JP2006190915A - Method of forming insulation film, electronic device, substrate therefor and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of forming an insulation film by which an insulation film having a low dielectric constant and a high mechanical strength can be easily manufactured at a low cost; and to provide a substrate for an electronic device which includes the insulation film formed by the method, an electronic device including the substrate for an electronic device, and an electronic apparatus. <P>SOLUTION: A multilayer wiring board 1 includes a substrate 2, first wiring pattern 3 formed on the substrate 2, first insulation film 4 so formed as to cover the first wiring pattern 3, second wiring pattern 5 formed on the first insulation film 4, and second insulation film 6 so formed as to cover the second wiring pattern 5. The insulation films 4 and 6 are obtained by the insulation film formation method comprising a first process wherein silicone oil is gasified, and a second process wherein a polymer obtained by plasma polymerization of the gasified silicone oil is deposited to form the insulation film mainly formed of the polymer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an insulating film forming method, an electronic device substrate, an electronic device, and an electronic apparatus.

Conventionally, a silica (SiO ₂ ) film formed by a CVD method or the like is frequently used as an interlayer insulating film in a semiconductor integrated circuit or the like.
However, with the high integration of semiconductor integrated circuits and the like, an increase in signal delay resulting from an increase in inter-wiring capacitance between conductor patterns has hindered high performance of semiconductor integrated circuits.
Therefore, in order to suppress the signal delay, it is necessary to reduce the resistance of the conductor pattern and the inter-wiring capacitance.

As a method for reducing the inter-wiring capacitance, it is conceivable to lower the relative dielectric constant of the interlayer insulating film formed between the conductor patterns.
However, in the conventional interlayer insulating film made of silica, since the relative dielectric constant of silica itself is as high as 4.0 to 4.2, there is a limit in reducing the relative dielectric constant of the interlayer insulating film.
Therefore, the use of an organic insulating film has been studied as another method for reducing the capacitance between wirings (see, for example, Patent Document 1).

Patent Document 1 contains (A) 30 to 100 mol% of a structural unit (T unit) represented by R ¹ —SiZ ₃ , and among these T units, R ¹ —Si (OH) Z ′ ₂ 30 to 80 mol% of a structural unit (T-2 unit) containing one silanol group represented by the formula (wherein R ¹ is a monovalent hydrocarbon group, Z is an OH group, a hydrolyzable group and a siloxane) Selected from residues, at least one is a siloxane residue, Z ′ is a siloxane residue), a silanol group-containing silicone resin having a number average molecular weight of 100 or more, and (B) an acrylic ester, a methacrylic ester or Disclosed is a method for obtaining an organic insulating film by heating a silicone-containing film-forming composition containing a polymer obtained by polymerizing monomers containing these mixtures at a temperature equal to or higher than the decomposition temperature of (B). Yes.
However, the organic insulating film obtained by this method has a problem that the manufacturing process is complicated and the manufacturing cost is high, or that the organic insulating film is porous and the mechanical strength is low.

JP 2002-212503 A

  An object of the present invention is to provide a method for forming an insulating film that can easily and inexpensively form an insulating film having a low relative dielectric constant and excellent mechanical strength, and an electronic device including an insulating film formed by the method for forming such an insulating film. An object of the present invention is to provide a substrate, an electronic device and an electronic apparatus including the electronic device substrate.

Such an object is achieved by the present invention described below.
The insulating film forming method of the present invention includes a first step of vaporizing silicone oil,
And a second step of depositing a polymer obtained by plasma polymerization of vaporized silicone oil to form an insulating film mainly composed of the polymer.
Thereby, an insulating film having a low relative dielectric constant and excellent mechanical strength can be easily and inexpensively formed.

In the method for forming an insulating film of the present invention, the silicone oil preferably has a weight average molecular weight of 100 to 500.
Thereby, the silicone oil can be easily vaporized in the first step. Moreover, since the silicone oil having such a weight average molecular weight has an appropriate fluidity, it can be easily handled.

In the method for forming an insulating film of the present invention, the second step is preferably performed in a reduced pressure state.
Thereby, plasma polymerization reaction can be advanced easily.
In the method for forming an insulating film of the present invention, the degree of vacuum in the reduced pressure state is preferably 0.1 to 500 Pa.
Thereby, the plasma polymerization reaction can be easily advanced, and the insulating film can be formed at a lower cost.

