KR20220136084A - Method for manufacturing substrate and surface treatment method - Google Patents

Abstract

The present invention provides means capable of sufficiently removing residue remaining on the surface of a polished polishing object having a layer containing a silicon-containing material. The present invention provides a manufacturing method of a substrate comprising a step of forming a layer containing a water-soluble polymer on a surface of the polished polishing object having a layer containing a silicon-containing material. The substrate has the thickness of the layer containing the water-soluble polymer 2 nm or more and 22 nm or less.

Description

The manufacturing method and surface treatment method of a board|substrate TECHNICAL FIELD

The present invention relates to a method for manufacturing a substrate and a method for surface treatment.

BACKGROUND ART In recent years, along with multilayer wiring on the surface of a semiconductor substrate, a so-called chemical mechanical polishing (CMP) technique of physically polishing and planarizing a semiconductor substrate has been used when manufacturing a device. CMP is a method of planarizing the surface of an object to be polished (object to be polished) such as a semiconductor substrate by using a polishing composition (slurry) containing abrasive grains such as silica, alumina, and ceria, an anticorrosive agent, a surfactant, etc., and polishing The object (object to be polished) is silicon, polysilicon, silicon oxide, silicon nitride, wiring, plugs, or the like containing metal or the like.

A large amount of impurities (also referred to as "foreign matter" or "defect") remain on the surface of the semiconductor substrate after the CMP process. Impurities include, but are not limited to, abrasive grains derived from the polishing composition used in CMP, organic substances such as metals, anticorrosive agents, and surfactants, silicon-containing materials to be polished, silicon-containing materials and metals generated by polishing metal wires or plugs, and various pads. Organic matter, such as pad debris, etc. which generate|occur|produce from etc. are contained.

When the semiconductor substrate surface is contaminated with these impurities, the electrical properties of the semiconductor are adversely affected and the reliability of the device may be lowered. Therefore, it is preferable to introduce a cleaning process after the CMP process to remove these impurities from the semiconductor substrate surface.

As such a cleaning composition, for example, Japanese Patent Application Laid-Open No. 2012-74678 (corresponding to US Patent Application Laid-Open No. 2013/174867) discloses, for example, a polycarboxylic acid or hydroxycarboxylic acid and a sulfonic acid type anionic interface. A cleaning composition for semiconductor substrates containing an activator, a carboxylic acid-type anionic surfactant, and water is disclosed, whereby foreign substances can be removed without corroding the substrate surface.

However, in the technique of Japanese Patent Application Laid-Open No. 2012-74678 (corresponding to the specification of U.S. Patent Application Laid-Open No. 2013/174867), in the cleaning of a polished object having a layer containing a silicon-containing material, foreign matter ( There was a problem that the residue) could not be sufficiently removed.

Then, an object of the present invention is to provide means capable of sufficiently removing the surface residues of a polished object having a layer containing a silicon-containing material.

MEANS TO SOLVE THE PROBLEM The present inventors earnestly examined the said subject in consideration. As a result, the above problem is solved by a method for manufacturing a substrate comprising forming a layer containing a water-soluble polymer having a thickness in a specific range on the surface of a polished object having a layer containing a silicon-containing material found out and completed the present invention.

That is, one aspect for solving the above problems of the present invention is a method of manufacturing a substrate, comprising forming a layer containing a water-soluble polymer on the surface of a polished object having a layer containing a silicon-containing material, , The thickness of the layer containing the water-soluble polymer is 2 nm or more and 22 nm or less, a method of manufacturing a substrate.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described. In addition, this invention is not limited only to the following embodiment. In addition, in this specification, unless otherwise noted, operation and measurement of physical properties, etc. are performed under the conditions of room temperature (20 degreeC or more and 25 degrees C or less)/relative humidity 40%RH or more and 50%RH or less.

A method for manufacturing a substrate according to one embodiment of the present invention includes forming a layer containing a water-soluble polymer on the surface of a polished object having a layer containing a silicon-containing material, the layer containing the water-soluble polymer has a thickness of 2 nm or more and 22 nm or less. According to such a manufacturing method according to one embodiment of the present invention, it is possible to sufficiently remove surface residues of a polished object having a layer containing a silicon-containing material.

The present inventors speculate as follows the mechanism by which the surface residues of a polished polishing object can be removed by such a structure.

That is, by forming a layer containing a water-soluble polymer (hereinafter simply referred to as a "water-soluble polymer layer") on the surface of the polished object to be polished, re-adhesion of residues (contaminants) to the surface of the polished object can be prevented. have. In addition, when the thickness of the water-soluble polymer layer is 2 nm or more and 22 nm or less, the adhesion (adhesive force) of the water-soluble polymer and the residue on the surface of the polished object is lowered, and the residue is detached from the water-soluble polymer on the surface of the polished object. becomes easy, and as a result, it is considered that residues can be sufficiently removed from the surface of the polished object to be polished.

In addition, the said mechanism is based on a guess, and this invention is not limited at all to the said mechanism.

EMBODIMENT OF THE INVENTION Hereinafter, although embodiment of this invention is described in detail, this invention is not limited only to the following embodiment. In the present specification, unless otherwise specified, operation and measurement of physical properties are performed under conditions of room temperature (20°C or more and 25°C or less)/relative humidity of 40% RH or more and 50% RH or less.

<residue>

In the present specification, the term "residue" refers to a foreign material adhering to the surface of the polished object. Examples of the residue are not particularly limited, but include, for example, organic residues described later, particle residues derived from abrasive grains contained in the polishing composition, particle residues and residues containing components other than organic residues, particle residues and mixtures of organic residues Other residues, such as etc., are mentioned.

In this specification, the total number of residues shows the total number of all residues regardless of a kind. The total number of residues can be measured using a wafer defect inspection apparatus. The detail of the measuring method of the number of residues is described in the Example mentioned later.

In the present specification, the term "organic residue" refers to a component containing an organic substance such as an organic low molecular weight compound or a high molecular compound, or an organic salt, among foreign substances adhering to the surface of the polished object.

The organic residue adhering to the polished object is, for example, pad debris generated from a pad used in a polishing step or rinse polishing step to be described later, or a polishing composition used in the polishing step or used in the rinse polishing step. and components derived from additives contained in the rinse polishing composition.

