JP2000171977A - Resist material and its preparation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist material having high sensitivity and resolution for a laser ray and having etching resistance for etching treatment, at the time of carring out pattern formation by using KrF eximer laser ray. SOLUTION: In this resist material, a protective group having a phenyl group and mole.wt. of 100-200 is combined with a base resin, and the protecting group and the base resin are combined with an ester linkage or an ether linkage. It is preferable that an acid-generator is contained in the resin material. And it is preferable that styrene system resin being used for the base resin contains hydroxy-styrene or hydroxy-styrene and acrylate as the resins.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist material having excellent etching resistance, and more particularly, to a resist material suitable for a fine processing operation using a short wavelength laser when forming a pattern using dry etching. The present invention relates to an amplification resist material.

[0002]

2. Description of the Related Art In recent years, the wavelength of lasers used in lithography technology has been shortened with high integration and miniaturization of semiconductor devices, and accordingly, the material of resist has been shortened. There is a demand for a material that can withstand the use of the above. For example, Kr is used as the short wavelength laser.
The use of an F excimer laser has been proposed, but the laser line having the high energy has a high sensitivity and a high resolution, and the pattern dimension has little change with time.
Development of a resist material having high dry etching resistance and excellent adhesion to a substrate is required.

[0003] Therefore, for example, Japanese Patent Application Laid-Open No.
Japanese Patent Application Publication No. JP-A-2005-17764 discloses a poorly alkali-soluble resin obtained by reacting a resin having a phenolic hydroxyl group with isopropenyl alkyl ether, 2-alkoxy-1-butene, isopropenylmethylsilyl ether or isopropenylbenzyl ether, and a photosensitive compound. A photoresist material containing the following has been proposed, and Japanese Patent Application Laid-Open Nos. Hei 8-21597 and Hei 9-160247 disclose a photoresist material having a molecular weight of 1;
A chemically amplified resist material containing a compound having a phenolic hydroxyl group of 00 to 1000 as a dissolution promoter has been proposed.

However, in any known technique,
In the pattern formation up to the pattern rule of 0.25 μm, use was possible.
For those of 5 μm or less, their use was difficult. When the KrF excimer laser is used to form a pattern with a fine pattern rule of 0.25 μm or less, for example, 0.18 μm or 0.15 μm, it is necessary to secure a depth of focus. In order to prevent the pattern from collapsing, it is essential to make the resist thinner and use an antireflection film.

In this case, there has been no problem until now, K
The dry etching resistance of the rF resist is particularly problematic. Here, as the resistance to dry etching, for example, an etching rate is employed as a measure of evaluation. When the resistance to dry etching is represented by the etching rate, the smaller the value of the etching rate, the better the resistance. Has been determined to be.

Here, the etching rate is generally defined as a value obtained by dividing the difference between the thickness of the resist before the dry etching and the thickness of the resist after the dry etching by the etching time. Have been. Therefore, in the conventional resist material, the etching rate is 2.0 or more, and it is determined that the etching resistance is not sufficient in such a state.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to improve the above-mentioned disadvantages of the prior art, and to manufacture a short-wavelength laser, particularly KrF
When a desired pattern is formed by dry etching using an excimer laser, a resist material having high sensitivity, high resolution to the laser, and etching resistance to dry etching is provided. is there.

[0008]

In order to achieve the above-mentioned object, the present invention employs the following basic technical structure. That is, a first aspect according to the present invention is a resist material in which a protecting group having a phenyl group is bonded to a base resin, and more specifically, the resist material having the phenyl group having a molecular weight of 100 to 200. This is a resist material in which the protective group and the base resin are bonded by an ester bond or an ether bond.

Further, as a second aspect of the present invention,
In producing a resist material in which a protective group having a molecular weight of 100 to 200 having a phenyl group is bonded to a base resin, a method for producing a resist material in which, after polymerizing the base resin, the protective group having a phenyl group is added. is there.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The resist composition according to the present invention employs the above-mentioned technical constitution. For example, an appropriate acid generator and an N-propylphenylcarboxyl group-protected type as shown in FIG. When a pattern is formed using a KrF excimer laser by using a polyhydroxystyrene resin (protection ratio: 40%), the laser has high sensitivity, high resolution, and is resistant to dry etching. Thus, a resist material having etching resistance can be obtained.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a specific example of the resist material according to the present invention will be described below in detail with reference to chemical formulas. That is, the resist material according to the present invention is a resist material in which a protective group having a phenyl group is bonded to a base resin, and the protective group and the base resin are bonded by an ester bond or an ether bond. desirable.

