JP2019121795A - Manufacturing method of silicon wafer - Google Patents

Abstract

To provide a manufacturing method of a silicon wafer capable of reducing residue on the wafer surface.SOLUTION: A manufacturing method of a silicon wafer according to an embodiment includes (1) a step of polishing the surface of the silicon wafer to be polished by using a polishing composition A, (2) a step of immersing the silicon wafer obtained in the step (1) in a liquid composition B including a nonionic surfactant b1, and (3) a step of cleaning the silicon wafer obtained in the step (2) by using a cleaning composition C. However, the surface tension of the nonionic surfactant b1 is 43 N/m or less, and the polishing composition A and the cleaning composition C are substantially free of the nonionic surfactant b1.SELECTED DRAWING: None

Description

  The present disclosure relates to a silicon wafer manufacturing method.

  2. Description of the Related Art In recent years, design rules for semiconductor devices have been miniaturized from the increasing demand for higher recording capacity of semiconductor memories. For this reason, the depth of focus becomes shallow in the photolithography performed in the manufacturing process of semiconductor devices, and the demand for reduction of surface defects (LPD: Light point defects) and surface roughness (haze) of silicon wafers (bare wafers) becomes increasingly strict. It has become.

  In order to improve the quality of silicon wafers, polishing of silicon wafers is performed in multiple stages. If particles derived from polishing debris or abrasive grains remain on the surface of the silicon wafer after polishing, it causes surface defects. Usually, a silicon wafer after polishing is carried to a cleaning process to remove particles remaining on the wafer surface, but is stored in water until it is carried to the cleaning process. This is because when the silicon wafer is stored in the atmosphere, particles stick to the wafer surface, which makes it difficult to remove in the cleaning process.

As a method of removing particles remaining on the wafer surface after polishing, for example, Patent Document 1 discloses a method of cleaning using a cleaning agent containing an anionic surfactant, an organic solvent and an alkali component. .
Patent Document 2 discloses a method of storing a silicon wafer after polishing in storage water having a Cu concentration of 0.01 ppb or less.
Patent Document 3 discloses a method of hydrophilizing a mirror surface of a silicon wafer which has been subjected to rinse processing after mirror polishing.
Patent Document 4 discloses a method of storing a silicon wafer after polishing in storage water having a liquid temperature of 0 to 18 ° C.

JP, 2009-206481, A Japanese Patent Application Laid-Open No. 11-191543 JP 2007-235036 A WO 2002/075798

  In recent years, particles remaining on the wafer surface are becoming finer, and it is easier to adhere to the wafer surface more than ever, and a method for more effectively removing the particles remaining on the wafer surface is required.

  Thus, the present disclosure provides, in one aspect, a method of manufacturing a silicon wafer that can reduce residue on the wafer surface.

The present disclosure relates, in one aspect, to a method for producing a silicon wafer, which includes the following steps (1), (2) and (3).
(1) A step of polishing the surface of the silicon wafer to be polished using the polishing composition A.
(2) A step of immersing the silicon wafer obtained in the step (1) in a liquid composition B containing a nonionic surfactant b1.
(3) A step of cleaning the silicon wafer obtained in the step (2) using the cleaning composition C.
However, the surface tension of the nonionic surfactant b1 is 43 N / m or less,
The polishing composition A and the cleaning composition C are substantially free of the nonionic surfactant b1.

  The present disclosure relates, in another aspect, to a liquid composition for storing a silicon wafer, which comprises nonionic surfactant b1 having a surface tension of 43 N / m or less at a critical micelle concentration or more.

  According to the present disclosure, in one aspect, it is possible to provide a method of manufacturing a silicon wafer capable of reducing the residue on the wafer surface.

  The present disclosure is based on the finding that, by immersing a silicon wafer after polishing in a liquid composition containing a predetermined nonionic surfactant, it is possible to reduce the residue on the wafer surface which causes the generation of surface defects. .

That is, the present disclosure relates, in one aspect, to a silicon wafer manufacturing method (hereinafter, also referred to as “the manufacturing method of the present disclosure”) including the following steps (1), (2) and (3).
(1) A step of polishing the surface of the silicon wafer to be polished using the polishing composition A.
(2) A step of immersing the silicon wafer obtained in the step (1) in a liquid composition B containing a nonionic surfactant b1.
(3) A step of cleaning the silicon wafer obtained in the step (2) using the cleaning composition C.
However, the surface tension of the nonionic surfactant b1 is 43 N / m or less,
The polishing composition A and the cleaning composition C are substantially free of the nonionic surfactant b1.

The details of the mechanism of the effects of the present disclosure are not clear, but are presumed as follows.
Generally, in the production of silicon wafers, since the polishing machine and the washing machine are not integrated, it is necessary to transport them from the polishing machine to the washing machine. In order to efficiently remove particles attached to the wafer surface by the cleaning machine, reduce the amount of residue adhering to the wafer surface before cleaning, or make the residue easily peel off the wafer surface It is conceivable.
Therefore, in the present disclosure, the step of immersing the polished silicon wafer in the liquid composition B including the predetermined nonionic surfactant b1 is provided between the polishing step and the cleaning step. As a result, it is considered that the hydrophobic group of the predetermined nonionic surfactant b1 in the liquid composition B is adsorbed on the surface of the silicon wafer, and particles adhering to the surface of the silicon wafer are easily peeled off. Then, it is considered that re-adhesion of the abrasive particle to the wafer surface can be suppressed by the repulsive force of the hydrophilic group of the predetermined nonionic surfactant b1. In this way, particles that cause surface defects are considered to be removed from the wafer surface.
However, the present disclosure may not be interpreted as being limited to these mechanisms.

  Hereinafter, the details of the steps (1) to (3) will be described.

[Step (1): Polishing Step]
Step (1) in the manufacturing method of the present disclosure is a step (polishing step) of polishing a silicon wafer to be polished using the polishing composition A. Step (1) is preferably the final polishing step and / or the finish polishing step in one or more embodiments.

[Abrasive liquid composition A]
The polishing composition A used in the step (1) is, in one or more embodiments, a polishing composition substantially free of the nonionic surfactant b1. Here, that the polishing composition A does not substantially contain the component b1 means that the content of the component b1 in the polishing composition A is less than 0.008 mass%, preferably substantially 0 mass. It says that it is%. As the polishing composition A, in one or more embodiments, abrasive grains (hereinafter also referred to as “component a1”), water-soluble polymers other than the nonionic surfactant b1 (hereinafter also referred to as “component a2”) And aqueous media.

<Abrasive grains (component a1)>
Examples of the abrasive grains (component a1) that can be contained in the polishing composition A of the present disclosure include silica particles, cerium oxide (hereinafter, also referred to as "ceria") particles, and the like. From the point of view, silica particles are preferred. Examples of the silica particles include colloidal silica, fumed silica, pulverized silica, silica having a surface modified with them, and the like, and from the viewpoint of reducing the residue on the wafer surface, colloidal silica is preferable. Component a1 may be used alone or in combination of two or more.

