JP2009080452A - Photosensitive resin composition - Google Patents

Abstract

Disclosed is a photosensitive resin composition that is not accompanied by decarboxylation when generating a base by irradiation with light, provides a cured film having high film strength, and is excellent in high-temperature resistance.
A photocyclization-type photobase generator represented by the general formula (1) that generates an amine compound without decarboxylation upon irradiation with light, and a base-reactive resin. According to the featured photosensitive resin composition, a cured film having excellent high temperature resistance and high film strength can be obtained.

[In General Formula (1), Z represents an amino group. ]
[Selection figure] None

Description

  The present invention relates to a photosensitive resin composition containing a photobase generator that generates a base upon irradiation with active energy rays.

  Photosensitive resin compositions that undergo chemical structural changes upon irradiation with active energy rays such as light, infrared rays, far-infrared rays, electron beams, or X-rays are widely used as resist materials and photo-curing materials. Yes. Of the active energy rays, light is particularly widely used. Hereinafter, although an active energy ray is demonstrated only as light, the active energy ray in this invention is not limited to light.

  For example, a chemically amplified resist material containing a photoacid generator that generates a strong acid upon irradiation with active energy rays is known. In this chemically amplified resist material, pattern formation is performed by chemically modifying a resin component using a strong acid generated by irradiation of active energy rays as a catalyst to change the solubility in a developing solution. Although various resist materials have been developed with the aim of high sensitivity and high resolution, the types of combinations of photoacid generators and resins have been limited, and the development of new photosensitive systems is required. ing.

  Further, surface coating materials using photocuring of monomers and prepolymers by irradiation with active energy rays are known. In developing such surface coating materials, various attempts have been made to improve the photocuring rate of monomers, oligomers, and polymers. The most widely developed object is a radical polymerization material that polymerizes a large number of vinyl monomers using radical species generated by the action of light as initiators. In addition, active research has been conducted on cationic polymerization materials that generate an acid by the action of light and use this acid as a catalyst.

  However, in the case of a radical polymerization system, the polymerization reaction is limited by oxygen in the air. For this reason, a special device for blocking oxygen is required. In the case of a cationic polymerization system, although it is advantageous in that there is no such inhibition by oxygen, the strong acid generated from the photoacid generator remains after curing, indicating that it may corrode or modify the resin. Has been. For this reason, development of the photosensitive resin composition which does not contain corrosive substances, such as a strong acid, and does not receive the inhibition by the oxygen in the air but progresses rapidly with high efficiency has been strongly desired.

Therefore, a photosensitive resin composition has been proposed in which a base generated by the action of light is used for a polymerization reaction or a chemical reaction. For example, Patent Document 1 discloses a photosensitive resin composition containing a photobase generator that generates a base by the action of light, a polyimide precursor, and a solvent. According to this photosensitive resin composition, first, a basic amine compound is generated by irradiating light, and then by heat treatment, the generated amine compound and the polyimide precursor react to form a cured film. can get.
JP 2006-189591 A

  However, in the conventional photobase generator as used in Patent Document 1, when a base is generated by light irradiation, a carbon dioxide gas is generated at the same time because it involves a decarboxylation reaction. When the generated carbon dioxide gas remains in the cured film as bubbles, the strength of the cured film is reduced. In particular, when the thickness of the cured film is thick, there is a high possibility that carbon dioxide gas remains in the cured film.

  Furthermore, the conventional photobase generator as used in Patent Document 1 has an ester bond, and thus has a high resistance to high temperatures, and a base is generated even when no light is irradiated under high temperature conditions. . For this reason, in particular, when a photosensitive resin composition containing a polyimide precursor that requires a reaction at a high temperature is used as a resist material, a base is generated by heating even in an unexposed portion, It is difficult to form.

  The present invention has been made in view of the problems as described above, and the object thereof is to obtain a cured film having high film strength without accompanying a decarboxylation reaction when generating a base by irradiation with light. It is in providing the photosensitive resin composition excellent in high temperature tolerance.

  This inventor repeated earnest research in order to solve the said subject. As a result, a cured film with high film strength can be obtained by using a photocyclization type photobase generator that generates an amine compound by light irradiation without decarboxylation reaction. The present inventors have found that a functional resin composition can be obtained and have completed the present invention. More specifically, the present invention provides the following.

