KR20080054714A - Alkali compositions for stripping of resist - Google Patents

Abstract

An alkali composition for stripping a resist, and a method for stripping a resist by using the composition are provided to minimize the corrosion of metal or under layer and to remove the resist layer cured or modified by metallic by-product easily at a low temperature within a short time. An alkali composition for stripping a resist comprises 1-15 wt% of an alkyl phosphate compound; 0.1-5 wt% of a hetero ring compound; 30-70 wt% of a protic alkylene glycol monoalkyl ether compound; 20-40 wt% of an alkanolamine compound; and 10-30 wt% of a water-soluble polar solvent compound. Preferably the alkyl phosphate compound is represented by the formula 1, wherein R1, R2 and R3 are independently a C1-C7 hydrocarbon group; and the hetero ring compound is a heterocycloalkyl compound or a heterocycloalkene compound.

Description

Alkali Compositions for Stripping of Resist

The present invention relates to a composition for removing a resist and a method for removing a resist using the same, and more particularly, to an alkaline composition for peeling a resist film from a substrate and a method for peeling a resist using the same, in a manufacturing process of a semiconductor device and a liquid crystal display device. It is about.

Recently, the etching conditions of the metal film or the oxide film have been severed due to the tendency of the ultra-fine pattern of the processed pattern to increase the frequency of deterioration or hardened resist. Although specific etching conditions vary depending on the film quality to be etched, they are largely classified into wet etching using an electrochemical reaction with an etchant and dry etching using a radical reaction of a plasmalized etching gas. According to such etching conditions, resists crosslinked by complex chemical reactions occurring on the resist surface are difficult to remove even using a conventional resist stripper composition. In addition, such a crosslinked resist is difficult to remove even by a plasma ashing process. However, if the cross-linked resist is not completely removed, a resist residue remains on the wiring pattern or between the wiring pattern and the pattern, which may cause disconnection and short circuit in the subsequent process, such as semiconductor devices, liquid crystal display devices, and flat panel display devices. It is the cause of the yield decline in the production of.

As a peeling liquid composition conventionally used for removing a resist, a mixture liquid of (1-20) alkylbenzenesulfonic acid having 10 to 20 carbon atoms and a non-halogenated aromatic hydrocarbon having a boiling point of 150 ° C or higher (Japanese Patent Application No. 51-72503), ① dimethyl or di A mixture of ethyl sulfoxide and organic sulfone (Japanese Patent Application Laid-Open No. 57-84456), alkylarylsulfonic acid having 10 to 20 carbon atoms, ② hydrophilic aromatic sulfonic acid having 6 to 9 carbon atoms, and ③ non-halogenated boiling point of 150 ° C or higher Mixed liquids with aromatic hydrocarbons (US Pat. No. 4,265,294) and the like have been proposed.

However, since these are severely corroded to the metal film and have problems in terms of toxicity, workability and environmental pollution, a peeling liquid composition comprising a mixture of a water-soluble organic amine compound and various organic solvents has been proposed. In particular, a peeling liquid composition containing monoethanolamine (MEA) as an essential component among the water-soluble organic amine compounds is widely used.

For example, (1) organic amines such as MEA, 2- (2-aminoethoxy) ethanol, (2) N, N-dimethylacetamide (DMAc), N, N-dimethylformamide (DMF), and N-methylpyrroli Two-component stripping liquid composition consisting of a polar solvent such as ton (NMP), dimethyl sulfoxide (DMSO), diethylene glycol monoalkyl ether acetate, and methoxyacetoxy propane (US Pat. No. 4,617,251); (1) Alkanolamines such as MEA, diethanolamine (DEA) and triethanolamine (TEA), sulfone compounds such as sulfonic acid, and glycol monoalkyl ethers such as diethylene glycol monobutyl ether at a specific ratio. Composition (Japanese Patent Laid-Open No. 62-49355); (1) Japanese Unexamined Patent Application Publication No. 63-208043 containing water-soluble amines such as MEA and DEA, and 1,3-dimethyl-2-imidazolidinone; Amine compounds such as (1) MEA, ethylenediamine, piperidine, (2) polar solvents such as DMAc, NMP, DMSO, and (3) surfactants (Japanese Patent Laid-Open No. 63-231343); At least one solvent selected from (1) a nitrogen-containing organic hydroxy compound such as MEA, (2) diethylene glycol monoalkyl ether, diethylene glycol dialkyl ether, γ-butyrolactone and 1,3-dimethyl-2-imidazolinone; And (3) A peeling liquid composition in which DMSO is mixed at a specific ratio has been proposed.

