JPH08202052A - Peeling liquid composition for resist - Google Patents

Abstract

PURPOSE: To peel in a short time at low temp. in a good state and to prevent well corrosion of a metal thin film on a substrate by preparing a peeling liquid compsn. from hydrofluoric acid, water-soluble org. solvent and corrosion preventing agent. CONSTITUTION: This compsn. contains hydrofluoric acid, water-soluble org. solvent and corrosion preventing agent. The compounding ratio in the peeling liquid compsn. is 0.5-40wt.% hydrofluoric acid component, 40-99.5wt.% water-soluble org. solvent component and 0.5-40wt.% corrosion preventing agent component. If the proportion of the hydrofluoric acid component is <0.5wt.%, the peeling property of a modified film decreases. If the proportion exceeds 40wt.%, it is not preferable because the substrate, especially an Al or Al-Si substrate which is easily corroded is corroded. If the proportion of the water-soluble org. solvent component is <40wt.%, peeling of an org. film is not enough, and if it exceeds 99.5wt.%, the peeling property of a modified film decreases. If the proportion of the corrosion preventing agent component is <0.5wt.%, a substrate which is easily corroded is corroded, and if it exceeds 40wt.%, the stripping resistance decreases.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist stripping composition, more specifically, a stripping solution at low temperature (room temperature), which is preferably used for producing semiconductor elements such as IC and LSI or liquid crystal panel elements. TECHNICAL FIELD The present invention relates to a resist stripping liquid composition having high properties and less corrosive to a conductive metal film.

[0002]

2. Description of the Related Art Semiconductor elements such as ICs and LSIs and liquid crystal panel elements are provided with a uniform photoresist on a conductive metal film such as aluminum, copper or aluminum alloy formed on a substrate or an insulating film such as a SiO ₂ film. After coating and exposing and developing it to form a resist pattern, the conductive metal film or insulating film is selectively etched using this pattern as a mask to form a fine circuit, and then an unnecessary resist layer is formed. It is manufactured by removing with a stripper.

As a stripping solution for removing the above resist, conventionally, an organic sulfonic acid stripping solution containing an alkylbenzene sulfonic acid as an essential component and an organic amine stripping solution containing an organic amine such as ethanolamine as an essential component have been used. . The organic sulfonic acid-based stripping solution has poor workability because it is used in combination with highly toxic organic compounds such as phenol compounds and chlorobenzene, and also causes environmental problems, and corrodes the conductive metal film of the substrate. It has the drawback of being easy. On the other hand, the organic amine-based stripping solution is less toxic than the organic sulfonic acid-based stripping solution, and does not require complicated processing for waste liquid treatment, and dry etching, ashing,
It is widely used today because of its excellent releasability of an altered film formed by a treatment such as ion implantation and its excellent effect of preventing corrosion of a substrate containing Al, Cu or the like.

[0004]

However, in recent years,
The processing conditions such as dry etching, ashing, and ion implantation adopted in the manufacturing process of semiconductor elements and liquid crystal panel elements have become strict, and the resist film after processing has changed from an organic film to a film having an inorganic property. . Therefore, even if it is treated with an organic amine-based stripping solution, the deteriorated film cannot be sufficiently stripped, and the treatment temperature of the organic amine-based stripping solution is relatively high at 60 to 130 ° C. There is a risk that organic compounds will volatilize and catch fire. Therefore, the peeling process is generally carried out in a fire prevention facility, and not only the facility for that purpose requires a large amount of cost, but also the processing time is long and high throughput (the number of wafers processed per unit time) is required. As a stripping solution for semiconductor elements and liquid crystal panel elements to be used, it is no longer satisfactory. On the other hand, in the multi-layer resist method, a stripping solution using hydrofluoric acid for the purpose of stripping the silicon oxide layer formed on the surface of the silicone-based resist by oxygen plasma treatment has been proposed, for example, in Japanese Patent Application Laid-Open No. 3-205465. However, since the stripping solution is composed of a polar organic solvent, an aqueous solution of hydrofluoric acid, and a surfactant, it has a drawback that it is highly corrosive and easily corrodes the metal thin film on the substrate.

