JPH08320552A - Resin composition, lower layer material and production of resist image - Google Patents

Abstract

PURPOSE: To obtain a resin compsn. having high safety to the human body and satisfactory appliability to a substrate when used for a multilayered resist, to obtain a lower layer material for forming a resist image on a coating film of the compsn. and to produce a resist image using the lower layer material. CONSTITUTION: The objective resin compsn. contains a resin having benzene rings, a compd. having an azido group on a benzene ring and propyleneglycolmonoalkyl ether propionate as a solvent. The objective lower layer material is used for forming a resist image made from the resin compsn. A layer of the lower layer material is formed, a layer of a resist material is formed on the lower layer and the objective resist image is formed by etching.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition, a resist forming lower layer material using the resin composition and a method for producing a resist image. More specifically, the coatability when applied to a substrate is improved. The present invention relates to a resin composition, a lower layer material for forming a resist using the resin composition, and a method for producing a resist image using the lower layer material.

[0002]

2. Description of the Related Art Conventionally, a photosensitive resin composition has a novolac resin containing phenol or cresol as a positive type monomer, 1,2-naphthoquinone- (2) -diazide-4 or 5-sulfonyl chloride, and poly (vinyl chloride). An ester photosensitizer with a compound having a hydroxyl group such as hydroxybenzophenone, naphthol, and gallic acid ester is used.

Further, as a solvent for the above-mentioned positive type photosensitive resin composition, 2-ethoxyethyl acetate or a mixed solvent of 2-ethoxyethyl acetate, xylene and butyl acetate is used. Further, recently, an example using 3-octanone is JP-A-4-29146, and an example using a monooxycarboxylic acid ester is JP-B-3-22619.
An example using a mixed solvent is described in JP-A-5-34919.

On the other hand, recently, the safety of the solvent used for the photosensitive resin to the human body is regarded as a problem, and reduction of the use of the above-mentioned ethylene glycol solvent such as 2-ethoxyethyl acetate or ethylene glycol alkyl ether is beginning to be desired. .

By the way, semiconductor devices are becoming finer and finer in order to achieve higher performance, and the line width of the semiconductor devices is becoming 0.5 micron or less at the latest state. On the other hand, the semiconductor device has a complicated structure due to the above-described miniaturization and high integration, and thus the step difference of the substrate is large. Further, the film to be processed includes a silicon oxide film, a silicon nitride film, aluminum, polysilicon, tungsten, etc., and when processing a film having a high light reflectance, reflected light is generated from the substrate during exposure,
There is a problem that a resist image as a mask cannot be obtained due to excessive exposure. For this reason, although there is a problem that the number of steps is increased when manufacturing a semiconductor device, a multilayer resist is proposed and described in Japanese Patent Publication No. 4-77899.

In the multi-layer resist for obtaining such a fine resist line width, a material having good coatability on the substrate is desired.

[0007]

DISCLOSURE OF THE INVENTION The present invention is highly safe to the human body when used in a multilayer resist, and
TECHNICAL FIELD The present invention relates to a resin composition having good coatability on a substrate, a lower layer material for forming a resist image on a coating film made of this composition, and a method for using the coating film used in a method for producing a resist image using the lower layer material. .

[0008]

The resin composition of the present invention comprises (A) a resin having a benzene ring, (B) a compound having an azide group on the benzene ring, and (C) a propylene glycol monoalkyl ether propio as a solvent. Nate. The lower layer material made of this resin composition is for forming a resist image, and the resin composition is applied onto a substrate and dried to form a coating film. An image made of a photoresist material is formed on this coating film, and a resist image is formed by etching. In this case, it is preferable to form a film resistant to oxygen gas on the film made of the lower layer material.

As the resin having a benzene ring, polystyrene, iodinated polystyrene, styrene resin such as chloromethylated polystyrene, polyhydroxystyrene,
There are novolac resins obtained by condensing phenols and aldehydes. In particular, novolac resins obtained by condensing phenols and aldehydes are preferable. Examples of phenols include phenol, cresol, xylenol, trimethylphenol, butylphenol, naphthol, resorcinol, catechol, and pyrogallol.
These can be used alone or in combination of two or more. Formaldehyde, paraformaldehyde, etc. are used as aldehydes. For the novolac resin synthesis catalyst, hydrochloric acid, oxalic acid, etc. are used.
After reacting at a temperature of 0 to 120 ° C. for several hours, it is heated under reduced pressure to remove water and unreacted phenols.