  From the viewpoint of operability, the use form of the component a1 is preferably in the form of slurry. When the component a1 contained in the polishing composition A of the present disclosure is colloidal silica, from the viewpoint of preventing the contamination of the silicon wafer by alkali metals, alkaline earth metals, etc., the colloidal silica is a hydrolyzate of alkoxysilane. It is preferable that it is obtained. The silica particles obtained from the hydrolyzate of alkoxysilane can be produced, for example, by a conventionally known method.

The average primary particle diameter of the component a1 is preferably 10 nm or more, more preferably 15 nm or more, still more preferably 20 nm or more, from the viewpoint of securing the polishing rate, and 40 nm or less from the viewpoint of securing the polishing rate and haze reduction. Preferably, 35 nm or less is more preferable, and 30 nm or less is more preferable. In particular, when colloidal silica is used as the component a1, the average primary particle diameter of the component a1 is preferably 10 nm or more, more preferably 15 nm or more, still more preferably 20 nm or more, from the viewpoint of securing the polishing rate. From the viewpoint, 40 nm or less is preferable, 35 nm or less is more preferable, and 30 nm or less is more preferable.
Furthermore, the average primary particle diameter of the component a1 is preferably 10 nm or more and 40 nm or less, more preferably 20 nm or more and 35 nm or less, and still more preferably 20 nm or more and 30 nm or less from the viewpoint of securing the polishing rate and reducing the haze.
In the present disclosure, the average primary particle size of the component a1 can be calculated using the specific surface area S (m ² / g) calculated by the nitrogen adsorption (BET) method.

  The average secondary particle diameter of the component a1 is preferably 10 nm or more and 250 nm or less from the viewpoint of securing the polishing rate and reducing the residue on the wafer surface. When the component a1 is a silica particle, the average secondary particle diameter of the component a1 is preferably 20 nm to 80 nm, more preferably 30 nm to 75 nm, and still more preferably 40 nm to 70 nm. When the component a1 is a ceria particle, the average secondary particle diameter of the component a1 is preferably 10 nm or more and 250 nm or less, more preferably 13 nm or more and 200 nm or less, and still more preferably 15 nm or more and 170 nm or less. In the present disclosure, the average secondary particle size is a value measured by a dynamic light scattering (DLS) method, and can be measured, for example, using the device described in the examples.

  From the viewpoint of securing the polishing rate, the content of the component a1 in the polishing composition A of the present disclosure is preferably 0.04% by mass or more, more preferably 0.09% by mass or more, and 0.13% by mass or more. Furthermore, from the viewpoint of reducing residue on the wafer surface, 0.5 mass% or less is preferable, 0.4 mass% or less is more preferable, and 0.3 mass% or less is still more preferable. Furthermore, the content of the component a1 in the polishing composition A is preferably 0.04% by mass or more and 0.5% by mass or less, from the viewpoint of securing the polishing rate and reducing the residue on the wafer surface, and 0.09% % Or more and 0.4 mass% or less are more preferable, and 0.13 mass% or more and 0.3 mass% or less are more preferable. When the component a1 consists of 2 or more types of abrasive grains, content of the component a1 says those total content.

<Water-soluble polymer (component a2)>
The water-soluble polymer (component a2) that may be contained in the polishing composition A of the present disclosure is a water-soluble polymer other than the nonionic surfactant b1. In the present disclosure, “water-soluble” means having a solubility of 0.5 g / 100 mL or more, preferably 2 g / 100 mL or more in water (20 ° C.). The component a2 may be used alone or in combination of two or more.

  Examples of component a2 include cellulose derivatives, polyvinyl alcohol polymers, polyvinyl phosphorus derivatives, polyvinyl alkyl ether derivatives, polyglycerin derivatives, water-soluble polymers having ethylene oxide groups, water-soluble polymers having amide groups, etc. .

  Examples of the cellulose derivative of the component a2 include carboxymethyl cellulose, hydroxyethyl cellulose (HEC), hydroxyethyl methyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl ethyl cellulose, carboxymethyl ethyl cellulose and the like.

  Examples of the polyvinyl alcohol-based polymer of the component a2 include polyvinyl alcohol (PVA), alkylene oxide modified PVA, cation modified PVA, anion modified PVA, alkyl modified PVA, hydroxyalkyl modified PVA and the like.

  Examples of polyvinylphosphorus derivatives of component a2 include polydimethylvinyl phosphonate, polydiethyl vinyl phosphonate, polydiisopropyl phosphonate, poly 1- (dimethoxyphosphinyl) -1-methylethene, 1- (dimethoxyphosphinyl) 1-1 Phenyl ethene, poly 1- (dimethoxy phosphinyl) -2- phenyl ethene, poly dimethyl-p-vinyl benzyl phosphonate, poly dimethyl-p- vinyl benzyl phosphonate, poly diisopropyl-p- vinyl benzyl phosphonate , Polydiphenyl vinyl phosphonate, poly 2- (dimethoxyphosphinyl) -1-octene, polyvinyl phosphoric acid and the like.

  Examples of the polyvinyl alkyl ether derivative of the component a2 include polyvinyl methyl ether, polyvinyl ethyl ether and the like.

  Examples of the polyglycerin derivative of the component a2 include polyglycerin alkyl ether, polyglycerin alkenyl ether, polyglycerin phenyl ether, polyglycerin alkyl phenyl ether, polyglycerin alkyl ester, polyglycerin alkenyl ester, polyglycerin phenyl ester, polyglycerin alkyl Phenyl ester etc. are mentioned.

  Examples of the water-soluble polymer having an ethylene oxide group of component a2 include homopolymers of monomethoxypolyethylene glycol monomethacrylate (PEGMA), copolymers of methacrylic acid and PEGMA, and pluronic polymers (EO / PO block polymers) Etc.).

  Examples of the water-soluble polymer having an amide group of component a2 include polyacrylamide, polymethacrylamide, polymethylacrylamide, polydiethylacrylamide, polyN-isopropylacrylamide, polyN-hydroxyethylacrylamide, polyN-hydroxymethylacrylamide And poly (t-butyl acrylamide), poly (n-butyl acrylamido) polyvinyl pyrrolidone, polyoxazoline, polyacryloyl morpholine and the like.

  From the viewpoint of securing the polishing rate, the weight average molecular weight of the component a2 is preferably 0.1000 or more, more preferably 10,000 or more, further preferably 50,000 or more, still more preferably 200,000 or more, and aggregation of silica particles. From the viewpoint of suppression, 1.5 million or less is preferable, 1.1 million or less is more preferable, 900,000 or less is more preferable, and 300,000 or less is more preferable. The weight-average molecular weight of the component a2 is preferably from 10,000 to 1,500,000, more preferably from 10,000 to 1,100,000, further preferably from 50,000 to 900,000, from the viewpoint of securing the polishing rate and suppressing aggregation of silica particles. Preferably, 200,000 or more and 300,000 or less are more preferable.

