JP2000199971A - Removing solution composition for photoresist and method for removing photoresist using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a removing solution composition for a photoresist having superior removing capability to any of a photoresist film and a degenerated film and capable of effectively preventing the corrosion of a substrate with a formed metallic film, in particular an Al, Al alloy or Ti film, even under conditions of high temperature treatment and to remove a photoresist using the composition. SOLUTION: This removing solution composition consists of (a) 2-30 wt.% hydroxylamines, (b) 2-35 wt.% water, (c) 25-40 wt.% monoethanolamine and/or 2-(2-aminoethoxy) ethanol, (d) 20-32 wt.% N-methyl-2-pyrrolidone and/or diethylene glycol monobutyl ether and (e) 2-20 wt.% aromatic hydroxy compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a photoresist stripping composition and a photoresist stripping method using the same. More specifically, for a photoresist which is preferably used in the manufacture of semiconductor elements such as ICs and LSIs or liquid crystal panel elements and which has excellent peelability of both a photoresist film and a deteriorated film and has excellent corrosion prevention of a substrate even under high temperature processing conditions. The present invention relates to a stripping solution composition and a photoresist stripping method using the same.

[0002]

2. Description of the Related Art For semiconductor elements such as ICs and LSIs and liquid crystal panel elements, a photoresist is uniformly coated on a conductive metal film such as a Nesa film or an insulating film such as a SiO ₂ film formed on a substrate by vapor deposition or the like. Then, this is exposed and developed to form a resist pattern. Using the pattern as a mask, the conductive metal film or the insulating film is selectively etched to form a fine circuit, and then the unnecessary photoresist layer is peeled off. Manufactured by removing with a liquid. Here, as another example of the above metal film,
Aluminum (Al); Aluminum-silicon (Al-
Si), aluminum-silicon-copper (Al-Si-C)
u) and other aluminum alloys (Al alloys); pure titanium (T
i); a titanium alloy (Ti alloy) such as titanium nitride (TiN) or titanium tungsten (TiW); copper (C)
u) and the like. In addition, an inorganic film such as a polysilicon film and an amorphous silicon film may be used. These metal films and inorganic films are formed on the substrate in a single layer or a plurality of layers.

In recent years, a photoresist stripping composition using alkanolamines has been used as a stripping composition for removing the photoresist layer (Japanese Patent Laid-Open No. Sho 62-62).
49355, JP-A-63-208043,
etc).

However, in today's semiconductor device and liquid crystal device manufacturing processes, in addition to the above-described method, it is also necessary to peel off a photoresist film whose photoresist layer has been subjected to dry etching, ashing, ion implantation, and the like. I have. By these processes, the photoresist film after the process becomes a deteriorated film. In recent years, these processing conditions have become more severe, and the deteriorated film has been changed from an organic film to a film having inorganic properties. Therefore, a stripping solution composition using alkanolamines has an adverse effect on the releasability of the deteriorated film. It is enough.

[0005] However, recently, a photoresist stripper composition which is more excellent in stripping the deteriorated film has been developed.
Stripper compositions for photoresists containing hydroxylamines have been proposed. For example, JP-A-4-289866 describes a photoresist stripper composition containing hydroxylamine and alkanolamine.
JP-A-6-266119 discloses a photoresist stripper composition containing hydroxylamine and alkanolamine and further containing a chelating agent (corrosion inhibitor) such as catechol.

[0006] The stripping solution composition containing these hydroxylamines improves the releasability of the deteriorated film as compared with the stripping solution using the above-mentioned alkanolamines.
There is a problem that corrosion appears on a substrate on which an Al alloy such as l-Si or Al-Si-Cu is deposited or on a substrate on which pure titanium (Ti) is deposited. In fact, Japanese Patent Laid-Open No. 6-2
The stripping solution described in JP-A-66199 can prevent corrosion of a titanium alloy, but cannot prevent corrosion of pure titanium (Ti), and has a problem that corrosion occurs.

