metals characterised by the organic bath constituents used
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D3/00—Electroplating: Baths therefor
    • C25D3/02—Electroplating: Baths therefor from solutions
    • C25D3/56—Electroplating: Baths therefor from solutions of alloys
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/02—Electroplating of selected surface areas
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D7/00—Electroplating characterised by the article coated
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D7/00—Electroplating characterised by the article coated
    • C25D7/12—Semiconductors
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/40—Forming printed elements for providing electric connections to or between printed circuits
    • H05K3/42—Plated through-holes or plated via connections

Definitions

  • the embodiments of the present application relate to the technical field of metal electroplating, and in particular to a leveling agent, composition and application thereof.
  • metallic copper is widely used as an interconnect material in the fields of integrated circuits, electronic packaging, and printed circuit boards due to its good conductivity, ductility and other characteristics.
  • metal copper filling of trenches, through holes, blind holes and other holes of different sizes can be achieved to achieve electrical interconnection of copper lines and inter-layer structures.
  • the thickness difference of the copper layer between the area and the low-density interconnection pattern area forms an uneven copper layer as shown in Figure 2, which has a negative impact on the subsequent chemical mechanical polishing (CMP) process.
  • CMP chemical mechanical polishing
  • embodiments of the present application provide a leveling agent.
  • the electroplating composition using the leveling agent is used for filling interconnect structures in electronic substrates, which can achieve defect-free metal filling of small-sized holes and grooves at different densities.
  • the metal coating obtained in the wiring area has high surface smoothness and low impurity content inside the coating, which can reduce the difficulty of chemical mechanical polishing and improve the reliability of the coating.
  • the first aspect of the embodiment of the present application provides a leveling agent for metal electroplating.
  • the leveling agent is a polypyridine compound, and the polypyridine compound includes a structural unit represented by formula (I) or The protonated product of the structural unit represented by formula (I),
  • R 1 and R 2 are independently substituted or unsubstituted alkylene, substituted or unsubstituted arylene, substituted or unsubstituted arylene alkyl, substituted or unsubstituted alkylene.
  • R 3 is a single bond, substituted or unsubstituted Alkylene group, substituted or unsubstituted arylene group, substituted or unsubstituted arylene alkyl group, substituted or unsubstituted alkylene aryl group, containing ether oxygen atom, ester group and/or imide group Any type of linking group.
  • the leveling agent in the embodiment of the present application is specifically a polypyridine compound containing an ester group.
  • the leveling agent is added to the electroplating composition and used for electroplating metal filling of holes in the semiconductor manufacturing process, which can inhibit the metal from forming to a certain extent. Excessive deposition can prevent smaller-sized holes from being filled in advance while ensuring that the metal in the holes is filled without defects, reduce the thickness difference of electroplated metal layers in wiring areas with different densities, and effectively reduce the platform fluctuations on the coating surface. , to obtain better planarization effect, which is beneficial to the subsequent CMP process; and the resulting coating has low internal impurity content, which can improve the reliability of the coating.
  • the polypyridine compound includes a protonated product of the structural unit represented by formula (I) and a halide ion.
  • the halide ions include any one of fluoride ions, chloride ions, bromide ions and iodide ions.
  • the protonated product of the structural unit represented by formula (I) can be expressed as formula (I-1). It can be understood that each substituent group in formula (I-1) and the corresponding substituent group in formula (I) consistent.
  • the number of carbon atoms of the substituted or unsubstituted alkylene group is 1-30; the number of carbon atoms of the substituted or unsubstituted arylene group is 6- 30.
  • R 1 can be an alkylene group containing one or more ether oxygen atoms, an arylene group containing one or more ether oxygen atoms, or an arylalkyl group containing one or more ether oxygen atoms. , or an alkylaryl group containing one or more ether oxygen atoms.
  • R 1 is a group containing ether oxygen atoms, which can better inhibit excessive metal deposition, reduce the thickness difference of electroplated metal layers in wiring areas with different densities, and obtain better planarization effects.
  • the alkylene group containing ether oxygen atoms is represented by -(R 4 O) x -L-(R 5 O) y -R 5 -, where R 4 and R 5 are the same or different
  • x is an integer greater than or equal to
  • y is an integer greater than or equal to 1
  • L represents a single bond or at least one ether oxygen block.
  • the values of x and y may be 1-300. In some embodiments, the values of x and y may be 1-100, and in some embodiments, the values of x and y may be 1-30.
  • x is equal to 0, L is a single bond, and R 5 is ethylene.
  • R 1 represents -(CH 2 CH 2 O) y -CH 2 CH 2 -;
  • x is equal to 0, L is a single bond, R 5 is isopropylene group, and R 1 is expressed as -(CH 2 CHCH 2 O) y -CH 2 CHCH 2 -;
  • x is An integer greater than or equal to 1, L is a single bond, R 4 is ethylene, R 5 is isopropylene, and R 1 is expressed as -(CH 2 CH 2 O) x -(CH 2 CHCH 2 O) y -CH 2 CHCH 2 -.
  • L is a single bond.
  • L can also be at least one ether oxygen block; for example, in some embodiments, L is an ether oxygen block -(R 6 O) k - ; In some embodiments, L is two ether oxygen blocks -(R 6 O) k -(R 7 O) l -, and k and l are integers greater than or equal to 1.
  • the connecting group containing an ether oxygen atom, an ester group and/or an imide group may specifically be an alkylene group containing an ether oxygen atom, an ester group and/or an imide group, Arylene groups containing ether oxygen atoms, ester groups and/or imide groups, arylene alkyl groups containing ether oxygen atoms, ester groups and/or imide groups, arylene alkyl groups containing ether oxygen atoms, ester groups and/or Imide alkylene aryl group.
  • the second aspect of the embodiments of the present application provides a method for preparing a leveling agent, including:
  • the intermediate is then reacted with the bipyridine structure-containing compound represented by formula (c) at a second temperature to obtain a leveling agent.
  • the leveling agent includes a polypyridine compound, and the polypyridine compound includes the formula The structural unit represented by (I) or the protonated product of the structural unit represented by formula (I), HO-R 1 -OH formula (a)
  • R 1 is a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted arylene alkyl group, a substituted or unsubstituted alkylene aryl group, or Alkylene group containing ether oxygen atom, ester group and/or imide group, arylene group containing ether oxygen atom, ester group and/or imide group, ether oxygen atom, ester group and/or imide group Any one of arylalkyl groups, alkylene aryl groups containing ether oxygen atoms, ester groups and/or imide groups; in formula (b), X 1 and X are the same or different halogen atoms ; R 2 is independently a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted arylene alkyl group,
  • R 1 and R 2 are independently substituted or unsubstituted alkylene, substituted or unsubstituted arylene, substituted or unsubstituted arylene alkyl, substituted or unsubstituted alkylene.
  • R 3 is a single bond, a substituted or unsubstituted aryl group Alkyl group, substituted or unsubstituted arylene group, substituted or unsubstituted arylene alkyl group, substituted or unsubstituted alkylene aryl group, ether-containing oxygen atom, ester group and/or imide group connection any of the groups.
  • R 1 in formula (a) is the same as R 1 in formula ( I )
  • R 2 in formula (b) is the same as R 2 in formula (I)
  • R 2 in formula (c) R 3 is the same as R 3 in formula (I) and will not be described again here.
  • the first temperature is -20°C to 25°C.
  • the second temperature is 25°C to 200°C.
  • the compound with hydroxyl groups at both ends represented by formula (a) may have a structure represented by formula (a-1), formula (a-2), or formula (a-3).
  • Formula ( a-1), formula (a-2), and formula (a-3), m and n are integers greater than or equal to 1.
  • the preparation method of the leveling agent in the embodiment of the present application has a simple process and is suitable for large-scale production.
  • the third aspect of the embodiments of the present application provides a composition, which is an electroplating composition.
  • the electroplating composition includes a metal ion source, and the leveling agent described in the first aspect of the embodiments of the present application or the implementation of the present application.
  • the leveling agent prepared by the preparation method described in the second aspect.
  • the concentration of the leveling agent in the electroplating composition is 1 ppm-100 ppm. Controlling the leveling agent concentration in the electroplating composition within a suitable range is conducive to obtaining a moderate metal deposition speed and better achieving defect-free and high flatness filling of the entire board in small-sized holes, which is conducive to the production of fine circuits and has Conducive to improving the reliability of electronic products.
  • the electroplating composition further includes one or more of an accelerator, an inhibitor, and an inorganic additive.
  • an accelerator an inhibitor
  • an inorganic additive The synergistic cooperation of leveling agents, accelerators, inhibitors, etc. can effectively reduce the surface roughness of the copper layer. It can also achieve uniform surface copper thickness in areas with different wiring densities, and can better realize defect-free small-sized trenches. High flatness of the entire plate filling reduces the technical difficulty of subsequent polishing processes.
  • the accelerator includes sodium 3-mercapto-1-propanesulfonate (MPS), sodium polydisulfidepropanesulfonate (SPS) and N,N-dimethyl-propanedithiopropanesulfonate.
  • MPS sodium 3-mercapto-1-propanesulfonate
  • SPS sodium polydisulfidepropanesulfonate
  • N,N-dimethyl-propanedithiopropanesulfonate N,N-dimethyl-propanedithiopropanesulfonate.
  • DPS sodium polydisulfidepropanesulfonate
  • concentration of the accelerator in the electroplating composition is 1 ppm-50 ppm.
  • the addition of accelerator can have a depolarization effect, accelerate the deposition of metal at the bottom of the trench, and refine the grains of the metal layer.
  • the inhibitor includes polyethylene glycol (PEG), polypropylene glycol (PPG), block copolymer PEO-PPO-PEO, block copolymer PPO-PEO-PPO, EO and PO without One or more of regular copolymers and propylene glycol block polyethers; the concentration of the inhibitor in the electroplating composition is 1-2000 ppm.
  • the addition of inhibitors can inhibit the rapid deposition of surface copper, prevent early sealing of holes and slots, and is also conducive to obtaining thinner surface copper after copper plating is completed.
  • the inorganic additive includes chloride ions, and the concentration of chloride ions in the electroplating composition is 1 ppm-100 ppm.
  • the addition of chloride ions can make the crystallization of the coating dense, fine and not rough.
  • the electroplating composition further includes at least one acid; the at least one acid includes one or more of sulfuric acid and methylsulfonic acid.
  • the concentration of the at least one acid in the electroplating composition is 1g/L-100g/L. Suitable acid system and acid concentration are beneficial to obtain suitable electroplating deposition rate.
  • 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. It can be understood that, depending on which metal layer is pre-deposited, the metal ion source in the electroplating composition accordingly includes a metal ion source corresponding to the metal element in the pre-deposited metal layer.
  • the copper ion source includes one or more of copper sulfate pentahydrate and copper methane sulfonate; in terms of copper ions, the concentration of the copper ion source in the electroplating composition is 1g/L-100g/L. Controlling the copper ion source within a suitable content range is beneficial to balancing the deposition speed and the brightness and flatness of the resulting copper coating.
  • the fourth aspect of the embodiments of the present application provides the application of the leveling agent described in the first aspect or the leveling agent prepared by the preparation method described in the second aspect, or the composition described in the third aspect in electroplating metal.
  • the electroplated metal includes any one of electroplated copper and copper alloy, electroplated nickel and nickel alloy, electroplated tin and tin alloy, electroplated cobalt and cobalt alloy, electroplated ruthenium and ruthenium alloy, electroplated silver and silver alloy. kind.
  • the electroplated metal includes full metal electroplating filling of hole slots on the electronic substrate.
  • the electronic substrate may be an ordinary substrate, a printed circuit board, a packaging substrate, etc.
  • the hole groove may include a trench and/or a via hole, and the via hole may include a through hole, a blind hole, or a buried hole.
  • the electroplated metal includes electroplated metal in the printed circuit board preparation process, electroplated metal in the integrated circuit metal interconnection process, and electroplated metal in the electronic packaging process.
  • the electroplated metal may be electroplated metal in processes including Damascus trench filling, through silicon via filling, substrate rewiring, metal bump deposition, or hole filling.
  • the leveling agent provided by the embodiment of the present application is used for all-metal electroplating filling of hole slots on electronic substrates, which can achieve defect-free filling of nano-scale small-sized holes and slots, and can simultaneously reduce high-density interconnection pattern areas and low-density interconnection pattern areas.
