JP2022002304A - Laminate, curable resin composition, manufacturing method of laminate, semiconductor device, and imaging device - Google Patents

Abstract

To provide a laminate having high electrical connection reliability, a curable resin composition used for the laminate, a manufacturing method of the laminate, and an imaging device having the laminate.SOLUTION: A laminate includes a first substrate having an electrode, an organic film, and a second substrate having an electrode in this order, and the electrode of the first substrate and the electrode of the second substrate are electrically connected to each other through a through hole penetrating an organic film.SELECTED DRAWING: None

Description

The present invention relates to a laminate having high electrical connection reliability, a curable resin composition used for the laminate, a method for producing the laminate, and a semiconductor device and an image pickup apparatus having the laminate.

With the improvement of the performance of semiconductor devices, three-dimensionalization in which a plurality of semiconductor chips are laminated is progressing. In the manufacture of a laminate in which a plurality of semiconductor chips are laminated, first, a bonding surface in which a bonding electrode made of copper is surrounded by an insulating film is formed on the electrode surface of a substrate on which two electrodes are formed by a damascene method. Form. After that, two substrates are stacked so that the bonding electrodes on the bonding surface face each other, and heat treatment is performed to produce a laminated body (Patent Document 1).

Japanese Unexamined Patent Publication No. 2006-191081

In the production of the laminated body, a high temperature treatment of 400 ° C. for 4 hours is performed at the time of bonding the electrodes, so that the insulating film used for forming the bonded surface is required to have high heat resistance. Therefore, in the conventional laminated body, an insulating _{inorganic material such as SiN or SiO 2} is used as the insulator. However, the insulating film made of an inorganic material tends to warp the substrate, and if the substrate warps, the connection position of the electrodes may shift or the electrodes may crack when the laminated body is formed. Connection reliability may be low. Further, in recent years, the performance of semiconductor devices has been improved, and the size and thickness of the substrate have been increasing, so that the warp of the substrate is more likely to occur.

It is an object of the present invention to provide a laminate having high electrical connection reliability, a curable resin composition used for the laminate, a method for producing the laminate, and a semiconductor device and an image pickup apparatus having the laminate. And.

The present invention has a first substrate having electrodes, an organic film, and a second substrate having electrodes in this order, and the electrodes of the first substrate and the electrodes of the second substrate are , It is a laminated body electrically connected through a through hole penetrating the organic film. Hereinafter, the present invention will be described in detail.

The laminate of the present invention has a first substrate having electrodes, an organic film, and a second substrate having electrodes in this order, and the electrodes (first electrodes) of the first substrate and the above. The electrode (second electrode) of the second substrate is electrically connected via a through hole penetrating the organic film.
The organic film provided between the first electrode and the second electrode acts as an insulating layer, so that a short circuit of current can be suppressed. Since the conventional insulating layer uses a _{hard inorganic material such as SiN or SiO 2} , if warpage occurs during the formation of the insulating layer or the laminated body, this cannot be eliminated by stress relaxation, and as a result, it cannot be eliminated. The electrodes were prone to misalignment and cracking. In the present invention, by using an organic film having higher flexibility than an inorganic material as an insulating layer, high electrical connection reliability can be exhibited. In particular, since the warp can be eliminated even when the substrate or the laminated body is warped, even when a thin substrate on which the warp is likely to occur is laminated, the electrodes are less likely to be displaced or cracked and high electricity is generated. It is possible to obtain a laminated body having target connection reliability. Further, since the conventional insulating layer was formed by thin film deposition, it took a long time to form, but the organic film of the laminate of the present invention can be formed by applying and curing a curable resin, thereby increasing the production efficiency. be able to.
Here, electrically connected means a state in which the electrodes of the first substrate and the electrodes of the second substrate are connected by the conductive material or the like filled in the through holes.

The first substrate and the second substrate are not particularly limited, and a circuit board on which elements, wirings and electrodes are formed can be used. For example, a sensor circuit board provided with a pixel portion (pixel region), a circuit board on which peripheral circuit portions such as a logic circuit for executing various signal processes related to the operation of the solid-state image sensor are mounted can be used.

The electrode material and the conductive material of the first substrate and the second substrate are not particularly limited, and conventionally known electrode materials such as gold, copper, and aluminum can be used.

The organic film is not particularly limited as long as it is a layer containing an organic compound as a material, but a layer containing a resin as a material is preferable. The organic film may contain components other than the resin material as long as the effects of the present invention are not significantly impaired. In that case, the content of the resin material in the organic film is, for example, preferably 90% by weight or more, more preferably 95% by weight or more, still more preferably 99% by weight or more, and usually less than 100% by weight.
As the resin material, a polyimide resin or the like can be used.

The weight loss rate of the organic film after heat treatment at 400 ° C. for 4 hours is preferably 5% or less.
When the weight reduction rate of the organic film after heat treatment is within the above range, the substrates can be bonded more reliably, and bubbles and cracks at the interface and peeling at the interface due to the decomposed organic film can be suppressed. can. The weight reduction rate is more preferably 3% or less, and further preferably 1% or less. The lower limit of the weight reduction rate is not particularly limited, and the closer it is to 0%, the better, but the limit is about 0.5% in terms of manufacturing technology.
The weight loss rate after the heat treatment at 400 ° C. for 4 hours can be adjusted by adjusting the composition of the organic film, the type of resin material constituting the organic film, the curing conditions when producing the organic film, and the like.
Specifically, by adjusting the composition of the organic film, for example, by using a resin material or an inorganic component having high heat resistance, increasing the content of the cross-linking agent, etc., the weight reduction rate after the heat treatment at 400 ° C. for 4 hours can be determined. Can be reduced.
Further, the type of resin material constituting the organic film may be a resin having high heat resistance (for example, a resin having a large molecular weight, a resin having a main chain or a substituent having high heat resistance, a polyimide resin described later), or organic. By setting the curing conditions of the curable resin composition constituting the film to a high temperature at which curing proceeds sufficiently or by setting the curing time to a long time, the weight loss rate after the heat treatment at 400 ° C. for 4 hours is achieved. Can be reduced.

