JP2001242642A - Post-ashing treatment solution and treatment method using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a post-ashing treatment solution which prevents the corrosion of metallic wiring and reliably removes residue such as a degenerated photoresist film and a metallic deposition from a substrate subjected a ashing after dry etching under severer conditions in an ultrafine patterning process and a treatment method using the solution. SOLUTION: The post-ashing treatment solution contains the salt of hydrofluoric acid and a metal ion-free base and is prepared by blending at least a polyol and a water-soluble organic solvent other than polyols. A substrate is subjected to ashing after etching through a photoresist pattern disposed on the substrate as a mask and then the substrate is treated by applying the solution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a processing solution after ashing and a processing method using the same. More specifically, the present invention relates to a processing solution excellent in processing a substrate which has been subjected to dry etching and subsequently ashing using a photoresist pattern provided on the substrate as a mask, and a processing method using the same. 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 layers deposited on a substrate by CVD or SiO _2.
A photoresist is uniformly coated on an insulating layer such as a layer, and selectively exposed and developed to form a photoresist pattern. Using the pattern as a mask, the metal layer, the SiO ₂ layer, etc. It is manufactured by selectively etching a substrate on which a semiconductor layer such as an insulating layer, a low-temperature polysilicon film, and an amorphous silicon film is formed to form a fine circuit, and then removing an unnecessary photoresist layer.

Here, the metal layer deposited by CVD includes aluminum (Al); aluminum-silicon (A).
aluminum alloys (Al alloys) such as l-Si), aluminum-copper (Al-Cu), aluminum-silicon-copper (Al-Si-Cu); titanium (Ti); titanium nitride (TiN), titanium tungsten ( Titanium alloys (Ti alloys) such as TiW); tantalum (Ta), tantalum nitride (TaN), tungsten (W), tungsten nitride (WN), copper (Cu), cobalt silicide (CoS)
i) and the like are 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,
Residues such as a deteriorated photoresist film remain in a square shape on the side and bottom of the pattern, or residues derived from other components adhere and remain, and also when shaving the metal layer at the time of etching. Metal deposition occurs. Therefore, if these are not completely removed, problems such as a decrease in the yield of semiconductor manufacturing occur.

These residues and metal depositions have different compositions depending on the type of etching gas and ashing conditions, the type of metal formed on the substrate, the type of insulating layer, the type of photoresist used, and the like. Generated. Due to the severe processing conditions in various processes and the diversification of metals, insulating layers, and photoresists used in various processes associated with various improvements in semiconductors in recent years, residues and metal deposition have become complicated, and their composition has been determined. However, there is no satisfactory processing solution and processing method.

[0006] More recently, there has been a tendency to further miniaturize patterns, and ultrafine patterns having a size of 0.2 to 0.3 µm or less have been used. In a substrate on which such an ultra-fine pattern is formed, the conditions of etching and ashing are more severe, and the requirements for corrosion resistance of metal wiring, removal of residue, etc. are much higher than before. It has become.

Conventionally, a composition containing a fluorine-containing compound such as hydrofluoric acid has been frequently used as a composition for removing a deteriorated film of a photoresist or a treatment solution after ashing. A semiconductor device detergent containing a quaternary ammonium salt and a fluorine compound, an organic solvent (Japanese Patent Application Laid-Open No. 7-2017794), a salt of hydrofluoric acid with a base not containing a metal ion, and a water-soluble organic compound. A cleaning agent for a semiconductor device containing a solvent and having a system pH of 5 to 8 (JP-A-9-197681), a fluorine compound, a water-soluble organic solvent, and a specific amount of water. JP-A-11-67632), a specific quaternary ammonium hydroxide, a nucleophilic amine compound having a redox potential, a saccharide and / or a sugar alcohol, and water. The like release agent containing (JP-A-9-283507) in a specific mixing ratio are known.

However, with the conventional processing solutions and cleaning agents described in these publications, under the severe etching and ashing processing conditions in the current ultrafine patterning process, corrosion of the metal wiring is prevented and the photoresist is deteriorated. It has become difficult to reliably remove residues such as films and metal deposition.

By the way, in such a processing solution or cleaning agent containing a fluorine-based compound such as hydrofluoric acid, water is usually mixed to dissolve the fluorine-based compound, thereby improving the removability of the residue after ashing. Have improved. However,
Water formulation, on the other hand, has the problem of causing corrosion of the metal layer. If the amount of water is reduced or water is not added, it is effective in inhibiting corrosion of the metal layer, but a new problem of precipitation of fluorine-based compounds arises.

