JP2013083958A - Photosensitive resin composition, and cured product and semiconductor element using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition which can form a fine pattern with a relatively low quality of exposure, does not require conventional thermal curing at a high temperature, and can obtain a cured product having sufficiently small tensile modulus of elasticity and excellent adhesiveness from and to an inorganic surface protective film and a metal wire material.SOLUTION: The photosensitive resin composition contains: (I) a bismaleimide compound having a cyclic imide bond and a bivalent hydrocarbon group (a) derived from a dimer acid; (II) a photopolymerization initiator; and (III) a silicon compound having four or more alkoxy groups bonded to silicon atoms.

Description

  The present invention relates to a photosensitive resin composition, a cured product using the same, and a semiconductor element. The photosensitive resin composition of the present invention can be applied to protective films for semiconductor elements, interlayer insulating films, insulating films for rewiring layers, and the like.

  Conventionally, polyimide precursors and polybenzoxazole precursors having excellent heat resistance, electrical characteristics, and mechanical characteristics have been used for protective films for semiconductor elements, interlayer insulating films formed on semiconductor surface layers, and insulating films for redistribution layers. The photosensitive resin composition containing is used. Examples of the photosensitive resin composition containing the polyimide precursor include polyamic acid, a compound having a polymerizable unsaturated bond, and a photopolymerization initiator described in JP-A No. 54-109828 (Patent Document 1). The resin composition to contain is described, and the resin composition containing a polyamic acid ester composition and a photoinitiator is described in Unexamined-Japanese-Patent No. 2008-83468 (patent document 2). The photosensitive polyimide precursor obtained in such a resin composition is a negative photosensitive material in which a pattern is obtained by photocrosslinking of unsaturated bonds with a photopolymerization initiator. Examples of the photosensitive resin composition containing the polybenzoxazole precursor include polybenzoxin disclosed in JP-A-56-27140 (Patent Document 3) and JP-A-11-237736 (Patent Document 4). A resin composition containing an oxazole precursor and a quinonediazide compound is described. Such a resin composition is a positive photosensitive material in which a pattern is obtained by dissolving a portion (exposed portion) irradiated with light by irradiation of light with quinonediazide to indenecarboxylic acid in an alkaline developer.

  Since the polyimide precursor and polybenzoxazole precursor as described in Patent Documents 1 to 4 need to undergo a dehydration ring-closing reaction in the curing reaction, heating is performed at least above 230 ° C. in order to cure. It is necessary. However, when the heating temperature is high in this way, the semiconductor element may be damaged, and the linear thermal expansion coefficient differs between the substrate such as a silicon wafer and the film made of the photosensitive resin composition. Further, there is a problem that residual stress is generated in the cured film due to a temperature difference until cooling to room temperature. Furthermore, in the photosensitive resin composition as described in Patent Documents 1 to 4, for the purpose of improving the heat resistance and mechanical properties, the polymer skeleton of the resin obtained by curing is an aromatic aromatic Since the skeleton is composed of a compound, the tensile elastic modulus after curing is increased, resulting in a problem that adhesion to an adherend is lowered and residual stress is further increased. Such residual stress causes warpage of the substrate such as a silicon wafer, and causes problems such as a decrease in bonding reliability with the interposer in flip chip mounting and the like, and a decrease in handling property of the substrate such as silicon wafer in the semiconductor manufacturing process. Cause it to be caused. In particular, in recent years, silicon wafers have been made thinner from the viewpoint of miniaturization and thinning of semiconductor elements, and the diameter of silicon wafers has been increased from the viewpoint of improving mass production (about 300 mm diameter at the mass production level. With the progress of a diameter of about 450 mm, such a problem related to residual stress becomes more serious.

  JP-A-2009-258433 (Patent Document 5) and JP-A-2009-175356 (Patent Document 6) disclose photosensitive resin compositions intended to reduce the curing temperature (curing temperature). Describes a resin composition containing a polybenzoxazole precursor. Furthermore, as another photosensitive resin composition, for example, it is obtained by a condensation reaction of an amine compound and a diamine derived from dimer acid and tetracarboxylic dianhydride in JP 2010-256532 A (Patent Document 7). A photosensitive resin composition containing a polyamic acid is described. JP-T-2006-526014 (Patent Document 8) describes a polymaleimide compound in which an amic acid structure is closed in advance and a maleimide group is introduced as a polymerizable functional group. A photosensitive resin composition containing an imide compound is described in US Patent Application Publication No. 2011/0049731 (Patent Document 9).

JP-A-54-109828 JP 2008-83468 A JP-A-56-27140 Japanese Patent Laid-Open No. 11-237736 JP 2009-258433 A JP 2009-175356 A JP 2010-256532 A JP 2006-526014 A US Patent Application Publication No. 2011/0049731

  Since polyimide precursors and polybenzoxazole precursors have large absorption at 436 nm and 365 nm, a reduction projection exposure machine (stepper; light source wavelength: 365 nm, 436 nm) that is used in the manufacturing process of semiconductor protective films and the like is used. When used, the present inventors have found that the light reaching the bottom decreases as the film thickness increases, making it difficult to form a pattern. In particular, the film thickness of a protective film for a semiconductor element or the like is generally 5 μm or less, but there are often portions where the film thickness is actually 10 μm or more due to unevenness due to wiring. The present inventors have found that sufficient patterning performance is not exhibited and the chip design is limited.

  Moreover, the polyamic acid described in Patent Document 7 has a polyamic acid structure obtained from an amine compound (dimeramine amine) derived from dimer acid and tetracarboxylic dianhydride, and has excellent flexibility. It is expected that a cured product can be obtained. However, since the polyamic acid described in Patent Document 7 does not have a photopolymerizable functional group, it is necessary to add a photopolymerizable compound to the resin composition. For example, it is generally used as a photopolymerizable compound. When a polyfunctional polymerizable compound having a plurality of polymerizable functional groups such as an acrylic compound is used together with the polyamic acid, there is a problem that a crosslinking reaction by photopolymerization proceeds and a tensile elastic modulus after curing is increased. The inventors have found. Furthermore, since the photosensitive resin composition described in Patent Document 7 needs to perform a dehydration ring-closing reaction of an amic acid structure in a curing reaction, heating at a high temperature exceeding 230 ° C. is necessary. The present inventors have found that there is a problem in that residual stress that causes warping of the substrate occurs.

Furthermore, since the polymaleimide compound described in Patent Document 8 is a soluble imide oligomer, the resin composition described in Patent Document 9 containing the compound can be cured at a relatively low temperature. However, when the resin composition described in Patent Document 9 is used, an inorganic surface protective film (passivation film) such as a SiN film or SiO ₂ film formed on a silicon wafer or chip, or a conductive metal wiring material ( The present inventors have found that there is a problem that the adhesiveness with a copper or the like is remarkably lowered and that a fine pattern is difficult to form. Further, as a method for improving the adhesion, a method for improving the efficiency of the crosslinking reaction by photopolymerization by increasing the exposure amount can be mentioned, but the polymaleimide compound described in Patent Document 8 is usually used as a photopolymerizable compound. The present inventors have found that a very large amount of exposure is required as compared with the acrylic compound and the like that are used, and this causes a problem of causing a decrease in productivity in the semiconductor manufacturing process. Furthermore, as a method of reducing the residual stress in the cured film or improving the patterning performance, there is a method of reducing the film thickness. When the film thickness is reduced, the original protective film or insulating film for semiconductor elements The present inventors have found that there is a problem in that the function as is lost.

  The present invention has been made in view of the above-mentioned problems of the prior art, can form a fine pattern with a relatively low exposure amount, does not require thermosetting at a high temperature as in the prior art, and is tensile. To provide a photosensitive resin composition having a sufficiently small elastic modulus and capable of obtaining a cured product excellent in adhesion to an inorganic surface protective film or a metal wiring material, and a cured product and a semiconductor element using the same. Objective.

  As a result of intensive studies to achieve the above object, the present inventors have used a specific bismaleimide compound, a photopolymerization initiator, and a specific silicon compound in combination in the photosensitive resin composition. It is possible to form a fine pattern with a relatively low exposure amount, and it does not require thermosetting and does not require thermosetting at a high temperature as in the past even when thermosetting is required. I found. Furthermore, the cured product obtained by using such a photosensitive resin composition has a sufficiently small tensile elastic modulus and excellent adhesion to an inorganic surface protective film or a metal wiring material, and the surface of the semiconductor element. It has been found that it can be particularly suitably used as a protective film, an interlayer insulating film, an insulating film of a rewiring layer, and the like, and the present invention has been completed.

  That is, the photosensitive resin composition of the present invention comprises (I) a bismaleimide compound having a cyclic imide bond and a divalent hydrocarbon group (a) derived from dimer acid, (II) a photopolymerization initiator, and ( III) It contains a silicon compound having 4 or more alkoxy groups bonded to a silicon atom.

