Patent Description:
Conventionally, in the process of manufacturing a substrate, debris may be generated, for example, by a lithography process or the like. Therefore, the substrate manufacturing process may include a cleaning step for removing particles on the substrate. In the cleaning step, there are methods such as a method for physically removing particles by supplying a cleaning solution such as deionized water (DIW) on the substrate and a method for chemically removing particles with chemicals. However, as patterns become finer and more complicated, they become more susceptible to physical or chemical damage.

In addition, as a substrate cleaning step, there is a method for forming a film on a substrate to remove particles.

Patent Document <NUM> studies a substrate cleaning composition in which polymer having a special partial structure that essentially contains fluorine is used for forming a film, in order to obtain an affinity to a stripping solution and a dissolution rate.

Patent Document <NUM> studies a substrate cleaning apparatus which completely dissolves and removes a film formed by solidifying or curing a processing liquid on a substrate with a remover.

Patent document <NUM> studies a substrate cleaning apparatus which removes a film (particle holding layer) from a substrate by dissolving in a remover a solvent which remains in a particle holding layer.

Patent documents <NUM> to <NUM> disclose different compositions comprising polymeric components, alkaline components and solvents.

The inventors considered that in the technology of forming a film on a substrate to remove particles, one or more problems still need to be improved. They include, for example, the followings: removal of particles is insufficient; films are not formed uniformly and particles remain; films formed do not peel off from the substrate; films formed are not removed sufficiently and they become solid waste; when it is attempted to use a material having fluorine or the like, the synthesis becomes complicated; there is no portion in the film which becomes a trigger that the formed film peels; the held particles are detached and reattached on the substrate due to complete dissolution of a film; process control is required to leave the organic solvent in the film; and the substrate is damaged by using alkaline solution such as ammonia to remove or peel off the film.

The present invention has been made based on the technical background as described above and provides a method for cleaning a substrate using a substrate cleaning solution.

The present invention provides a method for cleaning a substrate comprising (<NUM>) dripping a substrate cleaning solution on a substrate; (<NUM>) removing a solvent (C) in the substrate cleaning solution, and a polymer (A) forms a film; (<NUM>) making the film to hold particles on the substrate; and (<NUM>) applying a remover (F) on the substrate to remove the film in which the particles are held, the substrate cleaning solution comprising a polymer (A), an alkaline component (B), and a solvent (C), provided that the alkaline component (B) does not comprise ammonia, wherein the alkaline component (B) is represented by at least one of the formulae (B-<NUM>), (B-<NUM>), and (B-<NUM>):
<CHM>
wherein L<NUM> is -CH<NUM>-, -CH<NUM>-CH<NUM>-, -CH<NUM>-CH<NUM>-CH<NUM>-, or the formula (B-<NUM>)':
<CHM>
where nb1 is <NUM> or <NUM>, nb2 is <NUM> or <NUM>, and nb1 + nb2 is not equal to <NUM>,.

The substrate cleaning solution used according to the present invention may further comprise a crack accelerating component (D).

In one embodiment of the present invention, the substrate cleaning solution is dripped on a substrate and dried to remove the solvent (C), and the polymer (A) forms a film. Preferably, the alkaline component (B) and /or the crack accelerating component (D) remain in the film on the substrate, and are not removed together with the solvent (C).

In the present invention, the film obtained by the substrate cleaning solution is removed by a remover (F). Preferably, the remover (F) is neutral or mildly acidic.

The present invention provides a device manufacturing method, comprising cleaning a substrate by the method of the invention, and further processing the su bstrate.

Using the substrate cleaning solution in the method of the present invention, it is possible to desire one or more of the following effects. It is possible to sufficiently remove particles; it is possible to form a film uniformly and to reduce the remaining amount of particles; it is possible to sufficiently peel off the formed film from the substrate and to remove it; there is no need to use materials having fluorine or the like, whose synthesis is complicated; since there is a portion, which becomes a trigger that the film peels, in the film, it is possible to sufficiently remove the film; since there is no need to dissolve most of the film to remove, it is possible to prevent the detachment of the held particles; it is possible to make unnecessary the process control for leaving the organic solvent in the film; and since there is no need to use alkaline solution such as ammonia to remove or peel off the film, it is possible to prevent the substrate damaged.

The above summary and the following details are intended to explain the present invention and not to limit the claimed invention.

In the present specification, unless otherwise specifically mentioned, the singular includes the plural and "one" or "that" means "at least one". In the present specification, unless otherwise specifically mentioned, an element of a concept can be expressed by a plurality of species, and when the amount (for example, mass % or mol%) is described, it means sum of the plurality of species.

"And/or" includes a combination of all elements and also includes single use of the element.

In the present specification, when a numerical range is indicated using "to" or "-", unless otherwise specifically mentioned, it includes both endpoints and units thereof are common. For example, <NUM> to <NUM> mol% means <NUM> mol% or more and <NUM> mol% or less.