  In the present disclosure, the weight average molecular weight can be measured by gel permeation chromatography (GPC) using liquid chromatography (L-6000 high performance liquid chromatography manufactured by Hitachi Ltd.).

  From the viewpoint of securing the polishing rate, the content of the component a2 in the polishing composition A of the present disclosure is preferably 0.0005% by mass or more, preferably 0.001% by mass or more, and more preferably 0.005% by mass or more. 0.01% by mass or more is more preferable, and from the same viewpoint, 1% by mass or less is preferable, 0.5% by mass or less is more preferable, 0.1% by mass or less is more preferable, and 0.05% by mass % Or less is even more preferable. From the same viewpoint, the content of the component a2 in the polishing composition A is preferably 0.0005% by mass or more and 1% by mass or less, and preferably 0.001% by mass or more and 0.5% by mass or less, and 0.005 The mass% or more and the 0.1 mass% or less are more preferable, and the 0.01 mass% or more and the 0.05 mass% or less are more preferable. When the component a2 is composed of two or more water-soluble polymers, the content of the component a2 refers to the total content of them.

<Water medium>
Examples of the aqueous medium that may be contained in the polishing composition A of the present disclosure include water such as ion exchanged water and ultrapure water, or a mixed medium of water and a solvent, and the above solvent includes water and Solvents which can be mixed (eg, alcohols such as ethanol) are preferred. The content of the aqueous medium in the polishing composition A of the present disclosure can be the balance excluding the component a1, the component a2, and the optional components described later.

[Other ingredients]
The polishing liquid composition A of the present disclosure is further selected from pH adjusters, basic compounds, preservatives, alcohols, chelating agents, and surfactants other than the component b1 insofar as the effects of the present disclosure are not hindered. At least one other ingredient may be included. The other components are preferably contained in the polishing composition as long as the effects of the present disclosure are not impaired, and the content of the other components in the polishing composition A is 0% by mass or more. Preferably, 0 mass% or more is more preferable, 0.1 mass% or more is further preferable, and 10 mass% or less is preferable, and 5 mass% or less is more preferable.

  As a pH adjuster, an acidic compound and an alkali compound are mentioned, for example. Examples of the acidic compound include inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid and phosphoric acid; and organic acids such as acetic acid, oxalic acid, succinic acid, glycolic acid, malic acid, citric acid and benzoic acid; There are more species. Examples of the alkali compound include at least one selected from inorganic alkali compounds such as ammonia and potassium hydroxide; and organic alkali compounds such as alkylamine and alkanolamine.

  The polishing composition A of the present disclosure can be produced, for example, by blending the component a1, the component a2 and the aqueous medium, and optionally the other components described above by a known method. In the present disclosure, "blending" includes mixing the component a1, the component a2, the aqueous medium, and the other components described above as needed simultaneously or sequentially. The order of mixing is not particularly limited. The compounding can be performed using, for example, a mixer such as a homomixer, a homogenizer, an ultrasonic disperser, and a wet ball mill. In the present disclosure, the compounding amount of each component in the method of manufacturing the polishing composition A can be the same as the content of each component in the above-described polishing composition A of the present disclosure.

  In the present disclosure, “content of each component in the polishing composition A” is the content of each of the components when using the polishing composition A, that is, when starting to use the polishing composition A for polishing. We say content.

  The pH at 25 ° C. of the polishing composition A of the present disclosure is preferably 9 or more, more preferably 9.5 or more, still more preferably 10 or more, and 12 or less from the same viewpoint from the viewpoint of securing the polishing rate. Is preferable, 11.5 or less is more preferable, and 11 or less is still more preferable. From the same viewpoint, the pH at 25 ° C. of the polishing composition A is preferably 9 or more, 12 or less, more preferably 9.5 or more and 11.5 or less, and still more preferably 10 or more and 11 or less. The pH can be adjusted by appropriately adding a pH adjustor described later. Here, the pH at 25 ° C. can be measured using a pH meter (Toa Denpa Kogyo Co., Ltd., HM-30G), and the electrode of the pH meter may be immersed in the polishing composition to obtain a value after 1 minute. it can.

Silicon wafer to be polished
Examples of the silicon wafer to be polished which is a polishing target of the polishing composition A of the present disclosure include a single-crystal 100-face silicon wafer, a 111-face silicon wafer, and a 110-face silicon wafer. The resistivity of the silicon wafer is preferably 0.0001 Ω · cm or more, more preferably 0.001 Ω · cm or more, still more preferably 0.01 Ω · cm or more, from the viewpoint of reducing residue on the wafer surface. Preferably it is 0.1 ohm * cm or more, Preferably it is 100 ohm * cm or less, More preferably, it is 50 ohm * cm or less, More preferably, it is 20 ohm * cm or less. From the same viewpoint, the resistivity of the silicon wafer is preferably 0.0001 Ω · cm or more and 100 Ω · cm or less, more preferably 0.001 Ω · cm or more and 100 Ω · cm or less, still more preferably 0.01 Ω · cm or more and 100 Ω · cm cm or less, more preferably 0.1 Ω · cm or more and 100 Ω · cm or less, further preferably 0.1 Ω · cm or more and 50 Ω · cm or less, and further preferably 0.1 Ω · cm or more and 20 Ω · cm or less.

  Step (1) includes, for example, a lapping (rough polishing) step of planarizing a single crystal silicon wafer obtained by slicing a single crystal silicon ingot into a thin disk, and etching the lapped single crystal silicon wafer And polishing the surface of the single crystal silicon wafer. The polishing composition A of the present disclosure is more preferably used in the finish polishing step from the viewpoint of haze reduction.

  In the step (1), for example, the silicon wafer to be polished can be sandwiched by a surface plate to which a polishing pad is attached, and the silicon wafer to be polished can be polished at a polishing pressure of 3 to 20 kPa.

  The above-mentioned polishing pressure refers to the pressure of the platen which is applied to the surface to be polished of the silicon wafer to be polished at the time of polishing. The polishing pressure is preferably 3 kPa or more, more preferably 4 kPa or more, still more preferably 5 kPa or more, and still more preferably 5.5 kPa or more from the viewpoint of improving the polishing rate and polishing economically. Then, from the viewpoint of improving the surface quality and relaxing the residual stress in the polished silicon wafer, the polishing pressure is preferably 30 kPa or less, more preferably 20 kPa or less, and still more preferably 15 kPa or less. More specifically, 3 kPa or more and 30 kPa or less are preferable, 4 kPa or more and 20 kPa or less are more preferable, 5 kPa or more and 15 kPa or less are still more preferable, and 5.5 kPa or more and 15 kPa or less are still more preferable.

