Treatment method after plating with Sn or Sn alloy

Abstract

To provide a treatment method for preventing dirt of a chemical compound of Sn or a Sn alloy deposited on a substrate, a conveyance jig, etc. from accumulating after plating with the Sn or the Sn alloy.SOLUTION: In a treatment method after plating with Sn or a Sn alloy, at least one of the members to be used in a series of plating treatments is cleaned by an acidic solution, which is 5 or less in pH, containing an acid and / or its salt immediately after the plating.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a treatment method after plating with Sn or a Sn alloy, and in particular to a treatment method for members used in a series of plating processes, such as substrates such as wafers, printed circuit boards, and transport jigs for these substrates, to prevent the accumulation of compound stains of Sn or a Sn alloy that have precipitated on the members after plating with Sn or a Sn alloy. [Background technology]

[0002] Generally, after plating a substrate with various metals or alloys, the plating solution and contaminants adhering to the substrate are washed off with water or hot water.

[0003] However, after Sn and Sn alloy plating, compound stains of Sn and Sn alloys accumulate, which cannot be removed by the above-mentioned general cleaning methods, and cause plating spread on the plating equipment and transport jigs, and the compound stains themselves on the substrate become a problem. Therefore, it becomes necessary to frequently replace the parts used in the plating process or to remove the stains using special cleaning methods, which reduces work efficiency and imposes a large burden in terms of cost.

[0004] Therefore, various methods have been proposed for cleaning and removing post-plating contamination using improved plating equipment.

[0005] For example, Patent Document 1 describes an automatic wafer plating apparatus equipped with a load stage, an orientation stage, a plating stage, a recovery stage, and a cleaning stage, and describes a method in which, using this plating apparatus, wafers are transported in sequence from the load stage to the cleaning stage, and the wafers that have been plated at the plating stages along the way are cleaned in the final stage, the cleaning stage.

[0006] Patent Document 2 describes a face-up plating apparatus having a plating tank with an opening on the bottom surface and a substrate holder that supports the back surface of a substrate to be processed and is movable so that the opening is covered by the substrate to be processed. The patent document also describes a cleaning method in which a cleaning liquid is sprayed onto the back surface of a substrate to be processed during the process of moving the substrate to be processed from the holder that supports the back surface of the substrate, the front surface of which has been plated in the plating apparatus. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 3583883 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-009051 Summary of the Invention [Problem to be solved by the invention]

[0008] In the method described in Patent Document 1, it is expected that a general cleaning solution, i.e., water or hot water, will be used in the final cleaning stage, and if such a cleaning stage is applied to Sn or Sn alloy plating treatment, the first cleaning alone will be insufficient, and the deposited Sn or Sn alloy compound contamination will accumulate, which may cause plating wear on the plating equipment, transport jigs, etc. Therefore, to eliminate this risk, it is necessary to frequently replace transport jigs, etc., or to adopt a special cleaning method.

[0009] In the cleaning method described in Patent Document 2, although the substrate itself, such as a wafer, can be cleaned, the transport jig for the substrate is not sufficiently cleaned, and there is a risk that plating may spread to the transport jig in the future. Therefore, to eliminate this risk, it is necessary to frequently replace the transport jig or to employ a special cleaning method.

[0010] The present invention has been made in view of the above-mentioned conventional problems, and its object is to provide a treatment method for easily and effectively preventing the accumulation of Sn or Sn alloy compound stains deposited on substrates such as wafers, transport jigs, etc. after Sn or Sn alloy plating. [Means for solving the problem]

[0011] In order to achieve the above object, the inventors have conducted extensive research and found that by washing the substrate, transport jig, etc. with a specific acidic solution immediately after plating with Sn or an Sn alloy, it is possible to easily and effectively prevent the accumulation of compound stains of the precipitated Sn or Sn alloy, and have completed the present invention.

[0012] Specifically, the treatment method after plating with Sn or an Sn alloy of the present invention is characterized in that immediately after the plating, at least one of the members used in the series of plating treatments is washed with an acidic solution containing an acid and / or a salt thereof and having a pH of 5 or less.