Further, a stripping solution which can be stripped at a low temperature (room temperature) is disclosed in JP-A-64-88548 and JP-A-5-252.
Although proposed in JP-A-59066, all of the stripping solutions described in these publications include organic amines and water, so that they have the drawbacks that the strippability is not sufficient and the corrosion on the substrate is large.

[0006] The inventors of the present invention have conducted extensive studies to solve the above-mentioned drawbacks. As a result, when the stripping solution composition is composed of hydrofluoric acid, a water-soluble organic solvent, and a corrosive agent, The inventors have completed the present invention by discovering that the peeling process can be favorably performed in a short time and the corrosion of the metal thin film on the substrate can be favorably prevented. That is,

According to the present invention, the peeling property of a film which has been deteriorated by the treatments such as dry etching, ashing and ion implantation is excellent even at a low temperature (room temperature), the peeling treatment time can be shortened, and the corrosion of the substrate containing Al or Cu can be prevented. An object of the present invention is to provide a resist stripping composition that can be used.

[0008]

The present invention which achieves the above object relates to a resist stripping composition containing hydrofluoric acid, a water-soluble organic solvent, and an anticorrosive agent.

The stripping solution composition of the present invention contains hydrofluoric acid, and the hydrofluoric acid is 50-60 hydrogen fluoride.
It is an aqueous solution of wt%, and a commercially available product can be used.
Further, if necessary, ammonium fluoride may be preferably used in a weight ratio of 1: 1 to 1:50 with respect to hydrofluoric acid. As the mixture of hydrofluoric acid and ammonium fluoride, a commercially available mixed solution of “buffered hydrofluoric acid” (manufactured by Hashimoto Kasei Co., Ltd.) or the like can be used. By containing ammonium fluoride together with hydrofluoric acid in the stripping solution composition in this way, the hydrogen ion concentration in the stripping solution composition is stabilized, the concentration change in the stripping step is small, and good stripping is achieved. The action can be sustained.

The water-soluble organic solvent used in the stripping solution composition of the present invention may be any organic solvent that is miscible with the hydrofluoric acid, and is the water-soluble organic solvent used in conventional organic amine-based stripping solutions. Can be used. As the water-soluble organic solvent,
Sulfoxides such as dimethyl sulfoxide, dimethyl sulfone, diethyl sulfone, bis (2-hydroxyethyl) sulfone, sulfones such as tetramethylene sulfone, N, N-dimethylformamide, N-methylformamide, N, N-dimethylacetamide, N -Amids such as methylacetamide, N, N-diethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N-hydroxymethyl-2-pyrrolidone, N- Hydroxyethyl-
Lactams such as 2-pyrrolidone, 1,3-dimethyl-2
-Imidazolidinone, 1,3-diethyl-2-imidazolidinone, 1,3-diisopropyl-2-imidazolidinone and other imidazolidinones, γ-butyrolactone, δ
-Lactones such as valerolactone, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether , And polyhydric alcohols such as diethylene glycol monobutyl ether and derivatives thereof. Among these, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide,
N-methyl-2-pyrrolidone, 1,3-dimethyl-2-
Imidazolidinone and diethylene glycol monobutyl ether are preferable because of excellent resist releasability.

The anticorrosive agent used in the stripping solution of the present invention includes aromatic hydroxy compounds, acetylene alcohol,
It is necessary to incorporate at least one anticorrosive agent selected from the group consisting of a carboxyl group-containing organic compound and its anhydride, and a triazole compound. Al, Al-Si, which is easily corroded by adding the anticorrosive,
The substrate such as Al-Si-Cu is not corroded, and the peeling property is further improved.

Among the above anticorrosives, aromatic hydroxy compounds include phenol, cresol, xylenol,
Pyrocatechol, 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, 3,5
Examples thereof include dihydroxybenzoic acid, and among them, pyrocatechol is preferable. These compounds alone,
Alternatively, two or more kinds can be combined and blended.

