JP2001222118A - Rinsing solution for photolithography and method for treating substrate with same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rinsing solution used particularly for rinsing a substrate after the treatment of residue on ashing with a removing solution in the treatment of the substrate subjected to ashing after dry etching through a photoresist pattern formed on the substrate as a mask and a method for treating a substrate with the rinsing solution. SOLUTION: The rinsing solution for photolithography has pH 8-12 and contains a chelating agent and one or more saccharides.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rinsing solution for photolithography and a method for treating a substrate using the same. More specifically, in the processing of a substrate subjected to dry etching and ashing using a photoresist pattern provided on the substrate as a mask, a rinse used for cleaning (rinsing) the substrate after treating a residue after ashing with a stripping liquid. The present invention relates to a liquid and a method for treating a substrate using the liquid.
INDUSTRIAL APPLICATION This invention is used suitably for manufacture of semiconductor elements, such as IC and LSI, or a liquid crystal panel element.

[0002]

2. Description of the Related Art Semiconductor elements such as ICs and LSIs and liquid crystal panel elements are made of metal films deposited on a substrate by CVD or SiO _2.
A photoresist is uniformly coated on an insulating film such as a film, and selectively exposed and developed to form a photoresist pattern. Using this pattern as a mask, a metal film or a SiO ₂ film or the like deposited by the CVD method is used. After the substrate on which the insulating film is formed is selectively etched to form a fine circuit, an unnecessary photoresist layer is removed to manufacture the substrate.

Here, the metal film deposited by CVD includes aluminum (Al); aluminum-silicon (A).
1-Si), aluminum-silicon-copper (Al-Si-
Aluminum alloy (Al alloy) such as Cu); Titanium (T
i): Titanium alloys (Ti alloys) such as titanium nitride (TiN) and titanium tungsten (TiW); tantalum (Ta), tantalum nitride (TaN), tungsten (W), tungsten nitride (WN), copper (Cu) Such,
Various types have been used, and these are formed on a substrate in a single layer or a plurality of layers.

[0004] With the recent increase in the density of integrated circuits, dry etching capable of finer etching with higher density has become mainstream. In addition, plasma ashing is performed when unnecessary photoresist layers are removed after etching. By these etching and ashing processes,
The altered film residue remains in a square shape on the side and bottom of the pattern, or remains due to the adhesion of residues derived from other components, and metal deposition occurs when shaving the metal film during etching. Will occur. These are called "sidewalls" and the like, and if they are not completely removed, problems such as a decrease in the yield of semiconductor manufacturing occur.

[0005] These post-ash residues, such as altered film residues and metal depositions, can vary depending on the type of etching gas and ashing conditions, the type of metal formed on the substrate, the type of insulating film, the type of photoresist used, and the like. Each produces a different composition. The post-ashing residue has also become complicated due to the severe processing conditions in various processes and the diversification of metals, insulating films, and photoresists used in various processes accompanying various improvements in semiconductors in recent years.

[0006] Under such circumstances, as the photoresist-altered film removing solution or the treatment solution after ashing, any one selected from hydrofluoric acid or a salt of hydrofluoric acid and a base containing no metal ion is used. Known are a stripping solution containing at least one species (a hydrofluoric acid-based stripping solution) and a stripping solution containing a hydroxylamine and / or an alkanolamine (an amine-based stripping solution). These stripping solutions form a fine photoresist pattern and have a high ability to remove photoresist deteriorated films and metal depositions generated after etching and ashing, and various metal wirings, conductive metal films, and metal films deposited by CVD. It has the advantage of being superior in preventing corrosion of the film.On the other hand, in the case of using a hydrofluoric acid-based stripping solution, particularly in the rinsing process, corrosion of metal wiring is caused by pure water or an aqueous component in the rinsing solution. There is a problem that it is easy.

Heretofore, as a rinsing liquid and a rinsing method in photolithography processing, generally, pure water alone, alcohols, a method of using pure water and alcohols in combination, and the like have been used.

[0008] In addition to the above, for example, see
Japanese Patent Publication No. 213612 proposes a cleaning solution composed of water containing peroxide. Also, Japanese Patent Application Laid-Open No. 7-2971
No. 58 discloses a substrate or an organic-inorganic contaminant containing a basic aqueous solution of a metal-free ion, a nonionic surfactant, and a pH-lowering chemical component for lowering or adjusting the pH of a cleaning solution to a range of about 8 to 10. Cleaning solutions have been proposed.

However, in the rinsing step after using the above-described stripping solution as the stripping solution after ashing, when the cleaning solution described in the above publication is used, or when the above-mentioned conventional pure water or alcohol is used, sufficient cleaning is not performed. It is difficult to suppress the corrosion of the substrate (metal wiring or the like) to a satisfactory extent and to suppress the precipitation of the residue.