[0013] In the treatment method of the present invention, immediately after plating with Sn or an Sn alloy, a component on which Sn or Sn alloy compound stains have been deposited is washed with an acidic solution containing an acid and / or its salt and having a pH of 5 or less. As described below, in the treatment method of the present invention, the component can be washed with normal water or hot water and dried after plating. However, even if washing with water or hot water or drying is performed, washing with the acidic solution is performed before washing with water or hot water or drying, i.e., immediately after plating. In this manner, the treatment method of the present invention sequentially performs plating, followed by washing with an acidic solution, and optionally washing with water or hot water and drying. This differs from conventional cleaning methods that simply use general cleaning solutions such as water or hot water, or cleaning methods that target only specific components to be plated, and therefore easily and effectively prevents the accumulation of deposited Sn or Sn alloy compound stains on various components used in a series of plating processes.

[0014] In the processing method of the present invention, when the member is a substrate and its transport jig, it is preferable to perform cleaning with the acidic solution while the substrate remains fixed to the transport jig. By performing cleaning with the acidic solution while the substrate remains fixed to the transport jig in this manner, cleaning of the transport jig, which has conventionally been complicated and / or insufficient, can be performed easily and sufficiently.

[0015] In the treatment method of the present invention, the acid and / or salt thereof contained in the acidic solution is preferably one or more organic acids and / or salts thereof. By cleaning the component with an acidic solution containing an organic acid and / or salt thereof, accumulation of deposited Sn or Sn alloy compound stains can be more effectively prevented.

[0016] In the treatment method of the present invention, the content of the acid and / or its salt in the acidic solution is preferably 8 g / L to 700 g / L. By cleaning the component with an acidic solution whose content of the acid and / or its salt is adjusted to fall within this range, it is possible to more effectively prevent the accumulation of deposits of Sn or Sn alloy compounds.

[0017] In the treatment method of the present invention, the acidic solution preferably contains one or more complexing agents and / or chelating agents. By cleaning the component with an acidic solution further containing a complexing agent and / or a chelating agent, accumulation of deposited Sn or Sn alloy compound stains can be more effectively prevented.

[0018] In the treatment method of the present invention, the acidic solution preferably contains one or more nonionic or ionic surfactants. By cleaning the component with an acidic solution further containing a nonionic or ionic surfactant, accumulation of deposited Sn or Sn alloy compound stains can be more effectively prevented. [Effects of the Invention]

[0019] According to the treatment method of the present invention, after Sn or Sn alloy plating, it is possible to easily and effectively prevent the accumulation of Sn or Sn alloy compound stains that have precipitated on components used in a series of plating processes, such as substrates such as wafers, printed circuit boards, and transfer jigs for these substrates. Therefore, according to the treatment method of the present invention, it is not necessary to frequently replace components used in plating processes or to remove stains using special cleaning methods, as in the conventional cases, and it is possible to sufficiently prevent a decrease in work efficiency and an increase in cost burden. DETAILED DESCRIPTION OF THE INVENTION

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following description of preferred embodiments is merely exemplary in nature and is not intended to limit the present invention, its application, or its uses.

[0021] In the treatment method after plating with Sn or an Sn alloy of the present invention, at least one of the members used in the series of plating treatments is washed with a specific acid solution immediately after the plating.

[0022] The specific acidic solution used in the treatment method of the present invention contains an acid and / or its salt and has a pH of 5 or less. By using such a specific acidic solution and performing washing immediately after plating, it is possible to easily and effectively prevent the accumulation of stains caused by compounds of deposited Sn or Sn alloys, which is not possible with conventional washing with water or hot water.

[0023] The acid contained in the acidic solution is not particularly limited, and examples thereof include organic acids such as organic sulfonic acids (e.g., methanesulfonic acid, ethanesulfonic acid, 2-propanolsulfonic acid, sulfosuccinic acid, and p-phenolsulfonic acid), organic acids (e.g., acetic acid, formic acid, oxalic acid, tartaric acid, citric acid, and glyoxylic acid), inorganic acids (e.g., sulfuric acid, hydrochloric acid, phosphoric acid, phosphorous acid, hypophosphorous acid, sulfamic acid, and nitric acid), and salts thereof, which can be used alone or in combination of two or more. Among these, the acid and / or salt thereof contained in the acidic solution is preferably one or more organic acids and / or salts thereof, in order to more effectively prevent the accumulation of deposited Sn or Sn alloy compound stains.