In addition, since the color and shape of the organic substance residue and other foreign substances are significantly different, the determination of whether the foreign substance is an organic substance residue is performed using, for example, a scanning electron microscope (SEM) SU8000 (manufactured by Hitachi High-Tech Corporation). It can be performed visually by SEM observation. In addition, you may judge whether a foreign material is an organic substance residue by elemental analysis by the energy dispersive X-ray analyzer (EDX) attached to SEM as needed. The number of organic residues can be measured using a wafer defect inspection apparatus and SEM or EDX elemental analysis.

<Polished object to be polished>

In the present specification, the polished object to be polished means the object to be polished after being polished in the polishing step. Although a polishing process in particular is not restrict|limited, It is preferable that it is a CMP process.

The polished object according to the present invention has a layer containing a silicon-containing material. As an example of a silicone-containing material, single-piece silicone and a silicone compound are mentioned, for example. As an example of single-crystal silicon, monocrystalline silicon, polycrystalline silicon (polysilicon), amorphous silicon, etc. are mentioned, for example. As an example of a silicon compound, silicon nitride, a silicon oxide, a silicon carbide, silicon germanium, etc. are mentioned, for example. The silicon-containing material also includes a low-dielectric constant material having a relative permittivity of 3 or less. Further, n-type impurity-doped polysilicon and p-type impurity-doped polysilicon are also included in the concept of a polished object according to the present invention. These silicon-containing materials may be used alone or in combination of two or more.

The polished object according to the present invention may contain other materials as long as it has a layer containing a silicon-containing material. Examples of other materials include carbon and metal. Further, examples of carbon include crystalline carbon and amorphous carbon. Examples of the metal include tungsten, copper, aluminum, hafnium, cobalt, nickel, titanium, tantalum, gold, silver, platinum, palladium, rhodium, ruthenium, iridium, and osmium. These metals may be contained in the form of an alloy or a metal compound. These metals may be used individually by 1 type or in combination of 2 or more types may be sufficient as them.

[Method for manufacturing substrate]

The method for manufacturing a substrate of the present invention includes forming a layer containing a water-soluble polymer having a thickness of 2 nm or more and 22 nm or less on the surface of a polished object having a layer containing a silicon-containing material. The method of forming the layer containing the water-soluble polymer is not particularly limited, but it is preferably a method of treating the surface of the polished object by using a surface treatment composition containing the water-soluble polymer.

Hereinafter, the said surface treatment composition and its manufacturing method, and the method (surface treatment method) of treating the surface of a polished polishing object using the said surface treatment composition are demonstrated.

(Surface treatment composition)

It is preferable that the surface treatment composition which concerns on this invention contains a water-soluble polymer. The water-soluble polymer as used herein refers to a water-soluble polymer having the same repeating unit (homopolymer; homopolymer), or a water-soluble polymer (copolymer; copolymer) having different repeating units, typically having a weight average molecular weight (Mw ) may be 1000 or more compounds. The kind of polymer used as the water-soluble polymer is not particularly limited, and any of anionic, cationic, nonionic and amphoteric can be used. In the case where the water-soluble polymer is a copolymer, the form of the copolymer may be any of a block copolymer, a random copolymer, a graft copolymer, an alternating copolymer and a periodic copolymer.

Examples of the anionic water-soluble polymer include, for example, polyvinylsulfonic acid, polystyrenesulfonic acid, polyallylsulfonic acid, polymethallylsulfonic acid, poly(2-acrylamide-2-methylpropanesulfonic acid), polyisoprenesulfonic acid, polyacrylic acid, polymethacrylic acid mountains, and the like.

Examples of the cationic water-soluble polymer include polyethyleneimine (PEI), polyvinylamine, polyallylamine, polyvinylpyridine, and cationic acrylamide polymer. As a specific example of polyallylamine, polydiallyl dimethylammonium chloride etc. can be used, for example.

Examples of the nonionic water-soluble polymer include, for example, polyvinyl alcohol, ethylene/vinyl alcohol copolymer, polyvinylpyrrolidone, polyacrylamide, polyN-vinylacetamide, polyamines, polyvinyl ethers (polyvinyl methyl ether). , polyvinyl ethyl ether, polyvinyl isobutyl ether, etc.), polyalkylene oxides (polyethylene oxide, polypropylene oxide, etc.), polyglycerin, polyethylene glycol, polypropylene glycol, water-soluble cellulose (hydroxyethyl cellulose (HEC), polysaccharides such as hydroxypropyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, ethyl cellulose, and ethyl hydroxyethyl cellulose), alginic acid polyhydric alcohol esters, water-soluble urea resins, dextrin derivatives, and casein have. In addition, not only those having such a main chain structure, but also graft copolymers having a nonionic polymer structure in the side chain can be suitably used.

Examples of the amphoteric water-soluble polymer include, for example, a copolymer of a vinyl monomer having an anionic group and a vinyl monomer having a cationic group, a vinyl-based amphoteric polymer having a carboxybetaine group or a sulfobetaine group, specifically acrylic acid /Diethylaminoethylmethacrylic acid copolymer, acrylic acid/diethylaminoethylmethacrylic acid copolymer, etc. are mentioned.

Furthermore, copolymers of water-soluble polymers exemplified above can also be used.

A water-soluble polymer can be used individually by 1 type or in combination of 2 or more types. In addition, a commercial item may be used for water-soluble polymer, and a synthetic product may be used for it.

Among these water-soluble polymers, nonionic water-soluble polymers are preferable from the viewpoint of making it easy to detach from the substrate after rinsing and polishing, and polyvinyl alcohol, ethylene/vinyl alcohol copolymer, polyN-vinylacetamide, and hydroxyethyl cellulose (HEC) are preferred. , hydroxypropyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose and ethyl cellulose are more preferable.

The lower limit of the weight average molecular weight (Mw) of the water-soluble polymer is preferably 1,000 or more, more preferably 1,500 or more, still more preferably 2,000 or more, and still more preferably 5,000 or more. The upper limit of the weight average molecular weight (Mw) of the water-soluble polymer is preferably 1,500,000 or less, more preferably 800,000 or less, still more preferably 500,000 or less, still more preferably 100,000 or less, and even more preferably 80,000 or less. do. That is, the weight average molecular weight (Mw) of the water-soluble polymer is preferably 1,000 or more and 1,500,000 or less, more preferably 1,500 or more and 800,000 or less, still more preferably 2,000 or more and 500,000 or less, even more preferably 5,000 or more and 100,000 or less, and even more preferably 5,000 or more. It is especially more preferable that it is 80,000 or less. In addition, the weight average molecular weight (Mw) of a water-soluble polymer can be measured as a value in terms of polyethylene glycol using gel permeation chromatography (GPC).

