JPH1048818A - Positive type photoresist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a phtooresist compsn. excellent in a sensitivity, the depth of a focus and a heat resistance in a well-balanced state and capable of forming a resist pattern excellent in profile shape by using an compsn product of a specified polyhydroxy compd. with quinonediazidosulfonic acid as a photosensitive component. SOLUTION: This photoresist compsn. contains an alkali-soluble resin and a photosensitive component which is an esterified product of at least one of polyhydroxy compds. represented by formulae I, II with quinonediazidosulfonic acid. The alkalisoluble resin is, e.g. phenolic resin or acrylic resin known as the film forming resin of a positive type photoresist compsn. The photosensitive component is produced by dissolving prescribed amts. of at least one of polyhydroxy compds. represented by the formula I, II and quinonediazidosulfonic acid chloride in an org. solvent such as dioxane, adding a basic catalyst such as triethanolamine or triethylamine, bringing them into reaction, washing an drying the resultant reactional product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive photoresist composition, and more particularly, to a composition having a well-balanced sensitivity, depth of focus, and heat resistance required for manufacturing electronic components such as semiconductor devices and liquid crystal display devices. And a positive photoresist composition capable of forming a resist pattern having an excellent profile shape.

[0002]

2. Description of the Related Art Hitherto, in the manufacture of electronic components such as semiconductor devices such as ICs and LSIs and liquid crystal devices such as LCDs, a method of forming a pattern by photolithography has been employed. In the photolithography, a photoresist is applied on a substrate such as a silicon wafer or glass using a spinner or the like, dried, and then irradiated or drawn with an actinic ray or a particle beam through a mask to form a latent image. In this method, a pattern is formed on a substrate by developing. As a photoresist used in the photolithography, various resist compositions having excellent resolution have been developed and proposed. Among them, a positive photoresist composition containing an alkali-soluble novolak resin and a quinonediazide group-containing compound is preferable. The novolak resin is dissolved in an alkaline aqueous solution without swelling and has excellent developability,
Also shows excellent heat resistance to plasma etching. In addition, the quinonediazide group-containing compound itself has an action of suppressing the alkali solubility of the novolak resin. However, once, the quinonediazide group-containing compound may be an ultraviolet ray (g ray, i ray), an electromagnetic wave such as far ultraviolet ray including excimer laser, or the like. When irradiated with particle beams such as an electron beam or the like, the film changes to alkali-soluble and has a property of promoting the alkali-solubility of the novolak resin.

In recent years, it has been desired that photoresists used in the manufacture of ICs be excellent in various characteristics such as heat resistance, resolution, sensitivity, and profile shape. Positive photoresist compositions have been proposed. For example, US Pat.
77631, JP-A-62-35349,
JP-A-1-142548, JP-A-1-179914
No. 7, JP-B-3-4897, and the like.

[0004]

However, the positive photoresist composition described in the above-mentioned publication is characterized by the characteristics that meet the demands for miniaturization of semiconductor devices, which are increasing year by year, such as heat resistance, sensitivity, resolution, profile shape and the like. It is not enough and the improvement is strongly desired. As a resist composition corresponding thereto, for example, JP-A-4-328555
In the publication, photosensitive components are bis (2,3,6-trimethyl-4-hydroxyphenyl) -2-hydroxyphenylmethane and bis (2,3,6-trimethyl-4-hydroxyphenyl) -2,4-. Dihydroxyphenylmethane or bis (3,5-dimethyl-4-hydroxyphenyl)
A positive photoresist composition comprising naphthoquinone-1,2-diazidosulfonic acid ester of -3,4-dihydroxyphenylmethane is disclosed in Japanese Patent Application Laid-Open No. Hei 4-284454. Phenyl) -2-hydroxyphenylmethane, bis (2,5,
6-trimethyl-4-hydroxyphenyl) -2-hydroxyphenylmethane, bis (4,5-dimethyl-2-
A positive photoresist composition using a naphthoquinone-1,2-diazidesulfonic acid ester of (hydroxyphenyl) -2-hydroxyphenylmethane as a photosensitive component has been proposed. However, the positive photoresist composition is no longer sufficient in sensitivity, depth of focus characteristics, heat resistance, profile shape and the like.

