JP5377058B2 - Detergent composition for hard disk substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detergent composition for a substrate for an HD (hard disk), which is suitably used for a substrate to be cleaned, obtained by polishing a substrate to be polished with a polishing liquid composition containing silica fine particles, and rinsing the polished substrate with water, which is excellent in a cleaning property and foaming resistance, and which obtains a highly cleaned substrate for an HD even by short-time cleaning, and to provide a method for producing the substrate for an HD with high cleanness using the composition. <P>SOLUTION: The detergent composition for the substrate for an HD has an Ni-P containing layer, and includes: a specification acrylic acid-based copolymerization compound and/or its salt (component (A)); polyamine (component (B)); and water (component C), however substantially does not include nonionic surfactant, wherein the content of the component (B) with respect to the total weight of the components excluding the component (C) is 30-95 wt.%, and a weight ratio of the component (A) to the component (B):äcomponent (A)/component (B)} is 0.04-0.8. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a cleaning composition for a hard disk substrate and a method for manufacturing a hard disk substrate using the cleaning composition for a hard disk substrate.

  In the process of manufacturing an HD (hard disk) substrate, a polishing composition containing inorganic fine particles such as silica fine particles as an abrasive (polishing fine particles) is usually used in the final polishing performed on the substrate to be polished. In addition, in the manufacturing process of the HD substrate, there is a step of rinsing the polished substrate with water in order to increase the cleaning efficiency after polishing the substrate to be polished. The contact with water causes inorganic fine particles remaining on the substrate after polishing, particularly silica fine particles, to aggregate, making it difficult to remove the inorganic fine particles in the subsequent cleaning step.

  In Patent Document 1, inorganic fine particles agglomerate when a polished substrate is washed with pure water in the process of manufacturing a semiconductor substrate. A cleaning method for cleaning with an agent is disclosed.

  In Patent Document 2, the ratio (molar ratio) between the structural unit derived from acrylic acid and the structural unit derived from 2-acrylamido-2-methylpropanesulfonic acid is 91/9 to 95/5. Disclosed is a detergent composition comprising a copolymer compound or a salt thereof in which the total proportion of the structural unit derived from 2-acrylamido-2-methylpropanesulfonic acid in all the structural units is 90 mol% or more. Has been. Patent Document 2 describes that, from the viewpoint of more effectively removing fine particles, the cleaning composition is preferably alkaline, and preferably contains an alkaline agent such as amino alcohol.

Patent Document 3 discloses an alkaline aqueous solution composition used for cleaning or etching a silicon wafer, which contains a specific chelating agent having an aromatic ring such as N, N-bis (salicylidene) 1,2-ethanediamine and an alkali component. Things are disclosed.
JP 11-191544 A JP 2007-291328 A JP 2008-305900 A

  Due to the rapid increase in density of HD, the degree of cleanliness required for the HD substrate is high, and even a small amount of inorganic fine particles is a cause of lowering the quality and yield of the HD substrate. Moreover, in order to raise production efficiency, it exists in the tendency to shorten washing | cleaning time, and the further outstanding cleaning property is calculated | required by the cleaning composition. In a substrate used for a higher density hard disk, when the substrate after polishing immediately after polishing is rinsed with water and then cleaned with the cleaning composition, the conventional cleaning composition is sufficient. In some cases, detergency was not obtained.

  Further, there is a demand for a cleaning composition that not only exhibits excellent detergency but also has little contamination to the cleaning equipment, that is, less foaming (that is, exhibits excellent foaming resistance). However, there has not yet been obtained a cleaning composition that has excellent cleaning properties and antifoaming properties, and can obtain a highly purified HD substrate even after a short cleaning.

  The present invention is suitably used for a substrate to be cleaned obtained by polishing a substrate to be cleaned with a polishing composition containing silica fine particles and then rinsing with water, and has excellent cleaning properties and foam resistance. The present invention provides a cleaning composition for an HD substrate that provides a highly purified substrate even after a short period of cleaning, and a method for manufacturing an HD substrate with high cleanliness using the same.

The cleaning composition for the HD substrate of the present invention comprises:
The ratio (molar ratio) between the structural unit derived from acrylic acid and the structural unit derived from 2-acrylamido-2-methylpropanesulfonic acid is 91/9 to 95/5, and the structural unit derived from acrylic acid and 2 A copolymer compound and / or a salt thereof (component (A)) in which the total proportion of the structural units derived from acrylamido-2-methylpropanesulfonic acid is 90 mol% or more;
A polyamine (component (B));
Water (component (C)),
Substantially free of nonionic surfactants,
Content of the said component (B) in the sum total of the weight of components other than the said component (C) is 30 to 95 weight%,
The weight ratio {component (A) / component (B)} of the component (A) and the component (B) is 0.04 to 0.8.
It is a cleaning composition for a hard disk substrate having a Ni-P-containing layer.

  The method for producing a substrate for HD of the present invention comprises a step of polishing a substrate to be cleaned with a polishing composition containing silica fine particles and then rinsing with water to obtain the substrate to be cleaned. And a step of washing with the detergent composition.

  According to the present invention, the substrate to be polished is suitably used for a substrate to be cleaned obtained by polishing with a polishing composition containing silica fine particles and then rinsing with water, and has excellent cleaning properties and antifoaming properties. It is possible to provide a cleaning composition for an HD substrate and a method for producing an HD substrate using the same, which can exhibit a highly purified substrate even after cleaning for a short time.

  The inventors include a specific copolymer compound and / or a salt thereof (component (A)), a polyamine (component (B)), and water (component (C)), and a polyamine (component (B). )) Content is set to a predetermined amount and the weight ratio {component (A) / component (B)} is set to a predetermined value so that substantially no nonionic surfactant is contained. The present inventors have found that dirt on the surface of the substrate to be cleaned can be effectively removed. Although the mechanism is not clear, the applicant presumes that it is as follows. However, the present invention is not limited to this mechanism.