(1) A photosensitive resin composition comprising a base-reactive resin and a photobase generator represented by the following general formula (1).
[In General Formula (1), Z represents an amino group. ]

(2) In the said General formula (1), Z is group represented by the following general formula (z1), The photosensitive resin composition of (1) description characterized by the above-mentioned.
[In General Formula (z1), R ₁ and R ₂ may be the same or different and each represents hydrogen or an organic group having 1 to 18 carbon atoms which may have a substituent. The organic group is selected from the group consisting of an alkyl group, a cycloalkyl group, an aryl group, and an arylalkyl group. ]

(3) In the said General formula (1), Z is group represented by the following general formula (z2), The photosensitive resin composition of (1) description characterized by the above-mentioned.
[In General Formula (z2), n and m are each independently an integer of 1 to 6, and R ₃ represents hydrogen, a hydrocarbon group, a hydrocarbon oxy group, or an acyl group. ]

  (4) The photosensitive resin according to any one of (1) to (3), wherein the base-reactive resin is at least one selected from the group consisting of an epoxy resin, a silicon-containing resin, and a polyamic acid resin. Composition.

  (5) The photosensitive resin composition according to any one of (1) to (4) is applied on a support, dried, and subjected to a predetermined pattern exposure, followed by heat treatment and development to obtain a predetermined shape. A pattern forming method comprising obtaining a cured resin pattern.

  ADVANTAGE OF THE INVENTION According to this invention, when generating a base by irradiation of light, a decarboxylation reaction is not accompanied, a cured film with high film | membrane intensity | strength is obtained, and the photosensitive resin composition excellent in high temperature tolerance can be provided.

  Hereinafter, embodiments of the present invention will be described in detail.

[Photobase generator]
The photobase generator used in the photosensitive resin composition of the present invention is characterized in that it generates a basic amine compound by light irradiation without decarboxylation. Specifically, the photobase generator used in the photosensitive resin composition of the present invention is represented by the following general formula (1).

  In the general formula (1), Z represents an amino group. The amino group includes an unsubstituted amino group and a substituted amino group. The substituted amino group includes a mono-substituted amino group and a di-substituted amino group.

In the general formula (1), a photobase generator in which Z is a group represented by the following general formula (z1) is preferably used.

In the general formula (z1), R ₁ and R ₂ may be the same or different, and represent hydrogen or an organic group having 1 to 18 carbon atoms that may have a substituent. Preferably carbon number of an organic group is 6-12. The organic group is selected from the group consisting of an alkyl group, a cycloalkyl group, an aryl group, and an arylalkyl group.

  As the alkyl group, those having 1 to 12, particularly 2 to 6 carbon atoms are preferably used, and examples thereof include ethyl, propyl, butyl, hexyl and the like. As the cycloalkyl group, those having 5 to 10 carbon atoms, particularly 6 to 8 carbon atoms are preferably used, and examples thereof include cyclohexyl, cyclooctyl and the like. As the aryl group, those having 6 to 14 carbon atoms, particularly 6 to 10 carbon atoms are preferably used, and examples thereof include phenyl, tolyl, naphthyl and the like. As the arylalkyl group, those having 7 to 15 carbon atoms, particularly 7 to 11 carbon atoms are preferably used, and examples thereof include benzyl, phenethyl, naphthylmethyl and the like. These organic groups may have a substituent such as an amino group, an alkoxy group, an alkoxycarbonyl group, an acyl group, an acyloxy group, or a hydroxy group.

In the general formula (z1), R ₁ and R ₂ may be linked to each other to form a nitrogen-containing ring. In this case, the number of atoms constituting the nitrogen-containing ring is 3 to 12, preferably 5 to 8. In addition, a plurality of heteroatoms (N, O, S, etc.) may be contained in the atoms constituting this nitrogen-containing ring.

In the general formula (1), a photobase generator in which Z is a group represented by the following general formula (z2) is preferably used.

In the general formula (z2), n and m are each independently an integer of 1 to 6, preferably an integer of 2 to 4. n + m is preferably 4 to 12, and more preferably 4 to 8. R ₃ represents hydrogen, a hydrocarbon group, a hydrocarbon oxy group, or an acyl group, and may be a residue in which an amino group is eliminated from the photobase generator represented by the general formula (1). The hydrocarbon group, the hydrocarbon group in the hydrocarbon oxy group, and the hydrocarbon group in the acyl group preferably have 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms. This hydrocarbon group includes alkyl, cycloalkyl, aryl, arylalkyl.

In the photobase generator used in the present invention, a photocyclization reaction proceeds as shown by the following chemical reaction formula (1) by light irradiation. In this photocyclization reaction, a primary or secondary amine compound is generated without decarboxylation. For this reason, unlike the conventional photobase generator with a decarboxylation reaction as shown by the following chemical reaction formula (2), it is possible to suppress a decrease in strength of the cured film due to the generation of carbon dioxide gas.

  Moreover, since the photobase generator used in the present invention does not have an ester bond in its skeleton, it has excellent high temperature resistance as compared with conventional photobase generators. Therefore, even when a photosensitive resin composition containing this photobase generator and a polyimide precursor (polyamic acid) that reacts at a high temperature is used as a resist material, in the unexposed portion by heating. A good pattern can be formed without generating a base.

Specifically, the following are preferably exemplified as the photobase generator used in the present invention.

