JP2017044964A - Photosensitive resin composition, cured product and production method of patterned cured film using the composition, and semiconductor element and electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition excellent in adhesiveness to silicon after a pressure cooker test (PCT), a cured product and a production method of patterned cured film using the above composition, a semiconductor element having the above cured product as an interlayer insulation layer or a surface protective layer, and an electronic device having the semiconductor element.SOLUTION: The photosensitive resin composition comprises (A) a bismaleimide compound, (B) a photopolymerization initiator, and (C) a silane compound containing a thiol group. The production method of a patterned cured film includes: a step of applying and drying the above photosensitive resin composition on a part of or the whole surface of a substrate to form a resin film; a step of partially or wholly exposing the resin film; a step of developing the exposed resin film to form a patterned resin film; and a step of heating the patterned resin film.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a photosensitive resin composition, a cured product using the same, a method for producing a patterned cured film, a semiconductor element, and an electronic device.

In recent years, with the high integration and miniaturization of semiconductor elements, the surface protective layer and interlayer insulating layer of semiconductor elements have better electrical characteristics (dielectric constant, etc.), heat resistance (thermal expansion coefficient, glass transition temperature, etc.), It is required to have mechanical properties (elastic modulus, elongation at break, etc.). As a material for forming the surface protective layer and the interlayer insulating layer having such characteristics, a negative photosensitive resin composition containing a polyimide precursor (see, for example, Patent Documents 1 and 2), phenolic A positive photosensitive resin composition containing an alkali-soluble resin having a hydroxyl group (see, for example, Patent Documents 3, 4, and 5) has been developed. These photosensitive resin compositions are applied onto a substrate and dried to form a resin film, and the resin film is exposed and developed to obtain a patterned resin film (patterned resin film). A patterned cured film (patterned cured film) can be formed by heating and curing the patterned resin film, and the patterned cured film can be used as a surface protective layer and an interlayer insulating layer.
However, when these photosensitive resin compositions are used, the cured film shrinks due to the ring-closing reaction or the crosslinking reaction that occurs during heat curing, and the substrate is warped. This warpage of the substrate causes various problems such as a decrease in the handleability of the substrate during the manufacturing process. In order to solve this problem, a negative photosensitive resin composition using a bismaleimide compound having a flexible skeleton introduced as a base resin has been developed (see, for example, Patent Document 6).

Japanese Patent Laid-Open No. 2003-122004 JP-A-11-316462 JP 2008-309885 A JP 2007-57595 A International Publication No. 2010/073948 JP 2013-83958 A

When using the photosensitive resin composition as a surface protective layer and an interlayer insulating layer of a semiconductor element, it is necessary to have excellent adhesion to a metal wiring such as a silicon substrate and copper. It is known that when the adhesiveness between the photosensitive resin composition and the silicon substrate or the metal wiring is poor, disconnection due to peeling or package cracking occurs.
Therefore, when the adhesiveness to the silicon and copper after the pressure cooker test (PCT) of the photosensitive resin composition using the bismaleimide resin was evaluated, the adhesiveness to copper was good even after the PCT. It was found that the adhesion to silicon was low.

  Therefore, an object of the present invention is to provide a photosensitive resin composition having excellent adhesiveness with silicon even after PCT. Another object is to provide a method for producing a cured product and a patterned cured film using the photosensitive resin composition, a semiconductor element having the cured product as an interlayer insulating layer or a surface protective layer, and an electronic device having the semiconductor element. To do.

The present invention relates to the following.
<1> A photosensitive resin composition containing (A) a bismaleimide compound, (B) a photopolymerization initiator, and (C) a silane compound containing a thiol group.
<2> A cured product of the photosensitive resin composition according to <1>.
<3> A step of applying and drying the photosensitive resin composition according to <1> to a part or the entire surface of the substrate to form a resin film, a step of exposing a part or the entire surface of the resin film, and a post-exposure step The manufacturing method of a pattern cured film which has the process of developing a resin film and forming a pattern resin film, and the process of heating a pattern resin film.
<4> A semiconductor element having the cured product according to <3> as an interlayer insulating layer.
<5> A semiconductor element having the cured product according to <3> as a surface protective layer.
<6> An electronic device having the semiconductor element according to <4> or <5>.

  According to the present invention, it is possible to provide a photosensitive resin composition having a low stress and less warping of a substrate even after heat curing and having excellent adhesion to silicon. Moreover, the manufacturing method of the cured film and pattern cured film using this photosensitive resin composition, the semiconductor element which has a cured film as an interlayer insulation layer and a surface protective layer, and the electronic device which has this semiconductor element can be provided.