  In the step (1), for example, a silicon wafer to be polished is sandwiched by a platen to which a polishing pad is attached, and the silicon wafer to be polished is polished at a polishing liquid composition A of 15 ° C. to 40 ° C. Can. The temperature of the polishing composition A and the surface temperature of the polishing pad are preferably 15 ° C. or more, more preferably 20 ° C. or more, from the viewpoint of surface defect reduction, and preferably 40 ° C. or less from the viewpoint of haze reduction. C. or less is more preferable, and 30 ° C. or less is more preferable. From the same viewpoint, the temperature of the polishing composition A and the surface temperature of the polishing pad are preferably 15 ° C. or more and 40 ° C. or less, more preferably 20 ° C. or more and 35 ° C. or less, and still more preferably 20 ° C. or more and 30 ° C. or less.

  In step (1), in one or more embodiments, the silicon wafer polished with the polishing composition A is used with the rinse agent composition D substantially free of the nonionic surfactant b1. It can further include the steps of rinsing and hydrophilizing the silicon wafer surface. Here, that the rinse agent composition D does not substantially contain the component b1 means that the content of the component b1 in the rinse agent composition D is less than 0.008 mass%, preferably substantially 0 mass. It says that it is%. As a method of rinsing, for example, a method of rotating a polished silicon wafer while in contact with the rinse agent composition D while pressing on a polishing pad can be mentioned. The rinse agent composition D includes, in one or more embodiments, a rinse agent composition including a water-soluble polymer other than the nonionic surfactant b1. As a water soluble polymer contained in rinse agent composition D, the same thing as ingredient a2 mentioned above can be used, for example.

[Step (2): Immersion Step]
The step (2) is a step of immersing the silicon wafer obtained in the step (1) in the liquid composition B (immersion step). The step (2) may be a step of immersing the silicon wafer obtained in the step (1) in the liquid composition B in one or more embodiments, and storing the silicon wafer until it is carried to the step (3).

[Liquid composition B]
<Nonionic Surfactant (Component b1)>
The liquid composition B used in the step (2) contains the nonionic surfactant b1 (component b1). Component b1 may be used alone or in combination of two or more.

  The surface tension of the component b1 is 43 N / m or less, preferably 42 N / m or less, more preferably 35 N / m or less, and still more preferably 33 N / m or less from the viewpoint of reducing residue on the wafer surface. In the present disclosure, the surface tension of the component b1 can be calculated by the method described in the examples. The surface tension tends to decrease as the concentration of component b1 increases, but becomes constant above the critical micelle concentration (cmc). Therefore, the surface tension of the component b1 can be a value at the critical micelle concentration (cmc) or more in one or more embodiments. The surface tension of the component b1 is preferably in the range described above for cmc or more in one or more embodiments. Therefore, the present disclosure relates, in another embodiment, to a silicon wafer storage liquid composition (hereinafter referred to as “the disclosure of the present disclosure,” containing a non-ionic surfactant b1 having a surface tension of 43 N / m or less at critical micelle concentration or more). The term “liquid composition for storage of silicon wafers” is also referred to. The liquid composition for silicon wafer storage of the present disclosure can be used for storage of a polished silicon wafer in one or more embodiments. The liquid composition for silicon wafer storage of the present disclosure is, in one or more embodiments, a liquid composition for use in step (2) of the production method of the present disclosure.

As a hydrophobic group of component b1, an aliphatic hydrocarbon group and an aromatic hydrocarbon group are mentioned, for example.
The aliphatic hydrocarbon group may be linear or branched, and may be saturated or unsaturated. Examples of the aliphatic hydrocarbon group include at least one selected from a linear alkyl group, a branched alkyl group, and an unsaturated alkyl group, and among these, from the viewpoint of reducing the residue on the wafer surface, straight At least one selected from a chain alkyl group and a branched alkyl group is preferable, and a branched alkyl group is more preferable.
Examples of the aromatic hydrocarbon group include at least one selected from naphthyl group, styrenated phenol group, and benzylated phenol group, and from the viewpoint of reducing the residue on the wafer surface, styrenated phenol group and benzyl group A phenolated phenol group is more preferable, and a styrenated phenol group and a tribenzylated phenol group are more preferable.

  Examples of the hydrophilic group of the component b1 include an oxyalkylene group (AO), and in one embodiment, an ethyleneoxy group (EO) and a propyleneoxy group (PO) from the viewpoint of reducing the residue on the wafer surface. It is preferable that it is a block structure of, and in other embodiment, it is a block structure of EO and PO, and it is preferable that an end is PO. In particular, a triblock structure such as EO-PO-EO or a structure in which the end is PO such as EO-PO is preferable.

The component b1 is selected from, for example, a compound represented by the following formula (I), alkyl (poly) glucoside, alkyl (poly) galactoside, and alkyl (poly) glycerin from the viewpoint of reducing residue on the wafer surface. Preferably, at least one of them is used.
R-O- (AO) n-H (I)

In formula (I), R represents a hydrocarbon group having 8 to 22 carbon atoms. From the viewpoint of reducing residue on the wafer surface, R includes, in one embodiment, a linear or branched aliphatic hydrocarbon group having 8 to 22 carbon atoms, and in another embodiment, 8 carbon atoms. More than 22 or less aromatic hydrocarbon groups are mentioned. When R is an aliphatic hydrocarbon group, the aliphatic hydrocarbon group may be saturated (alkyl group) or unsaturated (alkenyl group).
When R is an aliphatic hydrocarbon group, one embodiment of R includes at least one selected from a linear alkyl group, a branched alkyl group, and an unsaturated alkyl group, and reduces the residue on the wafer surface From the viewpoint of the above, at least one selected from a linear alkyl group and a branched alkyl group is preferable, and a branched alkyl group is more preferable.
When R is an aromatic hydrocarbon group, one embodiment of R includes at least one selected from a naphthyl group, a styrenated phenol group, and a benzylated phenol group, and the residue on the wafer surface can be reduced From the viewpoint, styrenated phenol group and benzylated phenol group are more preferable, and styrenated phenol group and tribenzylated phenol group are more preferable.
The number of carbon atoms of R is preferably 8 or more, more preferably 12 or more, and from the same viewpoint, preferably 22 or less, more preferably 18 or less, from the viewpoint of reducing residue on the wafer surface. More specifically, the carbon number of R is preferably 8 or more and 22 or less, and more preferably 12 or more and 18 or less.

  AO in formula (I) is at least one alkyleneoxy selected from ethyleneoxy group (EO), propyleneoxy group (PO), and a combination of ethyleneoxy group (EO) and propyleneoxy group (PO) Indicates a group. n is an average added mole number of AO and is preferably 2 or more and 20 or less, more preferably 3 or more and 19 or less, and still more preferably 6 or more and 13 or less from the viewpoint of reducing residue on the wafer surface. AO may be only one of EO and PO, or may be a combination of EO and PO. When AO is a combination of EO and PO, the arrangement of EO and PO may be block or random. From the viewpoint of reducing residue on the wafer surface, the proportion of EO groups in (AO) n is preferably 50 mol% or more, more preferably 70 mol% or more, and still more preferably 80 mol% or more.

