JP2003292562A - Cleaning brush - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning brush having physical properties such as hardness, abrasion resistance, tear strength and the like to be suitably used for cleaning manufacturing equipment after chemical mechanical polishing of semiconductor wafers, the so called after cleaning of CMP, by using a polyurethane foam having physical properties such as hardness, abrasion resistance and the like in a predetermined range as a material for the cleaning brush. <P>SOLUTION: A polyurethane is produced by mixing a polyether polyol which is a main polyol in a polyol component and has ≤30 pts.wt. addition rate in the internal ratio of an ethylene oxide expressing hydrophilicity and reactivity and a polymer polyol which is one of ingredients of the polyol component and contains a vinyl monomer with an isocyanate component having 80-150 isocyanate index and a nonmetal-based catalyst such as an amine catalyst or the like. The polyurethane foam having a uniform three dimensional net structure is produced by using the polyurethane with setting Asker F hardness to 50-95 and a weight change rate for expressing abrasion resistance (in accordance with JIS K 7204) to ≤3.5%. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning brush, and more particularly to a surface of liquid crystal, PDP (plasma display), various optical devices, glass for glass and hard disk, especially a surface of a semiconductor wafer with high accuracy. Chemical mechanical polishing (Che
The present invention relates to a cleaning brush that can be suitably used for cleaning semiconductor wafers and the like that are subjected to mical mechanical polishing (CMP) after polishing.

[0002]

2. Description of the Related Art The sophistication of information technology equipment such as computers is an important technology that supports recent breakthroughs in technology. The sophistication of the information technology is based on the CPU (central processing unit) of the information equipment used, that is, the CP.
It is no exaggeration to say that this has been achieved by increasing the performance and integration of the VLSI devices that make up U. As one of the methods capable of greatly improving the high performance and the high integration, the high integration of the VLSI in the horizontal direction, that is, the miniaturization of elements is pursued, while the high integration of the vertical direction is also performed. Multiplexing of wiring is being implemented.

The most important factor in the wiring multiplexing is to secure the depth of focus (DOF) of photolithography when exposing a wiring pattern of a metal wiring such as an interlayer insulating film or a wiring metal film described later, that is, the surface. Is smaller than the depth of focus of the pattern exposure, and therefore highly accurate flattening is required. This is because in the process of forming a multi-layered wiring in which wirings are multiplexed, if there is a certain level of unevenness in the interlayer insulating film or wiring metal film, focusing cannot be performed sufficiently or a fine wiring structure is formed. Is impossible.

The achievement of the highly accurate flattening described above is achieved by the conventional S
It is difficult to use OG (Spin on Glass) or etch back, and ultra-precision polishing such as CMP (Chemical Mechanical Polishing) is becoming common as an alternative method. The CM
The planarization by P is performed by elastic polishing with an abrasive in which fine particles such as silica and alumina are mixed and dispersed in an aqueous solution having alkaline or acidic chemical erosion on the surface to be polished of a flat object such as a semiconductor wafer. It is carried out by using a material.

The planarization by CMP is carried out every time a required circuit pattern is formed on the object to be flattened, and usually the circuit pattern is formed several times to several tens of times until the circuit pattern to be obtained is obtained. -The flattening is repeated. When the flattening process is completed, so-called shavings, abrasives, and other polishing impurities, such as impurities such as metal or organic substances, generated by the flattening are generated on the object to be flattened for each process. It will remain. Therefore, it is necessary to remove the polishing debris remaining on the object to be flattened in preparation for the next circuit pattern formation each time one batch of the circuit pattern formation-planarization is completed. As a matter of course, the higher the removal rate of the polishing dust, the better, and it is empirically known that even a few tens of polishing dusts in the submicron unit will adversely affect the circuit pattern formation. Incidentally, the above-mentioned polishing residue is generally referred to as “particle”.
The term is also used in the present invention.