The surface hardness of the organic film measured by a nanoindenter is preferably 5 GPa or less.
Since the organic film having a surface hardness in the above range has high flexibility, it becomes more difficult for the substrate or the laminate to warp, and even if the warp occurs, it becomes easier to eliminate the warp. It is possible to further suppress misalignment and cracking.
The surface hardness is more preferably 5 GPa or less, further preferably 3 GPa or less, and even more preferably 1 GPa or less.
The lower limit of the surface hardness is not particularly limited, but is, for example, 0.1 GPa or 0.2 GPa, preferably 0.3 GPa.
The surface hardness measured by the nano-indenter of the organic film can be adjusted by the type of the resin component constituting the organic film and the composition of the organic film. Specifically, for example, a compound having a rigid skeleton having a low glass transition point or a polyimide resin described later, which can be increased by introducing a rigid skeleton having a high glass transition point or adding an inorganic filler, can be used. It can be reduced by using it.
Here, the nano indenter is a device that measures the hardness from the relationship between the force applied when the needle is pierced on the surface of the sample and the stress, and can measure the hardness of the surface layer of the sample. The hardness of the surface can be measured by, for example, the following method. First, the side surface (laminated surface) of the laminated body is embedded with cold resin and ground by a cross-section grinding device until the organic film is exposed. Then, using a nanoindenter (TI 950 TriboIndenter, manufactured by Cientaomicron, or an equivalent product thereof), the sample is pushed in at a rate of 200 nm / sec for a measurement displacement of 1000 nm, and then the measurement probe is pulled out at a rate of 200 nm / sec. It can be obtained by making measurements. A Berkovich type diamond indenter is used as the measurement probe.

The thickness of the organic film is not particularly limited, but is preferably 10 μm or more and 300 μm or less.
When the thickness of the organic film is within the above range, the function as an insulating layer can be more exhibited, and the displacement and cracking of the electrodes can be further suppressed. The thickness of the organic film is more preferably 20 μm or more, further preferably 30 μm or more, further preferably 200 μm or less, still more preferably 100 μm or less.

The organic film preferably contains a polyimide resin, and preferably contains a compound having the structure of the following general formula (1).
By using a compound having such a structure, it is possible to further suppress the displacement and cracking of the electrodes. Among them, since the displacement and cracking of the electrodes can be further suppressed, it is more preferable to have a functional group having a fluorine element in at least one ^{of P 1} or Q ^{1 of the following general formula (1), and both have a fluorine element.} It is more preferable to have a functional group.

ここで、Ｐ^１は脂環式基又は芳香族基を表す。Ｑ^１は直鎖状、分岐鎖状若しくは環状の脂肪族基又は芳香族基を表す。上記脂肪族基及び上記芳香族基は置換基を有していても有していなくてもよい。Ｓ１は１以上の自然数を表す。

Here, P ¹ represents an alicyclic group or an aromatic group. Q ¹ represents a linear, branched or cyclic aliphatic group or an aromatic group. The aliphatic group and the aromatic group may or may not have a substituent. S1 represents a natural number of 1 or more.

In the above general formula (1), P ¹ represents an alicyclic group or an aromatic group. The P ¹ is preferably an aromatic group having 5 to 50 carbon atoms, and more preferably an aromatic group derived from a bisphenol skeleton. Since P ¹ is an aromatic group having 5 to 50 carbon atoms, particularly high heat resistance can be exhibited.

The general formula (1) was Q ¹ represents a linear, branched or cyclic aliphatic group or an aromatic group. The aliphatic group and the aromatic group may or may not have a substituent. The Q ¹ represents a substituted or unsubstituted, straight, preferably a branched or cyclic aliphatic group having 2 to 100 carbon atoms, more preferably an aromatic group derived from a bisphenol skeleton.

In the above general formula (1), S1 is a natural number of 1 or more and represents the number of repeating units. The above S1 is preferably 10 or more, more preferably 50 or more, and preferably 100 or less.

The functional group having a fluorine element is not particularly limited, and examples thereof include a fluoro group and a fluoroalkyl group in which a part or all of hydrogen atoms of an alkyl group are fluorinated.

The compound having the structure of the general formula (1) preferably contains 5% by weight or more and 35% by weight or less of the fluorine element.
When the compound having the structure of the general formula (1) contains an element of fluorine in an amount in the above range, the heat resistance of the organic film is improved, and the displacement and cracking of the electrodes can be further suppressed. The content of the fluorine element is more preferably 10% by weight or more, further preferably 15% by weight or more, further preferably 30% by weight or less, and further preferably 25% by weight or less. preferable.

The organic film preferably contains a compound having a novolak-type structure.
Since the organic film has a novolak type structure, it is possible to further suppress the displacement and cracking of the electrodes. Examples of the organic film having a novolak-type structure include those obtained by curing a compound having a benzoxazine structure, which will be described later.

The organic film is preferably a cured product of a curable resin composition.
By using the curable resin composition as the material of the organic film, the organic film can be formed by coating and curing, so that the production efficiency can be improved as compared with the case of using the conventional inorganic material. The curable resin constituting the curable resin composition may be thermosetting or photocurable, but is preferably a thermosetting resin from the viewpoint of heat resistance.

The curable resin composition preferably contains a polyimide resin.
The content of the polyimide resin is preferably 80 parts by weight or more, more preferably 90 parts by weight or more, still more preferably 95 parts by weight or more in 100 parts by weight of the resin solid content in the curable resin composition. The content of the organosilicon compound having the reactive moiety is preferably less than 100 parts by weight, more preferably 99.5 parts by weight or less, still more preferably, in 100 parts by weight of the resin solid content in the curable resin composition. Is 99 parts by weight or less.

The polyimide resin is more preferably a resin having the structure of the following general formula (1).
That is, it is more preferable that the curable resin composition contains a curable resin having the structure of the following general formula (1).
By using a compound having such a structure, it is possible to further suppress the displacement and cracking of the electrodes. Among them, since the displacement and cracking of the electrodes can be further suppressed, it is more preferable to have a functional group having a fluorine element in at least one ^{of P 1} or Q ^{1 of the following general formula (1), and both have a fluorine element.} It is more preferable to have a functional group.