The molecular weight of the protecting group according to the present invention is not particularly limited, but it is preferable that the molecular weight is practically 100 to 200. Preferably contains an appropriate acid generator. The acid generator is not particularly limited, and a commonly used acid generator can be used.

On the other hand, in the present invention, the base resin preferably contains a styrene resin, and the base resin is preferably, for example, a hydroxystyrene resin. Further, another specific example of the base resin in the present invention may be, for example, a resin containing hydroxystyrene and acrylate.

On the other hand, the protecting group having a phenyl group used in the present invention is selected from the group consisting of N-propylphenylcarboxyl, ethoxyethylphenyl, N-propylphenyl and t-butoxyl. It is desirable to be composed of a single compound. In the present invention, the above-mentioned resist material is particularly preferably K
It is suitable as a chemically amplified resist material in a dry etching process using an rF excimer laser.

That is, in the present invention, the above-mentioned short-wavelength laser, especially a KrF excimer laser (having a wavelength of 24
In the dry etching process using 8 nm), a resist material that can prevent the solubility to an etching gas, exhibit excellent resistance to a fine patterning process, and can be patterned with high sensitivity has been obtained. It has been found that it is preferable to use a compound having a benzene nucleus for the substrate.

The compound having such a benzene nucleus is
It has been found that it is excellent in the transmittance of the rF excimer laser and has an effect of reducing the etching rate. Further, as a specific example of the method for producing the resist material according to the present invention, a molecular weight of 100 to 2 having a phenyl group is used.
In producing a resist material having a protective group of 00 bonded to the base resin, after polymerizing the base resin,
The present invention relates to a method for producing a resist material in which a protective group having a phenyl group is added, and as another specific example, a method for producing a resist material in which a protective group having a molecular weight of 100 to 200 having a phenyl group is bonded to a base resin. In doing so, a method for producing a resist material configured to add a monomer comprising a protective group having a phenyl group and a base resin and a monomer comprising a base resin having no protective group having a phenyl group and a base resin. is there.

Hereinafter, specific examples of the constitution of the resist material according to the present invention will be described in detail in the form of examples. [Embodiment 1] A resist material used in the embodiment 1 of the present invention comprises an acid generator and an N-type compound represented by the general formula (1).
It is composed of a propylphenyl carboxyl group-protected polyhydroxystyrene resin (protection rate: 40%).

In the method of manufacturing the resist material in the embodiment 1, for example, a protecting group having an N-propylphenylcarboxyl group is added after polymerizing hydroxystyrene as shown in the general formula (2). Or a method of polymerizing a hydroxystyrene monomer having the protective group with a hydroxystyrene monomer having no protective group.

[0019]

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[0020]

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In the method of evaluating the etching rate of the resist material according to the present invention, an etching rate value obtained by a standard etching rate measuring method described below is used as a reference and expressed as a ratio.
That is, the standard etching rate measuring method is that a laser is used by using Cl ₂ as an etching gas and a novolak resin as shown in the general formula (3) which is a conventional standard resist material. The etching rate when etching was performed using a line was measured.

[0022]

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The method of calculating the etching rate value is as described above. Then, as a result of calculating the ratio to the etching rate when dry etching was performed by a KrF excimer laser using the resist material manufactured in the above specific example, an etching rate ratio of 1.3 was obtained. Was. That is, in this specific example, the ratio when the etching rate in the standard resist material is set to 1 is shown. Ideally, the ratio is 1; Is aimed at approaching 1 as much as possible.

Therefore, in the above-mentioned specific example 1, taking into account that the etching rate ratio is 2.0 or more as described above in the prior art, it is a great improvement. As Comparative Example 1, as compared to the above specific example 1, a polyhydroxystyrene resin as shown in the general formula 4 using a t-butoxycarbonyl group having no phenyl group as a protecting group in the same base resin as the above specific example 1 (Protection ratio: 40%), and the etching rate of the resist constituted by using the same amount of the acid generator in Example 1 was 2.0.

Accordingly, it can be seen that the etching resistance of the resist of this example is improved as compared with the conventional case.