[0010] In the case of a treatment solution containing a fluorine compound such as hydrofluoric acid, a water rinsing treatment is usually performed after the treatment of the substrate, but there is a problem that corrosion is likely to occur at this time.

Therefore, the treatment liquid containing a fluorine compound such as hydrofluoric acid is excellent in preventing precipitation of the fluorine compound, removing residue after ashing, and preventing corrosion of the metal film. Development of a processing solution has been required.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been made in consideration of the corrosion of metal wiring on a substrate which has been subjected to dry etching under severer conditions in an ultrafine patterning process and subsequently to ashing. And a treatment solution after ashing which can reliably remove residues such as a deteriorated photoresist film and metal deposition, and can effectively prevent corrosion during residue removal processing and water rinsing. It is an object to provide a processing method used. In particular, the present invention, in a treatment solution containing a fluorine compound such as hydrofluoric acid, reduces the amount of water, or even when water is not added, while preventing the precipitation of the fluorine compound, and after ashing It is an object of the present invention to provide a processing solution and a processing method which are excellent in removing residue and metal deposition and preventing corrosion of a metal film.

[0013]

SUMMARY OF THE INVENTION The present inventors have found that, in a conventional treatment solution containing hydrofluoric acid, when the content of water is increased, corrosion of a metal layer or a metal oxide layer occurs, and conversely, When the content is reduced, problems such as the precipitation of fluorine-based compounds occur, and it is difficult to balance the two. As a solvent of a salt of a hydroacid and a base not containing a metal ion, a polyhydric alcohol,
The inventors have found that the above problem can be solved by using a mixed solvent with a water-soluble organic solvent other than a polyhydric alcohol, and have completed the present invention.

That is, the present invention relates to (a) a post-ashing treatment solution containing a salt of hydrofluoric acid and a base containing no metal ion, (b) a polyhydric alcohol, and (c)
The present invention relates to a treatment liquid after ashing, which comprises a water-soluble organic solvent (excluding the component (b)).

In the above, it is preferable that the component (b) is contained in an amount of 10 to 70% by weight, and it is further preferable that the component (c) is added in an amount of 10 to 80% by weight. Further, (d) water may be blended.

The present invention also provides (I) a step of providing a photoresist layer on a substrate having a metal layer, (II) a step of selectively exposing the photoresist layer, and (III) developing the exposed photoresist layer. Providing a photoresist pattern, (I
V) a step of etching the substrate using the photoresist pattern as a mask to form a metal wiring pattern, (V) ashing the photoresist pattern, and (VI)
A step of contacting the substrate after the ashing step with a processing liquid to perform processing, and (VII) a step of rinsing the substrate with water after the above processing, further comprising the step of: And a processing method characterized by processing.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The component (a) used in the treatment liquid of the present invention is a salt of hydrofluoric acid and a base containing no metal ion. Here, the base not containing a metal ion includes organic amines such as hydroxylamines, primary, secondary and tertiary aliphatic amines, alicyclic amines, aromatic amines, and heterocyclic amines. , Ammonia water, lower alkyl quaternary ammonium base and the like are preferably used.

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

Specific examples of the primary aliphatic amine include 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.

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.

The base containing no metal ion may be used alone, or two or more bases may be used in combination.

The salt of a metal ion-free base with hydrofluoric acid can be prepared by adding a metal ion-free base to a commercially available hydrofluoric acid having a concentration of 50 to 60%, Can be produced by adding so as to be about 5 to 8. As such a salt, ammonium fluoride (NH ₄ F) is most preferably used.
As the component (a), one type or two or more types can be used.

The upper limit of the amount of the component (a) in the treatment solution of the present invention is 10 from the viewpoint that the balance between the removability of the residue and the corrosion resistance of the metal wiring during the water rinsing treatment is more effectively balanced. % By weight, and particularly preferably 5% by weight. The lower limit is preferably 0.01% by weight, particularly preferably 0.05% by weight.

Examples of the polyhydric alcohol as the component (b) include ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, and glycerin. Among them,
Propylene glycol is most preferably used in terms of safety and the like. One or more polyhydric alcohols can be used.