In the present specification, the descriptions such as "Cx-y", "Cx-Cy" and "Cx" mean the number of carbons in a molecule or substituent. For example, C<NUM>-<NUM> alkyl means an alkyl chain having <NUM> or more and <NUM> or less carbons (methyl, ethyl, propyl, butyl, pentyl, hexyl etc.).

In the present specification, when polymer has a plural types of repeating units, these repeating units copolymerize. Unless otherwise specifically mentioned, these copolymerization may be any of alternating copolymerization, random copolymerization, block copolymerization, graft copolymerization, or a mixture thereof. When polymer or resin is represented by a structural formula, n, m or the like that is attached next to parentheses indicate the number of repetitions.

In the present specification, unless otherwise specifically mentioned, Celsius is used as the temperature unit. For example, <NUM> degrees means <NUM> degrees Celsius.

The substrate cleaning solution used according to the present invention comprises a polymer (A), an alkaline component (B), and a solvent (C), provided that the alkaline component (B) does not comprise ammonia, wherein the alkaline component (B) is represented by at least one of the formulae (B-<NUM>), (B-<NUM>), and (B-<NUM>).

As a preferred embodiment, the substrate cleaning solution is dripped on a substrate and dried to remove the solvent (C), and the polymer (A) forms a film. As a preferred embodiment, the alkaline component (B) and /or a below-mentioned crack accelerating component (D) remain in the film, and are not removed together with the solvent (C). One embodiment of "film formation" is "solidification". Furthermore, it is enough that the film obtained from the substrate cleaning solution has a hardness to the extent to hold particles, and the solvent (C) is not required to be completely removed (for example, through vaporization). The substrate cleaning solution becomes a film while gradually shrinking as the solvent (C) vaporizes. As for the "not removed with the solvent", it is accepted that an extremely small amount is removed (for example, vaporization, volatilization) in comparison with the whole. For example, it is accepted that <NUM> - <NUM> mass % (preferably <NUM> - <NUM> mass %, more preferably <NUM> - <NUM> mass %, further preferably <NUM> - <NUM> mass %, and still more preferably <NUM> - <NUM> mass %) relative to the original amount is removed.

Although this is not intended to limit the scope of the invention and not to be bound by theory, it is considered that the film holds particles on the substrate and is removed by being peeled off by a remover (F) that is described later. When the alkaline component (B) remains in the film, it is considered that the alkaline component (B) dissolves in the remover (F) and pH of the remover (F) is raised during peeling off the film by the remover (F). Thus, the remover (F) is no need to be alkaline solution such as ammnonia. When the alkaline component (B) and/or the crack accelerating component (D) remains in the film, it is considered that a portion which becomes a trigger that the film peels is generated.

The substrate cleaning solution used according to the present invention comprises a polymer (A).

The polymer (A) preferably comprises at least one of novolak, polyhydroxy styrene, polystyrene, polyacrylate derivatives, polymaleic acid derivatives, polycarbonate, polyvinyl alcohol derivatives, polymethacrylate derivatives, and copolymer of any combination of any of these. Preferably, the polymer (A) comprises at least one of novolak, polyhydroxystyrene, polyacrylic acid derivatives, polycarbonate, polymethacrylic acid derivatives, and copolymer of any combination of any of these. More preferably, the polymer (A) comprises at least one of novolak, polyhydroxystyrene, polycarbonate, and copolymer of any combination of any of these. Novolac may be phenol novolac.

It is described for clarity that the substrate cleaning solution used according to the present invention may comprise one or more of the above-mentioned preferred examples in combination as the polymer (A). For example, the polymer (A) may contain both novolak and polyhydroxystyrene.

It is a preferable embodiment of the present invention that the polymer (A) is dried to form a film, and the film is peeled off while holding particles without being mostly dissolved by the below-mentioned remover (F), which can contain the dissolved alkaline component (B). In addition, the embodiment in which a very few portions of the polymer (A) is dissolved by the remover (F) is accepted.

Preferably, the polymer (A) does not contain fluorine and/or silicon, and more preferably, it contains neither of them.

The above-mentioned copolymerization is preferably random copolymerization or block copolymerization.

Although it is not intended to limit the present invention, exemplified examples of the polymer (A) include the followings:
<CHM>
<CHM>.

R represents a substituent such as a C<NUM>-<NUM> alkyl.

The weight-average molecular weight (Mw) of the polymer (A) is <NUM> - <NUM>,<NUM>, more preferably <NUM> - <NUM>,<NUM>, further preferably <NUM> - <NUM>,<NUM>, and still more preferably <NUM>,<NUM> - <NUM>,<NUM>.

The polymer (A) can be obtained through synthesis thereof. It is also possible to purchase it. When purchasing, examples of the supplier are indicated below. It is also possible that the supplier synthesizes the polymer (A) so as to make the effects of the present invention be exhibited.