The content of the water-soluble polymer in the surface treatment composition is appropriately set according to the type of the water-soluble polymer to be used, but the lower limit of the content makes the total mass of the surface treatment composition 100 mass%, preferably 0.01 mass% or more, and 0.05 mass% % or more is more preferable, and 0.1 mass % or more is still more preferable. Moreover, the upper limit of content of the water-soluble polymer in the surface treatment composition makes the total mass of the surface treatment composition 100 mass %, 10 mass % or less is preferable, 5.0 mass % or less is more preferable, 1.0 mass % or less is further desirable. That is, the content of the water-soluble polymer in the surface treatment composition is 100 mass% of the total mass of the surface treatment composition, preferably 0.01 mass% or more and 10 mass% or less, more preferably 0.05 mass% or more and 5.0 mass% or less, 0.1 mass % or more and 1.0 mass % or less are more preferable.

In addition, when a surface treatment composition contains 2 or more types of water-soluble polymer, content of a water-soluble polymer intends these total amounts.

<Surfactant>

It is preferable that the surface treatment composition which concerns on this invention further contains surfactant from a viewpoint of improving the effect of this invention more. There is no restriction|limiting in particular in the kind of surfactant, Any of nonionic, anionic, cationic, and amphoteric surfactant may be sufficient.

As an example of a nonionic surfactant, For example, alkyl ether types, such as polyoxyethylene lauryl ether and polyoxyethylene oleyl ether; alkylphenyl ether types such as polyoxyethylene octylphenyl ether; alkyl ester types such as polyoxyethylene laurate; alkylamine types, such as polyoxyethylene laurylamino ether; alkylamide types such as polyoxyethylene lauric acid amide; polypropylene glycol ether types such as polyoxyethylene polyoxypropylene ether; alkanolamide types such as oleic acid diethanolamide; Allylphenyl ether types, such as polyoxyalkylene allylphenyl ether, etc. are mentioned. In addition, propylene glycol, diethylene glycol, monoethanolamine, alcohol ethoxylate, alkylphenol ethoxylate, tertiary acetylene glycol, alkanolamide, etc. can also be used as a nonionic surfactant.

As an example of anionic surfactant, For example, Carboxylic acid types, such as sodium myristate, sodium palmitate, sodium stearate, sodium laurate, potassium laurate; sulfuric acid ester types such as sodium octylsulfonate; phosphate ester types such as lauryl phosphate and sodium lauryl phosphate; Sulfonic acid types, such as sodium dioctyl sulfosuccinate and sodium dodecyl benzene sulfonate, etc. are mentioned.

As an example of cationic surfactant, For example, amines, such as laurylamine hydrochloride; quaternary ammonium salts such as polyethoxyamine and lauryl trimethylammonium chloride; Pyridinium salts, such as lauryl pyridinium chloride, etc. are mentioned.

Examples of the amphoteric surfactant include alkyl betaines and sulfobetaines such as lecithin, alkylamine oxide, N-alkyl-N,N-dimethylammonium betaine, and the like.

Surfactant can be used individually by 1 type or in combination of 2 or more types. In addition, a commercial item may be used for surfactant, and a synthetic product may be used for it.

Among these surfactants, nonionic or anionic surfactants are preferable, and nonionic surfactants are more preferable from the viewpoint of making it easy to detach from the substrate after rinsing and polishing.

When the surface treatment composition contains a surfactant, the lower limit of the content of the surfactant is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, with the total mass of the surface treatment composition being 100% by mass, more preferably 0.01 It is more preferable that it is mass % or more. Further, the upper limit of the content of the water-soluble polymer in the surface treatment composition is 100 mass% of the total mass of the surface treatment composition, preferably 5.0 mass% or less, more preferably 1.0 mass% or less, more preferably 0.5 mass% or less desirable. That is, the surfactant content in the surface treatment composition is preferably 0.001 mass% or more and 5.0 mass% or less, with the total mass of the surface treatment composition being 100 mass%, more preferably 0.005 mass% or more and 1.0 mass% or less, more preferably 0.01 It is more preferable that they are mass % or more and 0.5 mass % or less.

In addition, when a surface treatment composition contains 2 or more types of surfactant, content of surfactant intends these total amounts.

<solvent>

The surface treatment composition according to the present invention may contain a solvent. The solvent has a function of dispersing or dissolving each component. It is preferable that water is included, and, as for a solvent, it is more preferable that it is only water. In addition, the mixed solvent of water and an organic solvent may be sufficient as a solvent for dispersion|distribution or dissolution of each component. In this case, examples of the organic solvent used include acetone, acetonitrile, ethanol, methanol, isopropanol, glycerin, ethylene glycol, propylene glycol, and triethanolamine, which are water-miscible organic solvents. In addition, after using these organic solvents without mixing with water and disperse|distributing or melt|dissolving each component, you may mix with water. These organic solvents can be used individually or in combination of 2 or more types.

Although content of the water in a surface treatment composition is not specifically limited, 60 mass % or more is preferable, 70 mass % or more is more preferable, 80 mass % or more is still more preferable, 90 mass % or more is still more preferable, 95 mass % or more is more preferable. % or more is especially preferable, 97 mass % or more is the most preferable, for example, 99 mass % or more may be sufficient. If the content of water in the surface treatment composition is within the above range, the effect of the present invention tends to be further exhibited.

The water is preferably water containing no residue as much as possible from the viewpoint of preventing contamination of the polished object and inhibiting the action of other components. For example, water having a total content of transition metal ions of 100 ppb or less is preferable. Here, the purity of water can be improved by operation, such as removal of the residual ion using an ion exchange resin, removal of the foreign material by a filter, distillation, for example. Specifically, it is preferable to use, for example, deionized water (ion-exchanged water), pure water, ultrapure water, distilled water, or the like.

<Other additives>

The surface treatment composition which concerns on this invention is the range which does not impair the effect of this invention, and may contain other additives in arbitrary ratios as needed. However, since it is preferable not to contain components other than the essential component of the surface treatment composition which concerns on this invention as much as possible since it may cause a residue, it is preferable that the content is as small as possible. Although it does not restrict|limit especially as an example of another additive, For example, an abrasive grain, a mold inhibitor, a preservative, a reducing agent, an oxidizing agent, etc. are mentioned.