[0010] As a rinsing liquid used after the hydrofluoric acid-based stripping liquid processing, a rinsing liquid containing a lower alkylene glycol and another water-soluble organic solvent (JP-A-10-239866) is used in the present application. Although proposed by humans, the present invention is intended to further prevent corrosion of a substrate (metal wiring or the like) and precipitation of a residue.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and particularly, in the processing of a substrate which has been subjected to dry etching and ashing using a photoresist pattern provided on the substrate as a mask, the ashing after the ashing is performed. An object of the present invention is to provide a rinse liquid used for cleaning (rinsing) a substrate after treating a residue with a stripping liquid, and a method for treating a substrate using the rinse liquid. ADVANTAGE OF THE INVENTION According to this invention, in the rinsing process of the board | substrate after a peeling process, there is no metal wiring pattern deformation | transformation, a deformation | transformation, etc., and excellent prevention of a board | substrate (metal wiring etc.) corrosion prevention and prevention of precipitation of a residue can be achieved more effectively. it can.

[0012]

In order to solve the above-mentioned problems, the present invention provides a method of etching a substrate using a photoresist pattern provided on the substrate as a mask, ashing, and subsequently removing a residue after the ashing by a stripping solution. A rinsing solution for use in a rinsing treatment after the treatment, wherein the rinsing solution has a pH of 8 to 12, and contains at least one selected from a chelating agent and a saccharide A rinsing liquid for photolithography is provided.

The present invention also provides (I) a step of selectively exposing and developing a photoresist layer provided on a substrate having a metal layer to form a photoresist pattern, and (II) etching the substrate using the photoresist pattern as a mask. (III) ashing the photoresist pattern, (IV) treating the substrate after the ashing process with a remover to remove the ashing residue, and (V) performing the above treatment. Thereafter, a step of bringing the substrate into contact with a rinsing liquid to carry out a rinsing treatment, and (VI) after the treatment,
Further, the present invention provides a method for treating a substrate, comprising a step of rinsing the substrate with water, wherein the rinsing liquid of the present invention is used in the step (V).

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The rinsing liquid for photolithography of the present invention comprises:
It contains at least one selected from a chelating agent and a saccharide as essential components.

As the chelating agent, at least one selected from aromatic hydroxy compounds and benzotriazole and its derivatives is preferably used.

Examples of the aromatic hydroxy compound include pyrocatechol (= 1,2-dihydroxybenzene), resorcinol, hydroquinone, 4-methylpyrocatechol,
4-methylresorcinol, 5-methylresorcinol, 2-methylhydroquinone, 3- (8-pentadecenyl) -1,2-benzenediol, 2,5-dimethylresorcinol, 4,6-dimethylresorcinol, 2,
Dihydric phenols such as 5-dimethylhydroquinone and 2-isopropyl-5-methylhydroquinone; pyrogallol;
Gallic acid, 1,2,4-benzenetriol, 1,3
Polyhydric phenols such as 5-benzenetriol, 2,4,6-trihydroxytoluene, 2,4,6-trihydroxy-m-xylene, 2,4,6-trihydroxymesitylene, benzenetetraol and benzenehexaol Benzyl alcohol such as salicyl alcohol, p-hydroxybenzyl alcohol, 4-hydroxy-3-methoxybenzyl alcohol, and 4-hydroxy-3-methoxycinnamyl alcohol. Among them, an aromatic hydroxy compound in which two or more hydroxyl groups are substituted in the ortho positional relationship is preferably used. Such compounds include pyrocatechol, pyrogallol, 1,
2,4-benzenetriol and the like are preferably used.

Benzotriazole and its derivatives are represented by the following general formula (II):

[0019]

Embedded image [Wherein Q is a hydrogen atom, a hydroxyl group, or a carbon atom having 1 to 1
10 substituted or unsubstituted hydrocarbon groups, aryl groups, or

[0020]

Embedded image (Wherein, R ⁵ represents an alkyl group having 1 to 6 carbon atoms; R ⁶ and R ⁷ each independently represent a hydrogen atom, a hydroxyl group,
Or a hydroxyalkyl group or an alkoxyalkyl group having 1 to 6 carbon atoms).
R ³ and R ⁴ each independently represent a hydrogen atom or a carbon atom having 1 to 1 carbon atoms.
10 substituted or unsubstituted hydrocarbon groups, carboxyl groups, amino groups, hydroxyl groups, cyano groups, formyl groups, sulfonylalkyl groups, or sulfo groups].

"Hydrocarbon group" is an organic group comprising a carbon atom and a hydrogen atom. In the present invention, the group Q,
In each definition of R ³ and R ⁴ , the hydrocarbon group may be either an aromatic hydrocarbon group or an aliphatic hydrocarbon group, and may have a saturated or unsaturated bond. Any of branched chains may be used. Examples of the substituted hydrocarbon group include a hydroxyalkyl group and an alkoxylalkyl group.