Examples of the compound having an azido group on the benzene ring include 4,4-diazidostilbene-2,2-disulfonic acid ethoxyethylamine, 1- (4azidobenzylidene) -3- (4-azide, α-hydroxybenzyl. ) Indene, 2,6-bis- (4-azidobenzylidene)-
4-t-amylcyclohexanone or the like is used. In terms of solubility in a solvent, 4,4-diazidostilbene-2,2-disulfonic acid ethoxyethylamine, 1-
(4-azidobenzylidene) -3- (4-azido-α-
Hydroxybenzyl) indene is preferred.

The resin composition according to the present invention contains propylene glycol monoalkyl ether propione as a solvent.
Are used. Propylene glycol monoalkyl ether propionate enhances the coating property of the resin composition on the substrate and dissolves the above compounds well. Therefore, this solvent enhances the coating property on the substrate and the resin composition has excellent storage stability. You can get things. The alkyl group of propylene glycol monoalkyl ether propionate is preferably a methyl group or an ethyl group.

[0012] Propylene glycol monomethyl ether propionate has low acute toxicity compared to 2-ethoxyethyl acetate, LD ₅₀ of propylene glycol monomethyl ether propionate, at 12,000 / kg (rat) or, acetate 2- The LD ₅₀ of ethoxyethyl is 2,
It is 900 mg / kg (rat). LD of propylene glycol monomethyl ether acetate with similar structure
₅₀ is 8,500-10,000 mg / kg (rat). The LD ₅₀ of cyclohexanone is 1,500 mg / kg
(Rats), LD ₅₀ of ethyl lactate, 5,000 mg / kg
(Rats), LD ₅₀ of acetic Isoarumi is 16,600
mg / kg (rat), heptanone of the LD ₅₀ is, 1,670m
It is g / kg (rat).

The solvent of the present invention may be mixed with another solvent for the purpose of improving the solubility of the compound.
Examples of other solvents include ketones, diketones, esters, and the like, examples of ketones include acetone, methyl ethyl ketone, and methyl isobutyl ketone, and examples of diketones include 2,3-butanedione and 2,4-pentanedione. Examples of the ester include ethyl acetate, butyl acetate and isoamyl acetate.

The proportion of propylene glycol monoalkyl ether propionate and other solvent used is propylene glycol monoalkyl ether propionate / other solvent = 100/0 to 50/50 (parts by weight), preferably It is 100/0 to 70/30 (parts by weight), and more preferably 100/0 to 90/10 (parts by weight).

The preferred ratio of the (A) benzene ring-containing resin and the (B) benzene ring-containing azido group-containing compound is (B) based on 100 parts by weight of the (A) benzene ring-containing resin based on the light absorption of the coating film. ) The amount of the compound having an azido group on the benzene ring is preferably 5 to 50 parts by weight, more preferably 10 to 50 parts by weight.
The propylene glycol monoalkyl ether propionate (C) is preferably used in an amount of 200 to 1000 parts by weight based on 100 parts by weight of the resin (A) having a benzene ring.

The lower layer material according to the present invention is applied onto a substrate, dried and cured to form a coating film. The application is usually performed by rotation, roll or the like. The dry curing is preferably performed at 100 to 300 ° C, more preferably 150 to 250 ° C. The dry-curing time is preferably 1 to 60 minutes. Dry curing is performed by a usual method such as a hot plate and an oven. If the temperature is too low during the drying and curing, it is difficult to color it to the extent that sufficient light absorption is imparted, and if the temperature is too high, the film deteriorates.

It is preferable to form a film resistant to oxygen gas after drying and curing. As this film, there are coating type silica liquid, silicon by a sputtering method, aluminum and the like.

Next, in order to form a resist image, a resist material such as photoresist or electron beam resist is further applied and dried on the uppermost layer to form a coating film. As the photoresist, for example, a positive-type photosensitive resin composition comprising the above-mentioned novolac resin and a photosensitizer of an ester of 1,2-naphthoquinone- (2) -diazide-4 or 5-sulfonyl chloride and polyhydroxybenzophenone is used. Available.
As the electron beam resist, it is preferable to use a novolac resin as the resin in terms of dry etching resistance, and RE-5000P manufactured by Hitachi Chemical Co., Ltd. or the like is used.