  The cleaning composition for HD substrates of the present invention (hereinafter sometimes abbreviated as “the cleaning composition of the present invention”) contains a predetermined amount of polyamine (component (B)). Therefore, Ni contained in the surface of the substrate to be cleaned can be positively corroded (etched), and the dirt (mainly in the polishing scraps and the abrasive composition) adhered to the surface of the substrate to be cleaned with the etching. Including silica fine particles, etc.) can be lifted from the substrate to be cleaned. In the cleaning composition of the present invention, since the polyamine (component (B)) forms a complex with Ni ions described later, Ni ions attached to the surface of the substrate to be cleaned may precipitate as nickel hydroxide. Can be suppressed.

  Since the polishing of the substrate to be polished including the Ni-P layer is performed under an acidic condition, Ni is eluted from the substrate to be polished. When the substrate to be polished after polishing is cleaned using an alkaline cleaning composition, Ni ions attached to the substrate to be polished after polishing are precipitated as nickel hydroxide. In addition, Ni-P polishing waste is oxidized and remains as nickel oxide on the polished substrate. This nickel oxide and nickel hydroxide are considered to hinder the improvement of yield for HD substrates and the reduction of production time.

  The cleaning composition of the present invention has a specific copolymer compound and / or a salt thereof (component (A)) and a polyamine (component (B)) in a weight ratio {component (A) / component (B)}. Since a specific copolymer compound and / or a salt thereof (component (A)) is contained so as to be 0.04 to 0.8, the above-mentioned dirt that floats from the substrate to be cleaned or remains on the substrate to be cleaned The nickel oxide thus obtained can be dispersed in the cleaning composition of the present invention by a specific copolymer compound and / or a salt thereof (component (A)). Therefore, it is possible to suppress aggregation of inorganic fine particles, particularly silica fine particles, contained in the dirt and the like, and it is possible to prevent reattachment of the raised dirt and the like to the surface of the substrate to be cleaned.

  Therefore, the cleaning composition of the present invention is positively etched by polyamine (component (B)), trapped by Ni ions, and lifted by the specific copolymer compound and / or salt thereof (component (A)). High detergency is exhibited even in a short period of time due to dispersion of dirt and the like and prevention of redeposition.

  In precision cleaning, a nonionic surfactant that is considered to be suitable for removing oil stains is often used as one component of the cleaning composition. However, in the manufacturing process of the HD substrate, dirt mainly adhering to the substrate to be cleaned is inorganic dirt containing silica fine particles, and there are not many oil stains adhering to the substrate to be cleaned.

  As described above, in the cleaning using the cleaning composition of the present invention, a relatively large amount of Ni contained in the surface of the substrate to be cleaned is etched by the polyamine (component (B)). Even if it does not contain substantially, dirt other than silica fine particles (including organic dirt such as oil dirt) can be removed. Rather, the cleaning composition of the present invention exhibits excellent foaming resistance by substantially not containing a nonionic surfactant, and thus has good rinsing properties. Therefore, if the cleaning composition of the present invention is used, the cleaning time can be shortened, and the cleaning composition of the present invention contributes to the improvement of the productivity of HD substrates.

  As described above, since the cleaning composition of the present invention exhibits excellent cleaning properties and foaming resistance, if an HD substrate is produced using the cleaning composition of the present invention, contamination of cleaning equipment and the like can be prevented. It is possible to manufacture an HD substrate with a high cleanliness while enabling reduction and improvement in productivity. Note that cleaning of electronic parts having metal wiring or the like is usually performed without causing metal corrosion in order to disconnect the wiring.

  The cleaning composition of the present invention comprises at least a specific copolymer compound and / or a salt thereof (component (A)), a polyamine (component (B)), and water (component (C)). It is the cleaning composition which becomes.

  The cleaning composition of the present invention does not substantially contain a nonionic surfactant, but from the viewpoint of improving the cleaning property by further improving the rinsing property and improving the anti-foaming property. More preferably, no ionic surfactant is contained. “Substantially free of nonionic surfactant” means that the content of nonionic surfactant is 0.01% by weight or less, but the content of nonionic surfactant Is preferably 0.005% by weight or less, more preferably 0.001% by weight or less, and still more preferably 0% by weight.

  Next, each component contained in the cleaning composition of the present invention will be described in detail.

<Component (A): Specific copolymer compound and / or salt thereof>
The specific copolymer compound and / or salt thereof (component (A)) contained in the cleaning composition of the present invention is composed of a structural unit derived from acrylic acid and a structure derived from 2-acrylamido-2-methylpropanesulfonic acid. The ratio (molar ratio) to the unit is 91/9 to 95/5, and the ratio of the structural unit derived from acrylic acid and the structural unit derived from 2-acrylamido-2-methylpropanesulfonic acid in all the structural units Is a copolymer compound and / or a salt thereof having a total of 90 mol% or more. Component (A) serves to disperse dirt and the like that has been lifted by etching in the cleaning composition of the present invention and to suppress aggregation of inorganic fine particles including silica fine particles contained in the dirt and the like it is conceivable that.

  In the component (A), the ratio (molar ratio) between the structural unit derived from acrylic acid and the structural unit derived from 2-acrylamido-2-methylpropanesulfonic acid is a component that prevents aggregation of inorganic fine particles including silica fine particles ( A / 9 to 95/5 from the viewpoint of achieving both the prevention of reduction of the removability of the inorganic fine particles due to the decrease in water solubility of A), but from the same viewpoint, it is preferably 91/9 to 93/7. .

  In the component (A), the total of the proportion of the structural unit derived from acrylic acid and the structural unit derived from 2-acrylamido-2-methylpropanesulfonic acid in all the structural units is 90 mol% from the viewpoint of improving detergency. From the same viewpoint, it is preferably 95 mol% or more, and more preferably substantially 100 mol%.

