JP5208409B2 - Cleaning composition - Google Patents

Description

  The present invention relates to a cleaning composition. The cleaning composition of the present invention is suitably used for cleaning hard surfaces constituting fine gaps. The fine gap is preferably applied to one having a gap of 0.003 to 0.3 mm, more preferably 0.005 to 0.2 mm. For example, it is used for cleaning gaps after slicing a silicon wafer, cleaning liquid crystal gaps at the end of a liquid crystal panel, cleaning flux gaps after mounting a printed circuit board, and the like. Among these, it is suitably used for cleaning a gap after slicing a silicon wafer. Examples of the silicon wafer include various silicon wafers such as a solar cell silicon wafer and a semiconductor silicon wafer.

  The cleaning composition of the present invention is particularly useful as a cleaning composition for silicon wafers, and the cleaning composition of the present invention is suitably used for a method for producing a silicon wafer. Silicon wafers have a narrow gap of 0.3 mm between wafers after slicing and are required to have a function of quickly allowing a cleaning component to permeate dirt remaining in the gap. The cleaning composition of the present invention requires such a cleaning composition. It is suitably used as a cleaning composition for silicon wafers that require functions.

  Conventionally, water-soluble alkaline agents such as sodium hydroxide, potassium hydroxide, sodium orthosilicate and sodium metasilicate have been used for various applications such as acid neutralization, saponification of fats and oils, and washing of oily soils. ing. In addition, nonionic surfactants have penetrability, emulsification properties, and dispersibility, are useful as active ingredients of various cleaning agents, and are suitable for cleaning hard surfaces such as metals, glass, and fibers. Therefore, by using a combination of an alkaline agent and a nonionic surfactant, an excellent strong alkaline detergent having penetrability, emulsifying property, dispersibility, and detergency can be obtained.

  Various cleaning agents are used for cleaning dirt on the hard surface constituting the fine gap. For example, in a method for manufacturing a silicon wafer, after a slicing step of turning a silicon crystal ingot into a wafer, in order to remove the lubricating oil used in the slicing step and prevent reattachment of abrasive grains, these are used. A cleaning step of removing with a cleaning agent is performed. Also in the cleaning step, a cleaning composition containing the alkaline agent and a nonionic surfactant is used.

In addition, the alkaline detergent composition has been conventionally used as two liquids in use, but for the purpose of improving handleability, a specific carboxylic acid or sulfone is added to an alkaline agent and a nonionic surfactant. A high-concentration detergent composition that has been made into one component by blending an acid salt as a solubilizer has been proposed (Patent Document 1). However, for such low-temperature storage stability, for example, polyoxyethylene (hereinafter referred to as POE) / polyoxypropylene (hereinafter referred to as POP) alkyl ether, POE / POP alkylphenyl ether, POE / POP / POE alkyl ether, POE A nonionic surfactant such as POP / POE alkylphenyl ether is used (Patent Document 2).
JP-A-60-161728 JP 2004-182801 A

  However, with an alkaline detergent composition that has been liquefied using one of these nonionic surfactants, sufficient cleaning properties can be obtained in the cleaning of hard surface dirt that constitutes the fine gaps, particularly in the cleaning step of the silicon wafer manufacturing method. It could not be said that it had. Further, the one-component alkaline detergent composition has a problem of being precipitated as crystals below freezing when stored outdoors in winter.

  The present invention has good cleanability of dirt on the hard surface constituting the fine gap, in particular, good cleanability of dirt remaining in the wafer gap in the cleaning process when manufacturing a silicon wafer, and low-temperature storage stability. An object of the present invention is to provide a one-component alkaline detergent composition having

  The present invention also provides a method for cleaning a hard surface constituting a fine gap by using the cleaning composition, and further provides a silicon wafer having a small residual oil content by using the cleaning composition. The object is to provide a method of manufacturing.

