JP2006228908A - Method for forming insulating film, multilayer wiring board, electronic device, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming an insulating film by which the insulating film can be formed without performing flattening treatment such as chemical mechanical polishing method or the like, a multilayer wiring substrate which is provided with an insulating film formed by the method therefor, a highly reliable electronic device and an electronic apparatus. <P>SOLUTION: The method for forming an insulating film 4 is used to insulate conductors 3 formed on a substrate 2, and it includes a first step to fill a first insulating material 41 by a liquid-phase film formation method to bury a space between the conductors 3, and a second step to supply a second insulating material 42 by a vapor-phase film formation method to cover the conductors 3 and the first filling material 41 and to obtain the insulating film 4 as a result. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for forming an insulating film, a multilayer wiring board, an electronic device, and an electronic apparatus.

2. Description of the Related Art In recent years, multilayer wiring boards have come to be used as electronic devices become more sophisticated and smaller. This multilayer wiring board is generally manufactured as follows.
First, after forming a lower wiring layer on a substrate, an interlayer insulating film is formed using, for example, a vapor deposition method so as to cover the lower wiring layer.
Next, the surface of the interlayer insulating film is planarized using a chemical mechanical polishing (CMP) method (see, for example, Patent Document 1).
Next, a part of the interlayer insulating film is removed by etching, and a contact hole is formed so that a part of the lower wiring layer is exposed.

Next, a conductive material is supplied so as to fill the contact hole to form a connection portion.
Next, an upper wiring layer is formed on the interlayer insulating film so as to be in contact with the connection portion. Thereby, the lower wiring layer and the upper wiring layer are electrically connected.
A multilayer wiring board can be obtained by repeating the above steps a plurality of times.
However, in such a method, it is necessary to flatten the surface every time an interlayer insulating film is formed. However, the operation (work) takes time and labor, resulting in an increase in manufacturing cost. There is a problem of inviting.

JP 2004-158885 A

  An object of the present invention is, for example, a method for forming an insulating film that can form an insulating film that does not require a planarization process such as a chemical mechanical polishing method, a multilayer wiring board including an insulating film formed by the method for forming such an insulating film, An object is to provide a highly reliable electronic device and electronic apparatus.

Such an object is achieved by the present invention described below.
The method for forming an insulating film of the present invention is a method for forming an insulating film for insulating conductors provided on a base material,
A first step of filling a first insulating material by a liquid phase film forming method so as to fill a space between the conductors;
And a second step of obtaining the insulating film by supplying a second insulating material by a vapor deposition method so as to cover the conductors and the first insulating material.
Thus, a planarized insulating film can be obtained without requiring a planarization process such as a chemical mechanical polishing method.

In the insulating film forming method of the present invention, it is preferable that in the first step, the first insulating material is filled so as to be substantially equal to the thickness of the conductor.
Thereby, since the surface on the opposite side to the base material of each conductor and the first insulating material can be made flatter, the surface on the opposite side to the base material of the insulating film to be formed is also flatter It becomes.

In the method for forming an insulating film of the present invention, it is preferable to use an inkjet method as the liquid phase film forming method in the first step.
According to this method, since the liquid material can be selectively supplied to the space between the conductors, it is possible to reliably prevent the first insulating material from adhering to the surface of the conductor opposite to the base material. Can do.

In the insulating film forming method of the present invention, it is preferable to use a thermal CVD method or a plasma CVD method as the vapor phase film forming method in the second step.
By using such a method, the second insulating material can be supplied to the surface opposite to the conductor and the base material of the first insulating material in a higher density and a uniform amount.
In the insulating film forming method of the present invention, in the second step, the vapor phase film forming method is preferably performed at an atmospheric temperature lower than a temperature at which the conductor melts.
Thereby, when supplying a 2nd insulating material, it can prevent reliably that each conductor melts unintentionally.

In the insulating film forming method of the present invention, it is preferable that the first insulating material and the second insulating material are of the same type.
Thereby, the adhesiveness of a 1st insulating material and a 2nd insulating material can be improved more. As a result, peeling or the like at the interface between the first insulating material and the second insulating material can be prevented, and the film strength of the entire insulating film can be improved.

In the insulating film forming method of the present invention, it is preferable that the first insulating material is mainly composed of silicon dioxide.
Silicon dioxide is a highly insulating material and can be filled in a space between conductors with a relatively high density by a liquid phase film forming method. For this reason, conductors can be more reliably insulated by using the thing which has silicon dioxide as a main component as a 1st insulating material.

In the insulating film forming method of the present invention, the second insulating material is preferably composed mainly of silicon dioxide.
Silicon dioxide formed by a vapor deposition method exhibits particularly excellent insulating properties. For this reason, the insulating property as the whole insulating film obtained further improves by using what has silicon dioxide as a main component as a 2nd insulating material.
Further, when a conductor is further provided on the insulating film, it is possible to more reliably insulate the conductor and the lower layer conductor.

In the method for forming an insulating film of the present invention, prior to the first step, liquid repellency is imparted to the liquid material used in the liquid phase film forming method on the surface of the conductor opposite to the base. It is preferable to have a step of performing a liquid repellent treatment.
Thereby, when supplying a liquid material to the space between conductors, it is suitable for a liquid material (1st insulating material) to adhere unintentionally to the surface on the opposite side to the base material of each conductor. Can be prevented.

Preferably, the method for forming an insulating film of the present invention includes a step of removing the portion subjected to the liquid repellent treatment prior to the second step.
As a result, the surface of the conductor and the first insulating material opposite to the base can be further flattened, and variation in wettability with respect to the second insulating material and its precursor at each part of the surface can be reduced. can do. As a result, variations in the supply amount of the second insulating material in each part of the surface opposite to the conductor and the base material of the first insulating material are prevented. Thereby, the upper surface of the obtained insulating film can be further flattened.