When copper (Cu) is used as the metal wiring, Q in the general formula (II) is particularly preferably a group represented by the above formula (3). Among them, in Chemical Formula 3, R ⁶ and R ⁷
It is preferable to independently select a hydroxyalkyl group or an alkoxyalkyl group having 1 to 6 carbon atoms. When at least one of R ⁶ and R ⁷ is an alkyl group having 1 to 6 carbon atoms, the properties of benzotriazole and a derivative thereof having such a composition are as follows:
Although it becomes poor in water solubility, it is preferably used when other components that dissolve the compound are present in the stripping solution.

Specific examples of benzotriazole and its derivatives include, for example, benzotriazole, 5,6
-Dimethylbenzotriazole, 1-hydroxybenzotriazole, 1-methylbenzotriazole, 1-aminobenzotriazole, 1-phenylbenzotriazole, 1-hydroxymethylbenzotriazole, 1-
Methyl benzotriazolecarboxylate, 5-benzotriazolecarboxylic acid, 1-methoxy-benzotriazole, 1- (2,2-dihydroxyethyl) -benzotriazole, 1- (2,3-dihydroxypropyl) benzotriazole, or ilgamet 2,2 ′-{[(4-methyl-1H-benzotriazol-1-yl) methyl] imino} bisethanol, commercially available as a series from Ciba Specialty Chemicals,
2,2 ′-{[(5-methyl-1H-benzotriazol-1-yl) methyl] imino} bisethanol, 2,
2 ′-{[(4-methyl-1H-benzotriazole-
1-yl) methyl] imino} bisethane, or 2,
2 ′-{[(4-methyl-1H-benzotriazole-
1-yl) methyl] imino} bispropane. Among these, benzotriazole, 1
-(2,3-dihydroxypropyl) -benzotriazole, 2,2 ′-{[(4-methyl-1H-benzotriazol-1-yl) methyl] imino} bisethanol, 2,2 ′-} [(5 -Methyl-1H-benzotriazol-1-yl) methyl] iminodibisethanol is preferably used from the viewpoint of the anticorrosion effect of Al alloy wiring and Cu wiring. These compounds are particularly effective for preventing corrosion of a substrate on which pure Cu wiring is formed.

One or more chelating agents can be used.

Examples of the saccharide include so-called saccharides generally represented by C _n (H ₂ O) _m , and sugar alcohols obtained by reducing the carbonyl group of these saccharides.
Sorbitol, mannitol, xylitol, erythritol, D-threitol, L-arabinitol, ribitol, D-glucitol, galactitol, L-rhamnitol, sucrose, starch and the like. Among them, xylitol and D-sorbitol are preferred. One or more saccharides can be used.

The above-mentioned chelating agent and saccharide are mainly for obtaining an anticorrosive effect, and the total amount thereof is preferably 0.1 to 10% by weight, particularly preferably 0.5 to 10% by weight in the rinsing solution of the present invention. 5% by weight.

The rinse solution of the present invention is an alkaline aqueous solution having a pH in the range of 8 to 12. Specifically, it is preferable to contain at least one selected from hydroxylamines and amines having an acid dissociation constant (pKa) of 7.5 to 13 in an aqueous solution at 25 ° C.

Hydroxylamines are represented by the following general formula (I)

[0029]

Embedded image (Wherein, R ¹ and R ² each independently represent a hydrogen atom or a lower alkyl group having 1 to 6 carbon atoms).

Here, the lower alkyl group having 1 to 6 carbon atoms includes a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group,
Examples include tert-butyl, pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, isohexyl, 3-methylpentyl, 2,2-dimethylbutyl, and 2,3-dimethylbutyl. Is done. R ¹ and R ² may be the same or different.

Specific examples of the above-mentioned hydroxylamines include hydroxylamine (NH ₂ OH), N-methylhydroxylamine, N, N-dimethylhydroxylamine, N, N-diethylhydroxylamine and the like. Among them, hydroxylamine (NH ₂ OH) is particularly preferably used. One or more hydroxylamines can be used.

The acid dissociation constant (pK) in an aqueous solution at 25 ° C.
Examples of the amines in which a) is 7.5 to 13 include monoethanolamine, diethanolamine, triethanolamine, 2- (2-aminoethoxy) ethanol,
N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-dibutylethanolamine,
Alkanolamines such as N-methylethanolamine, N-ethylethanolamine, N-butylethanolamine, N-methyldiethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine; diethylenetriamine, triethylenetetramine, propylenediamine; , N-diethylethylenediamine, N, N′-diethylethylenediamine, 1,4-butanediamine, N-ethyl-ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 1,6-hexanediamine and the like Alkylene polyamines; aliphatic alkyls such as 2-ethyl-hexylamine, dioctylamine, tributylamine, tripropylamine, triallylamine, heptylamine and cyclohexylamine; Amines; aromatic amines such as benzylamine and diphenylamine; and cyclic amines such as piperazine, N-methyl-piperazine, methyl-piperazine, and hydroxylethylpiperazine. Among them, monoethanolamine, triethanolamine, 2
-(2-Aminoethoxy) ethanol, diethylenetriamine, triethylenetetramine, cyclohexylamine, piperazine and the like are particularly preferred. These amines are 1
Species or two or more can be used.