The upper limit of the amount of the component (b) in the treating solution of the present invention is 70 from the viewpoint of more effectively balancing the removability of the residue and the corrosion resistance of the metal wiring during the water rinsing treatment. % By weight, and particularly preferably 60% by weight.
The lower limit is preferably 10% by weight, particularly preferably 20% by weight.

The component (c) is a water-soluble organic solvent other than the component (b), and may be any organic solvent that is miscible with water and other components of the present invention.

Examples of such a water-soluble organic solvent include sulfoxides such as dimethyl sulfoxide; dimethyl sulfone, diethyl sulfone, bis (2-hydroxyethyl)
Sulfones such as sulfone and tetramethylene sulfone;
Amides such as N, N-dimethylformamide, N-methylformamide, N, N-dimethylacetamide, N-methylacetamide, N, N-diethylacetamide;
N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N-hydroxymethyl-2-pyrrolidone, N-hydroxyethyl-2-
Lactams such as pyrrolidone; imidazolidinones such as 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone and 1,3-diisopropyl-2-imidazolidinone; γ- Lactones such as butyrolactone and δ-valerolactone. Among these, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-
2-Pyrrolidone and 1,3-dimethyl-2-imidazolidinone are preferred from the viewpoint that the residue can be removed and the corrosion protection margin is wide. Among them, dimethyl sulfoxide, N-methyl-2-pyrrolidone and the like are particularly preferable because of their excellent anticorrosion effect on the substrate. As the component (c), one type or two or more types can be used.

The upper limit of the compounding amount of the component (c) in the treatment liquid of the present invention is 80 from the viewpoint that the balance between the removability of the residue and the corrosion resistance of the metal wiring during the water rinsing treatment is more effectively balanced. % By weight, and particularly preferably 70% by weight.
The lower limit is preferably 10% by weight, particularly preferably 15% by weight.

The water of the component (d) is inevitably contained in the components (b) and (c), but may be further added in the present invention. The component (d) contains the remainder of the amount of the other components, but in the present invention, the upper limit of the amount of the component (d) is preferably 40% by weight, particularly 30% by weight from the viewpoint of improving the removability of the residue. Is preferred. The lower limit is preferably 8% by weight, particularly preferably 10% by weight.

In the present invention, by using the component (b) and the component (c), they become a mixed solvent, thereby enabling the component (a) to be sufficiently dissolved.
Even when the amount of the component (d) is reduced or the component (d) is not added, the precipitation of the component (a), which has been a problem in the conventional hydrofluoric acid compounding system, can be prevented. Thus, it is possible to balance both the corrosion prevention of the metal layer and the removal of the ashing residue.

The treating solution of the present invention is added with components (a) to (c) and, if desired, component (d) to form a 0.1% solution.
Etching and ashing of a substrate on which an ultrafine photoresist pattern of 2 to 0.3 μm or less has been formed can reliably remove residues such as a deteriorated photoresist film and metal deposition. Further, corrosion of various metal wirings, metal layers, and metal insulating layers deposited by CVD can be effectively prevented.

The treatment liquid of the present invention may further contain, as optional additives, a basic compound, hydrofluoric acid, an anticorrosive and the like in addition to the above components (a) to (c) and component (d). it can.

The basic compound is preferably blended within a pH range of about 8.5 to 10. By adjusting the pH of the system within the above range by adding a basic compound, the anticorrosion effect at the time of rinsing with water during substrate processing can be further enhanced. Preferred examples of the basic compound include ammonia water, hydroxylamines, and amines having an acid dissociation constant (pKa) of 7.5 to 13 in an aqueous solution at 25 ° C.

The above hydroxylamines are represented by the following general formula (I)

[0042]

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).

As the lower alkyl group having 1 to 6 carbon atoms,
Methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-
Examples thereof include a butyl group, a pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a hexyl group, an isohexyl group, a 3-methylpentyl group, a 2,2-dimethylbutyl group, and a 2,3-dimethylbutyl group. .