In the method for forming an insulating film of the present invention, prior to the first step, a third insulating material is applied to the surface of the conductor and the surface of the base material exposed from the conductor by a vapor deposition method. It is preferable to have a film forming step of continuously forming a film as a main material.
Thereby, since the highly insulating film formed by the vapor deposition method can be interposed between the conductors, the conductors can be more reliably insulated from each other. This also allows the first insulating material supplied by the liquid phase film forming method to be covered with the second insulating material and the third insulating material supplied at high density by the vapor phase film forming method. Therefore, even when the insulating film is exposed to a high temperature environment, an effect of preventing gas generation from the insulating film can be obtained.

In the method for forming an insulating film of the present invention, in the coating film forming step, when the average thickness of the coating film is C [nm] and the average thickness of the conductor is D [nm], C / D is 0. The film is preferably formed so as to satisfy the relationship of 0.02 to 0.2.
As a result, a reliable insulating effect by the coating film is exhibited while preventing the thickness of the insulating film from becoming unnecessarily large.

In the insulating film forming method of the present invention, it is preferable that the third insulating material is the same type as the second insulating material.
Thereby, the adhesiveness between the second insulating material and the third insulating material (film) becomes high. This also substantially increases the contact area of the second insulating material with the conductor, thereby further improving the effect of preventing the insulating film from peeling off from each conductor.

In the insulating film forming method of the present invention, it is preferable that the third insulating material is mainly composed of silicon dioxide.
Thereby, the adhesiveness between the second insulating material and the third insulating material (coating film) becomes higher, and the effect of preventing the insulating film from peeling off from each conductor is further improved.
In the method for forming an insulating film of the present invention, the insulating film preferably has a flatness (specified in JIS B 0621) of the surface opposite to the substrate of 300 nm or less.
Since the insulating film having the flatness in such a range has sufficiently high flatness, even when a conductor is further formed on the insulating film, planarization of the surface can be omitted.

The multilayer wiring board of the present invention includes an insulating film formed by the method for forming an insulating film of the present invention.
Thereby, a highly reliable multilayer wiring board provided with the planarized insulating film is obtained.
An electronic device according to the present invention includes the multilayer wiring board according to the present invention.
Thereby, an electronic device with high reliability can be obtained.
An electronic apparatus according to the present invention includes the electronic device according to the present invention.
As a result, a highly reliable electronic device can be obtained.

Hereinafter, the method for forming an insulating film, the multilayer wiring board, the electronic device, and the electronic apparatus of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
<Method for forming insulating film>
First, a preferred embodiment of the method for forming an insulating film of the present invention will be described.
<< First Embodiment >>
First, a first embodiment of the method for forming an insulating film of the present invention will be described.
FIG. 1 is a diagram (longitudinal sectional view) for explaining a first embodiment of a method for forming an insulating film according to the present invention. In the following description, the upper side in the figure is referred to as “upper” and the lower side is referred to as “lower”.

  The insulating film forming method shown in FIG. 1 includes: [1-1] a liquid repellent treatment process for applying a liquid repellent treatment to the upper surface of each conductor 3; [1-2] a space 30 between the conductors 3; A first insulating material filling step of filling the first insulating material 41 by a liquid phase film forming method, [1-3] a liquid repellent treatment portion removing step of removing a portion subjected to the liquid repellent treatment, and [1 -4] a second insulating material supply step for supplying the second insulating material 42 by a vapor deposition method so as to cover each conductor 3 and the first insulating material 41.

Hereinafter, each process will be described sequentially.
[1-1] Liquid Repellent Treatment Step First, as shown in FIG. 1A, a substrate (base material) 2 on which a plurality of conductors (wirings) 3 are formed is prepared.
Each of the conductors 3 is made of, for example, Au, Ag, Pt, Cu, Ni, Al, or an alloy containing these.

Next, a liquid repellent treatment for imparting liquid repellency to the liquid material used in the next step [1-2] is performed on the upper surface (surface opposite to the substrate 2) of each conductor 3.
Thus, in the next step [1-2], when the liquid material is supplied to the space 30 between the conductors 3, the liquid material (first insulating material 41) is not formed on the upper surface of each conductor 3. Adherence can be suitably prevented.

This liquid repellent treatment is, for example, one or two of a method of forming a liquid repellent film on the upper surface of each conductor 3 and a method of implanting (implanting) ions that can impart liquid repellency such as fluorine ions. A combination of the above can be used.
Among these, for the liquid repellent treatment, it is preferable to use a method of forming the liquid repellent film 5 on the upper surface of each conductor 3 as shown in FIG. According to this method, liquid repellency can be imparted to the upper surface of each conductor 3 relatively easily.

The liquid repellent film 5 can be formed, for example, by supplying a liquid repellent film forming material and then drying it if necessary.
In this case, the liquid repellent film 5 may be formed so as to cover the entire top surface of the substrate 2 and then remove unnecessary portions, but is selectively formed on the top surface of each conductor 3. It is preferable to do this.

  As a method for selectively supplying the liquid repellent film forming material to the upper surface of each conductor 3, for example, a pad or stamper impregnated with the liquid repellent film forming material is brought into contact with the upper surface of each conductor 3. Examples thereof include a method and a method of discharging a liquid repellent film forming material onto the upper surface of each conductor 3 by an ink jet method, and the former method is preferably used. According to such a method, the liquid repellent film 5 can be selectively formed on the upper surface of each conductor 3 relatively easily and reliably.

Examples of the constituent material of the liquid repellent film 5 include a coupling agent having a functional group exhibiting liquid repellency, a liquid repellent resin material, and the like.
Further, as the liquid repellent film forming material, a solution or dispersion prepared by mixing these with a solvent or dispersion medium can be used.
As the coupling agent, for example, a silane coupling agent, a titanium coupling agent, an aluminum coupling agent, a zirconium coupling agent, an organic phosphate coupling agent, a silyl peroxide coupling agent, or the like is used. be able to.

Examples of the functional group exhibiting liquid repellency include a fluoroalkyl group, an alkyl group, a vinyl group, an epoxy group, a styryl group, and a methacryloxy group.
Specific examples of the coupling agent include, for example, tridecafluoro-1,1,2,2 tetrahydrooctyltriethoxysilane, tridecafluoro-1,1,2,2 tetrahydrooctyltrimethoxysilane, and tridecafluoro-1 , 1,2,2 tetrahydrooctyltrichlorosilane, octadecyltrimethoxysilane, vinyltrimethoxysilane and the like.