Prior to the flattening work by the subsequent polishing, a cleaning work using a cleaning brush made of a material such as PVA (polyvinyl alcohol) was carried out. PVA is widely used as a material for this cleaning brush because it has a proper flexibility and a chemical solution containing water used for cleaning as a solvent (specifically, an alkaline solution such as pure water or ammonia water, or This is because it has been recognized from the material viewpoint that it is difficult to scratch such as scratches due to its affinity with dilute hydrofluoric acid and other acidic solutions). In addition, the PV
A has a negative surface potential (evaluated by the zeta potential, etc.) due to its material, but due to the electric repulsive force generated between the slurry to be cleaned, the chemical solution, and the contaminated particles such as particles. It is also known that wiping and cleaning become easy.

[0007]

However, the above-mentioned P
The following drawbacks have been pointed out for the VA cleaning brush. That is, since the cleaning brush made of PVA has flexibility but is poor in abrasion resistance, the PVA as a material is worn during use and a large amount of fine particles are generated. As a result, the particles such as the slurry are cleaned while the contamination by the particles progresses. Further, due to abrasion, it lacks in durability and the frequency of replacement becomes high, resulting in an increase in use cost. Further, it is empirically known that the generation of the fine particles is irregular and difficult to be quantitatively grasped, and that the generation of the fine particles increases as the usage time increases. Regarding the handling at the time of use, it is general that the cleaning liquid is usually attached to a jig or the like of a polishing device in a swollen state, but the PVA cleaning brush shows high water absorption. The mounting is difficult, and as a result, there is an uneven cleaning depending on the site, that is, uniform cleaning cannot be expected. Further, since the PVA cleaning brush is stored in a state in which it is swollen in a liquid such as water, generation of microorganisms is considered, and in some cases, there is a fear of contamination by the microorganisms. When PVA is used as a material, it is required to be used during drying because it is hard to be shaped because it is hard during drying and swelling, that is, it is hard during drying, and is in a flexible state during swelling and suitable for washing. After being processed into the shape described above, it is generally used by swelling, but in this case, the swelling causes a volume expansion, and therefore a dimensional accuracy is low and a defect that a shape defect is likely to occur is pointed out.

[0008]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the problems inherent in conventional cleaning brushes, and has been proposed as a suitable solution. By using a polyurethane foam with a specified range of chemical mechanical polishing (Che
An object of the present invention is to provide a cleaning brush having physical properties such as hardness, abrasion resistance and tear strength, which can be suitably used for cleaning a manufacturing apparatus after performing mical mechanical polishing (CMP), that is, so-called post-CMP cleaning.

[0009]

In order to overcome the above problems and achieve the intended purpose, the cleaning brush according to the present invention comprises a polyol component and an isocyanate component as main raw materials,
A polyurethane foam obtained by mixing this with various auxiliary materials such as a catalyst and water and processing it into a desired shape, wherein ethylene oxide that exhibits hydrophilicity and reactivity with one of the main polyols of the polyol component is used. A polyether polyol having an internal content of 30 parts by weight or less, a polymer polyol containing a vinyl-based monomer, which is one of the polyol components, an isocyanate component having an isocyanate index of 80 to 150, and an amine. The polyurethane foam obtained by mixing with a non-metallic catalyst such as a catalyst,
The Asker F hardness is set in the range of 50 to 95, the weight change rate showing wear resistance according to JIS K 7204 is set to 3.5% or less, and it is suitable for cleaning particles such as semiconductor materials. It is characterized by having a fine and uniform three-dimensional network structure.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a cleaning brush according to a preferred embodiment of the present invention will be described below with reference to a preferred embodiment. The inventor of the present application has heretofore required a material having a predetermined shape as a material of a cleaning brush used for so-called post-CMP cleaning, which removes particles generated by the planarization when the surface of a semiconductor wafer or the like is planarized by CMP. By using a polyurethane foam that can be molded into, and whose composition values are controlled, and the physical properties such as hardness and abrasion resistance can be set in a required range, the object to be cleaned by the cleaning, For example, without causing damage such as a scratch that is directly connected to a circuit defect or the like, and eliminating a harmful effect such that the constituents of the cleaning brush are scraped by friction during the cleaning, and conversely contaminate the object to be cleaned. It was discovered that a suitable cleaning brush to be obtained can be obtained. It was also found that the particle scraping performance can be improved by containing a polymer polyol containing a monomer. In the field of the present invention, not only the so-called brush shape,
What is commonly called a pad shape is also commonly expressed as the term “brush”, and therefore this term is used in the description of the present invention.