ここで、Ｐ^１は脂環式基又は芳香族基を表す。Ｑ^１は直鎖状、分岐鎖状若しくは環状の脂肪族基又は芳香族基を表す。上記脂肪族基及び上記芳香族基は置換基を有していても有していなくてもよい。Ｓ１は１以上の自然数を表す。

Here, P ¹ represents an alicyclic group or an aromatic group. Q ¹ represents a linear, branched or cyclic aliphatic group or an aromatic group. The aliphatic group and the aromatic group may or may not have a substituent. S1 represents a natural number of 1 or more.

In the above general formula (1), P ¹ represents an alicyclic group or an aromatic group. The P ¹ is preferably an aromatic group having 5 to 50 carbon atoms, and more preferably an aromatic group derived from a bisphenol skeleton. Since P ¹ is an aromatic group having 5 to 50 carbon atoms, particularly high heat resistance can be exhibited.

The general formula (1) was Q ¹ represents a linear, branched or cyclic aliphatic group or an aromatic group. The aliphatic group and the aromatic group may or may not have a substituent. The Q ¹ represents a substituted or unsubstituted, straight, preferably a branched or cyclic aliphatic group having 2 to 100 carbon atoms, more preferably an aromatic group derived from a bisphenol skeleton.

In the above general formula (1), S1 is a natural number of 1 or more and represents the number of repeating units. The above S1 is preferably 10 or more, more preferably 50 or more, and preferably 100 or less.

The functional group having a fluorine element is not particularly limited, and examples thereof include a fluoro group and a fluoroalkyl group in which a part or all of hydrogen atoms of an alkyl group are fluorinated.

The compound having the structure of the general formula (1) preferably contains 5% by weight or more and 35% by weight or less of the fluorine element.
When the compound having the structure of the general formula (1) contains an element of fluorine in the above range, the heat resistance of the cured product (organic film) of the curable resin composition is improved, and the electrode is more easily displaced or cracked. It can be suppressed. The content of the fluorine element is more preferably 10% by weight or more, further preferably 15% by weight or more, further preferably 30% by weight or less, and further preferably 25% by weight or less. preferable.

The curable resin preferably has a benzoxazine structure. By using a compound having a benzoxazine structure as the curable resin constituting the curable resin composition, it is possible to further suppress the displacement and cracking of the electrodes. Further, since the compound having benzoxazine has excellent heat resistance, it is possible to further suppress the decomposition of the organic film due to the high temperature treatment performed at the time of manufacturing the laminate or the electronic component using the laminate. The benzoxazine structure is preferably held at the end of the molecule.

The curable resin composition preferably has a tensile elastic modulus of 5 GPa or less at 25 ° C. of the cured product. When the tensile elastic modulus is within the above range, the flexibility is further increased, so that the occurrence of warpage of the substrate and the laminated body can be further suppressed, and the displacement and cracking of the electrodes can be further suppressed. The tensile elastic modulus is more preferably 4.5 GPa or less, and further preferably 4 GPa or less. The lower limit of the tensile elastic modulus is not particularly limited, but is preferably 100 MPa or more from the viewpoint of reliably connecting the substrates. The tensile elastic modulus can be measured by a dynamic viscoelasticity measuring device (for example, DVA-200 manufactured by IT Measurement Control Co., Ltd.). More specifically, when the curable resin composition is thermosetting, the curable resin composition is dried by heating at 120 ° C. for 1 hour, and further heated at 200 ° C. for 1 hour to cure the curable resin composition. The measurement is performed under the conditions of a constant speed temperature rise tension mode, a temperature rise rate of 10 ° C./min, and a frequency of 10 Hz. When the curable resin composition is photocurable, it is dried by a solvent by heating at 120 ° C. for 1 hour, ^{irradiated with UV of 405 nm at 3000 mJ / cm 2} to cure the curable resin composition, and then heated. It can be measured under the same measurement conditions as the curable resin composition.
The tensile elastic modulus at 25 ° C. can be adjusted by the composition of the curable resin composition and the type of the curable resin.
Specifically, for example, a compound having a rigid skeleton having a low glass transition point and a compound having a rigid skeleton having a low glass transition point, which can increase the tensile elastic modulus by introducing a rigid skeleton having a high glass transition point or adding an inorganic filler, or the above. The tensile elastic modulus can be reduced by using a polyimide resin or the like.

The weight average molecular weight of the curable resin is not particularly limited, but is preferably 5000 or more and 150,000 or less. When the molecular weight of the curable resin is within the above range, the film-forming property at the time of coating is improved, and the displacement and cracking of the electrodes can be further suppressed. The molecular weight of the curable resin is more preferably 10,000 or more, further preferably 30,000 or more, further preferably 100,000 or less, and further preferably 70,000 or less.
The weight average molecular weight of the curable resin is measured as a polystyrene-equivalent molecular weight by a gel permeation chromatography (GPC) method. It can be calculated by the polystyrene standard using THF as the elution solvent and HR-MB-M6.0 × 150 mm (manufactured by Waters) or an equivalent product thereof as the column.

The compound having the structure of the general formula (1) can be obtained, for example, by reacting a diamine compound with an aromatic acid anhydride to prepare an imide compound. Further, when it has a benzoxazine structure, it can be obtained by reacting the amine functional group of the imide compound with phenol and formaldehyde.

As the diamine compound, either an aliphatic diamine compound or an aromatic diamine compound can be used.
Among them, as the diamine compound, it is preferable to use a diamine compound having a functional group having a fluorine element. By using the diamine compound having a functional group having a fluorine element, it is possible to produce a compound having a structure represented by the general formula (1) having a functional group having a fluorine element Q ^1.

Examples of the aliphatic diamine compound include 1,10-diaminodecane, 1,12-diaminododecane, dimerdiamine, 1,2-diamino-2-methylpropane, 1,2-diaminocyclohexane, and 1,2-diamino. Propane, 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, 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 and the like can be mentioned.