That is, the present invention is a hard surface cleaning composition constituting a fine gap,
(A) alkaline agent,
(B) the general formula ^{(I): R 1 -O- (} EO) m H
(Wherein R ¹ is a 2-ethylhexyl group, EO is an oxyethylene group, and the average added mole number m is a number of 5 to 12),
(C) the general formula _{^{(II): R 2 -X- (}} CH 2) n COOM 1
(In the formula, R ² is a saturated or unsaturated linear or branched aliphatic hydrocarbon group having 4 to 18 carbon atoms, or an aromatic hydrocarbon group having 5 to 18 carbon atoms, and X is >NH,> N (CH ₂ ) _n COOM ¹ , or> CHCOOM ¹ , where M ¹ is a hydrogen atom, an alkali metal, or an aliphatic amine, ammonium or alkanolamine having 1 to 4 carbon atoms, n Is an integer of 1 to 3), and a detergent composition containing water.

  The present invention also relates to a method for cleaning a hard surface constituting a fine gap, wherein the hard surface constituting the fine gap is washed with the cleaning composition.

Further, the present invention is a method for producing a silicon wafer, comprising a slicing step for making a wafer with a silicon crystal ingot temporarily fixed with an adhesive, a cleaning step for the sliced wafer, and an etching step for the cleaned wafer,
The said cleaning process is related with the manufacturing method of a silicon wafer which has the process of wash | cleaning the said wafer using the said cleaning composition in the state which temporarily fixed the some sliced wafer with the adhesive agent.

  The present invention has good cleanability of dirt on hard surfaces constituting fine gaps, in particular, good cleanability in the cleaning process when manufacturing silicon wafers, and good one-packability, and low-temperature storage stability. A cleaning composition can be provided.

  Further, the present invention can provide a method for cleaning a hard surface constituting a fine gap by using the cleaning composition, and further, a silicon wafer having a small residual oil content using the cleaning composition. Can be provided.

  As the (a) alkaline agent of the present invention, any water-soluble alkaline agent can be used in order to ensure the removal of oil stains. Specific examples include hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide, silicates such as sodium orthosilicate, sodium metasilicate and sodium sesquisilicate, phosphates such as trisodium phosphate, disodium carbonate And carbonates such as sodium hydrogen carbonate and dipotassium carbonate, and borate salts such as sodium borate. Two or more water-soluble alkaline agents may be combined. Sodium hydroxide, potassium hydroxide, sodium orthosilicate and sodium metasilicate are preferred, sodium hydroxide and potassium hydroxide are more preferred, and sodium hydroxide is still more preferred.

The nonionic surfactant (b) used in the present invention has the general formula (I): R ¹ —O— (EO) _m H (wherein R ¹ is a 2-ethylhexyl group and EO is an oxyethylene group) The average added mole number m is a number of 5 to 12.). The detergent composition of the present invention has good detergency of dirt on hard surfaces constituting fine gaps by using the nonionic surfactant represented by the general formula (I). . For example, the cleanability of the gap after slicing the silicon wafer, the cleanability of the liquid crystal gap at the end of the liquid crystal panel, and the cleanability of the flux gap after mounting the printed circuit board are good. In particular, the cleaning performance in the cleaning process when manufacturing a silicon wafer is good. Furthermore, among silicon wafers, the cleaning performance in the cleaning process when manufacturing a solar cell silicon wafer having a wide hard surface that is sliced with a small thickness and forms a gap is good. And the cleaning composition of this invention has implement | achieved the cleaning composition which has favorable one-component property and has low-temperature storage stability.

In the above general formula (I), R ¹ is a 2-ethylhexyl group, and by selecting a 2-ethylhexyl group as the hydrophobic group of the nonionic surfactant, a cleaning agent that can satisfy cleaning properties and low-temperature storage stability A composition is obtained.

  Moreover, although an oxyethylene group has distribution by addition mole number, the average addition mole number m is 5-12 from the point of detergency. The average added mole number m is preferably 6-10.

The compound (c) used in the present invention has the general formula (II): R ² —X— (CH ₂ ) _n COOM ¹ (wherein R ² is a saturated or unsaturated straight chain having 4 to 18 carbon atoms, or A branched aliphatic hydrocarbon group or an aromatic hydrocarbon group having 5 to 18 carbon atoms, X is>NH,> N (CH ₂ ) _n COOM ¹ or> CHCOOM ¹ ; ¹ is a hydrogen atom, an alkali metal, or an aliphatic amine, ammonium or alkanolamine having 1 to 4 carbon atoms, and n is an integer of 1 to 3). By using the compound as a solubilizer, a one-component cleaning composition can be obtained.