When AO in the formula (I) is a combination of EO and PO, examples of the compound represented by the formula (I) include a compound represented by the following formula (II), a compound represented by the formula (III) Compounds and the like.
R-O- (EO) q (PO) r (EO) s-H (II)
R-O- (EO) t (PO) u-H (III)
Each of q, r, s, t and u in formulas (II) and (III) represents the average number of moles added. From the viewpoint of reducing residue on the wafer surface, q is preferably 2 or more and 5 or less, more preferably 3 or more and 5 or less, and still more preferably 3 or more and 4 or less. From the same viewpoint, r is preferably 0.1 or more and 4 or less, more preferably 1 or more and 3 or less, and still more preferably 1 or more and 2 or less. From the same viewpoint, s is preferably 2 or more and 5 or less, more preferably 3 or more and 5 or less, and still more preferably 4 or more and 5 or less. From the same viewpoint, t is preferably 5 or more and 20 or less, more preferably 7 or more and 18 or less, and still more preferably 9 or more and 14 or less. From the same viewpoint, u is preferably 1 or more and 16 or less, more preferably 3 or more and 10 or less, and still more preferably 4 or more and 6 or less. However, since the surface tension changes depending on the combination of EO and PO, q, r, s, t and u are not limited to the above ranges, and the surface tension may be 43 N / m or less.

  When component b1 is alkyl (poly) glucoside and alkyl (poly) galactoside, the carbon number of the alkyl group of component b1 is preferably 8 or more, more preferably 10 or more, from the viewpoint of reducing residue on the wafer surface. From the same viewpoint, 16 or less is preferable, and 14 or less is more preferable. More specifically, the carbon number of the alkyl group of the component b1 is preferably 8 or more and 16 or less, and more preferably 10 or more and 14 or less. Specific examples of the component b1 include, for example, polyglucoside having an alkyl group having 10 to 16 carbon atoms, lauryl glucoside, polygalactoside having an alkyl group, lauryl galactoside and the like.

  When component b1 is alkyl (poly) glycerin, the carbon number of the alkyl group of component b1 is preferably 8 or more, more preferably 12 or more, from the viewpoint of reducing residue on the wafer surface, and from the same viewpoint 22 or less is preferable and 18 or less is more preferable. More specifically, 8 or more and 22 or less are preferable, and, as for carbon number of the alkyl group of component b1, 12 or more and 18 or less are more preferable. Specific examples of the component b1 include, for example, lauryl (poly) glycerin having an alkyl group having 12 carbon atoms.

The content of the component b1 in the liquid composition B is preferably a critical micelle concentration (cmc) or more and 0.008% by mass or more, more preferably 0.015% by mass or more from the viewpoint of reducing residue on the wafer surface 0.02% by mass or more is more preferable, 0.04% by mass or more is further preferable, and 3% by mass or less is preferable, 1% by mass or less is more preferable, and 0.5% by mass from the viewpoint of cost and suppression of foaming. % Or less is more preferable, 0.3% by mass or less is further preferable, 0.12% by mass or less is further preferable, 0.08% by mass or less is further preferable, and 0.06% by mass or less is more preferable. From the same viewpoint, the content of the component b1 in the liquid composition B is preferably 0.008% by mass to 3% by mass, more preferably 0.015% by mass to 1% by mass, and 0.02% by mass. The content is more preferably 0.5% by mass or less and still more preferably 0.04% by mass to 0.5% by mass. Furthermore, from the viewpoint of optimizing the reduction of the residue on the wafer surface, it is preferable not to contain in excess of the critical micelle concentration (cmc) or more, and the content of the component b1 in the liquid composition B is 0.02 mass% The content is preferably 0.08 mass% or less, more preferably 0.04 mass% to 0.08 mass%, and still more preferably 0.04 mass% to 0.06 mass%.
When the component b1 is composed of two or more nonionic surfactants, the content of the component b1 refers to the total content of them.

<Water>
Liquid composition B contains water as a medium. Examples of water include ion-exchanged water, distilled water and ultrapure water. The content of water in the liquid composition B can be the balance excluding the component b1 and the optional components described later which are optionally blended.

<Defoamer (Component b2)>
The liquid composition B can further include an antifoaming agent b2 (hereinafter, also referred to as "component b2"). Component b2 is at least one selected from silicone antifoaming agents, alkylene oxide antifoaming agents, alcohol alkoxylate antifoaming antifoaming agents, polypropylene glycol antifoaming agents, and phosphoric acid ester antifoaming agents from the viewpoint of antifoaming properties. Preferably, silicone antifoams are more preferred. The component b2 may be used alone or in combination of two or more.

  The content of the component b2 in the liquid composition B is preferably 10 ppm or more, more preferably 30 ppm or more, still more preferably 50 ppm or more, and still more preferably 100 ppm or more, from the viewpoint of defoaming properties Therefore, 5000 ppm or less is preferable, 3000 ppm or less is more preferable, 2000 ppm or less is more preferable, and 1000 ppm or less is more preferable. More specifically, the content of the component b2 in the liquid composition B is preferably 10 ppm to 5000 ppm, more preferably 30 ppm to 3000 ppm, still more preferably 50 ppm to 2000 ppm, and still more preferably 100 ppm to 1000 ppm. When component b2 consists of 2 or more types of antifoamers, content of component b2 says those total content.

  Liquid composition B may contain other components other than component b1, component b2 and water, as long as the effects of the present disclosure are not hindered. Other components include, for example, pH adjusters and chelating agents. As a pH adjuster, the same thing as the pH adjuster of the polishing liquid composition A mentioned above is mentioned.

  The liquid composition B, in one or more embodiments, from the viewpoint of reduction of residues on the wafer surface, in the Act (PRTR Law) on promoting the improvement of management and the like of the amount of emission of specific chemical substances to the environment, etc. Preferably, it is substantially free of the designated first type designation compound. Here, the content of the first-type designated compound in the liquid composition B is less than 1% by mass, preferably 0.1 mass, as substantially free of the first-type designated compound designated in the PRTR method. % Or less, more preferably substantially 0% by mass.

  The liquid composition B may be substantially free of the basic nitrogen-containing organic compound in one or more embodiments. Here, that the liquid composition B does not substantially contain the nitrogen-containing organic compound means that the content of the nitrogen-containing organic compound in the liquid composition B is less than 0.01% by mass, preferably substantially. It means that it is 0 mass%.

  The liquid composition B in the present disclosure can be produced by blending the component b1, water, and, if desired, the optional components described above by a known method. For example, the liquid composition B can be a mixture of at least the component b1 and water. When the component b1 is a combination of a plurality of types of nonionic surfactants, the component b1 can be obtained by blending each of a plurality of types of nonionic surfactants. Here, "blending" includes mixing the component b1 and water, and optionally, the above-described optional components simultaneously or sequentially. The order of mixing is not particularly limited. The compounding can be performed using, for example, a mixer such as a homomixer, a homogenizer, an ultrasonic disperser, and a wet ball mill. In the present disclosure, the compounding amount of each component in the method for producing the liquid composition B can be the same as the content of each component in the liquid composition B in the present disclosure described above.