In the method for forming an insulating film of the present invention, the relative permittivity of the insulating film is adjusted by setting the composition of the silicone oil and / or the plasma polymerization treatment condition in the second step to a predetermined condition. It is preferable.
Thereby, the relative dielectric constant of the obtained insulating film can be adjusted to a desired value.
In the insulating film forming method of the present invention, the predetermined condition is preferably at least one of atmospheric pressure, atmospheric temperature, high frequency output, vaporized oil flow rate, and vaporized oil concentration.
Thereby, the relative dielectric constant of the obtained insulating film can be adjusted to a desired value more easily and reliably.

In the method for forming an insulating film of the present invention, it is preferable that a post-processing step of adjusting a relative dielectric constant of the insulating film is provided after the second step.
Thereby, the relative dielectric constant of the insulating film can be adjusted.
In the method for forming an insulating film of the present invention, the post-processing step is performed by at least one of an ultraviolet irradiation process for irradiating the insulating film with ultraviolet rays and a heating process for heating the insulating film. Is preferred.
Thereby, the dielectric constant of an insulating film can be adjusted easily and reliably.

The substrate for electronic devices of the present invention comprises a substrate,
A conductor pattern provided on the substrate;
And an insulating film formed by the method of forming an insulating film of the present invention so as to cover the conductor pattern on the substrate.
As a result, it is possible to easily and inexpensively obtain an electronic device substrate in which the inter-wiring capacitance generated in the conductor pattern or between the conductor patterns is reduced, and the signal delay in the conductor pattern is suitably reduced.

The substrate for electronic devices of the present invention comprises a substrate,
A conductor pattern provided on the substrate;
An electronic device substrate comprising an insulating film formed on the substrate so as to cover the conductor pattern,
The insulating film is mainly composed of a polymer obtained by plasma polymerization of silicone oil.
As a result, it is possible to easily and inexpensively obtain an electronic device substrate in which the inter-wiring capacitance generated in the conductor pattern or between the conductor patterns is reduced, and the signal delay in the conductor pattern is suitably reduced.

In the electronic device substrate of the present invention, the insulating film preferably has a relative dielectric constant of 2 or less.
This reduces the inter-wiring capacitance that occurs in and between conductor patterns on the substrate for electronic devices, and makes signal delays in the conductor pattern more effective even when the conductor patterns are densely integrated. Can be reduced.

In the electronic device substrate of the present invention, it is preferable that the insulating film is dense.
Thereby, the mechanical strength, thermal conductivity, and moisture absorption resistance of the insulating film obtained can be improved.
In the electronic device substrate of the present invention, the insulating film preferably has a porosity of less than 5%.
Thereby, the mechanical strength, thermal conductivity, and moisture absorption resistance of the obtained insulating film can be further improved.

In the electronic device substrate of the present invention, the insulating film preferably has an average thickness of 0.3 to 2 μm.
As a result, it is possible to more reliably prevent the inter-wiring capacitance of the obtained insulating film from increasing, and to prevent the entire thickness of the electronic device substrate from becoming unnecessarily thick.

The electronic device of the present invention includes the electronic device substrate of the present invention.
As a result, the signal delay of the conductor pattern due to high integration is more effectively reduced, and the electronic device can be driven at a high speed and the reliability thereof is high.
An electronic apparatus according to the present invention includes the electronic device according to the present invention.
Thereby, an electronic device with high reliability is obtained.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an insulating film forming method, an electronic device substrate, an electronic device and an electronic apparatus according to the present invention will be described in detail with reference to the accompanying drawings.
Below, the case where the board | substrate for electronic devices of this invention is applied to a multilayer wiring board is demonstrated as a representative.
FIG. 1 is a longitudinal sectional view showing an embodiment of a multilayer wiring board to which an electronic device substrate of the present invention is applied. FIG. 2 is a diagram for explaining a method for manufacturing the multilayer wiring board shown in FIG. ). In the following description, the upper side in FIGS. 1 and 2 is referred to as “upper” and the lower side is referred to as “lower”.

