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CN-115427613-B - Acidic aqueous composition for electrolytic deposition of copper deposits

CN115427613BCN 115427613 BCN115427613 BCN 115427613BCN-115427613-B

Abstract

The present invention relates to an acidic aqueous composition for electrolytic copper plating comprising (i) copper (II) ions, (II) one or more inhibitors consisting of or comprising one single N-heteroaromatic monocyclic ring comprising at least two ring nitrogen atoms and more than one substituent covalently linked to one of the ring nitrogen atoms and/or to a ring carbon atom, wherein the substituents are independently or comprise one or more linear or branched polyalkylene glycol moieties and/or one or more linear or branched polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moieties, provided that if the inhibitor comprises OH groups it is the terminal OH groups of the polyalkylene glycol moieties, polyalkylene glycol block polyalkylene glycol and random polyalkylene glycol moieties, respectively, and the inhibitor does not comprise NH 2 groups, halogen atoms and sulfur atoms, a method of electrolytic copper plating using the acidic aqueous composition, and a specific inhibitor as defined above.

Inventors

  • R. SCHMIDT
  • J. Gaida
  • W. Roland
  • PALM JOERG
  • H. Jeha

Assignees

  • 德国艾托特克有限两合公司

Dates

Publication Date
20260512
Application Date
20210422
Priority Date
20200423

Claims (20)