It is (a) schematic perspective view and (b) schematic end elevation explaining one Embodiment of the manufacturing process of a semiconductor element. It is (a) schematic perspective view and (b) schematic end elevation explaining one Embodiment of the manufacturing process of a semiconductor element. It is (a) schematic perspective view and (b) schematic end elevation explaining one Embodiment of the manufacturing process of a semiconductor element. It is (a) schematic perspective view and (b) schematic end elevation explaining one Embodiment of the manufacturing process of a semiconductor element. It is (a) schematic perspective view and (b) schematic end elevation explaining one Embodiment of the manufacturing process of a semiconductor element. It is a schematic sectional drawing which shows one Embodiment of a semiconductor element. It is a schematic sectional drawing which shows one Embodiment of a semiconductor element.

  Preferred embodiments of the present invention will be described in detail. In addition, this invention is not limited to the following embodiment. In addition, in this specification, when a numerical range is expressed using “to”, a range including the numerical values described before and after the numerical value is indicated as a minimum value and a maximum value, respectively. In the present specification, “A or B” may include either one of A or B, or may include both. In addition, the materials exemplified below may be used alone or in combination of two or more unless otherwise specified. In the present specification, the content of each component in the composition is the total amount of the plurality of substances present in the composition unless there is a specific notice when there are a plurality of substances corresponding to each component in the composition. Means.

[Photosensitive resin composition]
The photosensitive resin composition of the present invention is
(A) a bismaleimide compound (also referred to as (A) component),
(B) a photopolymerization initiator (also referred to as (B) component)),
(C) a silane compound containing a thiol group (also referred to as (C) component),
Containing.
First, each component contained in the photosensitive resin composition will be described.

<(A) component; bismaleimide compound>
The manufacturing method of the bismaleimide compound (bismaleimide resin) used by this invention is not specifically limited. For example, it can be obtained by condensing an acid dianhydride and a long-chain diamine to produce an amine-terminated compound and then condensing with an excess of maleic anhydride.

  Examples of the acid dianhydride include polybutadiene-graft-maleic anhydride, polyethylene-graft-maleic anhydride, polyethylene-maleic anhydride alternating copolymer, polymaleic anhydride-1-octadecene alternating copolymer, polypropylene- Graft-maleic anhydride, poly (styrene-co-maleic anhydride), pyromellitic anhydride, maleic anhydride, succinic anhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,4,5 , 8-Naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, bicyclo (2.2.2) oct-7-ene-2,3,5,6-tetra Carboxylic acid dianhydride, diethylenetriaminepentaacetic acid dianhydride, ethylenediaminetetraacetic acid dianhydride, 3,3 ′, 4,4′-benzo Phenonetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 4,4′-oxydiphthalic anhydride, 3,3 ′, 4,4′-diphenylsulfone Tetracarboxylic dianhydride, 2,2'-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, 4,4'-bisphenol A diphthalic anhydride, 5- (2,5-dioxy Tetrahydro) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, ethylene glycol bis (trimellitic anhydride), hydroquinone diphthalic anhydride, allyl nadic anhydride, 2 -Octen-1-yl succinic anhydride, phthalic anhydride, 1,2,3,6-tetrahydrophthalic anhydride, 3,4,5,6 Tetrahydrophthalic anhydride, 1,8-naphthalic anhydride, glutaric anhydride, dodecenyl succinic anhydride, hexadecenyl succinic anhydride, hexahydrophthalic anhydride, methyl hexahydrophthalic anhydride, tetra Examples include decenyl succinic anhydride, and the like.