In one embodiment of the present invention, compared with the total mass of the substrate cleaning solution, the content of the polymer (A) is <NUM> - <NUM> mass %, preferably <NUM> - <NUM> mass %, more preferably <NUM> - <NUM> mass %, and further preferably <NUM> - <NUM> mass %. That is, it is one embodiment of the present invention that when the total mass of the substrate cleaning solution is made <NUM> mass %, the polymer (A) is <NUM> - <NUM> mass % based on this. That is, "compared with" can be reworded into "based on". Unless otherwise stated, the same is in the present specification.

The substrate cleaning solution used according to the present invention comprises an alkaline component (B). As a preferred embodiment, the alkaline component (B) remains in a film that has been formed from the substrate cleaning solution, and the alkaline component (B) dissolves in the remover (F) when the remover (F) peels off the film. For that, the boiling point of the alkaline component (B) at one atmospheric pressure is preferably <NUM> - <NUM>, more preferably <NUM> - <NUM>, and further preferably <NUM> - <NUM>.

The alkaline component (B) is represented by at least one of the formulae (B-<NUM>), (B-<NUM>), and (B-<NUM>).

(B-<NUM>) is represented by the following formula:
<CHM>
wherein,.

Although there is no intention to limit the present invention, preferred examples of (B-<NUM>) include N-benzylethanolamine, diethanolamine, monoethanolamine, <NUM>-(<NUM>-aminoethylamino)ethanol, <NUM>,<NUM>'-diaminodiphenylmethane, <NUM>-(butylamino)ethanol, <NUM>-anilinoethanol, triethanolamine, ethylenediamine, diethylenetriamine, tris(<NUM>-aminoethyl)amine, and tris[<NUM>-(dimethylamino)ethyl]amine.

(B-<NUM>) is represented by the following formula. <CHM>
wherein.

Although there is no intention to limit the present invention, preferred examples of (B-<NUM>) include N,N,N',N'-tetrakis(<NUM>-hydroxyethyl)ethylenediamine and N,N,N',N'-tetraethylethylenediamine.

(B-<NUM>) is <NUM>,<NUM>-diazabicyclo[<NUM>. <NUM>]octane, hexamethylenetetramine or a nitrogen-containing saturated hydrocarbon ring, comprising -NH-CH<NUM>-CH<NUM>- as a structural unit. As a preferred embodiment, the nitrogen- containing saturated hydrocarbon ring (B-<NUM>) has a ring structure by having repeatedly one type of structural unit. The nitrogen- containing saturated hydrocarbon ring (B-<NUM>) may be a cage-type three-dimensional structure or a planar ring structure.

Although there is no intention to limit the present invention, preferred examples of (B-<NUM>) having a planar ring structure include <NUM>,<NUM>,<NUM>,<NUM>-tetraazacyclododecane, and <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-hexaazacycloalkyloctadecane.

It is described for clarity that the substrate cleaning solution used according to the present invention may comprise one or more of the above-described preferred examples in combination as the alkaline component (B). For example, the alkaline component (B) may comprise both N-benzylethanolamine and diethanolamine. Also, the alkaline component (B) may comprise both N,N,N',N'-tetrakis(<NUM>-hydroxyethyl)ethylenediamine and <NUM>,<NUM>-diaza bicyclo [<NUM>. <NUM>] octane.

The molecular weight of the alkaline component (B) is preferably <NUM> - <NUM>, and more preferably <NUM> - <NUM>.

The alkaline component (B) can be obtained even by either synthesizing or purchasing. As a supplier, Sigma-Aldrich and Tokyo Chemical Industry Co. are mentioned.

In one embodiment of the present invention, the content of the alkaline component (B) is preferably <NUM> - <NUM> mass %, more preferably <NUM> - <NUM> mass %, and further preferably <NUM> - <NUM> mass %, based on the total mass of the polymer (A) in the substrate cleaning solution.

The substrate cleaning solution used according to the present invention comprises a solvent (C). Preferably, the solvent (C) comprises an organic solvent. As one embodiment of the present invention, the solvent (C) has volatility. Having volatility means to have higher volatility compared with water. For example, the boiling point of the solvent (C) at one atmospheric pressure is preferably <NUM> - <NUM>, more preferably <NUM> - <NUM>, further preferably <NUM> - <NUM>. It is also accepted that the solvent (C) contains a small amount of pure water. The content of the pure water contained in the solvent (C) is preferably <NUM> mass % or less, more preferably <NUM> mass % or less, and further preferably <NUM> mass % or less, and still more preferably <NUM> mass %, based on the total mass of the solvent (C). Containing no pure water (<NUM> mass %) is also a preferred embodiment of the present invention. In the present specification, pure water is preferably DIW.

As a preferred embodiment of the present invention, components (including additives) comprised in the substrate cleaning solution are soluble in the solvent (C). The substrate cleaning solution in this embodiment is considered to have good embedding properties or film uniformity.

The organic solvents include alcohols such as isopropanol (IPA); ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; ethylene glycol mono alkyl ether acetates such as ethylene glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether (PGME), propylene glycol monoethyl ether (PGEE); propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monoethyl ether acetate; lactic acid esters such as methyl lactate and ethyl lactate (EL); aromatic hydrocarbons such as toluene and xylene; ketones such as methyl ethyl ketone, <NUM>-heptanone and cyclohexanone; amides such as N,N-dimethylacetamide and N-methyl pyrrolidone; and lactones such as γ-butyrolactone. These organic solvents can be used alone or in any combination of any two or more of these.