In view of this situation, the present inventors have conducted intensive studies and as a result, in a positive photoresist composition containing an alkali-soluble resin and a photosensitive component, the photosensitive component was converted to a specific polyhydroxy compound and quinonediazide sulfonic acid. It has been found that a positive photoresist composition capable of forming a resist pattern excellent in sensitivity, depth of focus characteristics, and heat resistance in a well-balanced and excellent profile shape can be obtained by forming an esterified product with the above, and completed the present invention. Things.

That is, an object of the present invention is to provide a positive photoresist composition which can form a resist pattern excellent in sensitivity, depth of focus characteristics and heat resistance in a well-balanced and excellent profile shape.

[0007]

In order to achieve the above object, the present invention provides a positive photoresist composition containing an alkali-soluble resin and a photosensitive component, wherein the photosensitive component is represented by the following formulas (3) and (4). Polyhydroxy compound

[0008]

Embedded image

[0009]

Embedded image A positive photoresist composition characterized by being an esterified product of at least one member selected from the group consisting of quinonediazidesulfonic acid and quinonediazidesulfonic acid.

The alkali-soluble resin used in the present invention includes a phenolic resin, an acrylic resin, a copolymer of styrene and acrylic acid, and a polymer of hydroxystyrene, which are known as resins for forming a film of a positive photoresist composition. Coalescence, polyvinylphenol, poly-α-methylvinylphenol and the like. In particular, a phenol resin, particularly a novolak resin which easily dissolves in an aqueous alkali solution without swelling, has excellent developability, and has high stability against plasma used in dry etching is preferable. Examples of the phenolic resin include a condensation reaction product of a phenol and an aldehyde, a condensation reaction product of a phenol and a ketone, a vinylphenol-based polymer, an isopropenylphenol-based polymer, and a hydrogenation reaction of these phenolic resins. Products and the like. Phenols forming the phenol resin include phenol,
m-cresol, p-cresol, 2,5-xylenol, 2,3-xylenol, 2,6-xylenol,
Monohydric phenols such as 3,5-xylenol, 2,3,5-trimethylphenol, ethylphenol, propylphenol, butylphenol, and phenylphenol; polyhydric phenols such as resorcinol, pyrocatechol, hydroquinone, bisphenol A, and pyrogallol And the like. The aldehydes include formaldehyde, acetaldehyde, benzaldehyde, hydroxybenzaldehyde, terephthalaldehyde and the like, and the ketones include acetone, methyl ethyl ketone, diethyl ketone, diphenyl ketone and the like. One or a mixture of two or more of these compounds is reacted according to a conventional method in the presence of an acidic catalyst such as hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, formic acid or oxalic acid, and condensation of phenols with aldehydes is performed. Reaction products,
A phenol resin such as a condensation reaction product of a phenol and a ketone is produced. Among them, m-cresol, p
Novolak resins obtained by condensation of formaldehyde with several types of mixed phenols selected from phenols of cresol, 2,5-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol are preferred.

The above-mentioned vinylphenol-based polymer includes a homopolymer of vinylphenol and an acrylic acid derivative or methacrylic acid derivative copolymerizable with vinylphenol.
Styrene derivatives, maleic anhydride, vinyl acetate, selected from copolymers such as acrylonitrile, and the isopropenylphenol-based polymer is a homopolymer of isopropenylphenol and the above-described exemplified components copolymerizable with the isopropenylphenol. Selected from copolymers of Further, the hydrogenation reaction product of the phenol resin is produced by dissolving the phenol resin in an organic solvent and introducing hydrogen in a homogeneous or heterogeneous system in the presence of a hydrogenation catalyst.

The alkali-soluble resin used in the present invention comprises:
A resin having a weight-average molecular weight of 2,000 to 20,000, preferably 5,000 to 15,000 as measured by gel permeation chromatography is preferred. Particularly, a high-molecular-weight alkali from which low-molecular-weight components have been removed by fractionation or the like. Soluble resins are preferred. When the weight average molecular weight is less than 2,000, the film loss after development is large, and when it exceeds 20,000, the development speed is reduced.

In the present invention, the photosensitive component is a polyhydroxy compound represented by the following chemical formula (5) or (6).