  In the photosensitive resin composition of the present invention, the (I) bismaleimide compound is obtained by reacting a diamine (A) derived from dimer acid, tetracarboxylic dianhydride, and maleic anhydride. Diamine (A) derived from dimer acid, organic diamine (B) other than diamine (A) derived from dimer acid, tetracarboxylic dianhydride, maleic anhydride A bismaleimide compound obtained by reacting a product is preferable.

  Moreover, as the photosensitive resin composition of the present invention, the (I) bismaleimide compound is represented by the following general formula (1):

[In Formula (1), R ¹ represents a divalent hydrocarbon group (a) derived from dimer acid, and R ² represents a divalent other than the divalent hydrocarbon group (a) derived from dimer acid. R ³ represents a divalent organic group other than the divalent hydrocarbon group (a) derived from dimer acid and the divalent hydrocarbon group (a) derived from dimer acid. (B) represents any one selected from the group consisting of R ⁴ and R ^{5, which} may be the same or different, each represents a tetravalent organic group, and m is an integer of 1 to 30. , N is an integer of 0-30, and when m is 2 or more, a plurality of R ¹ and R ⁴ may be the same or different, and when n is 2 or more, a plurality of R ² and R 4 are present. ⁵ may be the same or different. ]
It is preferable that it is a bismaleimide compound represented by these.

  Furthermore, in the photosensitive resin composition of the present invention, the (II) photopolymerization initiator is preferably a compound having at least one kind of structure selected from the group consisting of an oxime structure and a thioxanthone structure. .

  Moreover, as a photosensitive resin composition of this invention, it is preferable that content of the said (III) silicon compound is 0.1-3 mass parts with respect to 100 mass parts of said (I) bismaleimide compounds. Furthermore, as the photosensitive resin composition of the present invention, the content of the (II) photopolymerization initiator is 0.1 to 15 parts by mass with respect to 100 parts by mass of the (I) bismaleimide compound. preferable.

Moreover, as the photosensitive resin composition of this invention, it is preferable that the residual film rate of the exposed part after exposure becomes 90% or more by exposure wavelength 365nm and exposure amount 300-2000mJ / cm < ² >, and after hardening The tensile modulus is preferably 2 GPa or less, and the curing temperature is preferably 60 to 230 ° C.

  Furthermore, the cured product of the present invention is obtained by photocuring or photothermal curing the photosensitive resin composition of the present invention. The semiconductor element of the present invention comprises the cured product of the present invention as at least one selected from the group consisting of a surface protective film, an interlayer insulating film, and an insulating film of a rewiring layer. is there.

  In addition, although the reason that the said objective is achieved by the photosensitive resin composition of this invention is not necessarily certain, the present inventors guess as follows. That is, since the conventional maleimide compound generally undergoes a dimerization reaction mainly in the photopolymerization reaction, the efficiency of the cross-linking reaction tends to be smaller than that of an acrylic compound that is another photopolymerizable compound. For this reason, the present inventors speculate that a very large amount of exposure is required to sufficiently form a crosslinked structure by photopolymerization. Conventionally, maleimide compounds have been mainly used as thermopolymerizable compounds because the photoreaction of the compound itself proceeds only at a wavelength of 310 nm or less, and it is difficult to cause chain polymerization by radicals. It was. On the other hand, since the specific bismaleimide compound according to the present invention has a flexible skeleton structure including a structure derived from dimer acid, such a bismaleimide compound and a photopolymerization initiator that generates radicals are specified. By combining with the silicon compound, maleimide groups are easily adjacent to each other and the efficiency of the crosslinking reaction is improved. Therefore, according to the photosensitive resin composition of the present invention, it is possible to form a fine pattern with a relatively low exposure amount, no need for thermosetting at a high temperature as in the prior art, and a sufficient tensile elastic modulus. The present inventors speculate that a cured product having a small size and excellent adhesion to an adherend can be obtained.

In addition, in a maleimide compound such as the polymaleimide compound described in Patent Document 8, the amidic acid structure is closed in advance, and there are almost no polar groups in the molecule, so that a SiN film, a SiO ₂ film, etc. The present inventors infer that the adhesion (adhesiveness) with a metal wiring material such as an inorganic surface protective film or copper is significantly reduced. In contrast, in the photosensitive resin composition of the present invention, a specific bismaleimide compound and a photopolymerization initiator include a specific silicon compound, that is, a silicon compound having four or more alkoxy groups bonded to silicon atoms. When used in combination, the silanol group produced by hydrolysis of an alkoxy group bonded to a silicon atom exerts adhesion (adhesion) to an inorganic surface protective film or a metal wiring material. The present inventors infer that a cured product having excellent adhesion to a metal wiring material can be obtained. Furthermore, when the silicon compound according to the present invention further has a reactive organic group such as an epoxy group or a (meth) acryl group, the cured product of the photosensitive resin composition of the present invention and an inorganic surface protective film or metal The inventors speculate that the adhesion to the wiring material is further improved.

  As described above, the cured product obtained from the photosensitive resin composition of the present invention includes a specific silicon compound in addition to being able to sufficiently adhere to the adherend due to sufficiently low tensile elastic modulus. Since the interaction with the inorganic surface protective film and the metal wiring material also occurs, the present inventors presume that the adhesion to the adherend, particularly the inorganic surface protective film and the metal wiring material is excellent.

  Further, in the photosensitive resin composition of the present invention, since the absorption at 365 nm is small, even if the film thickness is 10 μm or more, a reduction projection exposure apparatus that is normally used in the manufacturing process of a semiconductor protective film or the like The present inventors infer that it is possible to form a fine pattern by using this.

  According to the present invention, it is possible to form a fine pattern with a low exposure, does not require thermosetting at a high temperature as in the prior art, and has a sufficiently low tensile elastic modulus, an inorganic surface protective film and a metal wiring. It becomes possible to provide a photosensitive resin composition capable of obtaining a cured product having excellent adhesion to a material, a cured product using the same, and a semiconductor element.

  Further, according to the photosensitive resin composition of the present invention, thermosetting is not required, and even when thermosetting is performed as required, thermosetting at a relatively low temperature is possible, and tensile modulus Therefore, a sufficiently small cured product can be obtained, so that the residual stress generated in the cured film can be sufficiently reduced, and warping of a substrate such as a silicon wafer can be sufficiently suppressed. Furthermore, according to the photosensitive resin composition of the present invention, even with a film thickness of 10 μm or more, an aspect of a fine pattern (preferably an opening diameter (Via diameter)) by light irradiation of 310 to 436 nm (preferably 365 nm). A ratio of 0.3 or more, more preferably 0.5 or more). In the present invention, the aspect ratio of the opening diameter (Via diameter) is a value represented by the following formula: aspect ratio = (film thickness of cured film) / (opening diameter of through-hole formed in the cured film). It is.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof.

  The photosensitive resin composition of the present invention comprises (I) a bismaleimide compound, (II) a photopolymerization initiator, and (III) a silicon compound having four or more alkoxy groups bonded to silicon atoms. To do.

<(I) Bismaleimide Compound>
The (I) bismaleimide compound according to the present invention is a compound having two maleimide groups, and has a divalent hydrocarbon group (a) derived from dimer acid and a cyclic imide bond. Such (I) bismaleimide compound can be obtained by reacting diamine (A) derived from dimer acid, tetracarboxylic dianhydride, and maleic anhydride.

  The divalent hydrocarbon group (a) derived from the dimer acid refers to a divalent residue obtained by removing two carboxyl groups from the dicarboxylic acid contained in the dimer acid. In the present invention, the divalent hydrocarbon group (a) derived from such dimer acid is a diamine (A) obtained by substituting two carboxyl groups of dicarboxylic acid contained in dimer acid with amino groups. ) And a tetracarboxylic dianhydride and maleic anhydride, which will be described later, to form an imide bond, which can be introduced into the bismaleimide compound.

  In the present invention, the dimer acid is obtained by dimerizing unsaturated bonds of unsaturated carboxylic acids such as linoleic acid, oleic acid, and linolenic acid, and then distilled and purified. It mainly contains a dicarboxylic acid, and usually contains about 54% by mass of a tricarboxylic acid having 54 carbon atoms and about 5% by mass of a monocarboxylic acid. The diamine (A) derived from dimer acid according to the present invention (hereinafter sometimes referred to as dimer acid-derived diamine (A)) has two carboxyl groups of each dicarboxylic acid contained in the dimer acid as amino groups. A diamine obtained by substitution, usually a mixture. In the present invention, such a dimer acid-derived diamine (A) is, for example, [3,4-bis (1-aminoheptyl) 6-hexyl. Examples include diamines such as -5- (1-octenyl)] cyclohexane, and diamines saturated with unsaturated bonds by hydrogenation of these diamines.