<pH and pH adjuster>

The lower limit of the pH of the surface treatment composition according to the present invention is not particularly limited, but is preferably 1 or more, more preferably 2 or more, still more preferably 3 or more, still more preferably 4 or more, and particularly preferably 5 or more. desirable. The upper limit of the pH is not particularly limited, but is preferably 12 or less, more preferably 11 or less, still more preferably 10 or less, still more preferably 9 or less, particularly preferably 8 or less, particularly preferably 7 or less. Most preferably, 6 or less may be sufficient, for example. If it is within this range, the possibility of deteriorating the consumable members such as the polishing apparatus and the contacting polishing pad is further reduced, and the possibility of occurrence of residues and scratches due to the product generated by the deterioration is also further reduced. In addition, the pH value of the surface treatment composition can be confirmed with the pH meter (Product name: LAQUA (trademark) by Horiba Corporation).

The pH value of the surface treatment composition can be adjusted with a pH adjuster.

The pH adjuster in particular is not restrict|limited, The well-known pH adjuster used in the field|area of a surface treatment composition can be used. Among these, it is preferable to use a well-known acid, a base, or these salts. Examples of the pH adjusting agent include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enantic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, mar Garic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, docosahexaenoic acid, eicosapentaenoic acid, lactic acid, malic acid, citric acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, mellitic acid, sour carboxylic acids such as namic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, aconitic acid, amino acid, and anthranilic acid, and organic acids such as sulfonic acid and organic phosphonic acid; inorganic acids such as nitric acid, carbonic acid, hydrochloric acid, phosphoric acid, hypophosphorous acid, phosphorous acid, phosphonic acid, boric acid, hydrofluoric acid, orthophosphoric acid, pyrophosphoric acid, polyphosphoric acid, metaphosphoric acid, and hexametaphosphoric acid; hydroxides of alkali metals such as potassium hydroxide (KOH); hydroxides of Group 2 elements; ammonia (ammonium hydroxide); Organic bases, such as a quaternary ammonium hydroxide compound, etc. are mentioned.

A synthetic product may be used for a pH adjuster, and a commercial item may be used for it. In addition, these pH adjusters can be used individually or in combination of 2 or more types.

What is necessary is just to select suitably the quantity used as the pH value of a desired surface treatment composition for content of the pH adjuster in a surface treatment composition.

(Method for producing surface treatment composition)

The manufacturing method of the surface treatment composition which concerns on this invention, Preferably, the water-soluble polymer which concerns on this invention, a solvent, and other components are mixed as needed. For example, the surface treatment composition according to the present invention can be obtained by stirring and mixing the water-soluble polymer according to the present invention, a solvent, and, if necessary, other components. Although the temperature in particular at the time of mixing each component is not restrict|limited, 10 degreeC or more and 40 degrees C or less are preferable, and in order to raise a dissolution rate, you may heat. Also, the mixing time is not particularly limited.

[Surface treatment method]

As described above, the method for manufacturing a substrate of the present invention includes forming a layer containing a water-soluble polymer having a thickness of 2 nm or more and 22 nm or less on the surface of a polished object having a layer containing a silicon-containing material. The method for forming the layer containing the water-soluble polymer is not particularly limited, but it is preferably a surface treatment method in which the surface of the polished object is treated using a surface treatment composition containing the water-soluble polymer. Therefore, according to another aspect of the present invention, the surface of a polished object having a layer containing a silicon-containing material is treated with a surface treatment composition containing a water-soluble polymer, and the layer containing the silicon-containing material is treated. A surface treatment method comprising forming a layer containing the water-soluble polymer on the surface of a polished object having a .

In this specification, the surface treatment refers to a treatment for removing residues on the surface of a polished object, and refers to a treatment for performing cleaning in a broad sense. The surface treatment method according to one embodiment of the present invention is performed by a method in which the surface treatment composition is brought into direct contact with a polished object to be polished. Although the surface treatment in particular is not restrict|limited, For example, it is preferable to perform by rinse-polishing process or a washing process.

It is preferable that the surface treatment method which concerns on one aspect of this invention is the method by a rinse-polishing process. The reason for this is that it becomes possible to more efficiently obtain a layer of water-soluble polymer having a desired thickness.

In the present specification, the rinse polishing treatment is performed on a polishing platen (platen) provided with a polishing pad, and is water-soluble on the surface of a polished polishing object by the frictional force (physical action) of the polishing pad and the action of the surface treatment composition. A treatment for forming a polymer layer and a treatment for removing residues on the surface of the polished object are shown. As a specific example of the rinse polishing treatment, after the final polishing (finish polishing) is performed on the polishing object, the polished object is placed on a polishing platen (platen) of the polishing apparatus, and the polished object and the polishing pad are brought into contact with each other, A process of relatively sliding the polished object and the polishing pad while supplying the surface treatment composition to the contact portion is exemplified.

More specifically, the rinse polishing treatment is performed using a general polishing apparatus having a holder for holding the object to be polished, a motor capable of changing the rotation speed, etc., and having a polishing platen to which a polishing pad (polishing cloth) can be attached. it is preferable As the polishing apparatus, either a single-side polishing apparatus or a double-side polishing apparatus may be used. As the polishing pad, general nonwoven fabric, polyurethane, porous fluororesin, and the like can be used without particular limitation. Among them, a more preferable polishing pad is polyurethane. It is preferable that the grooving|grooving process in which a polishing liquid accumulates is given to the polishing pad. In addition, when chemical mechanical polishing and rinsing polishing are performed using the same polishing apparatus, the polishing apparatus is provided with a discharge nozzle of the surface treatment composition according to one embodiment of the present invention in addition to the discharge nozzle of the polishing composition. desirable.

Conditions for rinsing polishing are not particularly limited, and suitable conditions can be appropriately set depending on the surface treatment composition and characteristics of the polished object to be polished. The grinding pressure (polishing load) at the time of grinding|polishing becomes important. In general, when the polishing pressure (polishing load) during rinse polishing is high, the thickness of the water-soluble polymer layer becomes thin, and when the polishing pressure (polishing load) during rinse polishing is low, the thickness of the water-soluble polymer layer becomes thick.