As a preferred embodiment, the organic solvent contained in the solvent (C) is selected from IPA, PGME, PGEE, EL, PGMEA, and any combination of any of these. When the organic solvent is a combination of two, the volume ratio is preferably <NUM>:<NUM> - <NUM>:<NUM>, and more preferably <NUM>:<NUM> - <NUM>:<NUM>.

In one embodiment of the present invention, the content of the solvent (C) is <NUM> - <NUM> mass %, preferably <NUM> - <NUM> mass %, more preferably <NUM> - <NUM> mass %, further preferably <NUM> - <NUM> mass %, and still more preferably <NUM> - <NUM> mass %, based on the total mass of the substrate cleaning solution.

In one embodiment of the present invention, the substrate cleaning solution further comprises a crack accelerating component (D). The crack accelerating component (D) comprises hydrocarbon and further comprises a hydroxy group (-OH) and/or a carbonyl group (-C(=O)-). When the crack accelerating component (D) is polymer, one kind of the structural unit comprises hydrocarbon in each unit and further has a hydroxy group and/or a carbonyl group. The carbonyl group includes carboxylic acid (-COOH), aldehyde, ketone, ester, amide and enone, and carboxylic acid is preferred.

Although this is not intended to limit the scope of the invention and not to be bound by theory, it is considered that when the substrate cleaning solution is dried to form a film on the substrate and the crack accelerating component (D) remains in the film, the soluble solute (B) generates a portion to become a trigger that the film peels during peeling of the film by the remover (F). For this purpose, it is preferable that the crack accelerating component (B) has a higher solubility in the remover (F) than the polymer (A). As an embodiment in which the crack accelerating component (D) contains ketone as carbonyl group, a cyclic hydrocarbon is mentioned. Exemplified examples thereof include <NUM>,<NUM>-cyclohexanedione and <NUM>,<NUM>-cyclohexanedione.

In a more particular embodiment, the crack accelerating component (D) is represented by at least one of the formulae (D-<NUM>), (D-<NUM>), and (D-<NUM>):
(D-<NUM>) is a compound comprising <NUM> to <NUM> (preferably <NUM> to <NUM>) structural units, wherein the structural unit is represented by the formula (D-<NUM>)' and each structural unit is bonded via a linker L<NUM>,
<CHM>
wherein,.

Although there is no intention to limit the present invention, preferred examples of (D-<NUM>) include <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)propane, <NUM>,<NUM>'-methylenebis (<NUM>-methylphenol), <NUM>,<NUM>-bis[(<NUM>-hydroxy-<NUM>-methylphenyl) methyl]-<NUM>-methylphenol, <NUM>,<NUM>-cyclohexanediol, <NUM>,<NUM>'-dihydroxybiphenyl, <NUM>,<NUM>-naphthalenediol, <NUM>,<NUM>-di-tert-butyl hydroquinone and <NUM>,<NUM>,<NUM>,<NUM>-tetrakis(<NUM>-hydroxyphenyl)ethane. These may be obtained by polymerization or condensation.

<NUM>,<NUM>-bis[(<NUM>-hyd roxy-<NUM>-methylphenyl)methyl]-<NUM>-methylphenol is given as an example for explanation. In (D-<NUM>), the compound has three structural units (D-<NUM>)', and the structural units are linked by L<NUM> (methylene). nd1 = nd1' = <NUM>, and R<NUM> is methyl.

(D-<NUM>) is represented by the following formula. <CHM>
wherein,.

(D-<NUM>) is polymer comprising a structural unit represented by the formula (D-<NUM>)' and having the weight-average molecular weight (Mw) of <NUM> - <NUM>,<NUM>. The Mw is preferably <NUM> - <NUM>,<NUM>, and more preferably <NUM> - <NUM>,<NUM>. <CHM>
wherein,
R<NUM> is -H, -CH<NUM> or -COOH, preferably -H or -COOH. It is also accepted that one polymer (D-<NUM>) comprises two or more structural units each represented by (D-<NUM>)'.

Although there is no intention to limit the present invention, preferred examples of polymer (D-<NUM>) include polymer of acrylic acid, maleic acid, acrylic acid, or any combination of any of these. Polyacrylic acid, and copolymer of maleic acid and acrylic acid are further preferred examples.

In the case of copolymerization, it is preferably random copolymerization or block copolymerization, and more preferably random copolymerization.

Copolymer of maleic acid and acrylic acid is given as an example for explanation. The copolymer is contained in (D-<NUM>) and has two structural units (D-<NUM>)', and in one structural unit, R<NUM> is -H and in another structural unit, R<NUM> is -COOH.

