JP5433999B2 - Manufacturing method of resin for photoresist - Google Patents

Description

  The present invention relates to a method for producing a photoresist resin. More specifically, the present invention relates to a method for producing a photoresist resin, which can improve the conversion rate of a monomer used as a resin raw material into a polymer.

  In the field of microfabrication represented by the manufacture of integrated circuit elements, lithography technology capable of finer processing is required to obtain a higher degree of integration. However, in the conventional lithography process, near ultraviolet rays such as i rays are generally used as radiation, and it is said that fine processing at the subquarter micron level is extremely difficult with this near ultraviolet rays. Therefore, for example, in order to enable fine processing at a level of 0.10 μm or less, use of radiation having a shorter wavelength is being studied. Examples of such short-wavelength radiation include an emission line spectrum of a mercury lamp, far-ultraviolet rays typified by an excimer laser, an X-ray, an electron beam, and the like. Among these, a KrF excimer laser (wavelength 248 nm) is particularly preferable. ) Or ArF excimer laser (wavelength 193 nm) has been attracting attention.

  Used for photolithography such as a radiation-sensitive resin composition for resist formation suitable for irradiation with such radiation, and a resin composition for forming an upper layer film or a lower layer film (antireflection film, etc.) in a multilayer resist. Many resin compositions have been proposed.

  And as a manufacturing method of the resin for photoresists used for such a resin composition, for example, a solution containing a polymerizable monomer and a solution containing a polymerization initiator are continuously or intermittently contained in the polymerization system. For example, there are known a method in which the polymer is supplied and polymerized (see Patent Documents 1 and 2), a method in which the polymerization is performed under reduced pressure and reflux conditions (see Patent Document 3), and the like.

JP 2004-269855 A JP 2003-246825 A JP 2005-60511 A

However, in the conventional method for producing a resist resin, the conversion rate of the monomer used as a resin raw material into a polymer is still not sufficient, and the remaining unreacted monomer causes the exposure characteristics of the final product to deteriorate. There is a risk of becoming. In particular, when a monomer having low solubility in a polymerization solvent such as a solid monomer is used, a large amount of solvent for dissolving the monomer is required, and the monomer concentration in the polymerization reaction cannot be sufficiently increased. The present situation is that the conversion rate of the monomer into the polymer is not sufficiently increased.
From the above, from the viewpoint of improving the performance and productivity of the obtained resin, there is a demand for a method for producing a resin for photoresist that can further increase the conversion rate of the monomer used as the resin raw material to the polymer. This is the current situation.

  An object of this invention is to provide the manufacturing method of the resin for photoresists which can improve the conversion rate to the polymer of the monomer used as a resin raw material.

The present invention is as follows.
[1] A method for producing a photoresist resin, which comprises producing a photoresist resin by polymerizing a polymerizable compound in the presence of a solvent,
The polymerizable compound is a monomer having an ethylenically unsaturated bond,
At least one of the polymerizable compounds is a solid compound at room temperature,
A method for producing a photoresist resin, wherein a solvent is distilled off during a polymerization reaction.
[2] The compound that is solid at room temperature includes 5-methacryloyloxy-2,6-norbornanecarbolactone, 2-ethyl-2-adamantyl methacrylate, 5-oxo-4-oxa-tricyclo [5.2.1. 0 ^3,8 ] dec-2-yl methacrylate, 3- (2-hydroxyethoxy) -1-adamantyl methacrylate, 2-isopropyl-2-adamantyl methacrylate, 2-[[(trifluoromethyl) sulfonyl] amino] ethyl methacrylate 1,2-cyclohexanedicarboxylic acid mono [2-[(2-methyl-1-oxo-2-propenyl) oxy] ethyl] ester, 5- [3,3,3-trifluoro-2-hydroxy-2- (Trifluoromethyl) propyl] bicyclo [2.2.1] heptan-2-ylmetac In the above [1], which is a rate or 6- [3,3,3-trifluoro-2-hydroxy-2- (trifluoromethyl) propyl] bicyclo [2.2.1] heptan-2-yl methacrylate The manufacturing method of resin for description of description.
[3] In the above [1] or [2], the amount of the solvent distilled off during the polymerization reaction is 25 to 65% by mass when the total amount of the solvent used in the polymerization is 100% by mass. The manufacturing method of resin for description of description.
[4] The method for producing a photoresist resin according to any one of [1] to [3], wherein the reaction solvent is distilled off continuously or intermittently.
[5] The above-mentioned [1] to [44], wherein the evaporation rate of the solvent during the polymerization reaction is 5 to 44% by mass / h when the initial total amount of the solvent used in the polymerization is 100% by mass. [4] The method for producing a photoresist resin according to any one of [4].
[6] The method for producing a photoresist resin according to any one of [1] to [5], wherein the polymerization reaction is performed under pressure.