  As the divalent hydrocarbon group (a) derived from the dimer acid according to the present invention introduced into the bismaleimide compound using such a dimer acid-derived diamine (A), the dimer acid-derived diamine (A It is preferably a residue obtained by removing two amino groups from). Moreover, when obtaining the bismaleimide compound based on this invention using the said dimer acid origin diamine (A), even if it uses individually by 1 type as said dimer acid origin diamine (A), two or more types from which a composition differs are used. You may use it in combination. Further, as such a dimer acid-derived diamine (A), for example, a commercially available product such as “PRIAMINE 1074” (manufactured by Croda Japan Co., Ltd.) may be used.

  In the present invention, the cyclic imide bond refers to a bond in which two imide bonds are linked in a cyclic manner. In the present invention, such a cyclic imide bond is formed by reacting a tetracarboxylic dianhydride with the dimer acid-derived diamine (A) and the organic diamine (B) described below to form an imide bond. It can be introduced into the compound.

  Examples of the tetracarboxylic dianhydride include pyromellitic dianhydride, 2,2 ′, 3,3′-, 2,3,3 ′, 4′- or 3,3 ′, 4,4 ′. -Benzophenone tetracarboxylic dianhydride, 2,3,6,7-, 1,2,4,5-, 1,4,5,8-, 1,2,6,7- or 1,2,5 , 6-Naphthalene-tetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 2 , 6- or 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7- (or 1,4,5,8-) tetrachloronaphthalene-1 , 4,5,8- (or 2,3,6,7-) tetracarboxylic dianhydride, 3,3 ', 4,4'-, 2,2', 3,3'- Is 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 3,3 ″, 4,4 ″-, 2,3,3 ″, 4 ″-or 2,2 ″ , 3,3 ″ -p-terphenyltetracarboxylic dianhydride, 2,2-bis (2,3- or 3,4-dicarboxyphenyl) -propane dianhydride, bis (2,3-di Carboxyphenyl) ether dianhydride, bis (2,3- or 3.4-dicarboxyphenyl) methane dianhydride, bis (2,3- or 3,4-dicarboxyphenyl) sulfone dianhydride, 1, 1-bis (2,3- or 3,4-dicarboxyphenyl) ethane dianhydride, 2,3,8,9-, 3,4,9,10-, 4,5,10,11- or 5 , 6,11,12-perylene-tetracarboxylic dianhydride, 1,2,7,8-, 1,2,6,7- 1,2,9,10-phenanthrene-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride Pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride, 4,4′-oxydiphthalic dianhydride. Among these, from the viewpoint that a photocurable resin composition excellent in light transmittance at 365 nm is obtained, and a cured product excellent in heat resistance is obtained, the tetracarboxylic dianhydride may be pyromellitic. An acid dianhydride is preferred. Moreover, when obtaining the bismaleimide compound based on this invention using these tetracarboxylic dianhydrides, even if it uses individually 1 type of these tetracarboxylic dianhydrides, it combines 2 or more types May be used.

  Furthermore, as the (I) bismaleimide compound according to the present invention, the dimer acid-derived diamine (A), the organic diamine (B) other than the dimer acid-derived diamine (A), the tetracarboxylic dianhydride, A bismaleimide compound obtained by reacting with the maleic anhydride may also be used. By copolymerizing an organic diamine (B) other than the dimer acid-derived diamine (A), the required physical properties can be controlled as required, such as further reducing the tensile modulus of the cured product obtained.

  The organic diamine (B) other than the dimer acid-derived diamine (A) (hereinafter sometimes simply referred to as organic diamine (B)) refers to a diamine other than the diamine contained in the dimer acid-derived diamine (A) in the present invention. Point to. Such an organic diamine (B) is not particularly limited, and examples thereof include aliphatic diamines such as 1,6-hexamethylenediamine; alicyclic diamines such as 1,4-diaminocyclohexane; 4,4′-diamino Diphenyl ether, 3,4'-diaminodiphenyl ether, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1 , 4-diaminobenzene, 1,3-diaminobenzene, 2,4-diaminotoluene, 4,4′-diaminodiphenylmethane and other aromatic diamines; 4,4′-diaminodiphenylsulfone; 3,3′-diaminodiphenylsulfone 4,4-diaminobenzophenone; 4,4-diaminodiphenyl sulfide; 2,2- The [4- (4-aminophenoxy) phenyl] propane. Among these, from the viewpoint of obtaining a cured product having a lower tensile elastic modulus, an aliphatic diamine having 6 to 12 carbon atoms such as 1,6-hexamethylenediamine; diaminocyclohexane such as 1,4-diaminocyclohexane. An aromatic diamine having an aliphatic structure having 1 to 4 carbon atoms in an aromatic skeleton such as 2,2-bis [4- (4-aminophenoxy) phenyl] propane is more preferable. Moreover, when obtaining the bismaleimide compound based on this invention using these organic diamine (B), even if it uses individually by 1 type in these organic diamine (B), it uses it in combination of 2 or more types. May be.

  A method of reacting the dimer acid-derived diamine (A), the tetracarboxylic dianhydride, and the maleic anhydride, or the dimer acid-derived diamine (A) and the organic diamine (B), The method for reacting the tetracarboxylic dianhydride and the maleic anhydride is not particularly limited, and a known method can be appropriately employed. For example, first, the dimer acid-derived diamine (A) And the tetracarboxylic dianhydride and, if necessary, the organic diamine (B), a solvent such as toluene, xylene, tetralin, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, or the like Polyamic acid was synthesized by stirring for 30 to 60 minutes at room temperature (about 23 ° C.) in a solvent such as a mixed solvent. Added in acid to synthesize a polyamic acid at both ends maleic acid was added with stirring for 30-60 minutes at room temperature (about 23 ° C.). To this polyamic acid, a solvent such as toluene that is azeotroped with water is further added, and the desired bismaleimide compound is obtained by refluxing at a temperature of 100 to 160 ° C. for 3 to 6 hours while removing water generated during imidization. Can be obtained. In such a method, a catalyst such as pyridine may be further added.

  The mixing ratio of the raw materials in the reaction is (total number of moles of all diamines and organic diamine (B) contained in the dimer acid-derived diamine (A)): (total number of moles of tetracarboxylic dianhydride + maleic anhydride It is preferable that 1/2 of the number of moles of the product is 1: 1. Moreover, when using the said organic diamine (B), the softness | flexibility derived from a dimer acid expresses and the viewpoint that it exists in the tendency for the hardened | cured material of a lower elasticity modulus to be obtained, (mol of organic diamine (B)) Number) / (number of moles of all diamines contained in the dimer acid-derived diamine (A)) is preferably 1 or less, and more preferably 0.4 or less. In addition, when using the said organic diamine (B), the amide acid unit which consists of dimer acid origin diamine (A) and tetracarboxylic dianhydride, and organic diamine (B) and tetracarboxylic dianhydride The polymerization form with the acid unit may be random polymerization or block polymerization.

  As the (I) bismaleimide compound thus obtained, the following general formula (1):

It is preferable that it is a bismaleimide compound represented by these. In the formula (1), R ¹ represents a divalent hydrocarbon group (a) derived from dimer acid, and R ² represents a divalent other than the divalent hydrocarbon group (a) derived from dimer acid. R ³ represents a divalent organic group other than the divalent hydrocarbon group (a) derived from dimer acid and the divalent hydrocarbon group (a) derived from dimer acid. Any one selected from the group consisting of (b) is shown, and R ⁴ and R ⁵ may be the same or different and each represents a tetravalent organic group.

  The divalent hydrocarbon group (a) derived from the dimer acid in the formula (1) is as described above. In the present invention, the divalent organic group (b) other than the divalent hydrocarbon group (a) derived from the dimer acid in the formula (1) refers to two amino acids from the organic diamine (B). This refers to a divalent residue excluding a group. However, in the same compound, the divalent hydrocarbon group (a) derived from the dimer acid and the divalent organic group (b) are not the same. Furthermore, the tetravalent organic group in the formula (1) refers to a tetravalent residue obtained by removing two groups represented by -CO-O-CO- from the tetracarboxylic dianhydride.

  In the formula (1), m is the number of repeating units containing the divalent hydrocarbon group (a) derived from the dimer acid (hereinafter sometimes referred to as dimer acid-derived structure), and an integer of 1 to 30 Indicates. When the value of m exceeds the above upper limit, the solubility in a solvent is lowered, and in particular, the solubility in a developer during development described later is lowered. Further, the value of m is particularly preferably 3 to 10 from the viewpoint that the solubility in a developer during development is suitable.

  In said Formula (1), n is the number of the repeating units (henceforth organic diamine origin structure depending on the case) containing the said bivalent organic group (b), and shows the integer of 0-30. When the value of n exceeds the above upper limit, the flexibility of the resulting cured product is deteriorated, resulting in a hard and brittle resin. Further, the value of n is particularly preferably 0 to 10 from the viewpoint that a cured product having a low elastic modulus tends to be obtained.