Further, among the above-mentioned amines, when triethanolamine is used in combination with other amine compounds, the effect of preventing corrosion of Al and Al alloy wiring is preferably high. Examples of the amine compound used in combination with triethanolamine include hydroxylamines and amines having the above-mentioned pKa value.
In particular, alkanolamines (excluding triethanolamine) are preferably used. In this case, the mixing ratio of triethanolamine and other amine compounds is 10:
It is preferable to set it to about 0.1 to 10: 5 (weight ratio).

The total amount of hydroxylamines and amines varies depending on the basicity of each amine, but is preferably from 1 to 70% by weight, particularly preferably from 5 to 30% by weight in the rinsing solution of the present invention.

In order to improve the anticorrosion property, ammonia water may be added as required. The amount of the aqueous ammonia is preferably 0.1 to 10% by weight, particularly 0.5 to 5% by weight in the rinsing liquid of the present invention.

Further, in order to improve the permeability of the rinsing liquid, the following general formula (III) is optionally used.

[0037]

Embedded image (Wherein, R ⁸ represents an alkyl group having 6 to 20 carbon atoms), and at least one compound selected from an N-alkyl-2-pyrrolidone and an acetylene alcohol / alkylene oxide adduct. You may mix.

N-alkyl-2-pyrrolidone and acetylene alcohol / alkylene oxide adduct are substances known per se as surfactants.

Specific examples of the N-alkyl-2-pyrrolidone represented by the general formula (III) include N-hexyl-
2-pyrrolidone, N-heptyl-2-pyrrolidone, N-
Octyl-2-pyrrolidone, N-nonyl-2-pyrrolidone, N-decyl-2-pyrrolidone, N-undecyl-2
-Pyrrolidone, N-dodecyl-2-pyrrolidone, N-tridecyl-2-pyrrolidone, N-tetradecyl-2-pyrrolidone, N-pentadecyl-2-pyrrolidone, N-hexadecyl-2-pyrrolidone, N-heptadecyl-2-
Pyrrolidone, N-octadecyl-2-pyrrolidone and the like. Among them, N-octyl-2-pyrrolidone, N-
Dodecyl-2-pyrrolidone is referred to as "SURFADONE LP10
0 "and" SURFADONE LP300 "(both are all manufactured by ASP Japan), and are suitably used.

In the acetylene alcohol / alkylene oxide adduct, the acetylene alcohol forming the adduct is represented by the following general formula (IV):

[0041]

Embedded image (However, R ⁹ is a hydrogen atom or

[0042]

Embedded image Wherein R ¹⁰ , R ¹¹ , R ¹² and R ¹³ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms). Where the number of carbon atoms is 1
As the alkyl group of 6, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a se
c-butyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, tert-pentyl group,
Hexyl group, isohexyl group, 3-methylpentyl group,
Examples thereof include a 2,2-dimethylbutyl group and a 2,3-dimethylbutyl group.

The acetylene alcohol is, for example, “Surfinol” or “Olfin” (both of which are Air Pr
oduct and Chemicals Inc.) and are suitably used. Among them, “Surfinol 104”, “Surfinol 82” or a mixture thereof is most preferably used in view of its physical properties. In addition, “Olfin B”, “Olfin P”, “Olfin Y” and the like can be used.

As the alkylene oxide added to the acetylene alcohol, ethylene oxide, propylene oxide or a mixture thereof is preferably used.

In the present invention, an acetylene alcohol / alkylene oxide adduct is represented by the following general formula (V):

[0046]

Embedded image (However, R ¹⁴ is a hydrogen atom or

[0047]

Embedded image Wherein R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms). Where (n + m) is 1
It represents an integer of up to 30 and the characteristics such as solubility in water and surface tension slightly change depending on the number of ethylene oxides added.

The acetylene alcohol / alkylene oxide adduct is referred to as “Surfinol” (Air Product and Chlorine).
emicals Inc.), or “acetyleneol” (manufactured by Kawaken Fine Chemicals Co., Ltd.) and the like, and are suitably used. Above all, considering the change in properties such as solubility in water and surface tension depending on the number of added ethylene oxides, "Surfinol 440"
(N + m = 3.5), “Surfinol 465” (n + m
m = 10), “Surfinol 485” (n + m = 3)
0), “acetylenol EL” (n + m = 4), “acetylenol EH” (n + m = 10), or a mixture thereof is suitably used. In particular, acetylenol E
L "and" acetylenol EH "are preferably used. Among them, a mixture of "acetylenol EL" and "acetylenol EH" in a ratio of 2: 8 to 4: 6 (weight ratio) is particularly preferably used.