After exposing and developing these resists, a resist image is obtained, and then the silica film, silicon film, and aluminum film are etched.

Finally, the lower layer material according to the present invention is usually etched with oxygen gas using the mask of the silica film, the silicon film and the aluminum film prepared above to obtain an image of the desired lower layer material to complete a resist image.

On the other hand, a resist resistant to oxygen gas has a function of forming an image and resistance to oxygen gas, and a single layer film can be formed on the lower layer material, and the process can be simplified. For example, RU-1600P manufactured by Hitachi Chemical Co., Ltd. can be used.

As the substrate, silicon, aluminum,
Examples include glass, quartz, chrome, and chrome oxide.

The photosensitive resin composition of the present invention may contain auxiliary components depending on the purpose. Examples of these include a thermal polymerization inhibitor for achieving storage stability, a surfactant for making the coating film thickness uniform, and an adhesion improver for improving the adhesion to the substrate.

[0024]

EXAMPLES The present invention will be described in detail below with reference to examples. (1) Synthesis of Compound (1) The compound (1) 1- (4-azidobenzylidene) -3- (4-azido-α-hydroxybenzyl) indene having the structure of the following chemical formula 1 was synthesized under the following conditions. Inden 3
3 parts by weight and 82 parts by weight of 4-azidobenzaldehyde are dissolved in 400 parts by weight of methanol, and 30 parts by weight of a 10% by weight sodium hydroxide methanol solution prepared in advance is added, and the mixture is reacted at room temperature for 10 hours to precipitate. I got a thing. The precipitate was separated by filtration, added with methanol, washed, and vacuum dried. Then, the crystals were recrystallized from methylene chloride, the crystals were separated by filtration, methanol was added, the crystals were washed again, and vacuum dried to obtain the desired compound (1).

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(2) Example of resin synthesis In a 500 ml flask, 55 g of m-cresol and 45 g of p-cresol, 52.54 g of 37% aqueous formalin solution,
0.42 g of oxalic acid was charged and reacted at 95 ° C for 3 hours.
Next, reflux dehydration is performed at 105 ° C. for 1 hour, and then 180 °
After unreacted cresol was collected and removed by reducing the pressure to 10 mmHg at 1 ° C for 1 hour, it was opened in a vat and metaparacresol novolac resin (polystyrene-converted weight average molecular weight = 1
10,000) was obtained.

Example 1 90 g of metaparacresol novolac resin obtained in the above resin synthesis example, 18 g of compound (1), and 0.1 g of a surfactant (manufactured by Sumitomo 3M Ltd .; product name FC-431) were added to propylene glycol monomethyl ether. Propionate 270
After being dissolved in g, the mixture was filtered through a membrane filter having a pore size of 0.2 μm to obtain a resin composition. The composition obtained is
Spin coating at 3000 rpm on a silicon substrate treated with MDS (hexamethyldisilazane), 200 ° C., 120
It was dried for 2 seconds on a hot plate and cured to obtain a coating film having a thickness of 1.5 μm. At the time of coating, the wet spreadability of the resin composition on a silicon substrate was good.

Comparative Example 1 A resin composition was obtained in the same manner as in Example 1 except that cyclohexanone was used instead of propylene glycol monomethyl ether propionate. The obtained composition was applied, dried and cured in the same manner as in Example 1 to give 1.5 μm.
Although a film thickness of m was obtained, the wettability and spreadability on the silicon substrate was
It was not good as compared with Example 1.

Example 2 Metaparacresol novolac resin 9 used in Example 1
Example 1 1 g of 0 g, 27 g of azidostilbene type photosensitizer (product name DAZST51) manufactured by Toyo Gosei Co., Ltd., and 0.1 g of surfactant (product name FC-431 manufactured by Sumitomo 3M Ltd.)
It was dissolved in 280 g of propylene glycol monomethyl ether propionate used in 1. and filtered through a membrane filter having a pore size of 0.2 μm to obtain a resin composition. The obtained composition was spin-coated at 3000 rpm on a silicon substrate treated with HMDS (hexamethyldisilazane),
1.5 hours after drying and curing on a hot plate for 120 seconds at ℃
A coating film having a thickness of μm was obtained. At the time of coating, the wet spreadability of the resin composition on a silicon substrate was good.