  On the other hand, examples of liquid repellent resin materials include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), ethylene-tetrafluoroethylene copolymer (ETFE), and perfluoro. Examples thereof include fluorine-based resins such as ethylene-propene copolymer (FEP) and ethylene-chlorotrifluoroethylene copolymer (ECTFE).

  Examples of the solvent or dispersion medium include inorganic solvents such as nitric acid, sulfuric acid, ammonia, hydrogen peroxide, water, carbon disulfide, carbon tetrachloride, and ethylene carbonate, methyl ethyl ketone (MEK), acetone, diethyl ketone, and methyl. Ketone solvents such as isobutyl ketone (MIBK), methyl isopropyl ketone (MIPK), cyclohexanone, alcohol solvents such as methanol, ethanol, isopropanol, ethylene glycol, diethylene glycol (DEG), glycerin, diethyl ether, diisopropyl ether, 1, 2 -Dimethoxyethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), anisole, diethylene glycol dimethyl ether (diglyme), diethylene glyco Ether solvents such as ruethyl ether (carbitol), cellosolv solvents such as methyl cellosolve, ethyl cellosolve, phenyl cellosolve, aliphatic hydrocarbon solvents such as hexane, pentane, heptane, cyclohexane, toluene, xylene, benzene, trimethyl Aromatic hydrocarbon solvents such as benzene and tetramethylbenzene, aromatic heterocyclic compounds solvents such as pyridine, pyrazine, furan, pyrrole, thiophene and methylpyrrolidone, N, N-dimethylformamide (DMF), N, N- Amide solvents such as dimethylacetamide (DMA), halogen compound solvents such as dichloromethane, chloroform, 1,2-dichloroethane, ester solvents such as ethyl acetate, methyl acetate, ethyl formate, dimethyl sulfoxide (DMSO), sulfolane, etc. Various organic solvents such as sulfur compound solvents, nitrile solvents such as acetonitrile, propionitrile, acrylonitrile, organic acid solvents such as formic acid, acetic acid, trichloroacetic acid, trifluoroacetic acid, or mixed solvents containing these. Can be mentioned.

The concentration of the constituent material of the liquid repellent film 5 in the material for forming the liquid repellent film is preferably set as follows, for example, depending on the type of the constituent material.
In the case of a coupling agent, the amount is preferably about 0.01 to 0.5 wt%, more preferably about 0.1 to 0.3 wt%. Moreover, in the case of a resin material, it is preferable that it is about 0.01-0.5 wt%, and it is more preferable that it is about 0.1-0.3 wt%.
In addition, this process [1-1] can also be abbreviate | omitted by the supply method of the liquid material etc. which are used for the liquid phase film-forming method of the following process [1-2].

[1-2] First insulating material filling step (first step)
Next, as shown in FIG. 1C, the first insulating material 41 is filled in the space 30 between the conductors 3 by a liquid phase film forming method. As a result, a filling portion whose main material is the first insulating material 41 is formed in the space 30.
According to the liquid phase film forming method, the first insulating material 41 can be selectively filled into the space 30 relatively easily without requiring large equipment such as a vacuum apparatus or a mask pattern.

Here, as the first insulating material 41, for example, silicon dioxide such as silicon dioxide (SiO ₂ ), hydrogen-containing silsesquioxane (HSQ), or methyl group-containing silsesquioxane (MSQ), silicon nitride (SiN), inorganic insulating materials such as nitrides such as titanium nitride (TiN), polyimide resins, polyparaxylylene, benzocyclobutene, polyvinylphenol, aromatic resins such as novolac resins, polytetrafluoroethylene Organic insulating materials such as fluorine resins such as (PTFE), acrylic resins such as polymethyl methacrylate (PMMA), polyolefin resins such as polyethylene, polypropylene, polyisobutylene and polybutene, and polyamide resins. , Combining one or more of these It is possible to have.

  Among these, as the first insulating material 41, a silicon oxide, particularly, a material mainly composed of silicon dioxide is preferable. Silicon oxide is a highly insulating material. Silicon dioxide is a material that can be filled in the space 30 between the conductors 3 at a relatively high density by a liquid phase film forming method. For this reason, the conductors 3 can be more reliably insulated from each other by using a material mainly composed of silicon dioxide as the first insulating material 41.

Specifically, this step [1-2] is performed as follows.
First, a liquid material containing the first insulating material 41 and / or its precursor as described above is prepared.
As the solvent or dispersion medium used for the preparation of the liquid material, the same solvents as described in the above step [1-1] can be used.

Next, the prepared liquid material is supplied to the space 30 by a liquid phase film forming method.
Examples of the liquid phase film forming method include an inkjet method, a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, a bar coating method, a roll coating method, a wire bar coating method, a dip coating method, and a spray coating method. , A screen printing method, a flexographic printing method, an offset printing method, a microcontact printing method, and the like can be used in combination, or among these, the inkjet method is particularly preferable.
According to the ink jet method, since the liquid material can be selectively supplied to the space 30, the first insulating material 41 can be reliably prevented from adhering to the upper surface of the conductor 3.

Thereafter, a predetermined treatment is performed on the liquid material. As a result, the space 30 can be filled with the first insulating material 41.
For example, when a liquid material containing a precursor of the first insulating material 41 (hereinafter simply referred to as “precursor”) is used, a process of changing the precursor to the first insulating material 41 is performed.
This treatment is appropriately selected according to the type of the precursor and is not particularly limited, and examples thereof include heating and ultraviolet irradiation.
Prior to this treatment, at least a part of the solvent or dispersion medium used for preparing the liquid material may be removed.

