JPH04249509A - pattern forming material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a pattern forming material, and in particular, it is capable of obtaining patterns with good sensitivity, resolution and contrast when exposed to short wavelength light such as excimer laser or deep ultraviolet rays, and is resistant to etching. The present invention relates to a pattern forming material suitable as a resist material due to its excellent properties.

0002

2. Description of the Related Art As the degree of integration of semiconductor integrated circuits increases, there is a demand for finer line widths of circuit patterns formed by photolithography, and there is a need for photoresists that are compatible with exposure light of shorter wavelengths. For example, excimer laser (ArF: wavelength 193 nm, KrF: wavelength 2
There is a need for a photoresist that can be used for exposure to short wavelengths such as 49 nm, XeCl: wavelength 308 nm), and deep ultraviolet rays (hereinafter abbreviated as "DUV", wavelength 190 to 330 nm). Photoresists (hereinafter referred to as
DUV resists include positive types such as AZ2400 (trade name) and polymethyl methacrylate (PMMA), which are commercially available from Shipley, and negative types such as polyglycidyl methacrylate (PGMA) and chloromethylated styrene (DUV resists). CMS) etc. are known.

However, PMMA and PGMA have the drawbacks of poor dry etching resistance and very poor sensitivity. Furthermore, although CMS has a sensitivity about 10 times better than PMMA, it still has a wavelength of 249 nm at a film thickness of about 0.5 μm.
Approximately 1000-2000m for a nm KrF laser
J/cm2, which also has the drawback of poor sensitivity.

AZ2400 has good etching resistance and has the best sensitivity among conventional DUV resists (approximately 100 mJ/cm2 (film thickness approximately 1.0 μm) for KrF laser with a wavelength of 249 nm). )
. However, when AZ2400 is exposed to DUV light, the transmittance of the exposure light is low, and it is understood that the resist originally contains a large amount of components that absorb DUV light. Incidentally, FIG. 2 shows an ultraviolet spectral curve when a resist film made of AZ2400 with a film thickness of 1.5 μm is irradiated with a laser having a wavelength of 249 nm. As is clear from FIG. 2, AZ2400 has low transmittance in the far ultraviolet region, particularly around 249 nm. Therefore, it can be seen that even if a pattern is formed using exposure light having a wavelength of 249 nm using AZ2400, a resist pattern with good contrast cannot be obtained.

[0005] Therefore, a resin has been proposed in which an o-nitrobenzyl compound, which is a photoreceptor, is directly esterified with a styrene-maleic acid copolymer. (Unexamined Japanese Patent Publication No. 1-140
Publication No. 143)

[0006]

However, even the resin described in JP-A-1-140143 was still insufficient in etching resistance, sensitivity, resolution and contrast against excimer laser exposure.

As described above, when a resist pattern is formed using a conventional pattern forming material, the resulting resist pattern is not good. In some cases, it was not possible to obtain a good fine pattern.

Therefore, an object of the present invention is to obtain a pattern with good sensitivity, resolution, and contrast when exposed to short wavelength light such as DUV light, and to have excellent etching resistance, so that it is suitable as a resist material. An object of the present invention is to provide a pattern forming material.

[0009]

[Means for Solving the Problems] In order to solve the above problems, the present invention provides the following general formula (1):

0010

[C4]

[In the formula, R1 and R2 may be the same or different, and represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkoxy group, or an alkyl group containing a hydroxyl group, or a phenyl group, and the following formula ( 1-1) or (1-2):

0012

[C5]

(In formula (1-1) or (1-2), R3
is one selected from a hydrogen atom, an alkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, a halogen atom, or a nitro group, m is an integer from 0 to 5, and d is 1
PL is an integer of from The following formula (1-3) or (1-4) having a reactive double bond:

[0014]

[C6]

(In formula (1-3) or (1-4), R4 and R5 may be the same or different and are a hydrogen atom or an alkyl group, R6 is a hydrogen atom or a methyl group, and n is 1 is an integer of 5 to 5), where a and b are integers of 1 or more, and c is an integer of 0 or 1 or more. The object of the present invention is to provide a pattern-forming material containing a resin (I) made of a polymer containing at least one type of polymer, and a solvent.

[0016] PL in the above formula (1) is preferably indene.