It is described for clarity that the substrate cleaning solution used according to the present invention may comprise one or more of the above-described preferred examples in combination as the crack accelerating component (D). For example, the crack accelerating component (D) may comprise both <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)propane and <NUM>,<NUM>-dimethyl-<NUM>-octin-<NUM>,<NUM>-diol.

In one embodiment of the present invention, the molecular weight of the crack accelerating component (D) is <NUM> - <NUM>,<NUM>, preferably <NUM> - <NUM>,<NUM>, and more preferably <NUM> - <NUM>,<NUM>. When the crack accelerating component (D) is resin or polymer, the molecular weight represents weight-average molecular weight (Mw).

The crack accelerating component (D) can be obtained even by either synthesizing or purchasing. As a supplier, Sigma-Aldrich, Tokyo Chemical Industry Co. and Nippon Shokubai Co. are mentioned.

In one embodiment of the present invention, the content of the crack accelerating component (D) is preferably <NUM> - <NUM> mass %, more preferably <NUM> - <NUM> mass %, and further preferably <NUM> - <NUM> mass %, based on the total mass of the polymer (A) in the substrate cleaning solution.

The substrate cleaning solution used in the present invention may additionally comprise a further additive (E). In one embodiment of the present invention, the further additive (E) comprises a surfactant, an antibacterial agent, a germicide, an antiseptic, an antifungal agent, or a base (preferably, a surfactant), and it may comprise any combination of any of these.

In one embodiment of the present invention, the content of the further additive (E) (in the case of plural, the sum thereof) is <NUM> - <NUM> mass %, more preferably <NUM> - <NUM> mass %, further preferably <NUM> - <NUM> mass %, and still more preferably <NUM> - <NUM> mass %, based on the total mass of the polymer (A) in the substrate cleaning solution. Containing no further additive (<NUM> mass %) is also a preferred embodiment of the present invention.

In one embodiment of the present invention, as described above, the substrate cleaning solution is dripped on a substrate and dried to remove the solvent (C), and the polymer (A) forms a film. As a preferred embodiment, the alkaline component (B) and /or the crack accelerating component (D) remain in the film, and are not removed together with the solvent (C). The film is capable of holding particles present on the substrate, and the film is removed by the remover while holding.

The remover (F) is preferably neutral or mildly acidic. The pH of the remover (F) is preferably <NUM> - <NUM>, more preferably <NUM> - <NUM>, and still more preferably <NUM> - <NUM>. The measurement of pH is preferably carried out after being degassed, to avoid the influence of the dissolution of carbon dioxide gas in the air.

Preferably, the remover (F) comprises pure water. As mentioned above, the substrate cleaning solution comprises the alkaline component (B) which dissolves in the remover (F) and thus pH of the remover (F) is raised. Accordingly, most of the initial remover (F) may be pure water. The ratio of pure water contained in the solvent (F) is preferably <NUM> - <NUM> mass %, more preferably <NUM> - <NUM> mass %, further preferably <NUM> - <NUM> mass %, and still more preferably <NUM> - <NUM> mass %, based on the total mass of the solvent (F). As a preferred embodiment, the remover (F) consists only of pure water (<NUM> mass%).

Although this is not intended to limit the scope of the invention and not to be bound by theory, a state of cleaning the substrate according to the present invention is described using a schematic figure for the understanding of the present invention.

The substrate cleaning solution used in the embodiment of <FIG> is composed of a polymer (A), an alkaline component (B) and a solvent (C). (a) shows a state in which particles <NUM> are attached to the substrate <NUM>. The substrate cleaning solution used in the present invention is dripped on this substrate and dried, and the state in which the polymer forms a film (b) is shown by (b). In (b), the film becomes a particle holding layer <NUM>, and an alkaline component <NUM> remains in the film. Thereafter, a remover <NUM> is applied on the film, and the state in which the alkaline component has dissolved in the remover is shown by (c). Through such a dissolvement, traces <NUM> due to the elution of the alkaline component in the particle holding layer <NUM> are generated. It is considered that the pH of the remover in the vicinity of the film is raised by the elution of the alkaline component and the effect of peeling off the film from the substrate is enhanced. Further, the traces <NUM> become a trigger that the film peels. The state in which the cracks <NUM> grow from the traces <NUM> is shown by (d). The state in which the film parted by the growth of the cracks <NUM> is removed from the substrate while holding particles is shown by (e). The state of the substrate obtained by being cleaned is shown by (f).

The substrate cleaning solution used in the embodiment of <FIG> is composed of a polymer (A), an alkaline component (B), a solvent (C), and a crack accelerating component (D). <FIG> is different from <FIG> in further comprising the crack accelerating component. The process in the substrate cleaning is proceeded as same as is the case in <FIG>, except that a crack accelerating component <NUM> remains in the particle holding layer <NUM> in (b). Then, the crack accelerating component dissolves in the remover and traces <NUM> due to the elution of the crack accelerating component in the particle holding layer <NUM> are generated. The traces <NUM> enhance the action of peeling off the film from the substrate. The traces <NUM> itself can become a trigger that the film peels.