[0007] To solve the above problems, see, for example, JP-A-9-96.
Japanese Patent Publication No. 911 discloses a photoresist stripping composition containing a specific amount of hydroxylamines, water, amines having a predetermined acid dissociation constant, a water-soluble organic solvent, and an anticorrosive. Excellent, Al and Al alloy,
An excellent anticorrosion effect is also provided for a substrate on which pure titanium (Ti) is formed. However, the stripping solution composition for photoresists described in this publication is not sufficient in strippability of the photoresist film.

In recent years, from the viewpoint of working efficiency and the like, a peeling operation at a higher temperature has been required more than ever before. Generally, the higher the temperature, the better the releasability. However, on the other hand, the metal film on the substrate tends to be corroded more easily. Further, there has been an increasing demand for a stripping solution composition that can cope with stripping of both a photoresist film and a deteriorated film under high-temperature processing conditions.

Therefore, it has excellent peeling properties for both the photoresist film and the deteriorated film, and can be used under a higher temperature treatment condition for a metal film, especially for a substrate on which Al, Al alloy, or Ti is formed. It has been desired to develop a photoresist stripper that can effectively prevent corrosion.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to form a metal film, particularly Al or an Al alloy, even under a higher temperature treatment condition. Substrate or pure titanium (T
A photoresist stripping solution composition which can effectively prevent corrosion on both of the substrates on which i) is formed and has excellent stripping properties on both the photoresist film and the deteriorated film, and using the same. An object of the present invention is to provide a photoresist stripping method.

[0011]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, have found that hydroxylamines, water, specific amines, specific solvents, and aromatic hydroxy compounds have been used. It has been found that the above-mentioned problems can be solved by using a photoresist stripper composition mixed at a specific ratio, and the present invention has been completed based on this.

That is, the present invention provides (a) 2 to 30% by weight of hydroxylamines, (b) 2 to 35% by weight of water,
(C) monoethanolamine and / or 2- (2-
Aminoethoxy) ethanol 25-40% by weight, (d)
The present invention relates to a photoresist stripping composition comprising 20 to 32% by weight of N-methyl-2-pyrrolidone and / or diethylene glycol monobutyl ether and (e) 2 to 20% by weight of an aromatic hydroxy compound.

Further, the present invention relates to at least pure titanium (T
i) The present invention relates to the use of the photoresist stripper composition for stripping a photoresist provided on a substrate on which a metal layer having a layer is formed.

The present invention further provides a step of providing a photoresist layer on a substrate on which a metal layer is formed, a step of selectively exposing the photoresist layer, a step of developing the exposed photoresist layer to provide a resist pattern, Etching the substrate using the pattern as a mask,
Further, if desired, in a photoresist stripping method comprising the steps of: ashing the resist pattern after the etching step; and stripping the resist pattern after the etching step or the ashing step from the substrate, The present invention relates to a photoresist stripping method characterized by stripping a resist pattern after an etching step or an ashing step by using a temperature in the range of 75 to 85 ° C.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The photoresist stripping composition of the present invention will be described below in detail.

In the present invention, "Ti" means "pure titanium" and does not include titanium alloys such as titanium nitride (TiN) and titanium tungsten (TiW).

The hydroxylamines as the component (a) are represented by the following general formula (I)

[0018]

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 preferably used. These hydroxylamines may be used alone or in combination of two or more.

The water as the component (b) is inevitably contained in the component (a), but the amount thereof may be further adjusted.

As the component (c), at least one of monoethanolamine and 2- (2-aminoethoxy) ethanol is used.

As the component (d), at least one of N-methyl-2-pyrrolidone and diethylene glycol monobutyl ether is used.

The aromatic hydroxy compound as the component (e) is mainly for obtaining an anticorrosive effect, and specifically includes phenol, cresol, xylenol, catechol (= 1,2-dihydroxybenzene), tert-butyl. Catechol, 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,
Examples thereof include 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, and 3,5-dihydroxybenzoic acid. Among them, catechol and tert-butyl catechol are preferably used, and tert-butyl catechol is more preferably used from the viewpoint of work safety and the like. These compounds may be used alone or in combination of two or more.