In the rinsing solution of the present invention, the compounding amount of the compound which can be added for improving the permeability of the rinsing solution is 0.1.
It is preferably from 0.01 to 1% by weight, particularly preferably from 0.015 to 0.5% by weight.
% By weight.

The rinsing liquid of the present invention is used for rinsing after etching the substrate using the photoresist pattern provided on the substrate as a mask, ashing, and then treating the residue after the ashing with a stripping solution. It is.

As the stripping solution for stripping and removing the residue after the ashing, hydroxylamines and / or
Alternatively, an amine-based stripping solution containing alkanolamines, or a hydrofluoric acid-based stripping solution containing one or more selected from hydrofluoric acid or a salt of hydrofluoric acid and a base containing no metal ion Liquid or the like is used.

In the above-mentioned salt of hydrofluoric acid and a base not containing a metal ion, the base not containing a metal ion includes hydroxylamines, primary, secondary and tertiary salts.
Organic amines such as lower aliphatic amines, alicyclic amines, aromatic amines, and heterocyclic amines, aqueous ammonia, and lower alkyl quaternary ammonium bases are preferably used.

Specific examples of hydroxylamines include hydroxylamine (NH ₂ OH), N-methylhydroxylamine, N, N-dimethylhydroxylamine, N, N-diethylhydroxylamine and the like.

As the primary aliphatic amine, specifically, monoethanolamine, ethylenediamine, 2- (2-
Aminoethylamino) ethanol and the like are exemplified.

Specific examples of the secondary aliphatic amine include diethanolamine, dipropylamine, 2-ethylaminoethanol and the like.

Specific examples of the tertiary aliphatic amine include dimethylaminoethanol and ethyldiethanolamine.

Specific examples of the alicyclic amine include cyclohexylamine and dicyclohexylamine.

Specific examples of the aromatic amine include benzylamine, dibenzylamine, N-methylbenzylamine and the like.

Specific examples of the heterocyclic amine include pyrrole, pyrrolidine, pyrrolidone, pyridine, morpholine, pyrazine, piperidine, N-hydroxyethylpiperidine, oxazole, thiazole and the like.

As the lower alkyl quaternary ammonium base, specifically, tetramethylammonium hydroxide (= TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, trimethylethylammonium hydroxide, (2-hydroxyethyl) Trimethylammonium hydroxide,
Examples thereof include (2-hydroxyethyl) triethylammonium hydroxide, (2-hydroxyethyl) tripropylammonium hydroxide, and (1-hydroxypropyl) trimethylammonium hydroxide.

Among them, ammonia water, monoethanolamine, tetramethylammonium hydroxide, (2-
(Hydroxyethyl) trimethylammonium hydroxide is preferably used because it is easily available and excellent in safety.

As the base containing no metal ion, one kind may be used alone, or two or more kinds may be used in combination.

The salt of a metal ion-free base and hydrofluoric acid is prepared by adding a metal ion-free base to a commercially available hydrofluoric acid having a concentration of 50 to 60% and a pH of 5 to 60%.
It can be manufactured by adding so as to be about 8 or less. As such a salt, ammonium fluoride is most preferably used.

Such a hydrofluoric acid-based stripping solution (treatment solution)
Specific examples of the above include, for example, (a) a salt of hydrofluoric acid and a base containing no metal ion, (b) a water-soluble organic solvent described in JP-A-9-197681, which was previously filed by the present applicant; And (c) a treatment solution after ashing prepared by mixing water, but the invention is not limited thereto.

Here, the component (a) is as described above.

As the above component (b), dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3
-Dimethyl-2-imidazolidinone, ethylene glycol, and at least one selected from diethylene glycol monobutyl ether are exemplified.

In the above-mentioned fluoric acid-based stripping solution, the component amounts of the components (a) are preferably from 0.2 to 30% by weight, the component (b) is from 30 to 80% by weight, and the remainder is the component (c). It is.

Incidentally, hydrofluoric acid may be further blended.

In this case, the compounding amount of each component of the fluoric acid-based stripping solution is preferably such that component (a) is 0.2 to 30% by weight,
The component (b) is blended at 30 to 80% by weight, hydrofluoric acid is added at an upper limit of 0.5% by weight, and the remainder is the component (c).