[0014]

Embedded image

[0015]

Embedded image And quinonediazide sulfonic acid. By containing an esterified product of the polyhydroxy compound and quinonediazide sulfonic acid,
The positive resist composition of the present invention can form a resist pattern excellent in sensitivity, depth of focus characteristics and heat resistance in a well-balanced manner and excellent in profile shape. Examples of the quinonediazidesulfonic acid ester component include 1,2-naphthoquinonediazide-5 (or -4-)-sulfonic acid ester.

The photosensitive component is prepared by dissolving a predetermined amount of the polyhydroxy compound represented by the above formula (5) or (6) and quinonediazidesulfonic acid chloride in an organic solvent such as dioxane, N-methylpyrrolidone, dimethylacetamide, dimethylformamide and tetrahydrofuran. Then, a basic catalyst such as triethanolamine, triethylamine, pyridine, alkali carbonate, alkali hydrogen carbonate and the like is added thereto, and the mixture is reacted, washed with water, and dried.

In the positive photoresist composition of the present invention, naphthoquinone-1,2-diazidesulfonic acid ester known as a photosensitive component of the positive photoresist in addition to the above-mentioned photosensitive component is used in a range which does not impair the object of the present invention. May be used in appropriate combination. Examples of such known naphthoquinone-1,2-diazidosulfonic acid esters include 2,3,4-trihydroxybenzophenone, 2,3,4,4′-tetrahydroxybenzophenone, tris (4-hydroxy Phenyl) methane, bis (4-hydroxy-3,5-dimethylphenyl) -2-
Hydroxyphenylmethane, bis (4-hydroxy-
2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-
6-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-6-
Methylphenyl) -3,4-dihydroxyphenylmethane, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl)
Ethyl] benzene, 2- (2,3,4-trihydroxyphenyl) -2- (2 ′, 3 ′, 4′-trihydroxyphenyl) propane, bis (2,3,4-trihydroxyphenyl) methane And naphthoquinone-1,2-diazidosulfonic acid ester of a hydroxy compound.

The content of the photosensitive component of the present invention is in the range of 5 to 50 parts by weight, preferably 10 to 35 parts by weight, based on 100 parts by weight of the alkali-soluble resin. If the amount of the photosensitive component is less than 5 parts by weight, an image cannot be formed. If the amount exceeds 50 parts by weight, the resolution and the shape of the resist pattern are deteriorated, and the sensitivity is undesirably lowered.

In the positive photoresist composition of the present invention, in addition to the above-mentioned alkali-soluble resin and photosensitive component, a known low-molecular-weight phenol compound for improving sensitivity and resolution may be optionally added. An example of this low molecular weight phenol compound is Tris (4
-Hydroxyphenyl) methane, bis (4-hydroxy-3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (3-
Cyclohexyl-4-hydroxy-6-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl)-
3,4-dihydroxyphenylmethane, 1- [1- (4
-Hydroxyphenyl) isopropyl] -4- [1,1
-Bis (4-hydroxyphenyl) ethyl] benzene,
2- (2,3,4-trihydroxyphenyl) -2-
In addition to (2 ′, 3 ′, 4′-trihydroxyphenyl) propane, bis (2,3,4-trihydroxyphenyl) methane and the like, 2,6-bis [1- (2,4-dihydroxyphenyl) isopropyl ] -4-methylphenol, 2,6-bis (2,3,4-trihydroxyphenylmethyl) -4-methylphenol, 4,6-bis [1
-(4-hydroxyphenyl) isopropyl] -resorcinol. These low molecular weight phenol compounds can be blended in an amount of 5 to 50 parts by weight, preferably 10 to 35 parts by weight, based on 100 parts by weight of the alkali-soluble resin.

Further, if necessary, a compatible additive, an ultraviolet absorber for preventing halation, for example,
2,2 ', 4,4'-tetrahydroxybenzophenone, 4-dimethylamino-2', 4'-dihydroxybenzophenone, 5-amino-3-methyl-1-phenyl-4- (4-hydroxyphenylazo) pyrazole , 4
-Dimethylamino-4'-hydroxyazobenzene, 4
-Diethylamino-4'-ethoxyazobenzene, 4-
Diethylaminoazobenzene, curcumin and the like, and a surfactant for preventing striation, such as Florad FC-430, FC-431 (trade name, manufactured by 3M), F-top EF122A, EF122B, E
Fluorinated surfactants such as F122C and EF126 (trade name, manufactured by Tochem Products Co., Ltd.) can be added and contained as long as the object of the present invention is not hindered.