The cleaning brush 10 according to the present embodiment is used by being attached to a predetermined cleaning device, and as shown in FIG. 1, the cleaning brush 10 contacts an object to be cleaned such as a semiconductor wafer after polishing to be cleaned. A circular brush surface 10 that contacts and cleans
a is formed. The shape of the cleaning brush 10 is attached to a device used for cleaning after so-called CMP,
Further, the shape is not limited to the shape of this embodiment as long as the shape of the object to be cleaned can be suitably washed.

The material of the cleaning brush 10 is 3
The three-dimensional network structure allows a predetermined water permeability (breathability) that allows a cleaning liquid or the like to easily pass therethrough.
Particles to be cleaned at the time of so-called post-CMP cleaning such as RCA cleaning after P polishing can be efficiently removed, and electrically, here, by a zeta potential so as not to take the particles during removal into the brush 10. Polyurethane materials known to be capable of exhibiting resilience properties are suitable.

The physical properties required for the cleaning brush 10 can be expressed by tear strength as an index of hardness, abrasion resistance and mechanical strength. It is desired that the hardness is such that a semiconductor wafer or the like to be cleaned is not scratched during cleaning, and abrasion resistance is such that the constituents of the cleaning brush 10 itself are peeled off due to friction during the cleaning. It is necessary to prevent the pollution degree from increasing. The above-mentioned two physical properties are contradictory to each other, and generally, there is a relation that the higher the hardness, the higher the abrasion resistance, and the lower the hardness, the lower the abrasion resistance. For this reason, it is necessary to manufacture the cleaning brush 10 as a composition or the like that can balance these two physical properties, and it is also possible to improve only the abrasion resistance without increasing the hardness by improving the tear strength.

In the present invention, the hardness is represented by Asker F hardness and its range is 50 to 95, preferably 55 to 95.
Set to 85. If the hardness is less than 50, it becomes difficult to secure sufficient wear resistance as described above, and if it exceeds 95, there is a fear of scratching the object to be cleaned. This hardness is largely determined by the mixing amount of the polymer polyol, the type and content of the vinyl monomer to be mixed, the isocyanate index and the type thereof.

The wear resistance is represented by a weight change rate indicated by a method according to JIS K7204. Further, the weight change rate is P, which is a material that has been preferably used so far.
VA or less, that is, 3.5% or less (details will be described later (Experimental example:
It must be abrasion resistant [0046])). Factors that achieve this rate of weight change include the amount of polymer polyol mixed, the type and content of vinyl monomers that are mixed, the isocyanate index and the type thereof. In addition to this, it is necessary to pay attention because it is closely related to the hardness and the density described above.

The tear strength is one index that can improve the wear resistance without increasing the hardness as described above.
It is desired that the value measured by the method according to IS K 6400 (general analysis standard for flexible foam) is 15 N / cm or more, preferably 20 N / cm. If this value is less than 15 N / cm, it becomes difficult to maintain the above-mentioned wear resistance at a high level. Factors that achieve this tear strength include the mixing amount of the polymer polyol, the type and content of the vinyl-based monomer to be mixed, the isocyanate index and the type thereof.
In addition to the wear resistance, the hardness and the density are closely related to each other.

The polyurethane foam constituting the cleaning brush 10 has one of the functions required by the brush 10.
That is, it is preferable to have a three-dimensional network structure in order to ensure sufficient dischargeability of the particles to be cleaned by the cleaning liquid. A three-dimensional network structure, that is, a structure in which the cell skeleton of the foam is destroyed to leave only the resin skeleton of the foam is specifically manufactured by the pressing roller or the like after the foam is manufactured. Mechanically compresses, thereby destroying the cell membrane, so-called physical treatment, mixing combustible substances such as natural gas with oxygen within the explosion limit, igniting and exploding, and destroying the cell membrane by the impact. It is obtained by a method such as melting treatment.