Examples of the alkali metal represented by M ¹ include potassium and sodium, examples of the aliphatic amine having 1 to 4 carbon atoms include methylamine, ethylamine, propylamine, butylamine, ethylenediamine, and diethylenetriamine. Examples of the alkanolamine include monoethanolamine. , Diethanolamine, triethanolamine, and other alkanolamines having 2 to 10 carbon atoms. In these, sodium is preferable from a viewpoint that solubilization is more excellent.

Specific examples of the compound (c) include the following. In the following (Chemical Formula 1), M ¹ has the same meaning as described above.

  Among the above compounds, 2-ethylhexylaminodipropionate described above is preferable from the viewpoint of excellent solubilization.

  The cleaning composition of the present invention comprises (a) an alkaline agent, (b) a nonionic surfactant represented by the general formula (I), and (c) a solubilizer represented by the general formula (II). It is prepared by further blending water with the above compound. Furthermore, optional additives are added.

  The amount of the component (b) is blended based on the component (a), and is preferably 0.01 to 8.5 parts by weight, more preferably 0.02 to 1 part by weight of the component (a). 7 parts by weight, more preferably 0.02 to 5 parts by weight. When the blending amount of the component (b) is 0.01 parts by weight or more, the component (b) in the composition is maintained at a concentration necessary for washing. Moreover, the solubility of the component (b) which is a nonionic surfactant is favorable in it being 8.5 weight part or less.

  The blending amount of component (c) is the weight ratio {((a) + (b)) of the total amount of component (a) and component (b) ((a) + (b)) to component (c). ) / (C)} is preferably 50/1 to 3/1, more preferably 30/1 to 3/1, and further preferably 20/1 to 3/1. By setting the weight ratio within the above range, it is possible to satisfy one-liquidity and low-temperature storage stability while ensuring cleanability.

  The cleaning composition of the present invention can further contain (d) a chelating agent. Examples of chelating agents include alkali metal salts or lower amine salts of aldonic acids such as glyceric acid, tetronic acid, pentonic acid, hexonic acid, heptonic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid, ethylenediaminediacetic acid, tetraethylenetetraminehexaacetic acid, etc. Alkali metal salt or lower amine salt of aminocarboxylic acid, alkali metal salt or lower amine salt of oxycarboxylic acid such as citric acid, malic acid, aminotrimethylenephosphonic acid, hydroxyethylidene diphosphonic acid, ethylenediaminetetramethylenephosphonic acid, Preferred examples include alkali metal salts or lower amine salts of phosphonic acids such as diethylenetriaminepentamethylenephosphonic acid, and alkanolamine salts such as monoethanolamine, diethanolamine, and triethanolamine. Is an alkali metal salt or lower amine salt of gluconic acid, glucoheptonic acid, ethylenediaminetetraacetic acid, citric acid, malic acid, hydroxyethylidene diphosphonic acid, more preferably sodium gluconate, sodium glucoheptonate, sodium ethylenediaminetetraacetate, Sodium citrate and sodium hydroxyethylidene diphosphonate are preferable, and sodium ethylenediaminetetraacetate is more preferable. (D) As the chelating agent, at least one of these may be used, and two or more may be used in combination.

  By blending the component (d), the detergency can be improved. The amount of component (d) is preferably 4 parts by weight or less with respect to 1 part by weight of component (a). More preferably, it is 0.01-4 weight part, More preferably, it is 0.1-2 weight part. The detergency can be improved by setting the amount of component (d) to 0.01 parts by weight with respect to 1 part by weight of component (a).

  Moreover, the cleaning composition of this invention can mix | blend arbitrary additives other than the said component further. Examples of the additive include a water-soluble polymer carboxylic acid represented by the following general formula (Chemical Formula 2) and an additive for preventing reattachment of dirt (chips and abrasive grains) remaining during the slicing step; Examples thereof include alkali metal salts and amine salts.

R _{1 to} R ₆ in the above formulas represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxyl group having 1 to 5 carbon atoms, COOM, and OH, and may be the same or different. M is a hydrogen atom, an alkali metal, an alkylamine having 1 to 4 carbon atoms, or an alkanolamine having 1 to 6 carbon atoms. Although both ends of the general formula represented by Chemical Formula 2 are not particularly limited, a hydrogen atom, OH, an alkyl group having 1 to 5 carbon atoms, an alkoxyl group having 1 to 5 carbon atoms or SO ₃ M (M is as defined above And the like may be the same or different. m ¹ and n ¹ each represent the number of moles of the monomer in parentheses, and m ¹ may be 0. When m ¹ is 0, it is a homopolymer of a monomer whose number of moles is represented by n ¹ . m ¹ and copolymerization molar ratio ^m 1 / ^{n 1} of ^{n 1} is preferably 0 / 10-10 / 1, a weight average molecular weight (MW) is preferably 1,000 to 100,000, more preferably It is 3,000 to 50,000, more preferably 5,000 to 20,000. The general formula is shown in block form for convenience, but the polymerization form may be block or random. Specific examples include acrylic acid homopolymer, acrylic acid-maleic acid copolymer, α-hydroxyacrylic acid homopolymer, C ₅ olefin-maleic acid copolymer, isobutylene-maleic acid copolymer, and alkalis thereof. Examples thereof include metal salts and amine salts. Acrylic acid homopolymer and acrylic acid-maleic acid copolymer are preferred. Specific product names include Poise 540, Poise 530, Poise 521, Poise 520 manufactured by Kao Corporation, Pale Plaque 250 manufactured by Nippon Peroxide Co., Ltd., Pale Plaque 1200, Pale Plaque 5000, and Quinn Flow 540 manufactured by Nippon Zeon Co., Ltd. , Quinnflow 542, Quinnflow 543, Quinnflow 560, Quinnflow 640, Quinnflow 750, Aron T-40 made by Toagosei Co., Ltd., Isoban 06 made by Kuraray Co., Ltd., Isoban 04, Isoban 600, Aqua made by Nippon Shokubai Co., Ltd. Rick DL100 etc. are mentioned. Two or more water-soluble polymer carboxylic acids may be combined.

The weight average molecular weight is a value calculated based on a peak in a chromatogram obtained by applying a gel permeation chromatography (GPC) method under the following conditions.
Column: G4000PWXL + G2500PWXL (Tosoh Corporation)
Eluent: (0.2 M phosphate buffer) / (acetonitrile) = 9/1 (volume ratio)
Flow rate: 1.0 mL / min
Column temperature: 40 ° C
Detector: RI detector Sample size: 0.2 mg / mL
Reference material: Polyethylene glycol equivalent

  The amount of the additive is preferably 10 parts by weight or less with respect to 1 part by weight of the component (a). More preferably, it is 0.02-10 weight part, More preferably, it is 0.2-3 weight part. The solubilizing property of the component (b) is improved by setting the amount of the additive to be 10 parts by weight or less with respect to 1 part by weight of the component (a). Moreover, the washing | cleaning property of an abrasive grain can be improved by making the compounding quantity of the said additive into 0.02 weight part with respect to 1 weight part of a component (a).

  The cleaning composition of the present invention is usually prepared as a concentrated product so as to be suitable during storage. Water is used as the solvent. As water used for the solvent of the composition of the present invention, deionized water is desirable. The concentration in the cleaning composition can be controlled by water. The concentrated product can be further diluted with water when used in the washing step. The cleaning composition of the present invention has good one-component properties and can be stored in advance as one solution in the cleaning process.

  The cleaning composition of the present invention comprises (a) an alkaline agent, (b) a nonionic surfactant represented by the general formula (I), and (c) a compound represented by the general formula (II), (D) The total amount of component (a) and component (b) in the composition based on the total amount of the chelating agent, optional additives, and the composition with the balance being the solvent (preferably water) (A) + (b)) is usually adjusted to 0.1 to 30% by weight in the composition. Furthermore, it is preferable that it is 0.3-25 weight%, Furthermore, it is preferable that it is 0.4-20 weight%.

  When the composition is a concentrated product, the total amount ((a) + (b)) of the component (a) and the component (b) in the composition is preferably 2 to 30% by weight, more preferably It is prepared to be 5 to 25% by weight, more preferably 5 to 20% by weight. When the total amount is 30% by weight or less, it is also preferable from the viewpoint of stability as a concentrated product. Further, when it is 2% by weight or more, the storage efficiency of the cleaning agent and an appropriate dilution ratio are ensured and the handling is easy.

  In diluting the cleaning composition (concentrated product) during the cleaning step, the degree of dilution can be set as appropriate. From the standpoint of ensuring cleaning properties in the cleaning step, component (a) and component The total amount of (b) ((a) + (b)) is 0.1 to 10% by weight, more preferably 0.3 to 5% by weight, and further 0.4 to 2% in the composition as a diluent. It is preferable that it is weight%.

  The cleaning composition of the present invention is used for cleaning hard surfaces constituting various fine gaps as described above, preferably 0.003 to 0.3 mm, more preferably 0.005 to 0.2 mm. However, it is particularly suitable for cleaning silicon wafers. Hereinafter, the case where it uses as a cleaning agent for silicon wafers is explained as a typical example of the cleaning composition of the present invention. Specifically, the silicon wafer cleaning agent is a silicon wafer having a slicing process, a slicing wafer cleaning process, and a cleaned wafer etching process in which a silicon crystal ingot is temporarily fixed with an adhesive. It is used in the cleaning step in the manufacturing method.

  The silicon wafer manufacturing method in which the slicing step, then the cleaning step, and then the etching step are performed is suitably applied in the solar cell silicon wafer manufacturing method.

  In the slicing step, for example, the silicon crystal ingot is temporarily fixed with an adhesive and cut into a predetermined thickness. That is, the silicon crystal ingot held over the entire length by the adhesive on the holding base is cut so as to form a plurality of wafers in a thin plate shape in a direction crossing the axis of the ingot. As the adhesive, an epoxy resin is usually used. Lubricating oil, abrasive grains, etc. are used for cutting. As a cutting method, an inner peripheral blade or a wire saw is used. A wire saw has a small cutting allowance and can cut several hundred pieces at a time, so it has a high slicing speed and is advantageous in terms of cost. Since silicon wafers can reduce the cost per chip, a large diameter (12 inches) is about to be the center. Wire saws are suitable for large diameter wafers. A wire saw presses and cuts a silicon crystal ingot against a wire while applying a machining fluid (slurry) in which abrasive grains are dispersed in slice oil to hundreds of running wires.

  Next, a cleaning process is performed on the sliced wafer. For example, the cleaning process is performed in a state where a plurality of sliced wafers are temporarily fixed to the holding base with an adhesive. In the cleaning process, dirt (cutting oil, chips, abrasive grains) existing between the wafers is removed. In the cleaning step, the cleaning composition of the present invention is used. The cleaning composition of the present invention has good cleaning properties as described above.

  Next, an etching process is performed on the cleaned wafer. The etching step in the method for producing a solar cell silicon wafer is a step of making the wafer surface uneven in order to increase the conversion efficiency. Usually, an alkaline solution, preferably an aqueous solution of 3 to 5% by weight of sodium hydroxide, It is performed by immersing at ˜90 ° C. for 1 minute to 30 minutes.

  In the semiconductor wafer silicon manufacturing method, in the silicon wafer manufacturing method, a sliced wafer cleaning process and an etching process have a lapping process of the cleaned wafer, and the etching process is followed by an etching process. And polishing the finished wafer. That is, in the semiconductor wafer silicon manufacturing method, a silicon crystal ingot is temporarily fixed with an adhesive, and a slicing process for forming a wafer, a slicing wafer cleaning process, a cleaned wafer wrapping process, and a wrapping wafer etching process. And polishing the etched wafer. In the slicing step and the washing step, the same operations as described above are performed.

  In the semiconductor wafer silicon manufacturing method, a lapping process is performed on a cleaned wafer. The lapping process is performed in order to remove the distortion of the sliced wafer and smooth the surface of the wafer. In the lapping step, for example, polishing with abrasive grains is performed while sandwiching and rotating the wafer between two upper and lower surface plates.

  Next, an etching process is performed on the lapped wafer. The etching process in the semiconductor wafer silicon manufacturing method is performed to remove the crushed layer generated in the lapping process and to make the wafer highly flat. In the etching step, the etching is usually performed by dipping in an acid etching solution or an alkali etching solution, preferably an aqueous solution of 0.5 to 4% by weight of sodium hydroxide at 40 to 80 ° C. for 1 to 30 minutes. Do.