  A multilayer wiring board 1 shown in FIG. 1 includes a substrate 2, a first wiring pattern (first conductor pattern) 3 including wirings 31 and 32 provided on the substrate 2 at a predetermined distance, A second wiring pattern (second wiring) including a first insulating film 4 provided to cover the wiring pattern 3 and wirings 51 and 52 provided on the first insulating film 4 at a predetermined distance from each other. And a second insulating film 6 provided to cover the second wiring pattern 5.

The substrate 2 is made of, 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.
In addition, by using a resin material having flexibility as a constituent material of the substrate 2, flexibility can be imparted to the entire multilayer wiring substrate 1.
Moreover, although the average thickness of the board | substrate 2 is not specifically limited, It is preferable that it is about 20-2000 micrometers, and it is more preferable that it is about 30-1000 micrometers. By setting the average thickness of the substrate 2 within the above range, it is possible to ensure the mechanical strength of the entire multilayer wiring substrate 1 and to prevent the entire thickness of the multilayer wiring substrate 1 from becoming unnecessarily thick. .

The first wiring pattern 3 and the second wiring pattern 5 are each composed of, for example, Au, Ag, Pt, Cu, Ni, Al, or an alloy containing these.
Each average thickness of the first wiring pattern 3 and the second wiring pattern 5 varies depending on the resistivity of these constituent materials, but is preferably about 0.1 to 3 μm, preferably about 0.3 to 2 μm. It is more preferable that If the average thickness of each of the first wiring pattern 3 and the second wiring pattern 5 is smaller than the lower limit value, the amount of heat generated from the wiring pattern increases and the reliability of the multilayer wiring board 1 may be reduced. . On the other hand, if the average thickness is larger than the upper limit value, the total thickness of the multilayer wiring board 1 becomes excessively larger than necessary, and the electronic devices and electronic devices to which the multilayer wiring board 1 is applied are downsized (thinned). It is disadvantageous.

The first insulating film 4 and the second insulating film 6 are each composed mainly of a polymer obtained by plasma polymerization of silicone oil.
The insulating film forming method of the present invention is applied to the formation of these insulating films 4 and 6.
The relative dielectric constants of the insulating films 4 and 6 are each preferably 2 or less, and more preferably 1.5 or less. As a result, the inter-wiring capacitance between the first wiring pattern 3 and the second wiring pattern 5, the space between the wiring 31 and the wiring 32 (in the first wiring pattern 3), and the wiring 51 and the wiring 52 It is possible to reduce the inter-wiring capacitance between the spaces (in the second wiring pattern 5). Therefore, even when the wirings of the multilayer wiring board 1 are integrated with high density, the signal delay in the first wiring pattern 3 and the second wiring pattern 5 can be reduced more effectively.

Each of the insulating films 4 and 6 may be either dense or porous, but is preferably dense. Thereby, since the mechanical strength of each insulating film 4 and 6 can be improved, in the polishing process as will be described later, between the first insulating film 4 and the substrate 2 and between each insulating film 4 and 6. Can be prevented from peeling at the bonding interface.
In this case, the porosity of each of the insulating films 4 and 6 is preferably less than 5%, and more preferably less than 3%. Thereby, the said effect can be improved more.

  The average thickness of each of the insulating films 4 and 6 is preferably about 0.3 to 2 [mu] m, and more preferably about 0.5 to 1.2 [mu] m. As a result, it is possible to more reliably prevent an increase in inter-wiring capacitance within each wiring pattern 3, 5 and between each wiring pattern 3, 5. Moreover, since it is possible to prevent the thickness of the entire multilayer wiring board 1 from becoming unnecessarily thick, it is possible to prevent an electronic device or electronic apparatus to which the multilayer wiring board 1 is applied from being enlarged.

Such a multilayer wiring board 1 can be manufactured as follows, for example.
[1] First, as shown in FIG. 2A, the first wiring pattern 3 is formed on the upper surface of the substrate 2.
The first wiring pattern 3 can be formed, for example, by forming a metal film so as to cover the upper surface of the substrate 2 and then removing unnecessary portions of the metal film.

For the formation of the metal film, for example, chemical vapor deposition (CVD) such as plasma CVD, thermal CVD, laser CVD, vacuum deposition, sputtering (low temperature sputtering), dry plating methods such as ion plating, electrolytic plating, electroless In addition to wet plating methods such as plating, thermal spraying methods, sol-gel methods, MOD methods, etc., bonding of metal foils and the like can be used.
Further, as a method for removing the metal film, for example, one or two of a physical etching method such as plasma etching, reactive ion etching, beam etching, and light assisted etching, and a chemical etching method such as wet etching are used. A combination of the above can be used.

