Electroplating copper solution for micro via fill

Abstract

The application discloses a kind of micro blind hole filling's electroplating copper solution, the electroplating copper solution includes the following mass concentration component: copper sulfate 50-90g / L, concentrated sulfuric acid 200g / L, chloride ion 50-70ppm, composite accelerator 20-80ppm, composite wetting agent 20-80ppm, composite leveling agent 10-40ppm, nucleating agent 10-40ppm, the rest is deionized water.The micro blind hole filling's electroplating copper solution provided in the application can realize the efficient electroplating filling hole of fine, high aspect ratio blind hole, and the filling hole process can be completed by direct current electroplating, with the advantages of low cost, high filling efficiency, low equipment requirement and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electroplating copper and relates to an electroplating copper solution for micro blind hole filling. BACKGROUND

[0002] In recent years, with the development of electronic products towards light, thin, short, small and multi-functional, especially the high integration of semiconductor chips and the rapid increase of I / O number and the rapid progress of high-density mounting technology, it is urgently required that the printed board has the characteristics of high density, high precision, high reliability and low cost. The conventional via interconnection cannot meet the requirements of high-density wiring and electronic products, and the blind hole interconnection technology has been widely used. There are three types of micro blind hole interconnection technology at present: one is the traditional hole plating technology; the second is the technology of filling with conductive glue (or resin material) after traditional copper plating; and the third is the micro blind hole electroplating copper filling technology. The micro blind hole electroplating copper filling technology can realize one-time completion of copper plating and hole filling and electrical interconnection, can improve the electrical performance and improve the connection reliability, and is superior to the conductive glue and resin material in terms of the conductivity and heat dissipation of the used copper material, and becomes an important method for realizing the interconnection of the printed board.

[0003] With the development of communication technology and the application of the Internet of Things, people's demand for the speed and efficiency of information exchange has greatly improved. For example, patents CN103361681A and CN102995076A all realize micro hole filling, but when the via becomes deeper and smaller, that is, the hole type is greater than 10:1, the market filling rate is less than 85%, which is difficult to meet the quality requirements of the thinnest copper thickness. Therefore, the present application provides a micro blind hole filling electroplating copper technology to solve this problem. SUMMARY

[0004] The electroplating copper solution provided by the present application can realize efficient electroplating hole filling of fine and high aspect ratio blind holes, and the hole filling process can be completed by direct current electroplating, which has the advantages of low cost, high hole filling efficiency and low equipment requirement.

[0005] The application discloses a micro blind hole filling electroplating copper solution, which comprises the following mass concentration components: copper sulfate 50-90 g / L, concentrated sulfuric acid 200 g / L, chloride ion 50-70 ppm, composite accelerator 20-80 ppm, composite wetting agent 20-80 ppm, composite leveling agent 10-40 ppm,

[0006] nucleating agent 10-40 ppm, and the balance is deionized water.

[0007] The chloride ion is provided by concentrated hydrochloric acid.

[0008] The composite accelerator is a mixture of sodium phenyldithiopropane sulfonate, sodium mercaptoimidazole propyl sulfonate and sodium dimethyl-dithioformamide sulfonate, the mass concentration ratio in use is 1:1:2, the mass concentration of sodium phenyldithiopropane sulfonate is 5-20ppm, the mass concentration of sodium mercaptoimidazole propyl sulfonate is 5-20ppm, and the mass concentration of sodium dimethyl-dithioformamide sulfonate is 10-40ppm.

[0009] The composite wetting agent is octyl decanol polyoxyethylene ether and decyne glycol polyether, the mass concentration ratio in use is 1:4, the mass concentration of octyl decanol polyoxyethylene ether is 4-16ppm, and the mass concentration of decyne glycol polyether is 16-64ppm.

[0010] The composite leveling agent is a polyethylene glycol, polypropylene glycol and polyvinyl pyrrolidone composite, the mass concentration ratio in use is 1:1:3, that is, the mass concentration of polyethylene glycol is 2-8ppm, the mass concentration of polypropylene glycol is 2-8ppm, and the mass concentration of polyvinyl pyrrolidone is 6-24ppm.

[0011] The nucleating agent is 5-fluorouracil.

[0012] The mass concentration ratio of the composite accelerator and the composite leveling agent in use is 2:1.

[0013] The mass concentration ratio of the composite wetting agent and the composite leveling agent in use is 2:1.

[0014] The mass concentration ratio of the nucleating agent and the composite leveling agent in use is 1:1.

[0015] The excellent effect of the present application is that, compared with the prior art, the present application provides a micro-blind-hole-filled copper electroplating solution, which has the following advantages:

[0016] 1) The composite accelerator provided by the present application can produce a synergistic effect with chloride ions, promote copper electrodeposition, and make the plating solution more easily enter the hole, thereby increasing the mass transfer effect.

[0017] 2) The composite wetting agent provided by the present application is beneficial to the ordered deposition of copper ions in a larger current density area, and it can improve the current density distribution by adsorbing on the cathode surface, thereby realizing uniform deposition.