In order to obtain a polyurethane foam having a suitable three-dimensional network structure by the above-mentioned physical treatment or melting treatment, it is necessary to make the cell membrane formed after foaming the foam as thin as possible. There is. This is generally done by adding a foam stabilizer for reducing the interfacial tension to the raw material blending system of the polyurethane foam, but in the present invention, the foam stabilizer is used for the reason described below ([0041]). The use of is avoided as much as possible.

The amount of water mixed as a foaming agent is usually (2 to 3) in order to make the cell diameter of the resulting foam fine and to increase the density to improve abrasion resistance. It is set to 1.5 parts by weight or less, which is less than (parts by weight).

Since the cleaning brush 10 thus obtained has no cell film due to the above-mentioned treatment, it is easily peeled off by friction during cleaning so that it is not contaminated by "cell film" which may become a contamination source. You don't have to think. Note that the removal of the cell film described here is not essential,
For example, depending on the actual cleaning conditions such as the pressing force of the cleaning brush 10 on the object to be cleaned and the speed of rotational movement for achieving cleaning, the brush 10 with the cell film remaining may be sufficient. You can expect a good cleaning performance.

[0021]

[Example of Manufacturing Apparatus and Manufacturing Method] An example of the manufacturing apparatus and manufacturing method of the cleaning brush 10 will be described below. The cleaning brush 10 is preferably manufactured by a general slab foaming method for manufacturing an ordinary polyurethane foam, but in addition to this, a general manufacturing method according to a conventional technique can be appropriately adopted. Is. Specifically, it is preferably manufactured by the manufacturing mechanism 20 and manufacturing process as shown in FIGS. 2 and 3.

As shown in FIG. 2, the manufacturing mechanism 20 includes a plurality of first raw material tanks 32 for storing a required plurality of types of polyol components, a first mixing head 33 for premixing the respective polyol components, and A premix tank 34 for storing the mixed mixed polyol raw material, a second raw material tank 35 for storing the isocyanate component, a mixing head 36 for mixing the polyol component and the isocyanate component premixed by the first mixing head 33, and slab foaming. The slab foam body 1 having a predetermined thickness, which is composed of the portion 38.
Foaming apparatus 30 for producing No. 4 and the obtained slab foam 1
Processing device 5 that processes 4 into the required cleaning brush 10.
Basically from 0.

In the foaming device 30, each of the first raw material tank 32 and the first mixing head 33, the first mixing head 33 and the premixing tank 34, the premixing tank 34 and the mixing head 36, the second raw material tank The mixing head 35 and the mixing head 36 are connected to each other by a supply line. Each of the raw material tanks 32 and 35 has a mixer 32.
a and 35a are provided, and the raw materials stored in the raw material tanks 32 and 35 are agitated under control.

The processing device 50 includes a skiving machine 52 for converting the obtained slab foam 14 having a predetermined thickness into a sheet foam 16 having a thickness substantially equal to the thickness of the cleaning brush 10 to be obtained. And a rotary processing machine 54 for forming the cylindrical foam 18 by hollowing out the sheet foam 16.

The cylindrical foam 18 thus obtained
Is a cleaning brush 10 which is a final product to be obtained by an operator or the like in another step not shown. Further, the slab foam 14 obtained by the foaming device 30 may be processed by the processing device 50 after subjecting the slab foam 14 to a required cell breaking process to remove the cell membrane in advance.

In the present embodiment, the cleaning brush 10 is obtained by cutting the slab foam 14 at one end and then cutting the slab foam 14 out. Using a press molding die or an injection molding die having a cavity that matches the outer contour shape of the cleaning brush 10 to be controlled, and directly performing the cleaning without performing the above-mentioned processing by press molding or injection molding. The brush 10 may be manufactured. Further, in this case, since a so-called skin layer is formed on the surface of the obtained cleaning brush 10, it is essential to remove the skin layer.

In the process of manufacturing the cleaning brush 10 made of polyurethane foam by the manufacturing mechanism 20, basically, a premixing process S1 of premixing a plurality of kinds of polyol raw materials, a premixed polyol raw material, Mixing step S2 of mixing an isocyanate raw material and other auxiliary raw materials such as a catalyst, foaming step S3 of foaming the obtained mixed raw material by the slab foaming section 38, and the obtained slab foam 1
4 includes a processing step S4 for forming the cleaning brush 10 into the shape of the cleaning brush 10 by the processing device 50, and a final step S5 for performing post-processing and predetermined inspection (see FIG. 3).