Examples of the aromatic diamine compound include 9,10-diaminophenanthrene, 4,4'-diaminooctafluorobiphenyl, 3,7-diamino-2-methoxyfluorene, 4,4'-diaminobenzophenone, and 3,4-. Diaminobenzophenone, 3,4-diaminotoluene, 2,6-diaminoanthraquinone, 2,6-diaminotoluene, 2,3-diaminotoluene, 1,8-diaminonaphthalene, 2,4-diaminotoluene, 2,5-diamino Toluene, 1,4-diaminoanthraquinone, 1,5-diaminoanthraquinone, 1,5-diaminonaphthalene, 1,2-diaminoanthraquinone, 2,4-kumendiamine, 1,3-bisaminomethylbenzene, 1,3- Bisaminomethylcyclohexane, 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-chlorophenyl) ethane, bis (4-amino-3,5-dimethylphenyl) methane, bis (4-amino-3,5-diethylphenyl) methane, bis (4-Amino-3-ethyldiaminofluorene, 2,3-diaminonaphthalene, 2,3-diaminophenol, bis (4-amino-3-methylphenyl) methane, bis (4-amino-3-ethylphenyl) methane , 4,4'-Diaminophenyl sulfone, 3,3'-diaminophenyl sulfone, 2,2-bis (4, (4 aminophenoxy) phenyl) sulfone, 2,2-bis (4- (3-aminophenoxy)) Phenyl) sulfone, 4,4'-oxydianiline, 4,4'-diaminodiphenylsulfide, 3,4'-oxydianiline, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 1, , 3-Bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, 4,4'-diamino-3,3'-dimethylbiphenyl, 4,4'-diamino-3, 3'-Dimethoxybiphenyl, Bisanyline M, Bisanyline P, 9,9-bis (4-aminophenyl) fluorene, o-trizine sulfone, methylenebis (anthranyl acid), 1,3-bis (4-aminophenoxy) -2, 2-Dimethylpropane, 1,3-bis (4-aminophenoxy) propane, 1,4-bis (4-Aminophenoxy) Butane, 1,5-bis (4-Aminophenoxy) Butane, 2,3,5,6-Tetramethyl-1,4-phenylenediamine, 3,3', 5,5'-Tetra Methylbenzidine, 4,4'-diaminobenzanilide, 2,2-bis (4-aminophenyl) hexafluoropropane, polyoxyalkylene diamines (eg, Huntsman's Jeffamine D-230, D400, D-2000 and D). -4000), 1,3-cyclohexanebis (methylamine), m-xylylenediamine, p-xylylenediamine and the like.

Examples of the diamine compound having a functional group having a fluorine element include 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, and the like. Examples thereof include 2,2-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane.

Examples of the aromatic acid anhydride include pyromellitic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,4,5-naphthalene. Tetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 3,3', 4,4'-benzophenonetetracarboxylic acid, 3,3', 4,4'-biphenyl ether tetracarboxylic acid, 3, 3', 4,4'-biphenyltetracarboxylic acid, 2,3,5,6-pyridinetetracarboxylic acid, 3,4,9,10-perylenetetracarboxylic acid, 4,4'-sulfonyldiphthalic acid, 1 -Trifluoromethyl-2,3,5,6-benzenetetracarboxylic acid, 2,2', 3,3'-biphenyltetracarboxylic acid, 2,2-bis (3,4-dicarboxyphenyl) propane, 2 , 2-bis (2,3-dicarboxyphenyl) propane, 1,1-bis (2,3-dicarboxyphenyl) ethane, 1,1-bis (3,4-dicarboxyphenyl) ethane, bis (2) , 3-Dicarboxyphenyl) methane, bis (3,4-dicarboxyphenyl) methane, bis (3,4-dicarboxyphenyl) sulfone, bis (3,4-dicarboxyphenyl) ether, benzene-1,2 , 3,4-Tetracarboxylic acid, 2,3,2', 3'-benzophenone tetracarboxylic acid, 2,3,3', 4'-benzophenone tetracarboxylic acid, phenanthrene-1,8,9,10-tetra Carboxylic acid, pyrazine-2,3,5,6-tetracarboxylic acid, thiophen-2,3,4,5-tetracarboxylic acid, 2,3,3', 4'-biphenyltetracarboxylic acid, 3,4 3', 4'-biphenyltetracarboxylic acid, 2,3,2', 3'-biphenyltetracarboxylic acid, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfide, 4,4'-( 4,4'-isopropylidene diphenoxy) -bis (phthalic acid) and the like can be mentioned.

As the aromatic acid anhydride, it is preferable to use a compound having a functional group having a fluorine element. By using a compound having a functional group having a fluorine element, a compound having a structure represented by the above general formula (1) having a functional group having a fluorine element in ^{P 1 can be produced.}
Examples of the aromatic acid anhydride having a functional group having a fluorine element include 4,4'-(hexafluoroisopropylidene) diphthalic acid anhydride.

As a method for producing a compound having the structure represented by the general formula (1) having the benzoxazine structure at the end of the molecule, for example, under the condition that the diamine compound is excessive, aromatic acid anhydride and diamine are used. Examples thereof include a method of reacting a compound to produce an imide compound having amino groups at both ends, and reacting an excess amount of the phenol compound with formaldehyde on the terminal amino groups.
Examples of the phenol compound include phenol, p-cresol, o-cresol, m-cresol, p-ethylphenol, o-ethylphenol, m-ethylphenol, pn-propylphenol, on-propylphenol, and m. -N-propylphenol, p-iso-propylphenol, o-iso-propylphenol, m-iso-propylphenol, pn-butylphenol, on-butylphenol, mn-butylphenol, p-sec-butylphenol , O-sec-butylphenol, m-sec-butylphenol, p-iso-butylphenol, o-iso-butylphenol, m-iso-butylphenol, p-tert-butylphenol, o-tert-butylphenol, m-tert-butylphenol, etc. Can be mentioned.

The curable resin composition may contain a catalyst that promotes a curing reaction.
By having the catalyst in the organic film, the curable resin composition can be cured more completely, and the decomposition of the organic film due to the high temperature treatment can be further suppressed.
Examples of the catalyst include acid catalysts such as phenol and carboxylic acid, and base catalysts such as amine and imidazole. Of these, an acid catalyst is preferable because it can accelerate the curing of the curable resin composition. The catalyst is present even after the curable resin composition has been cured. That is, it is preferable that the organic film contains a catalyst that promotes the curing reaction.