[0026]

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The resist film of Example 1 was formed on a silicon substrate, exposed through a mask with a KrF excimer laser beam under illumination conditions of a lens NA of 0.6, and developed to form a 0.16 μm line & space. On the other hand, a resist comprising a t-butoxycarbonyl group-protected polyhydroxystyrene resin having no phenyl group as a protective group (protection rate: 40%) and the same amount and the same amount of an acid generator as that used in Example 1 is 0%. Only 17 .mu.m line & space could be resolved.

Therefore, with the resist material according to the first embodiment, the etching resistance could be improved without deteriorating the resolution. [Embodiment 2] Next, a second embodiment of the present invention will be described below. The resist material in this specific example 2 is
An ethoxyethylphenyl group-protected type using an acid generator, an ethoxyethylphenyl group as shown in the general formula (5) as a protecting group, and a polyhydroxystyrene resin similar to that in the above specific example 1 as a base resin. Polyhydroxystyrene resin (protection rate: 40%) was used.

[0029]

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In the same manner as in the first embodiment, the resist material is formed by using Cl ₂ as an etching gas, and using a novolak resin as shown in the general formula (3) which is a conventional standard resist material. The ratio to the etching rate when etching was performed using the i-line, which is, was measured. As a result, in Example 2, the etching rate of the resist material was 1.4 with respect to the etching rate of the i-line resist mainly composed of novolak resin.

On the other hand, as Comparative Example 2, an ethoxyethyl group-protected polyhydroxystyrene resin having no phenyl group as a protective group represented by the general formula (6) (protection rate: 40)
%), The etching rate of the resist material formed by adding the same type and the same amount of acid generator as that of the specific example 2 is 2.1, and the etching resistance of the resist material of the specific example 2 is improved as compared with the conventional example. It turned out to be.

[0032]

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Further, a resist film of the resist material according to this example is formed on a silicon substrate, and a lens NA of 0.6 is formed.
Exposure was performed with a KrF excimer laser beam through a mask under the illumination conditions described above, followed by development to form a 0.16 μm line & space. On the other hand, a resist material comprising the same type and the same amount of an acid generator as used in Example 2 in a t-butoxycarbonyl group-protected polyhydroxystyrene resin having no phenyl group as a protective group (protection rate: 40%) 0.
A 16 μm line & space was resolved, and the etching resistance was able to be improved without deteriorating the resolution by the resist material of the specific example 2.

Embodiment 3 Next, a third embodiment of the resist material according to the present invention will be described. The resist material used in this specific example 3 is an acid generator, a general formula (7)
The N-propylphenyl group-protected polyhydroxystyrene resin using the same N-propylphenyl group as the protecting group and the same polyhydroxystyrene resin as in Example 1 above (protection rate) 4
0%).

[0035]

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In the same manner as in the first embodiment, the resist material is formed by using Cl ₂ as an etching gas, and using a novolak resin represented by the general formula (3) which is a conventional standard resist material. The ratio to the etching rate when etching was performed using the i-line, which is, was measured. As a result, in Example 3, the etching rate of the resist material was 1.3 relative to the etching rate of an i-line resist mainly composed of novolak resin.

On the other hand, as Comparative Example 3, a t-butoxyl group-protected polyhydroxystyrene resin having no phenyl group as a protective group represented by the general formula (8) (protection rate: 40)
%), The etching rate of the resist material formed by adding the same type and amount of acid generator as in Example 3 is 2.0, and the etching resistance of the resist material of Example 3 is improved as compared with the conventional example. It turned out to be.

[0038]

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Further, a resist film of the resist material according to this example is formed on a silicon substrate, and a lens NA of 0.6 is used.
Exposure was performed through a mask with a KrF excimer laser beam under the illumination conditions described above, followed by development to form a 0.17 μm line & space. On the other hand, a t-butoxylcarbonyl-protected polyhydroxystyrene resin using a t-butoxyl group having no phenyl group as a protecting group (protection rate: 40%) has the same amount and the same amount as that used in Example 3. The resist material composed of an acid generator resolved 0.17 μm lines and spaces, and the resist material of Example 3 could improve the etching resistance without deteriorating the resolving power.

[Embodiment 4] Next, a third embodiment of the resist material according to the present invention will be described. The resist material used in Example 4 uses an acid generator, an N-propylphenyl group as shown in the general formula (9) as a protecting group, and is the same as in Example 1 above. It is composed of an N-propylphenyl group-protected acrylate (35% protection) using a resin obtained by copolymerizing acrylate with polyhydroxystyrene as a base resin.