[2] Next, as shown in FIG. 2B, a first insulating film 4 is formed on the substrate 2 so as to cover the first wiring pattern 3.
The insulating film forming method of the present invention is applied to the formation of the first insulating film 4. The insulating film forming method of the present invention is characterized in that silicone oil is used as a raw material. Since silicone oil is inexpensive and easily available, it is possible to reduce the manufacturing cost of the first insulating film 4 and thus reduce the manufacturing cost of the multilayer wiring board 1.

[2-1] First, the silicone oil is vaporized (first step).
Examples of the method for vaporizing the silicone oil include methods such as heater heating, infrared irradiation, and application of ultrasonic waves, and one or more of them can be used in combination.
As the silicone oil, it is preferable to use one that is easily vaporized, that is, one having a small molecular weight. Since those having a low molecular weight are sufficiently vaporized at room temperature without a special vaporization system, the equipment cost can be reduced. The vaporized oil may be used as it is or diluted with a carrier gas and introduced into the vacuum chamber.

Specifically, the weight average molecular weight of the silicone oil is preferably about 100 to 500. A silicone oil having a weight average molecular weight within the above range has a relatively low boiling point, and can be easily vaporized by the method described above. Moreover, since the silicone oil of such a weight average molecular weight has moderate fluidity | liquidity, handling of silicone oil is easy.
Examples of such silicone oils include dimethyl silicone oil, methylphenyl silicone oil, methyl hydrogen silicone oil, and modified products in which various functional groups are introduced. A combination of more than one species can be used.

Examples of the modified products include epoxy-based modified products, alkyl-based modified products, amino-based modified products, carboxyl-based modified products, alcohol-based modified products, fluorine-based modified products, alkyl-aralkyl polyether-based modified products, epoxy Examples include polyether-based modified products and polyether-based modified products.
Among these, as the silicone oil, it is particularly preferable to use a dimethyl silicone oil or a modified product thereof as a main component. Dimethyl silicone oil or a modified product thereof is preferable because it easily causes a polymerization reaction by plasma, and is particularly preferable because it is inexpensive and easily available.
It should be noted that the relative dielectric constant of the first insulating film 4 can be adjusted to a desired value by appropriately setting the composition (for example, type, combination, ratio) of the silicone oil to be used.

[2-2] Next, the vaporized silicone oil is introduced into the vacuum chamber and plasma polymerized. Thereby, a polymer of silicone oil is obtained, and this polymer is deposited on the substrate 2 so as to cover the first wiring pattern 3 to obtain the first insulating film 4 mainly composed of this polymer ( Second step).
The vacuum chamber is connected to a vacuum pump for exhausting the vacuum chamber and piping for introducing vaporized silicone oil. Further, the piping is provided with a heating mechanism for variably controlling the introduction amount of the vaporized silicone oil and a heating mechanism so that the vaporized oil does not condense again as necessary.
In addition to these, the vacuum chamber includes an electrode for generating plasma, a stage for mounting the substrate 2, a heater for heating the substrate 2, a chiller for controlling the atmospheric temperature in the vacuum chamber, and the substrate 2. Each is provided with an ultraviolet lamp for irradiating ultraviolet rays.

Vaporized silicone oil, that is, silicone oil molecules, is turned into plasma by applying voltage in the vacuum chamber, and the plasmaized silicone oil molecules collide with each other to cause a polymerization reaction. As a result, a silicone oil polymer (polyorganosiloxane) is produced.
At this time, the plasma polymerization processing conditions (film formation conditions) are set to predetermined conditions, or the plasma polymerization processing conditions are set to predetermined conditions together with the silicone oil composition as described above, to thereby achieve the first condition. The relative dielectric constant of the insulating film 4 can be adjusted to a desired value.

There are various plasma polymerization processing conditions (predetermined conditions) to be set, and at least one of atmospheric pressure, atmospheric temperature, high frequency output, vaporized oil flow rate, and vaporized oil concentration is used. Is preferred. By setting these conditions, the relative dielectric constant of the first insulating film 4 can be adjusted more easily and reliably.
The predetermined condition is appropriately determined according to the target relative dielectric constant, and can be, for example, as follows.