The content of the catalyst is not particularly limited, but is preferably 0.01 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the curable resin in the curable resin composition. By setting the content of the catalyst in the above range, the curing of the curable resin composition can be further promoted. The content of the catalyst is more preferably 0.05 parts by weight or more, further preferably 0.1 parts by weight or more, still more preferably 5 parts by weight or less, and more preferably 1 part by weight or less. Is even more preferable.

The curable resin composition may contain a silane coupling agent.
By containing the silane coupling agent, the adhesion to the substrate and the inorganic film described later can be further improved, and the conduction failure and the deterioration of reliability due to the voids generated by the adhesion failure can be further suppressed.

The content of the silane coupling agent is not particularly limited, but is preferably 0.01 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the curable resin in the curable resin composition. By setting the content of the silane coupling agent in the above range, the adhesion to the substrate and the inorganic film described later can be suitably exhibited. The content of the silane coupling agent is more preferably 0.1 parts by weight or more, further preferably 0.5 parts by weight or more, still more preferably 5 parts by weight or less, and 1 part by weight. The following is more preferable.

The curable resin composition may contain other additives such as a viscosity modifier and a filler, if necessary.

The laminate of the present invention can be made into a laminate having high electrical connection reliability by curing the curable resin composition to form the organic film.
Such a first substrate having an electrode, an organic film, and a second substrate having an electrode are provided in this order, and the first electrode and the second electrode penetrate the organic film. A curable resin composition used for the organic film of a laminate electrically connected through a through hole is also one of the present inventions.

The laminate of the present invention preferably has an inorganic layer having a thickness of 1 nm or more and 1 μm or less between the first substrate and the second substrate.
By providing an inorganic layer between the first substrate and the second substrate, it is possible to obtain a laminated body having improved insulation and higher connection reliability. Since the conventional laminated body has an insulating layer made of an inorganic material having a thickness of about 10 to 20 μm, the warp of the substrate and the laminated body cannot be eliminated, which causes a decrease in connection reliability. Since the inorganic layer in one embodiment has an extremely thin thickness of 1 μm or less, warpage generated in the substrate and the laminated body can be eliminated even when the inorganic layer is provided.

The material of the inorganic layer is not particularly limited, and examples thereof include SiN, SiO ₂ , Al ₂ O _{3, and the} like. _{Of these, SiN and SiO 2} are preferable because they are excellent in insulation and heat resistance.

The thickness of the inorganic layer is more preferably 5 nm or more, further preferably 10 nm or more, further preferably 500 nm or less, and more preferably 100 nm or less from the viewpoint of further enhancing the connection reliability of the laminated body. Is more preferable.

The laminate of the present invention preferably has a barrier metal layer on the surface of the through holes.
The barrier metal layer has a role of preventing diffusion of the conductive material (for example, Cu atom in the case of a Cu electrode) filled in the through hole into the organic film. By providing a barrier metal layer on the surface of the through hole, the conductive material that fills the through hole is covered with the barrier metal layer except for the surface in contact with the electrode. It can be suppressed. As the material of the barrier metal layer, known materials such as tantalum, tantalum nitride, and titanium nitride can be used.

The thickness of the barrier metal layer is not particularly limited, but is more preferably 1 nm or more, further preferably 10 nm or more, still more preferably 100 nm or less, from the viewpoint of further enhancing the connection reliability of the laminated body. It is more preferably 50 nm or less.

Here, FIG. 1 shows a diagram schematically showing one aspect of the laminated body of the present invention. As shown in FIG. 1, in the laminate of the present invention, the first substrate 1 having the electrodes 3 and the second substrate 2 are adhered to each other via the organic film 4, and the first substrate 1 and the second substrate 2 are bonded to each other. The electrode 3 on the substrate 2 has a structure in which the electrode 3 is electrically connected through a conductive material filled in the through hole 5 provided in the organic film 4. In the conventional laminate, the portion of the organic film 4 that hits the insulating layer is a hard inorganic material, so if warpage occurs in the substrate or laminate, it cannot be eliminated by stress relaxation, and the electrodes are likely to shift or crack. It was. In the present invention, by using a flexible organic compound for the insulating layer, the warp of the substrate or the laminated body can be eliminated, so that the displacement or cracking of the electrodes can be suppressed.

FIG. 2 shows a diagram schematically showing one aspect of the laminated body of the present invention. In the aspect of FIG. 2, the inorganic layer 6 is provided between the organic films 4 to further enhance the insulating property. The inorganic layer 6 of the present invention has a thickness of 1 nm to 1 μm and is thinner than the insulating layer of the conventional laminated body, so that it does not hinder the warping of the substrate or the laminated body. Further, although the inorganic layer 6 is provided between the organic films 4 in FIG. 2, it may be provided on the first substrate 1 and the second substrate 2. Further, in FIG. 2, the inorganic layer 6 is provided on the organic film 4 on the first substrate 1 side and the second substrate 2 side, respectively, but it may be provided on only one of them. Further, in the aspect of FIG. 2, the barrier metal layer 7 is provided on the surface of the through hole 5. By forming the barrier metal layer 7 on the surface of the through hole 5, the conductive material filled in the through hole 5 is less likely to diffuse into the organic film 4, so that short circuits and poor continuity can be further suppressed.

As a method for producing the laminate of the present invention, for example,
A step of forming an organic film on a surface of a first substrate having an electrode on which an electrode is formed, a step of forming a through hole in the organic film, a step of filling the through hole with a conductive material, and the above-mentioned step. The steps of polishing the surface of the substrate on the side filled with the conductive material to form a bonded electrode, the first substrate on which the bonded electrode is formed, and the second substrate on which the bonded electrode is formed are described. Examples thereof include a manufacturing method including a step of bonding the bonded electrodes so that they are bonded to each other. A method for producing such a laminate is also one of the present inventions.