However, the stripping solution does not have sufficient peeling ability against the resist, and insufficiently dissolving ability against the polymer material constituting the resist, so that the residue of the resist is reattached to a semiconductor substrate, a glass substrate, or the like due to heat applied during the peeling process. There is a problem in that the evaporation loss amount is short, the short life cycle of the stripper composition. In order to solve this problem, a peeling liquid composition (Japanese Patent Laid-Open No. 4-305653) containing triethanolamine (TEA) as an essential component instead of MEA has been proposed, but it has not solved the problem of insufficient peeling ability.

Moreover, when using the stripping liquid containing the organic acid, water, and surfactant which were disclosed by Unexamined-Japanese-Patent No. 2000-267302, Unexamined-Japanese-Patent No. 10-256210, and the stripping liquid containing organic acid and an aqueous detergent, , The peeling force on the precipitate is weak, and increasing the amount of organic acid in order to increase the removability of the precipitate, there is a problem that the corrosion of the aluminum wiring increases. Therefore, it is a reality that a release agent capable of satisfying both the sediment removal ability and the low corrosion resistance of the aluminum wiring, which is required in a device having a narrow wiring width, has not been obtained yet.

The present invention solves the above problems of the prior art, and is a resist hardened or deteriorated by the harsh conditions resulting from the dry etching, the wet etching and / or ashing process and the metallic by-products etched from the lower metal film during the process. The film can also be easily peeled off at a low temperature in a short time, minimizes corrosion of the lower metal wiring during the peeling process, and can be used simultaneously in the metal process, the insulating film process, and the oxide film process. It is an object to provide a peeling method used.

In order to achieve the above technical problem, the present invention,

The present invention provides an alkali composition for removing a resist, including an alkyl phosphate compound, a heterocyclic compound, a protic alkylene glycol monoalkyl ether compound, an alkanol amine compound, and a water-soluble polar solvent compound, and a peeling method using the same.

As the alkyl phosphate compound, a compound represented by the following Formula 1 may be preferably used.

Wherein R 1, R 2 and R 3 are each independently a hydrocarbon having 1 to 7 carbon atoms.

The stripper according to the present invention can simultaneously remove the resist used in the metal, the insulating film, and the oxide film process, and does not cause corrosion of the metal film.

The alkyl phosphate compound included in the alkaline composition of the present invention has a high removal rate with respect to all the resists used in the manufacture of semiconductors, liquid crystal substrates, organic EL panels, and plasma display panels, and has a high removal rate at the interface between the substrate and the resist. Due to its good permeability, it is effective in removing denaturation, cured resist and dry etch residue. In addition, it has a high boiling point and flash point, low toxicity, and excellent compatibility with water and organic compounds, making it suitable as a resist removing composition.

Specific examples of the alkyl phosphate compound represented by Chemical Formula 1 in the present invention include trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, and tripentyl phosphate, and these may be used alone or in combination of two or more thereof. have.

In the alkaline composition of the present invention, the alkyl phosphate compound is preferably included in an amount of 1 to 15% by weight, and when included in an amount less than 1% by weight, the alkylphosphate compound does not have sufficient effects on the removal of denaturation, cured resist, and dry etching residues. Inclusion in excess results in a relatively low content of other constituents, resulting in insufficient denaturation, hardened resist and dry etch residue removal.

The heterocyclic compound included in the alkaline composition of the present invention serves to improve the removal performance of the dry etching residue.

In the present invention, the heterocyclic compound includes a heterocycloalkyl compound or a heterocycloalkene compound.

The heterocycloalkyl compound used in the present invention means a cyclic compound having 3-8 carbon atoms, wherein up to 3 carbon atoms can be replaced with one or more hetero atoms selected from O, S and N. Specific examples of the heterocycloalkyl compound include pyrrolidine, piperidine, piperazine, morpholine, and the like, and these may be used alone or in combination of two or more thereof.

The heterocycloalkene compound used in the present invention may contain one phase double bond in 3-8 unsaturated ring compounds in which carbon is substituted with one or more heteroatoms selected from O, S and N. . Specific examples of the heterocycloalkene compound include pyridine, limidine, pyridazine, pyrazine, pyran, pyrazole, thiophene, imidazole, triazole, tetrazole, oxazole, thiazole, and the like. Or two or more kinds may be used together.

In the alkaline composition of the present invention, the heterocyclic compound is preferably contained in 0.1 to 5% by weight. When the heterocyclic compound is contained in less than 0.1% by weight, the removal effect of the dry etching residues is insignificant, and when contained in more than 5% by weight, the removal effect of the dry etching residues does not increase any more and converges within a certain range. do.