[0041]

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In the same manner as in the first embodiment, the resist material is formed by using Cl ₂ as an etching gas, and using a novolak resin represented by the general formula (3) which is a conventional standard resist material. The ratio to the etching rate when etching was performed using the i-line, which is, was measured. As a result, in Example 4, the etching rate of the resist material was 1.5 relative to the etching rate of an i-line resist mainly composed of novolak resin.

On the other hand, as Comparative Example 4, the general formula (1)
0-) A t-butoxyl group having no phenyl group is used as a protecting group as shown in 0), and a resin obtained by copolymerizing acrylate with polyhydroxystyrene is used as a base resin.
Propyl phenyl group protected acrylate resin (protection rate 3
5%) and the same amount and the same amount of acid generator as in Example 4 had an etching rate of 2.2, and the etching resistance of the resist material of Example 4 was lower than that of the conventional example. It was found to improve.

[0044]

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Further, a resist film of the resist material according to this example is formed on a silicon substrate, and a lens NA of 0.6 is used.
Exposure was performed through a mask with a KrF excimer laser beam under the illumination conditions described above, followed by development to form a 0.17 μm line & space. On the other hand, a resist material comprising the same kind and the same amount of an acid generator as used in Example 4 in a t-butoxylcarbonyl-protected polyhydroxystyrene resin having no phenyl group as a protecting group (protection rate: 40%) Resolved 0.17 μm line & space, and the resist material of Example 4 improved the etching resistance without deteriorating the resolution.

[0046]

Since the resist material according to the present invention employs the above-mentioned technical constitution, polymethyl methacrylate having a molecular weight of 15,000 when Cl ₂ is used as an etching gas (general formula (11)) Has an etching rate of 3.0, that of polyhydroxystyrene having the same molecular weight (general formula (12)) is 1.8, and that polyhydroxystyrene having a phenyl group has better etching resistance. There was found.

[0047]

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[0048]

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The etching rate is accelerated by the cleavage of the polymer chain by the etching gas. However, the carbon double bond is harder to be broken than the single bond, and the phenyl group comprising the carbon double bond is effective in improving the etching resistance. It can be said that there is. As described above, in the present invention, when manufacturing a highly integrated semiconductor device, when a desired pattern is formed by dry etching using a short-wavelength laser, particularly a KrF excimer laser, Thus, a resist material having high sensitivity, high resolution, and etching resistance to dry etching can be easily obtained.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H025 AA01 AA02 AA09 AB16 AC04 AC08 AD03 BE00 BE10 BJ10 CB14 CB16 CB17 CB41 CB45 CB55 FA41 4J100 AB07P AB07Q AL03Q AL08Q BA02Q BA04Q BA22Q BC43Q CA01 DA01 JA38

Claims (11)

[Claims] 1. A resist material comprising a protecting group having a phenyl group bonded to a base resin. 2. The resist material according to claim 1, wherein said protecting group and said base resin are bonded by an ester bond or an ether bond. 3. The resist material according to claim 1, wherein the resist material contains an acid generator. 4. The resist material according to claim 1, wherein the base resin contains a styrene-based resin. 5. The resist material according to claim 4, wherein said base resin contains hydroxystyrene. 6. The base resin according to claim 4, wherein said base resin contains hydroxystyrene and acrylate.
Or the resist material according to 5. 7. The protecting group having a phenyl group may be N-
7. The method according to claim 1, wherein the carboxylic acid is composed of one selected from the group consisting of a propylphenylcarboxyl group, an ethoxyethylphenyl group, an N-propylphenyl group, and a t-butoxyl group. Resist material. 8. The protective group having a phenyl group has a molecular weight of 100 to 200.
The resist material according to any one of the above. 9. The resist material according to claim 1, wherein the resist material is a chemically amplified resist material for a KrF excimer laser. 10. A molecular weight of 100 to 2 having a phenyl group.
In producing a resist material having a protective group of 00 bonded to the base resin, after polymerizing the base resin,
A method for producing a resist material, comprising adding the protective group having the phenyl group. 11. A phenyl group-containing molecular weight of 100-2.
In producing a resist material in which the protective group of No. 00 is bonded to the base resin, the resist material comprises a monomer comprising the protective group having a phenyl group and the base resin, and a base resin having no protective group having the phenyl group. A method for producing a resist material, comprising adding a monomer.