The rinsing solution of the present invention can be advantageously used for photoresists that can be developed with an aqueous alkaline solution, including negative and positive photoresists. Examples of such a photoresist include (i) a positive photoresist containing a naphthoquinonediazide compound and a novolak resin, (ii) a compound which generates an acid upon exposure, a compound which is decomposed by an acid to increase solubility in an aqueous alkali solution, and an alkali-soluble compound. A positive photoresist containing a resin, (iii) a compound which generates an acid upon exposure, a positive photoresist containing an alkali-soluble resin having a group which is decomposed by an acid and has increased solubility in an alkaline aqueous solution, and (iv) light Acid-generating compounds, such as a negative photoresist containing a crosslinking agent and an alkali-soluble resin, and the like,
It is not limited to these.

The method for treating a substrate according to the present invention comprises the steps of: (I) selectively exposing and developing a photoresist layer provided on a substrate having a metal layer to provide a photoresist pattern;
I) a step of etching a substrate using the photoresist pattern as a mask to form a metal wiring pattern; (III)
Ashing the photoresist pattern, (IV) treating the substrate after the ashing process with a remover to remove the residue after the ashing, and (V) rinsing by contacting the substrate with a rinse solution after the above treatment And (VI) a rinsing treatment of the substrate with water after the treatment, wherein the rinsing liquid of the present invention is used.

Specifically, a photoresist layer is formed on a substrate such as a silicon wafer or glass. An insulating film such as a conductive metal film / metal oxide film or an SiO ₂ film may be formed on the substrate by vapor deposition or the like, if desired. As the conductive metal film / metal oxide film, aluminum (A
l); Aluminum alloys (Al alloys) such as aluminum-silicon (Al-Si) and aluminum-silicon-copper (Al-Si-Cu); titanium (Ti); titanium nitride (TiN), titanium tungsten (TiW) Titanium (Ta), tantalum nitride (TaN), tungsten (W), tungsten nitride (WN), copper (Cu), etc. are used. Formed on top. In particular, Al; Al-S
i, Al alloys such as Al-Si-Cu; Ti; TiN, T
In the case of a Ti alloy such as iW; Cu, when ashing is performed, a residue adheres and deposition is likely to occur. Therefore, a hydrofluoric acid-based stripping solution is particularly preferably used for stripping and removal.

Next, a photoresist pattern is formed.
Exposure and development conditions can be appropriately selected depending on the photoresist used depending on the purpose. Exposure is, for example, ultraviolet light, far ultraviolet light, excimer laser, X-ray, a light source that emits active light such as an electron beam, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, etc., through a desired mask pattern. Expose the photoresist layer or irradiate the photoresist layer while scanning with an electron beam. afterwards,
A post-exposure bake (post-exposure bake) is performed as necessary.

Next, pattern development is performed using a photoresist developing solution to obtain a predetermined photoresist pattern. The developing method is not particularly limited. For example, after immersing the substrate coated with the photoresist in the developing solution for a certain period of time, immersion development in which the substrate is washed with water and dried, the developing solution is dropped on the surface of the coated photoresist. Various developments can be performed according to the purpose, such as paddle development in which the sample is left standing for a certain period of time and then washing and drying, and spray development in which a developing solution is sprayed on the photoresist surface and then washed and dried.

Next, using the formed photoresist pattern as a mask, the conductive metal film and the insulating film are selectively etched by dry etching or the like to form a fine circuit, and the unnecessary photoresist layer is removed by plasma ashing. . At this time, resist residue after ashing and metal deposition generated during etching of the metal film adhere and remain on the substrate surface as residue.

These residues are brought into contact with a stripping solution to remove the residues on the substrate.

Next, after the peeling and removing treatment, the substrate is brought into contact with the above-mentioned rinsing liquid of the present invention to carry out rinsing treatment. The rinsing method is
It can be performed by a known method. The rinsing liquid contact time may be a time necessary for cleaning and removing the stripping liquid from the substrate.

Subsequently, the substrate is further rinsed with water, and the rinse solution of the present invention is washed and removed from the substrate.

In particular, the rinsing liquid of the present invention can more remarkably show the anticorrosion property and the rinsing effect of the substrate in the rinsing treatment when a hydrofluoric acid-based stripping liquid is used as the stripping liquid. For example, in the case of an SiO ₂ substrate provided with an Al—Cu layer, a photoresist pattern is formed thereon, and the substrate is etched using the photoresist pattern as a mask to form a metal wiring pattern (Al—Cu pattern), and then ashing is performed. When the treatment is performed, Al-Cu-based sidewalls and Si-based sidewalls are generated as metal deposition on both sides of the Al-Cu pattern as residues after ashing.

After the ashing, when the residue is removed with a hydrofluoric acid-based stripping solution, the removal rate of each component forming the residue is different. When the hydrofluoric acid-based stripping solution is used, each component constituting the residue is removed. The magnitude of the component peeling removal rate (the magnitude of the solubility; “etch rate”) is in the order of Si>Cu> Al. As a result, the Si-based sidewall can be effectively peeled and removed, but the Al-Cu-based sidewall remains without being completely removed.