  Examples of the diamine include 1,10-diaminodecane, 1,12-diaminododecane, dimer diamine, 1,2-diamino-2-methylpropane, 1,2-diaminocyclohexane, 1,2-diaminopropane, 1, 3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,7-diaminoheptane, 1,8-diaminomentane, 1,8-diaminooctane, 1,9-diaminononane, 3,3 ′ -Diamino-N-methyldipropylamine, diaminomaleonitrile, 1,3-diaminopentane, 9,10-diaminophenanthrene, 4,4'-diaminooctafluorobiphenyl, 3,5-diaminobenzoic acid, 3,7- Diamino-2-methoxyfluorene, 4,4'-diaminobenzophenone, 3,4-diaminobenzene Zophenone, 3,4-diaminotoluene, 2,6-diaminoanthraquinone, 2,6-diaminotoluene, 2,3-diaminotoluene, 1,8-diaminonaphthalene, 2,4-diaminotoluene, 2,5-diaminotoluene 1,4-diaminoanthraquinone, 1,5-diaminoanthraquinone, 1,5-diaminonaphthalene, 1,2-diaminoanthraquinone, 2,4-cumenediamine, 1,3-bisaminomethylbenzene, 1,3-bis Aminomethylcyclohexane, 2-chloro-1,4-diaminobenzene, 1,4-diamino-2,5-dichlorobenzene, 1,4-diamino-2,5-dimethylbenzene, 4,4′-diamino-2, 2'-bistrifluoromethylbiphenyl, bis (amino-3-chloropheny) ethane, bis (4-a No-3,5-dimethylphenyl) methane, bis (4-amino-3,5-diethylphenyl) methane, bis (4-amino-3-ethyldiaminofluorene, diaminobenzoic acid, 2,3-diaminonaphthalene, 2 , 3-Diaminophenol-5-methylphenyl) methane, bis (4-amino-3-methylphenyl) methane, bis (4-amino-3-ethylphenyl) methane, 4,4′-diaminophenylsulfone, 3, 3'-diaminophenylsulfone, 2,2-bis (4, (4-aminophenoxy) phenyl) sulfone, 2,2-bis (4- (3-aminophenoxy) phenyl) sulfone, 4,4'-oxydi Aniline, 4,4′-diaminodiphenyl sulfide, 3,4′-oxydianiline, 2,2-bis (4- (4-aminophenoxy) Nyl) propane, 1,3-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′-diamino-3,3′-dihydroxybiphenyl, 4,4 ′ -Diamino-3,3'-dimethylbiphenyl, 4,4'-diamino-3,3'-dimethoxybiphenyl, 1,3-bis [2- (4-aminophenyl) -2-propyl] benzene (Bisaniline M) , Α, α′-bis (4-aminophenyl) -1,4-diisopropylbenzene (Bisaniline P), 9,9-bis (4-aminophenyl) fluorene, o-tolidine sulfone, methylene bis (anthranilic acid), 1 , 3-bis (4-aminophenoxy) -2,2-dimethylpropane, 1,3-bis (4-aminophenoxy) propane, 4-bis (4-aminophenoxy) butane, 1,5-bis (4-aminophenoxy) butane, 2,3,5,6-tetramethyl-1,4-phenylenediamine, 3,3 ′, 5,5 '-Tetramethylbenzidine, 4,4'-diaminobenzanilide, 2,2-bis (4-aminophenyl) hexafluoropropane, polyoxyalkylenediamines (for example, Jeffamine D-230 from Huntsman, D400, D-2000 and D-4000), 1,3-cyclohexanebis (methylamine), m-xylylenediamine, p-xylylenediamine, bis (4-amino-3-methylcyclohexyl) methane, 1,2 -Bis (2-aminoethoxy) ethane, 3 (4), 8 (9) -bis (aminomethyl) tricyclo (5 2.1.02,6) decane, Preamine1074 (Croda Inc.), manufactured by Preamine1075 (Croda), and their analogs.

  Maleic anhydride is represented by the following formula (1), the following general formula (2), the following general formula (3), and the following general formula (4). It is preferable to include at least one selected from the group consisting of the above compounds.

［一般式（２）において、Ｒ^２は、アルキル基、アリール基又はハロゲン原子を示す。］

[In General Formula (2), R ² represents an alkyl group, an aryl group, or a halogen atom. ]

［一般式（３）において、Ｒ^３及びＲ^４は、それぞれ独立してアルキル基、アリール基又はハロゲン原子を示す。］

[In General Formula (3), R ³ and R ⁴ each independently represents an alkyl group, an aryl group, or a halogen atom. ]

［一般式（４）において、Ｒ^５は、プロピレン基又はブチレン基を示す。］

[In General Formula (4), R ⁵ represents a propylene group or a butylene group. ]

  A commercially available bismaleimide compound (bismaleimide resin) can also be used. Examples of commercially available bismaleimide resins include bismaleimide resins manufactured by Designa Molecules Incorporated, Inc., specifically, BMI-1500 represented by the following formula (5), and formula (6) BMI-1700 shown, and BMI-3000, BMI-5000, BMI-9000, etc. shown by Formula (7) are mentioned.