The mixing ratio of the above components (a) to (e) is
Component (a) is 2 to 30% by weight, preferably 5 to 20% by weight, and component (b) is 2 to 35% by weight, preferably 5 to 25%.
% By weight, component (c) is 25 to 40% by weight, preferably 3% by weight.
0 to 35% by weight, component (d) is 20 to 32% by weight, preferably 25 to 30% by weight, and component (e) is 2 to 20% by weight, preferably 3 to 10% by weight. In the present invention, the mixing ratio of the components (a) to (e) is important,
By setting the amount of each component within the above range, both the photoresist film and the deteriorated film can be effectively peeled off, and even if the peeling treatment is performed at a high temperature of about 75 to 85 ° C., the metal Does not corrode the film. Among the components, when the amount of the component (c) exceeds 40% by weight, the peelability of both the photoresist film and the deteriorated film is improved.
Corrosion occurs on the substrate on which the l or Al alloy is formed, while when the component (c) is less than 25% by weight, corrosion occurs on the substrate on which Ti is formed.

Further, in the photoresist stripping composition of the present invention, benzotriazole or a derivative thereof may be blended if necessary. Such a compound includes the following general formula (II)

[0028]

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Wherein R ³ 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) Or an aryl group; R ⁴ and R ⁵ each independently represent a hydrogen atom, a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms, a carboxyl group, an amino group,
Represents a hydroxyl group, a cyano group, a formyl group, a sulfonylalkyl group, or a sulfo group].

In the above, the substituted hydrocarbon group includes
Examples thereof include a hydroxyalkyl group and an alkoxylalkyl group.

In the general formula (II), R ³ is specifically a hydrogen atom, an alkyl group having 1 to 3 carbon atoms (that is, a methyl group, an ethyl group, a propyl group or an isopropyl group), a carbon atom. Preferred are hydroxyalkyl groups, hydroxyl groups, and the like of formulas 1 to 3. Among them, a hydroxyalkyl group having 1 to 3 carbon atoms is particularly preferred.

Specific examples of benzotriazole or derivatives thereof include, for example, benzotriazole, 5,6
-Dimethylbenzotriazole, 1-hydroxybenzotriazole, 1-methylbenzotriazole, 1-aminobenzotriazole, 1-phenylbenzotriazole, 1-hydroxymethylbenzotriazole, 1-
Methyl benzotriazolecarboxylate, 5-benzotriazolecarboxylic acid, 1-methoxybenzotriazole, 1- (2,2-dihydroxyethyl) benzotriazole, 1- (1,2-dihydroxypropyl) benzotriazole, 1- (2 , 3-dihydroxypropyl) benzotriazole and the like. Among these, benzotriazole, 1-hydroxybenzotriazole, 1-methoxybenzotriazole, 1-
(2,2-dihydroxyethyl) benzotriazole,
1- (1,2-dihydroxypropyl) benzotriazole, 1- (2,3-dihydroxypropyl) benzotriazole and the like are preferably used.
-Dihydroxypropyl) benzotriazole is particularly preferably used. These may be used alone or in combination of two or more.

Benzotriazole or a derivative thereof is
When a substrate on which an inorganic film such as copper (Cu) or a polysilicon film is formed is used, it is possible to particularly effectively prevent corrosion of these substrates.

The photoresist stripper composition of the present invention comprises:
It 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 that generates an acid upon exposure, a positive photoresist containing an alkali-soluble resin having a group that is decomposed by an acid and increases the solubility in an alkaline aqueous solution, and (iv) light Examples include, but are not limited to, a negative photoresist containing an acid-generating compound, a crosslinking agent and an alkali-soluble resin.

The photoresist stripping method of the present invention forms a resist pattern obtained by lithography,
Next, there are a case where the photoresist film after the etching step is stripped and a case where the deteriorated film after the ashing step is stripped.

As an example of removing the photoresist film after the former etching step, (I) a step of applying a photoresist composition on a substrate on which a metal layer is formed, drying and providing a photoresist layer, and (II) a step of providing the photoresist layer Is selectively exposed through a mask pattern, (III) a step of developing a photoresist layer after exposure to provide a resist pattern, (IV) a step of etching the substrate using the resist pattern as a mask, and (V) In a photoresist stripping method comprising a step of stripping the resist pattern from the substrate after the etching step, using the photoresist stripper composition of the present invention in a temperature range of 75 to 85 ° C,
There is a method of removing the resist pattern after the etching step.