In the formula (1), PL is (A) 70 to 99 parts by weight of indene, (B) 0.5 to 29 parts by weight of styrene.
5 parts by weight, and (C) 0.5 to 29.5 parts by weight of at least one selected from α-methylstyrene, methylstyrene, dimethylstyrene, trimethylstyrene, coumaron, methylindene, and dicyclopentadiene. It is preferable that it is a component.

The pattern forming material of the present invention will be explained in detail below.

In the general formula (1) representing the resin (I) which is the main component of the pattern forming material of the present invention, R1 and R2 may be the same or different, and represent a hydrogen atom, an alkyl group, an alkenyl group, or a hydroxyl group. an alkyl group or a phenyl group containing a group, and the above formula (1-
It is at least one kind selected from the groups represented by 1) or (1-2). Examples of the alkyl group for R1 or R2 include a methyl group, ethyl group, and propyl group, and examples of the cycloalkyl group include a cyclohexyl group. Examples of the alkyl group or phenyl group containing an alkoxy group or hydroxyl group include a butoxyethyl group, a butoxyethoxyethyl group, and the like. In addition, the above formula (1-1) or (1
In -2), R3 is one selected from a hydrogen atom, an alkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, a halogen atom, or a nitro group. This R3
Examples of the alkyl group include methyl group, ethyl group,
Examples of the alkoxy group include isopropyl group, etc.
Examples include methoxy group, ethoxy group, butoxy group, etc., and examples of the halogen atom include chlorine, bromine, fluorine, etc. n is an integer of 0 to 5, preferably an integer of 0 to 2, and d is an integer of 1 to 3, preferably an integer of 1 to 2. Moreover, at least a part of R1 and R2 is a group represented by the above formula (1-2).

PL is a mixture whose main component is a compound represented by the above formula (1-3) or (1-4) having a coal- or petroleum-based reactive double bond. The above formula (1-3
) or (1-4), R4 and R5 may be the same or different and are a hydrogen atom or an alkyl group, R6 is a hydrogen atom or a methyl group, and m is 1 to
It is an integer of 5. This PL is, for example, a mixture containing indene as a main component, and specifically, (A) indene 7
0 to 99 parts by weight, (B) 0.5 to 29.5 parts by weight of styrene, and (C) α-methylstyrene, methylstyrene, dimethylstyrene, trimethylstyrene, coumaron,
Examples include compositions containing 0.5 to 29.5 parts by weight of at least one selected from methylindene and dicyclopentadiene.

[0021] Furthermore, in the above formula (1), a and b
is an integer of 1 or more, preferably an integer of 10 to 30,
c is 0 or an integer of 1 or more, preferably an integer of 0 to 5.

The resin (I) used in the pattern forming material of the present invention has the following formula (2):

[0023]

[C7]

A copolymer of maleic anhydride and a polymeric component mainly composed of indene and/or its derivatives represented by PL, which has a repeating structural unit represented by
(hereinafter referred to as "IMA resin") and the following formula (3):

0
025]

[Chemical formula 8]

The acid anhydride group of the IMA resin is esterified with the o-nitrobenzyl compound by reacting it with the o-nitrobenzyl compound represented by the following formula. This resin (I) may be one in which all of the acid anhydride groups of the IMA resin are esterified with an o-nitrobenzyl compound, or a part thereof may be esterified with an o-nitrobenzyl compound.

As a specific example of the resin (I) represented by the above formula (1), a polymeric component represented by PL represented by the following formulas (4-1) and (4-2) and maleic anhydride are used. A copolymer with an acid (hereinafter referred to as "IMA resin") is reacted with an o-nitrobenzyl compound as a photoreceptor, and all of the acid anhydride groups of the IMA resin are esterified with the o-nitrobenzyl compound. There are many things that can be mentioned.

[0028]

[Chemical formula 9]

The solvent which is another essential component of the pattern forming material of the present invention is not particularly limited and may be any solvent as long as it can dissolve the resin (I). Examples include ethyl cellosolve acetate, methyl isobutyl ketone, diisobutyl ketone, dioxane, ethylene glycol dimethyl ether, diethylene glycol diethyl ether, and the like. These solvents are appropriately selected depending on the exposure light used so that contrast and resolution are good. For example, for light with a wavelength of 249 nm, ethylene glycol dimethyl ether,
Diethylene glycol diethyl ether and the like are preferred.

In the pattern forming material of the present invention, the blending ratio of the resin (I)/solvent is usually 1/1 by weight.
Approximately 0 to 5/10, preferably 2/10 to 4/1
It is about 0.