In using the positive photoresist composition of the present invention, it is preferable to use a coating solution dissolved in an organic solvent in the same manner as in the conventional resist pattern forming method of the photoresist technique. Examples of the organic solvent include acetone and Ketones such as methyl ethyl ketone, cyclohexane, methyl isoamyl ketone and 2-heptanone; ethylene glycol, propylene glycol, diethylene glycol, ethylene glycol monoacetate, propylene glycol monoacetate, diethylene glycol monoacetate or monomethyl ether, monoethyl ether, monopropyl thereof. Polyhydric alcohols such as ether, monobutyl ether or monophenyl ether and derivatives thereof; cyclic ethers such as dioxane; , Ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and the like esters such as ethyl ethoxypropionate.
One or more of these organic solvents can be used in combination. The coating solution prepared by dissolving in these solvents is applied to a substrate such as a silicon wafer or glass by an arbitrary coating method such as a spinner, dried and formed on a photosensitive layer, and then irradiated with radiation through a mask pattern. Exposure with a reduction projection exposure device, irradiation with excimer laser or X-ray, or irradiation while scanning electron beam,
It is immersed in a developing solution, for example, an alkaline aqueous solution such as an aqueous solution of 1 to 10% by weight of tetramethylammonium hydroxide, and a portion solubilized by exposure is selectively dissolved and removed to form an image faithful to the mask pattern.

The above-described pattern forming method is not limited to the processing of semiconductor devices and liquid crystal display devices, but is applied to the field of processing using lithography, for example, LCD, TAB, PC
B, chemical milling, printing, etc.

[0023]

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

The numerical values shown in Examples and Comparative Examples are numerical values according to the following measuring methods. (1) Sensitivity: A sample was applied on a silicon wafer using a spinner, and this was applied on a hot plate at 90 ° C. and 90 °
The resist film was dried for 1.0 second to form a resist film having a thickness of 1.05 μm, and the resist film was reduced to 0.1 to 0.1 μm using a reduction projection exposure apparatus NSR-2005i10D (manufactured by Nikon Corporation, NA = 0.57).
After exposure at 01 second intervals, PE at 110 ° C. for 90 seconds
B treatment, development with a 2.38% by weight aqueous solution of tetramethylammonium hydroxide for 65 seconds, washing with water for 35 seconds, and drying. The minimum exposure time at which the film thickness of the exposed portion after development becomes zero is defined as the sensitivity. A measuring method expressed in seconds (ms).

(2) Depth of focus width 1: Reduction projection exposure apparatus N
SR-2005i10D (manufactured by Nikon Corporation, NA = 0.5
Using 7), Eop (exposure amount required to form a 0.50 μm line and space one-to-one) is set as a reference exposure amount, and the focus at that exposure amount is shifted up and down as appropriate to expose and develop. And observing an SEM photograph of the obtained resist pattern, and setting the maximum value (μm) of defocus at which a rectangular resist pattern of 0.50 μm can be obtained to a depth of focus width of 1.

(3) Depth of focus width 2: A measuring method in which the maximum value (μm) of defocus at which a rectangular resist pattern of 0.40 μm is obtained in depth of focus width 1 is set to depth of focus width 2.

(4) Depth-of-focus width 3: A measuring method in which the maximum value (μm) of defocus at which a 0.38-micron rectangular resist pattern is obtained at the depth of focus of 1 is set to 3 in depth of focus.

(5) Heat resistance: A 5 μm resist pattern formed on a silicon wafer is heated from 125 ° C. to 5 ° C.
A method of measuring the minimum temperature at which the resist pattern is deformed when the temperature is increased and baked on a hot plate at each temperature for 5 minutes.

(6) Pattern shape: The cross-sectional shape of the resist pattern having a width of 0.35 μm obtained under the same conditions as in (1) was observed by an SEM (scanning electron microscope) photograph. , A slightly trapezoidal shape B
Measurement method.