As an example of peeling off the deteriorated film after the latter ashing step, (I) a step of applying a photoresist composition on a substrate having a metal layer formed thereon and drying to provide a resist layer; Selectively exposing the photoresist layer via a mask pattern, (III) developing the exposed photoresist layer to provide a resist pattern, (IV) etching the substrate using the resist pattern as a mask, V) a photoresist pattern ashing step, and (VI) a photoresist stripping method comprising a step of stripping the resist pattern from the substrate after the ashing step, wherein the photoresist stripping solution composition of the present invention is treated at a temperature of 75 to 85 ° C. And a method of stripping the resist pattern after the ashing step.

As the substrate on which the metal layer is formed, aluminum (Al); aluminum-silicon (Al-Si),
Aluminum alloy (Al alloy) such as aluminum-silicon-copper (Al-Si-Cu); pure titanium (Ti); titanium nitride (TiN), titanium tungsten (Ti)
A substrate on which a metal film such as a titanium alloy (Ti alloy) such as W) or copper (Cu) is formed. The peeling method of the present invention is particularly applicable to a substrate having at least a pure titanium (Ti) layer as a metal layer, for example, a first titanium nitride (TiN) layer on a substrate, and then a second layer on the first layer. A substrate formed by forming a pure titanium (Ti) layer, an Al-Si-Cu layer as a third layer on the second layer, and a TiN layer as a fourth layer on the third layer. In this case, the pure titanium (Ti) has an effect of being extremely excellent in a corrosion prevention effect.

Coating, drying, exposure, development, etching and ashing are all conventional means and are not particularly limited. The etching may be either wet etching or dry etching, or a combination of both. Ashing is originally a method of removing a resist pattern. However, ashing often leaves a resist pattern partially as a deteriorated film, and the present invention is effective in completely removing the deteriorated film in such a case.

The developing step (III), (V)
Alternatively, after the peeling step (VI), a rinsing process and a drying process using commonly used pure water or lower alcohol may be performed.

Depending on the type of photoresist, a post-exposure bake, which is a post-exposure bake usually performed on a chemically amplified photoresist, may be performed. Further, post baking after forming the resist pattern may be performed.

The release treatment is usually performed by a dipping method or a spray method. The temperature of the stripping solution at that time is usually 50 to
Although performed at 85 ° C., the stripping method using the stripping solution composition of the present invention has a high effect of preventing corrosion of a metal film even at a high temperature of 75 to 85 ° C., and is excellent in strippability of a photoresist film and a deteriorated film. The peeling time is not particularly limited as long as it is a sufficient time for peeling, and is usually about 10 to 20 minutes.

[0043]

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

(Examples 1 to 5, Comparative Examples 1 to 5) A TiN layer as a first layer, a pure titanium (Ti) layer as a second layer, and an Al—Si—C layer as a third layer are sequentially formed on a silicon wafer.
On a substrate having a TiN layer as a fourth layer, a u-layer is coated with THMR-iP3300 (manufactured by Tokyo Ohka Kogyo Co., Ltd.), which is a positive photoresist made of a naphthoquinonediazide compound and a novolak resin, using a spinner, and heated to 90 ° C. 9
Prebake was performed for 0 second to form a photoresist layer having a thickness of 2.0 μm. This photoresist layer was coated with NSR-20.
Exposure was performed using a 05i10D (manufactured by Nikon Corporation) through a mask pattern, and development was performed with a 2.38% by weight aqueous solution of tetramethylammonium hydroxide (TMAH) to form a resist pattern. Next, post-baking was performed at 120 ° C. for 90 seconds.

[Removability Test of Photoresist Film] Next, a silicon wafer having a resist pattern formed under the above conditions was subjected to dry etching. This was immersed in a stripping solution composition of each composition shown in Table 1 at 80 ° C. for 20 minutes to perform a photoresist film stripping process. The substrate after the peeling treatment is sufficiently rinsed with pure water, and the peelability of the photoresist film and the state of corrosion of the first to fourth metal film layers are evaluated by observing SEM (scanning electron microscope) photographs. did. Table 1 shows the results. Note that all of the TiN in the first and fourth layers did not corrode, so the description in Table 1 was omitted.