In the method for producing a laminate of the present invention, first, a step of forming an organic film on a surface of a substrate having an electrode on which an electrode is formed is performed.
As the substrate having the electrodes and the organic film, the same as the substrate having the electrodes of the laminate of the present invention and the organic film of the present invention can be used.

The method for forming the organic film preferably includes a step of applying the curable resin composition and then curing the curable resin composition in addition to solvent drying. As the curable resin composition, the same curable resin composition as that of the present invention can be used. The coating method is not particularly limited, and a conventionally known method such as a spin coating method can be used.
The solvent drying conditions are not particularly limited, but are preferably 100 ° C. or higher, more preferably 150 ° C. or higher, preferably 250 ° C. or lower, more preferably 200 ° C. or lower, from the viewpoint of reducing residual solvent and improving the heat resistance of the organic film. It is preferable to heat at a temperature, for example, about 1 hour.
The conditions of the curing step are not particularly limited, but from the viewpoint of sufficiently advancing the curing reaction of the curable resin composition and further improving the heat resistance, when the curable resin composition is a thermosetting resin, it is preferably 200. It is preferable to heat at a temperature of ° C. or higher, more preferably 250 ° C. or higher, preferably 400 ° C. or lower, more preferably 300 ° C. or lower, for example, 30 minutes or longer, more preferably 1 hour or longer. The upper limit of the heating time is not particularly limited, but is preferably 2 hours or less from the viewpoint of suppressing thermal decomposition of the organic film. When the curable resin composition is a photocurable resin, a 405nm ultraviolet light preferably 1500 mJ / cm ² or more, more preferably it is preferred to irradiate 3000 mJ / cm ² or more.

In the method for producing a laminate of the present invention, a step of forming through holes in the organic film is then performed.
The through holes may be patterned. The method for forming the through hole is not particularly limited, and the through hole can be formed by laser irradiation such as _{a CO 2 laser or etching.} When another layer is formed on the electrode surface of the substrate, the through hole is formed so as to penetrate the other layer and expose the electrode surface of the substrate.

In the method for producing a laminate of the present invention, a step of forming an inorganic layer and / or a barrier metal layer is then performed, if necessary.
As the inorganic layer and the barrier metal layer, the same ones as the laminated body of the present invention can be used. The inorganic layer and the barrier metal layer can be formed by sputtering, vapor deposition, or the like.
The step of forming the inorganic layer is preferably performed before and / or after the step of forming the organic film. The formation of the barrier metal layer is preferably performed after the step of forming the through holes.

In the method for producing a laminated body of the present invention, a step of filling the through holes with a conductive material is then performed.
As the conductive material, the same conductive material as the laminated body of the present invention can be used.

In the method for manufacturing a laminate of the present invention, a step of polishing the surface of the substrate on the side filled with the conductive material to form a bonded electrode is then performed.
By removing the conductive material formed in the unnecessary portion by grinding, a bonded electrode connecting the electrodes formed on the two substrates is formed. The polishing preferably flattens and removes the layer formed of the conductive material until the organic film is exposed or, if any, the inorganic layer is exposed. The polishing method is not particularly limited, and for example, a chemical mechanical polishing method or the like can be used.

The method for manufacturing a laminated body of the present invention is a step of bonding the first substrate on which the junction electrode is formed and the second substrate on which the junction electrode is formed so that the junction electrodes are bonded to each other. Do the process.
Examples of the method of bonding the first substrate and the second substrate together include a method of melting and connecting the electrodes and the connecting electrodes by heat treatment. The heat treatment is usually about 400 ° C. for 4 hours.

The application of the laminate of the present invention is not particularly limited, but it has high electrical connection reliability, and warpage of the substrate or laminate can be suppressed even when thin substrates are bonded to each other. It can be suitably used for a laminated body constituting an image pickup device.
A semiconductor device and an image pickup device having such a laminated body of the present invention are also one of the present inventions.

According to the present invention, there are provided a laminate having high electrical connection reliability, a curable resin composition used for the laminate, a method for producing the laminate, and a semiconductor device and an image pickup apparatus having the laminate. Can be done.

It is a figure which represented one aspect of the laminated body of this invention schematically. It is a figure which represented one aspect of the laminated body of this invention schematically.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Manufacturing of curable resin)
(1) Production of Benzoxazine Resin-A Tetracarboxylic acid dianhydride 4,4'-(Hexafluoroisopropylide) diphthalic anhydride (Tokyo Kasei Co., Ltd.) in a reaction vessel equipped with a stirrer, water divider, thermometer and nitrogen gas introduction group. Co., Ltd., molecular weight 444.24) 120.0 g and 400 g of toluene were added, and the solution in the reaction vessel was heated to 60 ° C. Then, 207.3 g of aromatic diamine 2,2-Bis [4- (4-aminophenoxy) phenyl] hexafluoropropane (manufactured by Tokyo Kasei Co., Ltd., molecular weight 518.46) was added to the reaction vessel. A Dean-Stark trap and a condenser were attached to the flask, and the mixture was heated to reflux for 2 hours to obtain an imide compound having amines at both ends. Then, an excess amount of phenol and paraformaldehyde was added to the reaction solution, and the obtained mixture was refluxed for another 12 hours to carry out terminal benzoxazine formation. After completion of the reaction, isopropanol was added and reprecipitated, and then the precipitate was collected and dried. In this way, a compound having a benzoxazine structure having a structure of the following formula (2) having an imide skeleton and a benzoxazine structure at the terminal (benzoxazine resin-A, weight average molecular weight 50,000) was obtained.

(2) Production of Benzoxazine Resin-B Resin A is produced in the same manner as for Benzoxazine Resin-A, except that the time for reflux after adding tetracarboxylic acid dianhydride and aromatic diamine is set to 6 hours. A compound having the same structure as that of the above and having a different molecular weight (benzoxazine resin-B, weight average molecular weight of 100,000) was obtained.

(3) Production of Benzoxazine Resin-C Resin A is produced in the same manner as for Benzoxazine Resin-A, except that the time for reflux after adding tetracarboxylic acid dianhydride and aromatic diamine is set to 1 hour. A compound having the same structure as that of the above and having a different molecular weight (benzoxazine resin-C, weight average molecular weight of 30,000) was obtained.