式（５）中：ｎは１から１０の整数である。

In formula (5): n is an integer of 1 to 10.

式（６）中：ｎは１から１０の整数である。

In formula (6): n is an integer of 1 to 10.

式（７）中：ｎは１から１０の整数である。

In formula (7): n is an integer of 1 to 10.

  When using BMI-3000 represented by the formula (IV), the weight average molecular weight is preferably 1,000 to 30,000, more preferably 5,000 to 20,000, from the viewpoint of sensitivity and the shape of the opening pattern after development. preferable.

<(B) component; photopolymerization initiator>
(B) The photoinitiator of a component is a compound which produces | generates a radical by light. (B) The photopolymerization initiator is not particularly limited as long as it matches the light wavelength of the exposure machine used and the wavelength required for function expression. For example, benzophenone, N, N′-tetra Methyl-4,4′-diaminobenzophenone (Michler ketone), N, N′-tetraethyl-4,4′-diaminobenzophenone, 4-methoxy-4′-dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1- Aromatic ketones such as (4-morpholinophenyl) -butanone-1,2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propanone-1, 2-ethylanthraquinone, phenanthrenequinone, 2-tert -Butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone Non, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenantharaquinone, 2-methyl-1,4-naphthoquinone, 2, Quinones such as 3-dimethylanthraquinone; benzoin ether compounds such as benzoin methyl ether, benzoin ethyl ether, and benzoin phenyl ether; benzoin compounds such as benzoin, methyl benzoin, and ethyl benzoin; 1,2-octanedione-1- [4- (Phenylthio) phenyl] -2- (O-benzoyloxime), 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] ethanone 1- (O-acetyloxime), etc. Oxime ester compound; Ben Benzyl derivatives such as rudimethyl ketal; 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer, 2- (O-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenyl 2,4,5-triarylimidazole dimers such as imidazole dimer; acridine derivatives such as 9-phenylacridine and 1,7-bis (9,9'-acridinyl) heptane; N-phenylglycine, N- Examples include phenylglycine derivatives, coumarin compounds, and oxazole compounds. Further, the substituents of the aryl groups of two 2,4,5-triarylimidazoles may be the same to give the target compound, or differently give an asymmetric compound. Moreover, you may combine a thioxanthone type compound and a tertiary amine compound like the combination of diethyl thioxanthone and dimethylaminobenzoic acid.

  Among these, an oxime ester compound is preferable from the viewpoint of the remaining film ratio after development and pattern forming properties. Examples of the oxime ester compound include (1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)] and ethanone, 1- [9-ethyl-6- (2-methyl). Benzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime) and the like.

<(C) component; silane compound containing a thiol group>
The silane compound containing the thiol group as the component (C) is added for the purpose of improving the adhesion to the substrate and the metal wiring. In order to improve the adhesion to silicon, a silane coupling agent containing a thiol group is used.
Examples of the silane compound (silane coupling agent) having a thiol group as component (C) include 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane.

  The photosensitive resin composition of the present invention can be developed using a solvent such as cyclopentanone. Further, by using the above-described photosensitive resin composition of the present invention, sufficiently high sensitivity and resolution, low stress after heating and curing, less warping of the substrate, and good adhesion and thermal shock after PCT. It is possible to form a cured pattern film.

[Method for producing cured product and patterned cured film]
The cured product of the present invention is a cured product of the photosensitive resin composition of the present invention. The cured product of the present invention can be obtained by heating the photosensitive resin composition of the present invention. Further, the cured product of the present invention may be a patterned cured film in which a pattern is formed. A pattern cured film is obtained by the manufacturing method of the pattern cured film mentioned later, for example.
Next, the manufacturing method of a pattern cured film is demonstrated. The method for producing a cured pattern film of the present invention comprises a step of applying and drying the photosensitive resin composition of the present invention on part or the entire surface of a substrate to form a resin film (coating / drying (film formation) step), a resin A step of exposing part or the entire surface of the film (exposure step), a step of developing the exposed resin film with a solvent to form a pattern resin film (development step), and a step of heating the pattern resin film (heat treatment) Process). Hereinafter, each step will be described.