The method of the present invention is used to clean a substrate. For the cleaning of a substrate, an apparatus (for example, described in <CIT>) can be used. The present invention provides a method for manufacturing a cleaned substrate as one embodiment.

The method for cleaning a substrate is described below. In the following, numbers in parentheses indicate the order of steps. For example, when the steps (<NUM>-<NUM>), (<NUM>-<NUM>) and (<NUM>) are described, the order of the steps is as described above.

The above (<NUM>) is preferably carried out by dripping the substrate cleaning solution nearly at the center of the horizontally postured substrate through a nozzle or the like in an apparatus suitable for substrate cleaning. The dripping may be in the form of liquid column or dropping. At the time of the dripping, the substrate is rotated, for example, at <NUM> to several tens of rpm, so that the generation of dripping traces can be suppressed.

The dripping amount is preferably <NUM> - <NUM> cc. These conditions can be adjusted so that the substrate cleaning solution is uniformly applied and spread.

The removal of the solvent (C) described in the above (<NUM>) is preferably carried out by drying, preferably by spin-drying. The spin-dry is carried out at <NUM> - <NUM>,<NUM> rpm (more preferably <NUM> - <NUM>,<NUM> rpm, and further preferably <NUM> - <NUM>,<NUM> rpm) for preferably <NUM> - <NUM> seconds (more preferably <NUM> - <NUM> seconds, further preferably <NUM> - <NUM> seconds, and still more preferably <NUM> - <NUM> seconds). Accordingly, the solvent (C) can be dried while spreading the substrate cleaning solution over the entire surface of the substrate. Preferably, the substrate is a disk shape substrate having a diameter of <NUM> - <NUM> (more preferably <NUM> - <NUM>).

Making the film hold particles on the substrate referred in the above (<NUM>) means it is carried out by removing the solvent (C) referred in the above (<NUM>), whereby the polymer (A) forms a film and holds particles. That is, it can be said also that the above steps (<NUM>) and (<NUM>) occur continuously by one operation. Here, the removal of the solvent (C) referred in the above (<NUM>) accepts a state in which the solvent (C) slightly remains in the film. In one embodiment of the present invention, <NUM>% or more (preferably <NUM>% or more, and more preferably <NUM>% or more) of the solvent (C) is volatilized at the end of the above steps (<NUM>) and (<NUM>) and does not remain in the film.

As a preferred embodiment, solid components such as the alkaline component (B) and the crack accelerating component (D) remain in the film and not removed together with the solvent (C). Here, "remain in the film" means preferably to be in a state of coexistence in one film, but not to form separate layers.

The above steps (<NUM>) and/or (<NUM>) may be carried out while raising the temperature in the apparatus. It can be expected that raising of the temperature promotes the volatilization of the solvent (C) and the film formation of solid components such as the polymer (A). When the temperature is raised, it is preferably <NUM> - <NUM>.

In the above (<NUM>), a remover (F) is applied on the substrate to remove the film in which particles are held (particle holding layer). The application can be performed by dripping, spraying or dipping. The dripping may be performed so as to form a liquid pool (paddle) on the substrate or may be dripped continuously. In one embodiment of the present invention, the remover (F) is dripped at the center of the substrate while the substrate is rotating at <NUM> - <NUM> rpm.

When the remover (F) removes (for example, peels off) the particle holding layer, it is considered that the alkaline component (B) and/or the crack accelerating component (D) remained in the film generates a portion to become a trigger that the film peels. Accordingly, it is preferable that the alkaline component (B) and/or the crack accelerating component (D) have a higher solubility in the remover (F) than the polymer (A). The solubility can be evaluated by known methods. For example, it can be determined under the condition of <NUM> - <NUM> (more preferably <NUM>±<NUM>) by providing a flask charged with <NUM> ppm of the above (A) or (B) in pure water, covering the flask with a cap, shaking for <NUM> hours in a shaker, and confirming whether (A) or (B) is dissolved or not. For evaluation of solubility, the pure water can be changed to alkaline solution such as <NUM> mass % ammonia water.

It is a preferable embodiment of the present invention that the particle holding layer is removed from the substrate while holding particles without being completely dissolved by the remover (F). The particle holding layer is considered to be removed by, for example, becoming in a state of being finely cut by the "portion to become a trigger that the film peels".

In the method for cleaning a substrate according to the present invention, an embodiment additionally including at least one steps other than the above is also preferable. Such processes include those known in the substrate cleaning. For example, the following steps may be mentioned.

The substrate to be cleaned in the present invention include semiconductor wafers, glass substrates for liquid crystal display, glass substrates for organic EL display, glass substrates for plasma display, substrates for optical disk, substrates for magnetic disk, substrates for magneto-optical disk, glass substrates for photomask, substrates for solar cell, and the like. The substrate may be a non-processed substrate (for example, a bare wafer) or a processed substrate (for example, a patterned substrate). The substrate may be composed by laminating a plurality of layers. Preferably, the surface of the substrate is a semiconductor. The semiconductor may be composed of oxide, nitride, metal, and any combination of any of these. Further, the surface of the substrate is preferably selected from the group consisting of Si, Ge, SiGe, Si<NUM>N<NUM>, TaN, SiO<NUM>, TiOz, Al<NUM>O<NUM>, SiON, HfOz, T<NUM>O<NUM>, HfSiO<NUM>, Y<NUM>O<NUM>, GaN, TiN, TaN, Si<NUM>N<NUM>, NbN, Cu, Ta, W, Hf, and Al.