As the main polyol which is one of the above-mentioned polyol components, a known polyether polyol which is resistant to such an environment is preferably used in consideration of use in the presence of a cleaning liquid or the like. The polyether polyol is
It is obtained by addition-polymerizing polyethylene oxide or / and propylene oxide, which is an epoxide, to a bifunctional to octafunctional compound as an initiator. Examples of the initiator include the following. That is, as the bifunctional compound, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, as the trifunctional compound, glycerin, trimethylolpropane, 1,2,6-hexanetriol and triethanolamine, and as the tetrafunctional compound, pentaerythritol, tolylenediene. Examples include amine and diphenylmethanediamine, and the like, and pentafunctional compounds such as diethylenetriamine, hexafunctional compounds such as sorbitol and mannitol, and octafunctional compounds such as sucrose. In particular, the number average molecular weight is 1,000 to 10,000, more preferably a trifunctional compound and the number average molecular weight is 4,000 to
It has been empirically known that about 10,000 can be preferably used. Depending on the environment in which it is used frequently, such as when it is replaced in a short period of time, the influence of hydrolysis can be ignored, and thus polyester polyol may be used instead of the polyether polyol.

The addition structure of the ethylene oxide and propylene oxide to be added is not particularly limited, but it is one which imparts reactivity with isocyanate and molecular hydrophobicity to the resulting polyol. It is necessary to pay attention to. That is, when the addition amount of the ethylene oxide is too large, the reactivity with isocyanate becomes high and the polyurethane foam can be efficiently obtained in a short time, while the hydrophilicity increases. The opposite phenomenon occurs with propylene oxide. Regarding the hydrophilicity, if the degree is too high, the resulting polyurethane foam will swell when it comes into contact with water, the tear strength and the like of the skeleton will be greatly deteriorated, and as a result, the abrasion resistance will be reduced. The problem is inherent. Further, when the hydrophilicity is low, that is, the hydrophobicity is high, so-called drainage is good, and when used as a cleaning brush, it is possible to reduce the fear that particles and the like remain in the cleaning brush, which is preferable.

In view of these points, the addition ratio of ethylene oxide is preferably 30 parts by weight or less, and more preferably 15 parts by weight or less in terms of internal ratio. Within such an addition ratio range, the hydrophilicity exhibited by the cleaning brush made of the obtained polyurethane foam does not affect the cleaning property of the brush, and the reaction with the isocyanate does not occur. The property can be sufficiently secured.

The polymer polyol required as one of the above-mentioned polyol components is a polyol obtained by graft-polymerizing a vinyl-based monomer such as a polyvinyl monomer to the above-mentioned polyether polyol. Refers to the morphology. As the vinyl-based monomer, acrylonitrile, styrene, methyl methacrylate, or the like is used alone or in combination. This vinyl monomer is used for the cleaning brush 10
In the above, the so-called scraping effect of efficiently removing particles from the object to be cleaned is exhibited, and it plays a great role for the cleaning brush 10 according to the present invention.

Further, when cleaning the object to be cleaned, the vinyl-based monomer has the beneficial effect of scraping performance, as described above, while the vinyl-based monomer is used for cleaning the cleaning object by contact by scraping or the like. It is conceivable that the object to be cleaned may fall off from the brush 10 and, as a result, the object to be cleaned may be contaminated like particles to be removed. However, in the case of the cleaning brush according to the present invention, the vinyl-based monomer is contained and held as one of the compositions in the polyether polyol serving as the matrix in the form of the polymer polyol, and thus the above-mentioned drop-off becomes a problem. There is no such thing.

The content of the vinyl monomer is
Considering that the above-mentioned scraping performance and reactivity (when the amount is too much, the reaction between the mixed polyol component and the isocyanate component becomes excessive) is taken into consideration, the internal ratio is preferably 50 parts by weight or less. Has been confirmed empirically.
A mixture of acrylonitrile and styrene is generally used as the vinyl-based monomer.