The lower limit of the polishing pressure (polishing load) during rinse polishing is preferably more than 0.2 psi (1.38 kPa), more preferably 0.3 psi (2.07 kPa) or more, still more preferably 0.4 psi (2.76 kPa) or more, , more preferably 0.5 psi (3.45 kPa) or more, even more preferably 0.7 psi (4.83 kPa) or more, and particularly preferably 1 psi (6.9 kPa) or more. Further, the upper limit of the polishing pressure (polishing load) is preferably less than 5 psi (34.8 kPa), more preferably 4.5 psi (30.1 kPa) or less, still more preferably 4.0 psi (26.6 kPa) or less, and 3.5 psi (24.1) or less. kPa) or less, and more preferably 3.0 psi (20.9 kPa) or less. That is, the polishing pressure (polishing load) during rinse polishing is preferably more than 0.2 psi (1.38 kpa) and less than 5 psi (34.8 kpa), more preferably 0.3 psi (2.07 kpa) or more and 4.5 psi (30.1 kpa) or less. and more preferably 0.4 psi (2.76 kpa) or more and 4.0 psi (26.6 kpa) or less, even more preferably 0.5 psi (3.45 kPa) or more and 3.5 psi (24.1 kPa) or less, and 0.7 psi (4.83 kPa) or more and 3.5 psi (24.1 kPa) or less is particularly preferable, and it is most preferably 1 psi (6.9 kPa) or more and 3.0 psi (20.9 kPa) or less. When the water-soluble polymer is PNVA, the polishing pressure (polishing load) during rinse polishing is particularly preferably 1 psi (6.9 kPa) or more and 2 psi (13.8 kPa) or less. If the polishing pressure (polishing load) at the time of rinse polishing is within this range, it becomes easy to form a water-soluble polymer layer having a desired thickness, and residues can be removed efficiently.

The polishing time during rinse polishing may be appropriately set so that a water-soluble polymer layer having a desired thickness is obtained, and is not particularly limited, but generally, it is preferably 5 seconds or more, more preferably 10 seconds or more, and 15 seconds or more. more preferably, and even more preferably 20 seconds or longer. Further, from the viewpoint of efficiently removing residues, the polishing time during rinse polishing is preferably 180 seconds or less, more preferably 150 seconds or less, still more preferably 120 seconds or less, and even more preferably 100 seconds or less. .

The number of rotations of the surface plate may be appropriately set so as to obtain a water-soluble polymer layer having a desired thickness, and is not particularly limited. In general, 10 rpm (0.17 s ^-1 ) or more and 500 rpm (8.3 s ^-1 ) or less are preferable, 20 rpm (0.33 s ^-1 ) or more and 300 rpm (5s ^-1 ) or less are more preferable, 30 rpm (0.5 s ^-1 ) or less ) or more and 200 rpm (3.3s ^-1 ) or less is more preferable.

The method in particular of supplying a surface treatment composition is not restrict|limited, either, You may employ|adopt the method of supplying continuously with a pump etc. (flowing type). The supply amount of the surface treatment composition (flow rate of the surface treatment composition) is not particularly limited as long as it covers the entire polished object to be polished, but is generally preferably 100 mL/min or more and 5000 mL/min or less.

In addition, the method by a washing|cleaning process may be sufficient as the surface treatment method, as long as the layer containing the water-soluble polymer with a thickness of 2 nm or more and 22 nm or less is obtained. In the present specification, the cleaning treatment refers to a process of removing residues on the surface of a polished abrasive object mainly by a chemical action by a surface treatment composition, performed in a state in which the polished object is separated on a polishing platen (platen). indicates As a specific example of the cleaning treatment, for example, after the final polishing (finish polishing) is performed on the object to be polished, or after the final polishing is followed by a rinse polishing treatment, the polished object is separated on a polishing platen (platen), , a treatment in which the polished object is brought into contact with the surface treatment composition. In the contact state of the surface treatment composition and the polished object, a means for applying a frictional force (physical action) to the surface of the polished object may be further used.

The washing treatment method, the washing treatment apparatus, and the washing treatment conditions are not particularly limited, and well-known methods, apparatuses, conditions, and the like can be appropriately used. The cleaning treatment method is not particularly limited, but for example, a method of immersing a polished object in a surface treatment composition and performing ultrasonic treatment as necessary, or a cleaning brush and a polishing finish while holding the polished object and a method of rubbing the surface of the polished object with a brush while contacting the object to be polished and supplying a surface treatment composition to the contact portion.

Washing with water may be performed before, after, or both of the process of performing the surface treatment method which concerns on one aspect of this invention. Thereafter, the water droplets adhering to the surface of the polished object may be blown off with a spin dryer, air blow, or the like and dried.

<Thickness of water-soluble polymer layer>

In the substrate manufacturing method and surface treatment method according to the present invention, the thickness of the water-soluble polymer layer formed on the polished object to be polished is 2 nm or more and 22 nm or less. When the thickness is less than 2 nm, the residue tends to adhere to the polished object, and the removal of the residue becomes difficult. On the other hand, when the thickness exceeds 22 nm, the viscoelasticity of the water-soluble polymer layer increases, the action of entanglement between the residue and the water-soluble polymer increases, and the removal of the residue becomes difficult. The lower limit of the thickness of the water-soluble polymer layer is preferably 3 nm or more, more preferably 5 nm or more. Moreover, the upper limit of the thickness of a water-soluble polymer layer becomes like this. Preferably it is 20 nm or less, More preferably, it is 15 nm or less. That is, it is preferable that they are 3 nm or more and 20 nm or less, and, as for the thickness of a water-soluble polymer layer, it is more preferable that they are 5 nm or more and 15 nm or less.

In addition, in this invention, the thickness of a water-soluble polymer layer employ|adopts the value measured by spectroscopic ellipsometry. The detail of the measuring method of the thickness of a water-soluble polymer layer is as having described in an Example.

<Adhesive strength>

The water-soluble polymer layer having the thickness as described above has a small adhesive force with the residue, thereby facilitating the removal of the residue. Regarding the adhesive force between the residue and the water-soluble polymer layer, the adhesive strength of the water-soluble polymer layer with respect to the SiO ₂ probe when measured with an atomic force microscope (AFM) using a SiO ₂ probe can be used as an index. The SiO ₂ probe is composed of the same compound as the silica abrasive grains generally used in polishing, and the smaller the adhesive strength of the water-soluble polymer layer to the SiO ₂ probe, the easier it is to remove residues from the polished object. have. That is, according to one preferred embodiment of the present invention, the adhesive strength of the layer containing the water-soluble polymer to the SiO ₂ probe as measured by an atomic force microscope using a SiO ₂ probe is 5.0 nN or less. Further, the adhesive strength tends to be proportional to the radius of curvature at the tip of the SiO ₂ probe.