<Application / drying (film formation) process>
The coating / drying (film formation) step is a step of forming a resin film by applying and drying the photosensitive resin composition of the present invention on a part or the entire surface of the substrate.
First, the photosensitive resin composition of the present invention is applied on a substrate and dried to form a resin film. In this step, the photosensitive resin composition of the present invention is spin-coated using a spinner or the like on a glass substrate, a semiconductor, a metal oxide insulator (for example, TiO ₂ , SiO ₂ ), silicon nitride, or the like. To form a coating film. Although there is no restriction | limiting in particular in the thickness of a coating film, it is preferable that it is 0.1-40 micrometers. The substrate on which this coating film has been formed is dried using a hot plate, oven, or the like. Although there is no restriction | limiting in particular in drying temperature and drying time, It is preferable to carry out at 1-80 minutes at 80-140 degreeC. Thereby, a photosensitive resin film is formed on the substrate. Although there is no restriction | limiting in particular in the thickness of the photosensitive resin film | membrane, it is preferable that it is 0.1-40 micrometers.

<Exposure process>
The exposure step is a step of exposing part or the entire surface of the resin film.
In the exposure step, the photosensitive resin film formed on the substrate is irradiated with actinic rays such as ultraviolet rays, visible rays, and radiations through a mask. In addition, after exposure, post-exposure heating (PEB) can also be performed as needed from the viewpoint of improving pattern formability. The temperature for heating after exposure is preferably 70 to 140 ° C., and the time for heating after exposure is preferably 1 to 5 minutes.

<Development process>
The developing step is a step of developing the exposed resin film with a solvent to form a patterned resin film.
In the development step, the resin film is patterned by removing an unexposed portion of the resin film after the exposure step with a developer, and a patterned resin film is obtained. As a method of performing development using a developer, for example, the developer is placed on a photosensitive resin film by a method such as shower development, spray development, immersion development, paddle development, and the like, under conditions of 18 to 40 ° C., 30 Leave for ~ 360 seconds. After leaving, the pattern resin film is washed by spin drying.

<Heat treatment process>
The heat treatment step is a step of heating the pattern resin film.
In the heat treatment step, the pattern cured film can be formed by heat treating the pattern resin film. The heating temperature in the heat treatment step is preferably 250 ° C. or lower, more preferably 225 ° C. or lower, and further preferably 140 to 200 ° C. from the viewpoint of sufficiently preventing damage to the semiconductor device due to heat.

  The heat treatment can be performed using, for example, an oven such as a quartz tube furnace, a hot plate, rapid thermal annealing, a vertical diffusion furnace, an infrared curing furnace, an electron beam curing furnace, or a microwave curing furnace. In addition, either air or an inert atmosphere such as nitrogen can be selected. However, it is preferable to perform the process under nitrogen because the oxidation of the pattern can be prevented. Since the preferable heating temperature range described above is lower than the conventional heating temperature, damage to the substrate and the semiconductor device can be reduced. Therefore, an electronic device can be manufactured with a good yield by using the method for manufacturing a patterned cured film of the present invention. It also leads to energy savings in the process. Furthermore, according to the photosensitive resin composition of the present invention, since the volume shrinkage (curing shrinkage) in the heat treatment step found in photosensitive polyimide or the like is small, it is possible to prevent a reduction in dimensional accuracy.

  The heat treatment time in the heat treatment step may be a time sufficient for the photosensitive resin composition to cure, but is preferably about 5 hours or less in view of work efficiency.

  The heat treatment can also be performed using a microwave curing device or a variable frequency microwave curing device in addition to the above-described oven. By using these devices, it is possible to effectively heat the photosensitive resin film while keeping the temperature of the substrate and the semiconductor device at, for example, 200 ° C. or less (J. Photopolym. Sci. Technol., 18). 327-332 (2005)).

  According to the above-described method for producing a pattern cured film of the present invention, the pattern cured film having sufficiently high sensitivity and resolution, low stress even after heat curing, low substrate warpage, and excellent adhesion and thermal shock after PCT. Is obtained.

[Interlayer insulation layer, surface protective layer]
The cured product of the present invention can be used as an interlayer insulating layer or a surface protective layer of a semiconductor element.

[Semiconductor element]
Moreover, the semiconductor element of this invention has the hardened | cured material of this invention as an interlayer insulation layer or a surface protective layer.
Although there is no restriction | limiting in particular in the semiconductor element of this invention, A memory, a package, etc. which have a multilayer wiring structure, a rewiring structure, etc. may be sufficient.
Here, an example of the manufacturing process of the semiconductor element will be described with reference to the drawings. 1 to 5 are a schematic perspective view and a schematic end view showing an embodiment of a manufacturing process of a semiconductor device having a multilayer wiring structure. 1 to 5, (a) is a schematic perspective view, and (b) is a schematic end view showing Ib-Ib to Vb-Vb end surfaces in (a), respectively.