  • the thickness difference of the copper interconnection layer makes the plating surface flatter and more uniform, improves the uniformity of electroplating of the entire electronic substrate, and reduces the difficulty of subsequent CMP processes; it is also conducive to the production of fine circuits, improves the reliability of electronic products, and thus better passes the process A simple and low-cost way to meet the manufacturing needs of high-density interconnected products.
  • the fifth aspect of the embodiment of the present application provides a method of electroplating metal, including the following steps:
  • the substrate to be electroplated is contacted with the composition described in the third aspect of the embodiment of the present application, and current is applied to the substrate to be electroplated to perform electroplating, so that a metal layer is formed on the substrate to be electroplated.
  • the electroplating process conditions are: the electroplating temperature is 10°C-40°C, the current density is 0.5ASD-6ASD, and the electroplating time is 10s-200s.
  • the electroplating includes the first step of electroplating, the second step of electroplating and the third step of electroplating.
  • the current of the first step of electroplating is 0.2ASD-1ASD, and the electroplating time is 1s-15s;
  • the second step of electroplating The current of the electroplating step is 0.8ASD-2ASD, and the electroplating time is 10s-100s;
  • the current of the third electroplating step is 2ASD-6ASD, and the electroplating time is 10s-100s.
  • the substrate to be electroplated is provided with holes and grooves
  • the metal layer includes an in-hole filling layer that fills the holes and grooves and a surface deposition layer deposited around the holes and grooves.
  • the sixth aspect of the present application provides an electronic substrate, including a base layer and a metal layer disposed on the base layer.
  • the metal layer is formed by electroplating the composition described in the third aspect of the embodiment of the present application, or using the fifth aspect. The method described in this aspect is formed.
  • the metal layer includes any one of copper or copper alloy layer, nickel or nickel alloy layer, tin or tin alloy layer, cobalt or cobalt alloy layer, ruthenium or ruthenium alloy layer, silver or silver alloy layer kind.
  • An embodiment of the present application further provides an electronic device, which includes the electronic substrate described in the sixth aspect of the embodiment of the present application.
  • Figure 1a is a schematic diagram of void defects formed by electroplated copper filling holes
  • Figure 1b is a schematic diagram of pore defects formed by electroplating copper filling holes
  • Figure 1c is a schematic diagram of electroplated copper filling holes to form super filling
  • Figure 2 is a schematic diagram of existing electroplated copper filling holes to form an uneven copper layer
  • Figure 3 is a schematic diagram of the formation process of the copper interconnection layer in the semiconductor process
  • Figure 4 is a schematic structural diagram of a substrate with multiple copper interconnect layers
  • Figure 5 is a schematic structural diagram of an electronic substrate 100 provided by an embodiment of the present application.
  • Figures 6a and 6b are cross-sectional electron micrographs of the sample after electroplating in the comparative example;
  • Figure 6b is a partial enlarged view of Figure 6a;
  • Figure 7 is a cross-sectional electron microscope photo of the sample after electroplating in Example 1 of the present application.
  • Figures 8 and 9 are cross-sectional electron micrographs of the sample after electroplating in Example 2 of the present application.
  • FIG. 3 is a schematic diagram of the formation process of the copper interconnection layer in the semiconductor process.
  • 10 a is a patterned substrate.
  • the patterned substrate 10 a includes a base 11 and a patterned dielectric layer 21 .
  • the patterned dielectric layer 21 is provided with a plurality of trenches 2 .
  • the plurality of trenches 2 of the dielectric layer 21 are filled with copper to form a copper layer 22, and the electroplated substrate 10b is obtained.
  • the copper layer 22 includes a filling layer in the holes filled in the trenches 2. and a surface deposition layer covering the surface of the dielectric layer 21 .
  • the dielectric layer 21 and the copper layer 22 together form a copper interconnection layer 20' without CMP treatment.
  • the CMP-processed copper interconnect layer 20 is obtained, that is, the CMP-processed substrate 10c is obtained.
  • the substrate 10c is further prepared with a copper interconnection layer, for example, a copper interconnection layer 30 is formed on the copper interconnection layer 20, thereby obtaining a substrate 10d with multiple copper interconnection layers.
  • the ideal situation is that as shown in Figure 3, the filling layer in the hole in the trench 2 has no voids, pores and other defects; in order to facilitate the CMP process, during the process of electroplating and depositing copper,
  • the ideal situation is that the copper layer 22 is as shown in the electroplated substrate 10b in Figure 3.
  • the thickness difference of the copper interconnection layer in the high-density interconnection pattern area and the low-density interconnection pattern area is small, the entire copper layer 22 surface is relatively flat, and the overall copper layer 22 The thickness is smaller.
  • the current plating solution formula is difficult to form a copper interconnect layer with high surface flatness and no defects, and is prone to defects such as voids and pores as shown in Figure 1a and Figure 1b, or high-density interconnect pattern areas as shown in Figure 2 Problems with large differences in copper interconnect layer thickness in low-density interconnect pattern areas.
  • the high-density interconnection pattern area refers to the area where the interconnection pattern (such as holes and slots) of the interconnection layer has a relatively high density (including the number of holes and slots or the area ratio of all holes and slots), and the low-density interconnection pattern area refers to the area of the interconnection layer.
  • Interconnect graphics (such as slots) set areas of relatively low density.
  • Embodiments of the present application provide a leveling agent that can inhibit metal deposition to a certain extent and facilitate the realization of defect-free filling of small-sized holes (including trenches and via holes) with high flatness.
  • the leveling agent provided by the embodiments of the present application can be added to the electroplating solution as an additive for metal plating.
  • the leveling agent is a polypyridine compound, and the polypyridine compound includes a structural unit represented by formula (I). Or the protonated product of the structural unit represented by formula (I),
  • R 1 and R 2 are independently substituted or unsubstituted alkylene, substituted or unsubstituted arylene, substituted or unsubstituted arylene alkyl, substituted or unsubstituted alkylene.
  • R 3 is a single bond, substituted or unsubstituted Alkylene group, substituted or unsubstituted arylene group, substituted or unsubstituted arylene alkyl group, substituted or unsubstituted alkylene aryl group, containing ether oxygen atom, ester group and/or imide group Any type of linking group.
  • the above-mentioned leveling agent provided in the embodiments of the present application is specifically a polypyridine compound containing an ester group.
  • the leveling agent has a good leveling effect.
  • the leveling agent is added to the electroplating composition and used in the semiconductor manufacturing process.
  • the electroplated metal filling of medium-sized hole slots can inhibit excessive metal deposition to a certain extent. It can prevent smaller-sized holes from being filled in advance and reduce the wiring of different densities while ensuring that the metal in the hole slots is filled without defects.
  • the thickness difference of the regional electroplated metal layer can effectively reduce the plateau undulations on the surface of the plating layer and obtain better planarization effect, which is beneficial to the subsequent CMP process; the molecular structure of the leveler polymer in the embodiment of the present application is stable, which can make the obtained The impurity content inside the coating is low, which improves the reliability of the coating.
  • polypyridine compounds include protonated products of structural units represented by formula (I) and halide ions. That is, polypyridine compounds include structural units represented by formula (II), and halide ions include fluoride ions. , any one of chloride ion, bromide ion and iodide ion.
  • the protonated product of the structural unit represented by formula (I) can be expressed as formula (I-1). It can be understood that each substituent group in formula (I-1) and formula (II) is consistent with the formula (I). The corresponding substituent groups are the same.
  • X - is a halide ion. In some embodiments, the two X -'s in formula (I) are the same halide ions to facilitate the preparation of the leveling agent.
  • the number of carbon atoms of the substituted or unsubstituted alkylene group may be 1-30; in some embodiments, The number of carbon atoms of the substituted or unsubstituted alkylene group can specifically be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 ,19,20,21,22,23,24,25,26,27,28,29,30.
  • R 1 , R 2 , and R 3 may be, for example, substituted or unsubstituted methylene, substituted or unsubstituted ethylene, substituted or unsubstituted propylene, and substituted or unsubstituted isopropylene. , substituted or unsubstituted butylene, substituted or unsubstituted isobutylene, substituted or unsubstituted neopentylene, substituted or unsubstituted hexylene, etc.
  • the number of carbon atoms of the substituted or unsubstituted arylene group may be 6-30; in some embodiments, the number of carbon atoms of the substituted or unsubstituted arylene group may be 6-30.
  • the number specifically can 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, 30.
  • R 1 , R 2 , and R 3 may be, for example, a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenylene group, a substituted or unsubstituted terphenylene group, or a substituted or unsubstituted fluorene group. group, substituted or unsubstituted naphthylene group, substituted or unsubstituted anthracene group, etc.
  • the number of carbon atoms of the substituted or unsubstituted arylene alkyl group may be 7-40; in some embodiments, the number of carbon atoms of the substituted or unsubstituted arylene alkyl group may be 7-40.
  • the number of carbon atoms of the group can specifically be 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, 40.
  • the number of carbon atoms of the substituted or unsubstituted alkylene aryl group may be 7-40; in some embodiments, the number of carbon atoms of the substituted or unsubstituted alkylene aryl group may be 7-40.
  • the number of carbon atoms of the group can specifically be 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, 40.
  • the substituent groups in the substituted alkylene group, substituted arylene group, substituted arylene alkyl group and substituted alkylene aryl group may be It is not limited to halogen atoms.
  • the number of carbon atoms of the alkylene group containing ether oxygen atom, ester group and/or imide group can be 2-30, and the number 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, 30;
  • the carbon number of the arylene group containing ether oxygen atom, ester group and/or imide group can be 6-30, and the number 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, 29, 30; containing ether oxygen atoms, ester groups and/or imide groups
  • the number of carbon atoms of the arylene alkyl group can be 7-40, and the number of carbon atoms is specifically 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, 40;
  • Alkylene groups containing ether oxygen atoms, ester groups and/or imide groups are alkylene groups containing any one or more of ether oxygen atoms, ester groups, and imide groups; alkylene groups containing ether oxygen atoms, ester groups An arylene group containing any one or more of ether oxygen atoms, ester groups, and imide groups; and/or an arylene group containing an ether oxygen atom, an ester group, and/or an imide group
  • the arylene alkyl group is an arylene alkyl group containing any one or more of ether oxygen atoms, ester groups, and imide groups; an alkylene group containing ether oxygen atoms, ester groups, and/or imide groups
  • An alkylene aryl group is an alkylene aryl group containing any one or more of ether oxygen atoms, ester groups, and imide groups.
  • R 1 can be an alkylene group containing one or more ether oxygen atoms, an arylene group containing one or more ether oxygen atoms, or an arylalkyl group containing one or more ether oxygen atoms. , or an alkylaryl group containing one or more ether oxygen atoms.
  • R 1 is a group containing ether oxygen atoms, which can better inhibit excessive metal deposition, reduce the thickness difference of electroplated metal layers in wiring areas with different densities, and obtain better planarization effects.
  • R 1 can be an alkylene group containing ether oxygen atoms
  • the alkylene group containing ether oxygen atoms can be expressed as -(R 4 O) x -L-(R 5 O) y -R 5 -, where R 4 and R 5 can be the same or different alkylene groups, 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.
  • R 4 and R 5 may specifically be an alkylene group having 2 to 10 carbon atoms, such as an ethylene group, a propylene group, an isopropylene group, etc.
  • the values of x and y can be 1-300.
  • the values of x and y may be 1-100. In some embodiments, the values of x and y may be 1-30. 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, 30.
  • x is equal to 0, L is a single bond, and R 5 is ethylene.
  • R 1 represents -(CH 2 CH 2 O) y -CH 2 CH 2 -;
  • x is equal to 0, L is a single bond, R 5 is isopropylene group, and R 1 is expressed as -(CH 2 CHCH 2 O) y -CH 2 CHCH 2 -;
  • x is An integer greater than or equal to 1, L is a single bond, R 4 is ethylene, R 5 is isopropylene, and R 1 is expressed as -(CH 2 CH 2 O) x -(CH 2 CHCH 2 O) y -CH 2 CHCH 2 -.
  • L is a single bond.
  • L can also be at least one ether oxygen block; for example, in some embodiments, L is an ether oxygen block -(R 6 O) k - ; In some embodiments, L is two ether oxygen blocks -(R 6 O) k -(R 7 O) l -, and k and l are integers greater than or equal to 1.
  • the connecting group containing ether oxygen atom, ester group and/or imide group can specifically contain ether oxygen atom, ester group and/or imide group alkylene group, arylene group containing ether oxygen atom, ester group and/or imide group, arylene alkane containing ether oxygen atom, ester group and/or imide group group, an alkylene aryl group containing an ether oxygen atom, an ester group and/or an imide group.