  In the present disclosure, “content of each component in liquid composition B” refers to the content of each component when using liquid composition B, ie, when liquid composition B is used for immersing a silicon wafer. Say.

  In the present disclosure, the liquid composition B is produced as a concentrate, and may be used as diluted at the time of use. The concentrate of the liquid composition B can be used by diluting with water so that the content of each component becomes the above-mentioned content at the time of use. In the present disclosure, the “when in use” of the liquid composition concentrate refers to the state in which the liquid composition B concentrate is diluted in one or more embodiments.

  The pH of the liquid composition B is preferably 3 or more, more preferably 4 or more, from the viewpoint of reducing residue on the wafer surface, and 11 or less is preferable, 10 or less is more preferable, from the viewpoint of suppressing Haze deterioration. The following is more preferable. More specifically, the pH of the liquid composition B is preferably 3 or more and 11 or less, more preferably 3 or more and 10 or less, still more preferably 3 or more and 9 or less, and still more preferably 4 or more and 9 or less. In the present disclosure, the pH of the liquid composition B is a value at 25 ° C., which can be measured using a pH meter, and specifically, can be measured by the method described in the examples.

  The temperature of the liquid composition B is preferably 10 ° C. or more, more preferably 13 ° C. or more, still more preferably 15 ° C. or more, still more preferably 18 ° C. or more, from the viewpoint of reducing residue on the wafer surface. From the viewpoint, 40 ° C. or less is preferable, 30 ° C. or less is more preferable, and 25 ° C. or less is more preferable. From the same viewpoint, the temperature of the liquid composition B is preferably 10 ° C. to 40 ° C., preferably 13 ° C. to 40 ° C., more preferably 15 ° C. to 40 ° C., and still more preferably 18 ° C. to 40 ° C. More preferably, it is more than 18 ° C. and not more than 30 ° C., and more preferably, more than 18 ° C. and not more than 25 ° C.

  In the step (2), the immersion time of the silicon wafer obtained in the step (1) in the liquid composition B is preferably 1 minute or more, more preferably 5 minutes or more, from the viewpoint of reducing the residue on the wafer surface. 10 minutes or more is more preferable, and from the same viewpoint, 120 minutes or less is preferable, 90 minutes or less is more preferable, 60 minutes or less is preferable, and 45 minutes or less is more preferable. From the same viewpoint, the immersion time is preferably 1 minute to 120 minutes, more preferably 5 minutes to 90 minutes, still more preferably 10 minutes to 60 minutes, and still more preferably 10 minutes to 45 minutes.

In the step (2), the ratio of the area of the surface of the silicon wafer (m ² ) to the amount of the liquid composition B (L) (area / amount of the liquid composition B) is from the viewpoint of reducing the residue on the wafer surface 0.01 or more is preferable, 0.02 or more is more preferable, 0.03 or more is more preferable, and from the same viewpoint, 0.1 or less is preferable, 0.08 or less is more preferable, 0.06 or less Is more preferred. From the same viewpoint, the ratio of the surface area (m ² ) of the silicon wafer to the amount (L) of the liquid composition B is preferably 0.01 or more and 0.1 or less, and more preferably 0.02 or more and 0.08 or less. Preferably, 0.03 or more and 0.06 or less are more preferable.

[Step (3): Cleaning Step]
The step (3) is a step (cleaning step) of cleaning the silicon wafer obtained in the step (2) using the cleaning composition C. The detergent composition C is, in one or more embodiments, a detergent composition substantially free of the component b1, wherein the detergent composition C is substantially free of the component b1. The content of the component b1 in the detergent composition C is less than 0.008% by mass, preferably substantially 0% by mass. In one or more embodiments, the cleaning composition C preferably contains substantially no organic compound from the viewpoint of improving the cleaning properties. Here, the content of the organic compound in the detergent composition C is 0.1% by mass or less, preferably 0.05% by mass or less, that the detergent composition C does not substantially contain the organic compound. Preferably, it is substantially 0% by mass. One embodiment of the cleaning composition C includes, for example, an inorganic cleaning agent containing at least one selected from hydrogen peroxide, ammonia, hydrochloric acid, sulfuric acid, hydrofluoric acid and ozone water.

  The cleaning in the step (3) is preferably an inorganic cleaning from the viewpoint of reducing the residue on the wafer surface, and, for example, generally used RCA cleaning or SCROD cleaning can be used.

The RCA cleaning basically includes an SC1 cleaning used to remove particles attached to the wafer surface and an SC2 cleaning used to remove heavy metals attached to the wafer surface, as needed. This includes SPM cleaning used to remove surface-deposited organic matter, and DHF cleaning used to remove unwanted oxide film on the wafer surface. SCROD cleaning is used for particle removal and heavy metal removal. Examples of the cleaning method of the RCA cleaning and the SCROD cleaning include a dip cleaning method and a single wafer cleaning method.
In the SC1 cleaning, for example, a cleaning agent composition comprising ammonia, hydrogen peroxide and water is used. In the SC2 cleaning, for example, a cleaning agent composition comprising hydrochloric acid, hydrogen peroxide solution and water is used. In the SPM cleaning, for example, a cleaning composition composed of sulfuric acid and hydrogen peroxide solution is used. In DHF cleaning, for example, a cleaning agent composition comprising hydrofluoric acid and water is used. In SCROD cleaning, ozone water or hydrofluoric acid is used.
After each washing step of the washing described above, the steps of rinsing with water and drying may be included.

  Hereinafter, the present disclosure will be described in more detail by way of examples, but these are illustrative and the present disclosure is not limited to these examples.

1. Preparation of Liquid Composition B Component b1 (nonionic surfactant) or non-component b1 shown in Tables 1 and 2 is mixed with water and mixed, and the liquid compositions of Examples 1 to 28 and Comparative Examples 1 to 8 Preparation B was prepared. Citric acid and ammonia were used for pH adjustment.