[0018] 3) The mass concentration ratio of the composite wetting agent and the composite leveling agent in use is 2:1, and the wetting agent can cooperate with the leveling agent to improve the deep plating filling of the micro-blind-hole.

[0019] 4) The composite accelerator and the composite leveling agent can greatly improve the uniformity of the deposition rate inside and outside the hole, thereby realizing a deposition rate close to 1:1 between the hole and the copper surface. DETAILED DESCRIPTION

[0020] In order to make the present application clearer, further description will be given below by the text.

[0021] The application discloses a micro-blind-hole filling electroplating copper solution, which comprises the following mass concentration components: copper sulfate 50-90 g / L, concentrated sulfuric acid 200 g / L, chloride ion 50-70 ppm, composite accelerator 20-80 ppm, composite wetting agent 20-80 ppm, composite leveling agent 10-40 ppm, nucleating agent 10-40 ppm, and deionized water.

[0022] The chloride ion is provided by concentrated hydrochloric acid.

[0023] In the embodiment, the composite accelerator is a mixture of sodium phenyl dithiopropane sulfonate, sodium mercaptoimidazole propyl sulfonate and sodium dimethyl-dithioformamide sulfonate, and the mass concentration ratio of the three components is 1:1:2, that is, the mass concentration of sodium phenyl dithiopropane sulfonate is 5-20 ppm, the mass concentration of sodium mercaptoimidazole propyl sulfonate is 5-20 ppm, and the mass concentration of sodium dimethyl-dithioformamide sulfonate is 10-40 ppm.

[0024] In the embodiment, the composite wetting agent is octyl decanol polyoxyethylene ether and decyne glycol polyether, and the mass concentration ratio of the two components is 1:4, that is, the mass concentration of octyl decanol polyoxyethylene ether is 4-16 ppm, and the mass concentration of decyne glycol polyether is 16-64 ppm.

[0025] In the embodiment, the composite leveling agent is a composite of polyethylene glycol, polypropylene glycol and polyvinyl pyrrolidone, and the mass concentration ratio of the three components is 1:1:3, that is, the mass concentration of polyethylene glycol is 2-8 ppm, the mass concentration of polypropylene glycol is 2-8 ppm, and the mass concentration of polyvinyl pyrrolidone is 6-24 ppm.

[0026] In the embodiment, the nucleating agent is 5-fluorouracil.

[0027] In the embodiment, the mass concentration ratio of the composite accelerator to the composite leveling agent is 2:1.

[0028] In the embodiment, the mass concentration ratio of the composite wetting agent to the composite leveling agent is 2:1.

[0029] In the embodiment, the mass concentration ratio of the nucleating agent to the composite leveling agent is 1:1.

[0030] The application has the following advantages compared with the prior art.

[0031] 1) The composite accelerator provided by the application can produce a synergistic effect with the chloride ion, promote the electrodeposition of copper, and make the plating solution more easily enter the hole, thereby increasing the mass transfer effect.

[0032] 2) The composite wetting agent provided by the application is conducive to the ordered deposition of copper ions in a large current density area, and can improve the current density distribution by being adsorbed on the cathode surface, so that uniform deposition is achieved.

[0033] 3) The mass concentration ratio of the composite wetting agent and the composite leveler in use is 2:1, and the wetting agent can cooperate with the leveler to improve the deep plating filling of micro blind holes.

[0034] 4) The mass concentration ratio of the composite accelerator and the composite leveler in use is 2:1, which can greatly improve the uniformity of the deposition rate inside and outside the hole, so that the deposition rate of the hole and the copper surface is close to 1:1.

[0035] The experimental test evaluation grade standard is as follows:

[0036]

[0037] Example 1

[0038] Copper sulfate 70g / L, concentrated sulfuric acid 200g / L, chloride ion 60ppm, phenyl dithiopropane sulfonic acid sodium 10ppm, mercapto imidazole propyl sulfonic acid sodium 10ppm, dimethyl-dithioformamide sulfonic acid sodium 20ppm, octyl decanol polyoxyethylene ether 8ppm, decyne glycol polyether 32ppm, polyethylene glycol 4ppm, polypropylene glycol 4ppm, polyvinyl pyrrolidone 12ppm, 5-fluorouracil 20ppm.

[0039] The test is carried out on the Chuangzhi vertical wafer electroplating machine, the electroplating tank volume is 20L, the circulation amount is 12L / min, and the swing motor frequency is 25Hz. The electroplating process parameters are as follows: first segment 0 ASD standing for 1min, second segment 0.5 ASD electroplating for 10min, and third segment 1.5 ASD electroplating for 60min.

[0040] Example 2

[0041] Copper sulfate 80g / L, concentrated sulfuric acid 200g / L, chloride ion 50ppm, phenyl dithiopropane sulfonic acid sodium 5ppm, mercapto imidazole propyl sulfonic acid sodium 5ppm, dimethyl-dithioformamide sulfonic acid sodium 10ppm, octyl decanol polyoxyethylene ether 4ppm, decyne glycol polyether 16ppm, polyethylene glycol 2ppm, polypropylene glycol 2ppm, polyvinyl pyrrolidone 6ppm, 5-fluorouracil 10ppm.

[0042]

[0043] ​The test was carried out on the vertical wafer electroplating machine of Chuangzhi Technology, the electroplating tank volume was 20L, the circulation amount was 12L / min, and the swing motor frequency was 25Hz. The electroplating process parameters were as follows: 0 ASD standing for 1 min in the first stage, 0.5 ASD electroplating for 10 min in the second stage, and 1.5 ASD electroplating for 60 min in the third stage.

[0044] Example 3

[0045] Copper sulfate 70g / L, concentrated sulfuric acid 200g / L, chloride 70ppm, phenyl dithiopropane sulfonic acid sodium 20ppm, mercapto imidazole propyl sulfonic acid sodium 20ppm, dimethyl-dithioformamide sulfonic acid sodium 40ppm, octyl decanol polyoxyethylene ether 16ppm, decyne glycol polyether 64ppm, polyethylene glycol 8ppm, polypropylene glycol 8ppm, polyvinylpyrrolidone 24ppm, 5-fluorouracil 40ppm.

[0046] The test was carried out on the vertical wafer electroplating machine of Chuangzhi Technology, the electroplating tank volume was 20L, the circulation amount was 12L / min, and the swing motor frequency was 25Hz. The electroplating process parameters were as follows: 0 ASD standing for 1 min in the first stage, 0.5 ASD electroplating for 10 min in the second stage, and 1.5 ASD electroplating for 60 min in the third stage.

[0047] Comparative Example

[0048] Copper sulfate 70g / L, concentrated sulfuric acid 200g / L, chloride 70ppm, phenyl dithiopropane sulfonic acid sodium 20ppm, polyethylene glycol 8ppm.

[0049] The test was carried out on the vertical wafer electroplating machine of Chuangzhi Technology, the electroplating tank volume was 20L, the circulation amount was 12L / min, and the swing motor frequency was 25Hz. The electroplating process parameters were as follows: 0 ASD standing for 1 min in the first stage, 0.5 ASD electroplating for 10 min in the second stage, and 1.5 ASD electroplating for 60 min in the third stage.

[0050] Five pieces of substrate were taken for each example to form a group, and the data obtained were as follows:

[0051]

[0052]

[0053] Through the above comparison, the comparative example lacks mercapto imidazole propyl sulfonic acid sodium, dimethyl-dithioformamide sulfonic acid sodium, octyl decanol polyoxyethylene ether, decyne glycol polyether, polypropylene glycol, polyvinylpyrrolidone, and 5-fluorouracil compared with the examples. The results of the examples are all excellent in hole filling ability, uniformity, and hole orifice fracture; while the deep plating ability, hole filling ability, uniformity, and hole orifice fracture of the comparative example are poor.

[0054] The above disclosed are only embodiments of the present application, but the present application is not limited thereto, and any changes that can be thought of by those skilled in the art shall fall within the protection scope of the present application.

Claims

1. A micro via fill electroplating copper solution characterized by, The electroplating copper solution comprises the following mass concentration components: copper sulfate 50-90 g / L, concentrated sulfuric acid 200 g / L, chloride ion 50-70 ppm, composite accelerator 20-80 ppm, composite wetting agent 20-80 ppm, composite leveling agent 10-40 ppm, nucleating agent 10-40 ppm, and the balance is deionized water, and the chloride ion is provided by concentrated hydrochloric acid; The composite accelerator is a mixture of sodium phenyldithiopropane sulfonate, sodium mercaptoimidazole propyl sulfonate, and sodium dimethyl-dithioformamide sulfonate, and the mass concentration ratio thereof when used is 1:1:2, the mass concentration of sodium phenyldithiopropane sulfonate is 5-20 ppm, the mass concentration of sodium mercaptoimidazole propyl sulfonate is 5-20 ppm, and the mass concentration of sodium dimethyl-dithioformamide sulfonate is 10-40 ppm; the composite wetting agent is octyl decanol polyoxyethylene ether and decyne glycol polyether, and the mass concentration ratio thereof when used is 1:4, the mass concentration of octyl decanol polyoxyethylene ether is 4-16 ppm, and the mass concentration of decyne glycol polyether is 16-64 ppm; the composite leveling agent is a polyethylene glycol, polypropylene glycol, and polyvinylpyrrolidone composite, and the mass concentration ratio thereof when used is 1:1:3, the mass concentration of polyethylene glycol is 2-8 ppm, the mass concentration of polypropylene glycol is 2-8 ppm, and the mass concentration of polyvinylpyrrolidone is 6-24 ppm; and the nucleating agent is 5-fluorouracil.

2. A micro via fill electroplating copper solution according to claim 1, wherein, The mass concentration ratio of the composite accelerator to the composite leveling agent when used is 2:

1.

3. A microvia fill electroplated copper solution according to claim 1, wherein, The mass concentration ratio of the composite wetting agent to the composite leveling agent when used is 2:

1.

4. The microvia fill electroplated copper solution of claim 1 wherein, The mass concentration ratio of the nucleating agent to the composite leveling agent when used is 1:

1. The mass concentration ratio of the nucleating agent to the composite leveling agent when used is 1:1.

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