(4) Production of Benzoxazine Resin-D As an aromatic diamine, 2,2-Bis (4-aminophenyl) hexafluoropropane (manufactured by Tokyo Kasei Co., Ltd., molecular weight 334.27) was used, and the addition amount was 133.7 g. Other than that, synthesis was carried out in the same manner as in the production of BMI resin-A to obtain a compound having a benzoxazine structure having the structure of the following formula (3) (benzoxazine resin-D, weight average molecular weight 40,000).

(5) Production of Benzoxazine Resin-E 4,4'-(4,4'-isopropyridenediphenoxy) diphthalic acid anhydride instead of tetracarboxylic acid dianhydride (manufactured by Tokyo Kasei Co., Ltd., molecular weight 520.49) 140.5 g was used, and 164.2 g of 2,2-bis [4- (4-aminophenoxy) phenyl] propane (manufactured by Tokyo Kasei Co., Ltd., molecular weight 410.52) was used instead of the aromatic diamine. A compound having a benzoxazine structure having the structure of the following formula (4) (benzoxazine resin-E, weight average molecular weight of 50,000) was obtained by the same method as in the production of BMI resin-A except for the above.

(6) Polyimide resin Iupia-AT manufactured by Ube Industries, Ltd. was used as the polyimide resin.

(7) Manufacture of Wafer 1 A film was formed on a 12 inch silicon wafer in the order of SiO: 500 nm, SiCN: 50 nm, and SiO: 250 nm by plasma CVD. A 250 nm SiO layer on the surface was etched using a photomask, and then Ta was formed at 50 nm as a barrier metal layer, and TaN was formed at 10 nm on the TaN. Then, Cu plating was performed and flattened by CMP. A SiCN layer (50 nm) and a SiO layer (500 nm) were sequentially deposited on the electrode pattern by plasma CVD to obtain a wafer 1 having an electrode.
(8) Manufacture of Wafer 2 The wafer 2 was manufactured in the same manner as the wafer 1 except that the opposite connection electrodes and the electrodes formed on the wafer were patterned so as to form a daisy chain when bonded.

(Example 1)
100 parts by weight of the obtained benzoxazine resin-A and 0.5 part by weight of a silane coupling agent (KBM573, manufactured by Shin-Etsu Chemical Co., Ltd.) are dissolved in propylene glycol monoethyl acetate and mixed to adjust the solid content to 25%. As a result, a curable resin composition solution was obtained.
Next, the curable resin composition solution obtained on the surface of the wafer 1 on which the electrodes were formed was coated with a spin coater, heated at 90 ° C. for 30 minutes to dry the solvent, and further heated at 200 ° C. for 1 hour. , An organic film having a thickness of 20 μm was formed on the electrode surface of the wafer 1. Then, a SiN layer having a thickness of 500 nm was formed by plasma CVD. Next, a through hole was formed on the electrode of the wafer 1 by etching the SiN layer and the organic film and the SiO layer and the SiCN layer existing on the electrode surface of the wafer 1 using a photomask. At this time, the diameter of the via to be etched was set to 20 μm, and the pitch with the adjacent via was set to 40 μm. Then, Ta was formed at 50 nm as a barrier metal layer, and TaN was further formed at 10 nm on the layer, and then Cu plating was performed to fill the through holes with a conductive material. Next, an unnecessary conductive material was removed by grinding the Cu-plated side surface of the wafer 1 (the surface on the side where the organic film of the wafer 1 was laminated) to form a connection electrode.
On the other hand, an organic film and connection electrodes are formed on the wafer 2 in the same manner as the wafer 1, except that the connecting electrodes facing each other and the electrodes formed on the wafer are patterned so that a daisy chain can be formed when they are bonded together. did.
Then, after the wafer 1 and the wafer 2 H ₂ plasma cleaning, bonding two substrates in vacuum to connection electrodes overlap each other to obtain a laminated body by heat treatment of 400 ° C. 4 h.

(Examples 2 to 9)
A laminate was obtained in the same manner as in Example 1 except that the types of the curable resin and the blending amount of the silane coupling agent were as shown in Table 1.
As the silane coupling agent, KBM573 manufactured by Shin-Etsu Chemical Co., Ltd. was used.

(Example 10)
A laminate was obtained in the same manner as in Example 1 except that a SiN layer having a thickness of 500 nm was not formed after the formation of the organic film.

(Comparative Example 1)
Plasma CVD was applied to the surface of the wafer 1 on which the electrodes were formed to form an inorganic layer made _{of Si 3} N _{4 having a thickness of 20 μm.} A laminate was obtained in the same manner as in Example 1 except that the inorganic layer was used as a substitute for the organic film. The detailed conditions for plasma CVD are as follows.
Raw material gas: SiH ₄ gas and nitrogen gas flow rate: SiH ₄ gas 10 sccm, nitrogen gas 200 sccm
RF power: 10W (frequency 2.45GHz)
Chamber temperature: 100 ° C
Chamber pressure: 0.9 Torr

(Comparative Example 2)
Using SiH ₄ gas and oxygen gas as raw material gases, except for forming an inorganic layer made of SiO ₂ having a thickness of 20μm by changing the plasma CVD target SiO ₂ was obtained a laminate in the same manner as in Comparative Example 1.

(Measurement of weight loss)
A monolayer of an organic film and an inorganic layer was prepared by the above method, respectively. Using a differential thermal weight simultaneous measuring device (TG-DTA; STA7200, manufactured by Hitachi High-Tech Science Co., Ltd.) for the obtained single layer, 25 at a heating rate of 10 ° C./min under a nitrogen flow at 50 mL / min. The weight loss rate was measured when the mixture was heated from ° C. to 400 ° C. and held at 400 ° C. for 4 hours. The results are shown in Table 1.