In the alkaline composition of the present invention, the protic alkylene glycol monoalkyl ether compound serves to increase the solubility of the dry etching residue. Preferred examples of the quantum alkylene glycol monoalkyl ether are ethylene glycol monobutyl ether (BG), diethylene glycol monomethyl ether (MDG), diethylene glycol monoethyl ether (carbitol), diethylene glycol monobutyl ether (BDG ), Dipropylene glycol monomethyl ether (DPM), dipropylene glycol monoethyl ether (MFDG), triethylene glycol monobutyl ether (BTG), triethylene glycol monoethyl ether (MTG), propylene glycol monomethyl ether (MFG) Etc. can be mentioned. These may be used alone or in combination of two or more.

In the alkaline composition of the present invention, the protic alkylene glycol monoalkyl ether compound is preferably contained in 30 to 70% by weight. If the content is less than 30% by weight, the increase in the dissolving power of the dry etching residue of the release agent composition due to the addition of the protic alkylene glycol monoalkyl ether cannot be expected, and when included in excess of 70% by weight, the content of other compounds exhibiting a peeling effect. This becomes relatively low, and causes a fall of peeling effect.

Preferred examples of the alkanol amine compound which is an alkaline compound used in the alkaline composition of the present invention include monoethanolamine, diethanolamine, 2-aminoethanol, 2- (ethylamino) ethanol, 2- (methylamino) ethanol, N -Methyl diethanolamine, dimethylaminoethanol, diethylaminoethanol, 2- (2-aminoethoxy) ethanol, 1-amino- 2-propanol, triethanolamine, monopropanol amine, dibutanol amine and the like. These may be used alone or in combination of two or more.

In the alkaline composition of the present invention, the alkanol amine compound is preferably contained in 20 to 40% by weight. If it is included in less than 20% by weight, it is not possible to achieve a sufficient cleaning effect, when contained in excess of 40% by weight, the corrosion protection for aluminum or aluminum alloy wiring is reduced.

In the alkaline composition of the present invention, a water-soluble polar solvent compound is a solvent having excellent solubility in a polymer resin, and examples thereof include N-methylpyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinone (DMI), Dimethyl sulfoxide (DMSO), dimethyl acetamide (DMAc), dimethylformamide (DMF), tetrahydrofurfuryl alcohol, isophorone, diethyl adipate, dimethyl glutarate, sulfolane, gamma-butyllactone (GBL) And N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO) and the like are particularly preferred. These may be used alone or in combination of two or more.

In the alkaline composition of the present invention, the water-soluble polar solvent compound is preferably contained in 10 to 30% by weight. When used at less than 10% by weight, the dissolving ability of the cured or polymer-modified resist is lowered, and when used at more than 30% by weight, the effect of removing the resist and improving the cleaning power cannot be expected.

It is preferable that the alkali composition of this invention does not contain water and an organic acid, in order to avoid weakening of peeling force and corrosion of metal wiring. In order to raise the resist removal rate, it heats at the temperature of 50-100 degreeC. At this time, in the case of the composition containing water causes corrosion of the aluminum wiring, there is a change in the composition by evaporation, there is a problem in long-term use. In addition, the addition of an organic acid for preventing corrosion or adjusting pH is not included in the composition of the present invention because the peeling force is weakened by weakening alkalinity.

It is preferable that pH of the alkali composition of this invention is 10-13. If the pH is less than 10, there is a problem that the peel force is weak, if more than 13 there is a problem that the corrosion to the metal proceeds rapidly.

The alkaline composition of the present invention may further include a pH adjuster if necessary, and examples of the pH adjuster include ammonium salts such as ammonium phosphate and ammonium sulfate.

The alkali composition for resist stripping of the present invention can be used simultaneously in a metal step, an insulating film step, and an oxide film step.

As the peeling method using the alkaline composition of the present invention, a method of spraying the peeling solution on the surface of the resist-coated substrate or dipping the substrate into a bath containing the peeling liquid can be used. That is, a spray method, a spin method, a dipping method, or a dipping method using ultrasonic waves may be used.

Such a wet process can effectively remove the resist on the substrate, and when the removal efficiency is expected, it is advantageous to lengthen the wet process time, but considering the productivity, the wet process time is preferably about 30 seconds to 20 minutes. .

In the following, preferred embodiments are presented to help understand the present invention. However, the following examples are merely provided to more easily understand the present invention, and the contents of the present invention are not limited thereto.

Example  One: Resist  Preparation of Alkali Composition for Peeling

As a peeling solution, 10 weight% of tributyl phosphates, 1 weight% of piperazine, 35 weight% of diethylene glycol monobutyl ether, 24 weight% of dimethyl sulfoxide, and 30 weight% of monoethanolamine were prepared by mixing and stirring.