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

Examples of the amines having an acid dissociation constant (pKa) of 7.5 to 13 in the aqueous solution at 25 ° C. include monoethanolamine, diethanolamine, triethanolamine, and 2- (2-aminoethoxy) ethanol. N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-dibutylethanolamine, N-methylethanolamine, N-ethylethanolamine, N-butylethanolamine, N-methyldiethanolamine, monoisopropanol Alkanolamines such as amine, diisopropanolamine and triisopropanolamine; diethylenetriamine, triethylenetetramine, propylenediamine, N, N-
Diethylethylenediamine, N, N'-diethylethylenediamine, 1,4-butanediamine, N-ethyl-ethylenediamine, 1,2-propanediamine, 1,3-
Polyalkylenepolyamines such as propanediamine and 1,6-hexanediamine; aliphatic amines such as 2-ethyl-hexylamine, dioctylamine, tributylamine, tripropylamine, triallylamine, heptylamine and cyclohexylamine; benzylamine ,
Aromatic amines such as diphenylamine; piperazine, N
And cyclic amines such as -methyl-piperazine, methyl-piperazine and hydroxylethylpiperazine. Among them, those having a pKa of 8.5 to 11.5 are preferable from the viewpoint of an anticorrosion effect on metal wiring, and specifically, monoethanolamine, 2- (2-aminoethoxy) ethanol, diethylenetriamine, and triethylenetetramine. , Cyclohexylamine, piperazine and the like are preferred. One or more of these amines can be used.

Hydrofluoric acid is preferably blended for further improving the residue removing property. When hydrofluoric acid is compounded, the amount is preferably about 0.02 to 0.5% by weight, particularly about 0.05 to 0.2% by weight.

As the anticorrosive, those conventionally used can be arbitrarily used. Such compounds include, for example, aromatic hydroxy compounds, benzotriazole compounds, sugar alcohols and the like.

Specific examples of the aromatic hydroxy compound include phenol, cresol, xylenol, pyrocatechol (= 1,2-dihydroxybenzene), te
rt-butylcatechol, resorcinol, hydroquinone, pyrogallol, 1,2,4-benzenetriol,
Salicyl alcohol, p-hydroxybenzyl alcohol, o-hydroxybenzyl alcohol, p-hydroxyphenethyl alcohol, p-aminophenol, m-
Aminophenol, diaminophenol, aminoresorcinol, p-hydroxybenzoic acid, o-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid,
Examples thereof include 3,5-dihydroxybenzoic acid and gallic acid. Among them, pyrocatechol, tert-butylcatechol, pyrogallol, and gallic acid are preferably used. One or more aromatic hydroxy compounds can be used.

The benzotriazole-based compound is represented by the following general formula (II)

[0051]

Embedded image

[Wherein Q is a hydrogen atom, a hydroxyl group, a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms (however, the structure may have an amide bond or an ester bond), An aryl group or

[0053]

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 having 1 to 6 carbon atoms. Or an alkoxyalkyl group); R ³ and R ⁴ each independently represent a hydrogen atom, a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms,
Carboxyl group, amino group, hydroxyl group, cyano group, formyl group, sulfonylalkyl group, or sulfo group]
A benzotriazole-based compound represented by the formula:

"Hydrocarbon group" is an organic group consisting of 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.

In the case of a substrate on which pure Cu wiring is formed, Q in the general formula (II) is particularly preferably a group represented by the above formula (3). Among them, in Chemical formula 3, it is preferable to independently select a hydroxyalkyl group or an alkoxyalkyl group having 1 to 6 carbon atoms as R ⁶ and R ⁷ . When at least one of R ⁶ and R ⁷ is an alkyl group having 1 to 6 carbon atoms, the properties of the benzotriazole-based compound having such a composition become poor in water-solubility. When the components are present in the processing solution, they are preferably used.

In the general formula (II), those which represent a water-soluble group as Q are also preferably used. Specifically, a hydrogen atom, an alkyl group having 1 to 3 carbon atoms (that is, a methyl group, an ethyl group, a propyl group, an isopropyl group), a hydroxyalkyl group having 1 to 3 carbon atoms, a hydroxyl group, and the like,
It is preferable in terms of the anticorrosion property of the inorganic material layer.

Specific examples of the benzotriazole compound include, for example, benzotriazole, 5,6-dimethylbenzotriazole, 1-hydroxybenzotriazole, 1-methylbenzotriazole, 1-aminobenzotriazole, 1-phenylbenzotriazole , 1
-Hydroxymethylbenzotriazole, methyl 1-benzotriazolecarboxylate, 5-benzotriazolecarboxylic acid, 1-methoxy-benzotriazole, 1-
(2,2-dihydroxyethyl) -benzotriazole, 1- (2,3-dihydroxypropyl) benzotriazole, or 2,2 ′-｛[, which is commercially available from Ciba Specialty Chemicals as the “Irgamet” series (4-methyl-1H-benzotriazol-1-yl) methyl] iminodibisethanol,
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, 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] imino} bisethanol and the like are preferably used. One or more benzotriazole-based compounds can be used.