As acetylene alcohol, 2-butyne-1,4-diol, 3,5-dimethyl-1-hexyne-3-ol, 2-methyl-3-butyn-2-ol, 3-methyl-1- Pentin-3-ol, 3,6-
Dimethyl-4-octyne-3,6-diol, 2,4
Examples include 7,9-tetramethyl-5-decyne-4,7-diol, 2,5-dimethyl-3-hexyne-2,5-diol and the like. 2-butyne-1,4
-Diols are preferred. These acetylene alcohols can be blended alone or in combination of two or more.

Further, as the carboxyl group-containing organic compound and its anhydride, formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, maleic acid, fumaric acid, benzoic acid, Phthalic acid,
1,2,3-benzenetricarboxylic acid, glycolic acid,
Examples thereof include lactic acid, malic acid, citric acid, acetic anhydride, phthalic anhydride, maleic anhydride, succinic anhydride and salicylic acid. Preferred carboxyl group-containing organic compounds include formic acid, phthalic acid, benzoic acid, phthalic anhydride, and salicylic acid, and phthalic acid, phthalic anhydride, and salicylic acid are particularly preferable. These compounds can be blended alone or in combination of two or more.

Further, examples of the triazole compound include benzotriazole, o-tolyltriazole, m-tolyltriazole, p-tolyltriazole, carboxybenzotriazole, 1-hydroxybenzotriazole, nitrobenzotriazole, dihydroxypropylbenzotriazole and the like. In particular, benzotriazole is preferable. These compounds alone,
Alternatively, two or more kinds can be combined and blended.

The above anticorrosive agents can be used in an appropriate combination depending on the resist composition to be used, stripping conditions, conditions for forming a resist-altered film by ashing, ion implantation, plasma treatment or the like, or conditions for subsequent rinse treatment.

The compounding ratio of the release composition of the present invention is (a)
The hydrofluoric acid component is 0.5 to 40% by weight, preferably 0.
5 to 20% by weight, 40 to 9 of (b) water-soluble organic solvent component
9.5% by weight, preferably 60 to 90% by weight, and (c) the anticorrosive component is 0.5 to 40% by weight, preferably,
It is 5 to 25% by weight. If the hydrofluoric acid and ammonium fluoride components are less than the above range, the peeling property of the deteriorated film is lowered, and if it exceeds the above range, the substrate, particularly Al that is easily corroded,
It is not preferable because it corrodes a substrate such as Al-Si or Al-Si-Cu. Further, when the water-soluble organic solvent component is less than the above range, the peeling of the organic film is insufficient, and when it exceeds the above range, the peelability of the deteriorated film is deteriorated. Further, if the content of the corrosive agent is less than the above range, the above-mentioned easily corroded substrate will be corroded, and if it exceeds the above range, the releasability is deteriorated.

The resist stripper composition of the present invention can be advantageously used for resists that can be developed using an aqueous alkaline solution, including negative and positive resists. Examples of the resist include (i) a positive resist containing a naphthoquinonediazide compound and a novolak resin, (ii) a compound that generates an acid upon exposure, a compound that decomposes with an acid and has an increased solubility in an alkaline aqueous solution, and an alkali-soluble resin. A positive resist containing (iii) a compound that generates an acid upon exposure, a positive resist containing an alkali-soluble resin having a group that is decomposed by an acid to increase the solubility in an alkaline aqueous solution, and (iv) an acid is generated by light. Examples thereof include, but are not limited to, a negative resist containing a compound generated, a crosslinking agent and an alkali-soluble resin.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0020]

【Example】

Examples 1 to 6 THMR-iP33, which is a positive resist composed of a naphthoquinonediazide compound and a novolak resin, on a silicon wafer on which an Al-Si-Cu film having a thickness of about 1.0 [mu] m was deposited.
00 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied to a spinner, and 90
Prebaked at 90 ℃ for 90 seconds, film thickness 2.0μm
The resist layer of was formed. This resist layer is NSR-2
It was exposed through a mask pattern using 005i10D (manufactured by Nikon Corporation) and developed with a 2.38 wt% tetramethylammonium hydroxide aqueous solution to form a resist pattern. Then, post baking was performed at 120 ° C. for 90 seconds.