  Next, a polishing process is performed on the etched wafer. In the polishing process, the smoothness of the wafer is improved by mirror polishing. In the polishing process, mechanical polishing and chemical polishing can be performed using both an abrasive solution and an alkali solution as a chemical polishing agent. Note that, after the polishing step, metal particles on the wafer surface are appropriately removed by cleaning.

<Detergency>
The following evaluation was performed about the detergent composition prepared in each case. 50 ml of the detergent composition is put in each of 6 50 ml beakers, and 6 locations (2 rows, 3 rows) in the tank (filled with water) of the ultrasonic cleaning device (UT-204 manufactured by Sharp Corporation). Column). After heating the cleaning composition in the beaker to 60 ° C., the wedge-shaped cell (glass uses KCRK-07 manufactured by EHC Co., Ltd.) and oil (for solar cell silicon wafer) are shown in FIG. A sample in which 0.1 g of cutting oil was injected was immersed in the cleaning composition in each of the beakers, and six samples were prepared. The sample was subjected to ultrasonic cleaning (frequency: 39 kHz, output: 200 W) at 60 ° C. for 5 minutes. After the washing, the wedge-shaped cell is taken out, the area image of the oil adhering to the cell is magnified by 2 magnifications, the area is replaced with a grid of grid paper (1 mm square), and the grid where oil is present From the total area (the area of 1 mass was counted if oil was present even in a part of 1 mass), the residual ratio of oil was calculated by the following formula. Table 1 shows the average values measured for six samples.
Residual ratio of oil (%) = (area of oil adhering to cell after washing / area of oil adhering to cell before washing) × 100
The criteria for cleanability are:
A: Oil residual ratio is 0 to 20%
○: Oil residual ratio is over 20 to 40%
(Triangle | delta): The residual ratio of oil exceeds 40 to 60%
X: Oil residual ratio is more than 60 to 100%

<One liquefaction>
Concentrated cleaning composition having the same composition as the cleaning composition prepared in each example (20 times the components excluding ion-exchanged water) was stirred for 30 minutes at 30 to 40 ° C. The state was evaluated according to the following criteria.
○: Transparent and uniform without turbidity and precipitation.
X: There exists turbidity or precipitation.

<Storage stability>
In the evaluation of the one-component property described above, the cleaning composition having the one-component property of “◯” was further stored at −5 ° C. for one month, and then visually checked for crystals and turbidity. Evaluation was made according to the following criteria.
○: There is no crystal and turbidity.
X: There exists a crystal | crystallization or cloudiness.

Example 1
Sodium hydroxide 0.17% by weight,
Polyoxyethylene (8 mol) 2-ethylhexyl ether 0.8% by weight
Sodium 2-ethylhexylaminodipropionate 0.3% by weight,
Sodium ethylenediaminetetraacetate 0.05% by weight
And the cleaning composition which consists of remaining water (a balance amount uses deionized water) was prepared, and the said evaluation was performed. The results are shown in Table 1.

Examples 2-5, Comparative Examples 1-8
A cleaning composition was prepared in the same manner as in Example 1 except that the type of each component and the blending ratio thereof were changed as shown in Table 1 in Example 1. The evaluation results are shown in Table 1.

In Table 1, b-1: polyoxyethylene (8 mol) 2-ethylhexyl ether,
b-2: polyoxyethylene (4 mol) 2-ethylhexyl ether,
b-3: polyoxyethylene (6 mol) 2-ethylhexyl ether,
b-4: polyoxyethylene (10 mol) 2-ethylhexyl ether,
b-5: polyoxyethylene (13 mol) 2-ethylhexyl ether,
b-6: polyoxyethylene (6 mol) tridecyl ether,
b-7: polyoxyethylene (8 mol) octyl ether,
b-8: polyoxyethylene (5 mol) polyoxypropylene (2 mol) polyoxyethylene (5 mol) secondary dodecyl alcohol ether. The average number of moles added is in parentheses.

  The average addition mole of polyoxyethylene alkyl ether was measured using a sample prepared by dissolving 3% by weight of a predetermined polyoxyethylene alkyl ether in isopropyl alcohol under the following apparatus and column measurement conditions.