[0024] The pH of the acidic solution is 5 or less, preferably 2 or less, and more preferably a strong acid solution with a pH of 1 or less. If the pH of the acidic solution exceeds the upper limit, there is no difference between the acidic solution and water or hot water, and the accumulation of deposited Sn or Sn alloy compound stains cannot be effectively prevented.

[0025] The content of the acid and / or its salt in the acidic solution is preferably 8 g / L to 700 g / L, more preferably 10 g / L to 650 g / L. If the content of the acid and / or its salt is below the lower limit, the accumulation of precipitated Sn or Sn alloy compound stains may not be effectively prevented. If the content of the acid and / or its salt is above the upper limit, the solubility may be exceeded, causing recrystallization and the deposition of new stains, or the acid concentration may become too high, damaging the plating film.

[0026] The acidic solution preferably contains one or more complexing agents and / or chelating agents. By cleaning the component with an acidic solution containing the acid and / or its salt as well as the complexing agent and / or chelating agent, it is possible to more effectively prevent the accumulation of deposits of Sn or Sn alloy compounds.

[0027] Examples of the complexing agent include gluconic acid, glycine, citric acid, malic acid, glucoheptonic acid, gluconolactone, glucoheptolactone, succinic acid, malonic acid, tartaric acid, oxalic acid, erythorbic acid, sorbic acid, ascorbic acid, pyrophosphoric acid, and salts thereof.

[0028] Examples of the chelating agent include ethylenediamine, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), nitrilotriacetic acid (NTA), iminodiacetic acid (IDA), iminodipropionic acid (IDP), hydroxyethylethylenediaminetriacetic acid (HEDTA), triethylenetetraminehexaacetic acid (TTHA), 1,3-propanediamine-N,N,N',N'-tetraacetic acid (PDTA), 1,3-diamino-2-hydroxypropanol-N,N,N',N'-tetraacetic acid (DPTA), N-(2-hydroxyethyl)iminodiacetic acid (HIDA), N,N-bis(2-hydroxyethyl)glycine (DHEG), glycol ether diaminetetraacetic acid (GEDTA), ethylenediamine-N,N'-disuccinic acid (EDDS), and salts thereof.

[0029] The content of the complexing agent and / or chelating agent in the acidic solution is preferably 1 g / L to 30 g / L, more preferably 2 g / L to 25 g / L. If the content of the complexing agent and / or chelating agent is below the lower limit, the effect of preventing the accumulation of precipitated Sn or Sn alloy compound stains may not be sufficiently improved. If the content of the complexing agent and / or chelating agent is above the upper limit, recrystallization may occur due to the solubility being exceeded, and new stains may be deposited.

[0030] The acidic solution preferably contains one or more nonionic surfactants or ionic surfactants. By cleaning the component with an acidic solution containing the acid and / or its salt together with a nonionic surfactant or an ionic surfactant, it is possible to more effectively prevent the accumulation of deposits of Sn or Sn alloy compounds.

[0031] Examples of the nonionic surfactant include C1 to C 20 Alkanols, phenols, naphthols, bisphenols, C1-C 25 Alkylphenols, aryl alkylphenols, C1-C 25 Alkyl naphthols, C1-C 25 Alkoxyl phosphate (salt), sorbitan ester, polyalkylene glycol, C1-C 22 Examples include those obtained by addition condensation of ethylene oxide (EO) and / or propylene oxide (PO) with aliphatic amides.

[0032] Examples of the ionic surfactant include anionic surfactants such as alkyl sulfates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkyl phenyl ether sulfates, alkyl benzene sulfonates, and alkyl naphthalene sulfonates, and cationic surfactants such as mono- to tri-alkylamine salts, dimethyldialkylammonium salts, and trimethylalkylammonium salts.

[0033] The content of the nonionic surfactant or ionic surfactant in the acidic solution is preferably 1 g / L to 30 g / L, more preferably 2 g / L to 25 g / L. If the content of the nonionic surfactant or ionic surfactant is below the lower limit, the effect of preventing the accumulation of deposited Sn or Sn alloy compound stains may not be sufficiently improved. If the content of the nonionic surfactant or ionic surfactant is above the upper limit, a large amount of the nonionic surfactant or ionic surfactant may remain deposited on the component even after the subsequent cleaning process, which may adversely affect the subsequent process.