  In the case where the component (A) is a copolymer compound salt, specifically, alkali metal salts such as sodium salt and potassium salt, or a molecular weight of 300 or less from the viewpoint of preventing aggregation of inorganic fine particles and improving detergency. Of these, salts with nitrogen-containing compounds are preferred. Examples of the nitrogen-containing compound having a molecular weight of 300 or less include monoethanolamine, diethanolamine, triethanolamine, methylethanolamine, monopropanolamine obtained by adding ethylene oxide, propylene oxide, etc. to ammonia, alkylamine or polyalkylpolyamine, Examples include amino alcohols such as dipropanolamine, tripropanolamine, methylpropanolamine, monobutanolamine, and aminoethylethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide and choline. Among these, alkali metal salts are preferable, sodium salts and potassium salts are more preferable, and sodium salts are even more preferable from the viewpoint of preventing aggregation of inorganic fine particles and improving detergency.

  The weight average molecular weight of the copolymer of component (A) achieves both prevention of aggregation of inorganic fine particles including silica fine particles and prevention of decrease in removability of inorganic fine particles including silica fine particles due to a decrease in water solubility of component (A). In view of the above, it is preferably 1,000 to 100,000, more preferably 1,000 to 50,000, and still more preferably 5,000 to 30,000. The weight average molecular weight of a component (A) can be calculated | required by the following gel permeation chromatography (GPC).

(GPC conditions)
Column: G4000PWXL + G2500PWXL (manufactured by Tosoh Corporation)
Eluent: 0.2M phosphate buffer / CH ₃ CN = 9/1 (volume ratio)
Flow rate: 1.0 mL / min
Column temperature: 40 ° C
Detection: RI
Sample size: 0.2 mg / mL
Standard substance: Polyethylene glycol (weight average molecular weight: 194,400,600,1000,1500,4000,7000,10000,13000,20000; manufactured by GL Sciences Inc.)

  Component (A) is prepared by, for example, copolymerizing acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid in an aqueous medium in the presence of a polymerization initiator and a chain transfer agent by a known polymerization method. If necessary, the polymer obtained can be obtained by neutralizing with an alkali.

As polymerization initiators, 2,2′-azobisisobutylnitrile, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] disulfate dihydrate, ammonium persulfate, hydrogen peroxide , Sodium persulfate, NaHSO ₃ or the like, and examples of the chain transfer agent include isopropyl alcohol, NaHSO ₃ or the like.

  The weight average molecular weight of the component (A) is generally controlled by the input amount of the chain transfer agent. The more chain transfer agent, the smaller the weight average molecular weight, and the less chain transfer agent, the larger the weight average molecular weight.

  The component (A) is preferably a salt of the specific copolymer compound from the viewpoint of preventing aggregation of inorganic fine particles including silica fine particles and improving detergency. As an example of a commercial product of an aqueous solution of a sodium salt of the specific copolymer compound, (acrylic acid / 2-acrylamido-2-methylpropanesulfonic acid copolymer compound (92/8 (molar ratio), weight average molecular weight 12,000) ) And 40% by weight aqueous solution of sodium salt).

  Including the component (A) contained in the cleaning composition of the present invention in the total weight of components other than the component (C) from the viewpoint of improving the cleaning properties by preventing aggregation of inorganic fine particles including silica fine particles The amount is preferably 5 to 50% by weight, more preferably 15 to 25% by weight, and still more preferably 15 to 18% by weight.

  In the present invention, the “component other than the water (component (C))” may be composed of only the component (A) and the component (B), and as an optional component, a chelating agent (component (D)), It may further contain at least one selected from the group consisting of alkali metal hydroxides (component (E)), alcohol, preservatives, and antioxidants. In that case, the cleaning composition of the present invention is at least selected from the group consisting of chelating agents (component (D)), alkali metal hydroxides (component (E)), alcohols, preservatives, and antioxidants. 1 type, a component (A), a component (B), and a component (C) are mix | blended.

<Component (B): Polyamine>
The polyamine contained in the cleaning composition of the present invention is an aliphatic compound having two or more amino groups or imino groups. The polyamine etches the surface of the substrate to be cleaned to lift the dirt adhering to the surface of the substrate to be cleaned from the substrate to be cleaned, and Ni ions adhering to the surface of the substrate to be cleaned are precipitated as nickel hydroxide. It is thought that it works to suppress doing. Polyamines include ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, neopentanediamine, 3-methylaminopropylamine, diethylenetriamine, dipropylenetriamine, triethylenetetramine, N- (β-aminoethyl) ethanol An amine, aminoethylisopropanolamine and the like can be mentioned. From the viewpoint of improving the detergency, N- (β-aminoethyl) ethanolamine, diethylenetriamine, and triethylenetetramine are preferable, and diethylenetriamine, N- (β-amino is more preferable. Ethyl) ethanolamine, more preferably N- (β-aminoethyl) ethanolamine.

  From the viewpoint of improving the cleaning performance by improving the etching performance and effectively suppressing the precipitation of nickel hydroxide, the weight of components other than the water (component (C)) contained in the cleaning composition of the present invention. The content of the component (B) in the total is 30 to 95% by weight, but from the same viewpoint, it is preferably 35 to 65% by weight, more preferably 38 to 43% by weight.

  For example, when “the component other than the water (component (C))” is composed of the component (A) and the component (B), the total weight of the component (A) and the component (B) Although content is 30 to 95 weight%, Preferably it is 35 to 65 weight%, More preferably, it is 38 to 43 weight%. For example, when “the component other than the water (component (C))” is composed of at least one of the component (D) and the component (E), the component (A), and the component (B), The content of component (B) in the sum of the weights of (D) and at least one of component (E), component (A) and component (B) is 30 to 95% by weight, preferably 35 It is -65 weight%, More preferably, it is 38-43 weight%. For example, when “the component other than the water (component (C))” is composed of the component (D), the component (E), the component (A), and the component (B), the component (D) The content of the component (B) in the sum of the weights of the component (E), the component (A) and the component (B) is 30 to 95% by weight, preferably 35 to 65% by weight, more preferably Is 38 to 43% by weight. For example, “the component other than the water (component (C))” is at least one selected from the group consisting of alcohol, preservatives and antioxidants, component (A), component (B), and component ( D) and component (E), at least one selected from the group consisting of alcohol, preservatives and antioxidants, component (A), component (B), component (D), The content of the component (B) in the total weight of the component (E) is 30 to 95% by weight, preferably 35 to 65% by weight, and more preferably 38 to 43% by weight.