Further, when m in the formula (1) is 2 or more, R ¹ and R ⁴ may be the same or different, respectively, and when n in the formula (1) is 2 or more, R ² and R ⁵ may be the same or different. Furthermore, as the bismaleimide compound represented by the formula (1), the dimer acid-derived structure and the organic diamine-derived structure may be random or block.

  In the case of obtaining the bismaleimide compound according to the present invention from the dimer acid-derived diamine (A), the maleic anhydride, the tetracarboxylic dianhydride and, if necessary, the organic diamine (B), the reaction rate Is 100%, n and m are mixed moles of all diamines, organic diamine (B), maleic anhydride and tetracarboxylic dianhydride contained in the dimer acid-derived diamine (A). It can be expressed by a ratio. That is, (m + n): (m + n + 2) is (total number of moles of all diamines and organic diamine (B) contained in dimer acid-derived diamine (A)): (total moles of maleic anhydride and tetracarboxylic dianhydride) M: n is represented by (number of moles of all diamines contained in dimer acid-derived diamine (A)): (number of moles of organic diamine (B)), and 2: (m + n) is (Mole number of maleic anhydride): (Mole number of tetracarboxylic dianhydride).

  Furthermore, in the (I) bismaleimide compound according to the present invention, the sum (m + n) of m and n is 2 to 30 from the viewpoint that a cured product having a lower elastic modulus tends to be obtained. Is preferred. Further, the ratio of m to n (n / m) is 1 or less from the viewpoint that flexibility derived from dimer acid is expressed and a cured product having a lower elastic modulus tends to be obtained. Is preferable, and it is more preferable that it is 0.4 or less.

  As the (I) bismaleimide compound according to the present invention, a commercially available compound may be used as appropriate, for example, “BMI-3000” (manufactured by DESIGNER MOLECURES Inc.); dimer diamine, pyromellitic dianhydride and maleic acid. What was synthesize | combined from the anhydride; m + n can use 4-7) suitably. In addition, as the (I) bismaleimide compound according to the present invention, one kind may be used alone, or two or more kinds may be used in combination.

<(II) Photopolymerization initiator>
The (II) photopolymerization initiator according to the present invention is not particularly limited, and those conventionally used can be appropriately employed. For example, acetophenone, 2,2-dimethoxyacetophenone, p-dimethylaminoacetophenone, Michler's ketone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzyl dimethyl ketal, thioxatone, 2-chlorothioxazone, 2-methylthioxa 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2) -Methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2- Dimethylamino-1- (4-morpholinophenyl) -1-butanone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 1 , 2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], ethanone, 1- [9-ethyl-6- ( - methylbenzoyl) -9H- carbazol-3-yl] -, 1-(O-acetyl oxime), photopolymerization initiators such as 2,4-dimethyl thioxanthone, and the like. As such (II) photopolymerization initiator, one kind may be used alone, or two or more kinds may be used in combination.

  Among these, as the (II) photopolymerization initiator according to the present invention, a reduction projection exposure machine (stepper; light source wavelength: 365 nm, 436 nm) that is standardly used in the manufacturing process of a semiconductor protective film or the like is used. From the viewpoint that a fine pattern can be formed, it is preferable to use one that efficiently generates radicals at an exposure wavelength of 310 to 436 nm (more preferably 365 nm). Further, the maleimide group generally does not undergo homopolymerization with radicals, and a dimerization reaction of the bismaleimide compound proceeds mainly by reaction with radicals generated from the photopolymerization initiator to form a crosslinked structure. For this reason, the present inventors speculate that bismaleimide compounds are apparently less reactive than acrylic compounds generally used as photopolymerizable compounds. Therefore, from the viewpoint that radicals can be generated more efficiently and the reactivity at an exposure wavelength of 310 to 436 nm (more preferably 365 nm) is increased, the (II) photopolymerization initiator according to the present invention includes an oxime. More preferably, it is a compound having at least one structure selected from the group consisting of a structure and a thioxanthone structure.

  As such (II) photopolymerization initiator, for example, 1,2-octanedione having an oxime structure, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)] (manufactured by BASF Japan, “IRGACURE OXE-01”), ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime) (manufactured by BASF Japan, IRGACURE OXE-02 ") and 2,4-dimethylthioxanthone having a thioxanthone structure (manufactured by Nippon Kayaku Co., Ltd.," DETX-S "). Such a photopolymerization initiator having a high radical generating ability due to light tends to be too reactive to control the reaction when used for photopolymerization of ordinary acrylic compounds, etc. It can be used suitably.

<(III) silicon compound>
The (III) silicon compound according to the present invention has four or more alkoxy groups bonded to silicon atoms. In the present invention, by using such a (III) silicon compound in combination with the (I) bismaleimide compound and (II) photopolymerization initiator, an inorganic surface protective film such as a silicon nitride film or a silicon oxide film, or copper A cured product having excellent adhesion (adhesiveness) to a metal wiring material such as the above can be obtained, and a fine pattern can be formed even at a relatively low exposure amount.

  In the (III) silicon compound according to the present invention, when the alkoxy group bonded to the silicon atom is less than 4, it is difficult to form a fine pattern at a low exposure amount, and the inorganic surface protective film in the resulting cured product In addition, the adhesion to metal wiring materials is reduced. Moreover, as (III) silicon compound which concerns on this invention, it is preferable that the alkoxy group couple | bonded with the said silicon atom is 4-40 pieces, and it is more preferable that it is 6-30 pieces. When the number of alkoxy groups bonded to the silicon atom is less than the lower limit, the adhesiveness of the obtained cured product to the inorganic surface protective film or the metal wiring material tends to be lowered. On the other hand, when it exceeds the upper limit, the solubility in a solvent tends to be lowered, and there may be a problem that a residue remains at an opening at the time of development.

  In addition, as the (III) silicon compound according to the present invention, a methyl group, an ethyl group, an acryl group, a methacryl group, a methacryl group, a methacryl group, a methacryl group, a methacryl group, a methacryl group, a methacryl group, and a methacryl group can be used. It is preferable to further have an organic group such as a group, an amino group, a mercapto group, an epoxy group, or a 3,4-epoxycyclohexyl group. Moreover, when it has such an organic group, it is preferable that the average content per molecule is 2-30. When the content is less than the lower limit, further improvement in adhesion tends not to be expected. On the other hand, when the content exceeds the upper limit, synthesis tends to be difficult.

  As such (III) silicon compound, for example, a monovalent silyl group represented by the following general formula (2), in which an alkoxy group and an organic group are bonded to a silicon atom,

An alkoxy group having at least one silyl group selected from the group consisting of a divalent silyl group having an alkoxy group and an organic group bonded to a silicon atom, represented by the following general formula (3), bonded to the silicon atom is 4 Examples thereof include silicon compounds having more than one.

Moreover, as such a silicon compound, you may have further the bivalent silyl group which the organic group couple | bonded with the silicon atom represented by following General formula (4).

In the formulas (2) to (4), R ⁶ may be the same or different and each represents a monovalent organic group. Examples of the monovalent organic group include a methyl group, an ethyl group, an acrylic group, a methacryl group, an amino group, a mercapto group, an epoxy group, and a 3,4-epoxycyclohexyl group. Among these, a bismaleimide compound and From the viewpoint that the adhesiveness with the inorganic surface protective film or the metal wiring material tends to further improve in the cured product obtained by reaction or interaction, epoxy group, acrylic group, methacryl group, 3,4-epoxycyclohexyl. Group is more preferable, and an epoxy group and a 3,4-epoxycyclohexyl group are more preferable. In the formulas (2) to (4), R ⁷ may be the same or different and each represents a methyl group or an ethyl group. Furthermore, in said formula (2), p shows the integer of 0-2. In the present invention, an inorganic surface protective film or a metal in a cured product obtained by reacting or interacting with a silanol group generated by hydrolysis of an alkoxy group bonded to a silicon atom and the monovalent organic group with a bismaleimide compound. From the viewpoint of further improving the adhesiveness with the wiring material, the p is preferably an integer of 1 to 2.

Such silicon compounds are, for example, the trialkoxysilane compound having a monovalent organic group described as ^{R 6 (SiR 6 (OR 7} ) 3) , or dialkoxy silane compound _{^{(Si (R 6) 2 (}} OR 7 ₂ ) It can be obtained by condensing a compound obtained by hydrolyzing part or all of the alkoxy group of ₂ ). Moreover, the (III) silicon compound which concerns on this invention is a trialkoxysilane compound which has organic groups which have unsaturated bonds, such as a vinyl group and a (meth) acryl group, among the monovalent organic groups mentioned as said R < ⁶ >. The unsaturated bond of (SiR ⁶ (OR ⁷ ) ₃ ), dialkoxysilane compound (Si (R ⁶ ) ₂ (OR ⁷ ) ₂ ), monoalkoxysilane compound (Si (R ⁶ ) ₃ (OR ⁷ )) is a radical. It can also be obtained by polymerization.