By further processing the substrate manufactured by the cleaning method according to the present invention, a device can be manufactured. Examples of the device include semiconductors, liquid crystal display devices, organic EL display devices, plasma display devices, and solar cell devices. A known method can be used for processing these. After device formation, if desired, the substrate can be cut into chips, connected to lead frame, and packaged with resin. One example of this packaged product is a semiconductor.

The present invention is described below with reference to examples. In addition, the embodiment of the present invention is not limited only to these examples.

A KrF resist composition (AZ DX-6270P, Merck Performance Materials K. , hereinafter referred to as MPM) is dripped on an <NUM>-inch Si substrate, and spin-coated on the substrate at <NUM> rpm. The substrate is soft-baked at <NUM> for <NUM> seconds. The resultant is exposed using KrF stepper (FPA-<NUM> EX5, Canon Inc. ) with <NUM> mJ/cm<NUM>, subjected to PEB (post exposure bake) for <NUM> seconds at <NUM> and developed with a developer (AZ MIF-<NUM>, MPM). Thereby, a line-and-space resist pattern having a pitch of <NUM> and a duty ratio of <NUM> : <NUM> is obtained. The substrate is etched with a dry etching apparatus (NE-5000N, ULVAC Inc. ) using the resist pattern as an etching mask. Thereafter, the substrate is cleaned with a stripper (AZ 400T, MPM), and the resist pattern and the resist residue are peeled off. Thereby, a patterned substrate having a pattern with a pitch of <NUM>, a duty ratio of <NUM> : <NUM>, and a line height of <NUM> is produced.

Particles are attached to the patterned substrate and the bare substrate described above.

Ultra-high purity colloidal silica (PL-<NUM>, Fuso Chemical Industry Co. , average primary particle size: <NUM>) is used as particles for experiment. <NUM> of the silica fine particle composition is dripped and applied by rotating at <NUM> rpm for <NUM> seconds. Thereafter, the solvent of the silica fine particle composition is spin-dried by rotating at <NUM> rpm for <NUM> seconds. Thereby, an evaluation substrate is obtained.

<NUM> of Novolak (Mw: about <NUM>,<NUM>, polymer (A)) is added to <NUM> of isopropanol (solvent (C)). The resultant is stirred with a stirrer for <NUM> hour to obtain a solution containing polymer (A) in a concentration of <NUM> mass %. Each <NUM> of diethanolamine (alkaline component (B)) and <NUM>,<NUM>-dimethyl-<NUM>-octin-<NUM>,<NUM>-diol (Tokyo Chemical Industry Co. , hereinafter referred to TCI, crack accelerating component (D)) are added to the solution. The resultant is stirred with a stirrer for <NUM> hour. This solution is filtered with Optimizer UPE (Nippon Entegris K. Thereby, a substrate cleaning solution comprising (A), (B), and (D) is obtained.

A substrate cleaning solution comprising (A) and (B) is obtained in the same manner except that the component (D) is not added.

A substrate cleaning solution comprising (A) and (D) is obtained in the same manner except that the component (B) is not added.

A substrate cleaning solution comprising (B) and (D) is obtained in the same manner except that the component (A) is not added.

Using Coater/Developer RF<NUM> (SOKUDO Co. ), <NUM> cc of each substrate cleaning solution is dripped on each evaluation substrate, and coating and drying are performed by rotating at <NUM>,<NUM> rpm for <NUM> seconds. While rotating the substrate at <NUM> rpm, DIW is dripped for <NUM> seconds, the whole substrate is covered with DIW, and this state is maintained for <NUM> seconds. By rotating the substrate at <NUM>,<NUM> rpm, the film is dried. When the film exists, the film is peeled off and removed by the rotation.

The amounts of residual particles on these substrates are compared. A bright field defect inspection system (UVision <NUM>, Applied Materials Inc. ) is used for the evaluation of the patterned substrate, and a dark field defect inspection system (LS-<NUM>, Hitachi High-Technologies Corporation) is used for the evaluation of the bare substrate.

The substrate cleaning solution comprising (A), (B), and (D) resulted in the fewest residual particles, and the substrate cleaning solution comprising (B) and (D) resulted in the most residual particles, on both patterned substrates and bare substrates. The substrate cleaning solution comprising (A) and (B) resulted in slightly more residual particles than the substrate cleaning solution comprising (A) and (D).