The atmospheric pressure during the plasma polymerization may be atmospheric pressure, but is preferably a reduced pressure state (less than atmospheric pressure). By setting the atmospheric pressure to a reduced pressure state, the plasma polymerization reaction can easily proceed.
In this case, the degree of vacuum is preferably about 0.1 to 500 Pa. Even if the degree of vacuum is increased beyond the above range, the film formation rate is slow, and an expensive vacuum pump is required. On the other hand, when the degree of vacuum is lower than the above range, the polymerization reaction may not proceed sufficiently.

The atmospheric temperature during the plasma polymerization is preferably about 30 to 90 ° C. When the ambient temperature is within the above range, the silicone oil molecules can be efficiently converted into plasma, and as a result, the first insulating film 4 can be obtained efficiently.
The high frequency output during plasma polymerization is preferably about 0.1 to 3 W / cm ² . If the high-frequency output is lower than the lower limit value, depending on the ambient temperature or the like, molecules of silicone oil cannot be efficiently converted into plasma, and it may take a long time to form the first insulating film 4. On the other hand, even if the high-frequency output is increased beyond the upper limit, an improvement in the deposition rate of the first insulating film 4 cannot be expected.
The vaporized oil flow rate during plasma polymerization is preferably set to an optimum amount according to the volume of the vacuum chamber.
The vaporized oil concentration during plasma polymerization is preferably set to an optimum concentration between 1 and 100%.

[2-3] Next, a post-processing step for adjusting the relative dielectric constant of the first insulating film 4 is performed.
In this post-treatment, for example, the ratio of the obtained first insulating film 4 is obtained when the first insulating film 4 is formed so as to have the target relative dielectric constant in the steps up to the step [2-2]. The fine adjustment when the dielectric constant slightly deviates from the target value, the composition of the silicone oil and the plasma polymerization treatment conditions in the steps up to the step [2-2] are mainly focused on the reduction of the manufacturing cost. After the first insulating film 4 is formed, the relative dielectric constant is adjusted (mainly adjusted) to a target value.

  This post-treatment may be any method as long as the relative dielectric constant of the first insulating film 4 can be adjusted, but the ultraviolet irradiation treatment for irradiating the first insulating film 4 with ultraviolet rays and the first treatment. The heat treatment is preferably performed by at least one of the heat treatments for heating one insulating film 4. According to this method, the relative dielectric constant of the first insulating film 4 obtained in the step [2-2] can be easily and reliably adjusted.

Next, each of these post-processing will be described.
[2-3-1] Ultraviolet irradiation treatment The wavelength of ultraviolet rays used in the ultraviolet irradiation treatment may be 400 nm or less.
The intensity | strength (irradiation amount) of an ultraviolet-ray is set suitably according to the composition of a silicone oil, and the target dielectric constant, and is not specifically limited.
In addition, it is preferable that the atmosphere which performs an ultraviolet irradiation process shall be air | atmosphere or arbitrary gas atmosphere.

[2-3-2] Heat treatment The temperature of the heat treatment is not particularly limited, but is preferably about 200 to 500 ° C.
Also, the heat treatment time is not particularly limited, but is preferably about 10 to 900 seconds when the heat treatment temperature falls within the above range.
Further, by performing the heat treatment, the adhesion between the first insulating film 4 and the substrate 2 can be improved.
This post-treatment step may be performed as necessary, and may be omitted if the first insulating film 4 having a target relative dielectric constant can be obtained in the step [2-2].

[3] Next, as shown in FIG. 2 (c), the surface of the first insulating film 4 is planarized by reducing the irregularities.
This can be performed, for example, by chemical mechanical polishing (CMP), sputtering, plasma treatment, or the like.
For example, in chemical mechanical polishing, the surface of the object to be polished is pressed vertically against the polishing pad, and one or both of them are rotated, and the surface is flattened using chemical and mechanical actions. Turn into. At this time, a shear stress is generated at the bonding interface between the first insulating film 4 and the substrate 2.