  More specific examples of such (III) silicon compound include an alkoxysilane oligomer represented by the following general formula (5). In the present invention, from the viewpoint that the obtained cured product tends to improve the adhesion to the inorganic surface protective film and the metal wiring material, the (III) silicon compound is as such an alkoxysilane oligomer. In addition, a silicon compound having an organic group such as 4 or more alkoxy groups and an epoxy group or a (meth) acryl group in the siloxane skeleton, an alkylene skeleton in the main chain and 4 or more alkoxy groups and epoxy groups (meta) as substituents. It is preferable to use a silicon compound having an organic group such as an acrylic group.

In the formula (5), ^{R 6} and ^{R 7,} the formula (2) to (4) and ^{R 6} and ^{R 7} in have the same meanings, j is an average polymerization degree of the alkoxysilane monomers, two or more Indicates an integer. In the present invention, the alkoxysilane oligomer is a low-order polymer having a siloxane bond represented by -Si-O- of the alkoxysilane compound, and has at least 4 or more alkoxy groups bonded to silicon atoms. Such an alkoxysilane oligomer is, for example, the presence or absence of use of an acid catalyst in the hydrolysis of the above alkoxysilane compound, the amount used when used, the amount of hydrolysis water present in the reaction system, the reaction temperature, The degree of polymerization can be controlled by adjusting reaction conditions such as reaction time.

  In the present invention, when the (III) silicon compound according to the present invention is the alkoxysilane oligomer, the average number of alkoxy groups bonded to the silicon atom is 4 or more per molecule (the above formula (5 ), J is preferably 2 or more, more preferably 4 to 32 (in the formula (5), j is 2 to 30), and more preferably 6 to 22 (in the formula (5)). , J is more preferably 4 to 20). If the average value of the number of alkoxy groups bonded to the silicon atom is less than the lower limit, the resulting cured product tends to have poor adhesion with an inorganic surface protective film or a metal wiring material, When it exceeds the upper limit, it tends to be difficult to obtain a homogeneous cured product due to insolubilization in a solvent or poor compatibility with a bismaleimide compound.

  In the present invention, the molecular weight of the (III) silicon compound can be determined by gel permeation chromatography (GPC), and the number of alkoxy groups bonded to the silicon atom in the (III) silicon compound is the nucleus of the silicon compound. It can be determined by structural analysis using a magnetic resonance (NMR) method or the like.

  When such a (III) silicon compound having 4 or more alkoxy groups bonded to silicon atoms is used in a photosensitive resin composition containing a conventional polyimide precursor or polybenzoxazole precursor, a polyimide precursor The insoluble matter derived from the silicon compound tends to be easily generated due to the influence of the acidic group in the body and the polybenzoxazole precursor, but in the present invention, the insoluble matter is hardly generated and can be suitably used.

  As the (III) silicon compound according to the present invention, commercially available compounds may be used as appropriate. For example, “KR-513” (average number of alkoxy groups bonded to silicon atoms) manufactured by Shin-Etsu Chemical Co., Ltd. : 4 or more per molecule, organic group: acrylic group), "X-40-2655A" (average value of the number of alkoxy groups bonded to silicon atoms: 4 or more per molecule, organic group: methacryl group), "X-40-1059A" (average number of alkoxy groups bonded to silicon atoms: 4 or more per molecule, organic group: epoxy group), "X-12-984S" (alkoxy groups bonded to silicon atoms) The number of: 1 or more per molecule, organic group: epoxy group) may be used. In addition, as the (III) silicon compound according to the present invention, one kind may be used alone, or two or more kinds may be used in combination.

<Photosensitive resin composition>
The photosensitive resin composition of the present invention contains the (I) bismaleimide compound, the (II) photopolymerization initiator, and the (III) silicon compound. In the photosensitive resin composition of the present invention, the content of the (II) photopolymerization initiator is preferably 0.1 to 15 parts by mass with respect to 100 parts by mass of the (I) bismaleimide compound, More preferably, it is 0.5-5 mass parts. When the content is less than the lower limit, the dimerization reaction by light irradiation does not proceed sufficiently during exposure, and the polymerized film tends to peel from the inorganic surface protective film during development. On the other hand, when the above upper limit is exceeded, the reaction proceeds excessively and the polymerization reaction of the unexposed portion proceeds, so that it tends to be difficult to form a fine pattern.

  Moreover, in the photosensitive resin composition of this invention, it is preferable that content of the said (III) silicon compound is 0.1-3 mass parts with respect to 100 mass parts of said (I) bismaleimide compounds, More preferably, it is 0.1-1 mass part. When the content is less than the lower limit, the adhesive force (adhesive force) with the inorganic surface protective film or the metal wiring material tends to decrease. On the other hand, when the above upper limit is exceeded, there is a tendency that foreign matters are generated due to aggregation of the silicon compound in the cured product.

  The photosensitive resin composition of the present invention is not particularly limited as long as it contains the (I) bismaleimide compound, the (II) photopolymerization initiator, and the (III) silicon compound. It is preferable that the product is dissolved in an organic solvent. Examples of the organic solvent include aromatic solvents such as toluene, xylene and tetralin; ketone solvents such as methyl isobutyl ketone, cyclopentanone and cyclohexanone; cyclic ether solvents such as tetrahydroxyfuran; and organic solvents such as methyl benzoate. These organic solvents may be used alone or in combination of two or more. Furthermore, these organic solvents may contain a solvent in which bismaleimide compounds such as ethyl lactate, propylene glycol monomethyl ether acetate, and γ-butyrolactone are difficult to dissolve, as long as the bismaleimide compound does not precipitate. The concentration when dissolving the (I) bismaleimide compound, the (II) photopolymerization initiator, and the (III) silicon compound in the organic solvent is a photosensitive resin composition from the viewpoint of achieving a suitable viscosity. It is preferable that it is 20-70 mass% as solid content concentration of a thing.

  Further, the photosensitive resin composition of the present invention may further contain a sensitizer. Examples of the sensitizer include 4,4'-bis (diethylamino) benzophenone. In the present invention, when the sensitizer is contained, the content thereof is preferably 0.01 to 2 parts by mass with respect to 100 parts by mass of the (I) bismaleimide compound, and 0.05 to 0 More preferably, it is 5 parts by mass. By including such a sensitizer, the sensitivity of the photosensitive resin composition to light can be further increased.

  Furthermore, the photosensitive resin composition of the present invention may further contain a polyfunctional polymerizable compound. The polyfunctional polymerizable compound refers to a compound having a plurality of polymerizable functional groups such as an acryl group, a methacryl group, an allyl group, and a styryl group. By including the polyfunctional polymerizable compound, the sensitivity of the photosensitive resin composition to light can be further increased. As the polyfunctional polymerizable compound, a polyfunctional acrylate is preferable from the viewpoint of easily causing a crosslinking reaction by photopolymerization. Examples of the polyfunctional acrylate include hydrogenated dicyclopentadienyl diacrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,6 -Butanediol diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, polyethylene glycol 200 diacrylate, polyethylene glycol 400 diacrylate, polyethylene glycol 600 diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, hydroxypivalate ester neopentyl Glycol diacrylate, triethylene glycol diacrylate, bis (acryloxy Toxi) bisphenol A, bis (acryloxyethoxy) tetrabromobisphenol A, tripropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, tris (2-hydroxyethyl) isocyanate, pentaerythritol tetraacrylate, dipentaerythritol Examples include hexaacrylate, dipentaerythritol monohydroxypentaacrylate, styrene, divinylbenzene, diallyl isophthalate, and diallyl phthalate.

  In addition, when the polyfunctional polymerizable compound is contained, the content thereof is preferably 30 parts by mass or less with respect to 100 parts by mass of the (I) bismaleimide compound. When the content of the polyfunctional polymerizable compound exceeds the upper limit, a crosslinking reaction by photopolymerization with the polyfunctional polymerizable compound alone proceeds, and the tensile modulus of the resulting cured product tends to increase. In addition, since the polyfunctional polymerizable compound has high reactivity with respect to radicals, the photopolymerization initiator having at least one structure selected from the group consisting of an oxime structure and a thioxanthone structure suitably used in the present invention. When a highly reactive photopolymerization initiator is used as described above, it tends to be difficult to control the reaction. In general, the addition of a polyfunctional polymerizable compound tends to increase the tensile modulus of the cured product and impair flexibility, but the (I) bismaleimide compound according to the present invention is a polyfunctional polymerizable compound. In the cured product obtained even if it is added, the tensile elastic modulus is hardly increased and the flexibility is not easily impaired. The present inventors infer that this is because the (I) bismaleimide compound according to the present invention has a reactive maleimide group only at both ends and has no crosslinkable reactive group in the molecular chain. . In addition, the photosensitive resin composition of the present invention may further contain a leveling agent, an antifoaming agent and the like within a range that does not impair the effects of the present invention.