  • the polypyridine compound only contains the protonated product of the structural unit represented by formula (I) and halide ions, and the polypyridine compound is expressed as a polypyridine salt compound represented by formula (1):
  • n is an integer greater than or equal to 2.
  • n may be, for example, an integer from 2 to 15.
  • n may be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15.
  • the embodiments of the present application also provide a method for preparing a leveling agent, including:
  • Step S101 react the compound with hydroxyl groups at both ends represented by formula (a) and the compound containing an acid halide group represented by formula (b) at a first temperature to obtain an intermediate;
  • Step S102 react the obtained intermediate with the bipyridine structure-containing compound represented by formula (c) at a second temperature to obtain a leveling agent.
  • the leveling agent includes a polypyridine compound, and the polypyridine compound includes the formula (I) The structural unit shown or the protonation product of the structural unit shown in formula (I), HO-R 1 -OH formula (a)
  • R 1 is a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted arylene alkyl group, a substituted or unsubstituted alkylene aryl group, or Alkylene group containing ether oxygen atom, ester group and/or imide group, arylene group containing ether oxygen atom, ester group and/or imide group, ether oxygen atom, ester group and/or imide group Any one of arylene alkyl groups, alkylene aryl groups containing ether oxygen atoms, ester groups and/or imide groups; in formula (b), X 1 and X are the same or different halogens Atom; R 2 is substituted or unsubstituted alkylene, substituted or unsubstituted arylene, substituted or unsubstituted arylene alkyl, substituted or unsubstituted alkylene
  • R 1 and R 2 are independently substituted or unsubstituted alkylene, substituted or unsubstituted arylene, substituted or unsubstituted arylene alkyl, substituted or unsubstituted alkylene.
  • R 3 is a single bond, substituted or unsubstituted Alkylene group, substituted or unsubstituted arylene group, substituted or unsubstituted arylene alkyl group, substituted or unsubstituted alkylene aryl group, containing ether oxygen atom, ester group and/or imide group Any type of linking group.
  • R 1 in formula (a) is the same as R 1 in formula ( I )
  • R 2 in formula (b) is the same as R 2 in formula (I)
  • R 2 in formula (c) R 3 is the same as R 3 in formula (I) and will not be described again here.
  • the polypyridine compound includes a structural unit represented by formula (II), and X- is a halide ion.
  • X in formula (II) is derived from the halogen atom X in formula (b).
  • the compound with hydroxyl groups at both ends represented by formula (a) may have a structure represented by formula (a-1), formula (a-2), or formula (a-3).
  • Formula ( a-1), formula (a-2), and formula (a-3), m and n are integers greater than or equal to 1, for example, they can be 1-300; in some embodiments, the values of m and n can be is 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 ,26,27,28,29,30.
  • the first temperature in step S101, may be -20°C to 25°C; in some embodiments, the first temperature may be 0°C to 10°C.
  • methylene chloride or the like can be used as a solvent.
  • the second temperature in step S102, may be 25°C to 200°C; in some embodiments, the second temperature may be 50°C to 150°C.
  • the polypyridine compounds prepared in the examples of this application are solid matter.
  • An embodiment of the present application also provides an electroplating composition, which includes a metal ion source and the leveling agent described above in the embodiment of the present application.
  • the electroplating composition can be used as an electroplating solution for electroplating and depositing metal layers.
  • the concentration of the leveling agent in the electroplating composition is 1 ppm-100 ppm. In some embodiments, the concentration of the leveling agent is 2 ppm-80 ppm; in some embodiments, the concentration of the leveling agent is 5 ppm-50 ppm. In some embodiments, the leveler concentration is 10 ppm-30 ppm. Specifically, 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 leveling agent concentration in the electroplating composition within a suitable range is conducive to obtaining a moderate metal deposition speed and better achieving defect-free and high flatness filling of the entire board in small-sized holes, which is conducive to the production of fine circuits and has Conducive to improving the reliability of electronic products.
  • the electroplating composition further includes one or more of an accelerator, an inhibitor, and an inorganic additive.
  • an accelerator an inhibitor
  • an inorganic additive The synergistic cooperation of leveling agents, accelerators, inhibitors, etc. can effectively reduce the surface roughness of the copper layer, and achieve uniform surface copper thickness in areas with different wiring densities, which can better achieve defect-free small-sized holes and slots. High flatness of the entire plate filling reduces the technical difficulty of subsequent polishing processes.
  • the accelerator includes sodium 3-mercapto-1-propanesulfonate (MPS), sodium polydisulfidepropanesulfonate (SPS) and N,N-dimethyl-dithiocarboxamidepropanesulfonic acid One or more of sodium (DPS).
  • MPS sodium 3-mercapto-1-propanesulfonate
  • SPS sodium polydisulfidepropanesulfonate
  • DPS N,N-dimethyl-dithiocarboxamidepropanesulfonic acid
  • DPS sodium 3-mercapto-1-propanesulfonate
  • SPS sodium polydisulfidepropanesulfonate
  • DPS N,N-dimethyl-dithiocarboxamidepropanesulfonic acid
  • DPS sodium 3-mercapto-1-propanesulfonate
  • SPS sodium polydisulfidepropanesulfonate
  • DPS N,N-dimethyl-dithiocarboxamidepropanesul
  • the inhibitors include polyethylene glycol (PEG), polypropylene glycol (PPG), and 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 polyoxypropane (PO), propylene glycol embedded One or more segmented polyethers.
  • PEG polyethylene glycol
  • PPG polypropylene glycol
  • PEO-PPO-PEO polyethylene oxide-polypropylene oxide-polyethylene oxide
  • block copolymer PPO-PEO-PPO polypropylene oxide-polyethylene oxide-polypropylene oxide
  • EO polyoxyethylene
  • PO polyoxypropane
  • the concentration of the inhibitor in the electroplating composition may be 1 ppm to 2000 ppm. In some embodiments, the inhibitor is present in the electroplating composition at a concentration of 10 ppm to 1000 ppm. In some embodiments, the inhibitor is present in the electroplating composition at a concentration of 100 ppm to 1000 ppm. In some embodiments, the inhibitor is present in the electroplating composition at a concentration of 150 ppm to 500 ppm.
  • the inorganic additive includes chloride ions, and the concentration of chloride ions in the electroplating composition is 1 ppm-100 ppm.
  • 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, 60ppm, 70ppm, 80ppm, 90ppm, 100ppm.
  • the addition of chloride ions can make the crystallization of the coating dense, fine and not rough.
  • the electroplating composition further includes at least one acid; the at least one acid includes one or more of sulfuric acid and methylsulfonic acid.
  • the concentration of at least one acid in the electroplating composition is 1g/L-100g/L.
  • the concentration of at least one acid in the electroplating composition may 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, L, 70g/L, 80g/L, 90g/L, 100g/L.
  • Suitable acid system and acid concentration are beneficial to obtain suitable electroplating deposition rate.
  • 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. It can be understood that, depending on which metal layer is pre-deposited, the metal ion source in the electroplating composition accordingly includes a metal ion source corresponding to the metal element in the pre-deposited metal layer. For example, if a metal copper layer is pre-deposited, the metal ion source includes a copper ion source.
  • the copper ion source includes one or more of copper sulfate pentahydrate and copper methane sulfonate.
  • the acid system of the above-mentioned copper ion source for electroplating has high current efficiency, is environmentally friendly, and can better fill blind holes through the combination of various additives.
  • the concentration of the copper ion source in the electroplating composition is 1g/L-100g/L in terms of copper ions.
  • the concentration of the copper ion source in the electroplating composition can be, for example, 1g/L, 10g/L, 20g/L, 30/L, 40g/L, 50g/L, 60g/L. L, 70g/L, 80g/L, 90g/L, 100g/L. Controlling the copper ion source within a suitable content range is beneficial to balancing the deposition speed and the brightness and flatness of the resulting copper coating.
  • the new leveling agent provided in the embodiments of this application is applied to metal plating liquids such as copper plating liquid.
  • metal plating liquids such as copper plating liquid.
  • the leveling agent operating window of the embodiment of the present application is wide.
  • electroplating holes with a hole size between 28 nm and 1.2 ⁇ m it can complete void-free filling of holes of all sizes, which is conducive to improving the final product. reliability.
  • the embodiments of the present application also provide the application of the above-mentioned leveling agent and/or electroplating composition in the metal electroplating process.
  • 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, electroplated silver and silver alloys. .
  • electroplated metal includes electroplated metal in the printed circuit board preparation process, electroplated metal in the integrated circuit metal interconnection process, or electroplated metal in the electronic packaging process.
  • the electroplated metal may be electroplated metal in processes including Damascus trench filling, through silicon via filling, substrate rewiring, metal bump deposition, or via hole filling.
  • metal plating includes full metal electroplating filling of hole slots on the electronic substrate.
  • the electronic substrate may be an ordinary substrate, a printed circuit board, a packaging substrate, etc.
  • the hole groove may include a trench and/or a via hole, and the via hole may include a through hole, a blind hole, or a buried hole.
  • Full metal filling can be electroplated copper and copper alloy, electroplated nickel and nickel alloy, electroplated tin and tin alloy, electroplated cobalt and cobalt alloy, electroplated ruthenium and ruthenium alloy, or electroplated silver and silver alloy filling.
  • the leveling agent provided by the embodiment of the present application is used for all-metal electroplating filling of hole slots on electronic substrates, which can achieve defect-free filling of nano-scale small-sized holes and slots, and can simultaneously reduce high-density interconnection pattern areas and low-density interconnection pattern areas.
  • the thickness difference of the copper interconnection layer makes the plating surface flatter and more uniform, improves the uniformity of electroplating of the entire electronic substrate, and reduces the difficulty of subsequent CMP processes; it is also conducive to the production of fine circuits, improves the reliability of electronic products, and thus better passes the process A simple and low-cost way to meet the manufacturing needs of high-density interconnected products.
  • Embodiments of the present application also provide a method for electroplating metal, including the following steps:
  • the substrate to be electroplated is brought into contact with the electroplating composition described in the embodiments of the present application, and current is applied to the substrate to be electroplated to perform electroplating, so that a metal layer is formed on the substrate to be electroplated.
  • the substrate to be electroplated can be immersed in the electroplating composition as a cathode, and the electroplating composition, that is, the electroplating solution, serves as the electrolyte and forms a conductive loop together with the soluble or insoluble anode, thereby realizing metal deposition on the substrate to be electroplated.
  • the electroplating composition that is, the electroplating solution
  • holes are provided on the substrate to be electroplated, and the metal layer includes an in-hole filling layer that fills the holes and a surface deposition layer deposited around the holes.
  • the via slot includes a trench and/or a via hole, and the via hole may include one or more of a through hole, a blind hole, and a buried hole.
  • the lateral size of the hole groove may be 28 nm-1.2 ⁇ m, and the depth may be 100 nm-300 nm.
  • the lateral size of the hole groove can be, for example, 28nm, 30nm, 35nm, 40nm, 45nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1.0 ⁇ m, 1.1 ⁇ m, 1.2 ⁇ m.
  • the depth may be, for example, 100 nm, 200 nm, or 300 nm.
  • the substrate to be electroplated may have holes with different lateral dimensions and depths. Among them, the lateral size of the trench refers to the width of the trench, and the lateral size of the via hole refers to the diameter of the through hole.
  • the substrate to be electroplated may be provided with areas with different hole and groove distribution densities, such as a high-density hole and groove distribution area and a low-density hole and groove distribution area.
  • the inner wall of the hole is metallized, for example, a metal seed layer, such as a copper seed layer, is chemically plated on the inner wall of the hole.
  • a metal seed layer such as a copper seed layer
  • the electroplating process conditions are: the electroplating temperature is 10°C-40°C, the current density is 0.5ASD-6ASD, during electroplating The time is 10s-200s.
  • the electroplating includes the first step of electroplating, the second step of electroplating and the third step of electroplating.
  • the current of the first step of electroplating is 0.2ASD-1ASD, and the electroplating time is 1s-15s; the second step of electroplating
  • the current of the electroplating step is 0.8ASD-2ASD, and the electroplating time is 10s-100s;
  • the current of the third electroplating step is 2ASD-6ASD, and the electroplating time is 10s-100s.
  • defect-free filling can be better obtained through step-by-step electroplating, and a suitable surface metal layer thickness can be obtained.
  • the first step of electroplating can better repair the copper seed layer; the second step of electroplating can better achieve pore filling; and the third step of electroplating can thicken the surface to facilitate subsequent polishing and grinding.