Example  2-8 and Comparative example  1-4: Resist  Preparation of Alkali Composition for Peeling

To the peeling solution was prepared in the same manner as in Example 1 according to the composition of Table 1.

Alkyl phosphate compound Heterocyclic compounds Alkylene glycol monoalkyl ether compound Alkanolamine Compound Water Soluble Polar Solvent Compound pH Kinds Ingredient (% by weight) Kinds Ingredient (% by weight) Kinds Ingredient (% by weight) Kinds Ingredient (% by weight) Kinds Ingredient (% by weight) Example 1 TBP 10 Piperazine One BDG 35 MEA 30 DMSO 24 11.6 Example 2 TEP 10 Pyrrolidine One MDG 35 MEA 30 DMSO 24 11.7 Example 3 TBP 10 Piperazine 2 BDG 33 MEA 30 DMSO 25 11.5 Example 4 TEP 10 Piperidine 2 BDG 33 MEA 30 DMSO 25 11.6 Example 5 TBP 10 Piperazine One MDG 40 MPA 25 DMSO 24 11.4 Example 6 TEP 10 Morpholine One MDG 40 MPA 25 DMSO 24 11.4 Example 7 TBP 10 Piperazine 2 MDG 38 MPA 30 NMP 20 11.6 Example 8 TEP 10 Piperazine 2 BDG 38 MPA 30 NMP 20 11.6 Comparative Example 1 GA (organic acid) 10 DI 15 BDG 40 MEA 20 NMP 15 9.2 Comparative Example 2 TMAH (alkali) 10 DI 20 BDG 40 MEA 20 NMP 10 13.5 Comparative Example 3 - - DI 20 BDG 40 MEA 25 NMP 15 10.9 Comparative Example 4 TBP 0.5 Piperazine 9.5 BDG 35 MEA 30 DMSO 25 11.1 Comparative Example 5 TBP 20 Piperazine - BDG 25 MEA 30 DMSO 25 11.3

TBP: tributyl phosphate

TEP: triethylphosphate

DI: water

BDG: diethylene glycol monobutyl ether

MDG: diethylene glycol monomethyl ether

MEA: monoethanolamine

MPA: 1-amino-2-propanol

DMSO: Dimethylsulfoxide

NMP: N-methylpyrrolidone

GA: Gallic acid

Test Example  One: Peel force  Test

First, a substrate on which a metal (Al), an oxide film (SiO ₂ ), and an insulating film (SiN) were each resist patterned was dipped into a stripping solution prepared in Examples 1 to 8 and Comparative Examples 1 to 10 for 10 minutes. At this time, the temperature of the stripper was 70 ° C. and the shape of the resist was removed was observed by FE-SEM. The test results are shown in Table 2 below.

<Evaluation Criteria>

◎: Excellent peeling force

○: good peeling force

△: peel force normal

ｘ: No peeling force

PR removal power of metal specimen PR removal ability of oxide specimen PR removal force of insulating film specimen Example 1 ◎ ○ ○ Example 2 ◎ ○ ○ Example 3 ◎ ◎ ◎ Example 4 ◎ ◎ ◎ Example 5 ○ ○ ○ Example 6 ○ ○ ○ Example 7 ◎ ◎ ◎ Example 8 ◎ ◎ ○ Comparative Example 1 △ ｘ ｘ Comparative Example 2 ○ ○ △ Comparative Example 3 △ ｘ ｘ Comparative Example 4 △ △ ｘ Comparative Example 5 ○ △ △

As can be seen from the results of Table 2, in the case of the stripping solutions of Examples 1 to 8, all were found to have excellent or good peeling force of the resist, and as in the case of Comparative Examples 1 to 2, the organic acid, alkali or When water is added, the peeling force is weakened because it is outside the pH range of the present invention, and the peeling force is weakened even when the alkylphosphate compound is excluded as in Comparative Example 3. In addition, as in the case of Comparative Examples 4 to 5 it was confirmed that even if the composition content is out of the range of the present invention, the peel force is reduced.

Test Example  2: On metal film  For corrosive testing

In Test Example 1, the degree of surface corrosion of the substrates used in the peel force tests of Examples 3, 4, 7, 8, Comparative Examples 1, and 2 was evaluated. Specimens used for the evaluation were metal (Al), insulating film (SiN), oxide film (SiO2). After the peeling evaluation of Test Example 1 was completed, the surface roughness was measured by AFM, and the results are shown in Table 3.