  According to the method for producing a resin for a photoresist of the present invention, the solid content concentration (particularly the monomer concentration) in the polymerization solution is made higher than before by distilling off the solvent during the polymerization reaction (evaporation distillation). It can be maintained at a high concentration, that is, it can be polymerized in a state where the solid content is more concentrated than before, and the conversion rate of the monomer (monomer) used as a resin raw material to a polymer (polymer) is greatly increased. Can be improved. In addition, even when using solid monomers that have low solubility in the polymerization solvent and require a large amount of solvent for dissolving the monomer, the solid content concentration is maintained higher than the conventional concentration as described above. Since it can polymerize, the conversion rate to a polymer can be improved. Furthermore, by improving the conversion rate to polymer, a high-purity resin solution with a low content of impurities such as unreacted monomers that cause the exposure characteristics of the final product to deteriorate can be obtained. A resin can be obtained. Furthermore, the amount of expensive monomers required for polymerization can be reduced as compared with the conventional amount, and the productivity of the photoresist resin can be improved.

Hereinafter, the present invention will be described in detail.
The method for producing a photoresist resin of the present invention is a method for producing a photoresist resin by polymerizing a polymerizable compound in the presence of a solvent, and at least one of the polymerizable compounds is at room temperature. In which the solvent is distilled off during the polymerization reaction.

The polymerizable compound is a resin composition used for photolithography, such as a radiation-sensitive resin composition for resist formation, a resin composition for forming an upper layer film or a lower layer film (antireflection film, etc.) in a multilayer resist. a polymerizable compound having an ethylenically unsaturated bond used in the production of a photoresist resin contained in the (monomeric).

  Here, for example, the resin contained in the positive-type radiation-sensitive resin composition for resist formation is at least a repeating unit having a chemical structure that is decomposed by an acid and becomes soluble in an alkali developer, more specifically, And a repeating unit (1) having a chemical structure in which a non-polar substituent is dissociated by an acid and a polar group soluble in an alkali developer is expressed, and a polar group for enhancing adhesion to a substrate such as a semiconductor substrate The repeating unit (2) is an essential component, and includes a repeating unit (3) having a non-polar substituent for adjusting the solubility in a solvent or an alkali developer as necessary. .

  The repeating unit (1) that is decomposed by an acid and becomes alkali-soluble means a chemical structure generally used as a conventional resist, and a monomer having a chemical structure that is decomposed by an acid and becomes alkali-soluble. After polymerizing or polymerizing a monomer having an alkali-soluble chemical structure, the substituent having an alkali-soluble group (alkali-soluble group) in the alkali-soluble chemical structure is dissociated by an acid without being dissolved in the alkali. It can be obtained by protecting with a group (acid-dissociable protecting group).

Examples of the monomer having a chemical structure that becomes alkali-soluble when decomposed by an acid include compounds in which an acid-dissociable protecting group is bonded to a polymerizable compound containing an alkali-soluble substituent. And compounds having a phenolic hydroxyl group, a carboxyl group or a hydroxyfluoroalkyl group protected with an acid dissociable protecting group. Specifically, for example, hydroxystyrenes such as p-hydroxystyrene, m-hydroxystyrene, p-hydroxy-α-methylstyrene; acrylic acid, methacrylic acid, maleic acid, fumaric acid, α-trifluoromethylacrylic acid , 5-norbornene-2-carboxylic acid, 2-trifluoromethyl-5-norbornene-2-carboxylic acid, carboxytetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] carboxylic acids having an ethylenic double bond such as dodecyl methacrylate; p- (2-hydroxy-1,1,1,3,3,3-hexafluoro-2-propyl) styrene, 2- ( 4- (2-hydroxy-1,1,1,3,3,3-hexafluoro-2-propyl) cyclohexyl) -1,1,1,3,3,3-hexafluoropropyl acrylate, 2- (4 -(2-hydroxy-1,1,1,3,3,3-hexafluoro-2-propyl) cyclohexyl) -1,1,1,3,3,3-hexafluoropropyltrifluoromethyl acrylate, 5- Polymerizable compounds having a hydroxyfluoroalkyl group such as (2-hydroxy-1,1,1,3,3,3-hexafluoro-2-propyl) methyl-2-norbornene That.