  First, the structure 100 shown in FIG. 1 is prepared. The structure 100 includes a semiconductor substrate 1 such as a Si substrate having circuit elements, a protective film 2 such as a silicon oxide film covering the semiconductor substrate 1 and having a predetermined pattern from which the circuit elements are exposed, and exposed circuit elements. A first conductor layer 3 formed thereon, and an interlayer insulating layer 4 made of polyimide resin or the like formed on the protective film 2 and the first conductor layer 3 by a spin coat method or the like are provided.

  Next, a photosensitive resin layer 5 having a window portion 6A is formed on the interlayer insulating layer 4 to obtain a structure 200 shown in FIG. The photosensitive resin layer 5 is formed, for example, by applying a photosensitive resin such as chlorinated rubber, phenol novolac, polyhydroxystyrene, or polyacrylate ester by a spin coating method. The window 6A is formed so that a predetermined portion of the interlayer insulating layer 4 is exposed by a known photolithography technique.

  After the interlayer insulating layer 4 is etched to form the window 6B, the photosensitive resin layer 5 is removed to obtain the structure 300 shown in FIG. For etching the interlayer insulating layer 4, dry etching means using a gas such as oxygen or carbon tetrafluoride can be used. By this etching, the portion of the interlayer insulating layer 4 corresponding to the window portion 6A is selectively removed, and the interlayer insulating layer 4 provided with the window portion 6B so that the first conductor layer 3 is exposed is obtained. Next, the photosensitive resin layer 5 is removed using an etching solution that corrodes the photosensitive resin layer 5 without corroding the first conductor layer 3 exposed from the window portion 6B.

  Furthermore, the 2nd conductor layer 7 is formed in the part corresponding to the window part 6B, and the structure 400 shown in FIG. 4 is obtained. A known photolithography technique can be used to form the second conductor layer 7. As a result, the second conductor layer 7 and the first conductor layer 3 are electrically connected.

  Finally, the surface protective layer 8 is formed on the interlayer insulating layer 4 and the second conductor layer 7 to obtain the semiconductor element 500 shown in FIG. In the present embodiment, the surface protective layer 8 is formed as follows. First, the photosensitive resin composition described above is applied onto the interlayer insulating layer 4 and the second conductor layer 7 by spin coating, and dried to form a photosensitive resin film. Next, light irradiation is performed on a predetermined portion through a mask on which a pattern corresponding to the window portion 6C is drawn, and then the unexposed resin film is developed to form a patterned resin film. Thereafter, the pattern resin film used as the surface protective layer 8 is formed by curing the pattern resin film by heating. The surface protective layer 8 protects the first conductor layer 3 and the second conductor layer 7 from external stress, α rays, and the like, and the semiconductor element 500 using the surface protective layer 8 of the present embodiment is reliable. Excellent in properties.

In the above-described embodiment, a method for manufacturing a semiconductor device having a two-layer wiring structure has been described. However, when a multilayer wiring structure having three or more layers is formed, the above steps are repeated to form each layer. Can do. That is, it is possible to form a multilayer pattern by repeating each step of forming the interlayer insulating layer 4 and each step of forming the surface protective layer 8. In the above example, not only the surface protective layer 8 but also the interlayer insulating layer 4 can be formed using the photosensitive resin composition of the present embodiment.
The electronic device of the present invention is not limited to one having a surface protective layer, a cover coat layer, or an interlayer insulating layer formed using the above-described negative photosensitive resin composition, and can have various structures.

  6 and 7 are schematic cross-sectional views showing an embodiment of a semiconductor device having a rewiring structure. Since the photosensitive resin composition of the present invention is excellent in stress relaxation property, adhesiveness and the like, it can be used in a semiconductor element having a rewiring structure as shown in FIGS.