Specifically, when the first insulating material 41 is mainly composed of silicon dioxide, examples of the precursor thereof include dichlorosilane, hexachlorodisilane, tetraethoxysilane, tetrakis (hydrocarbylamino) silane, and tris (hydrocarbyl). Amino) silane and the like, and can be changed to silicon dioxide by heating in an oxidizing atmosphere.
Further, for example, when a liquid material containing the first insulating material 41 itself is used, a treatment for removing the solvent or the dispersion medium in the liquid material is performed.
Examples of the method for removing the solvent or the dispersion medium include a heating method, vacuum (reduced pressure) drying, and a method of blowing an inert gas.

Here, in the post-process [1-4], since the second insulating material 42 is supplied by a vapor deposition method, the upper surface of each conductor 3 and the upper surface of the filling portion (first insulating material 41). (Hereinafter referred to as “second insulating material supply surface”) is deposited at a substantially constant rate (thickness), but prior to supplying the second insulating material 42, the first insulating material 41 is deposited. Is filled in the space 30, the second insulating material supply surface is flattened, and the upper surface of the layer composed mainly of the second insulating material 42, that is, the upper surface of the insulating film 4 to be formed. Can be made flat.
Thereby, the planarization process (for example, chemical polishing method etc.) of the insulating film surface which was conventionally required when manufacturing a multilayer wiring board can be omitted.

  From this viewpoint, it is preferable that the first insulating material 41 is filled so as to be approximately equal to the thickness of each conductor 3. Thereby, the 2nd insulating material supply surface can be made more flat, and the said effect can be improved more. In addition, for this reason, for example, the relative dielectric constant of the entire insulating film 4 obtained as a result of a part of the layer composed mainly of the second insulating material 42 entering the upper portion of the space 30 is the target. Deviation from the value can also be suitably prevented.

[1-3] Liquid Repellent Treatment Part Removal Step Next, the portion (region) to which liquid repellency is imparted in the step [1-2] is removed.
Thereby, the second insulating material supply surface can be further flattened, and variation in wettability with respect to the second insulating material 42 and its precursor in each part of the surface can be reduced. That is, the physical and chemical characteristics of the second insulating material supply surface can be made uniform. As a result, variation in the supply amount of the second insulating material 42 at each portion of the second insulating material supply surface is prevented.

Thus, prior to the next step [1-4], by removing the portion (region) imparted with liquid repellency, the upper surface of the obtained insulating film 4 can be further planarized.
Examples of the method for removing the portion imparted with liquid repellency include physical etching methods such as plasma etching, reactive ion etching, beam etching, and light-assisted etching, and chemical etching methods such as wet etching. One kind or a combination of two or more kinds can be used.
In addition, this process [1-3] can also be abbreviate | omitted depending on the kind etc. of the vapor-phase film-forming method used for the following process [1-4].

[1-4] Second insulating material supply step (second step)
Next, as shown in FIG. 1D, the second insulating material 42 is formed by a vapor deposition method so as to cover each conductor 3 and the first insulating material 41 (second insulating material supply surface). Is supplied in layers (or films). Thereby, a layer (covering layer) composed mainly of the second insulating material 42 is formed.

According to the vapor deposition method, the second insulating material 42 can be supplied at a high density, so that the layer composed of the second insulating material as a main material becomes dense, and the resulting insulating film 4 is obtained. The overall insulation is further improved.
In the case where a conductor is further provided on the insulating film 4, the conductor and the underlying conductor 3 can be reliably insulated.

Furthermore, since the layer formed by the vapor deposition method is also excellent in adhesion with the conductor 3, even if the adhesion between the first insulating material 41 and the conductor 3 is slightly low, Since the adhesion to each conductor 3 is ensured, it is possible to prevent the insulating film 4 from being peeled off from each conductor 3 as a whole.
Here, examples of the second insulating material 42 include silicon dioxide, silicon oxide such as fluorine-containing silsesquioxane, and carbon-containing silsesquioxane, and nitrides such as silicon nitride and titanium nitride. Organic insulating materials such as inorganic insulating materials, polyparaxylylene, polyvinylphenol, aromatic resins such as novolac resins, fluorine resins such as polytetrafluoroethylene (PTFE), carbon materials such as amorphous carbon, etc. 1 type or 2 types or more of these can be used in combination.

  Among these, as the second insulating material 42, a silicon oxide, particularly, a material mainly composed of silicon dioxide is preferable. As described above, silicon oxide is a highly insulating material. In addition, silicon dioxide formed by a vapor deposition method exhibits particularly excellent insulating properties. For this reason, the said effect can be improved more by using the thing which has silicon dioxide as a main component as the 2nd insulating material 42. FIG.

The first insulating material 41 and the second insulating material 42 may be different types (compositions) of materials, but it is preferable to use the same type. Thereby, the adhesiveness of the 1st insulating material 41 and the 2nd insulating material 42 can be improved more. As a result, peeling or the like at the interface between the first insulating material 41 (filling portion) and the second insulating material 42 (covering layer) can be prevented, and the film strength of the entire insulating film 4 can be improved. it can.
From these facts, as the combination of the first insulating material 41 and the second insulating material 42, it is optimal that all of them are composed mainly of silicon dioxide.

  Examples of the vapor deposition method used in this step [1-4] include a chemical vapor deposition method (CVD method) such as a thermal CVD method, a plasma CVD method, and a laser CVD method, a vacuum vapor deposition method, and sputtering (low temperature). Sputtering) method, physical vapor deposition method such as ion plating method (PVD method), thermal oxidation method, etc. can be used alone or in combination of two or more, chemical vapor deposition method, In particular, it is preferable to use a thermal CVD method or a plasma CVD method.

By using this method, the second insulating material 42 can be supplied to the second insulating material supply surface in a higher density and a uniform amount.
Here, when a chemical vapor deposition method is used as the vapor deposition method, a precursor of the second insulating material may be used as a material for supplying the second insulating material 42.
When a physical vapor deposition method is used as the vapor deposition method, the second insulating material itself may be used as a material for supplying the second insulating material 42.