Examples of the acid dissociable protecting group include a tert-butyl group, a tert-amyl group, a 1-methyl-1-cyclopentyl group, a 1-ethyl-1-cyclopentyl group, and a 1-methyl-1-cyclohexyl group. 1-ethyl-1-cyclohexyl group, 2-methyl-2-adamantyl group, 2-ethyl-2-adamantyl group, 2-propyl-2-adamantyl group, 2- (1-adamantyl) -2-propyl group, 8-methyl-8-tricyclo [5.2.1.0 ^2,6 ] decanyl group, 8-ethyl-8-tricyclo [5.2.1.0 ^2,6 ] decanyl group, 8-methyl-8- Tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecanyl group, 8-ethyl-8-tetracyclo [4.4.0.1 ^2,5 . 1 ^{7, 10} ] saturated hydrocarbon group such as dodecanyl group; 1-methoxyethyl group, 2-ethoxyethyl group, 1-iso-propoxyethyl group, 1-n-butoxyethyl group, 1-tert-butoxyethyl group, 1-cyclopentyloxyethyl group, 1-cyclohexyloxyethyl group, 1-tricyclo [5.2.1.0 ^2,6 ] decanyloxyethyl group, methoxymethyl group, ethoxymethyl group, iso-propoxymethyl group, n Oxygenated carbon such as -butoxymethyl group, tert-butoxymethyl group, cyclopentyloxymethyl group, cyclohexyloxymethyl group, tricyclo [5.2.1.0 ^2,6 ] decanyloxymethyl group, tert-butoxycarbonyl group A hydrogen group etc. are mentioned.

  After polymerizing a monomer having an alkali-soluble chemical structure and then protecting the alkali-soluble group in the alkali-soluble chemical structure with an acid-dissociable protecting group, the compound having the alkali-soluble group is directly polymerized. Then, an acid-dissociable protecting group can be introduced by reacting with a compound that gives a substituent that does not dissolve in an alkali such as vinyl ether or halogenated alkyl ether under an acid catalyst. Examples of the acid catalyst used in the reaction include p-toluenesulfonic acid, trifluoroacetic acid, and strongly acidic ion exchange resin.

  Examples of the monomer that gives the repeating unit (2) having a polar group for improving adhesion to the substrate include compounds having a phenolic hydroxyl group, a carboxyl group, or a hydroxyfluoroalkyl group as the polar group. Specifically, for example, as the polymerizable compound containing an alkali-soluble group, hydroxystyrenes described above, carboxylic acids having an ethylenic double bond, polymerizable compounds having a hydroxyfluoroalkyl group, and these In addition to the monomer further substituted with a polar group, a monomer having a polar group bonded to an alicyclic structure such as a norbornene ring or a tetracyclododecene ring can be used.

The polar group introduced into the repeating unit (2) as a substituent is particularly preferably one containing a lactone structure, such as γ-butyrolactone, γ-valerolactone, δ-valerolactone, 1,3-cyclohexanecarbolactone. , 2,6-norbornanecarbolactone, 4-oxatricyclo [5.2.1.0 ^2,6 ] decan-3-one, and a substituent containing a lactone structure such as mevalonic acid δ-lactone.
Examples of polar groups other than the lactone structure include hydroxyalkyl groups such as a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group, and a 3-hydroxy-1-adamantyl group.

Furthermore, as a monomer which gives the repeating unit (3) having a nonpolar substituent for adjusting the solubility in a resist solvent or an alkali developer, which is contained as necessary, styrene, α-methyl Aromatic compounds having an ethylenic double bond such as styrene, p-methylstyrene, and indene; acrylic acid, methacrylic acid, trifluoromethyl acrylic acid, norbornene carboxylic acid, 2-trifluoromethyl norbornene carboxylic acid, carboxytetracyclo [ 4.4.0.1 ^2,5 . 1 ^7,10 ] ester compound in which acid-stable nonpolar group is substituted for carboxylic acid having ethylenic double bond such as dodecyl methacrylate; alicyclic carbonization having ethylenic double bond such as norbornene and tetracyclododecene A hydrogen compound etc. are mentioned.
Examples of acid-stable nonpolar substituents that are ester-substituted for the carboxylic acid include methyl, ethyl, cyclopentyl, cyclohexyl, isobornyl, and tricyclo [5.2.1.0 ^2,6 ] decanyl. Group, 2-adamantyl group, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecyl group and the like.

These monomers may be used individually by 1 type in each of repeating unit (1), (2), and (3), and may be used in combination of 2 or more type.
The composition ratio of each repeating unit in the resin contained in the positive-type radiation-sensitive resin composition for resist formation can be selected within a range that does not impair the basic performance as a resist. That is, in general, the repeating unit (1) is preferably 10 to 70 mol%, more preferably 10 to 60 mol%. The composition ratio of the repeating unit (2) is preferably 30 to 90 mol%, more preferably 40 to 90 mol%, but for the monomer unit having the same polar group, 70 mol% The following is preferable. Furthermore, the composition ratio of the repeating unit (3) is preferably 50 mol% or less, more preferably 40 mol% or less.