The adhesive strength is preferably 5.0 nN or less, more preferably 4.0 nN or less, still more preferably 3.0 nN or less, still more preferably 2.0 nN or less, particularly preferably 1.0 nN or less, and most preferably 0.5 nN or less. Preferably, for example, less than 0.45 nN may be sufficient, typically 0.3 nN or less may be sufficient, and 0.15 nN or less may be sufficient. Moreover, it is preferable that it is 0 nN or more, as for the lower limit of the said adhesive strength, it is more preferable that it is 0.001 nN or more, It is still more preferable that it is 0.01 nN or more.

The detail of the measuring method of the said adhesive strength is as having described in an Example.

[Method for manufacturing semiconductor substrate]

As described above, in the method for manufacturing a substrate according to an embodiment of the present invention, a layer containing a water-soluble polymer having a thickness of 2 nm or more and 22 nm or less is formed on the surface of a polished object having a layer containing a silicon-containing material. includes doing In particular, the method for manufacturing a substrate according to an embodiment of the present invention is suitably applied when the polished object to be polished is a polished semiconductor substrate. That is, according to another preferred embodiment of the present invention, the polished object to be polished is a polished semiconductor substrate, and the polished semiconductor substrate contains a water-soluble polymer on the surface of the polished semiconductor substrate by the surface treatment method. Also provided is a method for manufacturing a semiconductor substrate comprising forming a layer, wherein the layer comprising the water-soluble polymer has a thickness of 2 nm or more and 22 nm or less.

About the detail of the semiconductor substrate to which such a manufacturing method is applied, it is as having demonstrated the polished object surface-treated with the said surface treatment composition.

Further, the method for manufacturing a substrate includes a step (surface treatment step) of surface-treating the surface of a polished object (preferably a polished semiconductor substrate) using the surface treatment composition according to one embodiment of the present invention. If it is, it is not particularly limited. As such a manufacturing method, for example, a method having a polishing step and a surface treatment step for forming a polished object to be polished is mentioned. Hereinafter, these processes are demonstrated.

[Polishing process]

In the method of manufacturing a substrate according to a preferred embodiment of the present invention, the step of obtaining the polished object is a step of polishing the polished object (preferably a semiconductor substrate) to form the polished object.

The polishing step is not particularly limited as long as it is a step of polishing an object to be polished (preferably a semiconductor substrate), but it is preferably a Chemical Mechanical Polishing (CMP) step. In addition, the grinding|polishing process may be a grinding|polishing process containing a single process, or the grinding|polishing process containing a plurality of processes may be sufficient as it. As a polishing step including a plurality of steps, for example, a step of performing a finish polishing step after the preliminary polishing step (rough polishing step), or a step of performing a secondary polishing step once or twice or more after the primary polishing step, and the The process of performing a finish-polishing process later, etc. are mentioned. It is preferable if the surface treatment process using the surface treatment composition which concerns on this invention is performed after the said finish-polishing process.

As the polishing composition, a known polishing composition can be appropriately used depending on the characteristics of the semiconductor substrate, and for example, a polishing composition containing an abrasive grain, a dispersion medium and an acid can be preferably used. Specific examples of such a polishing composition include a polishing composition containing colloidal silica, water, and maleic acid.

As the polishing apparatus, a general polishing apparatus having a holder for holding a polishing object, a motor capable of changing the rotational speed, and the like, and a polishing platen to which a polishing pad (polishing cloth) can be attached can be used. As the polishing apparatus, either a single-side polishing apparatus or a double-side polishing apparatus may be used.

As the polishing pad, general nonwoven fabric, polyurethane, porous fluororesin, and the like can be used without particular limitation. Among them, a more preferable polishing pad is polyurethane. It is preferable that the grooving|grooving process in which a polishing liquid accumulates is given to the polishing pad.

There is no particular limitation on the polishing conditions, for example, the number of rotations of the polishing platen and the number of rotations of the head (carrier) is preferably 10 rpm (0.17 s ^-1 ) or more and 100 rpm (1.67 s ^-1 ) or less, and the pressure applied to the polishing object It is preferable that (polishing pressure) is 0.5 psi (3.45 kPa) or more and 10 psi (68.9 kPa) or less. The method of supplying the polishing composition to the polishing pad is not particularly limited, for example, a method of continuously supplying the polishing composition with a pump or the like (flowing method) is adopted. Although there is no restriction on this supply amount, it is preferable that the surface of the polishing pad is always covered with the polishing composition, preferably 10 mL/min or more and 5000 mL/min or less, more preferably 20 mL/min or more and 4000 mL/min or less, 30 mL/min or more and 4000 mL/min or less More preferably at least 3000 mL/min, even more preferably at least 35 mL/min and at most 2000 mL/min, particularly preferably at least 40 mL/min and at most 1000 mL/min, most preferably at least 45 mL/min and at most 500 mL/min. , for example, may be 50 mL/min or more and 300 mL/min or less, and typically 55 mL/min or more and 150 mL/min or less. The polishing time is also not particularly limited, but for the step of using the polishing composition, it is preferably 5 seconds or more and 180 seconds or less, more preferably 10 seconds or more and 150 seconds or less, and still more preferably 15 seconds or more and 120 seconds or less.

[Surface treatment process]

The surface treatment step refers to a step including forming a layer containing a water-soluble polymer on the surface of a polished object and reducing residues using the surface treatment composition according to the present invention. In the manufacturing method of a semiconductor substrate, after a rinse-polishing process, the washing|cleaning process as a surface treatment process may be performed, and only a rinse-polishing process or only a washing|cleaning process may be performed.

Details of the rinse polishing method and the cleaning method used in the rinse polishing step and the cleaning step are as described in the description of the rinse polishing treatment and the cleaning treatment.

In the method for manufacturing a substrate according to the present invention, for the steps other than the polishing step and the surface treatment step, a step applicable to a known method for manufacturing a semiconductor substrate can be appropriately employed.

Although embodiment of this invention has been described in detail, it is clear that this is explanatory and illustrative, and it is not restrictive, and that the scope of the present invention should be construed by the appended claims.

The present invention includes the following aspects and forms.

1. A method of manufacturing a substrate, comprising forming a layer containing a water-soluble polymer on the surface of a polished object having a layer containing a silicon-containing material, wherein the layer containing the water-soluble polymer has a thickness of 2 nm or more 22 nm or less, a method of manufacturing a substrate;

2. The manufacturing method according to 1. above, wherein the adhesive strength of the layer containing the water-soluble polymer to the SiO ₂ probe is 5.0 nN or less when measured with an atomic force microscope using a SiO ₂ probe;

3. The production according to 1. or 2., wherein the formation of the layer containing the water-soluble polymer includes rinsing and polishing the surface of the polished object to be polished using the surface treatment composition containing the water-soluble polymer. Way;

4. The manufacturing method according to 3. above, wherein the polishing pressure during the rinse polishing treatment is greater than 0.2 psi and less than 5 psi;

5. The manufacturing method according to any one of 1. to 4. above, wherein the water-soluble polymer is a nonionic water-soluble polymer;

6. The manufacturing method according to any one of 3. to 5. above, wherein the surface treatment composition containing the water-soluble polymer further contains a surfactant;

7. The manufacturing method according to 6. above, wherein the surfactant is a nonionic surfactant;

8. A surface of a polished object having a layer containing a silicon-containing material is surface treated using a surface treatment composition containing a water-soluble polymer, and the surface of a polished object having a layer containing the silicon-containing material In, as a surface treatment method comprising forming a layer containing the water-soluble polymer, the thickness of the layer containing the water-soluble polymer is 2 nm or more and 22 nm or less, the surface treatment method;

9. The surface treatment method according to 8. above, wherein the surface treatment is a rinse polishing treatment;

10. The surface treatment method according to 9., wherein the polishing pressure during the rinse polishing treatment is greater than 0.2 psi and less than 5 psi.

[Example]

The present invention will be described in more detail using the following examples and comparative examples. However, the technical scope of the present invention is not limited only to the following examples. In addition, unless otherwise indicated, "%" and "part" mean "mass %" and "part by mass", respectively. In addition, in the following example, unless otherwise indicated, operation was performed under the conditions of room temperature (25 degreeC)/relative humidity 40%RH or more and 50%RH or less.

[Preparation of water-soluble polymer]

PolyN-vinylacetamide (PNVA having a weight average molecular weight (Mw) of 50,000, manufactured by Showa Denko Co., Ltd.), and polyvinyl alcohol (PVA having a weight average molecular weight (Mw) of 10,000 (PVA (saponification degree 99%)), Japan Sakubi/Poval Co., Ltd.) was prepared. In addition, the weight average molecular weight of the water-soluble polymer was measured by the following method.

[Measurement of weight average molecular weight (Mw) of water-soluble polymer]

As the weight average molecular weight (Mw) of the water-soluble polymer, the value of the weight average molecular weight (in terms of polyethylene glycol) measured by gel permeation chromatography (GPC) was used. The weight average molecular weight was measured by the following apparatus and conditions:

GPC device: manufactured by Shimadzu Corporation, Ltd.

Format: Prominence +ELSD detector (ELSD-LTII)

Column: VP-ODS (manufactured by Shimadzu Corporation)

Mobile phase A: MeOH

B: acetic acid 1% aqueous solution

Flow rate: 1 mL/min

Detector: ELSD temp.40℃, Gain 8, N ₂ GAS 350kPa

Oven temperature: 40℃

Injection volume: 40 μL.

[Preparation of surface treatment composition]

(Preparation Example 1)

Surface treatment composition 1 was prepared by mixing polyN-vinylacetamide as a water-soluble polymer and water (deionized water) as a solvent. Here, content of the water-soluble polymer was 0.2 mass % with respect to the total amount of the surface treatment composition 1, and the pH of the surface treatment composition 1 was 5.9.

(Preparation Example 2)

Surface treatment composition 2 was prepared by mixing polyvinyl alcohol which is a water-soluble polymer and water (deionized water) as a solvent. Here, content of the water-soluble polymer was 0.2 mass % with respect to the total amount of the surface treatment composition 2, and the pH of the surface treatment composition 2 was 4.4.

[Measurement of pH of surface treatment composition]

The pH of the surface treatment composition (liquid temperature: 25°C) was confirmed with a pH meter (product name: LAQUA (registered trademark) manufactured by Horiba Corporation).

[Preparation of polished object to be polished]

A polished polysilicon substrate after being polished by the following chemical mechanical polishing (CMP) process was prepared as a polished polishing object.

(CMP process)

As a polishing object, a 12-inch polycrystalline silicon (polysilicon) wafer (manufactured by Advanced Materials Technology, Ltd.) was prepared.

With respect to the polysilicon substrate prepared above, the polishing composition (composition: colloidal silica (average primary particle diameter of 30 nm, average secondary particle diameter of 60 nm) 4% by mass, concentration of 30% by mass of maleic acid aqueous solution 0.018% by mass, solvent: water ) was used, and polishing was performed under the following conditions:

<Grinding device and polishing conditions>

Polishing device: FREX300E manufactured by Ebara Seisakusho, Ltd.

Polishing pad: Foamed polyurethane pad H800 manufactured by Fujibo Holdings Co., Ltd. Polishing pressure: 2.0 psi (1 psi=6894.76 Pa, hereinafter the same)

Grinding plate rotation speed: 80rpm

Head rotation speed: 80rpm

Supply of polishing composition: flow-through type

Polishing composition feed rate: 200 mL/min

Grinding time: 30 seconds.

(Rinse polishing process)

(Example 1)

The polished object obtained by polishing the surface of the object to be polished in the CMP process was separated on a polishing platen (platen). Subsequently, in the same polishing apparatus, the polished object is placed on another polishing platen (platen), and the surface of the polished object is polished using the surface treatment composition 1 prepared in Preparation Example 1 under the following conditions. A rinse-polishing treatment was performed on:

<Rinse polishing apparatus and rinse polishing conditions>

Polishing device: FREX300E manufactured by Ebara Seisakusho, Ltd.

Polishing pad: Fujibo Holdings Co., Ltd. foamed polyurethane pad H800 surface treatment composition supply amount: 300 mL/min

Rinse polishing time: 10 seconds

Rinse abrasive pressure: 0.5 psi (3.4 kPa)

Spindle rotation speed: 60rpm.

(Examples 2 to 20)

A rinse polishing treatment was performed in the same manner as in Example 1, except that the polishing time and polishing pressure were changed as shown in Table 1 below.

(Examples 21 to 40)

Using the surface treatment composition 2 prepared in Preparation Example 2 above, except that the polishing time and polishing pressure were changed as shown in Table 2 below, in the same manner as in Example 1, rinse polishing was performed.

(Examples 41 to 42)

With respect to the said surface treatment composition 1, the surface treatment composition 3 which added dodecylbenzenesulfonic acid so that it might become 0.05 mass % was prepared. The pH of the surface treatment composition 3 was 5.6. Using this surface treatment composition 3, a rinse polishing treatment was performed in the same manner as in Example 1 except that the polishing time and polishing pressure were changed as shown in Table 3 below.

(Examples 43 to 44)

With respect to the said surface treatment composition 2, the surface treatment composition 4 which added oleic acid diethanolamide so that it might become 0.05 mass % was prepared. The pH of the surface treatment composition 4 was 5.8. Using this surface treatment composition 4, except having changed the polishing time and polishing pressure as shown in Table 3 below, in the same manner as in Example 1, a rinse polishing treatment was performed.

(Comparative Examples 1 to 4)

Surface treatment composition 5 was prepared by mixing polyN-vinylacetamide as a water-soluble polymer and water (deionized water) as a solvent. Here, content of the water-soluble polymer was 0.2 mass % with respect to the total amount of the surface treatment composition 1, and the pH of the surface treatment composition 5 was 5.9.

Using this surface treatment composition 5, except having changed the polishing time and polishing pressure as shown in Table 3 below, in the same manner as in Example 1, a rinse polishing treatment was performed.

(Comparative Example 5)

A rinse polishing treatment was performed in the same manner as in Example 10 except that deionized water was used instead of the surface treatment composition 1.

(cleaning process)

In the rinse polishing step, the polysilicon substrate obtained by rinsing the surface of the polished polishing object (hereinafter also referred to as "rinsing polished polishing object") is respectively placed on a polishing platen (platen) with a cleaning device attached to the polishing apparatus. (cleaner tank part). Thereafter, using water (deionized water), while applying pressure with a sponge made of polyvinyl alcohol (PVA), which is a cleaning brush, a cleaning treatment was performed on the surface of the object to be rinsed and polished under the following conditions:

<Cleaning device and cleaning conditions>

Washing device: FREX300E made by Ebara Seisakusho Co., Ltd.

Cleaning brush rotation speed: 100 rpm

Grinding completed Grinding object rotation speed: 100rpm

Type of cleaning composition: water (deionized water)

Cleaning composition feed rate: 1000 mL/min

Cleaning time: 60 seconds.

[evaluation]

In the measurement of the thickness and adhesive strength of the water-soluble polymer layer, a rinse-polished polishing object subjected to a rinse-polishing step was prepared.

(Measurement of thickness of water-soluble polymer layer)

The rinse-polished-polished object after the rinse-polishing process was completed was cut out to a square of 20 mm, and was measured by spectroscopic ellipsometry (manufactured by Horiba, Ltd., model UVISEL Plus). In addition, the measurement was performed in the state which immersed the sample in the glass cell filled with pure water.

(Measurement of adhesive strength)

The rinse-polished polishing object at the stage where the rinse-polishing process was completed was cut out to a 10 mm square, and the adhesive strength between the residue and the water-soluble polymer layer was measured using an atomic force microscope (AFM). The measuring apparatus and measuring conditions are shown below. The force curve measurement was performed in pure water, and the force measured just before the probe in a return path jumped out was made into adhesive strength. The smaller the value of the adhesive strength, the easier it is for the residue to detach:

Measuring device: S-I Nanotechnology Co., Ltd. model S-image/NanonaviII

Probe: Model qp-scont manufactured by Nano World, 10 nm radius of curvature at the tip Material SiO ₂

Sampling frequency: 1Hz

Scanning range: -1 nm to +200 nm.

(Measure the number of residues)

The number of residues having a diameter of 65 nm or more remaining on the surface of the polysilicon substrate (cleaned polishing object) after the cleaning process was measured using Surfscan (registered trademark) SP5, manufactured by KLA Tenko Corporation. In addition, a section of 5 mm of the outer periphery of the cleaned polishing object was excluded from the measurement area.

The evaluation results are shown in Tables 1 to 3 below.

As is clear from the above Tables 1 to 3, it was found that the production method of the Example reduced the residue on the surface of the polished object as compared with the production method of the comparative example. In the case of Examples 41-44 using the surface treatment composition containing surfactant, it turned out that a residue reduces more.

In addition, this application is based on the Japanese Patent Application No. 2021-59470 for which it applied on March 31, 2021, The whole is taken in into this specification by reference.

Claims (10)

A method of manufacturing a substrate, comprising: forming a layer containing a water-soluble polymer on a surface of a polished object having a layer containing a silicon-containing material, the method comprising:
The thickness of the layer comprising the water-soluble polymer is 2 nm or more and 22 nm or less, a method of manufacturing a substrate. The method according to claim 1, wherein the adhesive strength of the layer containing the water-soluble polymer to the SiO ₂ probe is 5.0 nN or less when measured by an atomic force microscope using a SiO ₂ probe. The production according to claim 1 or 2, wherein the formation of the layer containing the water-soluble polymer comprises rinsing and polishing the surface of the polished object using a surface treatment composition containing the water-soluble polymer. Way. The manufacturing method according to claim 3, wherein the polishing pressure during the rinse polishing treatment is greater than 0.2 psi and less than 5 psi. The method according to claim 1, wherein the water-soluble polymer is a nonionic water-soluble polymer. The method according to claim 3, wherein the surface treatment composition including the water-soluble polymer further comprises a surfactant. 7. The method of claim 6, wherein the surfactant is a nonionic surfactant. A surface of a polished object having a layer containing a silicon-containing material is subjected to surface treatment using a surface treatment composition containing a water-soluble polymer, and the surface of the polished object having a layer containing the silicon-containing material is applied to the surface of the polished object; As a surface treatment method comprising forming a layer containing the water-soluble polymer,
The thickness of the layer containing the water-soluble polymer is 2 nm or more and 22 nm or less, a surface treatment method. The surface treatment method according to claim 8, wherein the surface treatment is a rinse polishing treatment. The surface treatment method according to claim 9, wherein the polishing pressure during the rinse polishing treatment is greater than 0.2 psi and less than 5 psi.