In the preparation of liquid compositions B of Examples 1 to 28 and Comparative Examples 1 to 8 shown in Tables 1 and 2, the following were used as the component b1 and the non-component b1. In addition, in the following description, the numerical value in () represents an average added mole number.
(Component b1)
Example 1: Polyoxyethylene alkyl ether [linear alkyl group; carbon number 12, ethylene oxide; average addition mole number 6]
Example 2, 21 to 23: polyoxyethylene alkyl ether [linear alkyl group; carbon number 12, ethylene oxide; average addition mole number 9]
Example 3: Polyoxyethylene alkyl ether [linear alkyl group; carbon number 12, ethylene oxide; average addition mole number 12]
Example 4: Polyoxyethylene alkyl ether [linear alkyl group; carbon number 18, ethylene oxide; average addition mole number 13]
Example 5: Polyoxyethylene alkenyl ether [linear alkyl group; carbon number 18, containing one unsaturated bond, ethylene oxide; average addition mole number 9]
Example 6: Polyoxyethylene alkenyl ether [straight chain alkyl group; carbon number 18, containing one unsaturated bond, ethylene oxide; average addition mole number 13]
Examples 7, 19, 20: Polyoxyethylene alkyl ether [C12-14 carbon atoms of branched alkyl group, ethylene oxide; average addition mole number 7]
Example 8: polyoxyethylene alkyl ether [branched alkyl group; carbon number 12-14, ethylene oxide average added mole number 12]
Example 9: polyoxyethylene-polyoxypropylene-polyoxyethylene alkyl ether [linear alkyl group; 12 to 14 carbon atoms, ethylene oxide (4) propylene oxide (0.2) ethylene oxide (4); block type]
Example 10: polyoxyethylene-polyoxypropylene-polyoxyethylene alkyl ether [linear alkyl group; carbon number 12-14, ethylene oxide (9) propylene oxide (2) ethylene oxide (9); block type]
Example 11: polyoxyethylene-polyoxypropylene-polyoxyethylene alkyl ether [linear alkyl group; carbon number 12-14, ethylene oxide (4) propylene oxide (2) ethylene oxide (4); block type]
Examples 12, 24 to 26: polyoxyethylene-polyoxypropylene-polyoxyethylene alkyl ether [linear alkyl group; 12 to 14 carbon atoms, ethylene oxide (3) propylene oxide (1.5) ethylene oxide (3); block Type]
Example 13: polyoxyethylene-polyoxypropylene-polyoxyethylene alkyl ether [branched alkyl group; carbon number 12-14, ethylene oxide (5) propylene oxide (2) ethylene oxide (5); block type]
Example 14: alkyl polyglucoside [linear alkyl group; carbon number 10-16]
Example 15: alkyl polyglycerin ether [linear alkyl group; carbon number 12]
Example 16: polyoxyethylene styrenated phenol [average ethylene oxide addition mole number 13]
Example 17: polyoxyethylene tribenzylated phenol [average added mole number of ethylene oxide 14]
Examples 18, 27, 28: polyoxyethylene-polyoxypropylene alkyl ether [branched alkyl group: carbon number 2, 2-ethylhexyl group, ethylene oxide average addition mole number 9, propylene oxide average addition mole number 5, block type, terminal PO ]
(Non-component b1)
Comparative Example 1: Water Comparative Example 2: Citric Acid Comparative Example 3: Polyoxyethylene alkyl ether [linear alkyl group; carbon number 12, ethylene oxide; average addition mole number 47]
Comparative Example 4: Polyoxyethylene alkyl ether [linear alkyl group; carbon number 18, ethylene oxide; average addition mole number 50]
Comparative Example 5: Polyoxyethylene alkenyl ether [linear alkyl group; carbon number 18, containing one unsaturated bond, ethylene oxide; average addition mole number 30]
Comparative example 6: polyoxyethylene nonylated phenol [ethylene oxide; average addition mole number 29]
Comparative Example 7: Polyoxyethylene tribenzylated phenol [average added mole number of ethylene oxide 30]
Comparative Example 8: polyoxyethylene-polyoxypropylene-polyoxyethylene block polymer [Asahi Denka Co., Pluronic F108]

2. Measurement methods of various parameters (1) Component b1 (nonionic surfactant) and surface tension of non-component b1 Component b1 or non-component b1 aqueous solution (solid content is as described in Tables 1 and 2) The pH of component b1 or non-component b1 diluted with pure water was adjusted to 4, 7, 9 and 11. Citric acid and ammonia were used for pH adjustment as needed. Then, the pH-adjusted aqueous solution (25 ° C.) is placed in a petri dish, and used a surface tension meter ("CBVP-Z" manufactured by Kyowa Interface Chemicals Co., Ltd.) by the Wilhelmy method (a method of immersing a platinum plate and pulling it up at a constant speed). The surface tension was measured. The measurement results are shown in Tables 1 and 2.

(2) pH of polishing composition A and liquid composition B
The pH value at pH 25 ° C. of the polishing composition A and the liquid composition B is a value measured using a pH meter (“HM-30G” manufactured by Toa Denpa Kogyo Co., Ltd.), and the electrode composition of the pH meter is a polishing composition It is a numerical value after 1 minute immersion in the thing A or the liquid composition B.

(3) Average secondary particle size of abrasive grains (silica particles) The average secondary particle size (nm) of the silica particles is diluted with ion exchange water so that the concentration of the silica particles is 0.15 mass%, The resulting aqueous solution is placed in a Disposable Sizing Cuvette (polystyrene, 10 mm cell) to a height of 10 mm from the bottom, and dynamic light scattering (apparatus name: Zetasizer Nano ZS, manufactured by Sysmex Corporation) at 25 ° C. The measurement was carried out under the conditions of integration 10 times and equilibrium time 0 minutes. The refractive index of water is 1.333 and the absorption coefficient is 0 as particle parameters, and the Z average value is defined as the average secondary particle diameter.

3. Evaluation [Removability]
Evaluation of the removability of the residue on the wafer surface was performed as follows. The evaluation results are shown in Tables 1 and 2.
(1) A silicon wafer (crystal surface 100, resistivity: 1 to 100 Ω · cm) cut into 4 cm × 4 cm was treated with a 1% by mass hydrofluoric acid aqueous solution for silicon water repellency.
(2) Silica particles (colloidal silica, average secondary particle diameter 70 nm, "PL-3" manufactured by Sakai Chemical Co., Ltd.), HEC (weight average molecular weight 800,000, "CF-V" manufactured by Sumitomo Seika Chemicals Co., Ltd.), ammonia And ultrapure water were mixed to prepare a polishing composition A. The content of each component in the polishing composition A is 0.3% by mass of silica particles, 0.015% by mass of HEC, 0.015% by mass of ammonia, and the remainder is ultrapure water. The pH of the polishing composition A was 10.7.
(3) The silicon wafer subjected to silicon water repellent treatment was immersed in 100 mL of the prepared polishing composition A (temperature 25 ° C.) for 1 minute.
(4) The silicon wafer was pulled out of the polishing composition A and washed with running water for 5 seconds.
(5) The water-washed silicon wafer (surface area 0.0016 m ² ) was immersed in 0.1 L of each of the prepared liquid compositions B (temperature 25 ° C.). The immersion time is shown in Tables 1 and 2.
(6) The silicon wafer was gently removed from the liquid composition B, and the Si concentration (ppb) in the liquid composition B was measured using a nuclear inductively coupled plasma mass spectrometer (ICP-MS, manufactured by Agilent, 7700 S) . The measurement results are shown in Tables 1 and 2. It can be judged that the higher the Si concentration in the liquid composition B, the more the residue is removed from the wafer surface, and the more the residue on the wafer surface is reduced.

  As shown in Tables 1 and 2, in Examples 1 to 28 using a liquid composition containing a predetermined nonionic surfactant (component b1), the polished silicon was compared to Comparative Examples 1 to 8. The removability of the residue on the wafer surface was improved.