  In the cleaning composition of the present invention, the weight ratio {component (A) / component (B)} of component (A) to component (B) improves etching performance and effectively suppresses precipitation of nickel hydroxide. From the viewpoint of improving the washability, it is 0.04 to 0.8, but from the same viewpoint, it is preferably 0.08 to 0.7, more preferably 0.08 to 0.5. is there.

<Ingredient (C): Water>
The water contained in the cleaning composition of the present invention is not particularly limited as long as it can serve as a solvent. For example, ultrapure water, pure water, ion exchange water, or distilled water can be used, but ultrapure water, pure water, or ion exchange water is preferable, and ultrapure water is more preferable. Pure water and ultrapure water can be obtained, for example, by passing tap water through activated carbon, subjecting it to ion exchange treatment, and further distilling it, irradiating it with a predetermined ultraviolet germicidal lamp as necessary, or passing it through a filter. Can do. In the present invention, the electrical conductivity at 25 ° C. is 1 μS / cm or less for pure water and 0.1 μS / cm or less for ultrapure water.

  Embodiments of the cleaning composition of the present invention include Embodiment 1 in which the water content is 50 wt% or more and 98 wt% or less, and Embodiment 2 in which the water content exceeds 98 wt%. In aspect 1, since content (content rate) of the water in a cleaning composition is comparatively small, it is suitable as an aspect at the time of conveyance and storage. The cleaning composition of Embodiment 2 is obtained, for example, by diluting the cleaning composition of Embodiment 1, and the content of water (component (C)) is 98% by weight without passing through the state of Embodiment 1. It can be obtained by mixing water (component (C)) and the remaining components so as to exceed, and can also be obtained by mixing aqueous solutions containing each component of the cleaning composition.

<Optional component>
In addition to components (A), (B), and (C), the cleaning composition of the present invention includes a chelating agent (component (D)), an alkali metal hydroxide (component (E)), alcohol, and a preservative. Further, an antioxidant or the like may be contained. For example, the alcohol includes ethanol, propanol and the like, and the antiseptic includes 1,2-benzisothiazolin-3-one, 2-methyl-4-isothiazolin-3-one and the like, and the antioxidant. Ascorbic acid, benzotriazole, etc. are mentioned.

(Component (D): Chelating agent)
The cleaning composition of the present invention contains a chelating agent (component (D)) from the viewpoint of further improving the cleaning performance by capturing Ni ions and further suppressing the precipitation of Ni on the substrate to be cleaned. It is preferable. Chelating agents (component (D)) include aldonic acids such as gluconic acid and glucoheptonic acid; aminocarboxylic acids such as ethylenediaminetetraacetic acid; hydroxycarboxylic acids such as citric acid and malic acid; aminotrimethylenephosphonic acid, 1-hydroxy And phosphonic acids such as ethylidene-1,1-diphosphonic acid; and at least one selected from the group consisting of alkali metal salts, lower amine salts, ammonium salts and alkanol ammonium salts. Among these, sodium gluconate, sodium glucoheptonate, sodium ethylenediaminetetraacetate, sodium citrate, or 1-hydroxyethylidene-1,1-diphosphonic acid from the viewpoint of effectively suppressing the precipitation of Ni on the substrate to be cleaned Phosphonic acids such as 1-hydroxyethylidene-1,1-diphosphonic acid are more preferable. These chelating agents may be used alone or in admixture of two or more.

  Chelating agent (component (D)) in the total weight of components other than component (C) from the viewpoint of further improving the cleanability by capturing Ni ions and suppressing the precipitation of Ni on the substrate to be cleaned. The content of is preferably 5 to 40% by weight, more preferably 8 to 25% by weight, and still more preferably 8 to 13% by weight.

  The weight ratio of {polyamine (component (B)) to chelating agent (component (D)) {component (B) / component (D)} From the viewpoint of improving the detergency and further improving the detergency by suppressing the precipitation of Ni, it is preferably 1 to 10, more preferably 2 to 5, and further preferably 3 to 5. is there.

(Component (E): Alkali metal hydroxide)
The cleaning composition of the present invention contains an alkali metal hydroxide (component (E)) from the viewpoint of further improving cleaning properties by dissolving silica fine particles adhering to the surface of the substrate to be cleaned. And preferred. As the alkali metal hydroxide, sodium hydroxide, potassium hydroxide, and the like are preferable from the viewpoint of improving detergency, but potassium hydroxide is more preferable from the viewpoint of ensuring long-term storage stability of the detergent composition.

(PH of cleaning composition)
The cleaning composition of the present invention preferably has a pH of 9 to 14 at 25 ° C., more preferably, from the viewpoint of further improving the cleaning properties by dissolving silica fine particles adhering to the surface of the substrate to be cleaned. 11-14, and more preferably 12-14. For adjusting the pH to a value within the above range, it is preferable to use an alkali metal hydroxide (component (E)). In addition, pH can be measured using a pH meter (manufactured by Toa Denpa Kogyo Co., Ltd., HM-30G).

  The content of alkali metal hydroxide in the total weight of the components other than the component (C) from the viewpoint of achieving both the improvement of the detergency by dissolution of the silica fine particles and the securing of long-term storage stability of the detergent composition Is preferably 5 to 40% by weight, more preferably 10 to 37% by weight, and still more preferably 20 to 34% by weight.