The above saccharides are generally C _n (H ₂ O) _m
And sugar alcohols obtained by reducing the carbonyl group of these sugars, such as D-sorbitol, mannitol, xylitol, erythritol, D-threitol, L-arabinitol,
Ribitol, D-glucitol, galactitol, L-
Rhamnitol, sucrose, starch and the like can be mentioned. Among them, xylitol and D-sorbitol are preferred. One or more saccharides can be used.

As the above anticorrosive, saccharides are preferably used in the system of the treatment solution of the present invention, and xylitol is particularly preferable. When the above anticorrosive is added, the total amount thereof is preferably about 3 to 25% by weight, particularly about 1 to 30% by weight in the treatment liquid of the present invention.

Further, in the present invention, as an optional additive component,
An acetylene alcohol / alkylene oxide adduct may be blended. The acetylene alcohol / alkylene oxide adduct is a substance known per se as a surfactant. In the present invention, by blending the acetylene alcohol / alkylene oxide adduct, the permeability of the treatment liquid itself can be improved, and the wettability can be improved.
Thus, it is considered that the ability to remove metal deposition or the like generated at the bottom of the pattern can be further improved.

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

[0063]

Embedded image

(Where R ⁸ is a hydrogen atom or

[0065]

Embedded image

R ⁹ , R ¹⁰ , R ¹¹ , and R ¹² each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms). Here, as the alkyl group having 1 to 6 carbon atoms, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group , Tert-
Examples include a pentyl group, a hexyl group, an isohexyl group, a 3-methylpentyl group, 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 to be added to the acetylene alcohol, ethylene oxide, propylene oxide or a mixture thereof is preferably used.

In the present invention, the following general formula (IV)

[0070]

Embedded image

(Where R ¹³ is a hydrogen atom or

[0072]

Embedded image

R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms). Here, (n + m) represents an integer of 1 to 30, and the properties 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 “Surfynol” (Air Product and Chloride).
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 treatment liquid of the present invention, acetylene alcohol
When the alkylene oxide is blended, the blending amount is 0.02
It is preferably about 5 to 0.5% by weight, particularly 0.05 to
It is about 0.3% by weight. If the amount is too large, bubbles may be generated, and the improvement of wettability is saturated, and further addition cannot be expected even if added more. On the other hand, if the amount is too small, sufficient effect of wettability to be sought is obtained. Difficult to get.
One or more acetylene alcohol / alkylene oxides can be used.

The treatment solution after ashing of the present invention can be advantageously used for photoresists that can be developed with an aqueous alkali 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 positive photoresist containing a compound which generates an acid upon exposure, a compound which is decomposed by the acid to increase the solubility in an aqueous alkali solution, and an alkali-soluble resin,
(Iii) a compound capable of generating an acid upon exposure, a positive photoresist containing an alkali-soluble resin having a group which is decomposed by the acid and increases the solubility in an aqueous alkali solution, and (iv) a compound capable of generating an acid by light, a crosslinking agent And a negative photoresist containing an alkali-soluble resin, but are not limited thereto.

The processing method of the present invention comprises (I) a step of providing a photoresist layer on a substrate having a metal layer, (II) a step of selectively exposing the photoresist layer, and (III) developing the exposed photoresist layer. (IV) forming a metal wiring pattern by etching a substrate using the photoresist pattern as a mask,
(V) ashing the photoresist pattern, (VI) contacting the substrate after the ashing step with a treatment liquid, and (VII) after the treatment, further rinsing the substrate with water. The method for treating a substrate comprises treating the substrate using the treatment liquid of the present invention described above.

Specifically, for example, a metal / metal oxide layer is formed on a substrate such as a silicon wafer or glass by evaporation or the like, and if desired, an insulating layer such as a SiO ₂ film, a low-temperature polysilicon film, an amorphous silicon film, or the like. And an organic SOG layer for flattening, and then a photoresist layer is formed on these layers.