[Bubbling ability]
The component b2 (defoamer, compounding amount: 1000 ppm) shown in Table 3 was further blended to the liquid composition B of Example 7, and the lathering property was evaluated.
Specifically, an aqueous solution containing component b1 (nonionic surfactant) and component b2 (defoamer) shown in Table 3 was prepared, and 30 g of the aqueous solution was charged into a 50 ml screw tube. The lid was closed and the screw was shaken up and down for 20 seconds. After standing, the distance from the bottom of the screw tube to the top of the bubbling liquid was measured. The difference from the distance from the liquid surface before shaking the screw tube was regarded as bubbling ability.

The following were used for the component b2 shown in Table 3.
(Component b2: antifoaming agent)
Example 29: Alkylene oxide antifoamer [BASF, Pluronic PE10100]
Example 30: Alkylene oxide defoamer [BASF, Pluronic PE 6100, average molecular weight 2,000]
Example 31: Alkylene oxide antifoamer [BASF, Pluronic PE10400]
Example 32: alcohol alkoxylate antifoamer [BASF, Plurafac LF300]
Example 33: Alkylene oxide antifoamer [Cognis, Dehypon LS24]
Example 34: Alkylene oxide antifoamer [Cognis, Dehypon LS36, structure (abbreviation): R- (EO) 3 (PO) 6]
Example 35: Alkylene oxide antifoamer [Cognis, Dehypon LS45]
Example 36: Alkylene oxide antifoamer [Cognis, Dehypon LT54, structure (abbreviation): R- (EO) 5 (PO) 4]
Example 37: Alkylene oxide antifoamer [Cognis, Dehypon 104L]
Example 38: Alkylene oxide antifoamer [Cognis, Dehypon supra]
Example 39: Phosphate ester antifoamer [BASF, Degressal SD20]
Example 40: Phosphate ester antifoamer [BASF, Degressal SD21]
Example 41: polypropylene glycol antifoamer [Asahi Glass Co., Ltd., Exenol 3030, average molecular weight 3,000]
Example 42: Polypropylene glycol antifoamer [Asahi Glass Co., Ltd., Exenol 3020, average molecular weight 3,200]
Example 43: Polypropylene glycol antifoamer [Asahi Glass Co., Ltd., Exenol S4011, average molecular weight 10,000]
Example 44: silicone antifoamer [Toray Dow Corning, FS anti-foam 25]
Example 45: silicone antifoamer [Toray Dow Corning FS Antifoam 80]
Example 46: silicone antifoamer [Toray Dow Corning FS Antifoam 92]
Example 47: silicone antifoamer [Toray Dow Corning, FS anti-foam 544]
Example 48: Silicone antifoamer [Toray Dow Corning, DK Q1-71]
Example 49: silicone antifoamer [Toray Dow Corning, DK Q1-1247]

  As shown in Table 3, Examples 29-49, which contain the given non-ionic surfactant (component b1) and antifoam (component b2), compared to Example 7 which does not contain antifoam. Foaming was suppressed. From the comparison of Examples 29 to 43 with Examples 44 to 49, it was found that silicone antifoaming agents are preferable in terms of lathering property.

  According to the present disclosure, since the residue on the surface of a polished silicon wafer can be reduced, a silicon wafer with reduced surface defects can be manufactured, which is useful in mass production of semiconductor substrates.

Claims (18)

The manufacturing method of a silicon wafer including following process (1), (2) and (3).
(1) A step of polishing the surface of the silicon wafer to be polished using the polishing composition A.
(2) A step of immersing the silicon wafer obtained in the step (1) in a liquid composition B containing a nonionic surfactant b1.
(3) A step of cleaning the silicon wafer obtained in the step (2) using the cleaning composition C.
However, the surface tension of the nonionic surfactant b1 is 43 N / m or less,
The polishing composition A and the cleaning composition C are substantially free of the nonionic surfactant b1.   The manufacturing method of the silicon wafer of Claim 1 whose immersion time to the liquid composition B of a silicon wafer is 120 minutes or less in a process (2).   The liquid composition B according to claim 1 or 2, wherein the liquid composition B substantially does not contain a type 1 designated compound designated in the Act on the promotion of the improvement of management and the grasp of the emission amount of a specific chemical substance to the environment. Method of manufacturing silicon wafer.   The hydrophobic group of the nonionic surfactant b1 is at least one selected from a branched alkyl group, an unsaturated alkyl group, a naphthyl group, a styrenated phenol group, and a benzylated phenol group. A method of manufacturing a silicon wafer according to any one of the above.   The method for producing a silicon wafer according to any one of claims 1 to 4, wherein the hydrophilic group of the nonionic surfactant b1 is a block structure of an ethyleneoxy group and a propyleneoxy group.   The method for producing a silicon wafer according to any one of claims 1 to 5, wherein the hydrophilic group of the nonionic surfactant b1 is a block structure of an ethyleneoxy group and a propyleneoxy group, and the terminal is a propylene oxide group. .   The manufacturing method of the silicon wafer in any one of Claim 1 to 6 whose compounding quantity of nonionic surfactant b1 in the liquid composition B is more than critical micelle concentration and 0.008 mass% or more.   The method for producing a silicon wafer according to any one of claims 1 to 7, wherein the liquid composition B further comprises an antifoaming agent b2.   The method for producing a silicon wafer according to any one of claims 1 to 8, wherein the pH of the liquid composition B is 3 or more and 11 or less.   The method for producing a silicon wafer according to any one of claims 1 to 9, wherein the polishing composition A contains abrasive grains and a water-soluble polymer other than the nonionic surfactant b1.   11. The silicon wafer according to any one of claims 1 to 10, wherein the cleaning agent composition C is an inorganic cleaning agent containing at least one selected from hydrogen peroxide, ammonia, hydrochloric acid, sulfuric acid, hydrofluoric acid and ozone water. Production method.   A liquid composition for storing a silicon wafer, containing a nonionic surfactant b1 having a surface tension of 43 N / m or less at a critical micelle concentration or more.   The liquid composition according to claim 12, wherein the pH is 3 or more and 11 or less.   The hydrophobic group of the nonionic surfactant b1 according to claim 12 or 13, wherein the hydrophobic group is at least one selected from a branched alkyl group, an unsaturated alkyl group, a naphthyl group, a styrenated phenol group, and a benzylated phenol group. Liquid composition.   The liquid composition according to any one of claims 12 to 14, wherein the hydrophilic group of the nonionic surfactant b1 is a block structure of ethylene oxide and propylene oxide.   The liquid composition according to any one of claims 12 to 15, wherein the hydrophilic group of the nonionic surfactant b1 is a block structure of ethylene oxide and propylene oxide, and the terminal is propylene oxide.   The liquid composition according to any one of claims 12 to 16, wherein the content of the nonionic surfactant b1 is not less than the critical micelle concentration and not less than 0.008% by mass.   A liquid composition according to any one of claims 12 to 17 for use in step (2) in the method for producing a silicon wafer according to any one of claims 1 to 11.