  1. 1. An acidic aqueous composition for electrodepositing copper deposits, the composition comprising: (i) The ion of copper (II) is used for preparing the copper-ion alloy, (Ii) One or more inhibitors comprising: a single N-heteroaromatic monocyclic ring comprising at least two ring nitrogen atoms and more than one substituent covalently linked to one of the ring nitrogen atoms and/or a ring carbon atom, wherein the substituents are independently or comprise: one or more linear or branched polyalkylene glycol moieties, and/or One or more than one linear or branched polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moiety, Provided that If the inhibitor comprises OH groups, it is the terminal OH groups of the polyalkylene glycol moiety, polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moiety, respectively, and The inhibitor does not contain NH 2 groups, halogen atoms and sulfur atoms, Wherein the one or more inhibitors in (ii) are selected from the group consisting of: wherein each is independently R represents a linear or branched polyalkylene glycol moiety or a linear or branched polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moiety and R 1 is alkyl, and N represents 0,1, 2,3,4 or 5, and Wherein the inhibitor in (ii) has a weight average molecular weight (Mw) in the range of 500 g/mol to 5000 g/mol.
  2. 2. The composition of claim 1, wherein n represents 0,1, 2 or 3.
  3. 3. The composition of claim 1, further comprising: (iii) At least one other inhibitor different from the inhibitor in (ii), and (Iv) At least one accelerator different from the inhibitors described in (ii) and (iii).
  4. 4. A composition according to claim 3, wherein the at least one other inhibitor than the inhibitor in (ii) is a polymer comprising nitrogen and/or oxygen atoms.
  5. 5. The composition of any one of claims 1-4, wherein the one or more inhibitors in (ii) are selected from the group consisting of: (IIa)、 (IIb)、 (IIb’)、 (IIc)、 (IId) (IIe), Wherein each is independently of the other A represents an integer in the range of 2 to 22, and B represents an integer in the range of 2 to 22.
  6. 6. The composition of claim 5, wherein a represents an integer in the range of 3 to 20.
  7. 7. The composition of claim 5, wherein a represents an integer in the range of 4 to 16.
  8. 8. The composition of claim 5, wherein b represents an integer in the range of 3 to 20.
  9. 9. The composition of claim 5, wherein b represents an integer in the range of 4 to 16.
  10. 10. The composition of any one of claims 1-4, wherein the inhibitor in (ii) has a weight average molecular weight (Mw) in the range of 600 g/mol to 4000 g/mol.
  11. 11. The composition of any one of claims 1-4, wherein the inhibitor in (ii) has a weight average molecular weight (Mw) in the range of 700 g to 3000 g per mole.
  12. 12. The composition of any one of claims 1-4, wherein the one or more inhibitors of (ii) are present in a total amount ranging from 10 mg/L to 1000mg/L based on the total volume of the acidic aqueous composition.
  13. 13. The composition of any one of claims 1-4, wherein the one or more inhibitors of (ii) are present in a total amount ranging from 50 mg/L to 700 mg/L based on the total volume of the acidic aqueous composition.
  14. 14. The composition of any one of claims 1-4, wherein the one or more inhibitors of (ii) are present in a total amount in the range of 70 mg/L to 500 mg/L based on the total volume of the acidic aqueous composition.
  15. 15. The composition of any one of claims 1-4, wherein the one or more inhibitors of (ii) are present in a total amount ranging from 80 mg/L to 400 mg/L based on the total volume of the acidic aqueous composition.
  16. 16. A method of electrolytic copper plating comprising the steps of: (a) A substrate suitable for electrolytic copper plating is provided or manufactured, (B) Contacting the substrate obtained after step (a) or after step (a) but after another step before step (b) with the acidic aqueous composition of any one of claims 1 to 15 and applying an electrical current such that the copper is electrolytically plated as a copper deposit on the substrate.
  17. 17. The method of claim 16, wherein the copper deposit forms a plurality of copper pillars and/or a plurality of copper conductive traces.
  18. 18. The method of claim 16 or 17, wherein the substrate comprises one or more recessed structures selected from the group consisting of trenches, microperforations, and vias.
  19. 19. A suppressor for electrodepositing copper deposits, it comprises the following items: a single N-heteroaromatic monocyclic ring comprising at least two ring nitrogen atoms and more than one substituent covalently linked to one of the ring nitrogen atoms and/or a ring carbon atom, wherein the substituents are independently or comprise: one or more linear or branched polyalkylene glycol moieties, and/or One or more than one linear or branched polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moiety, Provided that If the inhibitor comprises OH groups, it is the terminal OH groups of the polyalkylene glycol moiety, polyalkylene glycol block polyalkylene glycol and random polyalkylene glycol moiety, respectively, The inhibitor does not contain NH 2 group, halogen atom and sulfur atom, Wherein the inhibitor is selected from the group consisting of: , , (Ib), (If) , (Id), and (Ie) Wherein each is independently R represents a linear or branched polyalkylene glycol moiety or a linear or branched polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moiety and R 1 is alkyl, and N represents 0,1, 2,3,4 or 5, and Wherein the inhibitor in (ii) has a weight average molecular weight (Mw) in the range of 500 g/mol to 5000 g/mol.
  20. 20. A suppressor for electrodepositing copper deposit, consisting of: a single N-heteroaromatic monocyclic ring comprising at least two ring nitrogen atoms and more than one substituent covalently linked to one of the ring nitrogen atoms and/or a ring carbon atom, wherein the substituents are independently or comprise: one or more linear or branched polyalkylene glycol moieties, and/or One or more than one linear or branched polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moiety, Provided that If the inhibitor comprises OH groups, it is the terminal OH groups of the polyalkylene glycol moiety, polyalkylene glycol block polyalkylene glycol and random polyalkylene glycol moiety, respectively, The inhibitor does not contain NH 2 group, halogen atom and sulfur atom, Wherein the inhibitor is selected from the group consisting of: , , (Ib), (If) , (Id), and (Ie) Wherein each is independently R represents a linear or branched polyalkylene glycol moiety or a linear or branched polyalkylene glycol block polyalkylene glycol or random polyalkylene glycol moiety and R 1 is alkyl, and N represents 0,1, 2,3,4 or 5, and Wherein the inhibitor in (ii) has a weight average molecular weight (Mw) in the range of 500 g/mol to 5000 g/mol.