As the metal / metal oxide layer, aluminum (Al); aluminum-silicon (Al-Si),
Aluminum alloys (A) such as aluminum-copper (Al-Cu) and aluminum-silicon-copper (Al-Si-Cu)
alloy); titanium (Ti); titanium nitride (Ti
N), titanium alloys (Ti alloys) such as titanium tungsten (TiW); tantalum (Ta), tantalum nitride (Ta)
N), tungsten (W), tungsten nitride (W
N), copper (Cu), cobalt silicide (CoSi) or the like is used, and these are formed on the substrate in a single layer or a plurality of layers. In particular, Al; Al-Si, Al-Cu, Al-S
Al alloy such as i-Cu; Ti; Ti such as TiN and TiW
In the case of an alloy, when an ashing process is performed in a later step, a residue adheres and deposition is liable to occur. Therefore, the treatment liquid of the present invention is used for removing the residue and forming the metal / metal oxide layer. This can be particularly effective in preventing corrosion of steel.

A known organic SOG layer can be used. The SOG layer is a silicon oxide film formed by applying a coating solution containing a silicon compound on a substrate, and the organic SOG layer is formed by adding a lower alkali (for example, CH _{3) to} Si of the silicon oxide film.
And the like).

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 metal layer and the insulating layer 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, the resist residue (photoresist deteriorated film) after ashing and the metal deposition generated during the etching of the metal layer adhere and remain as residue on the substrate surface.

These residues are brought into contact with the treatment liquid of the present invention to remove residues and metal deposition on the substrate. By using the treatment liquid of the present invention, these residues such as a deteriorated photoresist film and metal deposition can be easily removed. In particular, it is excellent in the effect of preventing corrosion on a substrate having a metal such as Al or an Al alloy.

The contact of the substrate with the processing liquid after ashing is performed by, for example, a paddle method, a dipping method, a shower method, or the like. Here, the paddle method is a single-wafer processing method, in which a cleaning liquid is dropped from a nozzle for each substrate, the processing liquid is brought into contact with the processing liquid for a certain period of time using surface tension, and then the substrate is rotated with a spinner or the like. This refers to a method in which the treatment is carried out by causing the liquid to flow. The dip method refers to a method of performing processing by immersing a wafer together with a wafer cassette in a bath filled with a processing solution for a certain period of time. The shower method refers to a method in which a wafer is rotated together with a cassette, and processing is performed by spraying a processing liquid from a plurality of nozzles in one direction.

After the residue removal treatment, a water rinsing treatment is performed. Conventionally, in a stripping solution or a cleaning agent containing a fluorine-based compound such as hydrofluoric acid, corrosion was easily generated during this water rinsing treatment. On the other hand, in the present invention, corrosion was also prevented during water rinsing treatment. be able to.

The processing solution and the processing method using the same according to the present invention are capable of etching a substrate on which an ultrafine photoresist pattern of 0.2 to 0.3 μm or less is formed,
It has excellent removability to a deteriorated photoresist film and metal deposition generated after ashing, and can effectively prevent corrosion of various metal wirings and metal layers.

[0088]

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.
Indicated by

(Examples 1 to 5, Comparative Examples 1 to 3)

[Removability of post-ashing residue] SiO ₂
A silicon wafer having a layer formed thereon is used as a substrate, a TiN layer as a first layer, an Al—Cu layer as a second layer, and a TiN layer as a third layer are formed on the substrate, and a naphthoquinonediazide compound and a novolak are formed thereon. THMR-iP3300 (manufactured by Tokyo Ohka Kogyo Co., Ltd.), which is a positive photoresist composition made of a resin, is applied by spinner coating, and the resultant is heated at 90 ° C. for 9 hours.
Pre-baking was performed for 0 second to form a photoresist layer having a thickness of 0.2 μm. This photoresist layer was coated with NSR-20.
Exposure through a mask pattern using a 05i10D (manufactured by Nikon Corporation), development processing using a 2.38 wt% aqueous solution of tetramethylammonium hydroxide (TMAH), and a 0.3 μm line and space photoresist Got the 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.), the substrate was etched at a pressure of 0.7 Pa and a stage temperature of 20 ° C. for 168 seconds using a mixed gas of chlorine and boron trichloride as an etchant. Pressure 2.7 Pa, stage temperature 20 ° C.
For 30 seconds to perform an after-corrosion treatment (a treatment excluding chlorine atoms).

Next, the ashing device TCA-3822
A plasma ashing process of a 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.).