  On the other hand, the resin contained in the resin composition for forming the upper layer film and the lower layer film (antireflection film, etc.) in the multilayer resist is the same as the chemistry of the resin contained in the positive type radiation sensitive resin composition for resist formation described above. A polymer having a chemical structure in which the repeating unit (1) which is decomposed with an acid and becomes alkali-soluble is removed from the structure. The composition ratio of each repeating unit in the resin is not particularly limited, and is appropriately adjusted depending on the intended use of the coating film. Generally, the composition ratio of the repeating unit (2) is selected from the range of 10 to 100 mol%, and the composition ratio of the repeating unit (3) is selected from the range of 0 to 90 mol%.

  Further, when the upper layer film or the lower layer film in the multilayer resist is used as an antireflection film, the resin needs to include a crosslinking point and a chemical structure that absorbs radiation irradiated in photolithography. The point includes reactive substituents that can be cross-linked by an ester bond, a urethane bond, or the like, such as a hydroxyl group, an amino group, a carboxyl group, or an epoxy group. Examples of the monomer containing a reactive substituent serving as a crosslinking point include hydroxystyrenes such as p-hydroxystyrene and m-hydroxystyrene, and the above-described polymerizable compounds such as the hydroxyl group, amino group, and carboxyl. A monomer substituted with a reactive substituent such as a group or an epoxy group can be appropriately used.

  The chemical structure that absorbs radiation varies depending on the wavelength of the radiation used. For example, for ArF excimer laser light, a chemical structure containing a benzene ring and its analogs is preferably used. Examples of the monomer having such a chemical structure include styrenes such as styrene, α-methylstyrene, p-methylstyrene, p-hydroxystyrene, m-hydroxystyrene, and derivatives thereof; substituted or unsubstituted phenyl (meta And aromatic-containing esters having an ethylenic double bond such as acrylate, substituted or unsubstituted naphthalene (meth) acrylate, substituted or unsubstituted anthracenemethyl (meth) acrylate, and the like. The monomer having a chemical structure that absorbs radiation may be introduced as either the repeating unit (2) or (3) depending on the presence or absence of a polar group, but the monomer having a chemical structure that absorbs radiation. Is preferably selected from the range of 10 to 100 mol%. In the present specification, “(meth) acrylate” means acrylate and methacrylate.

In addition, the method for producing a photoresist resin of the present invention has a low solubility in a polymerization solvent described later, and even when a solid monomer or the like that requires a large amount of a solvent for dissolving a monomer is used, the monomer polymer The conversion rate to can be improved.
Specific examples of the polymerizable compound that is solid at room temperature used in the present invention include, for example, 5-methacryloyloxy-2,6-norbornanecarbolactone, 2-ethyl-2-adamantyl methacrylate, 5-oxo-4- Oxa-tricyclo [5.2.1.0 ^3,8 ] dec-2-yl methacrylate, 3- (2-hydroxyethoxy) -1-adamantyl methacrylate, 2-isopropyl-2-adamantyl methacrylate, 2-[[( Trifluoromethyl) sulfonyl] amino] ethyl methacrylate, 1,2-cyclohexanedicarboxylic acid mono [2-[(2-methyl-1-oxo-2-propenyl) oxy] ethyl] ester, 5- [3,3,3 -Trifluoro-2-hydroxy-2- (trifluoromethyl) propyl] bi Chro [2.2.1] heptan-2-yl methacrylate, 6- [3,3,3-trifluoro-2-hydroxy-2- (trifluoromethyl) propyl] bicyclo [2.2.1] heptane- Examples include 2-yl methacrylate.

Moreover, the polymerization method of the said polymeric compound is not specifically limited, Well-known methods, such as solution polymerization, can be used.
The resin solution containing the photoresist resin is obtained, for example, by using a polymerization initiator and, if necessary, using a chain transfer agent, and polymerizing the polymerizable compound in an appropriate solvent. be able to.
Specifically, for example, (1) a method of polymerizing a solution containing a monomer (polymerizable compound) and a polymerization initiator in a reaction vessel containing a solvent, and (2) a reaction containing a solvent. A method in which a solution containing a monomer and a solution containing a polymerization initiator are dropped into a container and polymerized, and (3) a monomer, a polymerization initiator and a solvent are charged in a reaction vessel and polymerized in a batch system. Methods and the like.