The photosensitive resin composition of this invention can be used by the usage method generally known. For example, first, the photosensitive resin composition of the present invention, the viscosity of which is adjusted with the organic solvent, is applied to a support and then dried at 50 to 180 ° C., preferably 80 to 140 ° C. for 5 to 30 minutes. The photosensitive resin composition can be obtained. Examples of the support include a silicon wafer, a ceramic substrate, a rigid substrate, a flexible substrate, and a silicon wafer on which an inorganic surface protective film such as a SiN film or a SiO ₂ film is formed. According to the present invention, even if a silicon wafer on which the inorganic surface protective film is formed is used as a support, a cured product having excellent adhesion (adhesiveness) to the inorganic surface protective film can be obtained.

  Although it does not restrict | limit especially as said application | coating method, Application | coating using a spin coater, a slit coater, a roll coater, screen printing, etc. are mentioned. Among these, for example, as a coating method for a silicon wafer, it is preferable to employ a coating method using a spin coater. Further, the film thickness of the film-like photosensitive resin composition can be arbitrarily adjusted by adjusting the concentration of the photosensitive resin composition or the coating thickness, and is not particularly limited. When the protective film or interlayer insulating film is used, the film thickness after drying is preferably 3 to 50 μm, more preferably 5 to 30 μm, and further preferably 5 to 20 μm. When the film thickness is less than the lower limit, the elements and circuits under the film tend not to be sufficiently protected. On the other hand, when the film thickness exceeds the upper limit, it is difficult to form a fine pattern. It is in. In the present invention, even if the film thickness is 10 μm or more (preferably 10 to 20 μm), a fine pattern can be formed, and the aspect ratio of the opening diameter (Via diameter) of a through hole formed by exposure and development described later. It is possible to form a pattern such that is 0.3 or more (more preferably 0.5 or more).

Next, the film-like photosensitive resin composition thus obtained is exposed by applying a mask having a predetermined pattern shape to photopolymerize the photosensitive resin composition of the present invention. Examples of the exposure method include contact exposure and reduced projection exposure. The exposure wavelength is preferably from 200 to 500 nm of ultraviolet light to visible light, from the viewpoint that a standard reduction projection exposure machine (stepper) can be used, and a fine pattern can be formed. More preferably, it is 310-436 nm, and it is further more preferable that it is 365 nm. The amount of exposure is not particularly limited, but in the present invention, a fine pattern can be formed even with a relatively low amount of exposure, and a large amount of exposure is not required, so it is 2000 mJ / cm ² or less. It is preferably 300 to 2000 mJ / cm ² .

  Next, a polymer film (polymer) having a predetermined pattern can be obtained by performing development by dissolving and removing the unexposed portion of the exposed film-like photosensitive resin composition with a developer. That is, in the exposed area, radicals generated by light irradiation from the photopolymerization initiator react with the maleimide group, and the (I) bismaleimide compound is cross-linked mainly by the dimerization reaction and insolubilized in the developer. . On the other hand, since the unexposed portion is dissolved in the developer, a pattern such as a through hole having a predetermined opening diameter (Via diameter) is obtained by utilizing the difference in solubility between the exposed portion and the unexposed portion in the developer. A polymerized film can be obtained. Examples of the developer include aromatic solvents such as toluene and xylene; cyclic ketone solvents such as cyclopentanone and cyclohexanone; cyclic ether solvents such as tetrahydroxyfuran: and mixed solvents thereof. The developer may further contain an alcohol solvent such as methanol, ethanol, propanol or the like in order to adjust solubility during development. Examples of the developing method include methods such as a spray method, a paddle method, and a dip method.

  Further, it is preferable that the polymer film having a predetermined pattern obtained by the development is further rinsed with an organic solvent such as cyclopentanone or a mixed solvent of cyclopentanone and ethanol. The polymer film after the development preferably has a remaining film ratio of 90% or more from the viewpoint of suppressing occurrence of surface roughness and facilitating dimensional design. In the present invention, the residual film ratio refers to the ratio of the film thickness of the polymer film after development to the film thickness of the film-like photosensitive resin composition after drying (before exposure).

  Next, a cured film (cured product) having a predetermined pattern can be obtained by heating and curing the polymer film having a predetermined pattern obtained by the development. The heating temperature (curing temperature) is preferably 60 to 230 ° C, and more preferably 150 to 230 ° C. The heating time is preferably 30 to 120 minutes. In the present invention, the curing temperature refers to a temperature necessary for thermally curing the maleimide group remaining unreacted during the exposure by a thermal reaction. Such a thermosetting reaction crosslinks the unreacted maleimide group in the photopolymerization described above, but when the photosensitive resin composition of the present invention is used, a conventional polyimide precursor or polybenzoxazole precursor is used. There is no need to increase the curing temperature. This does not require the dehydration ring closure reaction in the (I) bismaleimide compound according to the present invention.

  Thus, the cured film which has a fine pattern can be obtained by using the photosensitive resin composition of this invention. As the pattern, the aspect ratio of the opening diameter (Via diameter) of the formed through hole is preferably 0.3 or more, and more preferably 0.5 or more. In the present invention, the opening diameter is determined by measuring using an optical microscope (Nikon Corporation, “ECLIPSE ME600L”) or a scanning electron microscope (SEM, Hitachi, Ltd., “S-3000N”). it can.

  Moreover, in the cured film obtained using the photosensitive resin composition of this invention, a tensile elasticity modulus will be 2 GPa or less, More preferably, it will be 1 GPa or less, More preferably, it will be 0.05-0.8 GPa. As described above, the cured product obtained by using the photosensitive resin composition of the present invention has a sufficiently low curing temperature and a sufficiently low tensile elastic modulus, so that warpage of a substrate such as a silicon wafer does not occur. And, it becomes excellent in handling property in the subsequent steps. In the present invention, the tensile elastic modulus can be obtained by measuring “Tensilon RTA-250” manufactured by Orientec Co., Ltd. under the conditions of a temperature of 23 ° C. and a tensile speed of 5 mm / min.

  Furthermore, in the cured film obtained using the photosensitive resin composition of the present invention, it is preferable that the elongation at break is 20 to 200% from the viewpoint that cracking can be suppressed. In the present invention, the elongation at break can be determined by measuring “Tensilon RTA-250” manufactured by Orientec Co., Ltd. under conditions of a temperature of 23 ° C. and a tensile speed of 5 mm / min.

As described above, according to the photosensitive resin composition of the present invention, thermosetting at a relatively low temperature and fine pattern formation at a low exposure amount are possible, and the tensile elastic modulus is sufficiently small. A cured product having excellent adhesion to the protective film and the metal wiring material can be obtained. In addition, even when thermosetting, it is possible to thermoset at a relatively low temperature than before, and a cured film having a sufficiently low tensile elastic modulus can be obtained, so that the residual stress generated in the film after curing is reduced. It can be made sufficiently small, and warping of a substrate such as a silicon wafer can be sufficiently suppressed. Furthermore, according to the present invention, a fine pattern can be formed even at an exposure wavelength of 310 to 436 nm (preferably 365 nm) and a low exposure amount of 2000 mJ / cm ² or less, and the aspect ratio of the opening diameter (via diameter) of the through hole. A pattern having a ratio of 0.3 or more (more preferably 0.5 or more) can be formed. This is because the photosensitive resin composition of the present invention has little absorption at 365 nm and the reaction of the maleimide group is mainly a dimerization reaction, so that the polymerization proceeds to the unexposed area by a chain reaction like an acrylic compound. The present inventors infer that this is suppressed.

  As a cured product after photocuring or photothermal curing (curing using both photocuring and thermal curing) obtained using the photosensitive resin composition of the present invention, a surface protective film of a semiconductor element, an interlayer It can be suitably used for at least one film selected from the group consisting of an insulating film and an insulating film of a rewiring layer. In addition, the photosensitive resin composition of the present invention requires a film thickness of 10 μm or more in such a film, and the aspect ratio of the opening diameter (via diameter) of the through hole is 0.3 or more (more preferably). Is particularly effective when patterning is required to be 0.5 or more).

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example. In addition, the patterning performance evaluation and the mechanical property evaluation in each example and comparative example were performed as follows, respectively.

<Patterning performance evaluation>
[Necessary exposure measurement]
First, using a substrate obtained by forming a SiN (silicon nitride) film to a thickness of 0.5 μm (5000 mm) on a silicon wafer, the photosensitivity obtained in each example and comparative example on the formed SiN film. The resin composition was applied using a spin coater and then dried at a temperature of 100 ° C. for 10 minutes to form a film-like photosensitive resin composition on the SiN film. The coating thickness of the photosensitive resin composition was adjusted so that the film thickness of the film-like photosensitive resin composition after drying was 10 μm. Next, a mask for forming a pattern (a circle having a predetermined diameter (Via diameter)) is placed on the formed film-like photosensitive resin composition, and a high-pressure mercury lamp is used from above the mask. Exposure (contact exposure) was performed at each wavelength of 365 to 3000 mJ / cm ² at a wavelength of 365 nm.