Next, a silicon wafer having an Al—Si—Cu film of about 1.0 μm having a resist pattern formed under the above conditions is vapor-deposited on an etching apparatus TSS-600.
0 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) is used as an etchant with a mixed gas of chlorine and boron trichloride as a etchant at a pressure of 5 mm Torr and a stage temperature of 20 ° C. for 168 seconds. After-corrosion treatment for removing chlorine atoms was performed for 30 seconds at 20 mmTorr and a stage temperature of 20 ° C. After the above processing, an ashing device TCA-2400 is further added.
(Manufactured by Tokyo Ohka Kogyo Co., Ltd.) with oxygen gas at a pressure of 0.3.
The ashing treatment was performed for 150 seconds under the conditions of mmTorr and a stage temperature of 60 ° C.

The treated silicon wafer was immersed in a stripping solution having the composition shown in Table 1 at 23 ° C. for 60 seconds for stripping treatment. The treated substrate is rinsed with pure water, and the peeling state of the ashing residue of the silicon wafer (peelability of the altered film) and the corrosion state of the Al-Si-Cu film are evaluated by SEM (scanning electron microscope) photograph observation. did. Table 1 shows the results.

In Table 1, component (a) is hydrofluoric acid or its component and ammonium fluoride component, component (b) is a water-soluble organic solvent, and component (c) is a corrosion inhibitor. The peelability of the altered film and the corrosiveness of the Al-Si-Cu film were evaluated as follows. A: Good peelability, X: No corrosion B: Incomplete peeling, Y: Corrosion

[0024]

[Table 1] Note) HFA: 50% hydrogen fluoride aqueous solution AHF: 50 wt% ammonium fluoride aqueous solution DEMB: Diethylene glycol monobutyl ether DMI: 1,3-Dimethyl-2-imidazolidinone NMP: N-methyl-2-pyrrolidone DMSO: Dimethyl sulfoxide BT: Benzotriazole

Comparative Examples 1 to 4 In Example 1, except that the stripping solution composition shown in Table 2 was used,
In the same manner as in Example 1, the peelability and corrosiveness of the altered film were evaluated. The results are shown in Table 2.

[0026]

[Table 2] Note) DEMB: Diethylene glycol monobutyl ether DMI: 1,3-Dimethyl-2-imidazolidinone DMAc: Dimethylacetamide BT: Bensotriazole MEA: Monoethanolamine HFA: 50% hydrogen fluoride aqueous solution DMSO: Dimethyl sulfoxide

As is clear from Tables 1 and 2, the resist stripping composition of the present invention satisfactorily strips the deteriorated film at low temperature (room temperature) in a short time without corroding the substrate.

[0028]

EFFECTS OF THE INVENTION The resist stripping composition of the present invention is capable of stripping well even at a low temperature (room temperature) in a short time even if the resist film is denatured under severe treatment conditions.
It does not corrode easily corroded substrates such as Al, Al-Si, and Al-Si-Cu.

Claims (6)

[Claims] 1. A resist stripping composition comprising hydrofluoric acid, a water-soluble organic solvent, and an anticorrosive agent. 2. A hydrofluoric acid component of 0.5 to 40% by weight,
The resist stripper composition according to claim 1, wherein the water-soluble organic solvent component is 40 to 99.5% by weight and the anticorrosive component is 0.5 to 40% by weight. 3. A resist stripping composition containing hydrofluoric acid, ammonium fluoride, a water-soluble organic solvent, and an anticorrosive agent. 4. Hydrofluoric acid and ammonium fluoride components are 0.5 to 40% by weight, and water-soluble organic solvent components are 40 to 9
9.5% by weight and 0.5-40% by weight of the anticorrosive component
The stripper liquid composition for resist according to claim 3, wherein 5. The water-soluble organic solvent is dimethyl sulfoxide,
At least one selected from the group consisting of N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and diethylene glycol monobutyl ether.
The stripper liquid composition for resist according to claim 1 or 3, which is a seed. 6. The anticorrosive agent is at least one selected from the group consisting of aromatic hydroxy compounds, acetylene alcohol, carboxyl group-containing organic compounds and their anhydrides, and triazole compounds.
Alternatively, the resist stripping composition according to the item 3.