[Base-reactive resin]
The base-reactive resin used in the present invention is not particularly limited as long as it reacts with the amine compound generated from the photobase generator. A base-reactive resin used for a conventionally known resist composition or photo-curing resin is used. Hereinafter, examples of the base-reactive resin used in the photosensitive resin composition of the present invention are shown in chemical formulas (a1) to (a10).

  Of the base-reactive resins represented by the chemical formulas (a1) to (a6), the base-reactive resins represented by the chemical formulas (a1) to (a4) cause elimination and decarboxylation by the action of the base. . In addition, the base-reactive resins represented by the chemical formulas (a5) to (a6) cause elimination reaction by the action of the base.

  Among the basic reactive resins represented by the chemical formulas (a7) to (a10), the basic reactive resins (mixtures) represented by the chemical formulas (a7) and (a8) are subjected to dehydration condensation and crosslinking reaction by the action of the base. Produce. The base-reactive resin (polymer) represented by the chemical formula (a9) generates a decarboxylation reaction by the action of a base. The base-reactive resin represented by the chemical formula (a10) causes a polyimide forming reaction by the action of a base.

In the photosensitive resin composition of the present invention, the base reactive resin is preferably at least one selected from the group consisting of epoxy resins, silicon-containing resins, and polyamic acid resins. The polyamic acid resin is as described above. For example, ring opening polymerization of an epoxy group can be caused by allowing a base (amine) generated by light irradiation to act on a resin having at least two epoxy groups. Moreover, the epoxy resin can be chemically modified by adding an amine generated by light irradiation to the epoxy resin. Specific examples of the base-reactive resin having an epoxy group are shown in chemical formulas (a11) to (a22).

Further, as the silicon-containing resin, for example, a resin having a silanol group or an alkoxysilyl group is used. By causing a base (amine) generated by light irradiation to act on a resin having at least two silanol groups or alkoxysilyl groups, polycondensation of the silanol groups or alkoxysilyl groups can be caused. Specific examples of the base reactive resin having a silanol group or an alkoxysilyl group are shown in chemical formulas (a23) to (a26).

  In the photosensitive resin composition of this invention, it is preferable that content of the said photobase generator is 1 mass%-60 mass% with respect to the said base reactive resin, More preferably, it is 2 mass%-30%. % By mass. When the content of the photobase generator is less than 1% by mass, the reaction becomes insufficient. When the content exceeds 60% by mass, the photobase generator itself has a great influence on the solubility of the base-reactive resin, and the price. Disadvantageous.

  The base reactive resin used in the present invention is preferably a resin that initiates a polymerization reaction by light. Therefore, the photosensitive resin composition of the present invention is preferably a composition comprising a polymerizable epoxy resin, a polymerizable silicon-containing compound (resin), or a polyamic acid resin, and the photobase generator. Moreover, auxiliary components, such as a solvent, a hardening accelerator, and another filler, can be mix | blended as needed. In order to expand the photosensitive wavelength region of the photobase generator, a photosensitizer can be appropriately present together.

[Pattern formation method]
The pattern forming method of the present invention is characterized by using a photosensitive resin composition containing the above-described photobase generator and a base-reactive resin. For example, the photosensitive resin composition is dissolved in an organic solvent to prepare a coating solution, and the coating solution is applied onto a support such as a substrate and dried to form a coating film. Subsequently, pattern exposure is performed with respect to this coating film, and a base is generated. Subsequently, heat treatment is performed to advance the reaction of the base-reactive resin. After completion of the reaction, a cured resin pattern having a predetermined shape is obtained by performing development by immersing in a solvent (developer) in which a difference in solubility occurs between the exposed portion and the unexposed portion.

  In addition, the conditions of heat processing are suitably set according to the exposure energy, the kind of used photobase generator, and the kind of base reactive resin. The heating temperature is preferably 50 ° C to 250 ° C, more preferably 60 ° C to 130 ° C. The heating time is preferably 10 seconds to 60 minutes, more preferably 60 seconds to 30 minutes.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

<Synthesis Example 1>
o-Hydroxy-trans-cinnamic acid 1.8 g, cyclohexylamine 0.99 g, condensing agent 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride (hereinafter referred to as EDC) 2.1 g, THF solvent It was dissolved in and allowed to react at room temperature for 15 hours. After completion of the reaction, the reaction mixture was diluted with chloroform, and the organic layer was washed with diluted hydrochloric acid, water, and saturated aqueous sodium hydrogen carbonate solution in that order. After drying over anhydrous magnesium sulfate, the solvent was removed, and recrystallization with chloroform gave white crystals. It was. The yield was 46%, and the melting point (decomposition point) of the obtained white crystals was very high at 240 to 241 ° C. as a result of DSC measurement. It was. The obtained white crystals were identified by ¹ H-NMR, IR, UV, and elemental analysis.