  Next, a developer (cyclopentanone: ethanol = 85: 15 (weight ratio)) is dropped onto the film-like photosensitive resin composition after exposure until the whole is immersed in the developer, and the temperature is 23 ° C. and 70 rpm for 80 seconds. After performing the paddle development, the developer was removed at 2000 rpm for 10 seconds. Next, the developer is dropped again on the silicon wafer substrate until the whole is immersed in the developer, rinsed for 10 seconds at a temperature of 23 ° C. and 70 rpm, and then the developer is removed under the conditions of 2000 rpm and 15 seconds to obtain a predetermined pattern. A polymer film having

Next, the film thickness of the film-shaped photosensitive resin composition (polymerized film) after development is measured, and the ratio of the film thickness of the polymer film after development to the film thickness (10 μm) of the film-shaped photosensitive resin composition after drying. The exposure amount required for the (residual film ratio) of 90% or more was defined as the required exposure amount (mJ / cm ² ).

[Aperture diameter (Via diameter) measurement]
In the above required exposure measurement, the developed polymer film obtained at each required exposure was heated at a temperature of 175 ° C. for 60 minutes to obtain a cured film having a predetermined pattern. The pattern formed in the obtained cured film was observed with an optical microscope (Nikon Corporation, “ECLIPSE ME600L”) or a scanning electron microscope (SEM, Hitachi, Ltd., “S-3000N”), and formed with a mask. The diameter of the pattern (Via) opened to the bottom (through hole) is defined as the opening diameter (Via diameter, μm), and the following formula: aspect ratio = (thickness of the cured film) / (opening of the through hole) The aspect ratio of each aperture diameter was determined from the (diameter). It can be said that the finer the pattern is formed, the larger the aspect ratio.

<Evaluation of mechanical properties>
First, the photosensitive resin composition obtained in each Example and Comparative Example was coated on a copper foil having a thickness of 12 μm using a spin coater, and then dried at a temperature of 100 ° C. for 10 minutes, and film-like photosensitive on the copper foil. A resin composition was formed. The coating thickness of the photosensitive resin composition was adjusted so that the film thickness of the film-like photosensitive resin composition after drying was 10 μm. The film-like photosensitive resin composition was exposed using a high-pressure mercury lamp at a wavelength of 365 nm and an exposure amount of 1500 mJ / cm ² , and then cured by heating at a temperature of 175 ° C. for 60 minutes. By removing by etching, a cured film was obtained.

  Subsequently, the obtained cured film was cut into a length of 10 mm, and at a temperature of 23 ° C., using “Tensilon RTA-250” manufactured by Orientec Co., Ltd., the elongation at break (%) and tensile elasticity under the conditions of a tensile speed of 5 mm / min. The rate (MPa) was measured and determined.

<Evaluation of adhesion (adhesiveness)>
First, a 3 mm square polymer film was formed on a SiN film formed on a silicon wafer in the same manner as the above required exposure dose measurement except that a 3 mm square mask was used and the exposure dose was 1500 mJ / cm ^2. It was. Next, a 2 mm square silicon die (thickness 750 μm) with a die attach film (manufactured by Nippon Steel Chemical Co., Ltd., “NEX-130SX”) is temporarily pressed on the formed polymer film (interlayer film) at 100 ° C. for 5 seconds, Furthermore, it was cured at 120 ° C. for 1 hour and bonded to obtain a sample for evaluation laminated in the order of silicon wafer / SiN film / interlayer film (cured product) / die attach film / silicon die. About this sample, the die shear strength (peeling strength) was measured using the die shear test machine (made by DAGE, "4000PXY"), and also the location (fracture mode) where destruction occurred was confirmed and adhesiveness was evaluated.

Further, adhesion was evaluated in the same manner as described above except that the SiN film was changed to a SiO ₂ (silicon oxide) film. Further, adhesion was evaluated in the same manner as described above except that the SiN film was a Cu (copper) sputtered film (about 3 μm thick).

Example 1
First, bismaleimide compound 1 (manufactured by DESIGNER MOLECURES Inc., “BMI-3000”, solid content 100%) 100 parts by mass as component (I), photopolymerization initiator 1 (manufactured by BASF Japan, “IRGACURE” OXE-01 ") 1 part by mass, and silicon compound 1 (Shin-Etsu Chemical Co., Ltd.," X-40-2655A ") 0.25 part by mass as the component (III), the solid content concentration is 50% by mass. Thus, it was added to a solvent (xylene) and sufficiently stirred with a stirrer to dissolve the solid content. Subsequently, this solution was filtered using a 1 μm membrane filter to remove insoluble matters, thereby obtaining a photosensitive resin composition.

As a result of performing patterning performance evaluation using the obtained photosensitive resin composition, it was confirmed that a pattern having an opening diameter of 20 μm (aspect ratio: 0.5) was formed at a necessary exposure amount of 1500 mJ / cm ² . Further, as a result of mechanical property evaluation, the obtained cured film had a tensile elastic modulus of 93 MPa, which was an order of magnitude smaller than that of a photosensitive material made of a conventional polyimide resin or polybenzoxazole resin. Further, the elongation at break was 114%, which was sufficient. Each evaluation result is shown in Table 1 together with the composition of the photosensitive resin composition.

(Example 2)
A photosensitive resin composition was obtained in the same manner as in Example 1 except that the photopolymerization initiator 2 (manufactured by BASF Japan, “IRGACURE OXE-02”) was used as the component (II). As a result of performing patterning performance evaluation using the obtained photosensitive resin composition, it was confirmed that a pattern with an opening diameter of 30 μm (aspect ratio: 0.3) was formed at a necessary exposure amount of 800 mJ / cm ² . In addition, as a result of evaluating the mechanical properties, the obtained cured film had a tensile elastic modulus of 90 MPa and a breaking elongation of 103%. Each evaluation result is shown in Table 1 together with the composition of the photosensitive resin composition.

(Example 3)
A photosensitive resin composition was obtained in the same manner as in Example 1 except that 1 part by mass of silicon compound 2 (manufactured by Shin-Etsu Chemical Co., Ltd., “X-40-1059A”) was used as the component (III). As a result of performing patterning performance evaluation using the obtained photosensitive resin composition, it was confirmed that a pattern having an opening diameter of 20 μm (aspect ratio: 0.5) was formed at a necessary exposure amount of 1500 mJ / cm ² . Further, as a result of evaluating the mechanical properties, the obtained cured film had a tensile elastic modulus of 95 MPa and a breaking elongation of 98%. Each evaluation result is shown in Table 1 together with the composition of the photosensitive resin composition.

Example 4
A photosensitive resin composition was obtained in the same manner as in Example 1 except that 0.5 part by mass of silicon compound 3 (manufactured by Shin-Etsu Chemical Co., Ltd., “X-12-984S”) was used as the component (III). . As a result of performing patterning performance evaluation using the obtained photosensitive resin composition, it was confirmed that a pattern having an opening diameter of 20 μm (aspect ratio: 0.5) was formed at a necessary exposure amount of 1500 mJ / cm ² . Moreover, as a result of evaluating the mechanical properties, the obtained cured film had a tensile elastic modulus of 92 MPa and a breaking elongation of 101%. Each evaluation result is shown in Table 1 together with the composition of the photosensitive resin composition. Furthermore, Table 3 shows the results of adhesion evaluation using the obtained photosensitive resin composition.

(Example 5)
(II) Photopolymerization initiator 3 (manufactured by Nippon Kayaku Co., Ltd., “DETX-S”) was used as component (II), and 1 part by mass of silicon compound 2 was used as component (III). Thus, a photosensitive resin composition was obtained. As a result of performing patterning performance evaluation using the obtained photosensitive resin composition, it was confirmed that a pattern having an opening diameter of 25 μm (aspect ratio: 0.4) was formed at a necessary exposure amount of 1500 mJ / cm ² . Further, as a result of evaluating the mechanical properties, the obtained cured film had a tensile modulus of 89 MPa and a breaking elongation of 105%. Each evaluation result is shown in Table 1 together with the composition of the photosensitive resin composition.

(Example 6)
A photosensitive resin composition was obtained in the same manner as in Example 1 except that 1 part by mass of silicon compound 4 (manufactured by Shin-Etsu Chemical Co., Ltd., “KR-513”) was used as the component (III). As a result of performing patterning performance evaluation using the obtained photosensitive resin composition, it was confirmed that a pattern having an opening diameter of 20 μm (aspect ratio: 0.5) was formed at a necessary exposure amount of 1500 mJ / cm ² . Further, as a result of mechanical property evaluation, the obtained cured film had a tensile elastic modulus of 103 MPa and a breaking elongation of 95%. Each evaluation result is shown in Table 1 together with the composition of the photosensitive resin composition.