  FIG. 6 is a schematic cross-sectional view showing a wiring structure as one embodiment of a semiconductor element. A semiconductor element 600 shown in FIG. 6 includes a silicon substrate 23, an interlayer insulating layer 11 provided on one side of the silicon substrate 23, and an Al having a pattern including a pad portion 15 formed on the interlayer insulating layer 11. A wiring layer 12, an insulating layer 13 (for example, a P-SiN layer) and a surface protective layer 14, which are sequentially stacked on the interlayer insulating layer 11 and the Al wiring layer 12 while forming an opening on the pad portion 15, and a surface protective layer 14 in contact with the pad portion 15 in the openings of the insulating layer 13 and the surface protective layer 14 and the surface of the core 18 opposite to the surface protective layer 14. And a rewiring layer 16 extending on the surface protective layer 14. Further, the semiconductor device 600 is formed so as to cover the surface protective layer 14, the core 18, and the rewiring layer 16, and a cover coat layer 19 in which an opening is formed in a portion of the rewiring layer 16 on the core 18. The conductive ball 17 connected to the rewiring layer 16 with the barrier metal 20 interposed therebetween in the opening of the layer 19, the collar 21 that holds the conductive ball, and the cover coat layer 19 around the conductive ball 17 are provided. The underfill 22 is provided. The conductive ball 17 is used as an external connection terminal and is formed of solder, gold or the like. The underfill 22 is provided to relieve stress when the semiconductor element 600 is mounted.

  In the semiconductor element 700 of FIG. 7, an Al wiring layer (not shown) and an Al wiring layer pad portion 15 are formed on a silicon substrate 23, and an insulating layer 13 is formed on the Al wiring layer. A surface protective layer 14 is formed. A rewiring layer 16 is formed on the pad portion 15, and the rewiring layer 16 extends to an upper portion of the connection portion 24 with the conductive ball 17. Further, a cover coat layer 19 is formed on the surface protective layer 14. The rewiring layer 16 is connected to the conductive ball 17 through the barrier metal 20.

  6 and 7, the photosensitive resin composition is a material for forming not only the interlayer insulating layer 11 and the surface protective layer 14, but also the cover coat layer 19, the core 18, the collar 21, the underfill 22, and the like. Can be used as The pattern cured film using the photosensitive resin composition of the present invention has excellent adhesion to a metal layer such as the Al wiring layer 12 or the rewiring layer 16 or a sealing material, and has a high stress relaxation effect. A semiconductor element using a cured film as an interlayer insulating layer 11, a surface protective layer 14, a cover coat layer 19, a core 18, a collar 21 such as solder, an underfill 22 used in a flip chip or the like has extremely excellent reliability. It becomes.

  The photosensitive resin composition of the present invention is preferably used for the interlayer insulating layer 11, the surface protective layer 14 and / or the cover coat layer 19 of the semiconductor element having the rewiring layer 16 in FIGS.

  The film thicknesses of the interlayer insulating layer 11, the surface protective layer 14, and the cover coat layer 19 are preferably 3 to 20 μm, and more preferably 5 to 15 μm.

[Electronic device]
The electronic device of the present invention has the semiconductor element of the present invention. The electronic device includes the above-described semiconductor element, and examples thereof include a mobile phone, a smartphone, a tablet terminal, a personal computer, and a hard disk suspension.

  Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited thereto.

The materials used in this example are shown below.
[(A) component; bismaleimide compound]
A: BMI-3000 represented by the formula (IV)

[(B) component; photopolymerization initiator]
B1: (1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)]
B2: Ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime)

[Component (C); Silane Compound]
C1: 3-mercaptopropyltrimethoxysilane (trade name: KBM-803, manufactured by Shin-Etsu Chemical Co., Ltd.)
C2: N-phenyl-3-aminopropyltrimethoxysilane (trade name: KBM-573, manufactured by Shin-Etsu Chemical Co., Ltd.)
C3: Polymer type polyfunctional epoxy silane coupling agent (trade name: X-12-984S, manufactured by Shin-Etsu Chemical Co., Ltd.)
C4: 3-acryloxypropyltrimethoxysilane (trade name: KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.)

(Examples 1-3 and Comparative Examples 1-3)
Components (A) to (C) shown in Table 1 were mixed with 50 parts by mass of tetralin as a solvent, and photosensitive resin compositions of Examples 1 to 3 and Comparative Examples 1 to 3 were prepared.

<Evaluation of photosensitive resin composition>
About the photosensitive resin composition of Examples 1-3 and Comparative Examples 1-3, evaluation shown below was performed. The results are summarized in Table 1.