  Examples of the polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), dimethyl 2,2′-azobisisobutyrate, 1,1′- Azo compounds such as azobis (cyclohexane-1-carbonitrile), 4,4′-azobis (4-cyanovaleric acid), decanoyl peroxide, lauroyl peroxide, benzoyl peroxide, bis (3,5,5-trimethyl) Hexanoyl) peroxide, succinic acid peroxide, radical polymerization initiators such as organic peroxides such as tert-butylperoxy-2-ethylhexanoate. These polymerization initiators may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of the chain transfer agent include thiol compounds such as dodecyl mercaptan, mercaptoethanol, mercaptopropanol, mercaptoacetic acid, mercaptopropionic acid, and 4,4-bis (trifluoromethyl) -4-hydroxy-1-mercaptobutane. be able to. These chain transfer agents may be used individually by 1 type, and may be used in combination of 2 or more type.

The amount of the polymerization initiator and chain transfer agent used is appropriately adjusted according to the production conditions such as the raw material monomer (polymerizable compound) used in the polymerization reaction, the polymerization initiator, the type of chain transfer agent, the polymerization temperature, the polymerization solvent, and the purification conditions. can do.
In general, if the weight average molecular weight of the resin is too high, the solubility in a solvent or an alkali developer used for forming a coating film tends to be low. On the other hand, when the weight average molecular weight is too low, the coating film performance tends to deteriorate. Therefore, the polystyrene-reduced weight average molecular weight (hereinafter also referred to as “Mw”) by gel permeation chromatography (GPC) is preferably adjusted to be in the range of 2000 to 40000, more preferably 3000 to 30000.

  Further, the solvent (polymerization solvent) used in the polymerization reaction is not particularly limited. For example, water, acetone, methyl ethyl ketone, methyl amyl ketone, cyclohexanone, methyl isobutyl ketone, tetrohydrofuran, dioxane, propylene glycol monomethyl ether, ethyl lactate, It is preferable to use at least one of propylene glycol monomethyl ether acetate, benzene and toluene. When these polymerization solvents are used, a photoresist resin with a high yield and fewer impurities can be obtained. Furthermore, the molecular weight distribution of the obtained photoresist resin can be narrowed, and physical properties such as optical properties, chemical properties, coating properties and adhesion to the substrate or lower layer film required for resist films and antireflection films. Can be improved.

  Although the usage-amount of the said polymerization solvent is not specifically limited, Usually, it is 0.5-20 mass parts with respect to 1 mass part of monomers, Preferably it is 1-10 mass parts. If the amount of the solvent used is too small, the monomer may precipitate or become too viscous to keep the polymerization system uniform. On the other hand, when the amount of the solvent used is too large, the conversion rate of the raw material monomer may be insufficient, or the molecular weight of the polymer (resin) obtained may not be increased to a desired value.

Moreover, in the manufacturing method of the resin for photoresists in this invention, a solvent is distilled off during a polymerization reaction. In this way, by distilling off the solvent, the solid content concentration (particularly the monomer concentration) in the polymerization solution can be maintained at a higher concentration than before, and the monomer used as the resin raw material is converted into a polymer. The conversion rate can be greatly improved.
The method for distilling off the solvent is not particularly limited as far as evaporation can be carried out. For example, a part of the reaction solvent refluxed to the polymerization vessel can be distilled off by using a Claisen type connecting tube or the like.

  The amount of the solvent distilled off during the polymerization reaction is not particularly limited and can be adjusted as appropriate. For example, the distillation amount is preferably 25 to 65% by mass, more preferably 28 to 45% by mass, further preferably 100% by mass when the total amount of the solvent used in the polymerization is 100% by mass. 30 to 40% by mass. When the amount of this distillation is 25 to 65% by mass, it can be concentrated while sufficiently dissolving the solids such as monomers, and the polymerization can be performed by increasing the solids concentration, so that the conversion rate to the polymer is improved. However, it is preferable because of high yield.

  Further, the distillation rate of the solvent during the polymerization reaction is not particularly limited, and can be appropriately adjusted. For example, the distillation rate is preferably 5 to 44% by mass, more preferably 5 to 30% by mass, when the initial total amount of the solvent used in the polymerization is 100% by mass. / H, more preferably 8 to 22% by mass / h, particularly preferably 10 to 17% by mass / h. A distillation rate of 5 to 44% by mass / h is preferable because precipitation of solids (monomer and the like) due to rapid concentration can be prevented. In the present invention, the degree of polymerization and the molecular weight distribution of the reaction-generated resin can be controlled within a predetermined range by adjusting the distillation rate in this way.

  The solvent may be distilled off continuously or intermittently during the polymerization reaction. Specifically, for example, when the polymerization time by dropping of the monomer solution or the like is X hours, (1) the solvent may be distilled off continuously for X hours so as to obtain a predetermined distillation amount ( (Continuous distillation), (2) the solvent may be distilled off for less than X hours (intermittent distillation), or (3) the predetermined amount The solvent may be distilled off several times within a range of not more than X hours in total (intermittent distillation).