GC device: 6850SERIESII manufactured by Agilent Technologies
Column: Agilent 19091A-102EULTRA 1 Methylsiloxane Measurement conditions: Initial: 60 ° C., hold for 2 minutes, heating rate: 10 ° C./min, 300 ° C .: hold for 20 minutes

  The weight% of each oxyethylene group adduct was a value obtained by dividing the detection peak area of the target oxyethylene group adduct by the total peak area. In addition, the horizontal axis represents the number of moles of the oxyethylene group adduct obtained by the above method, the vertical axis represents the cumulative weight% of the oxyethylene group adduct, and the weight% of the oxyethylene group adduct is represented by a cumulative distribution. The number of moles of the oxyethylene group adduct having a weight% of 50% by weight was defined as the average number of moles of polyoxyethylene alkyl ether added.

  From the results shown in Table 1, the cleaning compositions of Examples 1 to 5 have good cleaning properties, and have one-pack properties and low-temperature storage stability. On the other hand, in Comparative Examples 1 and 2, polyoxyethylene alkyl ether is used as the nonionic surfactant, but the average number of moles of oxyethylene group added is not in the range of 5 to 12, and the detergency is satisfied. Not. Comparative Example 3 does not contain a nonionic surfactant, and Comparative Example 4 does not contain an alkaline agent and does not satisfy the cleaning property. In Comparative Examples 5 and 6, polyoxyethylene alkyl ether is used as the nonionic surfactant. However, since the hydrophobic group is not a 2-ethylhexyl group, the low-temperature storage stability is not satisfied. In Comparative Example 5, the cleaning property is not satisfied. In Comparative Example 7, a polyoxyalkylene alkyl ether having a polyoxypropylene group in addition to an oxyethylene group is used as the nonionic surfactant, and the cleaning property is not satisfied. In Comparative Example 8, a solubilizer is not used, and the one-component property and the low-temperature storage stability are not satisfied.

It is a figure which shows the wedge-shaped cell for evaluating the washability in an Example.

Claims (8)

A cleaning composition for silicon wafers ,
(A) an alkali metal hydroxide ,
(B) the general formula ^{(I): R 1 -O- (} EO) m H
(Wherein R ¹ is a 2-ethylhexyl group, EO is an oxyethylene group, and the average added mole number m is a number of 5 to 12),
(C) the general formula _{^{(II): R 2 -X- (}} CH 2) n COOM 1
(In the formula, R ² is a saturated or unsaturated linear or branched aliphatic hydrocarbon group having 4 to 18 carbon atoms, or an aromatic hydrocarbon group having 5 to 18 carbon atoms, and X is >NH,> N (CH ₂ ) _n COOM ¹ , or> CHCOOM ¹ , where M ¹ is a hydrogen atom, an alkali metal, or an aliphatic amine, ammonium or alkanolamine having 1 to 4 carbon atoms, n Is an integer of 1 to 3), and a detergent composition containing water.   The cleaning composition according to claim 1, wherein the total amount of component (a) and component (b) ((a) + (b)) is 0.1 to 30% by weight in the composition.   The weight ratio {((a) + (b)) / (c)} of the total amount of component (a) and component (b) ((a) + (b)) to component (c) is 50/1. The cleaning composition according to claim 1, which is ˜3 / 1.   Furthermore, the cleaning composition in any one of Claims 1-3 containing (d) chelating agent. A method for cleaning a silicon wafer , wherein the silicon wafer is cleaned using the cleaning composition according to claim 1. A silicon wafer manufacturing method comprising a slicing step of turning a silicon crystal ingot into a wafer, a cleaning step of the sliced wafer, and an etching step of the cleaned wafer,
The said washing | cleaning process wash | cleans the said wafer using the cleaning composition for silicon wafers in any one of Claims 1-4 in the state which temporarily fixed the some sliced wafer with the adhesive agent. A method for manufacturing a silicon wafer. The method for manufacturing a silicon wafer according to claim 6 , wherein the silicon wafer is a solar cell silicon wafer. The silicon wafer is a semiconductor silicon wafer,
7. The silicon wafer according to claim 6 , further comprising a lapping step for the cleaned wafer between the cleaning step and the etching step for the sliced wafer, and further comprising a polishing step for the etched wafer after the etching step. Manufacturing method.