Furthermore, the pattern forming material of the present invention may contain, for example, a compound containing an SO2 Cl group in order to prevent unexposed areas from dissolving in alkali during development.

Furthermore, the patterning material of the present invention may also contain materials commonly contained in materials used in photoresists of this type to impart various properties.

The pattern forming material of the present invention can be produced by mixing predetermined amounts of the resin (I), a solvent, and, if necessary, other components.

In the pattern forming material of the present invention, the resin (I) contained reacts with the exposure light during exposure to form the following formula:

00
35]

[Chemical formula 10]

The photoreaction represented by the above formula (6) occurs, and since the reaction product represented by the above formula (6) contains carboxylic acid, it becomes soluble in an alkaline aqueous solution and is dissolved by development, resulting in a desired shape corresponding to a photomask etc. It is possible to form a positive image of a circuit pattern.

The pattern forming material of the present invention has a coating film thickness:
It has a diameter of 1.0 to 3.0 μm and is suitable for photolithography using a KrF excimer laser with a wavelength of around 249 nm.

[0038]

EXAMPLES The present invention will be specifically explained below with reference to Examples, but these Examples are not intended to limit the scope of the present invention in any way.

(Examples 1 to 6) In each example, the formula (
PL, a, b and c in 4-1), and the group R
1 were prepared as shown in Table 1, and 21 g of diethylene glycol dimethyl ether and 0.5 g of tosyl chloride were added to 5 g of each of these resins to obtain a pattern forming material.

[0040]

[Table 1]

Note: (A), (B) and (C) in Table 1
) is as shown below. (A): Indene (B): Styrene (C): At least one member selected from α-methylstyrene, methylstyrene, dimethylstyrene, trimethylstyrene, coumaron, methylindene, and dicyclopentadiene

Next, as shown in FIG. 1A, a pattern forming material was applied onto the semiconductor substrate 1 by spin coating to form a resist film 2 having a thickness of 1.5 μm. As shown in FIG. 1B, this resist film 2 was selectively irradiated with a KrF excimer laser 4 having a wavelength of 249 nm through a mask 3 for pulse exposure. Finally, an alkali development process was performed to dissolve and remove the exposed areas, thereby obtaining a resist pattern 5. The resist pattern 5 obtained as described above was a fine pattern (0.25 μm) with high precision and good contrast according to the mask used.

[0043]

Effects of the Invention The pattern forming material of the present invention has excellent sensitivity and
It is suitable as a resist material because a pattern with good resolution and contrast can be obtained and it has excellent etching resistance.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram illustrating the resist pattern forming process carried out in Examples 1 to 6.

FIG. 2 is an ultraviolet spectral curve when a resist film made of AZ2400 with a film thickness of 1.5 μm is irradiated with a laser having a wavelength of 249 nm.

[Explanation of symbols]

1 Semiconductor substrate, 2 Resist film, 3. Mask, 4 Excimer laser, 5 Resist pattern

Claims (3)

[Claims] [Claim 1] The following general formula (1): [In the formula, R1 and R2 may be the same or different and are a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkoxy group, or a hydroxyl group] an alkyl group or phenyl group containing, and the following formula (1
-1) or (1-2): [Formula (1-1) or (1-2), R3 is a hydrogen atom, an alkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, a halogen atom, or a nitro n is an integer of 0 to 5, d is an integer of 1 to 3), and at least a part of R1 and R2 is the above formula (1-2)
PL is a group represented by the following formula (1-3) or (1-4) having a coal- or petroleum-based reactive double bond.
: [Formula (1-3) or (1-4), R4 and R5 may be the same or different and are a hydrogen atom or an alkyl group, R6 is a hydrogen atom or a methyl group,
m is an integer of 1 to 5), a and b are integers of 1 or more, and c is 0.
or an integer of 1 or more], and a solvent. 2. The pattern forming material according to claim 1, wherein PL in the formula (1) is indene. [Claim 3] PL in the formula (1) is (A)
Indene 70-99 parts by weight, (B) styrene 0.5-2
9.5 parts by weight, and (C) α-methylstyrene, methylstyrene, dimethylstyrene, trimethylstyrene,
The pattern forming material according to claim 1, which is a polymeric component containing 0.5 to 29.5 parts by weight of at least one selected from coumaron, methylindene, and dicyclopentadiene.