For example, when the second insulating material 42 mainly composed of silicon dioxide is supplied by a thermal CVD method, a gas (carrier gas) containing a silicon oxide precursor and oxygen atoms in a chamber having a predetermined pressure. Can be performed by heating the inside of the chamber.
Examples of the silicon oxide precursor include dichlorosilane, hexachlorodisilane, tetraethoxysilane, tetrakis (hydrocarbylamino) silane, and tris (hydrocarbylamino) silane, and one or more of these are combined. Can be used.

Examples of the gas containing oxygen atoms include oxygen (pure oxygen), ozone, hydrogen peroxide, water vapor, nitrogen monoxide, nitrogen dioxide, dinitrogen oxide, and the like. They can be used in combination.
The temperature in the chamber (atmosphere temperature) is not particularly limited, but is preferably set below the temperature at which the conductor 3 melts. For example, when each conductor 3 is made of Al, the temperature of the atmosphere is preferably set to less than 450 ° C. Thereby, when supplying the 2nd insulating material 42, it can prevent reliably that each conductor 3 melts unintentionally.

The heating time (heating time) varies slightly depending on the temperature in the chamber, but is preferably about 10 to 90 minutes, more preferably about 20 to 60 minutes.
The pressure (degree of vacuum) in the chamber is preferably about 0.05 Torr to atmospheric pressure (760 Torr), and more preferably about 0.1 to 500 Torr.
The mixing ratio between the silicon oxide precursor and the gas containing oxygen atoms is preferably about 10: 1 to 1: 100, more preferably about 1: 2 to 1:10 in terms of molar ratio. .

Further, for example, when the second insulating material 42 mainly composed of silicon dioxide is supplied by the plasma CVD method, oxygen atoms are replaced by high frequency power instead of heating the chamber in the thermal CVD method. This can be done by plasma-exciting the containing gas.
The output of the high-frequency power is preferably about 100 to 500 W, and more preferably about 250 to 350 W.

According to the plasma CVD method, the supplied insulating material 42 can reach the upper surface of the conductor 3 in a high energy state. In addition, the deposit adhered to the upper surface of the conductor 3 can be removed by the plasma-excited gas, and the upper surface itself can be roughened. Such a factor causes higher adhesion between the upper surface of the conductor 3 and the second insulating material 42. That is, higher adhesion can be obtained between the conductor 3 and the layer composed mainly of the second insulating material.
Through the steps as described above, the insulating film 4 composed of the first insulating material 41 (filling portion) and the second insulating material 42 (covering layer) can be obtained.

  The upper surface of such an insulating film 4 has a flatness (specified in JIS B 0621) of preferably 300 nm or less, and more preferably 100 nm or less. Since the insulating film 4 having the flatness in such a range has sufficiently high flatness, even when a conductor is further formed on the insulating film 4, the surface is flattened by using, for example, a chemical polishing method. It can be omitted.

<< Second Embodiment >>
Next, a second embodiment of the method for forming an insulating film according to the present invention will be described.
FIG. 2 is a longitudinal sectional view showing a configuration of an insulating film formed according to the second embodiment of the insulating film forming method of the present invention. In the following description, the upper side in FIG. 2 is referred to as “upper” and the lower side is referred to as “lower”.

Hereinafter, the second embodiment will be described with a focus on differences from the first embodiment, and description of similar matters will be omitted.
In the second embodiment, prior to the step [1-1] (liquid repellent treatment step), the surface of each conductor 3 and the surface of the substrate 2 exposed from each conductor 3 are subjected to a first vapor deposition method. 3 is the same as that of the first embodiment except that a film forming step of continuously forming a film mainly composed of the insulating material 43 is used.

Thereby, since the highly insulating film formed by the vapor deposition method can be interposed between the conductors 3, the conductors 3 can be more reliably insulated from each other. . In addition, as a result, the first insulating material 41 (filling portion) supplied by the liquid phase film forming method and the second insulating material 42 (covering layer) supplied by the vapor phase film forming method at a high density Therefore, even when the insulating film 4 is exposed to a high temperature environment, the effect of preventing gas generation from the insulating film 4 can be obtained.
For this vapor deposition method, the same method as described in the above-mentioned step [1-4] can be used.

As the third insulating material 43, the same material as that described for the second insulating material 42 can be used, but the same material as the second insulating material 42 is preferably used. Thereby, the adhesiveness of the 2nd insulating material 42 (coating layer) and the 3rd insulating material 43 (film) becomes a high thing. Moreover, since the contact area with the conductor 3 of the 2nd insulating material 42 increases substantially by this, the peeling prevention effect from each conductor 3 of the insulating film 4 improves more.
For this reason, the third insulating material 43 is preferably composed mainly of silicon oxide, particularly silicon dioxide, like the first insulating material 41 and the second insulating material 42. Thereby, the effect can be further improved.

Further, in such a coating, when the average thickness of the coating is C [nm] and the average thickness of each conductor 3 is D [nm], C / D is 0.02 to 0.2. Is preferably formed so as to satisfy the above relationship, and more preferably formed so as to satisfy the relationship of 0.05 to 0.1. Thereby, while preventing the thickness of the insulating film 4 from becoming unnecessarily large, a reliable insulating effect by the coating film is exhibited.
Since the insulating film 4 formed as described above has a sufficiently flat surface (upper surface), a planarization process such as a chemical polishing method can be omitted. Therefore, by using the method for forming an insulating film of the present invention, time and labor can be reduced, and further, the manufacturing cost of the insulating film can be reduced.

<Electronic device>
Next, a semiconductor device (electronic device of the present invention) including a multilayer wiring board formed by applying the insulating film forming method of the present invention will be described.
FIG. 3 is a longitudinal sectional view showing an embodiment in which the electronic device of the present invention is applied to a semiconductor device. In the following description, the upper side in FIG. 3 is referred to as “upper” and the lower side is referred to as “lower”.

The semiconductor device 100 includes a multilayer wiring board 20, a semiconductor element 10 mounted on the multilayer wiring board 20 via ball bumps 52, a cover 60 that protects the semiconductor element 10, and other semiconductor devices controlled by the semiconductor device 100. It has a ball bump 51 connected to the electronic device.
The multilayer wiring board 20 includes a base substrate 21 that serves as a support for the multilayer wiring board 20 and a multilayer wiring portion 22 provided on the base substrate 21.

  The multilayer wiring portion 22 includes a plurality of conductors (wirings) 31 provided on the base substrate 21 and an interlayer insulating film 40 formed so as to cover the base substrate 21 provided with the conductors 31. And a connecting portion 32 for electrically connecting the lower layer conductor 31 and the upper layer conductor 31 at a predetermined position. The conductor 31, the interlayer insulating film 40, and the connection portion 32 are further laminated twice.

The conductor 31 and the connection part 32 are each made of, for example, Au, Ag, Pt, Cu, Ni, Al, or an alloy containing these.
Each average thickness of each conductor 31 is slightly different depending on the type of constituent material, but is preferably about 100 to 1000 nm, and more preferably about 500 to 800 nm. When the average thickness of each conductor 31 is less than the lower limit, problems such as a decrease in electric capacity and an increase in resistance of the conductor 31 may occur, thereby reducing the reliability of the multilayer wiring board 20. There is. Moreover, when the average thickness exceeds the upper limit, the thickness of the entire multilayer wiring board 20 becomes undesirably large.

In the interlayer insulating film 40, the average thickness from the upper surface of the conductor 31 to the interlayer insulating film 40 is preferably about 50 to 800 nm, and more preferably about 100 to 500 nm. As a result, the upper and lower conductors 31 are reliably insulated from each other, and the thickness of the entire multilayer wiring board 20 can be reliably prevented from becoming unnecessarily thick.
As a constituent material of the base substrate 21, for example, silicon such as polycrystalline silicon and amorphous silicon, various semiconductor materials such as germanium and gallium arsenide, various glass materials, various resin materials, and the like can be used.

In addition, a conductive portion 33 penetrating in the thickness direction of the base substrate 21 is connected to the base substrate 21 so that the conductor 31 provided on the base substrate 21, that is, the lowermost layer, and the ball bump 51 are electrically connected. Is provided. Ball bumps 51 are provided on the lower surface of the base substrate 21 so as to be electrically connected to the conductive portion 33.
As the constituent material of the conductive portion 33, the same materials as described in the conductor 31 and the connecting portion 32 can be used.

The constituent material of the ball bump 51 is substantially free of Pb such as Pb-containing solder such as Pb—Sn solder, Sn—Ag solder, Sn—Ag—Cu solder, etc. Pb-free solder (Pb-free solder), silver solder, copper solder, phosphor copper solder, brass solder, aluminum solder, nickel solder and the like can be used.
Mounted on the upper part of the multilayer wiring portion 22 is the semiconductor element 10 electrically connected to the conductor 31 provided in the uppermost layer via the ball bump 52 and the connection portion 32.

As the constituent material of the ball bump 52, the same material as described for the ball bump 51 can be used.
On the semiconductor element 10, there is provided a cover 60 composed of a buffer material 61 that reduces the impact from the cover member 62 to the semiconductor element 10 and a cover member 62 that substantially protects the semiconductor element 10. Yes.

Examples of the constituent material of the cover member 62 include various resin materials, glass materials, and the like, and one or more of these can be used in combination.
The buffer material 61 is provided between the semiconductor element 10 and the cover member 62 and also functions as a heat dissipation material that radiates heat generated from the semiconductor element 10.
Such a semiconductor device 100 can be manufactured as follows, for example.

[2-1] First, a plurality of ball bumps 51 are formed on the lower surface of the base substrate 21 provided with the conductive portion 33 so as to be electrically connected to the conductive portion 33.
[2-2] Next, a plurality of conductors 31 are formed on the upper surface of the base substrate 21 so as to be electrically connected to the conductive portion 33 included in the base substrate 21.
The conductor 31 can be formed, for example, by forming a metal film so as to cover the base substrate 21 and then removing unnecessary portions of the metal film.

For the formation of the metal film, for example, chemical vapor deposition (CVD) such as thermal oxidation, thermal CVD, plasma CVD, laser CVD, vacuum deposition, sputtering (low temperature sputtering), dry plating methods such as ion plating, In addition to wet plating methods such as electrolytic plating and electroless plating, metal foil bonding or the like can be used.
Moreover, as a removal method of a metal film, it can use, for example, combining 1 type (s) or 2 or more types among the physical etching methods, chemical etching methods, etc. which were mentioned above.

[2-3] Next, an interlayer insulating film 40 is formed on the base substrate 21 so as to cover the conductor 31. The insulating film forming method of the present invention is applied to the formation of the interlayer insulating film 40.
[2-4] Next, contact holes are formed at predetermined positions of the interlayer insulating film 40. This contact hole is formed at a position where the lower conductor 31 and the upper conductor 31 should be electrically connected.
The contact hole is obtained, for example, by forming a resist layer having an opening in a region where the contact hole is to be formed by a photolithography method or the like and then etching the interlayer insulating film 40 using the resist layer as a mask. Can do.

The resist layer is obtained by applying (supplying) a resist material on the interlayer insulating film 40, and then exposing and developing through a photomask corresponding to the shape of the contact hole for forming the resist material. Can do.
Examples of the method for applying the resist material include the liquid phase film forming method (coating method) as described above, and one or more of these can be used in combination.

The resist material used may be either a negative resist material or a positive resist material.
As a method for etching the interlayer insulating film 40, for example, a physical etching method, a chemical etching method, or the like as described above can be used.
By the way, when a contact hole is formed and a film formed by a liquid phase film formation method covering the conductor 31 is present, gas due to the solvent remaining in the film is generated. As a result, when the connecting portion is formed in the next step [2-5], this gas is mixed into the connecting portion, causing problems such as deterioration of the characteristics of the connecting portion.
On the other hand, in the interlayer insulating film 40 formed by applying the present invention, the portion covering the conductor 31 is formed by the vapor deposition method. A high connection portion 32 can be formed.

[2-5] Next, a conductive material is supplied to form the connection portion 32 so as to fill the contact hole.
The connection portion 32 first supplies a conductive material so as to fill the contact hole and cover the interlayer insulating film 40, and then removes the conductive material until the upper surface of the interlayer insulating film 40 is exposed. Can be formed.

As the conductive material, the same material as the constituent material of the conductor 31 can be used.
For supplying the conductive material, for example, the dry plating method or the wet plating method as described above can be used.
As a method for removing the conductive material, for example, a physical etching method, a chemical etching method, or the like as described above can be used.

[2-6] Next, the above-described step [2-2] to step [2-5] are further repeated twice to form the multilayer wiring portion 22.
In the present embodiment, the case where the conductor 31 is formed in three layers has been described as an example. However, by appropriately setting the number of times of this step, the number of times the conductor 31 is stacked in the multilayer wiring portion can be set as desired. Can be.

[2-7] Next, the semiconductor element 10 including the ball bumps 52 is placed on the multilayer wiring portion 22 so that the connection portions 32 provided on the upper surface of the multilayer wiring portion 22 and the ball bumps 52 are electrically connected. To be installed.
[2-8] Next, with the cushioning material 61 interposed between the semiconductor element 10 and the cover member 62, the semiconductor element 10 is covered with the cover member 62 and the semiconductor element 10 is sealed with the cover 60. Stop.
The semiconductor device 100 can be obtained through the steps as described above.
The electronic device including the multilayer wiring board 20 of the present invention can be applied to, for example, a liquid crystal display device, an organic EL device, an electro-optical device with a plasma display device, and the like in addition to the semiconductor device 100.

<Electronic equipment>
Further, the semiconductor device 100 (the electronic device of the present invention) as described above can be used in various electronic devices.
FIG. 4 is a perspective view showing a configuration of a mobile (or notebook) personal computer to which the electronic apparatus of the present invention is applied.

In this figure, a personal computer 1100 includes a main body 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display. The display unit 1106 is rotatable with respect to the main body 1104 via a hinge structure. It is supported by.
The personal computer 1100 is built in as a semiconductor element (electronic device) that controls the output signal of the display unit 1106, for example.

FIG. 5 is a perspective view showing a configuration of a mobile phone (including PHS) to which the electronic apparatus of the present invention is applied.
In this figure, a cellular phone 1200 includes a plurality of operation buttons 1202, an earpiece 1204 and a mouthpiece 1206, and a display unit.
The cellular phone 1200 is incorporated as a semiconductor element (electronic device) that controls the output signal of the display unit, for example.

FIG. 6 is a perspective view showing the configuration of a digital still camera to which the electronic apparatus of the present invention is applied. In this figure, connection with an external device is also simply shown.
Here, an ordinary camera sensitizes a silver halide photographic film with a light image of a subject, whereas a digital still camera 1300 photoelectrically converts a light image of a subject with an imaging device such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated.

A display unit is provided on the back of a case (body) 1302 in the digital still camera 1300, and is configured to display based on an imaging signal from the CCD, and functions as a finder that displays an object as an electronic image.
The digital still camera 1300 is built in as a semiconductor element (electronic device) that controls the output signal of the display unit, for example.

A circuit board 1308 is installed inside the case. The circuit board 1308 is provided with a memory that can store (store) an imaging signal.
A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side of the case 1302 (on the back side in the illustrated configuration).
When the photographer or the subject image displayed on the display unit is confirmed and the shutter button 1306 is pressed, the CCD image pickup signal at that time is transferred and stored in the storage device of the circuit board 1308.

  In the digital still camera 1300, a video signal output terminal 1312 and a data communication input / output terminal 1314 are provided on the side surface of the case 1302. As shown in the figure, a television monitor 1430 and a personal computer 1440 are connected to the video signal output terminal 1312 and the data communication input / output terminal 1314 as necessary. Further, the imaging signal stored in the storage device of the circuit board 1308 is output to the television monitor 1430 or the personal computer 1440 by a predetermined operation.

The electronic device of the present invention is, for example, a semiconductor element that controls an input signal from an input device such as a CCD or a data communication input / output terminal 1314 or an output signal to an output device such as a display unit or a video signal output terminal 1312. Built in (electronic device).
In addition to the personal computer (mobile personal computer) in FIG. 4, the mobile phone in FIG. 5, and the digital still camera in FIG. 6, the electronic apparatus of the present invention includes, for example, a television, a video camera, a viewfinder type, Monitor direct-view video tape recorder, laptop personal computer, car navigation system, pager, electronic notebook (including communication function), electronic dictionary, calculator, electronic game device, word processor, workstation, video phone, security TV Monitors, electronic binoculars, POS terminals, devices equipped with touch panels (for example, cash dispensers and automatic ticket vending machines for financial institutions), medical devices (for example, electronic thermometers, blood pressure monitors, blood glucose meters, electrocardiographs, ultrasound diagnostic devices, internal Endoscope display device), fish finder, various measuring instruments, Vessels such (e.g., gages for vehicles, aircraft, and ships), a flight simulator, various monitors, and a projection display such as a projector.

Although the insulating film forming method, multilayer wiring board, electronic device, and electronic apparatus according to the present invention have been described based on the illustrated embodiments, the present invention is not limited thereto.
The insulating film forming method of the present invention can be applied to the case of forming, for example, an interlayer insulating film of a thin film transistor, a gate insulating film, etc. in addition to the interlayer insulating film used in the multilayer wiring board as described above.

Next, specific examples of the present invention will be described.
(Example)
-1- First, a quartz glass substrate (base material) on which a plurality of conductors mainly composed of Al was formed was prepared and washed with pure water.
In addition, the average film thickness of each conductor and the distance of the space between each conductor were 700 nm and 500-3500 nm, respectively.

-2- Next, the pad was impregnated with a material for forming a liquid repellent film in which octadecyltrimethoxysilane was dissolved in toluene so as to be 0.1 wt%.
Then, a liquid repellent film (monomolecular film) composed of octadecyltrimethoxysilane was formed on the upper surface of the conductor by shifting the pad at a constant speed while contacting the pad with the upper surface of the conductor.
The processing conditions for forming the liquid repellent film are as follows.
・ Atmosphere temperature: 25 ℃
・ Pad movement speed: 2mm / sec

-3- Next, the liquid material which melt | dissolved polysilazane in xylene so that it might become 0.5 wt% was selectively supplied to the space between conductors by the inkjet method.
The space was filled with silicon dioxide by heating and drying the liquid material under the following film forming conditions.
・ Atmosphere: In air ・ Atmosphere temperature: 450 ℃
・ Heating time: 15 minutes

-4- Next, the liquid repellent film formed on the upper surface of each conductor was removed using a plasma etching method.
-5- Next, the quartz glass substrate was set in the chamber with the surface on which the conductor was formed facing vertically downward. Then, tetraethoxysilane (TEOS) vapor was supplied together with a carrier gas into the chamber in which the quartz glass substrate was set by a thermal CVD method to obtain a layer mainly composed of silicon dioxide.

Various conditions when tetraethoxysilane is supplied into the chamber by thermal CVD are as follows.
-Flow rate of tetraethoxysilane: 200 sccm
-Carrier gas: Oxygen-Pressure in the chamber during heating: 0.1 Torr
-Temperature in the chamber during heating: 250 ° C
-Heating time: 20 minutes-Mixing ratio of TEOS and oxygen (molar ratio): 1: 2
The flatness (specified in JIS B 0621) of the surface opposite to the quartz glass substrate of the insulating film mainly composed of silicon dioxide obtained as described above is 50 nm and has a substantially flat shape ( It does not require a flattening process such as a chemical mechanical polishing method).

It is a figure (longitudinal sectional drawing) for demonstrating 1st Embodiment of the formation method of an insulating film. It is a longitudinal cross-sectional view which shows the structure of the insulating film formed by 2nd Embodiment of the formation method of an insulating film. It is a longitudinal cross-sectional view which shows embodiment at the time of applying the electronic device of this invention to a semiconductor device. 1 is a perspective view showing a configuration of a mobile (or notebook) personal computer to which an electronic apparatus of the present invention is applied. It is a perspective view which shows the structure of the mobile telephone (PHS is also included) to which the electronic device of this invention is applied. It is a perspective view which shows the structure of the digital still camera to which the electronic device of this invention is applied.

Explanation of symbols

2 ... Substrate 3, 31 ... Conductor 4 ... Insulating film 5 ... Liquid repellent film 41 ... First insulating material 42 ... Second insulating material 43 ... Third insulating material (film) 10 ...... Semiconductor element 20 ...... Multilayer wiring board 30 ...... Space 21 ...... Base substrate 22 ...... Multilayer wiring part 32 ...... Connection part 33 ...... Conductive part 40 ...... Interlayer insulating films 51 and 52 ...... Ball bump 60 ...... ... Cover 61 ... Buffer material 62 ... Cover member 100 ... Semiconductor device 1100 ... Personal computer 1102 ... Keyboard 1104 ... Main body 1106 ... Display unit 1200 ... Mobile phone 1202 ... Operation button 1204 ... Received call Mouth 1206 ... Mouthpiece 1300 ... Digital still camera 1302 ... Case (body) 1304 ... Light receiving unit 1306 ... Shutter button 1 08 ...... circuit board 1312 ...... video signal output terminal 1314 input-output terminal 1430 ...... television monitor 1440 ...... personal computer ...... for data communication

Claims (18)

A method for forming an insulating film for insulating conductors provided on a substrate,
A first step of filling a first insulating material by a liquid phase film forming method so as to fill a space between the conductors;
And a second step of supplying the second insulating material by a vapor deposition method so as to cover each of the conductors and the first insulating material to obtain the insulating film. Method for forming a film.   The method of forming an insulating film according to claim 1, wherein in the first step, the first insulating material is filled so as to be substantially equal to the thickness of the conductor.   The method for forming an insulating film according to claim 1, wherein an ink jet method is used as the liquid phase film forming method in the first step.   4. The method for forming an insulating film according to claim 1, wherein, in the second step, a thermal CVD method or a plasma CVD method is used as the vapor phase film forming method.   5. The method for forming an insulating film according to claim 1, wherein in the second step, the vapor deposition method is performed at an atmospheric temperature lower than a temperature at which the conductor melts.   6. The method for forming an insulating film according to claim 1, wherein the first insulating material and the second insulating material are of the same type.   The method for forming an insulating film according to claim 1, wherein the first insulating material is mainly composed of silicon dioxide.   The method for forming an insulating film according to claim 1, wherein the second insulating material is mainly composed of silicon dioxide.   Prior to the first step, there is a step of performing a liquid repellent treatment for imparting liquid repellency to the liquid material used in the liquid phase film forming method on the surface of the conductor opposite to the base. The method for forming an insulating film according to any one of 1 to 8.   The method for forming an insulating film according to claim 9, further comprising a step of removing the portion subjected to the liquid repellent treatment prior to the second step.   Prior to the first step, a film mainly composed of a third insulating material is formed on the surface of the conductor and the surface of the base material exposed from the conductor by a vapor deposition method. The method for forming an insulating film according to claim 1, further comprising a coating film forming step.   In the film forming step, when the average thickness of the film is C [nm] and the average thickness of the conductor is D [nm], the relationship C / D satisfies 0.02 to 0.2 is satisfied. The method for forming an insulating film according to claim 11, wherein the coating is formed.   The method for forming an insulating film according to claim 11, wherein the third insulating material is the same type as the second insulating material.   The method for forming an insulating film according to claim 11, wherein the third insulating material is mainly composed of silicon dioxide.   The method for forming an insulating film according to any one of claims 1 to 14, wherein the insulating film has a flatness (specified in JIS B 0621) of a surface opposite to the base material of 300 nm or less.   A multilayer wiring board comprising an insulating film formed by the method for forming an insulating film according to claim 1.   An electronic device comprising the multilayer wiring board according to claim 16. An electronic apparatus comprising the electronic device according to claim 17.

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