(Example 7)
(III) As in Example 1, except that 1 part by mass of silicon compound 2 was used as the component and 5 parts by mass of a polyfunctional polymerizable compound (manufactured by Kyoeisha Chemical Co., Ltd., “Light acrylate DCP-A”) was added. Thus, a photosensitive resin composition was obtained. As a result of performing patterning performance evaluation using the obtained photosensitive resin composition, it was confirmed that a pattern having an opening diameter of 25 μm (aspect ratio: 0.4) was formed at a necessary exposure amount of 1000 mJ / cm ² . As a result of evaluating the mechanical properties, the obtained cured film had a tensile modulus of 92 MPa and a breaking elongation of 46%. Each evaluation result is shown in Table 1 together with the composition of the photosensitive resin composition.

(Comparative Example 1)
A photosensitive resin composition was obtained in the same manner as in Example 1 except that the photopolymerization initiator 1 was not used. Although patterning performance evaluation and mechanical property evaluation were performed using the obtained photosensitive resin composition, a polymerized film could not be obtained even with an exposure amount of 3000 mJ / cm ² , and all the exposed areas were dissolved during development, A pattern could not be formed. Each evaluation result is shown in Table 2 together with the composition of the photosensitive resin composition.

(Comparative Example 2)
A photosensitive resin composition was obtained in the same manner as in Example 1 except that the silicon compound 1 was not used. Patterning performance evaluation and mechanical property evaluation were performed using the obtained photosensitive resin composition, but the polymerized film peeled off from the SiN film formed on the silicon wafer at the time of development even at an exposure amount of 3000 mJ / cm ² and cured. A membrane could not be obtained. Each evaluation result is shown in Table 2 together with the composition of the photosensitive resin composition.

(Comparative Example 3)
Implemented except that 1 part by mass of comparative silicon compound 1 (manufactured by Shin-Etsu Chemical Co., Ltd., “KBM-5103”, number of alkoxy groups bonded to silicon atom: 3 per molecule) was used instead of silicon compound 1. A photosensitive resin composition was obtained in the same manner as in Example 1. Patterning performance evaluation and mechanical property evaluation were performed using the obtained photosensitive resin composition, but the polymerized film peeled off from the SiN film formed on the silicon wafer at the time of development even at an exposure amount of 3000 mJ / cm ² and cured. A membrane could not be obtained. Each evaluation result is shown in Table 2 together with the composition of the photosensitive resin composition.

(Comparative Example 4)
First, in a 300 ml three-necked flask in which nitrogen was allowed to flow, 14.3 g of dimer diamine (manufactured by Croda Japan, “PRIAMINE 1074”) was dissolved in 56 g of N, N′-dimethylacetamide and 24 g of xylene. Next, 5.7 g of pyromellitic anhydride was added to the solution at room temperature (23 ° C.) with stirring, and the mixture was stirred for 1 hour. Thereafter, a dehydration trap was attached to the three-necked flask and stirred at a temperature of 160 ° C. for 6 hours while dehydrating and refluxing to obtain a polyimide compound containing no maleimide structure (Comparative Compound 1). Subsequently, it replaced with the bismaleimide compound 1, and obtained the photosensitive resin composition like Example 1 except having used the said comparative compound 1 (100 mass parts of solid content). Although patterning performance evaluation and mechanical property evaluation were performed using the obtained photosensitive resin composition, a polymerized film could not be obtained even with an exposure amount of 3000 mJ / cm ² , and all the exposed areas were dissolved during development, A pattern could not be formed. Each evaluation result is shown in Table 2 together with the composition of the photosensitive resin composition.

As is clear from the results shown in Table 1, when the photosensitive resin composition of the present invention obtained in Examples 1 to 7 was used, a sufficiently small opening diameter was obtained even at a low exposure amount. It was confirmed that it was possible to form a fine pattern. Further, it was confirmed that a fine pattern having an aspect ratio of 0.3 or more can be formed by irradiation with light of 365 nm even when the film thickness is 10 μm. Furthermore, the photosensitive resin composition of the present invention obtained in Examples 1 to 7 has a sufficiently small tensile elastic modulus even without thermal curing at a high temperature, and has good adhesion to an adherend such as an inorganic surface protective film. It was confirmed that an excellent cured product can be obtained. On the other hand, when the photosensitive resin composition obtained in Comparative Examples 1 to 4 was used, a pattern could not be formed even with an exposure amount of 3000 mJ / cm ² , and it was used as a photosensitive resin composition. It was confirmed that it was not possible.

  Further, as is apparent from the results shown in Table 3, in the sample for evaluation comprising a cured product obtained using the photosensitive resin composition of the present invention as an interlayer film, the die shear strength is sufficiently high, Since the location where the fracture occurred is not a bonded surface between the cured product and the adherend but a silicon die, the cured product of the present invention is made of an inorganic surface protective film (silicon nitride film, silicon oxide film, etc.) It was confirmed that it was excellent in adhesiveness (adhesiveness) with wiring materials (copper etc.).

As described above, according to the present invention, it is possible to form a fine pattern with a relatively low exposure (2000 mJ / cm ² or less), and it is not necessary to perform thermosetting at a high temperature as in the prior art. Photosensitivity capable of obtaining a cured product having a sufficiently small elastic modulus and excellent adhesion to inorganic surface protective films (silicon nitride film, silicon oxide film, etc.) and conductive metal wiring materials (copper, etc.) A resin composition, a cured product using the resin composition, and a semiconductor element can be provided.

  Further, according to the present invention, thermosetting is not required, and even when thermosetting is performed as required, thermosetting at a relatively low temperature (60 to 230 ° C.) is possible, and the tensile elastic modulus. Therefore, a sufficiently small cured product can be obtained, so that the residual stress generated in the cured film can be sufficiently reduced, and warpage of the silicon wafer can be sufficiently suppressed. Furthermore, according to the present invention, even if the film thickness is large, it is possible to form a fine pattern by irradiation with 365 nm light. Therefore, such a photosensitive resin composition of the present invention is very useful as a surface protective film of a semiconductor element, an interlayer insulating film, an insulating film of a rewiring layer, and the like.

Claims (11)

  (I) a bismaleimide compound having a cyclic imide bond and a divalent hydrocarbon group (a) derived from dimer acid, (II) a photopolymerization initiator, and (III) four alkoxy groups bonded to a silicon atom. A photosensitive resin composition comprising the silicon compound as described above.   The (I) bismaleimide compound is obtained by reacting a diamine (A) derived from a dimer acid, a tetracarboxylic dianhydride, and a maleic anhydride, or a dimer acid. Bismaleimide obtained by reacting derivatized diamine (A), organic diamine (B) other than diamine (A) derived from dimer acid, tetracarboxylic dianhydride, and maleic anhydride The photosensitive resin composition according to claim 1, wherein the photosensitive resin composition is a compound. The (I) bismaleimide compound is represented by the following general formula (1):

[In Formula (1), R ¹ represents a divalent hydrocarbon group (a) derived from dimer acid, and R ² represents a divalent other than the divalent hydrocarbon group (a) derived from dimer acid. R ³ represents a divalent organic group other than the divalent hydrocarbon group (a) derived from dimer acid and the divalent hydrocarbon group (a) derived from dimer acid. (B) represents any one selected from the group consisting of R ⁴ and R ^{5, which} may be the same or different, each represents a tetravalent organic group, and m is an integer of 1 to 30. , N is an integer of 0-30, and when m is 2 or more, a plurality of R ¹ and R ⁴ may be the same or different, and when n is 2 or more, a plurality of R ² and R 4 are present. ⁵ may be the same or different. ]
The photosensitive resin composition according to claim 1, wherein the photosensitive resin composition is a bismaleimide compound represented by the formula:   The said (II) photoinitiator is a compound which has at least any 1 type of structure selected from the group which consists of an oxime structure and a thioxanthone structure, The any one of Claims 1-3 characterized by the above-mentioned. The photosensitive resin composition according to item.   The content of the (III) silicon compound is 0.1 to 3 parts by mass with respect to 100 parts by mass of the (I) bismaleimide compound. The photosensitive resin composition as described in 2.   The content of the (II) photopolymerization initiator is 0.1 to 15 parts by mass with respect to 100 parts by mass of the (I) bismaleimide compound. The photosensitive resin composition of one term. The photosensitive property according to any one of claims 1 to 6, wherein a residual film ratio of an exposed portion after exposure is 90% or more at an exposure wavelength of 365 nm and an exposure amount of 300 to 2000 mJ / cm ² . Resin composition.   The photosensitive resin composition according to any one of claims 1 to 7, wherein a tensile elastic modulus after curing is 2 GPa or less.   Curing temperature is 60-230 degreeC, The photosensitive resin composition as described in any one of Claims 1-8 characterized by the above-mentioned.   A cured product obtained by photocuring or photothermally curing the photosensitive resin composition according to any one of claims 1 to 9.   A semiconductor device comprising the cured product according to claim 10 as at least one selected from the group consisting of a surface protective film, an interlayer insulating film, and an insulating film of a rewiring layer.