[Removability test of deteriorated film] A resist pattern was formed and a silicon wafer was dry-etched by the same operation as in the photoresist film releasability test.

Next, the resist pattern was subjected to plasma ashing by an ashing apparatus “TCA-3822” (manufactured by Tokyo Ohka Kogyo Co., Ltd.) with oxygen gas at 150 ° C. for 60 seconds, but an ashing residue (altered film) was found. Was.

Subsequently, the treated silicon wafer was immersed in a stripping solution composition of each composition shown in Table 1 at 80 ° C. for 20 minutes, and a deteriorated film stripping process was performed. The substrate after the peeling treatment is sufficiently rinsed with pure water, and the peeled state of the deteriorated film and the corrosion state of the first to fourth metal film layers are evaluated by observing SEM (scanning electron microscope) photographs. did. Table 1 shows the results. The first and fourth layers of Ti
For N, there was no corrosion, so the description in Table 1 was omitted.

The peelability of the photoresist film and the deteriorated film was evaluated as follows.

◎: Good peelability ：: Some residue remained △: Many residue left The state of corrosion was evaluated as follows.

◎: Almost no corrosion ○: Slight corrosion was observed △: Considerable corrosion was observed

[0052]

[Table 1]

[0053]

As described above in detail, according to the present invention, even under a high temperature stripping condition, a photoresist film and a deteriorated film formed by processing such as dry etching, ashing and ion implantation under more severe conditions are used. Provided is a photoresist stripping solution composition excellent in both stripping properties and excellent in corrosion prevention effect on both a substrate on which Al or an Al alloy is formed or a substrate on which Ti is formed, and a photoresist stripping method using the same. can do.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Seiichi Kobayashi F-term (reference) 2H096 AA25 CA14 DA01 EA02 GA09 HA01 HA23 LA03 LA07 5F046 MA02 MA03 MA12 in Tokyo Metropolitan Chemical Industry Co., Ltd. 150 Nakamaruko, Nakahara-ku, Kawasaki

Claims (8)

[Claims] 1. (a) 2 to 30% by weight of hydroxylamines, (b) 2 to 35% by weight of water, (c) 25 to 40% by weight of monoethanolamine and / or 2- (2-aminoethoxy) ethanol And (d) 20 to 32% by weight of N-methyl-2-pyrrolidone and / or diethylene glycol monobutyl ether, and (e) 2 to 20% by weight of an aromatic hydroxy compound. 2. The method according to claim 1, wherein component (a) is hydroxylamine (NH).
_2. The photoresist stripper composition according to claim 1, which is ₂ OH). 3. The method according to claim 1, wherein the component (e) is catechol and / or tert-butyl catechol.
The stripping solution composition for a resist according to the above. 4. The photoresist stripping solution according to claim 1, wherein the photoresist is stripped on a substrate provided with a metal layer having at least a pure titanium (Ti) layer. Use of the composition. 5. A step of providing a photoresist layer on a substrate on which a metal layer has been formed, a step of selectively exposing the photoresist layer, and a step of developing the photoresist layer after exposure to form a resist pattern. Providing (IV)
The photoresist stripping solution according to any one of claims 1 to 3, wherein the photoresist stripping method comprises a step of etching the substrate using the resist pattern as a mask, and (V) a step of stripping the etched resist pattern from the substrate. A photoresist stripping method, wherein the resist pattern after etching is stripped using the composition at a temperature of 75 to 85 ° C. 6. The photoresist stripping method according to claim 5, wherein the metal layer has at least a pure titanium (Ti) layer. 7. A step of providing a photoresist layer on a substrate on which a metal layer is formed, a step of selectively exposing the photoresist layer, and a step of developing the photoresist layer after exposure to form a resist pattern. Providing (IV)
4. A photoresist stripping method comprising the steps of: etching the substrate using the resist pattern as a mask; (V) ashing the resist pattern; and (VI) stripping the resist pattern after the ashing from the substrate. A resist stripping method, wherein the resist pattern after ashing is stripped by using the photoresist stripping composition according to any one of the above items in a temperature range of 75 to 85 ° C. 8. The method according to claim 7, wherein the metal layer has at least a pure titanium (Ti) layer.