  The weight ratio {component (E) / component (B)} between the alkali metal hydroxide (component (E)) and the polyamine (component (B)) improves the etching performance and precipitates nickel hydroxide. From the viewpoint of further improving the detergency by more effectively suppressing, and from the viewpoint of achieving both the improvement of the detergency by dissolution of the silica fine particles and ensuring the long-term storage stability of the detergent composition, It is 0.1-3, More preferably, it is 0.2-0.9, More preferably, it is 0.5-0.8.

  The cleaning composition of the present invention preferably contains the component (D) and the component (E) from the viewpoint of further improving the cleaning properties by dissolving the silica fine particles and capturing Ni ions.

(Method for preparing cleaning composition)
The method for preparing the cleaning composition of the present invention is not limited at all. For example, component (A), component (B), and optional components as necessary are added to water (component (C)) and mixed. The method of doing is mentioned. There is no particular limitation on the order of adding each component to water (component (C)). The mixing method may be a known method, but it is preferable that each component is added to the water being stirred. The temperature of water when each component is added to water is preferably 20 to 50 ° C. The rotational speed of the stirring motor is usually preferably a peripheral speed of 0.1 m / s to 0.65 m / s. The stirring time after adding all the components other than water to water is usually preferably 0.5 to 2 hours.

(Manufacturing method of HD substrate)
In the method for producing an HD substrate according to the present invention, a substrate to be cleaned is obtained by polishing the substrate to be cleaned with a polishing composition containing an abrasive containing silica fine particles (polishing fine particles) and then rinsing with water. And a step of cleaning the substrate to be cleaned with the cleaning composition of the present invention after this step.

  Examples of the HD substrate include a circular substrate in which a Ni-P layer is formed on a metal substrate such as an aluminum substrate. HD is obtained by forming a magnetic layer on these HD substrates by a method such as sputtering. Examples of the metal material constituting the magnetic layer include chromium, tantalum, or a cobalt alloy that is an alloy of platinum and the like and cobalt.

  In the manufacturing process of the HD substrate, in order to improve the surface smoothness of at least one main surface of the HD substrate, for example, an abrasive made of inorganic fine particles including silica fine particles and a dispersion solvent of the abrasive (for example, And a polishing step of polishing at least one main surface of the substrate to be polished using a polishing composition containing water. On the polished surface of the substrate to be polished (polished substrate) that has undergone this polishing step, dirt (inorganic fine particles such as silica fine particles, organic matter, etc.) derived from the polishing liquid composition, metal ions derived from equipment such as equipment and polishing pads, Organic matter is attached. Since the cleaning composition of the present invention exhibits excellent detergency against these stains, the HD substrate having a high cleanliness can be manufactured according to the HD substrate manufacturing method of the present invention.

  For polishing the substrate to be polished, for example, the polishing composition is supplied between the object to be polished and the polishing pad, and the substrate to be polished and the polishing pad are in contact with each other with a predetermined pressure ( The load is applied by moving the polishing pad relative to the substrate to be polished. In addition, the said grinding | polishing can be performed with a conventionally well-known grinding | polishing apparatus.

  The polishing composition may be used as it is, or diluted if it is a concentrated solution. When diluting the concentrate, the dilution ratio is not particularly limited, and can be appropriately determined according to the concentration of each component (such as the content of the abrasive) in the concentrate, the polishing conditions, and the like.

  The polishing pad is not particularly limited, and a conventionally known polishing pad can be used. Examples of the material for the polishing pad include organic polymers, and examples of the organic polymer include polyurethane. The shape of the polishing pad is preferably a nonwoven fabric.

  The polishing load means the pressure of the surface plate applied to the polishing surface of the substrate to be polished during polishing. The polishing load in the production method of the present invention is preferably 3 to 50 kPa, more preferably 5 to 40 kPa, and even more preferably 7 to 30 kPa in order to improve productivity while effectively suppressing roll-off. The polishing load can be adjusted by the load of air pressure or weight on the surface plate or the substrate to be polished.

The supply rate of the polishing composition is preferably 0.01 to 0.25 mL / min per 1 cm ^{2 of the} substrate to be polished, more preferably 0.025 to 0. 0, from the viewpoint of achieving both cost reduction and improvement of the polishing rate. It is 2 mL / min, More preferably, it is 0.05-0.15 mL / min.

  The rinsing method using water for the substrate after polishing is, for example, a method of supplying water instead of the polishing composition using a polishing apparatus, a method of contacting in a water bath of an ultrasonic cleaning apparatus, and spraying water. Examples include a method of injecting and contacting (shower method), among others, from the viewpoint of preventing excessive etching of the post-polishing substrate caused by contact between the polishing composition having a low pH and the post-polishing substrate for a long time. A method of supplying water instead of the polishing composition using a polishing apparatus is preferred.

  The water used for rinsing is preferably at least one kind of ultrapure water or pure water because unnecessary impurities do not adhere to the substrate after polishing.

  When the rinsing method using water is, for example, a method of supplying water instead of the polishing composition using a polishing apparatus, a predetermined pressure (load) is applied to the substrate after polishing with the polishing pad, and Supplying water while moving the polishing pad relative to the post-polishing substrate is preferable because the excess polishing composition can be efficiently removed.

The amount of water used for rinsing is preferably 20 to 80 mL per unit area of the substrate after polishing, because it removes as much acid as possible from the polishing composition and suppresses excessive corrosion of the substrate after polishing. / Cm ² , more preferably 25-80 mL / cm ² , still more preferably 30-80 mL / cm ² .

  In the step of cleaning the substrate to be cleaned obtained by rinsing with water after polishing with the polishing liquid composition, for example, (a) the substrate to be cleaned (cleaning target) is cleaned with the cleaning agent. It is immersed in the composition and / or (b) the cleaning composition is injected to supply the cleaning composition onto the surface of the substrate to be cleaned.