Further, the above-mentioned polyether polyol, which becomes the matrix of the polymer polyol, is mixed with the above-mentioned main polyol, that is, the polyether polyol, to prepare a mixed polyol raw material, and therefore it is necessary to consider mutual compatibility. The compatibility is determined by the content of epoxide added to the polymerization initiator. Specifically, the addition amount of ethylene oxide, which is the epoxide, is 2 in terms of internal ratio.
It is suitable when the amount is 0 parts by weight or less, preferably 15 parts by weight or less.

Since the polymer polyol is generally mixed for the purpose of increasing the density and strength of the polyurethane foam to be obtained, it is represented by tear strength with respect to the cleaning brush 10 as the final product. It is expected that the mechanical strength and wear resistance will be improved. However, on the other hand, with the improvement of mechanical strength and wear resistance described above,
The hardness of the resulting polyurethane foam will also be high,
Care must be taken because there is a fear that the object to be cleaned may be scratched when used as the cleaning brush 10. Considering this point, the mixing amount of the polymer polyol with respect to 100 parts by weight of the polyether polyol which is the main polyol is set in the range of 10 to 60 parts by weight. If this mixing amount is less than 10 parts by weight, abrasion resistance and tear strength will not be sufficient, and a scraping effect cannot be expected. Again 6
If it exceeds 0 parts by weight, the hardness becomes too high.

When a substance having a high hardness such as acrylonitrile is used as the vinyl-based monomer, there is a fear that the same problem as described above may occur. Therefore, it is necessary to take measures such as reducing the use ratio. Further, this vinyl-based monomer has been confirmed to have an effect of physically removing the cell film formed inside the skeleton (the monomer destroys the cell film) when the polyurethane foam is obtained.

As the isocyanate component, any of aromatic and aliphatic compounds can be used. In particular,
2,4- or 2,6-toluene diisocyanate and mixtures thereof, monomeric-diphenylmethane diisocyanate (MDI), polymeric-MDI, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, phenylene diisocyanate, xylene diisocyanate , Isophorone diisocyanate, naphthalene diisocyanate, and the like. Further, these modified products and derivatives can also be used. Examples of the modified product include a urethane modified product, an allophanate modified product, a biuret modified product, an isocyanurate modified product, a carbodiimide / uretonimine modified product, and the like.By using the modified product, chemical resistance is improved, that is, RCA cleaning or the like. On the other hand, improvement in wear resistance can be expected. The substances that can be used in the present invention are not limited to the substances described here.

Diphenylmethane diisocyanate (MDI), which is an aromatic isocyanate, is preferred because it imparts great strength, abrasion resistance and durability to the polyurethane foam to be obtained.

Further, the isocyanate component has an isocyanate index in the range of 80 to 150. This is because if the isocyanate index is less than 80, the abrasion resistance is poor, and if it exceeds 150, the hardness is high and there is a fear of scratching the object to be cleaned during cleaning.

The catalyst used as a polymerization initiator in obtaining the polyurethane foam is tin so as not to be contaminated with metal ions or the like when used as the cleaning brush 10 as the final product. Other than metal catalysts such as compounds and lead compounds, water-soluble non-metal catalysts composed of organic substances such as water-soluble amine catalysts are preferably used. Specifically, dimethylcyclohexylamine, triethylamine as a monoamine, pyridine as a cyclic monoamine, tetramethylethylenediamine as methylmorpholine or ethylmorpholine or a diamine, oxydiethylenedimorpholine or ethyleneglycolbis (3-dimethylamino) as an etherdiamine. Propyl) ether, pentamethyl acetylene triamine as triamine, cyclic polyamine 1,
4-diazabicyclo [2,2,2] octane, dimethylpiperazine, methyldimethylaminoethylpiperazine or diazabicycloundecene phenol salt, carboxylate salt or octyl salt and the like can be mentioned. Note that the water-insoluble organic matter may also be used for substances that can be sufficiently removed by pre-cleaning or substances that do not flow out of the brush 10 during cleaning using the brush 10.