(Residual film rate, sensitivity, resolution)
The photosensitive resin compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were spin-coated on a silicon substrate and heated at 120 ° C. for 4 minutes to form a coating film having a thickness of 11 to 13 μm. Next, using an i-line stepper (trade name “FPA-3000iW” manufactured by Canon Inc.), i-line (365 nm) through a mask having a square hole pattern from 1 μm in length, 1 μm in width to 100 μm in length, and 100 μm in width. Reduced projection exposure. Exposure amount was carried out while changing to 100~1380mJ / cm ² by 20mJ / cm ^2. After the exposure, development was performed using cyclopentanone. Sensitivity was defined as the exposure amount at which the remaining film ratio began to become constant. The remaining film ratio was calculated by the following equation.

Residual film ratio (%) = (film thickness after development / film thickness before development) × 100

The remaining film rate in Table 1 is the remaining film rate with the sensitivity described in Table 1.
Further, the minimum opening width of the open square hole patterns was used as an index of resolution. The smaller the sensitivity and resolution, the better. The results are shown in Table 1.
Then, the resist pattern was heat-treated (cured) at a temperature of 200 ° C. (temperature increase time: 1.5 hours) in nitrogen using a vertical diffusion furnace (trade name “μ-TF” manufactured by Koyo Thermo System Co., Ltd.). )did.

(Adhesiveness after PCT)
The photosensitive resin compositions of Examples 1 to 3 and Comparative Examples 1 to 3 were spin coated on a silicon substrate and a copper plate, respectively, and heated at 120 ° C. for 4 minutes to form a resin film having a thickness of about 11 to 12 μm. did. This resin film was coated in a vertical diffusion furnace (manufactured by Koyo Thermo System Co., Ltd., trade name “μ-TF”) in nitrogen at a temperature of 180 ° C. (temperature increase time: 1.5 hours) for 2 hours. Was heat-treated (cured) to obtain a cured film having a thickness of about 10 μm. Thereafter, the obtained cured film together with the wafer was put into a pressure cooker tester manufactured by Hirayama Seisakusho, and placed under high temperature and high humidity conditions of 120 ° C., 2 atm and 100% RH, and taken out after 96 hours. The cured film was cut into 10 vertical and 10 horizontal grids with a razor using a cross cut guide (Cortech Co., Ltd.) to divide the cured film into 100 small pieces. After sticking an adhesive tape (made by Nichiban Co., Ltd.) there, it was peeled off. When peeling the adhesive tape, the adhesiveness was evaluated as follows depending on the presence or absence of small pieces peeled from the substrate.
○: No peeling △: No peeling of the mesh, but the cut end is peeling ×: There is peeling

  Comparative Example 1 has good adhesion to silicon and copper, but when the development is performed, the exposed portion of the coating film does not remain and a resist pattern cannot be obtained. Comparative Example 2 has good photosensitivity and good adhesion to copper, but has insufficient adhesion to silicon. Comparative Example 3 has good photosensitivity and no peeling of the cells, but it can be said that the notched end is peeled off and the adhesiveness is insufficient. On the other hand, the photosensitive resin compositions of Examples 1 to 3 containing C1 have good photosensitivity and high adhesion to both silicon and copper.

  DESCRIPTION OF SYMBOLS 1 ... Semiconductor substrate, 2 ... Protective film, 3 ... 1st conductor layer, 4 ... Interlayer insulation layer, 5 ... Photosensitive resin layer, 6A, 6B, 6C ... Window part, 7 ... 2nd conductor layer, 8 ... Surface protection 11 ... Interlayer insulating layer 12 ... Wiring layer 13 ... Insulating layer 14 ... Surface protective layer 15 ... Pad portion 16 ... Rewiring layer 17 ... Conductive ball 18 ... Core 19 ... Cover coat layer 20 ... barrier metal, 21 ... collar, 22 ... underfill, 23 ... silicon substrate, 24 ... connection part, 100, 200, 300, 400 ... structure, 500, 600, 700 ... semiconductor element.

Claims (6)

(A) a bismaleimide compound;
(B) a photopolymerization initiator;
(C) a silane compound containing a thiol group;
Containing a photosensitive resin composition.   Hardened | cured material of the photosensitive resin composition of Claim 1.   A step of applying and drying the photosensitive resin composition according to claim 1 on a part or the whole surface of a substrate to form a resin film, a step of exposing a part or the whole surface of the resin film, and a resin film after the exposure. The manufacturing method of a pattern cured film which has the process of developing and forming a pattern resin film, and the process of heating a pattern resin film.   The semiconductor element which has the hardened | cured material of Claim 2 as an interlayer insulation layer.   A semiconductor device having the cured product according to claim 2 as a surface protective layer.   An electronic device comprising the semiconductor element according to claim 4.

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