  In the method (a), the conditions for immersing the substrate to be cleaned in the cleaning agent composition are not particularly limited. For example, the temperature of the cleaning agent composition is determined from the viewpoint of ensuring high safety and the cleaning time. From the viewpoint of shortening, the temperature is preferably 20 to 100 ° C., and the immersion time is preferably 10 seconds to 30 minutes from the viewpoint of ensuring high detergency and shortening the cleaning time. In addition, from the viewpoint of enhancing the removability of inorganic fine particles containing silica fine particles and the dispersibility of inorganic fine particles containing silica fine particles, it is preferable that ultrasonic vibration is imparted to the cleaning composition. The frequency of the ultrasonic wave is preferably 20 to 2000 kHz, more preferably 100 to 2000 kHz, and further preferably 1000 to 2000 kHz.

  In the method (b), from the viewpoint of promoting the cleaning property of inorganic fine particles including silica fine particles and the solubility of oil components, the cleaning composition to which ultrasonic vibration is applied is injected to clean the surface to be cleaned. It is preferable that the cleaning composition is brought into contact with the surface to be cleaned, or the cleaning composition is supplied by injection onto the surface to be cleaned, and the surface to which the cleaning composition is supplied is cleaned by rubbing with a cleaning brush. . Furthermore, it is preferable to clean the surface by supplying a cleaning composition to which ultrasonic vibration is applied to the surface by injection and rubbing the surface to which the cleaning composition is supplied with a cleaning brush.

  As means for supplying the cleaning composition to the surface to be cleaned, known means such as a spray nozzle can be used. Moreover, there is no restriction | limiting in particular as a brush for washing | cleaning, For example, well-known things, such as a nylon brush and a PVA sponge brush, can be used. The frequency of the ultrasonic wave may be the same as that used in the method (a).

  In addition to the method (a) and / or the method (b), the cleaning is performed by at least one of known cleaning methods such as rocking cleaning, cleaning using rotation of a spinner, and paddle cleaning. You may carry out by the method.

  In the cleaning process of the substrate to be cleaned, the substrates to be cleaned that are to be cleaned may be cleaned one by one, or a plurality of substrates to be cleaned may be cleaned at a time. The number of cleaning tanks used for cleaning may be one or more.

  By blending and mixing the components so as to have the compositions described in Table 1 and Table 2, the cleaning compositions of Examples 1 to 8 and Comparative Examples 1 to 11 (cleaning compositions of Embodiment 1) were obtained. It was.

  The following tests (1) to (6) were performed using the obtained cleaning composition. In addition, the pH of the diluted solution (cleaning composition of aspect 2) obtained by diluting each cleaning composition (cleaning composition of aspect 1) 100 times with water is a pH meter (manufactured by Toa Denpa Kogyo Co., Ltd., HM-30G) and the results are shown in Tables 1 and 2.

(1) Zeta potential measurement test 1 g of nickel oxide powder (manufactured by Sigma-Aldrich, Nanopowder, purity 99.8%) was added to 100 g of water to prepare a nickel oxide dispersion. Next, the nickel oxide dispersion prepared in advance in 50 g of a diluted solution (cleaning composition of aspect 2) obtained by diluting each of the cleaning compositions (cleaning composition of aspect 1) 100 times with water. The liquid 0.1g was added, and it left still for 24 hours, and was set as the measurement sample. 15 ml of the measurement sample was injected into a zeta potential measurement device (manufactured by Nippon Luft, model number: Model 502), and measurement was performed at a voltage of 50 mV. The zeta potential was measured three times, the average value was evaluated according to the evaluation criteria described later, and the results are shown in Tables 1 and 2.

In addition, when the to-be-polished substrate which has a Ni-P layer is grind | polished, the grinding | polishing waste containing Ni-P will come out, but Ni-P contained in this grinding | polishing waste is an oxidizing agent in a polishing liquid composition by natural oxidation. Is oxidized to nickel oxide. When the zeta potential is high, the repulsion between nickel oxides becomes strong. That is, the higher the zeta potential, the higher the dispersibility of the nickel oxide particles, and this test allows the evaluation of the dispersibility of the nickel oxide particles in the cleaning composition.
(Evaluation criteria for zeta potential)
A: 60 mV or more B: 40 mV or more and less than 60 mV C: less than 40 mV

(2) Etching amount measurement test Ni etching amount by the diluted solution (cleaning agent composition of embodiment 2) obtained by diluting each of the cleaning compositions (cleaning agent composition of embodiment 1) with water 100 times will be described later. Evaluation based on the evaluation criteria. The results are shown in Tables 1 and 2.
(A) Put 70 g of each diluent in a 2 L polyethylene container (bottom diameter 125 mm × height 185 mm), and use the diluted solution stored in a thermostatic bath at 25 ° C. for 3 hours as a test solution.
(B) A substrate (outer diameter: 95 mmφ, inner diameter: 25 mmφ, thickness: 1.27 mm) made of a Ni—P plated aluminum alloy is immersed in the test solution for 10 minutes.
(C) After the substrate is taken out from the test solution, the Ni etching amount is measured for the test solution by measuring the emission intensity of nickel with an ICP emission spectrometer (Optima 5300, manufactured by Perkin Elmer).

(Evaluation criteria for Ni etching amount)
A: 2.5 ppm or more B: 1.5 ppm or more and less than 2.5 ppm C: 0.6 ppm or more and less than 1.5 ppm D: less than 0.6 ppm

(3) Solubility test of nickel sulfate To 19.95 g of the diluted solution (cleaning composition of aspect 2) obtained by diluting each of the cleaning compositions (cleaning composition of aspect 1) 100 times with water , 0.05 g of nickel sulfate hexahydrate (manufactured by Sigma-Aldrich, reagent special grade) was added. After 24 hours, the supernatant of the diluted solution to which nickel sulfate hexahydrate was added was filtered through a filter (manufactured by Advantech, DISMIC-25HP020AN, pore size 0.2 μm), and the supernatant was used as a test solution. About the said test liquid, the light emission intensity | strength of nickel was measured using the ICP emission spectrometer (The Perkin-Elmer company make, Optima5300), and Ni density | concentration in a test liquid was quantified. It shows that the solubility of nickel sulfate with respect to a dilution liquid is so high that Ni ion concentration is high. The level of Ni concentration in the test solution is a measure of whether or not Ni ions generated during substrate polishing are suppressed from being precipitated as nickel hydroxide in the alkaline cleaning composition. If the Ni concentration is high, nickel hydroxide is difficult to precipitate, and if the Ni concentration is low, nickel hydroxide is likely to precipitate.
(Standard for solubility evaluation of nickel sulfate)
A: 700 ppm or more B: 500 ppm or more and less than 700 ppm C: less than 500 ppm

(4) Silica Solubility Test In a 100 ml plastic container, 20 g of a diluent obtained by diluting the cleaning composition (cleaning composition of aspect 1) 100 times with water (cleaning composition of aspect 2) In addition, 0.1 g of silica powder (Aerosil 50, manufactured by Nippon Aerosil Co., Ltd.) was added. Next, these were stirred for 15 minutes with a magnetic stirrer (rotor: 40 mm, outer peripheral speed: 1.5 m / s), and the supernatant liquid was filtered with a filter (manufactured by Advantech, DISMIC-25HP020AN, pore size 0.2 μm). The supernatant was used as a test solution. For the test solution, the Si emission intensity was measured using an ICP emission analyzer (manufactured by Perkin Elmer, Optima 5300), and the Si concentration in the test solution was quantified. The higher the Si concentration in the test solution, the higher the ability of the diluted solution to remove silica fine particles (abrasive) attached to the surface of the substrate to be cleaned by dissolution.
(Evaluation criteria for silica solubility)
A: 50 ppm or more B: 20 ppm or more and less than 50 ppm C: less than 20 ppm

(5) Foaming resistance test 60 ml of a diluted solution (cleaning composition of embodiment 2) obtained by diluting each of the cleaning compositions (cleaning composition of embodiment 1) 100 times with water in a 200 ml cylinder Put in the lid. Next, the cylinder was vigorously vibrated by 20 reciprocating hand shakes, and the foam height (height from the liquid surface to the highest part of the foam) after being allowed to stand for 30 seconds was measured. Sex was evaluated. The lower the foam height, the better the foam resistance. When the cylinder was vibrated strongly, the stroke length was 30 cm and the hand shaking speed was 2 times / second.

(Evaluation criteria for foaming resistance)
A: Bubble height is less than 20 ml B: Bubble height is 20 ml or more

(6) Detergency test Preparation of substrate to be cleaned of Ni-P plated aluminum alloy (outer diameter: 95 mmφ, inner diameter: 25 mmφ, thickness: 1.27 mm, surface roughness (arithmetic mean roughness, Ra): 1 nm, 10 sheets) Both main surfaces were polished by a double-sided processing machine while supplying a polishing composition described later. The polishing conditions were as described below. Subsequently, pure water was supplied in place of the polishing composition, and the substrate after polishing was rinsed with pure water under the conditions described later to obtain a substrate to be cleaned (cleaning target).

2. Polishing condition polishing machine: double-sided 9B polishing machine (manufactured by Speed Fam)
Polishing pad: Suede type (Thickness: 0.9mm, average hole diameter: 30μm, manufactured by Fujibow)
Polishing liquid composition: Colloidal silica slurry (Product number: Memorized 2P-2000, manufactured by Kao Corporation)
Main polishing: Load 100g / cm ² , time 300 seconds, polishing composition flow rate 100mL / min

3. Rinsing conditions Electrical conductivity of pure water: 0.71 μS / cm
Load: 30 g / cm ²
Time: 20 seconds Pure water supply: About 2L / min

  The substrate to be cleaned was cleaned by a cleaning method described later using each diluent (cleaning composition of embodiment 2), and the cleaning properties of each diluent (cleaning composition of embodiment 2) on silica fine particles were evaluated. .

4). Cleaning Method Using Cleaning Agent Composition The substrate to be cleaned was cleaned under the following conditions with a cleaning device (three-stage type: first-stage roll brush-2 stage roll brush-3 stage ultrasonic shower).
(A) Cleaning: A substrate to be cleaned set in a cleaning device is set at a transport standby position, and then a single substrate to be cleaned is transported to a location where the first stage roll brush of the cleaning device is present to be cleaned. A rotating roll brush was pressed against each of the main surfaces of the substrate, and the diluted solution (25 ° C.) was washed for 7 seconds while being injected onto each of the main surfaces of the substrate to be cleaned. The supply amount of the diluent was 24.5 g / 7 seconds.
(B) Rinsing: The substrate to be cleaned after being washed with the diluting liquid is transported to a place where the second-stage roll brush of the cleaning apparatus is present, and then the substrate to be cleaned, as in the case of the cleaning in (a). A rotating roll brush was pressed against each of the two main surfaces, and rinsing was performed for 7 seconds while injecting ultrapure water at 25 ° C. onto each of the two main surfaces of the substrate to be cleaned. Thereafter, the substrate to be cleaned is transported to a third-stage ultrasonic shower, and rinsed for 7 seconds while injecting 25 ° C. ultrapure water applied with 950 kHz ultrasonic waves onto each of the two main surfaces of the substrate to be cleaned. It was. The supply amount of ultrapure water at 25 ° C. to which 950 kHz ultrasonic waves were applied was 105 g / 7 seconds.
(C) Drying: After washing, the substrate after rinsing held by the spin chuck was rotated at high speed (peripheral peripheral speed: 1.5 m / s) and dried for 1 minute.

5. Evaluation of detergency of silica fine particles The detergency of each diluted solution was evaluated by examining the number of remaining silica fine particles on the surface of the substrate after the washing through the steps (a) to (c) by a method described later. The results are shown in Tables 1 and 2.

  Using a scanning electron microscope (S-4800, manufactured by Hitachi High-Technologies Corporation), the substrate after drying is observed at a magnification of 5,000 times (field range: 20 μm square) and observed in the observation field. The number of silica fine particles remaining on the surface was counted. This observation was performed (10 points at random on both main surfaces of the substrate), and a total of 100 points (10 points × 2 × 5 = 100 points) were performed on the five substrates. Based on the total number of fine particles observed at 100 points and evaluation criteria described later, the detergency of the silica fine particles was evaluated in seven stages. The smaller the number of silica fine particles, the better the detergency.

(Evaluation criteria for cleanability of fine particles)
Level A: The total number of fine particles is zero.
Level B: The total number of fine particles is 1-2.
Level C: The number of all fine particles is 3 to 4.
Level D: The total number of fine particles is 5-6.
Level E: The total number of fine particles is 7-8.
Level F: The total number of fine particles is 9-10.
Level G: The total number of fine particles is 11 or more.

  From the results described in Table 1 and Table 2, when the total weight of the components other than the water (component (C)) is 100% by weight, the content of the component (B) is 30 to 95% by weight, and The diluents of Examples 1 to 8 in which the weight ratio {component (A) / component (B)} is 0.04 to 0.8 are more cleanable and resistant to foaming than the diluent of the comparative example. It was confirmed that it was excellent.

  In particular, for the diluted solution of Example 8, it is considered that the solubility of the silica fine particles is increased by adjusting the pH to 13.8. Moreover, since the dilution liquid of Example 8 also contains a chelating agent, it is thought that precipitation of Ni is suppressed. For this reason, it is thought that the washing | cleaning property is excellent rather than the dilution liquid of another Example.

  Further, in Comparative Example 10 containing a nonionic surfactant, since the rinsing property is poor due to the inclusion of the nonionic surfactant, the content of the component (B) in the total weight of the components other than the component (C) is included. Even when the amount was within a range of 30 to 95% by weight and the weight ratio {component (A) / component (B)} was within a range of 0.04 to 0.8, the detergency was poor.

In addition, the detail of each component in Table 1 and Table 2 is as below-mentioned.
[Component (A)]
Aqueous solution of sodium salt of acrylic acid / 2-acrylamido-2-methylfluorosulfonic acid (92/8 (molar ratio)) copolymer compound (weight average molecular weight 12,000) (solid content 40 wt%)
[Component (B)]
N- (β-aminoethyl) ethanolamine (manufactured by Wako Pure Chemical Industries, Wako Grade 1)
Diethylenetriamine (manufactured by Wako Pure Chemical Industries, deer special grade)
Triethylenetetramine (manufactured by Kanto Chemical Co., Inc.)
[Optional ingredients]
(Component (D))
1-Hydroxyethylidene-1,1-diphosphonic acid in water (Solucia, Dyquest 2010R, 60% solids)
(Ingredient (E))
Aqueous solution of potassium hydroxide (manufactured by Kanto Chemical Co., Inc., deer grade, solid content 48% by weight)
[Other ingredients]
Monoethanolamine (Wako Pure Chemical Industries, Wako Grade 1)
Methyldiethanolamine (Kishida Chemical Co., 1st grade)
Nonionic surfactant (Emogen LS-110, manufactured by Kao Corporation)
Aqueous solution of sodium P-toluenesulfonate (manufactured by Meitomo Sangyo Co., Ltd., solid content 90% by weight)

  By using the cleaning composition of the present invention as it is or diluted as necessary to clean the surface of the substrate to be cleaned, an HD substrate having a high cleanliness can be obtained even in a short cleaning time. . Therefore, the present invention can contribute to an improvement in product yield.

Claims (7)

The ratio (molar ratio) between the structural unit derived from acrylic acid and the structural unit derived from 2-acrylamido-2-methylpropanesulfonic acid is 91/9 to 95/5, and the structural unit derived from acrylic acid and 2 -Copolymerized compound and / or salt thereof (component (component (%)) of the total proportion of the structural units derived from acrylamido-2-methylpropanesulfonic acid in all the structural units
A))
A polyamine (component (B));
Water (component (C)),
Substantially free of nonionic surfactants,
Content of the said component (B) in the sum total of the weight of components other than the said component (C) is 30 to 95 weight%,
The weight ratio {component (A) / component (B)} of the component (A) and the component (B) is 0.04 to 0.8.
The
The component (B) is ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, neopentanediamine, 3-methylaminopropylamine, diethylenetriamine, dipropylenetriamine, triethylenetetramine, N- (β-amino ethyl) ethanolamine, or Ru Oh amino ethyl isopropanolamine, hard board detergent composition having a Ni-P-containing layer.   The cleaning composition for hard disk substrates having the Ni-P-containing layer according to claim 1, further comprising a chelating agent.   The cleaning composition for a substrate for a hard disk having a Ni-P-containing layer according to claim 2, wherein the chelating agent is a phosphonic acid.   The cleaning composition for a substrate for a hard disk having a Ni-P-containing layer according to any one of claims 1 to 3, wherein the pH at 25 ° C is 9 to 14. The hard disk having a Ni-P-containing layer according to any one of claims 1 to 4, wherein the content of the component (A) in the total weight of the components other than the component (C) is 5 to 50% by weight. Cleaning composition for substrates.   The hard disk substrate having a Ni-P-containing layer according to any one of claims 1 to 5, wherein the weight ratio {component (A) / component (B)} is 0.4 to 0.5. Cleaning composition.   The substrate to be polished is obtained by polishing the substrate to be cleaned with a polishing composition containing silica fine particles and then rinsing with water to obtain the substrate to be cleaned, and the substrate to be cleaned according to any one of claims 1 to 6. The manufacturing method of the board | substrate for hard disks which has a Ni-P containing layer including the process of wash | cleaning using a cleaning composition.