Besides, the use of the foam stabilizer is restricted for the same reason as that of the catalyst. That is, generally used foam stabilizers are usually silicon-based, and it is well known that silicon contamination of semiconductor wafers and the like subjected to post-CMP cleaning causes great obstacles to circuit formation and the like. This is because, with respect to other cationic or anionic foam stabilizers, contamination with various ions is considered to be a problem.

Other auxiliary materials such as a plasticizer and / or a coloring material are appropriately used as necessary after considering the contamination of the object to be cleaned when the cleaning brush 10 is used. To be done.

Further, when the polyurethane foam as a material is produced, the larger the expansion ratio, which is one index, the more effectively the hardness is lowered. Therefore, the polyol component and the isocyanate component as the main raw materials should be blended. As a specific matter, when the desired physical properties cannot be achieved as a result, it is possible to change the physical properties for the purpose of adjusting the physical properties. Further, since it has been found that the cell diameter of the polyurethane foam is preferably about 50 to 300 μm, it is possible to select each raw material while keeping it within this range. Encouraged.

[0044]

[Experimental example] Next, a cleaning brush manufactured by the manufacturing mechanism 20 and the manufacturing method described above (see FIG. 1 for the shape (outer diameter of the brush surface is 30 mm)) is manufactured using the following substances,
Each physical property value was measured. The cleaning brush according to the present invention is not limited to this experimental example.

(Raw materials used) Main polyol: Polyether polyol with ethylene oxide addition rate of 10 parts by weight Polymer polyol (hereinafter referred to as POP): Acrylonitrile 25% and styrene 75% as vinyl monomers
A polyether polyol / isocyanate containing 25 parts by weight as an internal ratio and having an ethylene oxide addition rate of 10 parts by weight: trade name MP-102 (MDI); BI.
Product made by P: Catalyst: Product name Polycat77; Product made by Air Products Japan

(Experiment 1) Comparison with a cleaning brush obtained by using PVA as the material. As the material of Example 1, polyurethane foam having a mixing ratio shown in Table 1 was used.
Was used to prepare cleaning brushes each having the above-mentioned required shape, and the hardness, abrasion resistance, tear strength and scraping performance were measured. The measuring method of each physical property value is as follows.

Hardness: According to Asker F hardness meter. -Abrasion resistance: Measured by a method according to JIS K 7204 (Plastics-Abrasion test method based on abrasion theory). Method: Using a taper wear tester, measure the rate of weight change before and after 500 rotations. Rotation condition: 60 rpm, load 250 g, test piece (mm)
100 × 100 × 5 ・ Tear strength: Measured by a method according to JIS K 6400. Scraping performance: Evaluated by the removal rate of PSL (polystyrene latex). Method: Uniformly apply a predetermined PSL (trade name: STADEX; made by Japan Synthetic Rubber) to the evaluation wafer, and bak
e (baking) temperature 155 ° C., baking time 80 sec,
After baking under the condition of cooling for 60 sec, the cleaning brush is pressed against the evaluation wafer with a predetermined brush pressure, the removal amount of PSL applied under the condition of one-way radius one time is measured, and the removal rate is calculated from there. did.

[0048]

[Table 1]

(Results of Experiment 1) The results obtained are also shown in FIG. From this result, as compared with PVA which has been preferably used as a material for conventional cleaning brushes, it is equivalent in hardness and tear strength, less than half in terms of abrasion resistance, and remarkable in scratching performance. The effect was confirmed.

(Experiment 2) Relationship between Mixing Amount of Each Composition and Hardness and Abrasion Resistance Example 1 (Experiment 1 mixing amount: 30 parts by weight of POP,
Based on Isocyanate Index 103), P
The hardness and the scraping performance were measured for Comparative Example 2, Comparative Example 3 and Comparative Example 4 (compositions of each Comparative Example are shown in Table 2) in which the amount of OP mixed or the isocyanate index was changed.

[0051]

[Table 2]

(Results of Experiment 2) The results obtained are also shown in Table 2 above. From these results, when the amount of POP mixed and the isocyanate index are out of the ranges described in the present invention, the scraping performance becomes comparable to that of the conventional PVA, or high scraping performance is exhibited, but the hardness becomes too high. Was confirmed to occur.