The reaction conditions in the polymerization are not particularly limited, and can be appropriately adjusted according to the monomer used, the polymerization solvent, and the like. For example, the reaction temperature is usually 40 to 120 ° C, preferably 50 to 100 ° C. The reaction time is usually 1 to 48 hours, preferably 1 to 24 hours.
The pressure during the polymerization is not particularly limited, but from the viewpoint that a polymer can be obtained with good reproducibility, it is preferable to adjust the pressure and perform the reaction under a constant pressure, under normal pressure (atmospheric pressure) or under pressure. It is more preferable to carry out with. In particular, the condition under pressure is preferable because the pressure can be easily controlled with an inert gas such as nitrogen without using a device such as a vacuum pump.
The specific pressurizing condition [pressure (hPa)] exceeds, for example, normal pressure (101.25) and is preferably 1300 hPa or less, more preferably 1020 to 1100 hPa, still more preferably 1020 to 1080 hPa.

  It is preferable that the density | concentration (solid content density | concentration) of the resin solution obtained by this polymerization reaction is 1-80 mass%, More preferably, it is 5-50 mass%, More preferably, it is 10-50 mass%.

  In the method for producing a photoresist resin of the present invention, the resin solution containing the photoresist resin obtained by the above-described polymerization reaction is subjected to a known purification treatment and dried to obtain a resin. Minutes (solid content) can be separated.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

[1] Production of a resin solution containing a resin for photoresist (Examples 1 to 3, Comparative Examples 1 to 4)
Example 1
A 810 mL four-necked flask is equipped with a Dimroth tube, a Claisen type connecting tube equipped with a receiver, and a thermometer. After 40 g of methyl ethyl ketone is fully substituted with nitrogen, the mixture is heated to 80 ° C. while stirring with a three-one motor. The temperature rose.
Thereafter, 62 g of 5-methacryloyloxy-2,6-norbornanecarbolactone (NLM), 98 g of 2-methyl-2-adamantyl methacrylate (MAdMA), and 11.5 g of azobisisobutyronitrile were dissolved in 200 g of methyl ethyl ketone. It was dripped at a constant speed by a dropping funnel over 3 hours. This polymerization reaction was performed while refluxing a polymerization solvent (methyl ethyl ketone) through the Dimroth tube. Simultaneously with the start of dropping, 80 g of methyl ethyl ketone (33.3% by mass when the total amount of the solvent is 100% by mass) in the flask is distilled out for 3 hours through the Claisen type connecting tube under a pressure of 1040 hPa. I let you. The distillation rate was kept constant at 26.7 g per hour (11.1% by mass / h when the initial total amount of solvent was 100% by mass).
After completion of dropping, the mixture was further aged for 3 hours, and then cooled to room temperature to obtain a resin solution containing the photoresist resin of Example 1.
And as a result of measuring the conversion rate of the monomer to the polymer, it was 97.9 mass%. In addition, this conversion rate is converted into a weight ratio by applying a value (area fraction of 100) obtained by gel permeation chromatography (GPC) measurement to a calibration curve prepared in advance. Moreover, the detail of the calculation method of GPC measurement and a monomer conversion rate is shown below.

<GPC measurement method>
Dilute 0.05 g of the resin solution after polymerization with tetrahydrofuran to a total amount of 5.00 g. After filtering this with a 0.45 μm filter, it is packed in a special glass vial and measurement is started. The unreacted monomer component was judged from the elution time.
Apparatus: HLC8220 manufactured by Tosoh Corporation
Column: Combination of TSKguardcolumn SuperH-L, TSKgel SuperH4000, TSKgel SuperH2000 Column temperature: 40 ° C
Injection volume: 10μ?
Measurement flow rate: 0.6 m? / Min

<Method for calculating monomer conversion>
The resin from which the unreacted monomer component was sufficiently removed was dissolved in tetrahydrofuran to obtain a sample for a calibration curve. Several types of samples with varying amounts of resin dissolved in tetrahydrofuran were prepared and subjected to GPC measurement. A regression equation was obtained from the relationship between the amount of resin applied to the column and the area, and a calibration curve was prepared. The measurement conditions followed the GPC measurement method described above.