Example 1 A mixture of m-cresol and p-cresol in a molar ratio of 4: 6 was condensed in a conventional manner with formalin using an oxalic acid catalyst to produce an alkali-soluble novolak resin having a weight average molecular weight of 8,000. did. The low molecular weight fraction of the novolak resin was removed to obtain a weight average molecular weight of 10,000. 100 parts by weight of the alkali-soluble novolak resin, a polyhydroxy compound represented by the following formula 7, and naphthoquinone-1,2-diazide-5-sulfonyl chloride
30 parts by weight of an esterified product with 5 mol
30 parts by weight of 5-dimethyl-4-hydroxyphenyl) -2-hydroxyphenylmethane were dissolved in a mixed solvent of 360 parts by weight of ethyl lactate and 40 parts by weight of butyl acetate, and the solution was filtered through a membrane filter having a pore size of 0.2 μm. A coating solution was prepared. The coating film formed using the prepared coating solution was measured by the measurement methods (1) to (6). Table 1 shows the results.

[0031]

Embedded image

Example 2 In Example 1, the photosensitive component was changed to an esterified product of 1 mol of a polyhydroxy compound represented by the following formula 8 and 2.5 mol of naphthoquinone-1,2-diazido-5-sulfonyl chloride. A coating solution was prepared in the same manner as in Example 1 except for the above. The coating film formed using the prepared coating solution was measured by the measurement methods (1) to (6). Table 1 shows the results.

[0033]

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Comparative Example 1 In Example 1, the photosensitive components were 1 mol of bis (4-hydroxy-2,3,6-trimethylphenyl) -3,4-dihydroxyphenylmethane and naphthoquinone-1,2-
A coating solution was prepared in the same manner as in Example 1, except that the esterified product with 2.5 mol of diazide-5-sulfonyl chloride was used. The coating film formed using the prepared coating solution was measured by the measurement methods (1) to (6). Table 1 shows the results.

Comparative Example 2 In Example 1, the photosensitive components were bis (4-hydroxy-2,3,6-trimethylphenyl) -2-hydroxyphenylmethane (1 mol) and naphthoquinone-1,2-diazido-5-sulfonyl. A coating solution was prepared in the same manner as in Example 1 except that the ester was changed to an esterified product with 2.5 mol of chloride. The coating film formed using the prepared coating solution was measured by the measurement methods (1) to (6). Table 1 shows the results.

Comparative Example 3 In Example 1, the photosensitive components were bis (4-hydroxy-2,3,5-trimethylphenyl) -2,4-dihydroxyphenylmethane (1 mol) and naphthoquinone-1,2-
A coating solution was prepared in the same manner as in Example 1, except that the esterified product with 2.5 mol of diazide-5-sulfonyl chloride was used. The coating film formed using the prepared coating solution was measured by the measurement methods (1) to (6). Table 1 shows the results.

Comparative Example 4 In Example 1, the photosensitive components were bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane (1 mol) and naphthoquinone-1,2-diazido-5-sulfonyl. A coating solution was prepared in the same manner as in Example 1 except that the ester was changed to an esterified product with 2.5 mol of chloride. The coating film formed using the prepared coating solution was measured by the measurement methods (1) to (8). Table 1 shows the results.

[0038]

[Table 1]

As shown in the above Table 1, the positive photoresist composition containing the photosensitive component of the present invention is excellent in sensitivity, depth of focus characteristics and heat resistance in a well-balanced manner and can form a resist pattern excellent in profile shape. I can see.

[0040]

As described above, the positive photoresist composition of the present invention comprises:
It can form a resist pattern excellent in sensitivity, depth of focus characteristics, and heat resistance in a well-balanced manner and excellent in profile shape, and is suitable for manufacturing semiconductor devices and liquid crystal display devices.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kosuke Doi 150 Nakamaruko, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Tokyo Keika Kogyo Co., Ltd. (72) Inventor Hidekatsu Ohara 150 Nakamaruko, Nakahara-ku, Kawasaki City, Kanagawa Prefecture (72) Inventor Toshimasa Nakayama 150 Nakamurako, Nakahara-ku, Kawasaki City, Kanagawa Prefecture

Claims (1)

[Claims] 1. A positive photoresist composition containing an alkali-soluble resin and a photosensitive component, wherein the photosensitive component is a polyhydroxy compound represented by the following chemical formulas 1 and 2. Embedded image A positive photoresist composition, which is an esterified product of at least one member selected from the group consisting of quinonediazidesulfonic acid.