(Experiment 3) The content of the vinyl monomer,
Relationship with Scraping Performance Example 1 (Vinyl monomer content 3
Based on 0 part by weight), the scraping performance was measured for Comparative Example 2 and Comparative Example 5 (compositions of each Comparative Example are shown in Table 3) according to Experiment 2 in which the vinyl-based monomer content was changed.

[0054]

[Table 3]

(Results of Experiment 3) The results obtained are also shown in FIG. From these results, it was confirmed that the scratching performance becomes good when the content exceeds the range of the present invention.

[0056]

As described above, according to the cleaning brush of the present invention, by using the polyurethane foam having the hardness and the abrasion resistance within the predetermined range as the material, the cleaning object can be cleaned. It is possible to manufacture a cleaning brush having physical properties such as hardness, abrasion resistance, and tear strength, which can exhibit good cleaning properties for a barrel semiconductor wafer and the like. Regarding the physical properties such as the water permeability (air permeability) and the zeta potential of the cleaning liquid, PV which is a material that has been preferably used so far.
It is equivalent to A, can be stored in a dry state, and there is no need to consider the reproduction of microorganisms.

[Brief description of drawings]

FIG. 1 is a perspective view showing a cleaning brush according to a preferred embodiment of the present invention.

FIG. 2 is a schematic view showing an example of a manufacturing apparatus that preferably manufactures the cleaning brush according to the embodiment.

FIG. 3 is a process drawing showing the manufacturing process of the cleaning brush according to the embodiment.

Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08G 101: 00) (72) Inventor Ryo Muramatsu 380-5 Horiyamashita, Hadano City, Kanagawa Prefecture Inoac Technical Research Institute (72) ) Inventor Yasuyuki Kumagai 380-5, Horiyamashita, Hadano, Kanagawa Pref., Inoac Technical Research Institute Co., Ltd. (72) Inventor Yosuke Nakano, 3-1-136, Imaikecho, Anjo City, Aichi Pref. Reference) 3B116 AA02 AA03 BA08 4J034 BA07 DG03 DG04 DG14 DG22 DG23 HA07 HC12 HC64 HC71 KD12 NA03 QB16 QB19 RA19

Claims (7)

[Claims] 1. A polyurethane foam obtained by using a polyol component and an isocyanate component as main raw materials, mixing them with various auxiliary raw materials such as a catalyst, and water, and processing the mixture into a desired shape. In the main polyol, a polyether polyol in which the addition ratio of ethylene oxide expressing hydrophilicity and reactivity is 30 parts by weight or less at an internal ratio, and a polymer polyol containing a vinyl monomer as one of the polyol components, It is produced by mixing an isocyanate component having an isocyanate index in the range of 80 to 150 and a nonmetallic catalyst such as an amine catalyst, and the obtained polyurethane foam has an Asker F hardness of 50 to 95. Is set to the range of JIS K
According to 7204, the rate of weight change showing wear resistance is 3.5
%, And a cleaning brush having a fine and uniform three-dimensional network structure suitable for cleaning particles such as semiconductor materials. 2. The cleaning brush according to claim 1, wherein the mixing amount of the polymer polyol is set in the range of 10 to 60 parts by weight with respect to 100 parts by weight of the polyether polyol which is the main polyol. 3. The vinyl monomer content of the polymer polyol is 50 parts by weight or less at an internal ratio.
Alternatively, the cleaning brush described in 2. 4. The cleaning brush according to claim 1, wherein the addition ratio of ethylene oxide in the polymer polyol is set to 20 parts by weight or less, preferably 15 parts by weight or less in terms of an internal ratio. 5. The cleaning brush according to claim 1, wherein the tear strength of the polyurethane foam is set to 15 N / cm or more, preferably 20 N / cm or more. 6. The cleaning brush according to claim 1, wherein diphenylmethane diisocyanate (MDI) is used as the isocyanate component. 7. The cleaning brush according to claim 1, wherein the polyurethane foam is subjected to cell film removal by physical treatment, melting treatment, or the like.