(Example 2)
A 810 mL four-necked flask is equipped with a Dimroth tube, a Claisen type connecting tube equipped with a receiver, and a thermometer. After 40 g of methyl ethyl ketone is fully substituted with nitrogen, the mixture is heated to 80 ° C. while stirring with a three-one motor. The temperature rose.
Thereafter, 62 g of 5-methacryloyloxy-2,6-norbornanecarbolactone (NLM), 98 g of 2-methyl-2-adamantyl methacrylate (MAdMA), and 11.5 g of azobisisobutyronitrile were dissolved in 200 g of methyl ethyl ketone. It was dripped at a constant speed by a dropping funnel over 3 hours. This polymerization reaction was performed while refluxing a polymerization solvent (methyl ethyl ketone) through the Dimroth tube. In addition, at the same time as the start of dropping, 80 g of methyl ethyl ketone [total amount of solvent [40 (g) +200 (g) = 240 (g)] in the flask over 100 hours was set to 33.3% by mass. ] Was distilled off through the Claisen type connecting tube under a pressure of 1040 hPa. The distillation rate was kept constant at 53.3 g per hour (22.2% by mass / h when the initial total amount of solvent was 100% by mass).
After completion of the dropwise addition, the mixture was further aged for 3 hours and then cooled to room temperature to obtain a resin solution containing the photoresist resin of Example 2.
And as a result of measuring the conversion rate of a monomer like Example 1, it was 97.4 mass%.

(Example 3)
A 810 mL four-necked flask is equipped with a Dimroth tube, a Claisen type connecting tube equipped with a receiver, and a thermometer. After 40 g of methyl ethyl ketone is fully substituted with nitrogen, the mixture is heated to 80 ° C. while stirring with a three-one motor. The temperature rose.
Thereafter, 62 g of 5-methacryloyloxy-2,6-norbornanecarbolactone (NLM), 98 g of 2-methyl-2-adamantyl methacrylate (MAdMA), and 11.5 g of azobisisobutyronitrile were dissolved in 200 g of methyl ethyl ketone. It was dripped at a constant speed by a dropping funnel over 3 hours. This polymerization reaction was performed while refluxing a polymerization solvent (methyl ethyl ketone) through the Dimroth tube. Further, from 1.5 hours after the start of dropping, when 80 g of methyl ethyl ketone [total amount of solvent [40 (g) +200 (g) = 240 (g)] in the flask was taken as 100% by mass over a period of 1.5 hours, 33 .3% by mass] was distilled off through the Claisen type connecting tube under a pressure of 1040 hPa. The distillation rate was kept constant at 53.3 g per hour (22.2% by mass / h when the initial total amount of solvent was 100% by mass).
After completion of the dropwise addition, the mixture was further aged for 3 hours and then cooled to room temperature to obtain a resin solution containing the photoresist resin of Example 3.
And as a result of measuring the conversion rate of a monomer like Example 1, it was 97.4 mass%.

(Comparative Example 1)
A 810 mL four-necked flask was equipped with a Dimroth tube and a thermometer. After 40 g of methyl ethyl ketone was added and sufficiently purged with nitrogen, the temperature was raised to 80 ° C. while stirring with a three-one motor.
Thereafter, 62 g of 5-methacryloyloxy-2,6-norbornanecarbolactone (NLM), 98 g of 2-methyl-2-adamantyl methacrylate (MAdMA) and 5.7 g of azobisisobutyronitrile were dissolved in 200 g of methyl ethyl ketone. It was dripped at a constant speed by a dropping funnel over 3 hours. This polymerization reaction was performed while refluxing a polymerization solvent (methyl ethyl ketone) through the Dimroth tube.
After completion of dropping, the mixture was further aged for 3 hours, and then cooled to room temperature to obtain a resin solution containing the photoresist resin of Comparative Example 1.
And as a result of measuring the conversion rate of a monomer like Example 1, it was 94.4 mass%.

(Comparative Example 2)
A 810 mL four-necked flask was equipped with a Dimroth tube and a thermometer. After 40 g of methyl ethyl ketone was added and sufficiently purged with nitrogen, the temperature was raised to 80 ° C. while stirring with a three-one motor.
Thereafter, 62 g of 5-methacryloyloxy-2,6-norbornanecarbolactone (NLM), 98 g of 2-methyl-2-adamantyl methacrylate (MAdMA), and 11.5 g of azobisisobutyronitrile were dissolved in 200 g of methyl ethyl ketone. It was dripped at a constant speed by a dropping funnel over 3 hours. This polymerization reaction was performed while refluxing a polymerization solvent (methyl ethyl ketone) through the Dimroth tube.
After completion of dropping, the mixture was further aged for 3 hours, and then cooled to room temperature to obtain a resin solution containing the photoresist resin of Comparative Example 2.
And as a result of measuring the conversion rate of a monomer like Example 1, it was 95.4 mass%.