¹ H-NMR (300 MHz, acetone-d ₆ ) δ (ppm) = 8.96 (s, 1H, OH), 7.85 (d, 1H, J = 16 Hz, C H = CHCO), 7.46 ( dd, 1H, J = 7.7 Hz, 1.5 Hz, -NH-), 7.20 to 6.82 (m, 4H, Ar-H), 6.71 (d, 1H, J = 16 Hz, CH = C H CO), 3.80 (m , 1H, -N-CH -), 2.09~1.71 (m, 10H, Ar-H).
IR (KBr, cm ⁻¹ ): 3300 (ν _O—H ), 3100, 2900, 2850 (ν _C—H ), 1650 (ν _CO—NH ), 1550 (ν _C—H ).
λ _max (nm): 270 (methanol).
Calculated value for C ₁₅ H ₁₉ NO ₂ = C: 73.4%, H: 7.81%, N: 5.71%, Analytical value = C: 73.5%, H: 8.00%, N : 5.70%.

From the above analysis results, it was confirmed that the white crystal obtained in Synthesis Example 1 was a photobase generator I represented by the following chemical formula (I).

<Synthesis Example 2>
3.6 g of o-hydroxy-trans-cinnamic acid, 2.0 g of 1,3-di-4-piperidylpropane, and 2.1 g of EDC as a condensing agent were dissolved in a THF / dichloromethane mixed solvent and reacted at room temperature for 15 hours. I let you. After completion of the reaction, the reaction mixture was diluted with chloroform, and the organic layer was washed with diluted hydrochloric acid, water, and saturated aqueous sodium hydrogen carbonate solution in that order. After drying over anhydrous magnesium sulfate, the solvent was removed, and recrystallization with chloroform gave white crystals. It was. The yield was 11%. The melting point (decomposition point) of the obtained white crystals was very high at 241 ° C. as a result of DSC measurement, and thus was considered to have excellent high temperature resistance. The white crystals obtained were identified by ¹ H-NMR and IR.

¹ H-NMR (300 MHz, DMSO-d ₆ ) δ (ppm) = 10.0 (s, 2H, OH), 7.4 (d, 2H, J = 15 Hz, C H = CHCO), 7.2 ( d, 2H, J = 15 Hz, CH = C H CO), 7.7 to 6.8 (m, 8H, Ar—H), 4.5 (d, 2H, Ar—H), 4.2 (d , 2H, Ar-H), 3.0 (m, 2H), 1.7 to 1.0 (m, 18H, Ar-H).
¹³ C-NMR (75 MHz, DMSO-d ₆ ) δ (ppm) = 27.86, 30.40, 39.34, 40.40 (CH ₂ ), 116.97 (CH), 120.69, 121. 76, 123.16, 129.73, 131.79, 137.44 (ArH), 157.84 (CH), 169.25 (C = O).
IR (KBr, cm < ^-1 >): 3400 ((nu) _O-H ), 2900,2850 ((nu) _C-H ), 1630 ((nu) _CO-NH ), 1560 ((nu) _C-H ).
Calculated as C ₃₁ H ₃₈ N ₂ O ₄ = C: 74.07%, H: 7.62%, N: 5.57%, Analytical = C: 74.13%, H: 7.58% , N: 5.30%.

From the above analysis results, it was confirmed that the white crystal obtained in Synthesis Example 2 was a photobase generator II represented by the following chemical formula (II).

<Synthesis Example 3>
2.1 g of o-hydroxy-trans-cinnamic acid, 1.2 g of hexamethylenediamine and 4.3 g of condensing agent EDC were dissolved in DMF as a solvent and reacted at room temperature for 24 hours. After completion of the reaction, the reaction mixture was diluted with chloroform, and the organic layer was washed with diluted hydrochloric acid, water, and saturated aqueous sodium hydrogen carbonate solution in that order. After drying over anhydrous magnesium sulfate, the solvent was removed, and recrystallization with chloroform gave white crystals. It was. The yield was 16%, and the melting point (decomposition point) of the obtained white crystal was very high at 220 ° C. as a result of DSC measurement. Therefore, it was considered that the white crystal was excellent in high temperature resistance. The obtained white crystals were identified by ¹ H-NMR, ¹³ C-NMR, IR, and elemental analysis.

¹ H-NMR (300 MHz, DMSO-d ₆ ) δ (ppm) = 1.18 to 1.45 (m, 8H, C H ₂ ), 3.16 (d, 4H, J = 5.8 Hz, NH— C H ₂ ), 6.68 (d, 1 H, J = 16 Hz, C H = CHCO), 6.78-7.59 (m, 10 H , ArH), 7.87 (d, 1 H, J = 16 Hz, CH = C H CO), 8.12 (t, 2H, J = 5.8Hz, N H), 10.12 (s, 2H, OH).
¹³ C-NMR (75 MHz, DMSO-d ₆ ) δ (ppm) = 27.86, 30.40, 39.34, 40.40 (CH ₂ ), 116.97 (CH), 120.69, 121. 76, 123.16, 129.73, 131.79, 137.44 (ArH), 157.84 (CH), 169.25 (C = O).
^{IR (KBr, cm -1):} 3330 (ν N-H), 3080 (ν O-H), 2940 (ν C-H), 2880 (ν C-H), 1650 (ν C = O), 860 (Ν _C-N ).
Calculated for _{C 24 H 28 N 2 O 4} = C: 70.58%, H: 6.91%, N: 6.86%, analysis = C: 69.87%, H: 6.75% , N: 7.04%.

From the above analysis results, it was confirmed that the white crystal obtained in Synthesis Example 3 was a photobase generator III represented by the following chemical formula (III).

<Synthesis Example 4>
o-Hydroxy-trans-cinnamic acid 2.1 g, 1,3-bis (3-aminopropyl) tetramethyldisiloxane 1.7 mL, condensing agent EDC 4.3 g were dissolved in solvent DMF and dissolved at room temperature. Reacted for hours. After completion of the reaction, the reaction mixture was diluted with chloroform, and the organic layer was washed with diluted hydrochloric acid, water, and saturated aqueous sodium hydrogen carbonate solution in that order. After drying over anhydrous magnesium sulfate, the solvent was removed, and recrystallization with chloroform gave white crystals. It was. The yield was 31%, and the melting point (decomposition point) of the obtained white crystals was a very high temperature of 226 ° C. as a result of DSC measurement, which was considered to be excellent in high temperature resistance. The obtained white crystals were identified by ¹ H-NMR, ²⁹ Si-NMR, IR, and elemental analysis.

¹ H-NMR (300 MHz, DMSO-d ₆ ) δ (ppm) = 0.0 (s, 12 H , —C H ₃ ), 0.44 to 0.47 (t, 4 H, J = 6.6 Hz, Si _{-C H 2 -), 1.37~1.44 (} dt, 4H, J = 6.6Hz, J = 8.2Hz, CH 2 -C H 2 -CH 2), 3.07~3.32 ( q, 1H, J = 16 Hz, CH = C H CO), 8.04 (t, 2H, J = 5.8 Hz, -N H- ), 9.94 (s, 2H, O H ).
²⁹ Si-NMR (99 MHz, DMSO-d ₆ ) δ (ppm) = − 8.44.
IR (KBr, cm ⁻¹ ): 3330 (ν _N—H ), 3080 (ν _O—H ), 2950 (ν _C—H ), 2870 (ν _C—H ), 1650 (ν _C═O ), 1400 _{(ν Si-CH3), 1100} (ν Si-O-Si), 880 (ν C-N).
C ₂₄ H ₂₈ N ₂ Calculated as _{O 4 = C: 61.89%,} H: 7.64%, N: 5.25%, analysis = C: 62.19%, H: 7.46% , N: 5.18%.

From the above analysis results, it was confirmed that the white crystal obtained in Synthesis Example 4 was a photobase generator IV represented by the following chemical formula (IV).

<Test Example 1>
The photobase generator obtained in Synthesis Example 1 was examined for photodegradation behavior in solution. Specifically, first, a solution was prepared by dissolving the photobase generator obtained in Synthesis Example 1 in methanol so as to have a concentration of 3.7 × 10 ⁻⁵ mol / l. Next, the prepared solution was irradiated with light of 254 nm, and then the UV spectrum of the solution was measured. FIG. 1 shows the change in the UV spectrum when the amount of light irradiation is changed stepwise.

  As shown in FIG. 1, it was found that the absorption near 270 nm and the absorption near 320 nm decreased while the absorption near 210 nm increased as the light irradiation amount increased. The absorption near 270 nm and the absorption near 320 nm are both derived from the photobase generator obtained in Synthesis Example 1, and the absorption near 210 nm is derived from the coumarin derived from the photocyclization reaction of the photobase generator. Absorption. From this, it was confirmed that by photoirradiation, the photocyclization reaction of the photobase generator obtained in Synthesis Example 1 occurred to generate cyclohexylamine.

<Test Example 2>
The photobase generator obtained in Synthesis Example 1 was examined for photodegradation behavior in solids. Specifically, a THF solution containing 20% by mass of the photobase generator obtained in Synthesis Example 1 with respect to polyglycidyl methacrylate (PGMA) was prepared and cast on a Si wafer. This was prebaked for 1 minute on a hot plate at 100 ° C. to obtain a film having a thickness of 0.8 μm. The obtained film was irradiated with light of 254 nm, and then the UV spectrum of the film was measured. FIG. 2 shows the change of the UV spectrum when the light irradiation amount is changed stepwise.

  As shown in FIG. 2, the photodecomposition behavior of the photobase generator obtained in Synthesis Example 1 in the solid was almost the same as the photodecomposition behavior in the solution. From this result, it was confirmed that the photobase generator obtained in Synthesis Example 1 effectively functions as a photobase generator in a photosensitive resin composition containing a base-reactive resin such as an epoxy resin.

<Test Example 3>
Each photobase generator obtained in Synthesis Examples 1, 3, and 4 was examined for solubility in various solvents. Specifically, it can be easily dissolved in less than 1 ml of solvent with respect to 0.01 g of the photobase generator ++, slightly soluble in 1-5 ml of solvent, and slightly dissolved in 5-10 ml of solvent. The thing which cannot be melt | dissolved even if the amount of solvent exceeds 10 ml was evaluated as-. The results are shown in Table 1. As shown in Table 1, among the photobase generators obtained in Synthesis Examples 1, 3, and 4, the photobase generator IV obtained in Synthesis Example 4 is particularly excellent in solubility. It was found that it can be applied to various applications.

<Example 1>
A THF solution containing 20% by mass of the photobase generator obtained in Synthesis Example 1 was prepared with respect to PGMA, and spin cast on a Si wafer at 3000 rpm for 30 seconds. This was prebaked for 1 minute on a 100 ° C. hot plate to obtain an uncured film having a thickness of 0.8 μm to 1.0 μm. A mask was placed on a part of the obtained uncured film, and light at 254 nm was irradiated from the top of the mask at 60 J / cm ² . After the irradiation, the mask was removed and heat treatment was performed at 140 ° C. for a predetermined time. The heating time was set at three levels of 2.5 minutes, 5 minutes, and 7.5 minutes. The IR spectrum (800-1100 cm < ^-1 >) of the exposure part at this time was shown in FIG. Moreover, the relationship between the peak area ratio derived from an epoxy group in the vicinity of 900 cm ⁻¹ and the heating time is shown in FIG.

  As apparent from FIGS. 3 and 4, it was found that the epoxy groups in the exposed portion were reduced by the heat treatment. From this result, the photobase generator obtained in Synthesis Example 1 functions effectively as a photobase generator in a photosensitive resin composition containing a base-reactive resin such as an epoxy resin. It was confirmed that the cross-linking reaction with the group proceeded and the desired cured film was obtained. That is, it was confirmed that the photosensitive resin composition containing the photobase generator obtained in Synthesis Example 1 and the base-reactive resin functions effectively as a negative resist.

<Example 2>
The same operation as in Example 1 was performed to obtain an uncured film similar to that in Example 1. A mask was placed on a portion of the obtained uncured film, and a predetermined amount of light at 254 nm was irradiated from above the mask. Next, the film thickness obtained by developing with THF for 30 seconds was measured, and the sensitivity was evaluated. Sensitivity evaluation was performed from the viewpoint of heating temperature dependency and heating time dependency. Regarding the heating temperature dependency, the heating time was fixed at 10 minutes and the heating temperature was set at three levels of 100 ° C., 120 ° C. and 140 ° C. Regarding the heating time dependency, the heating temperature was fixed at 120 ° C., and the measurement was performed at three levels of 5 minutes, 10 minutes, and 15 minutes. The results are shown in FIGS.

Sensitivity evaluation is the irradiation of light necessary for the residual film ratio (representing the film thickness after exposure and development / film thickness of the uncured film, which is synonymous with the normalized film thickness in this specification) to be 0.5 or more. This was done by comparing the amounts. As shown in FIG. 5, when the heating time is fixed at 10 minutes and the heating temperature is 100 ° C., the irradiation amount is 610 mJ / cm ² , whereas it is necessary when the heating temperature is 120 ° C. The amount of irradiation was 270 mJ / cm ² , and at 140 ° C., it was greatly reduced to 220 mJ / cm ² . From this result, it was found that the heating temperature is preferably 120 ° C. or higher when the heating time is 10 minutes.

Further, as shown in FIG. 6, when the heating temperature was fixed at 120 ° C. and the heating time was 5 minutes, an irradiation amount of 10,000 mJ / cm ² was required, whereas the heating time was 10 minutes. When it was done, it was as described above, and when it was 15 minutes, it was greatly reduced to 80 mJ / cm ² . From this result, it was found that when the heating temperature was 120 ° C., the heating time was preferably 10 minutes or more.

<Example 3>
The photobase generator obtained in Synthesis Example 2 was used instead of the photobase generator obtained in Synthesis Example 1, and 1,1,1,3,3,3-hexafluoro-2- An uncured film was obtained in the same manner as in Example 2 except that propanol (hereinafter referred to as HFIP) was used. The obtained uncured film was partially exposed to light through a mask and developed in the same manner as in Example 2 to evaluate the sensitivity. The results are shown in FIGS.

As shown in FIG. 7, when the heating time was fixed at 10 minutes and the heating temperature was 120 ° C., a residual film ratio of 0.5 was obtained with an irradiation amount of only 6.8 mJ / cm ² . When the heating temperature is 100 ° C., the remaining film rate of 0.5 or more cannot be obtained no matter how much the irradiation amount is increased. When the heating temperature is 140 ° C., the remaining film rate is 0 even with a very small irradiation amount. It was found that 5 or more were obtained. From this result, it was found that the heating temperature is preferably 120 ° C. or higher when the heating time is 10 minutes.

Further, as shown in FIG. 8, when the heating temperature is fixed at 120 ° C. and the heating time is 5 minutes, a residual film ratio of 0.5 is obtained with an irradiation amount of 20 mJ / cm ² and the heating time is 10 minutes. Was as described above. It was found that when the heating time was 15 minutes, a residual film ratio of 0.5 or more was obtained even with a very small dose. From this result, it was found that when the heating temperature was 120 ° C., the heating time was preferably 5 minutes or more.

  From the results of Example 3, it was confirmed that the photobase generator obtained in Synthesis Example 2 also functions effectively as a photobase generator, similarly to the photobase generator obtained in Synthesis Example 1. . Further, when the results of Example 2 and Example 3 are compared, the photobase generator obtained in Synthesis Example 2 is much more sensitive than the photobase generator obtained in Synthesis Example 1. I understand.

<Example 4>
Prepare HFIP solutions each containing 6.3 mol% of each photobase generator I-IV obtained in Synthesis Examples 1-4 for PGMA (Mw = 28000, Mw / Mn = 3.4) monomer units. Then, spin casting was performed on a Si wafer at 3000 rpm for 30 seconds. These were prebaked on a hot plate at 100 ° C. for 1 minute to obtain an uncured film having a thickness of 0.7 μm. A mask was placed on a part of the obtained uncured film, and light of 254 nm or 365 nm was irradiated from above the mask. Next, the mask was removed, heat treatment was performed at 100 ° C. for 15 minutes, and then development treatment with THF was performed for 30 seconds.

  Further, an uncured film was produced on a quartz glass plate using the solution prepared above. About the produced uncured film | membrane, the transmittance | permeability measurement of 254 nm light and 365 nm light was implemented using the ultraviolet visible spectrophotometer (Shimadzu "MultiSpec-1500").

  FIG. 9 and FIG. 10 show the relationship between the exposure energy at the exposure wavelengths of 254 nm and 365 nm, respectively, and the remaining film ratio of the exposed portion. The exposure amount at which the residual film ratio was 0.3 was defined as sensitivity, and the sensitivity evaluation results of each photobase generator are shown in Table 2.

  As a result of the transmittance measurement, the transmittance of 254 nm light was 30%, and the transmittance of 365 nm light was 80%. As shown in FIGS. 9 and 10 and Table 2, the bifunctional photobase generators II, III, and IV are more sensitive than the monofunctional photobase generator I. I understood. In addition, it was found that with the bifunctional photobase generators II, III, and IV, a higher residual film ratio can be obtained by increasing the exposure energy at an exposure wavelength of 365 nm.

Here, FIG. 11 shows IR spectra when an uncured film containing the photobase generator IV was irradiated with 1000 mJ / cm ^{2 of} 365 nm light and after heating at 100 ° C. for 15 minutes. The relationship between the peak area ratio derived from the epoxy group in the vicinity of 900 cm ⁻¹ and the heating time seen in FIG. 11 is shown in FIG.

As shown in FIGS. 11 and 12, it can be seen that the peak area derived from the epoxy group decreases as the heating proceeds, and the chemical reaction shown in the following chemical reaction formula (3) proceeds. It was thought that there was.

<Example 5>
6.3 mol% of the photobase generator IV obtained in Synthesis Example 4 and 1,3-bis of the base proliferating agent (BA) with respect to the PGMA (Mw = 28000, Mw / Mn = 3.4) monomer unit. An HFIP solution containing a predetermined amount of [1- (9-fluorenylmethoxycarbonyl) -4-piperidyl] propane was prepared and spin-cast on a Si wafer at 3000 rpm for 30 seconds. This was prebaked for 1 minute on a hot plate at 100 ° C. to obtain an uncured film having a thickness of 0.6 μm. A mask was placed on a portion of the resulting uncured film, and 365 nm light was irradiated from above the mask. Next, the mask was removed, heat treatment was performed at 100 ° C. for a predetermined time, and then development treatment with THF was performed for 30 seconds.

FIG. 13 shows the relationship between the exposure energy and the remaining film ratio when the blending amount of the base proliferating agent is changed to 0 mass%, 10 mass%, and 20 mass%. FIG. 14 shows the relationship between the exposure energy and the remaining film ratio when the blending amount of the base proliferating agent is 20 mass% and the heating time is changed to 10 minutes, 15 minutes, and 20 minutes. Here, in this example incorporating the base growth reaction, it was considered that the chemical reaction represented by the following chemical reaction formula (4) progressed. Further, from FIG. 13, a high residual film rate can be obtained by adding 20% by mass of the base proliferating agent, and from FIG. 14, a higher residual film rate as the heating time is increased by 10 minutes, 15 minutes, and 20 minutes. Was found to be obtained. From these results, it was considered that higher sensitivity could be achieved by adding a base proliferating agent.

<Example 6>
0.1 g of polymethacryloxypropyltrimethoxysilane (hereinafter referred to as PMAS) and 30% by mass of photobase generator IV (2.5 × 10 ⁻⁴ mol) with respect to PMAS, or a conventional photobase generator Orthonitrobenzyl ester (2.5 × 10 ⁻⁴ mol) was dissolved in 1.5 g of THF. Two drops of this solution were dropped on each glass substrate, pre-baked with a hot plate at 60 ° C. for 1 minute, covered with a glass substrate, and the gap was closed with a Teflon (registered trademark) sheet to form a film. Each film was irradiated with light for 400 seconds using an Hg-Xe lamp to examine whether bubbles were generated. The appearance after light irradiation is shown in FIG. 15 (conventional type) and FIG. 16 (photobase generator IV).

As shown in the following chemical reaction formula (5), carbon dioxide gas is generated by the progress of the chemical reaction in the conventional type, whereas in the case where the photobase generator IV is blended, it is shown in the following chemical reaction formula (6). As shown, carbon dioxide gas is not generated even when the chemical reaction proceeds. For this reason, as shown in FIGS. 15 and 16, it was confirmed that many bubbles were generated by light irradiation in the conventional type, whereas in the case where the photobase generator IV was blended, bubbles were generated. Was hardly seen. From this result, it was found that a cured film having higher film strength can be obtained with a system in which the photobase generator IV is blended.

It is a figure for demonstrating the photodegradation behavior in the solution of the photobase generator I. It is a figure for demonstrating the photodegradation behavior in the solid of the photobase generator I. It is a figure which shows IR peak change derived from the epoxy group of a photobase generator I / PGMA film | membrane. It is a figure which shows the relationship between the peak area ratio derived from the epoxy group of FIG. 3, and heating time. It is a figure for demonstrating the heating temperature dependence of a photobase generator I / PGMA film | membrane. It is a figure for demonstrating the heating time dependence of a photobase generator I / PGMA film | membrane. It is a figure for demonstrating the heating temperature dependence of a photobase generator II / PGMA film | membrane. It is a figure for demonstrating the heating time dependence of a photobase generator II / PGMA film | membrane. It is a figure which shows the relationship between the exposure energy in 254 nm, and a remaining film rate. It is a figure which shows the relationship between the exposure energy in 365 nm, and a residual film rate. It is IR spectrum change figure in a photobase generator IV / PGMA film | membrane. It is a figure which shows the relationship between the peak area ratio derived from the epoxy group of FIG. 11, and heating time. It is a figure for demonstrating the addition effect of a base proliferating agent. It is a figure for demonstrating the heating time dependence of a base growth agent. It is a figure which shows the external appearance (a) of the type | system | group which mix | blended the conventional photobase generator, and the external appearance (b) of the type | system | group which mix | blended the photobase generator IV.

Claims (5)

A photosensitive resin composition comprising a base-reactive resin and a photobase generator represented by the following general formula (1).
[In General Formula (1), Z represents an amino group. ] In the said General formula (1), Z is group represented by the following general formula (z1), The photosensitive resin composition of Claim 1 characterized by the above-mentioned.
[In General Formula (z1), R ₁ and R ₂ may be the same or different and each represents hydrogen or an organic group having 1 to 18 carbon atoms which may have a substituent. The organic group is selected from the group consisting of an alkyl group, a cycloalkyl group, an aryl group, and an arylalkyl group. ] In the said General formula (1), Z is group represented by the following general formula (z2), The photosensitive resin composition of Claim 1 characterized by the above-mentioned.
[In General Formula (z2), n and m are each independently an integer of 1 to 6, and R ₃ represents hydrogen, a hydrocarbon group, a hydrocarbon oxy group, or an acyl group. ]   The photosensitive resin composition according to claim 1, wherein the base-reactive resin is at least one selected from the group consisting of an epoxy resin, a silicon-containing resin, and a polyamic acid resin.   A photosensitive resin composition according to any one of claims 1 to 4 is coated on a support, dried, and exposed to a predetermined pattern, followed by heat treatment and development to form a cured resin pattern having a predetermined shape. A pattern forming method characterized in that it is obtained.