(Measurement of surface hardness)
The side surface of the obtained laminate was embedded in cold resin and ground to expose the organic film or the inorganic layer on the side surface. Then, using a nanoindenter (TI 950 TriboIndenter, manufactured by Cientaomicron), the sample is pushed in at a speed of 200 nm / sec for a measurement displacement of 1000 nm, and then the measurement is performed under the condition that the measurement probe is pulled out at a speed of 200 nm / sec. An indent curve of an organic film or an inorganic layer was obtained. A Berkovich type diamond indenter was used as the measurement probe. The surface hardness was measured by calculating the surface nanoindentation hardness from the obtained indent curve based on ISO14577. The constant ε related to the indenter shape was set to ε = 0.75. The results are shown in Table 1.

(Evaluation of tensile modulus)
A monolayer of an organic film and an inorganic layer was prepared by the above method, respectively. The obtained monolayer was subjected to a dynamic viscoelasticity measuring device (DVA-200, manufactured by IT Measurement and Control Co., Ltd.) under the conditions of a constant speed temperature rise tensile mode, a temperature rise rate of 10 ° C./min, and a frequency of 10 Hz. The rate was measured.

<Evaluation>
The laminates obtained in Examples and Comparative Examples were evaluated as follows. The results are shown in Table 1.

(Evaluation of connection reliability)
The conduction of current was confirmed for the electrodes located at the center of the wafer and the positions of 5 cm and 10 cm from the center of the wafer of the laminates obtained in Examples and Comparative Examples, and the initial connection reliability was evaluated according to the following criteria. The electrodes at each position are daisy chains consisting of 10 × 10 electrodes.
◯: When there is continuity after wafer bonding at all positions ×: When there is a conduction failure part after wafer bonding

Next, the laminated body was left at -40 ° C for 30 minutes, then heated to 125 ° C and left for 30 minutes, and 100 sets or 300 sets were carried out (reliability test) as one set, and then the above initial connection was performed. The same evaluation as the reliability was performed, and the connection reliability after the reliability test was evaluated.
⊚: When all positions are conducting after 300 sets ○: When all positions are conducting after 100 sets and there is a conduction failure part after 300 sets ×: When there is a continuity failure part after 100 sets

(Evaluation of adhesive reliability)
The peeling area of the electrode portion arranged at the center of the wafer and 5 cm and 10 cm from the center of the wafer was measured with an ultrasonic imaging device. Based on the obtained peeled area, the adhesive reliability was evaluated according to the following criteria. The evaluation was performed on the laminated body before the reliability test (initial stage) and after the reliability test (100 sets), respectively.
⊚: Peeling area is less than 5% ○: Peeling area is 5% or more and less than 30% ×: Peeling area is 30% or more

According to the present invention, there are provided a laminate having high electrical connection reliability, a curable resin composition used for the laminate, a method for producing the laminate, and a semiconductor device and an image pickup apparatus having the laminate. Can be done.

1 1st substrate 2 2nd substrate 3 Electrode 4 Organic film 5 Through hole 6 Inorganic layer 7 Barrier metal layer

Claims (19)

A first substrate having an electrode, an organic film, and a second substrate having an electrode are provided in this order, and the electrode possessed by the first substrate and the electrode possessed by the second substrate are the organic film. A laminate that is electrically connected through a through hole that penetrates the. The laminate according to claim 1, wherein the organic film has a weight loss rate of 5% or less after heat treatment at 400 ° C. for 4 hours. The laminate according to claim 1 or 2, wherein the organic film satisfies that the surface hardness measured by a nanoindenter is 5 GPa or less. The laminate according to any one of claims 1 to 3, wherein the organic film is a cured product of a curable resin composition. The laminate according to any one of claims 1 to 4, wherein the organic film contains a compound having a structure represented by the following general formula (1).

Here, P ¹ represents an alicyclic group or an aromatic group. Q ¹ represents a linear, branched or cyclic aliphatic group or an aromatic group. The aliphatic group and the aromatic group may or may not have a substituent. S1 represents a natural number of 1 or more. The laminate according to claim 5, wherein at least one ^{of P 1 and} Q ¹ of the general formula (1) has a fluorine element. The laminate according to any one of claims 1 to 6, wherein the organic film contains a silane coupling agent. The laminate according to any one of claims 1 to 7, which has an inorganic layer having a thickness of 1 nm or more and 1 μm or less between the first substrate and the second substrate. The laminate according to any one of claims 1 to 8, which has a barrier metal layer on the surface of the through hole. A first substrate having an electrode, an organic film, and a second substrate having an electrode are provided in this order, and the electrode possessed by the first substrate and the electrode possessed by the second substrate are the organic film. A curable resin composition used for the organic film of a laminate electrically connected through a through hole penetrating the structure. The curable resin composition according to claim 10, wherein the curable resin composition has a tensile elastic modulus of 5 GPa or less at 25 ° C. of the cured product. The curable resin composition according to claim 10 or 11, which contains a compound having a structure represented by the following general formula (1).

Here, P ¹ represents an alicyclic group or an aromatic group. Q ¹ represents a linear, branched or cyclic aliphatic group or an aromatic group. The aliphatic group and the aromatic group may or may not have a substituent. S1 represents a natural number of 1 or more. The curable resin composition according to claim 12, which has a fluorine element in at least one ^{of P 1 and} Q ¹ of the general formula (1). The curable resin composition according to claim 12 or 13, further having a benzoxazine structure. The curable resin composition according to any one of claims 10 to 14, which contains a silane coupling agent. Claims 12 to 12 to claim, wherein the content of the compound having the structure represented by the general formula (1) is 80 parts by weight or more and 99.5 parts by weight or less in 100 parts by weight of the solid content in the curable resin composition. The curable resin composition according to any one of 15. The process of forming an organic film on the surface on which the electrodes of the first substrate having the electrodes are formed, and
The step of forming a through hole in the organic film and
A step of filling the through hole with a conductive material, and a step of polishing the surface of the substrate on the side filled with the conductive material to form a bonded electrode.
A method for manufacturing a laminated body, comprising a step of bonding the first substrate on which the bonded electrodes are formed and the second substrate on which the bonded electrodes are formed so that the bonded electrodes are bonded to each other. A semiconductor device having the laminate according to any one of claims 1 to 9. An image pickup apparatus having the laminate according to any one of claims 1 to 9.

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