(Comparative Example 3)
A 810 mL four-necked flask was equipped with a Dimroth tube and a thermometer. After 40 g of methyl ethyl ketone was added and sufficiently purged with nitrogen, the temperature was raised to 80 ° C. while stirring with a three-one motor.
Thereafter, 62 g of 5-methacryloyloxy-2,6-norbornanecarbolactone (NLM), 98 g of 2-methyl-2-adamantyl methacrylate (MAdMA), and 8.6 g of azobisisobutyronitrile were dissolved in 200 g of methyl ethyl ketone. It was dripped at a constant speed by a dropping funnel over 3 hours. This polymerization reaction was performed while refluxing a polymerization solvent (methyl ethyl ketone) through the Dimroth tube.
After completion of dropping, the mixture was further aged for 3 hours, and then cooled to room temperature to obtain a resin solution containing the photoresist resin of Comparative Example 3.
And as a result of measuring the conversion rate of a monomer like Example 1, it was 95.0 mass%.

(Comparative Example 4)
A 810 mL four-necked flask was equipped with a Dimroth tube and a thermometer. After 80 g of methyl ethyl ketone was added and sufficiently purged with nitrogen, the temperature was raised to 80 ° C. while stirring with a three-one motor.
Thereafter, a solution of 31 g of 5-methacryloyloxy-2,6-norbornanecarbolactone (NLM), 49 g of 2-methyl-2-adamantyl methacrylate (MAdMA) and 2.9 g of azobisisobutyronitrile in 160 g of methyl ethyl ketone was prepared. It was dripped at a constant speed by a dropping funnel over 3 hours. This polymerization reaction was performed while refluxing a polymerization solvent (methyl ethyl ketone) through the Dimroth tube.
After completion of dropping, the mixture was further aged for 3 hours, and then cooled to room temperature to obtain a resin solution containing the photoresist resin of Comparative Example 4.
And as a result of measuring the conversion rate of a monomer like Example 1, it was 84.7 mass%.

  Raw material composition (monomer, polymerization initiator and solvent), polymerization conditions, solvent evaporation rate, distillation in the preparation of resin solutions containing the photoresist resins of Examples 1 to 3 and Comparative Examples 1 to 4 Table 1 summarizes the last time, the amount of distillation, and the conversion ratio of the monomer to the polymer. In Table 1, “monomer A” represents “5-methacryloyloxy-2,6-norbornanecarbolactone”, “monomer B” represents “2-methyl-2-adamantyl methacrylate”, “ “Polymerization initiator” indicates “azobisisobutyronitrile”, and “solvent” indicates “total amount of methyl ethyl ketone used for polymerization”. In Table 1, “Solid Concentration (Initial)” in Examples 1 to 3 indicates the solid content concentration in the charging stage, and “Solid Concentration (After Polymerization)” indicates the solid content concentration after polymerization. Show.

[2] Effect of Examples According to Table 1, in Examples 1 to 3 in which the solvent was distilled off during the polymerization reaction, it was found that the conversion rate of the raw material monomer to the polymer was excellent.

Claims (6)

A method for producing a photoresist resin, which comprises producing a photoresist resin by polymerizing a polymerizable compound in the presence of a solvent,
The polymerizable compound is a monomer having an ethylenically unsaturated bond,
At least one of the polymerizable compounds is a solid compound at room temperature,
A method for producing a photoresist resin, wherein a solvent is distilled off during a polymerization reaction. The compound which is solid at room temperature includes 5-methacryloyloxy-2,6-norbornanecarbolactone, 2-ethyl-2-adamantyl methacrylate, 5-oxo-4-oxa-tricyclo [5.2.1.0 ^{3, 8} ] Dec-2-yl methacrylate, 3- (2-hydroxyethoxy) -1-adamantyl methacrylate, 2-isopropyl-2-adamantyl methacrylate, 2-[[(trifluoromethyl) sulfonyl] amino] ethyl methacrylate, 1, 2-cyclohexanedicarboxylic acid mono [2-[(2-methyl-1-oxo-2-propenyl) oxy] ethyl] ester, 5- [3,3,3-trifluoro-2-hydroxy-2- (trifluoro) Methyl) propyl] bicyclo [2.2.1] heptan-2-yl methacrylate Or 6- [3,3,3-trifluoro-2-hydroxy-2- (trifluoromethyl) propyl] bicyclo [2.2.1] heptan-2-yl methacrylate. A method for producing a resin for photoresist.   The resin for photoresists according to claim 1 or 2, wherein the amount of the solvent distilled off during the polymerization reaction is 25 to 65% by mass when the total amount of the solvent used in the polymerization is 100% by mass. Manufacturing method.   The method for producing a photoresist resin according to claim 1, wherein the reaction solvent is distilled off continuously or intermittently.   The evaporation rate of the solvent during the polymerization reaction is 5 to 44% by mass / h when the initial total amount of the solvent used in the polymerization is 100% by mass. The manufacturing method of resin for photoresists as described in any one of.   The method for producing a photoresist resin according to claim 1, wherein the polymerization reaction is performed under pressure.