Example 3 The metaparacresol novolak resin used in Example 1 was replaced with polyhydroxystyrene (Maruzen Petrochemical Co., Ltd.).
Product: Product name Linker M, polystyrene equivalent molecular weight = 5,2
A resin was obtained in the same manner as in Example 1 except that
As in Example 1, the wettability and spreadability on the silicon substrate was found to be good.

Example 4 Metaparacresol novolac resin 9 used in Example 1
0 g, compound (1) 15 g, compound (2) 3 of the following chemical formula 2
g, surfactant (Sumitomo 3M Co., Ltd .; product name FC-4
31) 0.1 g was dissolved in 270 g of propylene glycol monomethyl ether propionate, and then the pore size was adjusted to 0.
A resin composition was obtained by filtering through a 2 μm membrane filter. The obtained composition was spin coated on a silicon substrate treated with HMDS (hexamethyldisilazane) at 3000 rpm and dried at 200 ° C. for 120 seconds on a hot plate,
It was cured to obtain a coating film having a thickness of 1.5 μm. At the time of coating, the wet spreadability of the resin composition on a silicon substrate was good.

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Comparative Examples 2 to 4 10 g of the compound (1) was added to 100 g of each of the solvents shown in Table 1.
An attempt was made to dissolve it at room temperature, but none of them dissolved, and it was unsuitable as a solvent. It was dissolved in propylene glycol monomethyl ether propionate under the same conditions.

[Table 1]

Example 5 The resin composition (lower layer material) produced in Example 1 was applied onto a quartz substrate and dried and cured in an oven at 200 ° C. for 20 minutes to obtain a coating film. The light transmittance of this coating film at an exposure wavelength of 436 nm was measured by a spectrophotometer manufactured by Hitachi, Ltd., and it was 5% at a thickness of 1.5 μm. From this result, it was possible to confirm the light-shielding property capable of preventing the influence of the reflected light from the substrate during the exposure when forming the resist image.

Example 6 Resin composition (lower layer material) prepared in Example 1
It was applied on a silicon substrate with an aluminum film having a step of 5 μm, dried at 200 ° C. for 120 seconds on a hot plate and cured to obtain a 1.5 μm thick coating film. Next, a silica liquid (manufactured by Hitachi Chemical Co., Ltd .; product name H
SG) was applied, dried and cured on a hot plate at 200 ° C. for 120 seconds to form a silicon film. Further, a positive type photoresist (manufactured by Hitachi Chemical Co., Ltd .; product name RG-8018P-20) is applied at 4000 rpm on the resultant, and 1
It was dried on a hot plate at 10 ° C. for 60 seconds to obtain a coating film of 1 μm. Canon Inc. exposure equipment FPA1550
(Exposure wavelength; 436 nm, NA = 0.35), exposed through a photomask, and then 23 ° C. using a 2.38 wt% tetramethylammonium hydroxide aqueous solution.
It was developed for 60 seconds to obtain a resist image having a line width of 0.9 μm. When the pattern was observed, no influence of reflected light from the substrate was seen.

[0034]

The resin composition according to the present invention uses propylene glycol alkyl ether propionate as a solvent, so that it is safe for the human body, spreads well on the substrate, and forms a resist image on the substrate. Therefore, it can be widely used in fields such as the photographic industry, electronic industry, and printing industry. The lower layer material in claim 2 has the same effect as described above. By the method according to the third aspect, the resist can be produced in a safer method for the human body.

Claims (3)

[Claims] 1. A resin having (A) a benzene ring, (B)
A resin composition comprising a compound having an azido group on a benzene ring and (C) a propylene glycol monoalkyl ether propionate as a solvent. 2. An underlayer material for forming a resist image comprising the resin composition according to claim 1. 3. A resist image comprising forming a layer made of the lower layer material according to claim 2 on a substrate, forming a layer made of a resist material on the layer, and then forming a resist image by etching. Manufacturing method.