Subsequently, the substrate subjected to the plasma ashing treatment was immersed in a treatment solution shown in Table 1 at 23 ° C. for 10 minutes to remove the residue after the ashing. The degree of removal of the residue at this time was observed with a SEM (scanning electron microscope) photograph and evaluated according to the following criteria. Table 2 shows the results. (Evaluation) A: The residue was completely removed. B: The removal of the residue was incomplete.

[Corrosion resistance to metal wiring] Al wiring was provided on a silicon wafer on which an SiO ₂ layer was formed. This was immersed in a 40% aqueous solution obtained by diluting each of the treatment solutions shown in Table 1 2.5 times with water at 23 ° C. for 20 minutes. This substrate was further washed with pure water. Al at this time
The state of corrosion of the wiring was observed with a SEM (scanning electron microscope) photograph and evaluated according to the following criteria. Table 2 shows the results. (Evaluation) A: No corrosion was observed in Al wiring. B: Corrosion was observed in Al wiring.

[Presence of Precipitate in Treatment Solution] When a treatment solution having the composition shown in Table 1 was prepared, the presence or absence of precipitates in the solution was visually observed and evaluated according to the following criteria. Table 2 shows the results. (Evaluation) A: No precipitate was formed in the treatment liquid B: A precipitate was formed in the treatment liquid

[0096]

[Table 1]

[0097]

[Table 2]

In Table 1, NH ₄ F is ammonium fluoride; PG is propylene glycol; EG is ethylene glycol; DMSO is dimethyl sulfoxide;
NMP indicates N-methyl-2-pyrrolidone; HF indicates hydrofluoric acid, respectively. The acetylene alcohol / alkylene oxide adduct is referred to as “acetylenol EL”.
And "acetylenol EH" in a ratio of 3: 7 (weight ratio).

[0099]

As described above in detail, according to the present invention, it is possible to improve the processability of a substrate subjected to dry etching and ashing under severer conditions and to prevent corrosion of a substrate on which a metal layer is formed. An excellent processing solution after ashing and a processing method using the same are provided. The processing solution and the processing method of the present invention have a high resistance to a deteriorated photoresist film or metal deposition generated after etching and ashing of a substrate having an ultrafine photoresist pattern of 0.2 to 0.3 μm or less. It has a removal ability and is excellent in the effect of preventing corrosion of various metal wirings (metal layers) and metal insulating layers deposited by CVD.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/306 H01L 21/306 D (72) Inventor Seiichi Kobayashi 150 Nakamaruko, Nakahara-ku, Kawasaki City, Kanagawa Prefecture East F-term (reference) in Keio Kogyo Co., Ltd. (reference)

Claims (7)

[Claims] 1. A treatment liquid after ashing comprising (a) a salt of hydrofluoric acid and a base not containing a metal ion,
A treatment liquid after ashing, comprising at least (b) a polyhydric alcohol and (c) a water-soluble organic solvent (excluding the component (b)). 2. The treatment liquid after ashing according to claim 1, wherein the component (b) is blended in an amount of 10 to 70% by weight. 3. The post-ash treatment liquid according to claim 2, wherein the component (c) is incorporated in an amount of 10 to 80% by weight. 4. The method according to claim 1, further comprising (d) water.
4. The treatment liquid after ashing according to any one of 3. 5. The base which does not contain a metal ion for forming the component (a) includes hydroxylamines, primary, secondary or tertiary aliphatic amines, alicyclic amines, aromatic amines, The post-ashing treatment liquid according to any one of claims 1 to 4, wherein the treatment liquid is at least one selected from a heterocyclic amine, aqueous ammonia, and a lower alkyl quaternary ammonium base. 6. The composition according to claim 1, wherein the component (a) is ammonium fluoride (NH).
Is a ₄ F), the treatment liquid after ashing according to any one of claims 1 to 5. (I) a step of providing a photoresist layer on a substrate having a metal layer, (II) a step of selectively exposing the photoresist layer, and (III) developing the photoresist layer after exposure to form a photoresist pattern. Providing step, (IV) etching the substrate using the photoresist pattern as a mask to form a metal wiring pattern, (V) ashing the photoresist pattern, and (VI) contacting the substrate after the ashing step with a processing liquid. Treating, and (VII)
A method for treating a substrate, comprising a step of rinsing the substrate with water after the treatment, wherein the substrate is treated with the treatment liquid according to any one of claims 1 to 6. Method.