  • an embodiment of the present application also provides an electronic substrate 100, including a base layer 101 and a metal layer 102 disposed on the base layer.
  • the metal layer 102 is formed by electroplating with the electroplating composition described above in the embodiment of the present application, or by using the present invention.
  • the application embodiment is formed by the method of electroplating metal described above.
  • the metal layer 102 includes any one of copper or copper alloy layer, nickel or nickel alloy layer, tin or tin alloy layer, cobalt or cobalt alloy layer, ruthenium or ruthenium alloy layer, silver or silver alloy layer. .
  • the base layer 101 includes a substrate 1011 and a dielectric layer 1012.
  • the base layer 101 is provided with a hole 103.
  • the metal layer 102 includes an in-hole filling layer 1021 that fills the hole 103 and a layer deposited around the hole 103.
  • Layer 1022 is deposited on the surface. It can be understood that in some embodiments, after the surface deposition layer 1022 is removed by the CMP process, the metal layer 102 only includes the in-hole filling layer 1021 that fills the hole trench 103.
  • a metal seed layer such as a copper seed layer, formed by metallizing the hole groove 103 may also be located between the base layer 101 and the metal layer 102 .
  • the lateral size of the hole groove 103 may be 28 nm-1.2 ⁇ m, and the depth may be 100 nm-300 nm.
  • a plurality of holes 103 may be provided on the base layer 101, and the plurality of holes 103 may have different lateral dimensions and depths, or may have the same lateral dimensions and depths.
  • the thickness of the surface deposition layer 1022 is less than 8 ⁇ m.
  • the ratio of the average thickness H1 of the surface deposition layer 1022 in the high-density interconnection pattern area to the average thickness H2 of the surface deposition layer 1022 in the low-density interconnection pattern area is less than or equal to 1.7.
  • the ratio of H1 to H2 is less than or equal to 1.5.
  • the ratio of H1 to H2 is less than or equal to 1.3.
  • the ratio of H1 to H2 is less than or equal to 1.1.
  • the electronic substrate 100 shown in FIG. 5 is a schematic structural diagram that has not been processed by CMP.
  • the surface deposition layer 1022 will be removed through a polishing process.
  • An embodiment of the present application also provides an electronic device.
  • the electronic device adopts the electronic substrate 100 described in the embodiment of the present application.
  • R 1 is R 2 is R 3 is a single bond
  • X - is Cl -
  • n is 4, and * indicates the connection position.
  • polypyridine compound A The preparation method of polypyridine compound A is as follows:
  • a copper electroplating solution includes components in the following mass proportions:
  • Copper sulfate pentahydrate (calculated as copper ions): 50g/L
  • Inhibitor L64 (propylene glycol block polyether): 300 ppm.
  • 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 Example 1 is that polypyridine compound A is not added.
  • the copper electroplating solution of Example 1 and the copper electroplating solution of the comparative example were respectively used to perform electroplating copper filling on the substrate to be plated with a trench structure with a diameter of 60nm to 120nm and a depth of 120nm to 250nm.
  • the substrate to be electroplated was equipped with PVD copper
  • the electroplating temperature is normal temperature electroplating.
  • the electroplating process adopts a three-step current method.
  • the first step has a current of 0.65ASD and a plating time of 6 seconds.
  • the second step has a current of 1ASD and a plating time of 40 seconds.
  • the third step The current is 6ASD and the plating time is 45 seconds.
  • Figures 6a and 6b are cross-sectional electron micrographs of the sample after electroplating in the comparative example; Figure 6b is a partial enlarged view of Figure 6a. It can be seen from Figure 6a and Figure 6b that without adding leveling agent, the surface of the copper layer in the high-density trench area and the low-density trench area is extremely undulating. The average thickness ratio of the copper layer is as high as 1.806, making it difficult to perform subsequent CMP operations.
  • Figure 7 is a cross-sectional electron microscope photograph of the sample after electroplating in Example 1 of the present application. It can be seen from Figure 7 that when polypyridine compound A leveling agent is added, the copper layer surface undulations in the high-density trench area and low-density trench area are smaller, and the high-density trench area and low-density trench area have smaller surface fluctuations. The average thickness ratio of the copper layer in the area is only 1.023, and the flatness is greatly improved, which can greatly reduce the burden of the subsequent CMP polishing process. In addition, it can also be seen from Figure 7 that the plating solution added with polypyridine compound A leveler achieves defect-free filling of small-sized trenches, as well as high-flatness simultaneous filling of different sizes and different wiring densities.
  • R 1 is R 2 is
  • R 3 is X - is Cl - , n is 4, * indicates the connection position.
  • polypyridine compound B The preparation method of polypyridine compound B is as follows:
  • a copper electroplating solution includes components in the following mass proportions:
  • Copper sulfate pentahydrate (calculated as copper ions): 50g/L
  • Inhibitor L65 (propylene glycol block polyether): 150 ppm.
  • the copper electroplating solution of Example 2 was used to perform electroplating copper filling on the substrate to be electroplated with a trench structure with a diameter of 40 to 120 nm and a depth of 100 to 250 nm.
  • the substrate to be electroplated was a pattern piece with a PVD copper seed layer, and the electroplating temperature was Normal temperature electroplating, the electroplating process adopts a three-step current method, the first step current is 0.65ASD, the plating time is 6 seconds, the second step current is 1ASD, the plating time is 40 seconds, the third step current is 6ASD, the plating time is 45 seconds .
  • Figures 8 and 9 are cross-sectional electron micrographs of the sample after electroplating in Example 2 of the present application. It can be seen from Figure 8 and Figure 9 that when polypyridine compound B leveling agent is added, the copper layer surface undulations in the high-density trench area and low-density trench area are smaller, and the high-density trench area and low-density trench area have smaller surface fluctuations. The average thickness ratio of the copper layer in the density trench area is only 1.0, and the flatness is greatly improved, which can greatly reduce the burden of the subsequent CMP polishing process. It can also be seen from Figures 8 and 9 that the plating solution added with polypyridine compound A leveling agent achieves defect-free filling of small-sized trenches, as well as high-flatness simultaneous filling of different sizes and different wiring densities.
  • the new leveling agent of the embodiment of the present application is added to the electroplating composition and used for electroplating copper filling, which can ensure pore-free filling and leveling of metal copper in trenches of different sizes at the nanometer, submicron and submicron levels.
  • the agent will ultimately achieve a better flattening effect by inhibiting excessive copper deposition, ensuring that smaller-sized graphics will not be filled in advance, effectively reducing the undulations of the plating surface platform, thereby obtaining a uniform copper thickness and a smooth board appearance.
  • Good samples reduce the difficulty of subsequent polishing processes and improve the reliability of the final product.
  • At least one refers to one or more
  • plural refers to two or more.
  • At least one of the following” or similar expressions thereof refers to any combination of these items, including any combination of a single item (items) or a plurality of items (items).
  • at least one of a, b, or c or “at least one of a, b, and c” can mean: a, b, c, a-b ( That is, a and b), a-c, b-c, or a-b-c, where a, b, and c can be single or multiple respectively.
  • the size of the sequence numbers of the above-mentioned processes does not mean the order of execution. Some or all steps can be executed in parallel or one after another. The execution order of each process should be based on its function and order. The internal logic is determined and should not constitute any limitation on the implementation process of the embodiments of the present application.

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Abstract

本申请实施例提供一种整平剂，具体为聚吡啶类化合物，聚吡啶类化合物包括式(I)所示的结构单元或式(I)所示结构单元的质子化产物，式(I)中，R1、R2独立地为取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的亚烷基、亚芳基、亚芳基烷基、亚烷基芳基中的任意一种；R3为单键、取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基等基团。该整平剂有利于获得无缺陷高平整度填充。本申请实施例还提供了整平剂的制备方法及其应用。

Description

一种整平剂、组合物及其应用
本申请要求于2022年8月31日提交中国专利局、申请号为202211056293.6、申请名称为“一种整平剂、组合物及其应用”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请实施例涉及电镀金属技术领域，特别是涉及一种整平剂、组合物及其应用。
背景技术
在电子行业制造工艺中，金属铜由于具有良好的导电性、延展性等特点，作为互联材料被广泛应用于集成电路、电子封装和印制电路板等领域。通过电镀工艺完成对不同尺寸沟槽、通孔或盲孔等孔槽的金属铜填充，可以实现铜线路和层间结构的电气互联。
然而在电镀铜填充孔槽的过程中，电流在孔内外分布不均以及孔口处尖端产生放电效应，使得孔内外铜沉积的速率不同，容易导致电镀铜层提前封口，在内部产生空洞(如图1a所示)和孔隙(如图1b所示)缺陷,从而影响互联结构的可靠性。为改善上述缺陷的产生，一般通过在电镀液中加入适当的添加剂，以改变电极表面的极化电位，调控孔内外不同区域铜沉积的速率，达成孔槽电镀铜填充时“孔底加速，孔口抑制”的效果，最终实现无缺陷超填充(如图1c所示)。但是，在孔槽实现超填充后会在图形顶部持续铜沉积，出现图1a、图1b及图1c中所示的顶部凸点缺陷，这样对于整板孔槽填充则会增大高密度互联图形区域与低密度互联图形区域铜层的厚度差异，形成如图2所示的不平坦的铜层，从而对后续的化学机械抛光(CMP)环节造成不良影响。而且随着集成电路工艺特征尺寸的不断减小，获得无缺陷高平整度的电镀互联层的难度越来越高，对填充小尺寸沟槽所用电镀液配方的要求也越来越严格。因此有必要提供一种可以在一定程度上抑制铜的沉积，有利于实现无缺陷填充，同时能使镀层表面趋于平坦均匀，减小高密度互联图形区域与低密度互联图形区域铜层的厚度差异，使得后续CMP工艺易于进行的添加剂，以实现表面平整度高的无缺陷填充。
发明内容
鉴于此，本申请实施例提供一种整平剂，使用该整平剂的电镀组合物用于电子基板中互联结构的填充，可以实现小尺寸孔槽的无缺陷金属填充，且在不同密度的布线区域得到的金属镀层表面平整度高，镀层内部杂质含量低，从而可降低化学机械抛光难度，提高镀层可靠性。
具体地，本申请实施例第一方面提供一种整平剂，用于金属电镀，所述整平剂为聚吡啶类化合物，所述聚吡啶类化合物包括式(I)所示的结构单元或式(I)所示结构单元的质子化产物，
式(I)中，R1、R2独立地为取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的亚烷基、含醚氧原子、酯基和/或酰亚胺基的亚芳基、含醚氧原子、酯基和/或酰亚胺基的亚芳基烷基、含醚氧原子、酯基和/或酰亚胺基的亚烷基芳基中的任意一种；R3为单键、取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的连接基团中的任意一种。本申请实施例的整平剂具体为含酯基的聚吡啶类化合物，该整平剂加入到电镀组合物中，用于半导体制造工艺中孔槽的电镀金属填充，可以一定程度地抑制金属的过度沉积，可在保证孔槽内金属无缺陷填充的情况下，避免较小尺寸的孔槽被提前填满，减小不同密度的布线区域电镀金属层的厚度差异，有效降低镀层表面的平台起伏，获得更好的平坦化效果，从而有利于后续CMP工艺的进行；而且所得镀层内部杂质含量低，可提高镀层可靠性。
本申请实施方式中，聚吡啶类化合物包括式(I)所示结构单元的质子化产物和卤素离子。本申请实施 方式中，所述卤素离子包括氟离子、氯离子、溴离子和碘离子中的任意一种。式(I)所示结构单元的质子化产物可以表示为式(I-1)，可以理解地，式(I-1)中的各取代基团与式(I)中的相对应取代基团一致。
本申请实施方式中，所述R1、R2、R3中，取代或非取代的亚烷基的碳原子数为1-30；取代或非取代的亚芳基的碳原子数为6-30。
本申请一些实施方式中，R1可以是含一个或多个醚氧原子的亚烷基、含一个或多个醚氧原子的亚芳基、含一个或多个醚氧原子的芳基烷基、或者含一个或多个醚氧原子的烷基芳基。R1为含醚氧原子的基团可以更好地起到抑制金属过度沉积的效果，减小不同密度的布线区域电镀金属层的厚度差异，获得更好的平坦化效果。
本申请实施方式中，所述含醚氧原子的亚烷基表示为-(R4O)x-L-(R5O)y-R5-，其中，R4、R5为相同或不同的亚烷基，x为大于或等于0的整数，y为大于或等于1的整数，L表示单键或至少一个醚氧嵌段。
本申请实施方式中，x、y的取值可以是1-300。一些实施例中，x、y的取值可以是1-100，一些实施例中，x、y的取值可以是1-30。R1链越长，对电镀金属的抑制效果越强，在相对更高密度布线区的整平性会变好。因此，本申请实施例可以根据应用场景中的布线密度来选择不同的R1链长。
本申请一实施方式中，x等于0，L为单键，R5为亚乙基，此时R1表示为-(CH2CH2O)y-CH2CH2-；本申请一实施方式中，x等于0，L为单键，R5为亚异丙基，此时R1表示为-(CH2CHCH2O)y-CH2CHCH2-；本申请一实施方式中，x为大于或等于1的整数，L为单键，R4为亚乙基，R5为亚异丙基，此时R1表示为-(CH2CH2O)x-(CH2CHCH2O)y-CH2CHCH2-。上述实施例中，L均为单键，本申请一些实施例中，L还可以是至少一个醚氧嵌段；例如一些实施例中，L为一个醚氧嵌段-(R6O)k-；一些实施例中，L为两个醚氧嵌段-(R6O)k-(R7O)l-，k、l为大于或等于1的整数。
本申请实施方式中，R3中，含醚氧原子、酯基和/或酰亚胺基的连接基团具体可以是含醚氧原子、酯基和/或酰亚胺基的亚烷基、含醚氧原子、酯基和/或酰亚胺基的亚芳基、含醚氧原子、酯基和/或酰亚胺基的亚芳基烷基、含醚氧原子、酯基和/或酰亚胺基的亚烷基芳基。
本申请实施例第二方面提供一种整平剂的制备方法，包括：
将式(a)所示的两端带羟基的化合物与式(b)所示的含酰卤基团的化合物在第一温度下反应得到中间体；
再将所述中间体与式(c)所示的含双吡啶结构的化合物在第二温度下反应得到整平剂，所述整平剂包括聚吡啶类化合物，所述聚吡啶类化合物包括式(I)所示的结构单元或式(I)所示结构单元的质子化产物，
HO-R1-OH式(a)
式(a)中，R1为取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的亚烷基、含醚氧原子、酯基和/或酰亚胺基的亚芳基、含醚氧原子、酯基和/或酰亚胺基的芳基烷基、含醚氧原子、酯基和/或酰亚胺基的亚烷基芳基中的任意一种；式(b)中，X1和X为相同或不同的卤素原子；R2独立地为取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的亚烷基、含醚氧原子、酯基和/或酰亚胺基的亚芳基、含醚氧原子、酯基和/或酰亚胺基的芳基烷基、含醚氧原子、酯基和/或酰亚胺基的亚烷基芳基中的任意一种；式(c)中，R3为单键、取代或非取代的亚 烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的连接基团中的任意一种；
式(I)中，R1、R2独立地为取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的亚烷基、含醚氧原子、酯基和/或酰亚胺基的亚芳基、含醚氧原子、酯基和/或酰亚胺基的芳基烷基、含醚氧原子、酯基和/或酰亚胺基的亚烷基芳基中的任意一种；R3为单键、取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的连接基团中的任意一种。
由上述反应过程可知，式(a)中的R1与式(I)中的R1相同，式(b)中的R2与式(I)中的R2相同，式(c)中的R3与式(I)中的R3相同，此处不再赘述。
本申请实施方式中，所述第一温度为-20℃至25℃。
本申请实施方式中，所述第二温度为25℃至200℃。
本申请一些实施方式中，式(a)所示的两端带羟基的化合物可以是具有式(a-1)、式(a-2)、式(a-3)所示的结构，式(a-1)、式(a-2)、式(a-3)中m、n为大于或等于1的整数。
本申请实施例的整平剂的制备方法，工艺简单，适于规模化生产。
本申请实施例第三方面提供一种组合物，所述组合物为电镀组合物，所述电镀组合物包括金属离子源，以及本申请实施例第一方面所述的整平剂或本申请实施例第二方面所述的制备方法制得的整平剂。
本申请实施方式中，所述电镀组合物中，所述整平剂的浓度为1ppm-100ppm。控制电镀组合物中的整平剂浓度在适合范围，有利于获得适中的金属沉积速度，更好地实现小尺寸孔槽无缺陷高平整度的整板填充，从而有利于精细线路的制作，有利于提升电子产品的可靠性。
本申请实施方式中，所述电镀组合物还包括加速剂、抑制剂、无机添加剂中的一种或多种。整平剂与加速剂、抑制剂等的相互协同配合，可以有效降低铜层表面粗糙度，在布线密度不同的区域也可实现表面面铜厚度均匀，可以更好地实现小尺寸沟槽无缺陷高平整度的整板填充，降低后续抛光工艺的技术难度。
本申请实施方式中，所述加速剂包括3-巯基-1-丙烷磺酸钠(MPS)、聚二硫二丙烷磺酸钠(SPS)和N,N-二甲基-二硫甲酰胺丙磺酸钠(DPS)中的一种或多种；所述加速剂在所述电镀组合物中的浓度为1ppm-50ppm。加速剂的加入可以起到去极化效果加速沟槽底部金属的沉积，以及细化金属层的晶粒的作用。
本申请实施方式中，所述抑制剂包括聚乙二醇(PEG)、聚丙二醇(PPG)、嵌段共聚物PEO-PPO-PEO、嵌段共聚物PPO-PEO-PPO、EO与PO的无规共聚物、丙二醇嵌段聚醚中的一种或多种；所述抑制剂在所述电镀组合物中的浓度为1-2000ppm。抑制剂的加入可以抑制表面铜的过快沉积，防止孔槽的提前封口，也有利于在完成镀铜后获得较薄的表面铜。
本申请实施方式中，所述无机添加剂包括氯离子，氯离子在所述电镀组合物中的浓度为1ppm-100ppm。氯离子的加入可以使镀层结晶致密、精细不粗糙。
本申请实施方式中，所述电镀组合物还包括至少一种酸；所述至少一种酸包括硫酸和甲基磺酸中的一种或多种。
本申请实施方式中，所述至少一种酸在所述电镀组合物中的浓度为1g/L-100g/L。适合的酸体系和酸浓度有利于获得适合的电镀沉积速率。
本申请实施方式中，所述金属离子源包括铜离子源、镍离子源、锡离子源、钴离子源、钌离子源、银离子源中的任意一种。可以理解地，预沉积哪种金属层，则电镀组合物中的金属离子源相应地包括预沉积的金属层中金属元素对应的金属离子源。
本申请实施方式中，所述铜离子源包括五水硫酸铜和甲基磺酸铜中的一种或多种；以铜离子计，所述铜离子源在所述电镀组合物中的浓度为1g/L-100g/L。将铜离子源控制在适合的含量范围，有利于兼顾沉积速度以及所得铜镀层的光亮度和平整度。
本申请实施例第四方面提供第一方面所述的整平剂或第二方面所述的制备方法制得的整平剂，或第三方面所述的组合物在电镀金属中的应用。
本申请实施方式中，所述电镀金属包括电镀铜及铜合金、电镀镍及镍合金、电镀锡及锡合金、电镀钴及钴合金、电镀钌及钌合金、电镀银及银合金中的任意一种。
本申请实施方式中，所述电镀金属包括电子基板上孔槽的全金属电镀填充。电子基板可以是普通基板、印制电路板、封装基板等，孔槽包括沟槽和/或导通孔，导通孔可以是包括通孔、盲孔和埋孔。
本申请实施方式中，所述电镀金属包括印刷电路板制备工艺中电镀金属、集成电路金属互联工艺中电镀金属、电子封装工艺中电镀金属。具体地，电镀金属可以是包括大马士革沟槽填充、硅通孔填充、基板再布线、金属凸点沉积、或孔槽填充等工艺中的电镀金属。
本申请实施例提供的整平剂用于电子基板上孔槽的全金属电镀填充，可实现纳米级小尺寸孔槽的无缺陷填充，同时能够减小高密度互联图形区域与低密度互联图形区域铜互联层的厚度差异，使镀层表面更加平坦均匀，提高电子基板整板电镀均匀性，降低后续CMP工艺难度；也有利于精细线路的制作，提升电子产品的可靠性，从而更好地通过工艺简单、低成本的方式满足高密度互联产品的制造需求。
本申请实施例第五方面提供一种电镀金属的方法，包括以下步骤：
将待电镀基板与本申请实施例第三方面所述的组合物接触，并向所述待电镀基板施加电流进行电镀，使所述待电镀基板上形成金属层。
本申请实施方式中，所述电镀的工艺条件为：电镀温度为10℃-40℃，电流密度为0.5ASD-6ASD，电镀时间为10s-200s。
本申请实施方式中，所述电镀包括第一步电镀、第二步电镀和第三步电镀，所述第一步电镀的电流为0.2ASD-1ASD，电镀时间为1s-15s；所述第二步电镀的电流为0.8ASD-2ASD，电镀时间为10s-100s；所述第三步电镀的电流为2ASD-6ASD，电镀时间为10s-100s。
本申请实施方式中，所述待电镀基板上设置有孔槽，所述金属层包括填充所述孔槽的孔内填充层和沉积在所述孔槽周围的表面沉积层。
本申请第六方面提供一种电子基板，包括基底层和设置在所述基底层上的金属层，所述金属层采用本申请实施例第三方面所述的组合物电镀形成，或采用第五方面所述的方法形成。
本申请实施方式中，所述金属层包括铜或铜合金层、镍或镍合金层、锡或锡合金层、钴或钴合金层、钌或钌合金层、银或银合金层中的任意一种。
本申请实施例还提供一种电子装置，所述电子装置包括本申请实施例第六方面所述的电子基板。
附图说明
图1a是电镀铜填充孔槽形成空洞缺陷的示意图；
图1b是电镀铜填充孔槽形成孔隙缺陷的示意图；
图1c是电镀铜填充孔槽形成超填充的示意图；
图2是现有电镀铜填充孔槽形成不平坦铜层的示意图；
图3是半导体工艺中铜互联层的形成过程示意图；
图4是具有多层铜互联层的基板的结构示意图；
图5是本申请实施例提供的电子基板100的结构示意图；
图6a和图6b为对比例电镀后样品的截面电镜照片；其中图6b为图6a的局部放大图；
图7为本申请实施例1电镀后样品的截面电镜照片；
图8和图9为本申请实施例2电镀后样品的截面电镜照片。
具体实施方式
下面将结合本申请实施例中的附图，对本申请实施例进行说明。
参见图3，图3是半导体工艺中铜互联层的形成过程示意图。图3中，10a为图形化的基板，图形化的基板10a包括基底11和图形化的介质层21，图形化的介质层21设有多个沟槽2。图形化的基板10a经电镀沉积铜后，介质层21的多个沟槽2得到铜填充，形成铜层22，得到电镀后基板10b，铜层22包括填充在沟槽2中的孔内填充层和覆盖在介质层21表面的表面沉积层。电镀后基板10b中，介质层21与铜层22一同构成未经CMP处理的铜互联层20’。电镀后基板10b经CMP处理去除铜层22的表面沉积层后，得到经CMP处理的铜互联层20，即得到CMP处理后基板10c。如图4所示，根据实际需要，还可以是将 CMP处理后基板10c进行进一步铜互联层的制备，例如在铜互联层20上形成铜互联层30，得到具有多层铜互联层的基板10d。为了提高铜互联层20的可靠性，理想的情况是如图3所示，沟槽2中的孔内填充层无空洞、孔隙等缺陷；为了便于进行CMP处理工艺，电镀沉积铜的过程中，理想的情况是铜层22如图3的电镀后基板10b所示，在高密度互联图形区域与低密度互联图形区域铜互联层的厚度差异小，整个铜层22表面较平坦，铜层22整体厚度较小。然而，目前的电镀液配方难以形成表面平整度高且无缺陷的铜互联层，易出现如图1a和图1b所示的空洞、孔隙等缺陷，或者如图2所示的高密度互联图形区域与低密度互联图形区域的铜互联层厚度差异大的问题。其中，高密度互联图形区域是指互联层的互联图形(如孔槽)设置密度(包括孔槽数量或所有孔槽面积占比)相对较高的区域，低密度互联图形区域是指互联层的互联图形(如孔槽)设置密度相对较低的区域。
而且随着半导体工艺精密度的提升，器件特征尺寸的不断减小，布线设计的愈加复杂，获得无缺陷高平整度的铜互联层的难度越来越高，因此对填充小尺寸沟槽所用电镀液配方的要求也越来越严格。为了实现小尺寸沟槽的无缺陷填充，减小高密度互联图形区域与低密度互联图形区域铜互联层的厚度差异，使镀层表面更加平坦均匀，降低后续CMP工艺难度，以实现表面平整度高的无缺陷填充。本申请实施例提供一种整平剂，该整平剂可以在一定程度上抑制金属的沉积，有利于实现小尺寸孔槽(包括沟槽和导通孔)的高平整度无缺陷填充。
本申请实施例提供的整平剂，可作为添加剂加入电镀液中，用于金属电镀，所述整平剂为聚吡啶类化合物，所述聚吡啶类化合物包括式(I)所示的结构单元或式(I)所示结构单元的质子化产物，
式(I)中，R1、R2独立地为取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的亚烷基、含醚氧原子、酯基和/或酰亚胺基的亚芳基、含醚氧原子、酯基和/或酰亚胺基的亚芳基烷基、含醚氧原子、酯基和/或酰亚胺基的亚烷基芳基中的任意一种；R3为单键、取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的连接基团中的任意一种。
本申请实施例提供的上述整平剂具体为含酯基的聚吡啶类化合物，该整平剂具有较好的整平效果，将其整平剂加入到电镀组合物中，用于半导体制造工艺中孔槽的电镀金属填充，可以一定程度地抑制金属的过度沉积，可在保证孔槽内金属无缺陷填充的情况下，避免较小尺寸的孔槽被提前填满，减小不同密度的布线区域电镀金属层的厚度差异，有效降低镀层表面的平台起伏，获得更好的平坦化效果，从而有利于后续CMP工艺的进行；本申请实施例的整平剂聚合物分子结构稳定，可使得所得镀层内部杂质含量低，提高镀层可靠性。
本申请实施方式中，聚吡啶类化合物包括式(I)所示结构单元的质子化产物和卤素离子，也即，聚吡啶类化合物包括式(II)所示的结构单元，卤素离子包括氟离子、氯离子、溴离子和碘离子中的任意一种。式(I)所示结构单元的质子化产物可以表示为式(I-1)，可以理解地，式(I-1)和式(II)中的各取代基团与式(I)中的相对应取代基团一致。式(II)中，X-为卤素离子。一些实施例中，式(I)中的两个X-为相同的卤素离子，以便于整平剂的制备。
本申请实施方式中，R1、R2、R3中，取代或非取代的亚烷基的碳原子数可以是1-30；一些实施例中， 取代或非取代的亚烷基的碳原子数具体可以是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、30。具体地，R1、R2、R3例如可以是取代或非取代的亚甲基、取代或非取代的亚乙基、取代或非取代的亚丙基、取代或非取代的亚异丙基、取代或非取代的亚丁基、取代或非取代的亚异丁基、取代或非取代的亚新戊基、取代或非取代的亚己基等。
本申请实施方式中，R1、R2、R3中，取代或非取代的亚芳基的碳原子数可以是6-30；一些实施例中，取代或非取代的亚芳基的碳原子数具体可以是6、7、8、9、10、11、12、13、14、15、16、17、18、19、20、21、22、23、24、25、26、27、28、29、30。具体地，R1、R2、R3例如可以是取代或非取代的亚苯基、取代或非取代的亚联苯基、取代或非取代的亚三联苯基、取代或非取代的亚芴基、取代或非取代的亚萘基、取代或非取代的亚蒽基等。
本申请实施方式中，R1、R2、R3中，取代或非取代的亚芳基烷基的碳原子数可以是7-40；一些实施例中，取代或非取代的亚芳基烷基的碳原子数具体可以是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、40。本申请实施方式中，R1、R2、R3中，取代或非取代的亚烷基芳基的碳原子数可以是7-40；一些实施例中，取代或非取代的亚烷基芳基的碳原子数具体可以是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、40。
本申请实施方式中，R1、R2、R3中，取代的亚烷基、取代的亚芳基、取代的亚芳基烷基、取代的亚烷基芳基中的取代基团可以但不限于是卤素原子。
本申请实施方式中，R1中，含醚氧原子、酯基和/或酰亚胺基的亚烷基的碳原子数可以是2-30，碳原子数具体例如是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、30；含醚氧原子、酯基和/或酰亚胺基的亚芳基的碳原子数可以是6-30，碳原子数具体例如是6、7、8、9、10、11、12、13、14、15、16、17、18、19、20、21、22、23、24、25、26、27、28、29、30；含醚氧原子、酯基和/或酰亚胺基的亚芳基烷基的碳原子数可以是7-40，碳原子数具体例如是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、40；含醚氧原子、酯基和/或酰亚胺基的亚烷基芳基可以是7-40，碳原子数具体例如是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、40。含醚氧原子、酯基和/或酰亚胺基的亚烷基即含醚氧原子、酯基、酰亚胺基中任意一种或多种的亚烷基；含醚氧原子、酯基和/或酰亚胺基的亚芳基即含醚氧原子、酯基、酰亚胺基中任意一种或多种的亚芳基；含醚氧原子、酯基和/或酰亚胺基的亚芳基烷基即含醚氧原子、酯基、酰亚胺基中任意一种或多种的亚芳基烷基；含醚氧原子、酯基和/或酰亚胺基的亚烷基芳基即含醚氧原子、酯基、酰亚胺基中任意一种或多种的亚烷基芳基。
本申请一些实施方式中，R1可以是含一个或多个醚氧原子的亚烷基、含一个或多个醚氧原子的亚芳基、含一个或多个醚氧原子的芳基烷基、或者含一个或多个醚氧原子的烷基芳基。R1为含醚氧原子的基团可以更好地起到抑制金属过度沉积的效果，减小不同密度的布线区域电镀金属层的厚度差异，获得更好的平坦化效果。
本申请一些实施方式中，R1可以是含醚氧原子的亚烷基，含醚氧原子的亚烷基可表示为-(R4O)x-L-(R5O)y-R5-，其中，R4、R5可以是相同或不同的亚烷基，x为大于或等于0的整数，y为大于或等于1的整数，L表示单键或至少一个醚氧嵌段。R4、R5具体可以是碳原子数为2-10的亚烷基，例如可以是亚乙基、亚丙基、亚异丙基等。x、y的取值可以是1-300。一些实施例中，x、y的取值可以是1-100，一些实施例中，x、y的取值可以是1-30；一些实施例中，x、y的取值具体可以是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、30。R1链越长，对电镀金属的抑制效果越强，在相对更高密度布线区的整平性会变好。因此，本申请实施例可以根据应用场景中的布线密度来选择不同的R1链长。
本申请一实施方式中，x等于0，L为单键，R5为亚乙基，此时R1表示为-(CH2CH2O)y-CH2CH2-；本申请一实施方式中，x等于0，L为单键，R5为亚异丙基，此时R1表示为-(CH2CHCH2O)y-CH2CHCH2-；本申请一实施方式中，x为大于或等于1的整数，L为单键，R4为亚乙基，R5为亚异丙基，此时R1表示为-(CH2CH2O)x-(CH2CHCH2O)y-CH2CHCH2-。上述实施例中，L均为单键，本申请一些实施例中，L还可以是至少一个醚氧嵌段；例如一些实施例中，L为一个醚氧嵌段-(R6O)k-；一些实施例中，L为两个醚氧嵌段-(R6O)k-(R7O)l-，k、l为大于或等于1的整数。
本申请实施方式中，R3中，含醚氧原子、酯基和/或酰亚胺基的连接基团具体可以是含醚氧原子、酯基 和/或酰亚胺基的亚烷基、含醚氧原子、酯基和/或酰亚胺基的亚芳基、含醚氧原子、酯基和/或酰亚胺基的亚芳基烷基、含醚氧原子、酯基和/或酰亚胺基的亚烷基芳基，上述基团选择与R1、R2相同，此处不再赘述。一些实施例中，含酰亚胺基的连接基团可以是-HN-C(＝O)-R-C(＝O)-NH-，R可以是取代或非取代的亚烷基。
本申请一些实施例中，聚吡啶类化合物仅包含式(I)所示结构单元的质子化产物和卤素离子，聚吡啶类化合物表示为式(1)所示的聚吡啶盐化合物：
式(1)中，n为大于或等于2的整数。一些实施例中，n例如可以是2-15的整数，具体地，n可以是2、3、4、5、6、7、8、9、10、11、12、13、14、15。
相应地，本申请实施例还提供一种整平剂的制备方法，包括：
步骤S101、将式(a)所示的两端带羟基的化合物与式(b)所示的含酰卤基团的化合物在第一温度下反应得到中间体；
步骤S102、将所得中间体与式(c)所示的含双吡啶结构的化合物在第二温度下反应得到整平剂，整平剂包括聚吡啶类化合物，聚吡啶类化合物包括式(I)所示的结构单元或式(I)所示结构单元的质子化产物，
HO-R1-OH式(a)
式(a)中，R1为取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的亚烷基、含醚氧原子、酯基和/或酰亚胺基的亚芳基、含醚氧原子、酯基和/或酰亚胺基的亚芳基烷基、含醚氧原子、酯基和/或酰亚胺基的亚烷基芳基中的任意一种；式(b)中，X1和X为相同或不同的卤素原子；R2为取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的亚烷基、含醚氧原子、酯基和/或酰亚胺基的亚芳基、含醚氧原子、酯基和/或酰亚胺基的亚芳基烷基、含醚氧原子、酯基和/或酰亚胺基的亚烷基芳基中的任意一种；式(c)中，R3为单键、取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的连接基团中的任意一种；
式(I)中，R1、R2独立地为取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的亚烷基、含醚氧原子、酯基和/或酰亚胺基的亚芳基、含醚氧原子、酯基和/或酰亚胺基的亚芳基烷基、含醚氧原子、酯基和/或酰亚胺基的亚烷基芳基中的任意一种；R3为单键、取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的连接基团中的任意一种。
由上述反应过程可知，式(a)中的R1与式(I)中的R1相同，式(b)中的R2与式(I)中的R2相同，式(c)中的R3与式(I)中的R3相同，此处不再赘述。
本申请一些实施方式中，聚吡啶类化合物包括式(II)所示的结构单元，X-为卤素离子。
式(II)中的X-来源于式(b)中的卤素原子X。
本申请一些实施方式中，式(a)所示的两端带羟基的化合物可以是具有式(a-1)、式(a-2)、式(a-3)所示的结构，式(a-1)、式(a-2)、式(a-3)中m、n为大于或等于1的整数，例如可以是1-300；一些实施例中，m、n的取值具体可以是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、30。
本申请实施方式中，步骤S101中，第一温度可以是-20℃至25℃；一些实施例中，第一温度可以是0℃至10℃。步骤S101的反应过程中，可以是采用二氯甲烷等作为溶剂。
本申请实施方式中，步骤S102中，第二温度可以是25℃至200℃；一些实施例中，第二温度可以是50℃至150℃。
本申请实施例制备得到的聚吡啶类化合物为固体物。
本申请实施例还提供一种电镀组合物，该电镀组合物包括金属离子源，以及本申请实施例上述的整平剂。该电镀组合物可以作为电镀沉积金属层的电镀液。
本申请实施方式中，电镀组合物中，所述整平剂的浓度为1ppm-100ppm。一些实施例中，整平剂的浓度为2ppm-80ppm；一些实施例中，整平剂的浓度为5ppm-50ppm。一些实施例中，整平剂的浓度为10ppm-30ppm。具体地，一些实施例中，整平剂的浓度可以是1ppm、2ppm、5ppm、8ppm、10ppm、12ppm、15ppm、18ppm、20ppm、25ppm、30ppm、40ppm、50ppm。控制电镀组合物中的整平剂浓度在适合范围，有利于获得适中的金属沉积速度，更好地实现小尺寸孔槽无缺陷高平整度的整板填充，从而有利于精细线路的制作，有利于提升电子产品的可靠性。
本申请实施方式中，电镀组合物还包括加速剂、抑制剂、无机添加剂中的一种或多种。整平剂与加速剂、抑制剂等的相互协同配合，可以有效降低铜层表面粗糙度，在布线密度不同的区域也可实现表面面铜厚度均匀，可以更好地实现小尺寸孔槽无缺陷高平整度的整板填充，降低后续抛光工艺的技术难度。
本申请实施方式中，加速剂包括3-巯基-1-丙烷磺酸钠(MPS)、聚二硫二丙烷磺酸钠(SPS)和N,N-二甲基-二硫甲酰胺丙磺酸钠(DPS)中的一种或多种。加速剂的加入可以起到去极化效果加速沟槽底部金属的沉积，以及细化金属层的晶粒的作用。本申请实施方式中，电镀组合物中，加速剂的浓度可以是1ppm-50ppm。一些实施方式中，电镀组合物中，加速剂的浓度可以是2ppm-40ppm。一些实施方式中，电镀组合物中，加速剂的浓度可以是5ppm-35ppm。一些实施方式中，电镀组合物中，加速剂的浓度可以是10ppm-30ppm。
本申请实施方式中，抑制剂包括聚乙二醇(PEG)、聚丙二醇(PPG)、嵌段共聚物PEO-PPO-PEO(聚环氧乙烷-聚环氧丙烷-聚环氧乙烷)、嵌段共聚物PPO-PEO-PPO(聚环氧丙烷-聚环氧乙烷-聚环氧丙烷)、聚氧乙烷(EO)与聚氧丙烷(PO)的无规共聚物、丙二醇嵌段聚醚中的一种或多种。抑制剂的加入可以抑制表面铜的过快沉积，防止孔槽的提前封口，也有利于在完成镀铜后获得较薄的表面铜。本申请实施方式中，抑制剂在电镀组合物中的浓度可以是1ppm-2000ppm。一些实施方式中，抑制剂在电镀组合物中的浓度为10ppm-1000ppm。一些实施方式中，抑制剂在电镀组合物中的浓度为100ppm-1000ppm。一些实施方式中，抑制剂在电镀组合物中的浓度为150ppm-500ppm。
本申请实施方式中，无机添加剂包括氯离子，氯离子在电镀组合物中的浓度为1ppm-100ppm。一些实施方式中，电镀组合物中，氯离子的浓度可以是1ppm、5ppm、10ppm、20ppm、30ppm、40ppm、50ppm、 60ppm、70ppm、80ppm、90ppm、100ppm。氯离子的加入可以使镀层结晶致密、精细不粗糙。
本申请实施方式中，电镀组合物还包括至少一种酸；所述至少一种酸包括硫酸和甲基磺酸中的一种或多种。本申请实施方式中，至少一种酸在电镀组合物中的浓度为1g/L-100g/L。一些实施方式中，至少一种酸在电镀组合物中的浓度具体例如可以是1g/L、10g/L、20g/L、30g/L、40g/L、50g/L、55g/L、60g/L、70g/L、80g/L、90g/L、100g/L。适合的酸体系和酸浓度有利于获得适合的电镀沉积速率。
本申请实施方式中，金属离子源包括铜离子源、镍离子源、锡离子源、钴离子源、钌离子源、银离子源中的任意一种。可以理解地，预沉积哪种金属层，则电镀组合物中的金属离子源相应地包括预沉积的金属层中金属元素对应的金属离子源。例如，预沉积金属铜层，则金属离子源包括铜离子源。
本申请实施方式中，铜离子源包括五水硫酸铜和甲基磺酸铜中的一种或多种。采用上述的铜离子源的酸体系进行电镀，电流效率高，对环境友好，且能够更好地通过各种添加剂的配合实现盲孔的填充。本申请实施方式中，以铜离子计，铜离子源在电镀组合物中的浓度为1g/L-100g/L。一些实施方式中，以铜离子计，铜离子源在电镀组合物中的浓度具体例如可以是1g/L、10g/L、20g/L、30/L、40g/L、50g/L、60g/L、70g/L、80g/L、90g/L、100g/L。将铜离子源控制在适合的含量范围，有利于兼顾沉积速度以及所得铜镀层的光亮度和平整度。
本申请实施例提供的新型整平剂，将其应用于铜电镀液等金属电镀液中，可以在孔槽填充过程中得到表面金属厚度均匀，板面外观良好的样品，适用于精密加工。且本申请实施例的整平剂操作窗口宽，在对孔槽尺寸介于28nm-1.2μm的情况下的孔槽进行电镀时，能够完成所有尺寸孔槽的无孔隙填充，有利于提高最终产品的可靠性。
本申请实施例还提供上述的整平剂和/或电镀组合物在电镀金属过程中的应用。所述应用中，电镀金属可以是包括电镀铜及铜合金、电镀镍及镍合金、电镀锡及锡合金、电镀钴及钴合金、电镀钌及钌合金、电镀银及银合金中的任意一种。
本申请实施方式中，电镀金属包括印刷电路板制备工艺中的电镀金属、集成电路金属互联工艺中的电镀金属、或电子封装工艺中的电镀金属。具体地，电镀金属可以是包括大马士革沟槽填充、硅通孔填充、基板再布线、金属凸点沉积、或导通孔填充等工艺中的电镀金属。
本申请实施方式中，电镀金属包括电子基板上孔槽的全金属电镀填充。电子基板可以是普通基板、印制电路板、封装基板等，孔槽包括沟槽和/或导通孔，导通孔可以是包括通孔、盲孔和埋孔。全金属填充可以是电镀铜及铜合金、电镀镍及镍合金、电镀锡及锡合金、电镀钴及钴合金、电镀钌及钌合金、或电镀银及银合金填充。
本申请实施例提供的整平剂用于电子基板上孔槽的全金属电镀填充，可实现纳米级小尺寸孔槽的无缺陷填充，同时能够减小高密度互联图形区域与低密度互联图形区域铜互联层的厚度差异，使镀层表面更加平坦均匀，提高电子基板整板电镀均匀性，降低后续CMP工艺难度；也有利于精细线路的制作，提升电子产品的可靠性，从而更好地通过工艺简单、低成本的方式满足高密度互联产品的制造需求。
本申请实施例还提供一种电镀金属的方法，包括以下步骤：
将待电镀基板与本申请实施例上述的电镀组合物接触，并向待电镀基板施加电流进行电镀，使待电镀基板上形成金属层。
具体地，可以是将待电镀基板作为阴极浸入至电镀组合物中，电镀组合物即电镀液作为电解质，与可溶或者不可溶的阳极共同构成导电回路，从而实现待电镀基板上的金属沉积。
本申请实施方式中，待电镀基板上设有孔槽，金属层包括填充孔槽的孔内填充层和沉积在孔槽周围的表面沉积层。孔槽包括沟槽和/或导通孔，导通孔可以是包括通孔、盲孔、埋孔中的一种或多种。
本申请实施方式中，孔槽的横向尺寸可以是为28nm-1.2μm，深度可以是100nm-300nm。具体地，孔槽的横向尺寸例如可以是为28nm、30nm、35nm、40nm、45nm、50nm、60nm、70nm、80nm、90nm、100nm、200nm、300nm、400nm、500nm、600nm、700nm、800nm、900nm、1.0μm、1.1μm、1.2μm。深度例如可以是100nm、200nm、300nm。待电镀基板上可以是同时具有不同横向尺寸和深度的孔槽。其中，沟槽的横向尺寸是指沟槽的宽度，导通孔的横向尺寸是指导通孔的直径。
本申请实施方式中，待电镀基板上可以设有不同孔槽分布密度的区域，如包括高密度孔槽分布区域和低密度孔槽分布区域。
一般地，在电镀之前会将孔槽内壁进行金属化处理，如在孔槽内壁化学镀一层金属种子层，如铜种子层。
本申请实施方式中，电镀的工艺条件为：电镀温度为10℃-40℃，电流密度为0.5ASD-6ASD，电镀时 间为10s-200s。
本申请实施方式中，所述电镀包括第一步电镀、第二步电镀和第三步电镀，所述第一步电镀的电流为0.2ASD-1ASD，电镀时间为1s-15s；所述第二步电镀的电流为0.8ASD-2ASD，电镀时间为10s-100s；所述第三步电镀的电流为2ASD-6ASD，电镀时间为10s-100s。本申请实施例通过分步电镀可以更好地获得无缺陷填充，并获得适合的表面金属层厚度。以电镀铜为例，第一步电镀可以较好地修复铜种子层；第二步电镀可以较好地实现孔隙填充；第三步电镀则可以表面增厚方便后续抛光研磨。
参见图5，本申请实施例还提供一种电子基板100，包括基底层101和设置在基底层上的金属层102，金属层102采用本申请实施例上述的电镀组合物电镀形成，或采用本申请实施例上述的电镀金属的方法形成。
本申请实施方式中，金属层102包括铜或铜合金层、镍或镍合金层、锡或锡合金层、钴或钴合金层、钌或钌合金层、银或银合金层中的任意一种。
本申请实施方式中，基底层101包括衬底1011和介质层1012，基底层101上设有孔槽103，金属层102包括填充孔槽103的孔内填充层1021和沉积在孔槽103周围的表面沉积层1022。可以理解地，一些实施方式中，当表面沉积层1022通过CMP处理工艺去除后，金属层102仅包括填充孔槽103的孔内填充层1021。
本申请实施方式中，基底层101与金属层102之间还可以是包括对孔槽103进行金属化处理形成的金属种子层，如铜种子层。
本申请实施方式中，孔槽103的横向尺寸可以是为28nm-1.2μm，深度可以是100nm-300nm。基底层101上可以是设置多个孔槽103，多个孔槽103可以是具有不同横向尺寸和深度，也可以是具有相同横向尺寸和深度。
本申请实施方式中，表面沉积层1022的厚度小于8μm。本申请实施方式中，高密度互联图形区域的表面沉积层1022的平均厚度H1与低密度互联图形区域表面沉积层1022的平均厚度H2的比值小于或等于1.7。一些实施例中，H1与H2的比值小于或等于1.5。一些实施例中，H1与H2的比值小于或等于1.3。一些实施例中，H1与H2的比值小于或等于1.1。
可以理解地，本申请实施例图5所示的电子基板100是未经过CMP处理的结构示意图，在实际应用中，表面沉积层1022会通过抛光工艺去除。
本申请实施例还提供一种电子装置，电子装置采用本申请实施例上述的电子基板100。
下面分多个实施例对本申请实施例进行进一步的说明。
实施例1
一种如式1所示的聚吡啶类化合物A：
其中，R1为R2为R3为单键，X-为Cl-，n为4，*表示连接位置。
聚吡啶类化合物A的制备方法如下：
(1)向装有温度计、搅拌器和恒压滴液漏斗的三口烧瓶中，加入50mL二氯甲烷、20mmol二缩三乙二醇和40mmol三乙胺，开启搅拌器，控制温度在0～10℃；
(2)将40mmol 4-氯丁酰氯溶解在二氯甲烷中，并转移至恒压滴液漏斗中，使4-氯丁酰氯溶液以1mL/min的速度缓慢往下滴，控制温度在0～10℃；滴加完成后，继续保持室温反应12h以上；之后将反应后的混合物旋蒸除去二氯甲烷，再用乙酸乙酯和水溶解，提取乙酸乙酯有机相，水洗后旋蒸，得到酯基中间体；
(3)向装有搅拌器的圆底烧瓶中，加入20mmol上述所得酯基中间体和20mmol 4,4'-联吡啶，打开搅拌器，升温至120℃，反应12h后，降温到室温，得到最终以固体状态存在的聚吡啶类化合物A。
一种铜电镀液，包括如下质量配比的各组分：
五水硫酸铜(以铜离子计):50g/L
硫酸：50g/L
氯离子：50ppm
聚吡啶类化合物A：10ppm
加速剂SPS(聚二硫二丙烷磺酸钠)：25ppm
抑制剂L64(丙二醇嵌段聚醚)：300ppm。
为体现本申请实施例提供的整平剂的效果，以不添加整平剂的铜电镀液作为对比例，对比例的铜电镀液与实施例1的区别仅在于不添加聚吡啶类化合物A。
分别使用实施例1的铜电镀液和对比例的铜电镀液对设有直径为60nm～120nm、深度为120nm～250nm的沟槽结构的待电镀基板实施电镀铜填充，待电镀基板为具备PVD铜种子层的图形片，电镀温度为常温电镀，电镀过程采用三步电流法，第一步电流为0.65ASD，电镀时间为6秒，第二步电流为1ASD，电镀时间为40秒，第三步电流为6ASD，电镀时间为45秒。
图6a和图6b为对比例电镀后样品的截面电镜照片；其中图6b为图6a的局部放大图。由图6a和图6b可以看出，在未添加整平剂的情况下，高密度沟槽区域和低密度沟槽区域的铜层表面起伏极大，高密度沟槽区域与低密度沟槽区域的铜层平均厚度比值高达1.806，难以进行后续的CMP操作。
图7为本申请实施例1电镀后样品的截面电镜照片。由图7可以看出，在添加聚吡啶类化合物A整平剂的情况下，高密度沟槽区域和低密度沟槽区域的铜层表面起伏较小，高密度沟槽区域与低密度沟槽区域的铜层平均厚度比值仅为1.023，平整度得到大幅提升，从而可以极大减轻后续CMP抛光工艺的负担。另外，由图7也可知，添加聚吡啶类化合物A整平剂的电镀液实现了小尺寸沟槽的无缺陷填充，以及不同尺寸、不同布线密度的高平整度同时填充。
实施例2
一种如式1所示的聚吡啶类化合物B：
其中，R1为R2为
R3为X-为Cl-，n为4，*表示连接位置。
聚吡啶类化合物B的制备方法如下：
(1)向装有温度计、搅拌器和恒压滴液漏斗的三口烧瓶中，加入50mL二氯甲烷、20mmol二缩三乙二醇和40mmol三乙胺，开启搅拌器，控制温度在0～10℃；
(2)将40mmol 4-氯丁酰氯溶解在二氯甲烷中，并转移至恒压滴液漏斗中，使4-氯丁酰氯溶液以1mL/min的速度缓慢往下滴，控制温度在0～10℃；滴加完成后，继续保持室温反应12h以上；之后将反应后的混合物旋蒸除去二氯甲烷，再用乙酸乙酯和水溶解，提取乙酸乙酯有机相，水洗后旋蒸，得到酯基中间体；
(3)向装有搅拌器的圆底烧瓶中，加入20mmol上述所得酯基中间体和20mmol式(c-1)所示的含双吡啶结构的化合物，打开搅拌器，升温至120℃，反应12h后，降温到室温，得到最终以固体状态存在的聚吡啶类化合物B。
一种铜电镀液，包括如下质量配比的各组分：
五水硫酸铜(以铜离子计):50g/L
硫酸：50g/L
氯离子：50ppm
聚吡啶类化合物A：10ppm
加速剂SPS(聚二硫二丙烷磺酸钠)：25ppm
抑制剂L65(丙二醇嵌段聚醚)：150ppm。
使用实施例2的铜电镀液对具有直径为40～120nm、深度为100～250nm的沟槽结构的待电镀基板实施电镀铜填充，待电镀基板为具备PVD铜种子层的图形片，电镀温度为常温电镀，电镀过程采用三步电流法，第一步电流为0.65ASD，电镀时间为6秒，第二步电流为1ASD，电镀时间为40秒，第三步电流为6ASD，电镀时间为45秒。
图8和图9为本申请实施例2电镀后样品的截面电镜照片。由图8和图9可以看出，在添加聚吡啶类化合物B整平剂的情况下，高密度沟槽区域和低密度沟槽区域的铜层表面起伏较小，高密度沟槽区域与低密度沟槽区域的铜层平均厚度比值仅为1.0，平整度得到大幅提升，从而可以极大减轻后续CMP抛光工艺的负担。由图8和图9也可知，添加聚吡啶类化合物A整平剂的电镀液实现了小尺寸沟槽的无缺陷填充，以及不同尺寸、不同布线密度的高平整度同时填充。
由上述实施例可知，本申请实施例的新型整平剂加入到电镀组合物中，用于电镀铜填充，可以保证纳米级亚微米级不同尺寸沟槽的金属铜的无孔隙填充，且整平剂通过抑制铜的过度沉积最终会获得较好的平坦化效果，保证了较小尺寸的图形不会被提前填满，有效地降低了镀层表面平台起伏，从而得到面铜厚度均匀，板面外观良好的样品，降低后续抛光工艺难度，提高最终产品的可靠性。
应理解，本文中涉及的第一、第二以及各种数字编号仅为描述方便进行的区分，并不用来限制本申请的范围。
本申请中，“和/或”，描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B的情况，其中A,B可以是单数或者复数。字符“/”一般表示前后关联对象是一种“或”的关系。
本申请中，“至少一个”是指一个或者多个，“多个”是指两个或两个以上。“以下至少一项(个)”或其类似表达，是指的这些项中的任意组合，包括单项(个)或复数项(个)的任意组合。例如，“a,b,或c中的至少一项(个)”，或，“a,b,和c中的至少一项(个)”，均可以表示：a,b,c,a-b(即a和b),a-c,b-c,或a-b-c，其中a,b,c分别可以是单个，也可以是多个。
应理解，在本申请的各种实施例中，上述各过程的序号的大小并不意味着执行顺序的先后，部分或全部步骤可以并行执行或先后执行，各过程的执行顺序应以其功能和内在逻辑确定，而不应对本申请实施例的实施过程构成任何限定。

Claims (28)

  1. 一种整平剂，其特征在于，所述整平剂为聚吡啶类化合物，所述聚吡啶类化合物包括式(I)所示的结构单元或式(I)所示结构单元的质子化产物，
    式(I)中，R1、R2独立地为取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的亚烷基、含醚氧原子、酯基和/或酰亚胺基的亚芳基、含醚氧原子、酯基和/或酰亚胺基的亚芳基烷基、含醚氧原子、酯基和/或酰亚胺基的亚烷基芳基中的任意一种；R3为单键、取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的连接基团中的任意一种。
  2. 如权利要求1所述的整平剂，其特征在于，所述聚吡啶类化合物包括所述式(I)所示结构单元的质子化产物和卤素离子；所述卤素离子包括氟离子、氯离子、溴离子和碘离子中的任意一种。
  3. 如权利要求1或2所述的整平剂，其特征在于，所述R1、R2、R3中，取代或非取代的亚烷基的碳原子数为1-30；取代或非取代的亚芳基的碳原子数为6-30。
  4. 如权利要求1或2所述的整平剂，其特征在于，所述含醚氧原子的亚烷基表示为-(R4O)x-L-(R5O)y-R5-，其中，R4、R5为相同或不同的亚烷基，x为大于或等于0的整数，y为大于或等于1的整数，L表示单键或至少一个醚氧嵌段。
  5. 一种整平剂的制备方法，其特征在于，包括：
    将式(a)所示的两端带羟基的化合物与式(b)所示的含酰卤基团的化合物在第一温度下反应得到中间体；
    再将所述中间体与式(c)所示的含双吡啶结构的化合物在第二温度下反应得到整平剂，所述整平剂包括聚吡啶类化合物，所述聚吡啶类化合物包括式(I)所示的结构单元或式(I)所示结构单元的质子化产物，
    式(a)中，R1为取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的亚烷基、含醚氧原子、酯基和/或酰亚胺基的亚芳基、含醚氧原子、酯基和/或酰亚胺基的芳基烷基、含醚氧原子、酯基和/或酰亚胺基的亚烷基芳基中的任意一种；式(b)中，X1和X为相同或不同的卤素原子；R2为取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的亚烷基、含醚氧原子、酯基和/或酰亚胺基的亚芳基、含醚氧原子、酯基和/或酰亚胺基的芳基烷基、含醚氧原子、酯基和/或酰亚胺基的亚烷基芳基中的任意一种；式(c)中，R3为单键、取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的连接基团中的任意一种；
    式(I)中，R1、R2独立地为取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的亚烷基、含醚氧原子、酯基和/或酰亚胺基的亚芳基、含醚氧原子、酯基和/或酰亚胺基的芳基烷基、含醚氧原子、酯基和/或酰亚胺基的亚 烷基芳基中的任意一种；R3为单键、取代或非取代的亚烷基、取代或非取代的亚芳基、取代或非取代的亚芳基烷基、取代或非取代的亚烷基芳基、含醚氧原子、酯基和/或酰亚胺基的连接基团中的任意一种。
  6. 如权利要求5所述的制备方法，其特征在于，所述第一温度为-20℃至25℃。
  7. 如权利要求5或6所述的制备方法，其特征在于，所述第二温度为25℃至200℃。
  8. 一种组合物，其特征在于，所述组合物包括金属离子源，以及权利要求1-4任一项所述的整平剂或权利要求5-7任一项所述的制备方法制得的整平剂。
  9. 如权利要求8所述的组合物，其特征在于，所述电镀组合物中，所述整平剂的浓度为1ppm-100ppm。
  10. 如权利要求8或9所述的组合物，其特征在于，所述电镀组合物还包括加速剂、抑制剂、无机添加剂中的一种或多种。
  11. 如权利要求10所述的组合物，其特征在于，所述加速剂包括3-巯基-1-丙烷磺酸钠、聚二硫二丙烷磺酸钠和N,N-二甲基-二硫甲酰胺丙磺酸钠中的一种或多种；所述加速剂在所述组合物中的浓度为1ppm-50ppm。
  12. 如权利要求10所述的组合物，其特征在于，所述抑制剂包括聚乙二醇、聚丙二醇、嵌段共聚物PEO-PPO-PEO、嵌段共聚物PPO-PEO-PPO、EO与PO的无规共聚物、丙二醇嵌段聚醚中的一种或多种；所述抑制剂在所述组合物中的浓度为1-2000ppm。
  13. 如权利要求10所述的组合物，其特征在于，所述无机添加剂包括氯离子，所述氯离子在所述组合物中的浓度为1ppm-100ppm。
  14. 如权利要求8-13任一项所述的组合物，其特征在于，所述组合物还包括至少一种酸；所述至少一种酸包括硫酸和甲基磺酸中的一种或多种。
  15. 如权利要求14所述的组合物，其特征在于，所述至少一种酸在所述组合物中的浓度为1g/L-100g/L。
  16. 如权利要求8-15任一项所述的组合物，其特征在于，所述金属离子源包括铜离子源、镍离子源、锡离子源、钴离子源、钌离子源、银离子源中的任意一种。
  17. 如权利要求16所述的组合物，其特征在于，所述铜离子源包括五水硫酸铜和甲基磺酸铜中的一种或多种；以铜离子计，所述铜离子源在所述组合物中的浓度为1g/L-100g/L。
  18. 如权利要求1-4任一项所述的整平剂或权利要求5-7任一项所述的制备方法制得的整平剂，或权利要求8-17任一项所述的组合物在电镀金属中的应用。
  19. 如权利要求18所述的应用，其特征在于，所述电镀金属包括电镀铜及铜合金、电镀镍及镍合金、电镀锡及锡合金、电镀钴及钴合金、电镀钌及钌合金、电镀银及银合金中的任意一种。
  20. 如权利要求18或19所述的应用，其特征在于，所述电镀金属包括电子基板上孔槽的全金属电镀填充。
  21. 如权利要求18-20任一项所述的应用，其特征在于，所述电镀金属包括印刷电路板制备工艺中电镀金属、集成电路金属互联工艺中电镀金属、电子封装工艺中电镀金属。
  22. 一种电镀金属的方法，其特征在于，包括以下步骤：
    将待电镀基板与权利要求8-17任一项所述的组合物接触，并向所述待电镀基板施加电流进行电镀，使所述待电镀基板上形成金属层。
  23. 如权利要求22所述的方法，其特征在于，所述电镀的工艺条件为：电镀温度为10℃-40℃，电流密度为0.5ASD-6ASD，电镀时间为10s-200s。
  24. 如权利要求23所述的方法，其特征在于，所述电镀包括第一步电镀、第二步电镀和第三步电镀，所述第一步电镀的电流为0.2ASD-1ASD，电镀时间为1s-15s；所述第二步电镀的电流为0.8ASD-2ASD，电镀时间为10s-100s；所述第三步电镀的电流为2ASD-6ASD，电镀时间为10s-100s。
  25. 如权利要求23所述的方法，其特征在于，所述待电镀基板上设置有孔槽，所述金属层包括填充所述孔槽的孔内填充层和沉积在所述孔槽周围的表面沉积层。
  26. 一种电子基板，其特征在于，包括基底层和设置在所述基底层上的金属层，所述金属层采用权利要求8-17任一项所述的组合物电镀形成，或采用权利要求22-25任一项所述的电镀金属的方法形成。
  27. 如权利要求26所述的电子基板，其特征在于，所述金属层包括铜或铜合金层、镍或镍合金层、锡或锡合金层、钴或钴合金层、钌或钌合金层、银或银合金层中的任意一种。
  28. 一种电子装置，其特征在于，所述电子装置采用权利要求26-27任一项所述的电子基板。
PCT/CN2023/115935 2022-08-31 2023-08-30 一种整平剂、组合物及其应用 WO2024046395A1 (zh)

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US20050079803A1 (en) * 2003-10-10 2005-04-14 Siddiqui Junaid Ahmed Chemical-mechanical planarization composition having PVNO and associated method for use
CN102362013A (zh) * 2008-11-26 2012-02-22 恩索恩公司 用基于联吡啶的整平剂在微电子装置中电沉积铜
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