Description

Acidic aqueous composition for electrolytic deposition of copper deposits Technical Field The present invention relates to an acidic aqueous composition (electroplating bath) for electrolytic copper plating (electrodeposited copper), said composition comprising copper (II) ions, one or more than one inhibitor having the definition given below, a method of electrolytic copper plating using the acidic aqueous composition according to the invention, and specific inhibitors as defined above for electrodeposited copper deposits. The acidic aqueous composition according to the invention is suitable for the electrolytic deposition of copper, in particular for filling micro blind vias (BMV), through holes, trenches and similar structures. Thus, the method of the present invention is suitable for the manufacture of Printed Circuit Boards (PCBs), integrated Circuit (IC) substrates and the like, as well as for the metallization of semiconductor and glass substrates. Background Acidic aqueous compositions (aqueous acidic electroplating baths) for electrolytic copper plating (electrodeposited copper) are used to manufacture Printed Circuit Boards (PCBs) and IC substrates requiring the filling or stacking of fine structures such as trenches, through Holes (TH), blind Micro Vias (BMV), pillars and bumps with copper. Another application of these compositions is the filling of recessed structures such as Through Silicon Vias (TSVs) and Dual Damascene (DD) structures or features, electroplating or formation of redistribution layers (RDLs) and stud bumps. With the gradual miniaturization of printed circuit boards, design and complexity continue to increase. Generally, the goal is to increase computing power and/or functionality in a decreasing space. With this, the geometries of, for example, the conductor structures on or on the printed circuit board, the chip carrier and the semiconductor wafer become increasingly complex and complex. For example, the ratio of copper thickness to the width of the conductor path, or the ratio of hole depth to hole diameter (aspect ratio), in turn, continues to increase as the hole diameter becomes smaller and the conductor path becomes narrower. It is generally believed that structures exhibiting relatively high aspect ratios (e.g., 6:1 to 3:1) require complex electrolytic copper plating processes because these structures exhibit variable electrodeposition behavior. In particular, it has been shown in our own experiments that using methods known in the art to form uniform and reliable conductor structures in trenches and vias on printed circuit boards is inadequate and often very difficult in many cases. For example, copper layers with non-uniform surfaces are typically formed when depositing copper due to the relatively increased aspect ratio (and thus variable electrodeposition behavior) of the structure. However, non-uniform surfaces often lead to additional challenges during chemical/mechanical polishing after copper deposition. Typically, a prerequisite for the individual polishing steps is that the copper surface produced during the electrolytic deposition process is sufficiently smooth and uniform that the metal can be removed in a reliable manner up to the desired depth. Furthermore, a smooth and even surface helps to improve the level of reproducibility. It is well known to add a number of different organic additives to aqueous compositions for electrolytic copper plating to control the decorative and functional properties of copper coatings. So-called "inhibitors" may be used, which are typically polymeric organic species, such as high molecular weight polyethylene or polypropylene glycol, which strongly adsorb on the copper cathode surface to form a film, thereby dramatically increasing the overpotential for copper deposition. This prevents uncontrolled copper plating [.] "(see US 2005/0247777 A1, paragraph [0007 ]). Furthermore, anti-suppressors (also referred to as "accelerators") may be used with the aim of "counteracting the inhibitory effect of the suppressors and providing accelerated deposition within the substrate recess required for levelling" (see again US 2005/0247777 A1, paragraph [0007 ]). To obtain a structure filled with suitable copper, another organic additive may be generally used as a "leveler". "levelers" are typically nitrogen-containing organic compounds that tend to reduce the copper plating rate (see US 2005/0247777 A1, paragraph [0009 ]). JP 2013 023693A discloses a copper plating bath comprising an imidazole ring-bonded alkylene oxide compound having a ring at the end. The compound is believed to have good solubility in water and to provide high defoaming properties in the electroplating bath. The above mentioned additives typically positively affect the uniform deposition and metallization of copper during the electroplating process. It has been shown that in very small structures to be completely filled with copper, these additives generally help avoid