<NUM> of Novolak (Mw: about <NUM>,<NUM>, polymer (A)) is added to <NUM> of isopropanol (solvent (C)). The resultant is stirred with a stirrer for <NUM> hour to obtain a solution containing polymer (A) in a concentration of <NUM> mass %. Each <NUM> of N-benzylethanolamine (TCI, alkaline component (B)) and <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)propane (TCI, crack accelerating component (D)) are added to the solution. The resultant is stirred with a stirrer for <NUM> hour. This solution is filtered with Optimizer UPE (Nippon Entegris K. Thereby, Cleaning Solution <NUM> is obtained. This is indicated in Table <NUM>-<NUM>.

In the below Tables <NUM>-<NUM> and <NUM>-<NUM>, above mentioned Novolak, N-benzylethanolamine, and isopropanol are abbreviated as A1, B1, and D1, respectively. The number in parentheses in column (A) means the concentration (mass %) of the polymer (A) when the polymer (A) is added to the solvent (C). The number in parentheses in column (B) means the concentration (mass %) of the alkaline component (B) compared with the polymer (A) when the alkali component (B) is added to the solution. The number in parentheses in column (C) means the concentration (mass %) of the crack accelerating component (C) compared with the polymer (A) when the crack accelerating component (C) is added to the solution.

In the Tables <NUM>-<NUM> and <NUM>-<NUM>, the followings are abbreviated as follows:.

Cleaning Solutions <NUM> - <NUM> are prepared in the same manner as in Preparation Example <NUM> except that the polymer (A), the alkaline component (B), the solvent (C), the crack accelerating component (D) and the concentration are changed to those indicated in Tables <NUM>-<NUM> and <NUM>-<NUM>. This is indicated in Tables <NUM>-<NUM> and <NUM>-<NUM>.

N-benzylethanolamine (TCI, alkaline component (B)) and <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)propane (TCI, crack accelerating component (D)) is added to isopropanol (solvent (C)), so that each concentration is <NUM> mass %. The resultant is stirred with a stirrer for <NUM> hour. This solution is filtered with Optimizer UPE (Nippon Entegris K. Thereby, Comparative Cleaning Solution <NUM> is obtained. This is indicated in Table <NUM>-<NUM>.

Evaluation substrates prepared as described in the above-mentioned preparation of the evaluation substrate are used.

The state of application and the state of film removal are confirmed, the number of residual particles is counted and evaluated according to the following criteria. The evaluation results are indicated in Table <NUM>.

It is confirmed that compared with the substrate cleaned with Comparative Cleaning Solution <NUM>, the substrate cleaned with Cleaning Solutions <NUM>-<NUM> has less amount of residual particles.

A copper deposited substrate is obtained by depositing copper on a <NUM>-inch bare Si substrate using a thermal CVD method (temperature of substrate : <NUM>).

Claim 1:
A method for cleaning a substrate comprising
(<NUM>) dripping a substrate cleaning solution on a substrate;
(<NUM>) removing a solvent (C) in the substrate cleaning solution, and a polymer (A) forms a film;
(<NUM>) making the film to hold particles on the substrate; and
(<NUM>) applying a remover (F) on the substrate to remove the film in which the particles are held, wherein
the substrate cleaning solution comprising a polymer (A), an alkaline component (B), and a solvent (C), provided that the alkaline component (B) does not comprise ammonia;
wherein the alkaline component (B) is represented by at least one of the formulae (B-<NUM>), (B-<NUM>), and (B-<NUM>):
<CHM>
wherein,
L<NUM> is -CH<NUM>-, -CH<NUM>-CH<NUM>-, -CH<NUM>-CH<NUM>-CH<NUM>-, or the formula (B-<NUM>)':
<CHM>
where nb1 is <NUM> or <NUM>, nb2 is <NUM> or <NUM>, and nb1 + nb2 is not equal to <NUM>,
R<NUM> is -OH, -NH<NUM>, or -N(CH<NUM>)<NUM>,
L<NUM> is a single bond, -CH<NUM>-, -CH<NUM>-CH<NUM>-, -CH<NUM>-CH<NUM>-CH<NUM>-, or the above formula (B-<NUM>)',
R<NUM> is -H, -OH, -NH<NUM>, or -N(CH<NUM>)<NUM>,
L<NUM> is a single bond, -CH<NUM>-, -CH<NUM>-CH<NUM>-, -CH<NUM>-CH<NUM>-CH<NUM>-, or above formula (B-<NUM>)', and
R<NUM> is -H, -OH, -NH<NUM>, or -N(CH<NUM>)<NUM>;
<CHM>
wherein,
L<NUM> is -CH<NUM>-, -CH<NUM>-CH<NUM>-, or the above formula (B-<NUM>)',
L<NUM>, L<NUM>, L<NUM>, and L<NUM> are each independently -CH<NUM>- or -CH<NUM>-CH<NUM>-,
R<NUM>, R<NUM>, R<NUM>, and R<NUM> are each independently -OH or -CH<NUM>; and
(B-<NUM>) <NUM>,<NUM>-diazabicyclo[<NUM>.<NUM>]octane, hexamethylenetetramine or a nitrogen-containing saturated hydrocarbon ring,
comprising -NH-CH<NUM>-CH<NUM>- as a structural unit.