After the treatment with the stripping solution, rinsing directly with pure water as in the conventional example, the hydrofluoric acid in the hydrofluoric acid-based stripping solution is mixed with the pure water, whereby the etching rate of Al is rapidly increased. Although the Al-based sidewall can be removed, the etch rate of Cu rapidly decreases. Due to the difference in the etch rate (that is, the solubility of the metal), precipitation of Cu occurs on the surface of the Al-Cu metal wiring, and Al dissolves, resulting in thinning of the Al-Cu metal wiring.

On the other hand, by performing the rinsing treatment with the rinsing solution of the present invention between the stripping treatment with the hydrofluoric acid-based stripping solution and the pure water rinsing treatment, it is possible to prevent the etch rate of Al from increasing. , Cu precipitation and Al dissolution can be suppressed.

This is because the ratio (% by weight) of the hydrofluoric acid stripping solution in the mixed state of the hydrofluoric acid stripping solution and the rinsing solution is reduced by the rinsing treatment (washing and removing), and the case of pure water rinsing is different from that of the present invention. In the case of the rinse solution, the pH in the system
It seems that the change in value is due to a contrasting movement. That is, in the case of pure water rinsing, the pH value in the system gradually shifts to the acidic side, while in the case of the rinsing liquid of the present invention, the pH in the system shifts further to the alkaline side. It is considered that this difference in the pH change greatly affects the etch rate of each component, particularly, metals such as Al and Cu as described above. It is considered that the difference between these etch rates appears as a difference in the effect of maintaining the pattern of the Al-Cu wiring (metal wiring) and preventing the deposition of Cu.

By the rinsing liquid of the present invention and the method of processing a substrate of the present invention, in the cleaning (rinsing) of the substrate after the ashing residue is peeled and removed with a peeling liquid, the metal wiring pattern is not distorted or deformed. Excellent prevention of corrosion of substrates (metal wiring and the like) and precipitation of residues can be achieved.

[0085]

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. In addition, the blending amount is% by weight unless otherwise specified.
It is.

(Examples 1 to 11 and Comparative Examples 1 and 2) A positive type photoresist made of novolak resin was formed on a silicon wafer having an SiO ₂ layer formed by plasma CVD and an Al—Cu layer formed thereon. A certain THMR
-IP3300 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied by spinner, and prebaked at 90 ° C. for 90 seconds to form a 0.2 μm-thick photoresist layer. This photoresist layer is exposed through a mask pattern using NSR2005i10D (manufactured by Nikon Corporation), and 2.38% by weight of tetramethylammonium hydroxide (TMAH)
Was used to obtain a photoresist pattern. Next, post-baking was performed at 120 ° C. for 90 seconds.

Next, the etching apparatus T
Using SS-6000 (manufactured by Tokyo Ohka Kogyo Co., Ltd.), etching was performed for 168 seconds at a pressure of 0.67 Pa and a stage temperature of 20 ° C. using a mixed gas of chlorine and boron trichloride as an etchant. Using a mixed gas, a pressure of 2.66 Pa and a stage temperature of 20 ° C.
After-corrosion treatment (treatment for removing chlorine atoms) was performed for 0 seconds. Next, the ashing device TCA-3822
Ashing of the photoresist pattern was performed at a pressure of 0.16 Pa and a stage temperature of 220 ° C. for 40 seconds (manufactured by Tokyo Ohka Kogyo Co., Ltd.).

The treated substrate was immersed in SST-A2 (manufactured by Tokyo Ohka Kogyo Co., Ltd.), which is a hydrofluoric acid-based stripper, at 23 ° C. for 5 to 20 minutes to remove the deteriorated photoresist film and The metal deposition was removed. The treated substrate is rinsed using a rinsing liquid shown in Table 1, and further rinsed with pure water, and the silicon wafer is subjected to SEM (scanning electron microscope) to precipitate Cu (rinse effect of the substrate). And the corrosion of the Al—Cu layer (corrosion prevention effect of the substrate) were evaluated according to the following criteria. Tables 1 and 2 show the results.
Shown in The pH was measured with a pH meter (liquid temperature 23 ° C.).

(Examples 12 and 13) An etching stopper layer made of a SiN layer was provided on a substrate on which a Cu wiring was formed, and an interlayer insulating layer made of an organic SOG film was further formed thereon to form a naphthoquinone diazide compound. TH, a positive photoresist composition comprising a resin and a novolak resin
MR-iP3300 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied by a spinner, and pre-baked at 90 ° C. for 90 seconds.
A photoresist layer having a thickness of 2.0 μm was formed.

This photoresist layer was coated with NSR-2005i
Exposure was performed using a 10D (manufactured by Nikon Corporation) through a mask pattern, and developed with a 2.38% by weight aqueous solution of TMAH (tetramethylammonium hydroxide) to form a photoresist pattern (hole space 0.5 μm). . Next, post-baking was performed at 120 ° C. for 90 seconds.