[0034] The specific acidic solution used in the treatment method of the present invention may contain, in addition to the acid and / or its salt, the complexing agent and / or chelating agent, and the nonionic surfactant or ionic surfactant, various other additives such as a smoothing agent, a preservative, an antifoaming agent, and an antifungal agent, as necessary.

[0035] The method for preparing the acidic solution is not particularly limited. For example, the acid and / or its salt, and, if necessary, the complexing agent and / or chelating agent, the nonionic surfactant or ionic surfactant, and various other additives may be appropriately selected, and the contents of each of the components in the acidic solution may be adjusted to fall within the above-mentioned ranges so that the pH of the acidic solution falls within the above-mentioned ranges, and the components may be dissolved in distilled water or the like.

[0036] In the treatment method of the present invention, the member to be cleaned with the acidic solution is not particularly limited as long as it is a member used in a series of plating processes using Sn or Sn alloys, but it may be, for example, a substrate such as a wafer or a printed circuit board, a transport jig for these substrates, contact parts of these substrates, or a non-conductive member for protecting the contact parts, which may be subject to the deposition and accumulation of Sn or Sn alloy compound contaminants. In particular, transport jigs are prone to the deposition of Sn or Sn alloy compound contaminants, and conventional methods have not been able to prevent this accumulation. However, the treatment method of the present invention can easily and effectively prevent this accumulation.

[0037] In the treatment method of the present invention, when the member is, for example, a substrate such as a wafer or a printed circuit board, or a transport jig for these substrates, it is preferable to perform cleaning with the acidic solution while the substrate remains fixed to the transport jig. By performing cleaning while the substrate remains fixed to the transport jig in this manner, Sn or Sn alloy compound stains deposited on both the transport jig and the substrate can be simultaneously and easily removed, and the accumulation of deposited Sn or Sn alloy compound stains can be effectively prevented, especially in transport jigs on which deposited Sn or Sn alloy compound stains are likely to accumulate.

[0038] The method for washing the component with the acidic solution is not particularly limited, and examples thereof include a method of immersing the component in an acidic solution at about 20°C to 60°C for about 0.5 minutes to 3 minutes, a method of spraying the acidic solution onto the component using a spray method, and a method of bringing the component into contact with the acidic solution using a shower method.

[0039] In the treatment method of the present invention, the member is washed with an acidic solution immediately after plating with Sn or an Sn alloy. As described above, washing with the acidic solution may be followed by washing with water or warm water and drying.

[0040] The conditions and method for washing with water or warm water are not particularly limited. For example, a method of immersing the component in water at about 20°C to 35°C or warm water at about 35°C to 60°C for about 0.5 to 3 minutes, or a method of spraying the component with a spray method or showering the component in contact with the component, as in the case of washing with the acid solution, can be used.

[0041] There are no particular limitations on the conditions and method for drying, and for example, a method can be employed in which the member is dried at about 20°C to 150°C using cold air, hot air, compressed air, or the like.

[0042] In the present invention, the series of plating steps using Sn or Sn alloys is not particularly limited, and conventional plating steps can be used. The Sn plating bath used for plating may contain a soluble tin salt, such as a tin salt of an organic sulfonic acid (e.g., methanesulfonic acid, ethanesulfonic acid, 2-propanolsulfonic acid, sulfosuccinic acid, or p-phenolsulfonic acid), an acid or its salt, and various additives, such as an antioxidant, a stabilizer, a complexing agent, a surfactant, a brightener, a leveling agent, a pH adjuster, a conductive salt, or a preservative, as needed. The Sn alloy plating bath used for plating may be the Sn plating bath described above, further containing a soluble metal salt, such as a soluble silver salt, a soluble copper salt, a soluble bismuth salt, or a soluble indium salt. Furthermore, plating may be performed by electroplating or electroless plating, and the plating conditions for each method are not particularly limited. [Example]

[0043] Examples and comparative examples are given below to explain in detail the treatment method after plating with Sn or an Sn alloy according to the present invention. Among Examples 1 to 18, Examples 1, 4 to 7 and 9 to 16 are reference examples.

[0044] <Reference example> (1) Reference Example 1: Sn plating An electrolytic Sn plating bath was prepared with the following composition. The plating conditions are also shown below. [Plating bath composition] Stannous methanesulfonate (Sn 2+ as): 60g / L Methanesulfonic acid (as free acid): 150g / L 1-(2-dimethylaminoethyl)-5-mercaptotetrazole: 2g / L 3,6-dithiaoctane-1,8-diol: 2g / L Bisphenol A polyethoxylate (EO 13 moles): 10g / L Catechol: 5g / L [Plating conditions] Bath temperature: 30℃ Cathode current density: 1.0A / dm 2 Plating time: Approximately 1800 seconds

[0045] (2) Reference Example 2: Sn-Ag alloy plating An Sn-Ag alloy electroplating bath was prepared with the following composition. The plating conditions are also shown below. [Plating bath composition] Stannous methanesulfonate (Sn 2+ as): 60g / L Silver methanesulfonate (Ag + as): 0.8g / L Methanesulfonic acid (as free acid): 150g / L 1-(2-dimethylaminoethyl)-5-mercaptotetrazole: 2g / L 3,6-dithiaoctane-1,8-diol: 2g / L Bisphenol A polyethoxylate (EO 13 moles): 10g / L Catechol: 5g / L [Plating conditions] Bath temperature: 30℃ Cathode current density: 1.0A / dm 2 Plating time: Approximately 1800 seconds

[0046] <Examples and Comparative Examples> (1) Example 1 An acidic solution was prepared with the following composition: Next, the following steps 1 to 7 were repeated 30 times. [Acidic solution composition] Methanesulfonic acid: 100g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 1) Step 4: Washing with an acidic solution (25°C, immersion for 1 minute) Step 5: Wash with warm water (50°C, immersion for 0.5 minutes) Step 6: Drying (60°C, 0.5 minutes) Step 7: Removing the wafer from the transfer jig

[0047] (2) Example 2 An acidic solution was prepared with the following composition: Next, the following steps 1 to 7 were repeated 30 times. [Acidic solution composition] Methanesulfonic acid: 100g / L Gluconic acid: 5g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 1) Step 4: Washing with an acidic solution (50°C, immersion for 1 minute) Step 5: Wash with warm water (50°C, immersion for 0.5 minutes) Step 6: Drying (60°C, 0.5 minutes) Step 7: Removing the wafer from the transfer jig

[0048] (3) Example 3 An acidic solution was prepared with the following composition: Next, the following steps 1 to 7 were repeated 30 times. [Acidic solution composition] Methanesulfonic acid: 100g / L Glycine: 10g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 1) Step 4: Washing with an acidic solution (50°C, immersion for 1 minute) Step 5: Wash with warm water (50°C, immersion for 0.5 minutes) Step 6: Drying (60°C, 0.5 minutes) Step 7: Removing the wafer from the transfer jig

[0049] (4) Example 4 An acidic solution was prepared with the following composition: Next, the following steps 1 to 7 were repeated 30 times. [Acidic solution composition] Methanesulfonic acid: 100g / L Citric acid: 20g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 1) Step 4: Washing with an acidic solution (50°C, immersion for 1 minute) Step 5: Wash with warm water (50°C, immersion for 0.5 minutes) Step 6: Drying (60°C, 0.5 minutes) Step 7: Removing the wafer from the transfer jig

[0050] (5) Example 5 An acidic solution was prepared with the following composition: Next, the following steps 1 to 7 were repeated 30 times. [Acidic solution composition] Methanesulfonic acid: 100g / L EDTA: 8g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 1) Step 4: Washing with an acidic solution (50°C, immersion for 1 minute) Step 5: Wash with warm water (50°C, immersion for 0.5 minutes) Step 6: Drying (60°C, 0.5 minutes) Step 7: Removing the wafer from the transfer jig

[0051] (6) Example 6 An acidic solution was prepared with the following composition: Next, the following steps 1 to 7 were repeated 30 times. [Acidic solution composition] Methanesulfonic acid: 250g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 1) Step 4: Washing with an acidic solution (50°C, immersion for 1 minute) Step 5: Wash with warm water (50°C, immersion for 0.5 minutes) Step 6: Drying (60°C, 0.5 minutes) Step 7: Removing the wafer from the transfer jig

[0052] (7) Example 7 An acidic solution was prepared with the following composition: Next, the following steps 1 to 7 were repeated 30 times. [Acidic solution composition] Methanesulfonic acid: 500g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 1) Step 4: Washing with an acidic solution (50°C, immersion for 1 minute) Step 5: Wash with warm water (50°C, immersion for 0.5 minutes) Step 6: Drying (60°C, 0.5 minutes) Step 7: Removing the wafer from the transfer jig

[0053] (8) Example 8 An acidic solution was prepared with the following composition: Next, the following steps 1 to 7 were repeated 30 times. [Acidic solution composition] Methanesulfonic acid: 100g / L Sodium gluconate: 10g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 1) Step 4: Washing with an acidic solution (50°C, immersion for 1 minute) Step 5: Wash with warm water (50°C, immersion for 0.5 minutes) Step 6: Drying (60°C, 0.5 minutes) Step 7: Removing the wafer from the transfer jig

[0054] (9) Example 9 An acidic solution was prepared with the following composition: Next, the following steps 1 to 7 were repeated 30 times. [Acidic solution composition] Methanesulfonic acid: 100g / L Sodium malate: 10g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 1) Step 4: Washing with an acidic solution (50°C, immersion for 1 minute) Step 5: Wash with warm water (50°C, immersion for 0.5 minutes) Step 6: Drying (60°C, 0.5 minutes) Step 7: Removing the wafer from the transfer jig

[0055] (10) Example 10 An acidic solution was prepared with the following composition: Next, the following steps 1 to 7 were repeated 30 times. [Acidic solution composition] Methanesulfonic acid: 100g / L NTA: 10g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 1) Step 4: Washing with an acidic solution (50°C, immersion for 1 minute) Step 5: Wash with warm water (50°C, immersion for 0.5 minutes) Step 6: Drying (60°C, 0.5 minutes) Step 7: Removing the wafer from the transfer jig

[0056] (11) Example 11 An acidic solution was prepared with the following composition: Next, the following steps 1 to 7 were repeated 30 times. [Acidic solution composition] Methanesulfonic acid: 100g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 2) Step 4: Washing with an acidic solution (50°C, immersion for 1 minute) Step 5: Wash with warm water (50°C, immersion for 0.5 minutes) Step 6: Drying (60°C, 0.5 minutes) Step 7: Removing the wafer from the transfer jig

[0057] (12) Example 12 An acidic solution was prepared with the following composition: Next, the following steps 1 to 7 were repeated 30 times. [Acidic solution composition] Methanesulfonic acid: 600g / L Polyvinylpyrrolidone: 20g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 2) Step 4: Washing with an acidic solution (50°C, immersion for 1 minute) Step 5: Wash with warm water (50°C, immersion for 0.5 minutes) Step 6: Drying (60°C, 0.5 minutes) Step 7: Removing the wafer from the transfer jig

[0058] (13) Example 13 An acidic solution was prepared with the following composition: Next, the following steps 1 to 7 were repeated 30 times. [Acidic solution composition] Methanesulfonic acid: 10g / L Polyethylene glycol (average molecular weight 1000): 20g / L EDTA: 20g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 2) Step 4: Washing with an acidic solution (50°C, immersion for 1 minute) Step 5: Wash with warm water (50°C, immersion for 0.5 minutes) Step 6: Drying (60°C, 0.5 minutes) Step 7: Removing the wafer from the transfer jig

[0059] (14) Example 14 An acidic solution was prepared with the following composition: Next, the following steps 1 to 7 were repeated 30 times. [Acidic solution composition] Sulfuric acid: 100g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 1) Step 4: Washing with an acidic solution (50°C, immersion for 1 minute) Step 5: Wash with warm water (50°C, immersion for 0.5 minutes) Step 6: Drying (60°C, 0.5 minutes) Step 7: Removing the wafer from the transfer jig

[0060] (15) Example 15 An acidic solution was prepared with the following composition: Next, the following steps 1 to 7 were repeated 30 times. [Acidic solution composition] Sulfuric acid: 100g / L EDTA: 20g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 1) Step 4: Washing with an acidic solution (50°C, immersion for 1 minute) Step 5: Wash with warm water (50°C, immersion for 0.5 minutes) Step 6: Drying (60°C, 0.5 minutes) Step 7: Removing the wafer from the transfer jig

[0061] (16) Example 16 An acidic solution was prepared with the following composition: Next, the following steps 1 to 7 were repeated 30 times. [Acidic solution composition] Methanesulfonic acid: 100g / L Alkyldimethylaminopropylamide: 10g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 1) Step 4: Washing with an acidic solution (50°C, immersion for 1 minute) Step 5: Wash with warm water (50°C, immersion for 0.5 minutes) Step 6: Drying (60°C, 0.5 minutes) Step 7: Removing the wafer from the transfer jig

[0062] (17) Example 17 An acidic solution was prepared with the following composition: Next, the following steps 1 to 7 were repeated 30 times. [Acidic solution composition] Methanesulfonic acid: 100g / L Benzalkonium chloride: 5g / L Gluconic acid: 10g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 1) Step 4: Washing with an acidic solution (50°C, immersion for 1 minute) Step 5: Wash with warm water (50°C, immersion for 0.5 minutes) Step 6: Drying (60°C, 0.5 minutes) Step 7: Removing the wafer from the transfer jig

[0063] (18) Example 18 An acidic solution was prepared with the following composition: Next, the following steps 1 to 7 were repeated 30 times. [Acidic solution composition] Sodium methanesulfonate: 100g / L Methanesulfonic acid: 5g / L Gluconic acid: 10g / L pH: 3.5 [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 1) Step 4: Washing with an acidic solution (50°C, immersion for 1 minute) Step 5: Wash with warm water (50°C, immersion for 0.5 minutes) Step 6: Drying (60°C, 0.5 minutes) Step 7: Removing the wafer from the transfer jig

[0064] (19) Comparative Example 1 The following steps 1 to 6 were repeated 30 times. [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 1) Step 4: Wash with water (25°C, immersion for 1 minute) Step 5: Drying (60°C, 1 minute) Step 6: Removing the wafer from the transfer jig

[0065] (20) Comparative Example 2 An acidic solution was prepared with the following composition: Next, the following steps 1 to 8 were repeated 30 times. [Acidic solution composition] Methanesulfonic acid: 100g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 1) Step 4: Wash with water (25°C, immersion for 0.5 minutes) Step 5: Washing with an acidic solution (50°C, immersion for 1 minute) Step 6: Wash with water (25°C, immersion for 0.5 minutes) Step 7: Drying (60°C, 0.5 minutes) Step 8: Removing the wafer from the transfer jig

[0066] (21) Comparative Example 3 An acidic solution was prepared with the following composition: Next, the following steps 1 to 9 were repeated 30 times. [Acidic solution composition] Methanesulfonic acid: 100g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 1) Step 4: Wash with water (25°C, immersion for 0.5 minutes) Step 5: Drying (60°C, 0.5 minutes) Step 6: Removing the wafer from the transfer jig Step 7: Washing with an acidic solution (50°C, immersion for 1 minute) Step 8: Wash with water (25°C, immersion for 0.5 minutes) Step 9: Drying (60°C, 0.5 minutes)

[0067] (22) Comparative Example 4 An acidic solution was prepared with the following composition: Next, the following steps 1 to 8 were repeated 30 times. [Acidic solution composition] Methanesulfonic acid: 100g / L pH: 1 or less [Process] Step 1: Fixing the wafer on the transfer jig Step 2: Wash with water (room temperature 20-30°C, immersion for 0.5 minutes) Process 3: Plating (Reference Example 2) Step 4: Wash with water (25°C, immersion for 0.5 minutes) Step 5: Washing with an acidic solution (50°C, immersion for 1 minute) Step 6: Wash with water (25°C, immersion for 0.5 minutes) Step 7: Drying (60°C, 0.5 minutes) Step 8: Removing the wafer from the transfer jig

[0068] <Test example> For the transport jigs that had undergone each process in Examples 1 to 18 and Comparative Examples 1 to 4, the surfaces were observed using a field emission scanning electron microscope (FE-SEM, 50K magnification, S-4800, manufactured by Hitachi High-Technologies Corporation). The observation area was divided into 4 × 5 squares, and the coverage of the transport jig surface with Sn or Sn alloy compound soiling was calculated as [(number of squares with attached dirt particles / total number of squares) × 100 (%)], and the prevention of the accumulation of the compound soiling was evaluated. The results are shown in Table 1.

[0069] [Table 1]

[0070] As shown in Table 1, in Examples 1 to 18, the wafer and transport jig were washed with an acidic solution containing an acid immediately after plating with Sn or an Sn alloy according to the processing method of the present invention. Even after the plating and washing with the acidic solution were repeated 30 times, the coverage of the transport jig surface with Sn or Sn alloy compound stains was low at 0% to 30%, and the accumulation of the compound stains was sufficiently prevented.

[0071] On the other hand, in Comparative Examples 1 to 4, cleaning with an acidic solution was not performed (Comparative Example 1), or cleaning with an acidic solution was performed not immediately after plating with Sn or an Sn alloy, but immediately after washing with water (Comparative Examples 2 and 4), or after washing with water and drying (Comparative Example 3), and Sn or Sn alloy compound stains accumulated over the entire surface of the transport jig.

[0072] As in Example 1, in which cleaning was performed with an acidic solution containing only an organic acid, in Examples 2 to 5, 8 to 10, and 18, in which cleaning was performed with an acidic solution containing a complexing agent and / or a chelating agent in addition to an organic acid, the coverage of the surface of the transport jig with Sn compound stains was low, at 0% to 30%, and the accumulation of the compound stains was sufficiently prevented.

[0073] Compared to Example 1, in which cleaning was performed with an acidic solution containing only an organic acid, in Example 16, in which cleaning was performed with an acidic solution containing an organic acid and a surfactant, and in Example 17, in which cleaning was performed with an acidic solution containing an organic acid, a complexing agent, and a surfactant, the coverage of the conveying jig surface with Sn compound stains was 0%, and the accumulation of the compound stains was completely prevented.

[0074] Even when plating with Sn—Ag alloy was performed as in Examples 11 to 13, by washing immediately after plating with an acidic solution containing only an organic acid (Example 11), an acidic solution containing an organic acid and a surfactant (Example 12), or an acidic solution containing an organic acid, a complexing agent, and a surfactant (Example 13), the coverage of the surface of the conveying jig with Sn—Ag alloy compound stains was low at 5% to 30%, and the accumulation of the compound stains was sufficiently prevented.

[0075] As in Examples 14 and 15, even when cleaning was performed immediately after plating with an acidic solution containing only inorganic acid (Example 14) or an acidic solution containing a complexing agent in addition to inorganic acid (Example 15), the coverage of the surface of the transport jig with Sn compound stains was low at 5% to 30%, and the accumulation of the compound stains was sufficiently prevented. [Industrial Applicability]

[0076] According to the treatment method after plating with Sn or Sn alloy of the present invention, it is possible to easily and effectively prevent the accumulation of Sn or Sn alloy compound stains deposited on a substrate, a transport jig, etc. Therefore, the treatment method of the present invention can be suitably used in a series of plating treatment steps with Sn or Sn alloy.

Claims

1. A treatment method after plating with Sn or an Sn alloy, comprising: Immediately after the plating, at least one of the members used in the series of plating treatments is washed with an acidic solution containing an acid and / or a salt thereof and having a pH of 5 or less; the acidic solution contains at least one complexing agent selected from the group consisting of gluconic acid, glycine, glucoheptonic acid, gluconolactone, glucoheptolactone, sorbic acid, and salts thereof; The treatment method, wherein the content of the acid and / or its salt in the acidic solution is 100 g / L to 700 g / L.

2. The method according to claim 1 , wherein the plating with Sn or an Sn alloy is electroplating with Sn or an Sn alloy.

3. The processing method according to claim 1 or 2, wherein the member is a substrate and a transport jig therefor.

4. The processing method according to claim 3 , wherein the cleaning with the acidic solution is performed while the substrate remains fixed to the transport jig.

5. 5. The method according to claim 1, wherein the acid and / or salt thereof is one or more organic acids and / or salts thereof.

6. The treatment method according to any one of claims 1 to 5, wherein the acidic solution contains one or more chelating agents.

7. 7. The treatment method according to claim 1, wherein the acidic solution contains one or more nonionic surfactants or ionic surfactants.

8. At least one of the members is at least a substrate transport jig; After repeating the plating with the Sn or Sn alloy and the washing with the acidic solution 30 times, the coverage of the surface of the conveying jig with Sn or Sn alloy compound stains is 0% to 30%; The degree of coverage is The surface of the transport jig after the plating and cleaning are repeated is observed with a field emission scanning electron microscope; The observation area of ​​the surface of the conveying jig is divided into 4 × 5 squares, The following formula (1): Coverage (%) = (number of squares with dirt particles attached / total number of squares) × 100 (1) The processing method according to claim 1 or 2, wherein the calculation is based on the following formula:

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