Metal Substrate RMS (nm) Oxide Substrate RMS (nm) Insulation Substrate RMS (nm) Example 3 12 1.0 6.2 Example 4 13 1.2 7.1 Example 7 12 0.9 6.5 Example 8 11 1.2 7.6 Comparative Example 1 25 3.6 16.7 Comparative Example 2 38 3.8 12.9

As shown in Table 3, when peeling was performed using the stripper composition of the present invention, it was confirmed that there was no corrosion on the metal and the surface roughness due to the residue on the substrate was good.

The alkali composition for resist stripping of the present invention is a resist film cured or altered by harsh conditions resulting from dry etching, wet etching and / or ashing processes and metallic by-products etched from the lower metal film during the above process at a low temperature for a short time. It can be easily peeled off, can minimize the corrosion of the metal and the lower film formed under the peeling process, and can be used simultaneously in the metal process, the insulating film process, and the oxide film process.

Therefore, the semiconductor device and the lithography process can be simplified, and there is an effect of improving the content change due to moisture evaporation at high temperature.

Claims (15)

An alkali composition for resist stripping comprising an alkyl phosphate compound, a heterocyclic compound, a protic alkylene glycol monoalkyl ether compound, an alkanol amine compound, and a water-soluble polar solvent compound. The alkali composition for removing a resist according to claim 1, wherein the alkyl phosphate compound is represented by the following Chemical Formula 1:

(One) Wherein R 1, R 2 and R 3 are each independently a hydrocarbon having 1 to 7 carbon atoms. The alkali composition for resist stripping according to claim 1, wherein the heterocyclic compound is a heterocycloalkyl compound or a heterocycloalkene compound. The alkali composition for resist stripping according to claim 1, wherein the alkyl phosphate compound is at least one selected from the group consisting of trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, and tripentyl phosphate. The method according to claim 1, wherein the heterocyclic compound is pyrrolidine, piperidine, piperazine, morpholine, pyridine, limidine, pyridazine, pyrazine, pyran, pyrazole, thiophene, imidazole, triazole, tetrazole, An alkali composition for resist stripping, characterized in that at least one member selected from the group consisting of oxazole and thiazole. The method of claim 1, wherein the proton alkylene glycol monoalkyl ether compound is ethylene glycol monobutyl ether (BG), diethylene glycol monomethyl ether (MDG), diethylene glycol monoethyl ether (carbitol), diethylene glycol monobutyl ether (BDG), dipropylene glycol monomethyl ether (DPM), dipropylene glycol monoethyl ether (MFDG), triethylene glycol monobutyl ether (BTG), triethylene glycol monoethyl ether (MTG), and propylene glycol monomethyl ether At least one selected from the group consisting of (MFG) is an alkaline composition for resist stripping. The method of claim 1, wherein the alkanol amine compound is monoethanolamine, diethanolamine, 2-aminoethanol, 2- (ethylamino) ethanol, 2- (methylamino) ethanol, N-methyldiethanolamine, dimethylaminoethanol, At least one member selected from the group consisting of diethylaminoethanol, 2- (2-aminoethoxy) ethanol, 1-amino-2-propanol, triethanolamine, monopropanol amine, and dibutanol amine Alkaline composition for use. The method of claim 1, wherein the water-soluble polar solvent compound is N-methylpyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinone (DMI), dimethyl sulfoxide (DMSO), dimethylacetamide (DMAc), At least one member selected from the group consisting of dimethylformamide (DMF), tetrahydrofurfuryl alcohol, isophorone, diethyl adipate, dimethyl glutarate, sulfolane, and gamma-butyllactone (GBL). Alkali composition for resist stripping. The method according to claim 1, 1 to 15% by weight of an alkyl phosphate compound, 0.1 to 5% by weight of a heterocyclic compound, 30 to 70% by weight of a protic alkylene glycol monoalkyl ether compound, 20 to 40% by weight of an alkanol amine compound, and polarity The alkali composition for resist peeling containing 10-30 weight% of solvent compounds. The alkali composition for removing a resist according to claim 1, which does not contain water and an organic acid. The pH is 10-13, The alkali composition for resist peeling of Claim 1 characterized by the above-mentioned. The alkaline composition for removing a resist according to claim 1, further comprising a pH adjusting agent. The alkaline composition for resist stripping according to claim 12, wherein the pH adjusting agent is an ammonium salt. The alkali composition for resist stripping according to any one of claims 1 to 13, which is used in a metal process, an insulation film process, and an oxide film process. The method of peeling a resist in a metal process, an insulation film process, or an oxide film process using the alkali composition for resist peeling in any one of Claims 1-13.