Next, the substrate having the photoresist pattern formed under the above conditions was subjected to dry etching. The etching process is stopped with the SiN layer remaining, followed by ashing using an ashing device TCA-38228 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) to remove the photoresist layer, followed by dry etching. , SiN
The layer was completely removed.

The treated substrate was immersed in SST-A2 (manufactured by Tokyo Ohka Kogyo Co., Ltd.), a hydrofluoric acid-based stripper, at 23 ° C. for 5 to 20 minutes to remove the deteriorated photoresist film and The metal deposition was removed. The treated substrate is rinsed using a rinse solution shown in Table 1, and further rinsed with pure water. The silicon wafer is subjected to SEM (scanning electron microscope) to precipitate Cu (rinse effect of the substrate), The corrosion of the Cu layer (corrosion prevention effect of the substrate) was evaluated according to the following criteria. Table 2 shows the results. The pH was measured with a pH meter (liquid temperature 23 ° C.).

[Precipitation of Cu] (Evaluation) A: Almost no precipitation of Cu was observed. B: Deposition of Cu was observed.

[Corrosion State of Al-Cu Layer and Cu Layer] (Evaluation) A: Al-Cu layer and Cu layer hardly corroded B: Al-Cu layer and Cu layer slightly corroded C observed: Corrosion of Al-Cu layer and Cu layer was considerably observed.

[0095]

[Table 1]

[0096]

[Table 2]

In Example 13, the "benzotriazole derivative" was 2,2 '-{[(4-methyl-1H
-Benzotriazol-1-yl) methyl] iminodibisethanol.

[0098]

As described above in detail, according to the present invention, in the processing of a substrate subjected to dry etching and ashing using a photoresist pattern provided on the substrate as a mask, a residue after ashing is treated with a stripping solution. It is possible to provide a rinsing liquid used for cleaning (rinsing) the substrate after the rinsing and a method for treating the substrate using the rinsing liquid. ADVANTAGE OF THE INVENTION According to this invention, in the rinsing process of the board | substrate after a stripping liquid process, there is no metal wiring pattern deformation | transformation, a deformation | transformation, etc., and excellent prevention of board | substrate (metal wiring etc.) corrosion prevention and prevention of precipitation of a residue can be aimed at.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/306 H01L 21/30 572A 21/308 21/302 N 21/306 DF Term (Reference) 2H096 AA25 CA05 GA18 HA11 HA30 LA03 LA30 4G059 AA08 AB01 AB07 AB11 AC30 5F004 AA09 CA04 FA00 5F043 AA37 BB27 CC16 DD10 DD12 DD15 GG10 5F046 MA02 MA12 MA17 MA18

Claims (8)

[Claims] 1. A rinsing liquid for use in a rinsing process after etching a substrate using a photoresist pattern provided on the substrate as a mask, ashing, and then treating a residue after the ashing with a stripping solution. A rinsing solution for photolithography, wherein the rinsing solution has a pH of 8 to 12, and contains at least one selected from a chelating agent and a saccharide. 2. The chelating agent is an aromatic hydroxy compound,
The rinsing liquid for photolithography according to claim 1, wherein the rinsing liquid is at least one selected from benzotriazole and derivatives thereof. 3. The method according to claim 1, which comprises hydroxylamines and one or more amines having an acid dissociation constant (pKa) of 7.5 to 13 in an aqueous solution at 25 ° C. Rinse solution for photolithography. 4. Hydroxylamines represented by the following general formula (I): (Wherein, R ^1, R ² each independently represent a hydrogen atom, a lower alkyl group having 1 to 6 carbon atoms) is a compound represented by claim 3 photo rinse solution for lithography described. 5. The photolithography rinsing liquid according to claim 1, further comprising ammonia water. 6. A stripping solution for stripping and removing residues after ashing is at least one selected from hydrofluoric acid or a salt of hydrofluoric acid and a base containing no metal ion. The rinse solution for photolithography according to any one of claims 1 to 5, comprising: 7. A step of selectively exposing and developing a photoresist layer provided on a substrate having a metal layer to form a photoresist pattern, and (II) etching a substrate using the photoresist pattern as a mask to form a metal wiring. Forming a pattern, (III) ashing the photoresist pattern, (IV) treating the substrate after the ashing step with a stripping solution to strip and remove the residue after the ashing,
(V) a step of rinsing the substrate by contacting the substrate with a rinsing liquid after the above-mentioned processing; and (VI) a step of rinsing the substrate with water after the above-mentioned processing, wherein the step (V) Any one of claims 1 to 6
A method for treating a substrate, comprising using the rinsing liquid described in the above section. 8. The stripping solution for stripping and removing the residue after ashing is at least one selected from hydrofluoric acid or a salt of hydrofluoric acid and a base containing no metal ion. The method for treating a substrate according to claim 7, comprising: