TWI759378B - Negative photosensitive resin composition, resin film and electronic device - Google Patents

Abstract

This invention provides a negative photosensitive resin composition comprising a polymer that is a copolymer, a crosslinking agent and a photosensitizer. Herein, the copolymer comprises a norbornene type structural unit substituted with a functional group containing a terminal unsaturated carbon double bond, a norbornene type structural unit substituted with a carboxyl group, and a structural unit derived from maleic anhydride, maleic anhydride derivative, maleimide or maleimide derivative.

Description

Negative photosensitive resin composition, resin film and electronic device

The present invention relates to a negative photosensitive resin composition, a resin film and an electronic device.

In the field of conventional negative-type photosensitive resin compositions, various techniques have been developed for the purpose of improving the accuracy of the resist pattern produced with the miniaturization of the pattern. As such a technique, the technique described in patent document 1 is mentioned, for example. According to this patent document 1, the radiation sensitive resin composition containing [A] polymer and [B] acid generator is described. In addition, it is described that the LWR (Line Width Roughness) indicating the small degree of instability of the line width is indicated by the fact that the polymer [A] has the structural unit (I) and the structural unit (II). Excellent performance and defect suppression (paragraph 0012 of Patent Document 1). It is described as follows: wherein, it is described that the structural unit (I) is derived from N-(tertiary butoxycarbonylmethyl)maleimide, N-(1-methyl-1-cyclopentyloxycarbonyl Methyl)maleimide, or N-(2-ethyl-2-adamantyloxycarbonylmethyl)maleimide structural unit. Furthermore, it is described that the structural unit (II) is a structural unit derived from 2-norbornene. [Prior Art Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2015-184458

[Problems to be Solved by Invention]

The present inventors produced a resin film formed from a negative photosensitive resin composition, and studied the durability of the resin film such as heat resistance and solvent resistance, and developability such as residual film ratio after development. As a result, it turned out that the resin film formed of the radiation-sensitive resin composition described in Patent Document 1 has room for further improvement from the viewpoints of durability and developability. Therefore, the subject of this invention is to provide the negative photosensitive resin composition which can improve durability and developability with a favorable balance, without impairing alkali developability. [How to solve the problem]

In order to improve the durability such as heat resistance and solvent resistance of the resin film formed from the negative photosensitive resin composition, and the developability such as the residual film ratio after development, the present inventors focused on the structural unit of the polymer of the copolymer. Were studied. As a result, it was found that the copolymer has norbornene-type structural units substituted with functional groups containing terminal unsaturated carbon double bonds, norbornene-type structural units substituted with carboxyl groups, derived from maleic anhydride, and maleic anhydride-derived structural units. It is a structural unit of maleimide, maleimide or maleimide derivative, which can improve durability and developability in a well-balanced manner without impairing alkali developability. Based on the above, the present inventors discovered that the durability and developability of a resin film using a negative photosensitive resin composition can be improved without impairing alkali developability by including a copolymer containing a specific structural unit. , thereby completing the present invention.

According to the present invention, there is provided a negative photosensitive resin composition comprising: a polymer of a copolymer represented by the following formula (1); a crosslinking agent; and a photosensitizer.

（式（1）中、 l及m表示聚合物中的莫耳含有率， l+m=1， A包含由下述式（A1）表示之結構單元、及 由下述式（A2）表示之結構單元， B包含由下述式（B1）、下述式（B2）、下述式（B3）、下述式（B4）、下述式（B5）或下述式（B6）表示之結構單元中的至少一種以上。）

(In the formula (1), l and m represent the molar content in the polymer, l+m=1, A includes a structural unit represented by the following formula (A1), and a structure represented by the following formula (A2) Structural unit, B includes a structure represented by the following formula (B1), the following formula (B2), the following formula (B3), the following formula (B4), the following formula (B5) or the following formula (B6) at least one of the units.)

（式（A1）中，R₁ 、R₂ 、R₃ 及R₄ 分別獨立地為氫或碳數1～30的有機基，R₁ 、R₂ 、R₃ 及R₄ 中包含至少一個末端不飽和碳雙鍵。n為0、1或2。）

(In formula (A1), R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen or an organic group having 1 to 30 carbon atoms, and R ₁ , R ₂ , R ₃ and R ₄ include at least one terminal Saturated carbon double bond. n is 0, 1 or 2.)

（式（A2）中，R₅ 、R₆ 及R₇ 分別獨立地為氫或碳數1～30的有機基，n為0、1或2。）

(In formula (A2), R ₅ , R ₆ and R ₇ are each independently hydrogen or an organic group having 1 to 30 carbon atoms, and n is 0, 1 or 2.)

（式（B1）中，R₈ 獨立地為碳數1～30的有機基。）

(In formula (B1), R ₈ is independently an organic group having 1 to 30 carbon atoms.)

（式（B2）中，R₉ 及R₁₀ 分別獨立地為碳數1～30的有機基。）

(In formula (B2), R ₉ and R ₁₀ are each independently an organic group having 1 to 30 carbon atoms.)

（式（B6）中，R₁₁ 獨立地為碳數1～30的有機基。）

(In formula (B6), R ₁₁ is independently an organic group having 1 to 30 carbon atoms.)

Moreover, according to this invention, the resin film which consists of the said negative photosensitive resin composition is provided.

Moreover, according to this invention, the electronic device provided with the said resin film is provided. [Effect of invention]

According to the present invention, there is provided a negative photosensitive resin composition capable of improving the durability and developability of a resin film formed from the negative photosensitive resin composition without impairing the alkali developability.

Hereinafter, the present embodiment will be described using the drawings as appropriate. In addition, in all drawings, the same code|symbol is attached|subjected to the same component, and description is abbreviate|omitted. In addition, in this embodiment, A-B means A or more and B or less.

The outline of the negative photosensitive resin composition of this embodiment is demonstrated. The negative photosensitive resin composition of the present embodiment includes: a polymer of a copolymer represented by the following formula (1); a crosslinking agent; and a photosensitizer.

（式（1）中， l及m表示聚合物中的莫耳含有率， l+m=1， A包含由下述式（A1）表示之結構單元、及 由下述式（A2）表示之結構單元， B包含由下述式（B1）、下述式（B2）、下述式（B3）、下述式（B4）、下述式（B5）或下述式（B6）表示之結構單元中的至少一種以上。）

(In the formula (1), l and m represent the molar content in the polymer, l+m=1, A includes a structural unit represented by the following formula (A1), and a structure represented by the following formula (A2) Structural unit, B includes a structure represented by the following formula (B1), the following formula (B2), the following formula (B3), the following formula (B4), the following formula (B5) or the following formula (B6) at least one of the units.)

（式（A1）中，R₁ 、R₂ 、R₃ 及R₄ 分別獨立地為氫或碳數1～30的有機基，R₁ 、R₂ 、R₃ 及R₄ 中包含至少一個末端不飽和碳雙鍵。n為0、1或2。）

(In formula (A1), R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen or an organic group having 1 to 30 carbon atoms, and R ₁ , R ₂ , R ₃ and R ₄ include at least one terminal Saturated carbon double bond. n is 0, 1 or 2.)

（式（A2）中，R₅ 、R₆ 及R₇ 分別獨立地為氫或碳數1～30的有機基，n為0、1或2。）

(In formula (A2), R ₅ , R ₆ and R ₇ are each independently hydrogen or an organic group having 1 to 30 carbon atoms, and n is 0, 1 or 2.)

（式（B1）中，R₈ 獨立地為碳數1～30的有機基。）

(In formula (B1), R ₈ is independently an organic group having 1 to 30 carbon atoms.)

（式（B2）中，R₉ 及R₁₀ 分別獨立地為碳數1～30的有機基。）

(In formula (B2), R ₉ and R ₁₀ are each independently an organic group having 1 to 30 carbon atoms.)

（式（B6）中，R₁₁ 獨立地為碳數1～30的有機基。）

(In formula (B6), R ₁₁ is independently an organic group having 1 to 30 carbon atoms.)

According to this embodiment, the copolymer comprises norbornene-type structural units substituted by functional groups containing terminal unsaturated carbon double bonds, norbornene-type structural units substituted by carboxyl groups, and derived from maleic anhydride and maleic anhydride. compound, maleimide or the structural unit of maleimide derivatives.

The negative photosensitive resin composition of the present embodiment generates radicals due to exposure by a photosensitizer, and causes a radical chain reaction to be cured. In the negative photosensitive resin composition of the present embodiment, it is considered that the terminal unsaturated carbon double bond of the norbornene side chain of the copolymer contributes to the radical chain reaction. Therefore, although the detailed mechanism is not clear, it is presumed that the negative photosensitive resin composition of the present embodiment can improve the crosslinking structure formed by the radical chain reaction compared with the conventional negative photosensitive resin composition. and can further limit the mobility of molecular chains. Therefore, the heat resistance of the cured film of a negative photosensitive resin composition, durability, such as solvent resistance, and developability, such as the residual film ratio after image development, can be improved.

Moreover, about the negative photosensitive resin composition of this embodiment, as mentioned above, for example, a part is exposed and hardened, and a part is unexposed and is not hardened on the other hand. Then, the uncured unexposed portion is removed by an alkaline solution, and it can be used for a desired application. In the copolymer of the present embodiment, the norbornene-type structural unit substituted with a functional group containing a terminal unsaturated carbon double bond is formed by substituting a part of the carboxyl-substituted norbornene-type structural unit. Then, a part of the carboxyl group-substituted norbornene-type structural unit remains in the copolymer as it is. Thereby, the copolymer of this embodiment contains the norbornene type structural unit which has a carboxyl group. Thereby, when removing the unexposed part, the alkali solubility can be improved. Also, by the copolymer containing a structural unit derived from maleic anhydride, a maleic anhydride derivative, maleimide, or a maleimide derivative, the alkali solubility can be appropriately controlled. In the conventional negative-type photosensitive resin composition, when the durability and developability of the cured film of the negative-type photosensitive resin composition are improved, there is a possibility that the alkali solubility is lowered by simply setting the structure to be easily cross-linked. bad condition. However, in the negative-type photosensitive resin composition of the present embodiment, the copolymer includes norbornene-type structural units substituted with functional groups containing terminal unsaturated carbon double bonds, norbornene-type structural units substituted with carboxyl groups And structural units derived from maleic anhydride, maleic anhydride derivatives, maleimide or maleimide derivatives can improve the durability and developability of the cured film without reducing the alkali solubility. From the above, the negative photosensitive resin composition of the present embodiment can improve the durability and developability of the resin film formed from the negative photosensitive resin composition without impairing the alkali developability.

Hereinafter, each component of the negative photosensitive resin composition of this embodiment is demonstrated. The negative photosensitive resin composition of this embodiment contains a polymer, a crosslinking agent, and a photosensitizer.

(Polymer) First, the polymer of this embodiment is demonstrated. The polymer of the present embodiment is a copolymer represented by the following formula (1). In addition, the following formula (1) does not limit the arrangement of the copolymer. As the arrangement of the copolymers, for example, random copolymers, alternating copolymers, block copolymers, periodic copolymers, and the like can be selected.

（式（1）中， l及m表示聚合物中的莫耳含有率， l+m=1， A包含由下述式（A1）表示之結構單元、及 由下述式（A2）表示之結構單元， B包含由下述式（B1）、下述式（B2）、下述式（B3）、下述式（B4）、下述式（B5）或下述式（B6）表示之結構單元中的至少一種以上。）

(In the formula (1), l and m represent the molar content in the polymer, l+m=1, A includes a structural unit represented by the following formula (A1), and a structure represented by the following formula (A2) Structural unit, B includes a structure represented by the following formula (B1), the following formula (B2), the following formula (B3), the following formula (B4), the following formula (B5) or the following formula (B6) at least one of the units.)

The composition ratio of the structural unit of the said A and the structural unit of the said B in a copolymer is demonstrated. Let the molar content (mol%) of the structural unit of A above be 1, the molar content (mol%) of the structural unit of B above be m, and let l+m=1, the numerical range of l is 0.1 ≤l≤0.9. In addition, the numerical range of m is 0.1≤m≤0.9. Thereby, the improvement of heat resistance, the improvement of solvent resistance, and the improvement of the residual film rate after image development can be aimed at by fully including the structural unit of the said A and the structural unit of the said B.

In the copolymer represented by the above formula (1), A includes a structural unit represented by the following formula (A1) derived from a norbornene-type monomer substituted with a functional group containing a terminal unsaturated carbon double bond, and the following The formula (A2) represents a structural unit derived from a carboxyl group-substituted norbornene-type monomer. When the copolymer contains the structural unit represented by the following formula (A1), as described above, the heat resistance, solvent resistance, and residual film ratio after image development can be improved when a negative photosensitive resin composition is formed. Moreover, when a copolymer contains the structural unit represented by following formula (A2), as mentioned above, the alkali solubility at the time of making a negative photosensitive resin composition can be adjusted.

（式（A1）中，R₁ 、R₂ 、R₃ 及R₄ 分別獨立地為氫或碳數1～30的有機基，R₁ 、R₂ 、R₃ 及R₄ 中包含至少一個末端不飽和碳雙鍵。n為0、1或2。）

(In formula (A1), R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen or an organic group having 1 to 30 carbon atoms, and R ₁ , R ₂ , R ₃ and R ₄ include at least one terminal Saturated carbon double bond. n is 0, 1 or 2.)

（式（A2）中，R₅ 、R₆ 及R₇ 分別獨立地為氫或碳數1～30的有機基，n為0、1或2。）

(In formula (A2), R ₅ , R ₆ and R ₇ are each independently hydrogen or an organic group having 1 to 30 carbon atoms, and n is 0, 1 or 2.)

In the present embodiment, the hydrogen or the organic group having 1 to 30 carbon atoms constituting R ₁ to R ₄ in the above formula (A1) and R ₅ to R ₇ in the above formula (A2) may include optional One or more atoms selected from O, N, S, P, and Si. Furthermore, in the present embodiment, none of the organic groups constituting R ₁ , R ₂ , R ₃ and R ₄ can have an acidic functional group. Thereby, the acid value in the polymer can be easily controlled.

Moreover, in this embodiment, R ₁ to R ₄ in the above formula (A1) and R ₅ to R ₇ in the above formula (A2) are each independently hydrogen or an organic group having 1 to 30 carbon atoms, each independently Preferably, it is hydrogen or an organic group with 1 to 10 carbon atoms, it is more preferably hydrogen or an organic group with 1 to 5 carbon atoms, and it is even more preferable to be hydrogen or an organic group with 1 to 3 carbon atoms. good.

In the present embodiment, examples of the organic groups constituting R ₁ to R ₄ in the above formula (A1) and R ₅ to R ₇ in the above formula (A2) include an alkyl group, an alkenyl group, an alkynyl group, Alkylene, aryl, aralkyl, alkaryl, cycloalkyl and heterocyclyl. Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tertiary butyl, tertiary butyl, pentyl, neopentyl, hexyl, and heptyl. , octyl, nonyl and decyl. As an alkenyl group, an allyl group, a pentenyl group, and a vinyl group are mentioned, for example. As an alkynyl group, an ethynyl group is mentioned. As an alkylene group, a methylene group and a hexylene group are mentioned, for example. As an aryl group, a tolyl group, a xylyl group, a phenyl group, a naphthyl group, and an anthracenyl group are mentioned, for example. As an aralkyl group, a benzyl group and a phenethyl group are mentioned, for example. As a cycloalkyl group, an adamantyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group are mentioned, for example. As a heterocyclic group, an epoxy group and an oxetanyl group are mentioned, for example.

In the present embodiment, in the above formula (A1), R ₁ , R ₂ , R ₃ and R ₄ contain at least one terminal unsaturated carbon double bond. Thereby, in a negative photosensitive resin composition, the structural unit which contributes to a crosslinking structure by radicalization at the time of exposure can be increased. Other than that, the detailed mechanism is not clear, but the movement of the polymer chain can be more strongly restricted by the side chain of the norbornene-type structural unit contributing to the cross-linked structure. Thereby, the heat resistance, solvent resistance, and residual film ratio after image development of the negative photosensitive resin composition can be improved in a well-balanced manner. In addition, in the present embodiment, it is not particularly limited that R ₁ , R ₂ , R ₃ and R ₄ contain two or more terminal unsaturated carbon double bonds. Among R ₁ to R ₄ , those containing a terminal unsaturated carbon double bond are preferably any of R ₁ to R ₄ . Thereby, functional groups containing a terminal unsaturated carbon double bond do not form a steric hindrance to each other, which is preferable from the viewpoint of being able to form a preferable cross-linked structure.

In the above formula (A1) and formula (A2), n is 0, 1 or 2, n is 0 or 1, and n is 0, respectively.

Since R ₁ , R ₂ , R ₃ and R ₄ contain terminal unsaturated carbon double bonds, it is preferable to include a structure represented by the following formula (E1). Among the structures represented by the formula (E1), it is more preferable to include a structure represented by the following formula (E2). Thereby, a preferable crosslinked structure can be formed. Therefore, the heat resistance, solvent resistance, and residual film ratio after image development of the negative photosensitive resin composition can be improved in a well-balanced manner.

（式（E1）中，R_e 獨立地為氫或碳數1～10的有機基。）

(In formula (E1), _Re is independently hydrogen or an organic group having 1 to 10 carbon atoms.)

（式（E2）中，R_e 獨立地為氫或碳數1～10的有機基。）

(In formula (E2), _Re is independently hydrogen or an organic group having 1 to 10 carbon atoms.)

In the above formulae (E1) and (E2), R _e is independently hydrogen or an organic group having 1 to 10 carbon atoms, preferably hydrogen or an organic group having 1 to 7 carbon atoms, and hydrogen or an organic group having 1 to 5 carbon atoms. The group is more preferred, hydrogen or an organic group having 1 to 3 carbon atoms is even more preferred, and hydrogen or an organic group having 1 carbon atoms is particularly preferred.

Specific examples of R ₁ , R ₂ , R ₃ and R ₄ having terminal unsaturated carbon double bonds include vinyl groups, vinylene groups, acrylic groups, methacrylic groups, acrylate groups, and methacrylate groups. Wait. Among these, R ₁ , R ₂ , R ₃ and R ₄ containing terminal unsaturated carbon double bonds are at least one selected from the group consisting of acrylic group, methacrylic group, acrylate group and methacrylate group Preferably, it is an acrylate group or a methacrylate group.

The lower limit of the content of the structural unit represented by the above formula (A1) in the copolymer is preferably 0.1 mol or more, more preferably 0.2 mol or more, relative to 1 mol of the structural unit represented by the above formula (A2). Thereby, a preferable crosslinked structure can be formed. In addition, the upper limit of the content of the structural unit represented by the above formula (A1) in the copolymer is preferably 3.0 mol or less, more preferably 2.0 mol or less, and 1.0 mol relative to 1 mol of the structural unit represented by the above-mentioned formula (A2). The following is more preferable, and 0.7 mol or less is particularly preferable. Thereby, alkali solubility can be preferably exhibited. In addition, in the present embodiment, the content of the structural unit represented by the above formula (A1) with respect to 1 mol of the structural unit represented by the above formula (A1) in the polymer can be determined, for example, by using a nuclear magnetic resonance apparatus (for example, JEOL Ltd. 1H-NMR measurement performed by the system) was used for evaluation.

In addition, in the copolymer represented by the above formula (1), B includes the following formula (B1), the following formula (B2), the following formula (B3), the following formula (B4), the following formula (B5) ) or at least one of the structural units represented by the following formula (B6). Among these, it is preferable to include a structural unit represented by the following formula (B5) or the following formula (B6). Thereby, alkali solubility can be improved, and developability can be improved. Furthermore, it is more preferable to include the following formula (B6) in the following formula (B5) or the following formula (B6). Thereby, the alkali solubility at the time of making a negative photosensitive resin composition can be adjusted, and heat resistance can be improved further.

（式（B1）中，R₈ 獨立地為碳數1～30的有機基。）

(In formula (B1), R ₈ is independently an organic group having 1 to 30 carbon atoms.)

（式（B2）中，R₉ 及R₁₀ 分別獨立地為碳數1～30的有機基。）

(In formula (B2), R ₉ and R ₁₀ are each independently an organic group having 1 to 30 carbon atoms.)

（式（B6）中，R₁₁ 獨立地為碳數1～30的有機基。）

(In formula (B6), R ₁₁ is independently an organic group having 1 to 30 carbon atoms.)

In this embodiment, it is preferable that B contains the structural unit represented by the said formula (B5) in addition to the structural unit represented by the said formula (B6). By including the structural units represented by the above formula (B6) and the above formula (B5) at the same time, when a negative photosensitive resin composition is prepared, the alkali solubility can be improved, and the sensitivity can be further improved. Thereby, when a negative photosensitive resin composition is used, in addition to improving heat resistance, solvent resistance, and the residual film ratio after image development, it is possible to maintain excellent sensitivity at the same time.

In the present embodiment, the organic group having 1 to 30 carbon atoms constituting R ₈ to R ₁₁ in the above-mentioned formula (B1), formula (B2) and formula (B6) may include in its structure a group selected from O, N, One or more atoms of S, P and Si. Furthermore, in the present embodiment, none of the organic groups constituting R ₈ to R ₁₁ can have an acidic functional group. Thereby, the acid value in the polymer can be easily controlled.

Moreover, in the present embodiment, R ₈ to R ₁₁ in the above-mentioned formula (B1), formula (B2) and formula (B6) are each independently an organic group having 1 to 30 carbon atoms, and each independently is a carbon number of 1 The organic group of ~10 is preferable, the organic group of each independently having 1 to 5 carbon atoms is more preferable, and the organic group of each independently having 1 to 3 carbon atoms is even more preferable.

In the present embodiment, as the organic groups constituting R ₈ to R ₁₁ in the above formula (B1), formula (B2) and formula (B6), R ₁ to R ₄ in the above formula (A1) can be used and the same organic groups as the organic groups of R ₅ to R ₇ in the above formula (A2).

The upper limit of Mw (weight average molecular weight) of the polymer of the present embodiment is, for example, 30,000 or less, preferably 20,000 or less, more preferably 14,000 or less, and even more preferably 10,000 or less. Thereby, a more appropriate cross-linked structure can be produced by improving the mobility of the molecular chain. Moreover, the lower limit of the polymer Mw is, for example, 1500 or more, preferably 2000 or more, and more preferably 3000 or more. Thereby, when exposing a negative photosensitive resin composition, a crosslinked structure can be formed rapidly. Therefore, the sensitivity of the negative photosensitive resin composition can be improved.

Further, the upper limit of the dispersity of the polymer of the present embodiment, that is, Mw (weight average molecular weight)/Mn (number average molecular weight) is, for example, 2.5 or less, preferably 2.2 or less, and more preferably 2.0 or less. Thereby, the width|variety of the molecular weight distribution of a polymer can be made small, and the same crosslinked structure can be formed in the whole negative photosensitive resin composition. Therefore, the physical properties can be made uniform throughout the cured product of the negative photosensitive resin composition. Moreover, the lower limit value of Mw/Mn can be set to 1.0 or more, for example, and can be set to 1.5 or more. In addition, the closer Mw/Mn is to monodispersity, the better. In addition, Mw/Mn represents the degree of dispersion of the width of the molecular weight distribution. By setting the Mw/Mn of the polymer to be in the above range, the shape of the resin film formed from the polymer-containing resin composition can be improved. In addition, at the same time, when the low-molecular-weight components of the polymer are reduced as described above, this effect is particularly evident.

In addition, as the weight average molecular weight (Mw), the number average molecular weight (Mn) and the molecular weight distribution (Mw/Mn), polystyrene obtained by, for example, a calibration curve of standard polystyrene (PS) obtained by GPC measurement is used. Converted value. The measurement conditions are, for example, as follows. Gel permeation chromatography apparatus HLC-8320GPC manufactured by Tosoh Corporation Column: TSK-GEL Supermultipore HZ-M manufactured by Tosoh Corporation Detector: RI detector for liquid chromatography Measurement temperature: 40°C Solvent: THF Test Sample concentration: 2.0mg/ml

The alkali dissolution rate of the polymer in the present embodiment is, for example, 500 angstroms/sec or more and 20,000 angstroms/sec or less. The alkali dissolution rate of the polymer is calculated by, for example, dissolving the polymer in propylene glycol monomethyl ether acetate, adjusting it to a polymer solution with a solid content of 20% by weight, and then applying it to a silicon wafer by spin coating , soft-bake the polymer solution at 110°C for 100 seconds to obtain a polymer film, immerse the polymer film in a 2.38% aqueous tetramethylammonium hydroxide solution at 23°C, and measure until the aforementioned polymer is visually The time until the film disappears. By setting the alkali dissolution rate of the polymer to be 500 angstroms/sec or more, the throughput in the development step by an alkali developer can be improved. Moreover, by making the alkali dissolution rate of a polymer into 20,000 angstroms/sec or less, the residual film rate after the developing process by an alkali developing solution can be improved. Therefore, the reduction of the film by the lithography step can be suppressed.

(Manufacturing method of a polymer) The polymer of this embodiment is manufactured as follows, for example. At least comprising: polymerizing the monomer A and the monomer B, and polymerizing the polymerization step of the copolymer 1 (treatment S1); then, replacing the monomer A from the copolymer 1 with a compound having a terminal unsaturated carbon double bond. carboxyl groups to obtain a substitution step of copolymer 2 (treatment S2 ); and a low molecular weight removal step of removing low molecular weight components from copolymer 2 to obtain a polymer (treatment S3 ). When the monomer B contains maleic anhydride, after the polymerization step (treatment S1) and before the low molecular weight removal step (treatment S3), it may also include: a ring-opening step ( Treatment S'1); then, a cleaning step for removing residual metal components (treatment S'2). Hereinafter, the details of each step will be described.

(Polymerization Step (Treatment S1 )) First, a carboxyl group-substituted norbornene-type monomer, and maleic anhydride, maleimide, or a maleimide derivative are prepared. In the copolymer represented by the above formula (1), the carboxyl group-substituted norbornene-type monomer (hereinafter, referred to as monomer A) serves as a source of the structural unit represented by A. In addition, one or two or more monomers (hereinafter referred to as monomers B) selected from the group consisting of maleic anhydride, maleimide, and maleimide derivatives have a structure represented by B. The source of the unit.

Monomer A is represented by the following formula (2). In the following formula (2), R ₅ to R ₇ can be the same as R ₅ to R ₇ in the above formula (A2).

（式（2）中，R₅ 、R₆ 及R₇ 分別獨立地為氫或碳數1～30的有機基，n為0、1或2。）

(In formula (2), R ₅ , R ₆ and R ₇ are each independently hydrogen or an organic group having 1 to 30 carbon atoms, and n is 0, 1 or 2.)

Specific examples of the carboxyl-substituted norbornene-type monomer represented by the above formula (2) include 5-norbornene-2-carboxylic acid, 5-norbornene-2,3-dicarboxylic acid, and Tetracyclodecene carboxylic acid, etc. As the carboxyl group-substituted norbornene-type monomer, one or two or more of these can be used. Among them, it is preferable to use 5-norbornene-2-carboxylic acid from the viewpoint of improving heat resistance.

Monomer B is one or more monomers selected from the group consisting of maleic anhydride, maleimide and maleimide derivatives, and is selected from maleimide and maleimide One or two or more monomers from the group consisting of amine derivatives are preferred. By using the maleimide derivative, it is possible to improve heat resistance, residual film rate after curing, and solvent resistance. Moreover, by using maleimide and a maleimide derivative in combination, the alkali dissolution rate of the negative photosensitive resin composition can be increased, and the sensitivity can be further improved. The maleimide derivative is shown in the following formula (3).

（式（3）中，R₁₁ 獨立地為碳數1～30的有機基。）

(In formula (3), R ₁₁ is independently an organic group having 1 to 30 carbon atoms.)

Examples of maleimide derivatives represented by the above formula (3) include N-straight-chain alkylmaleimide such as N-methylmaleimide and N-ethylmaleimide. Amines; N-branched alkylmaleimides such as N-isopropylmaleimide; N-cycloalkylmaleimides such as N-cyclohexylmaleimide; N-phenylmaleimide N-arylmaleimide such as lyimide, N-naphthylmaleimide, etc. Among these, straight-chain N-alkylmaleimides, branched alkylmaleimides or N-cycloalkylmaleimides are preferably used, including N-cycloalkylmaleimides Amines are better. As N-cycloalkylmaleimide, N-cyclohexylmaleimide is preferably used. Thereby, the heat resistance, the residual film rate after curing, and the solvent resistance can be improved.

then. The copolymer 1 was synthesized by addition-polymerizing the monomer A and the monomer B. The method of addition polymerization is not particularly limited, but in this embodiment, the copolymer 1 is synthesized by radical polymerization. The copolymer 1 having the structural unit derived from the monomer A and the structural unit derived from the monomer B can be synthesized by addition polymerization. Here, the structural unit derived from the monomer A is shown in the following formula (A2). Furthermore, by using maleic anhydride, maleimide, and a maleimide derivative as the monomer B, it is possible to obtain compounds having the following formulae (B3), the following formula (B5), the following Copolymer 1 of the structural unit of formula (B6).

（式（A2）中，R₅ 、R₆ 及R₇ 分別獨立地為氫或碳數1～30的有機基，n為0、1或2。）

(In formula (A2), R ₅ , R ₆ and R ₇ are each independently hydrogen or an organic group having 1 to 30 carbon atoms, and n is 0, 1 or 2.)

（式（B6）中，R₁₁ 獨立地為碳數1～30的有機基。）

(In formula (B6), R ₁₁ is independently an organic group having 1 to 30 carbon atoms.)

The molar ratio of the monomer A and the monomer B is preferably 0.5:1 to 1:0.5. Among them, from the viewpoint of controlling the molecular structure, a molar ratio of 1:1 is preferable. The monomer A, the monomer B, and the polymerization initiator are dissolved in a solvent, and then addition polymerization is performed by heating for a predetermined time. The heating temperature is, for example, 50 to 80° C., and the heating time is 10 to 20 hours.

As the polymerization initiator, one or two or more of azo compounds and organic peroxides can be used. Examples of the azo compound include azobisisobutyronitrile (AIBN), 2,2'-azobis(2-methylpropionic acid) dimethyl ester, 1,1'-azobis(cyclohexylmethyl) Nitrile) (ABCN), among these, any one or more can be used. In addition, examples of organic peroxides include hydrogen peroxide, di-tert-butyl peroxide (DTBP), benzoyl peroxide (BPO), and methyl ethyl ketone peroxide (MEKP). Among them, any one or more can be used.

The amount (molar number) of the polymerization initiator is preferably the total number of moles of the carboxyl-substituted norbornene-type monomer that is the source of the structural unit of A and the monomer that is the source of the structural unit of B above 1% to 10% is ideal. The weight-average molecular weight (Mw) of the polymer obtained can be adjusted to 5,000 to 30,000 by appropriately setting the amount of the polymerization initiator within the aforementioned range, and by appropriately setting the reaction temperature and reaction time.

As the solvent, for example, one or two or more of diethyl ether, tetrahydrofuran, toluene, and the like can be used.

By this polymerization step, the copolymer 1, which is a copolymer of the monomer A and the monomer B, can be polymerized. The arrangement of the copolymer 1 is not particularly limited, and may be any of a random copolymer, an alternating copolymer, a block copolymer, and a periodic copolymer. When the copolymer 1 uses, for example, the monomer represented by the above formula (2) as the monomer A and the monomer represented by the above formula (3) as the monomer B, it has a structure represented by the following formula (4) copolymers of units.

（在式（4）中，R₅ ～R₇ 與上述式（A2）相同。又，R₁₁ 與上述式（3）相同。）

(In the formula (4), R ₅ to R ₇ are the same as the above formula (A2). In addition, R ₁₁ is the same as the above formula (3).)

In the copolymer 1, the functional groups of R ₅ to R ₇ derived from the monomer A may be different or the same in each repeating unit. Of these, the same is preferable. Thereby, the precision of patterning of a negative photosensitive resin composition can be improved.

(Substitution step (S2)) Next, in the obtained copolymer 1, a part of the carboxyl groups of the structural unit represented by the above formula (A2) is substituted by a compound having a terminal unsaturated carbon double bond to prepare a copolymer 2.

The method for synthesizing the copolymer 2 in place of the copolymer 1 is not particularly limited, and for example, it can be carried out by the following method. The copolymer 2 is synthesized by dissolving the above-mentioned copolymer 1 and the compound having a terminal unsaturated carbon double bond in a solvent and heating for a predetermined time to perform a substitution reaction. Here, the heating temperature is, for example, 50 to 100° C., and the heating time is 2 to 20 hours. Thereby, a repeating unit derived from the monomer A, a repeating unit in which the monomer A is substituted with a compound having a terminal unsaturated carbon double bond, and a structural unit derived from the monomer B can be obtained in the structural unit of A. The structural unit in which the monomer A is substituted with a compound having a terminal unsaturated carbon double bond is shown in the following formula (A1).

（式（A1）中，R₁ 、R₂ 、R₃ 及R₄ 分別獨立地為氫或碳數1～30的有機基，R₁ 、R₂ 、R₃ 及R₄ 中包含至少一個末端不飽和碳雙鍵。n為0、1或2。）

(In formula (A1), R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen or an organic group having 1 to 30 carbon atoms, and R ₁ , R ₂ , R ₃ and R ₄ include at least one terminal Saturated carbon double bond. n is 0, 1 or 2.)

As the compound having the above-mentioned terminal unsaturated carbon double bond, an acrylic compound is preferably used. Examples of the acrylic compound include glycidyl methacrylate, glycidyl acrylate, 4-hydroxybutyl acrylate glycidyl ether, and hydroxyethyl methacrylate. Among these, it is preferable to use glycidyl methacrylate.

As the solvent, for example, one or two or more of diethyl ether, tetrahydrofuran, toluene, and the like can be used.

In the copolymer 2, for example, 5 mol% or more of the structural units represented by the above-mentioned formula (A1) are preferably substituted with respect to all the structural units represented by A, more preferably 10 mol% or more, and 15 mol% or more. More preferably, it is even more preferable to substitute 20 mol% or more. By setting the substitution ratio in this way, the terminal unsaturated carbon double bond derived from the norbornene unit can be appropriately cross-linked. Thereby, the heat resistance, residual film ratio, and solvent resistance of the negative photosensitive resin composition containing the copolymer 2 can be improved.

Here, the repeating unit substituted for a part of the repeating unit derived from the carboxyl group-substituted norbornene-type monomer can be identified by the spectral data measured by 1 H-NMR.

In addition, the substitution rate of the carboxyl group by the acrylic compound can be measured as follows. 1H-NMR measurement was performed on the polymer solution of Copolymer 2. Regarding the spectral data obtained by the 1H-NMR measurement, the signal integral value X per unit proton derived from the carboxyl group, the per unit proton derived from the terminal unsaturated carbon double bond formed by the added acrylic compound were calculated Signal integral value Y. The substitution rate can be calculated by the following equation using the above-mentioned signal integral value. Substitution rate (%)=Y/(X+Y)×100

(Low Molecular Weight Removal Step ( S3 )) Next, the organic layer containing the copolymer 2 and low molecular weight components such as residual monomers and oligomers is concentrated, and then dissolved again in an organic solvent such as THF. Then, hexane and methanol were added to the solution to coagulate and precipitate the polymer containing the copolymer 2. Here, residual monomers, oligomers, polymerization initiators, and the like are included as low molecular weight components. Next, filtration was performed and the obtained coagulation was dried. In this way, a polymer containing the copolymer 2 from which low molecular weight components have been removed as a main component (main product) can be obtained. In the present embodiment, in this low molecular weight component removal step (treatment S3 ), the extraction operation is repeatedly performed until the content rate of low nuclear bodies having a molecular weight of 1000 or less in the copolymer 2 becomes 1% or less. Thereby, the quantity of the low molecular weight component in a 1st polymer can be reduced to a sufficient degree, and the pattern deformation|transformation of a film at the time of hardening can be suppressed.

in addition. When the monomer B contains maleic anhydride, the ring-opening step (S'1) and the washing step (S'2) may be performed after the above-mentioned polymerization step (S1) and before the above-mentioned low-molecular-weight removal step (S3). It will be described below.

(Ring-opening step (S'1)) The remaining repeating units are opened while part of the repeating units derived from maleic anhydride in the obtained copolymer 1 or copolymer 2 are closed. ring. Thereby, the amount of carboxyl groups in the copolymer 1 can be adjusted. That is, the acid value of the produced polymer can be controlled. In this embodiment, for example, 50% or more of the repeating units derived from maleic anhydride in the copolymer 1 or the copolymer 2 are not ring-opened, and the cyclic structure (anhydride ring) of the remaining repeating units is not opened. ) open loop. That is, the ring opening rate of the copolymer 1 is, for example, less than 50%. Among them, it is preferable that 60% or more and 90% or less of the total number of repeating units derived from the cyclic structure of maleic anhydride in the copolymer 1 are not ring-opened.

Here, the ring opening ratio of the repeating unit derived from maleic anhydride can be measured in the following manner. Measure the IR absorption intensity (A1) of (C=O) in the acid anhydride structure of copolymer 1 or copolymer 2 before ring opening, and use the IR absorption intensity (A2) of the (C=O) in the acid anhydride structure after ring opening ), and calculate the open loop rate by the following formula. Ring opening rate (%)=((A1-A2)/A1)×100 In addition, acetonitrile was used as an internal standard substance.

Specifically, any one of (A) an alkali metal alkoxide (B) alcohol and an alkali metal hydroxide as an alkali is added to the reaction liquid in which the copolymer 1 is polymerized in the polymerization step. , and an organic solvent such as methyl ethyl ketone (MEK) was further added, and the mixture was stirred at 40 to 50° C. for 1 to 5 hours to obtain a reaction solution L1. In the reaction liquid L1, a part of the anhydride ring of the maleic anhydride-derived repeating unit of the copolymer 1 is ring-opened, and a part of the terminal formed by the ring-opening is esterified. In addition, the remaining terminals are not esterified, but have a metal salt structure.

In the present embodiment, the molar number of the metal alkoxide or the alkali metal hydroxide is preferably 50% or less of the molar number of the maleic anhydride used in the polymerization step. Among them, the molar number of the metal alkoxide or alkali metal hydroxide is preferably 40% or less of the molar number of maleic anhydride used in the polymerization step and 10% or more, more preferably 30% or less. . By setting it in this way, the amount of a metal alkoxide or an alkali metal hydroxide can be reduced, and the alkali metal concentration in the polymer finally obtained can be reduced. By reducing the alkali metal concentration in the polymer, the migration of metal ions during the formation of devices using the polymer can be suppressed.

The metal alkoxide is preferably represented by M(OR ₈ ) (M is a monovalent metal, and R ₈ is an organic group having 1 to 18 carbon atoms.) Examples of the metal M include alkali metals, and among them, sodium is preferable from the viewpoint of handleability. Examples of R ₈ include the same ones as R ₈ in the above formula (B1). Moreover, as a metal alkoxide, it is also possible to use two or more different ones. However, from the viewpoint of production stability, it is preferable to use one kind of metal alkoxide.

On the other hand, as described above, the maleic anhydride-derived structure of the copolymer 1 or the copolymer 2 may be ring-opened in the presence of the (B) alcohol and the alkali metal hydroxide as the base. As the alkali metal hydroxide, sodium hydroxide is preferable from the viewpoint of workability. As the alcohol, a monohydric alcohol (R ₈ OH) is preferable. The aforementioned ones can be used as R ₈ of the organic group. In addition, the carbon number coefficient of R ₈ is preferably 30 or less.

The repeating unit derived from maleic anhydride which is ring-opened in this ring-opening step (treatment S'1) becomes a structure represented by the following formula (6), and becomes a structure having a salt moiety of a carboxyl group.

In addition, when the copolymer is ring-opened with (A) the metal alkoxide as the base or (B) the alcohol and the hydroxide of the alkali metal as the base, although only a small amount is used, the following formula ( 8), the structure represented by the following formula (B2). In addition, in the following formula (B2), R ₉ and R ₁₀ may be the same as the above-mentioned R ₈ .

Next, by adding an acidic aqueous solution such as hydrochloric acid or formic acid to the reaction liquid L1, the copolymer 1 or the copolymer 2 is acid-treated to replace the metal ion (Na+) with a proton (H+). The structural units represented by the above formulae (6) and (8) become structural units represented by the following (B1) and (B4), respectively, by proton substitution.

In this ring-opening step (treatment S'1), it is preferable that 50% or more of the repeating units derived from maleic anhydride in the copolymer 1 or the copolymer 2 are not ring-opened. In the copolymer 2, as described above, a metal (eg, Na) is bonded to one terminal formed by ring-opening of the maleic anhydride ring, but by keeping more than 50% of the repeating units from ring-opening, the polymerization as a product can be reduced. The amount of metal contained in the material. Thereby, the amount of alkali metal in the polymer finally obtained in this embodiment can be reduced, and the desired characteristic can be exhibited in the negative photosensitive resin composition using this polymer.

(Washing Step (Treatment S'2)) The ring-opening step (Treatment S'1) obtained by the above-described step is carried out with a mixture of water and an organic solvent (eg, methyl ethyl ketone) containing the ring-opened The solution of copolymer 1 or copolymer 2 is washed to remove residual metal components. The ring-opened copolymer 1 or copolymer 2, residual monomers and oligomers move to the organic layer. Then, the water layer is removed (first wash). Then, a mixture of water and an organic solvent (eg, methyl ethyl ketone) is added to the organic layer again for washing (second washing). In the present embodiment, the above-described cleaning step (treatment S'2) is repeated, for example, 5 times or more, more preferably 10 times. In addition, it is preferable to remove 85% or more of the remaining sodium by one cleaning step by adjusting the addition amount of water and an organic solvent used in the cleaning step, and more preferably 90% or more. Thereby, the concentration of the alkali metal in the copolymer 1 or the copolymer 2 after ring opening can be sufficiently reduced. In addition, the washing step (treatment S3 ) is preferably repeated so that the alkali metal concentration in the copolymer 1 or the copolymer 2 after ring-opening becomes 10 ppm or less, preferably 5 ppm or less.

In this embodiment, a negative photosensitive resin composition can contain the said polymer, a photosensitizer, and a crosslinking agent. Additives, such as a solvent, an adhesion improving agent, and a surfactant, can also be contained.

The upper limit of the content of the polymer in the present embodiment is 80 parts by mass or less, preferably 75 parts by mass or less, and more preferably 70 parts by mass or less, relative to 100 parts by mass of the total solid content of the negative photosensitive resin composition. Moreover, the lower limit of content of a polymer is 5 mass parts or more with respect to 100 mass parts of total solids of a negative photosensitive resin composition, Preferably it is 10 mass parts or more, More preferably, it is 20 mass parts or less. An appropriate crosslinked structure can be formed by exposing the negative photosensitive resin composition to the content of the polymer within the range of the above-mentioned upper limit and lower limit.

(Photosensitizer) In this embodiment, a photo-radical polymerization initiator can be used as a photosensitizer. As a photoradical polymerization initiator, an alkylphenone type initiator, an oxime ester type initiator, an acylphosphine oxide type initiator, etc. are mentioned specifically,. As a photoradical polymerization initiator, one of the above-mentioned specific examples can be used, or two or more of them can be used in combination. Among these, it is preferable to use an oxime ester type photo-radical polymerization initiator. Thereby, the photosensitizer can be radicalized with a low exposure amount, and the sensitivity can be improved.

Specific examples of the photoradical polymerization initiator include 1-hydroxycyclohexylphenone, 2,2-dimethoxy-1,2-diphenethan-1-one, 2-methyl-1- [4-(Methylthio)phenyl]-2-morpholin-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyl Ethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide, 1, 2-Octanedione, 1-[4-(phenylthio)-2-(o-benzyl oxime)]ethanone, 1-[9-ethyl-6-(2-methylbenzyl oxime) )-9H-carbazol-3-yl]-1-(o-acetyloxime) and so on. Among these, one type or two or more types may be used.

The upper limit of the content of the photosensitizer in the present embodiment may be 1 part by mass or more, preferably 1.5 parts by mass or more, and more preferably 2 parts by mass or more, relative to 100 parts by mass of the polymer. Thereby, in a negative photosensitive resin composition, the reaction rate by exposure can be improved. Therefore, the sensitivity can be improved. Moreover, the lower limit of the content of the photosensitizer is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and more preferably 10 parts by mass or less. Thereby, in the negative photosensitive resin composition, appropriate reactivity to the polymer can be expressed.

(Crosslinking agent) In the present embodiment, a known crosslinking agent can be used as the crosslinking agent. As a crosslinking agent, it is preferable to use, for example, an acrylic crosslinking agent containing a (meth)acrylic group. The acrylic crosslinking agent is, for example, a polyfunctional acrylic compound. Here, the polyfunctional acrylic compound refers to a compound having two or more (meth)acrylic groups. In addition, in this embodiment, a (meth)acrylic group means an acrylic group or a methacrylic group, that is, a methacrylic group. in addition. Acrylic groups contain acrylate groups. In addition, the methacrylate group includes a methacrylate group, that is, a methacrylate group. Here, as the combination of the crosslinking agent and the terminal unsaturated carbon double bond of the copolymer, for example, the crosslinking agent is an acrylic crosslinking agent, and the functional group having the terminal unsaturated carbon double bond of the copolymer contains the above-mentioned general formula The structure represented by (E1) or general formula (E2) is ideal. Thereby, the reactivity of the radical chain reaction of the crosslinking agent and the copolymer can be kept at the same level. Therefore, a preferable cross-linked structure can be formed.

Specific polyfunctional acrylic compounds include trimethylolpropane tri(meth)acrylate, trifunctional (meth)acrylates such as neotaerythritol tri(meth)acrylate, neotaerythritol tetra(meth)acrylate, etc. Tetrafunctional (meth)acrylates such as meth)acrylates, di(trimethylol)propane tetra(meth)acrylates, and hexafunctional (meth)acrylates such as dipeotaerythritol hexa(meth)acrylates Acrylate. One or more of these can be used. In addition, in this embodiment, a (meth)acrylate group means an acrylate group or a methacrylate group.

In the present embodiment, the lower limit of the content of the crosslinking agent may be 20 parts by mass or more, preferably 25 parts by mass or more, and more preferably 30 parts by mass or more, relative to 100 parts by mass of the polymer. Thereby, in addition to the crosslinked structure derived from the terminal unsaturated carbon double bond of the norbornene-type structural unit, a crosslinked structure can be formed. Therefore, the improvement of heat resistance, the improvement of solvent resistance, and the improvement of the residual film rate after image development can be aimed at. In addition, the upper limit of the content of the crosslinking agent may be 80 parts by mass or less, preferably 75 parts by mass or less, and more preferably 70 parts by mass or less, relative to 100 parts by mass of the polymer. Thereby, the crosslinking agent can be prevented from contributing excessively to the crosslinked structure, and the mobility of the norbornene-type structural unit can be appropriately suppressed. Therefore, the improvement of heat resistance, the improvement of solvent resistance, and the improvement of the residual film rate after image development can be aimed at.

(Solvent) The negative photosensitive resin composition described in this embodiment can be used as a varnish by dissolving each of the above-mentioned components in a solvent. Examples of such a solvent include N-methyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylacetamide, dimethylsulfoxide, diethylene glycol dimethyl ether, Diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl lactate, ethyl lactate, butyl lactate, methyl-1 , 3-Butanediol acetate, 1,3-butanediol-3-monomethyl ether, methyl pyruvate, ethyl pyruvate and methyl-3-methoxypropionate, etc. In addition, from the viewpoint of remarkably suppressing the occurrence of cracks in the resin film, among these compounds, a compound selected from the group consisting of γ-butyrolactone, dimethylsulfoxide, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether is used. , Diethylene glycol dibutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, and propylene glycol monomethyl ether acetate.

(Other Additives) In the present embodiment, the negative photosensitive resin composition may contain additives such as an adhesion improver, a surfactant, an antioxidant, a filler, a sensitizer, a silane coupling agent, and a terminal sealant as necessary.

The resin film of this embodiment is formed from the hardened|cured material of a negative photosensitive resin composition.

The resin film of this embodiment is formed from the above-mentioned negative photosensitive resin composition, and can be formed of these dry films or cured films. The negative photosensitive resin composition of the present embodiment is used to form resin films such as resists and permanent films. Such use is preferable from the viewpoint of heat resistance. In addition, the above-mentioned resist is composed of a resin film which is coated with a negative photosensitive resin composition by, for example, spin coating, roll coating, flow coating, dip coating, spray coating, blade coating, and the like, and removes the solvent. and obtained. The said permanent film consists of a cured film obtained by exposing and developing the said resin film, after forming a pattern into a desired shape, and making it harden by heat processing etc.. The permanent film can be used for, for example, a protective film, an interlayer film, a dam material, or the like.

The electronic device of the present embodiment uses the above-mentioned resin film.

The electronic device 100 of the present embodiment can include the above-described resin film. The electronic device 100 shown in FIG. 1 is, for example, a semiconductor wafer. At this time, for example, the electronic device 100 is mounted on the wiring board via the bumps 52 to obtain a semiconductor package. The electronic device 100 includes a semiconductor substrate provided with semiconductor elements such as transistors, and a multilayer wiring layer (not shown) provided on the semiconductor substrate. The interlayer insulating film 30 and the uppermost wiring 34 provided on the interlayer insulating film 30 are provided on the uppermost layer of the multilayer wiring layers. The uppermost layer wiring 34 is made of, for example, Al. In addition, a passivation film 32 is provided on the interlayer insulating film 30 and on the uppermost wiring 34 . A portion of the passivation film 32 is provided with an opening exposing the uppermost wiring 34 .

The rewiring layer 40 is provided on the passivation film 32 . The rewiring layer 40 has an insulating layer 42 provided on the passivation film 32 , a rewiring 46 provided on the insulating layer 42 , and an insulating layer 44 provided on the insulating layer 42 and the rewiring 46 . The insulating layer 42 is formed with an opening to be connected to the uppermost layer wiring 34 . The rewiring 46 is formed on the insulating layer 42 and disposed in the opening of the insulating layer 42 , and is connected to the uppermost wiring 34 . The insulating layer 44 is provided with an opening to be connected to the rewiring 46 . In the present embodiment, one or more of the passivation film 32 , the insulating layer 42 , and the insulating layer 44 can be constituted by, for example, a resin film formed by curing the above-mentioned photosensitive resin composition. At this time, the passivation film 32, the insulating layer 42, or the insulating layer 44 is formed by exposing the coating film to ultraviolet rays, developing a pattern, and then heating and curing the coating film. resin material.

Bumps 52 are formed in the openings provided in the insulating layer 44 through, for example, a UBM (Under Bump Metallurgy) layer 50 . The electronic device 100 is connected to a wiring board or the like via, for example, the bumps 52 .

In addition, this invention is not limited to the said embodiment, The deformation|transformation, improvement, etc. within the range which can achieve the objective of this invention are included in this invention. [Example]

Next, the Example of this invention is demonstrated. First, preparations were made as follows for each material used in the examples.

(Synthesis Example 1) A copolymer was prepared by using 5-norbornene-2-carboxylic acid and N-cyclohexylmaleimide in an input molar ratio of 50/50, and by adding methyl alcohol to the copolymer. Synthesis Example 1 was obtained by synthesizing a polymer of a copolymer based on glycidyl acrylate. A detailed description will be given below. In a reaction vessel of appropriate size equipped with a stirrer and a cooling pipe, weigh 5-norbornene-2-carboxylic acid (NC, manufactured by Honshu Chemical Industry Co., Ltd., 87.7 g, 0.630 mol) and 2,2' -Azobis(2-methylpropionic acid) dimethyl ester (V-601, manufactured by Wako Pure Chemical Industries, Ltd., 14.5 g, 63 mmol) and dissolved in methyl ethyl ketone (MEK, 58.0 g), thereby A solution was prepared. The dissolved liquid was purged with nitrogen gas for 10 minutes to remove oxygen, and then reacted at 70° C. for 6 hours while stirring. During the 6-hour reaction, a mixture of N-cyclohexylmaleimide (CMI, manufactured by NIPPON SHOKUBAI CO., LTD., 112.9 g, 0.630 mol) and MEK 127.5 g was continuously added to the reaction vessel over 6 hours. liquid. After the addition of the mixed solution of CMI was completed, the reaction was further carried out at 70° C. for 3 hours. After adding 266.7 g of MEK to the reaction liquid and diluting, it was added dropwise to a large amount of methanol/water mixed liquid (weight ratio 8/2) to precipitate a solid. The filtered solid was dried in a vacuum dryer at 50°C for 16 hours to obtain a polymer as a copolymer of 5-norbornene-2-carboxylic acid and N-cyclohexylmaleimide. The yield was 128.1 g, the Mw was 4,700, and the Mw/Mn was 1.63. In an appropriately sized reaction vessel equipped with a stirrer and a cooling pipe, the polymer (60.0 g) of the copolymer of the above-mentioned 5-norbornene-2-carboxylic acid and N-cyclohexylmaleimide was weighed, and Dissolved in PGMEA (140.0 g). Further, glycidyl methacrylate (GMA, manufactured by Tokyo Chemical Industry Co., Ltd., 20.7 g, 0.146 mol) and triethylamine (1.8 g) were added, and the mixture was heated at 80° C. for 5 hours. After adding formic acid to the reaction liquid and performing acid treatment, it was added dropwise to a large amount of methanol/water mixed liquid (weight ratio 8/2), and the polymer of Synthesis Example 1 was precipitated. The filtered solid was dried in a vacuum dryer at 40°C for 40 hours to obtain a polymer of Synthesis Example 1. The yield was 50.5 g, the Mw was 5,500, and the Mw/Mn was 1.65.

The obtained polymer of Synthesis Example 1 was dissolved in heavy DMSO, and 1H-NMR measurement was carried out with a nuclear magnetic resonance apparatus manufactured by JEOL Ltd. According to the spectrum obtained by 1H-NMR measurement, the signal derived from the methacryloyl group to which GMA was added was confirmed in δ 5.68 and δ 6.07, and the signal derived from the carboxyl group in the polymer was confirmed in δ 12.13 the signal. In addition, it was confirmed that the mol ratio of the carboxyl group and the methacryloyl group was 1:0.3 from the integral ratio of the respective signals. Thereby, it was confirmed that the carboxyl groups in some structural units derived from 5-norbornene-2-carboxylic acid were substituted with glycidyl methacrylate. Therefore, it was confirmed that a copolymer having each structural unit represented by the following formula (9) was obtained in Synthesis Example 1.

(Synthesis Example 2) A copolymer was prepared by using 5-norbornene-2-carboxylic acid, maleimide and N-cyclohexylmaleimide in a molar ratio of 50/15/35, and by The polymer of the copolymer was synthesized by adding glycidyl methacrylate to this copolymer, and it was set as Synthesis Example 2. A detailed description will be given below. In an appropriately sized reaction vessel equipped with a stirrer and a cooling pipe, weigh 5-norbornene-2-carboxylic acid (NC, manufactured by Honshu Chemical Industry Co., Ltd., 70.8 g, 0.512 mol), N-cyclohexyl Maleimide (CMI, manufactured by NIPPON SHOKUBAI CO., LTD., 14.23 g, 0.079 mol) and 2,2'-azobis(2-methylpropionic acid) dimethyl ester (V-601, Wako Pure Chemical Industries, Ltd. product, 11.8 g, 51 mmol) and dissolved in methyl ethyl ketone (MEK, 47.2 g) to prepare a solution. The dissolved liquid was purged with nitrogen gas for 10 minutes to remove oxygen, and then reacted at 70° C. for 6 hours while stirring. During the 6-hour reaction, a mixed solution of maleimide (14.9 g, 0.154 mol), CMI (50.1 g, 0.279 mol) and MEK 91.0 g was continuously added to the reaction vessel over 6 hours. After the addition of the solution was completed, it was further reacted at 70°C for 3 hours. After adding 200 g of MEK to the reaction solution and diluting it, it was added dropwise to a large amount of methanol/water mixed solution (weight ratio 5/5) to precipitate a solid. The filtered solid was dried in a vacuum dryer at 50°C for 64 hours to obtain a copolymer of 5-norbornene-2-carboxylic acid, maleimide and N-cyclohexylmaleimide polymer. The yield was 124.3 g, the Mw was 4,500, and the Mw/Mn was 1.75. In an appropriately sized reaction vessel equipped with a stirrer and a cooling pipe, weigh the polymer as a copolymer of the above-mentioned 5-norbornene-2-carboxylic acid, maleimide and N-cyclohexylmaleimide (50.0 g) and dissolved in PGMEA (100.0 g). Further, glycidyl methacrylate (GMA, manufactured by Tokyo Chemical Industry Co., Ltd., 24.3 g, 0.171 mol) and triethylamine (1.5 g) were added, and the mixture was heated at 90° C. for 4 hours. After adding formic acid to the reaction liquid and performing acid treatment, it was added dropwise to a large amount of methanol/water mixed liquid (weight ratio 5/5), and the polymer of Synthesis Example 2 was precipitated. The filtered solid was dried in a vacuum dryer at 40°C for 40 hours to obtain a polymer of Synthesis Example 2. The yield was 31.2 g, the Mw was 4,900, and the Mw/Mn was 1.72.

The obtained polymer of Synthesis Example 2 was dissolved in heavy DMSO, and 1H-NMR measurement was carried out with a nuclear magnetic resonance apparatus manufactured by JEOL Ltd. In the same manner as in Synthesis Example 1, a peak derived from a carboxyl group and a peak derived from a structure derived from a methacryloyl group were confirmed. Thereby, it was confirmed that the carboxyl groups in some structural units derived from 5-norbornene-2-carboxylic acid were substituted with glycidyl methacrylate. Therefore, it was confirmed that a copolymer having each structural unit represented by the following formula (10) was obtained in Synthesis Example 2.

(Synthesis Example 3) A copolymer was prepared using 2-norbornene and maleic anhydride at a molar ratio of 50/50, and the structural unit derived from maleic anhydride was ring-opened by sodium acetate, and Glycidyl methacrylate was added to synthesize a polymer of the copolymer, which was used as Synthesis Example 3. A detailed description will be given below. In an appropriately sized reaction vessel equipped with a stirrer and a cooling pipe, maleic anhydride (manufactured by NIPPON SHOKUBAI CO., LTD., 122.4 g, 1.25 mol), 2-norbornene (75 wt% toluene solution, Maruzen Petrochemical Co., Ltd.) were weighed. ., Ltd., 156.8 g, 1.25 mol) and 2,2'-azobis(2-methylpropionic acid) dimethyl ester (V-601, manufactured by Wako Pure Chemical Industries, Ltd., 11.5 g, 50 mmol) ) and dissolved in methyl ethyl ketone (MEK, 150.8 g) and toluene (38.5 g) to prepare a solution. The dissolved liquid was purged with nitrogen gas for 10 minutes to remove oxygen, and then heated to 60° C. with stirring. After 16 hours MEK (320 g) was added to dilute and cool. The reaction mixture was added dropwise to a large amount of methanol to precipitate a solid, which was filtered with a suction filter, and then washed with methanol, and the solid was collected by filtration. The obtained solid was vacuum-dried at 70°C to obtain a copolymer of 2-norbornene and maleic anhydride. The yield was 208.1 g, the weight average molecular weight (Mw) was 11,100, and the degree of dispersion (Mw/Mn) was 2.25. In an appropriately sized reaction vessel equipped with a stirrer and a cooling pipe, the above-mentioned copolymer of 2-norbornene and maleic anhydride (10.0 g) was weighed and dissolved in MEK (30.0 g). Further, 2-hydroxyethyl methacrylate (manufactured by HEMA, NIPPON SHOKUBAI CO., LTD., 8.5 g, 65 mmol) and sodium acetate (1.0 g) were added, and the mixture was heated at 70° C. for 8 hours. To this reaction liquid, glycidyl methacrylate (GMA, 1.5 g, 10 mmol) was added, and the mixture was further stirred at 70° C. for 16 hours. After adding formic acid to the reaction liquid for acid treatment, it was added dropwise to a large amount of pure water to precipitate a polymer. The filtered solid was dried in a vacuum dryer at 40°C for 16 hours to obtain a polymer of Synthesis Example 3. The yield was 11.5 g, the Mw was 14,100, and the Mw/Mn was 2.30. In Synthesis Example 3, a copolymer having each structural unit represented by the following formula (13) was obtained.

(Acid value) For each synthesis example, the acid value of the obtained polymer was calculated as follows. About 0.2 g of the synthesized polymer was weighed and dissolved in 50 mL of a solution of THF/methanol=1/1 (v/v). The obtained solution was potentiometrically titrated with a 0.1 M sodium methoxide/methanol solution. In potentiometric titration, the acid value of the polymer was evaluated by the amount of the reagent added up to the inflection point of the potential generated in the electrode.

(Alkali dissolution rate) For each synthesis example, the alkali dissolution rate of the obtained polymer was measured as follows. The polymer was dissolved in PGMEA to prepare a solution with a solid content concentration of 25%. The polymer solution was spin-coated on a silicon wafer and soft-baked at 100° C. for 120 seconds to form a polymer film having a thickness H of about 2.0 μm. The silicon wafer on which the polymer film was formed was immersed in a 2.38%, 23° C. tetramethylammonium hydroxide aqueous solution, and the time T until the polymer film disappeared visually was measured. Based on H and T, the alkali dissolution rate was calculated by the following formula. (Alkali dissolution rate) [Angstrom/sec]=(film thickness H)/(time T until polymer film disappears)

Table 1 below shows the results of evaluation of the acid value and the alkali dissolution rate for the polymers of each synthesis example.

[Table 1]

(Photosensitizer) Photosensitizer 1: A photo-radical polymerization initiator (Irgacure OXE02 manufactured by BASF Corporation) represented by the following formula (11) was used.

(Crosslinking agent) Crosslinking agent 1: An acrylic crosslinking agent represented by the following formula (12) (DPHA manufactured by Daicel-Cytec Company, Ltd.) was used.

(Adhesion Improver) Adhesion Improver 1: 3-glycidoxypropyltrimethoxysilane (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.)

(Surfactant) Surfactant 1: Megaface F-556 (manufactured by DIC Corporation)

Next, the negative photosensitive resin composition produced in the Example of this invention is demonstrated.

(Preparation of Negative Photosensitive Resin Compositions of Example 1, Example 2, and Comparative Example 1) For each Example and each Comparative Example, the compounding amounts shown in Table 2 were prepared in Synthesis Examples 1 to 3 The 20% PGMEA solution of the polymer, photosensitizer, crosslinking agent, adhesion improving agent and surfactant were dissolved in an appropriate amount of PGMEA and stirred. After stirring, it filtered through a 0.2 μm filter to prepare a negative resin composition. In addition, when preparing the negative photosensitive resin composition of each Example and each comparative example, PGMEA was adjusted so that content of a resin component (the sum total of a phenol resin and a polymer) might become 30%.

(Temperature at which weight is reduced by 5%) The temperature at which the weight is reduced by 5% in the heating process after curing was evaluated as follows using the obtained negative photosensitive resin composition for each Example and each comparative example. First, after applying the negative photosensitive resin composition to a 6-inch wafer, the solvent was removed by heat treatment at 80° C. for 90 seconds. Next, the negative photosensitive resin composition is heat-treated in an oven to harden the photosensitive resin composition. This heat treatment was performed by replacing the inside of the oven on which the wafers were placed with nitrogen gas at 30°C for 30 minutes, heating up to the curing temperature (200°C) at a heating rate of 5°C/min, The hardening temperature (200°C) was maintained for 30 minutes. After the above-mentioned heat treatment, the temperature in the oven was lowered to 70° C. or lower at a cooling rate of 5° C./min, and the above-mentioned wafer was taken out. Next, the cured film of the photosensitive resin composition was peeled off from the said wafer using hydrofluoric acid, and it dried on the conditions of 60 degreeC and 10 hours. In this way, a cured film cured at a curing temperature of 200° C. was obtained for each example and each comparative example. Next, the temperature (°C) at which the weight of the above-mentioned sample was reduced by 5% was measured. The measurement is performed on a sample obtained by weighing 10 mg of the cured film, using a thermogravimetric/differential calorimetry device (TG/DTA), at an initial temperature of 30°C, a measurement temperature range of 30 to 500°C, and a heating rate of 5°C/min. conditions. The temperature at the point where the weight of the weighed sample was reduced by 5% was taken as the temperature at which the weight was reduced by 5%.

(Remaining film rate after hardening) About each Example and each comparative example, the evaluation of the residual film rate after hardening was performed as follows using the obtained negative photosensitive resin composition. The obtained negative photosensitive resin composition was spin-coated on a 4-inch silicon wafer treated with HMDS (Hexamethyldisilazane), and baked at 110°C for 100 seconds on a hot plate After that, a thin film A with a thickness of about 3.0 μm was obtained. A g+h+i ray mask alignment exposure machine (PLA-501F) manufactured by Canon Inc. was used, using a mask with a 10 μm line-to-space width of 1:1, and a pattern size of 10 μm line-to-space The film A was exposed to an optimum exposure amount (50 mJ/cm ² ) with a width of 1:1, and developed with a 2.38 mass % aqueous tetramethylammonium hydroxide solution at 23° C. for 90 seconds, thereby obtaining a line Film B with a 1:1 line & space pattern with space width. From the film thickness of the thin film A and the thin film B obtained by the above-mentioned method, the residual film ratio was calculated by the following formula. Residual film ratio after curing (%)={(film thickness of film B (μm))/(film thickness of film A (μm))}×100

(Solvent resistance) The solvent resistance evaluation was performed as follows using the obtained negative photosensitive resin composition about each Example and each comparative example. The obtained negative photosensitive resin composition was spin-coated on a 1737 glass substrate made by Corning Incorporated with a size of 100 mm in length and 100 mm in width, and after baking at 110° C. for 100 seconds on a hot plate, a thickness of about 3.0 μm was obtained. The glass substrate with film. The glass substrate with the thin film was immersed in N-methylpyrrolidone (KANTO CHEMICAL CO., INC.) for 10 minutes at room temperature (25° C.), and then washed with pure water. The film thickness change rate defined by the following formula was calculated. Film thickness change rate (%)=[{(film thickness after solvent immersion)-(film thickness before solvent immersion)}/(film thickness before solvent immersion)]×100

(Sensitivity) For each Example and each comparative example, the sensitivity evaluation was performed as follows using the obtained negative photosensitive resin composition. The obtained negative photosensitive resin composition was spin-coated on a 4-inch silicon wafer treated with HMDS (Hexamethyldisilazane), and baked at 90°C for 120 seconds with a hot plate After that, a thin film with a thickness of about 3.0 μm was obtained. The film and the film were exposed by a g+h+i ray mask alignment exposure machine (PLA-501F) manufactured by Canon Inc. using a mask with a line-to-space width of 10 μm and a width of 1:1. Next, after baking on a hot plate at 110° C. for 120 seconds, a resist pattern was formed by developing a 2.38 mass % tetramethylammonium hydroxide aqueous solution at 23° C. for 60 seconds, and the resist pattern was 10 μm in size. Line width: The exposure amount (mJ/cm ² ) when the pitch width = 1:1 was used as the sensitivity.

[Table 2]

As shown in Table 1, it was confirmed that Synthesis Example 1 and Synthesis Example 2 are copolymers in which appropriate acid value and alkali dissolution rate are maintained. In addition, as shown in Table 2, it was confirmed that the negative photosensitive resin composition of Example 1 had better heat resistance, residual film ratio after curing, and solvent resistance than the negative photosensitive resin composition of Comparative Example 1. improve. Furthermore, compared with the negative photosensitive resin composition of Comparative Example 1, the negative photosensitive resin composition of Example 2 was confirmed to have improved heat resistance, residual film rate after curing, and solvent resistance, and further maintained sensitivity.

The present application claims priority based on Japanese Patent Application No. 2017-002022 for which it applied on January 10, 2017, and the entire contents of the disclosure are incorporated herein by reference.

30‧‧‧Interlayer insulating film 32‧‧‧Passivation film 34‧‧‧Topmost wiring 40‧‧‧Rewiring layer 42‧‧‧Insulating layer 44‧‧‧Insulating layer 46‧‧‧Rewiring 50‧‧‧Protrusion Under Bump Metal Layer 52‧‧‧Bumps 100‧‧‧Electronic Device

The above-mentioned objects and other objects, features, and advantages will become more apparent from the preferred embodiments described below and the following drawings that accompany them.

FIG. 1 is a cross-sectional view showing an example of an electronic device according to the present embodiment.

30‧‧‧Interlayer insulating film

32‧‧‧Passivation film

34‧‧‧Top layer wiring

40‧‧‧Redistribution layer

42‧‧‧Insulation

44‧‧‧Insulation

46‧‧‧Rewiring

50‧‧‧Under bump metal layer

52‧‧‧Bumps

100‧‧‧Electronic Devices

Claims (13)

A negative photosensitive resin composition, comprising: a polymer of a copolymer represented by the following formula (1); a crosslinking agent; and a photosensitizer,

In formula (1), l and m represent the molar content in the polymer, l+m=1, and the numerical range of l is 0.1

l

0.9, the numerical range of m is 0.1

m

0.9, A includes a structural unit represented by the following formula (A1) and a structural unit represented by the following formula (A2), and B includes the following formula (B1), the following formula (B2), the following formula (B3), At least one or more of the structural units represented by the following formula (B4), the following formula (B5) or the following formula (B6),

In formula (A1), R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen or an organic group having 1 to 30 carbon atoms, and R ₁ , R ₂ , R ₃ and R ₄ include at least one terminal unsaturated carbon double bond, n is 0, 1 or 2,

In formula (A2), R ₅ , R ₆ and R ₇ are each independently hydrogen or an organic group having 1 to 30 carbon atoms, and n is 0, 1 or 2,

In formula (B1), R ₈ is independently an organic group having 1 to 30 carbon atoms,

In formula (B2), R ₉ and R ₁₀ are each independently an organic group having 1 to 30 carbon atoms,

In formula (B6), R ₁₁ is independently an organic group having 1 to 30 carbon atoms. The negative photosensitive resin composition of claim 1, wherein the structural unit represented by the B of the copolymer comprises the structural unit represented by the above formula (B6). The negative photosensitive resin composition of claim 1, wherein the structural unit represented by the B of the copolymer comprises the structural unit represented by the above formula (B6) and the structural unit represented by the above formula (B5). The negative photosensitive resin composition of claim 1, wherein in the structural unit represented by the above formula (A1) of the copolymer, at least one of R ₁ , R ₂ , R ₃ and R ₄ is used as a terminal An unsaturated carbon double bond and a structural unit represented by the following general formula (E1),

In formula (E1), R _e is independently hydrogen or an organic group having 1 to 10 carbon atoms. The negative photosensitive resin composition of claim 1, wherein the crosslinking agent is an acrylic crosslinking agent containing a (meth)acrylic group. The negative photosensitive resin composition of claim 1, wherein the content of the crosslinking agent is 20 parts by mass or more and 80 parts by mass or less with respect to 100 parts by mass of the polymer. The negative photosensitive resin composition of claim 1, wherein the content of the polymer is 5 parts by mass to 80 parts by mass relative to 100 parts by mass of the total solid content of the negative photosensitive resin composition . The negative photosensitive resin composition of claim 1, wherein the content of the structural unit represented by the above formula (A1) in the copolymer is 0.1 mol or more relative to 1 mol of the structural unit represented by the above formula (A2). 3.0mol or less. The negative photosensitive resin composition of claim 1, wherein the photosensitizer is a photo-radical polymerization initiator. The negative photosensitive resin composition of claim 1, wherein the polymer has a weight average molecular weight of 1,500 or more and 30,000 or less. The negative photosensitive resin composition of claim 1, wherein the dispersity of the polymer is 1.0 or more and 2.5 or less. A resin film formed from a hardened product of the negative photosensitive resin composition according to any one of claims 1 to 11. An electronic device using the resin film as claimed in claim 12.

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