By making the first insulating film 4 dense, it is possible to increase the adhesion between the first insulating film 4 and the substrate 2 and the resistance to stress as described above. Therefore, even when the above-described shear stress is generated, it is possible to effectively prevent the first insulating film 4 from being peeled off from the substrate 2 and the occurrence of defects such as cracks in the first insulating film 4. can do.
According to the method for forming an insulating film of the present invention, a dense film can be easily obtained as the first insulating film 4.

[4] Next, as shown in FIG. 2D, the second wiring pattern 5 including the wirings 51 and 52 is formed on the first insulating film 4 in the same manner as in the step [1]. Form.
[5] Next, as shown in FIG. 2E, in the same manner as in the step [2], the second insulating film 4 is covered with the second insulating film 4 so as to cover the second wiring pattern 5. A film 6 is formed.
[6] Next, if necessary, the surface of the second insulating film 6 is planarized by reducing the irregularities in the same manner as in the step [3].
Through the above steps, the multilayer wiring board 1 is obtained.

According to this method, the first insulating film 4 and the second insulating film 6 can be formed easily and inexpensively using a silicone oil that is relatively inexpensive and easy to handle. For this reason, it is possible to reduce the manufacturing cost of each of the insulating films 4 and 6, and consequently to reduce the manufacturing cost of the entire multilayer wiring board 1.
In addition, since an insulating film having a low relative dielectric constant can be obtained, the inter-wiring capacitance generated between the wirings 31 and 32 and between the wirings 51 and 52 (in each wiring pattern 3 and 5) of the multilayer wiring board 1, and The inter-wiring capacitance generated between the wiring patterns 3 and 5 can be reduced, and the signal delay in each wiring pattern 3 and 5 can be suitably reduced.

<Electronic device>
The multilayer wiring board (electronic device substrate of the present invention) 1 as described above can be applied to various electronic devices.
FIG. 3 is a plan view showing a configuration of a static random access memory (SRAM) to which the electronic device of the present invention is applied.

An SRAM (electronic device of the present invention) 100 shown in FIG. 3 includes a memory cell array 101, an address buffer 102, a row decoder 103, a word driver 104, an address buffer 105, a column decoder 106, a column selection switch 107, and an input / output circuit 108. And a circuit such as a control circuit 109.
Each of the circuits 101 to 109 is provided on the multilayer wiring board 1 described above, and predetermined ones are electrically connected via the first wiring pattern 3 and / or the second wiring pattern 5. .

As described above, in the multilayer wiring board 1, the wiring capacity between the wiring patterns 3, 5 and between the wiring patterns 3, 5 can be reduced, so that each circuit 101 to 109 is connected to each other. The signal delay in the wiring patterns 3 and 5 is effectively reduced.
Further, as described above, by making the insulating films 4 and 6 dense, the thermal conductivity of the entire multilayer wiring board 1 can be improved. In the SRAM 100, the heat generated from the wiring is efficiently transferred to the outside. Can be released.
Moreover, by making each insulating film 4 and 6 dense, each insulating film 4 and 6 has a small surface area in contact with moisture in the atmosphere, and has excellent moisture absorption resistance. As a result, an increase in the dielectric constant associated with moisture absorption of the insulating films 4 and 6 can be prevented.

The SRAM 100 provided with such a multilayer wiring board 1 can more effectively reduce the signal delay of each wiring pattern due to high integration, and the SRAM 100 can be driven at a high speed and has high reliability.
In the SRAM 100, when an insulating film (an interlayer insulating film, an inter-element isolation film, etc.) provided in each circuit 101 to 109 or between each circuit 101 to 109 is formed, the insulating film of the present invention is formed. A method may be applied.

<Electronic equipment>
The SRAM (electronic device of the present invention) as described above can be applied to 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 electronic device of the present invention is incorporated as a storage device for temporarily storing (storing) an input signal from an input device such as a keyboard 1102 or an output signal to an output device such as a display unit 1106, for example. Yes.

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 electronic device of the present invention temporarily stores, for example, input signals from input devices such as a plurality of operation buttons 1202 and the mouthpiece 1206, output signals to output devices such as the earpiece 1204 and the display unit, and the like ( It is built in as a storage device.

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.
A circuit board 1308 is installed inside the case. The circuit board 1308 is provided with the electronic device of the present invention as a storage device capable of storing (storing) 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 temporarily stores, for example, 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. It functions as a storage device that stores (stores).
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, electronic device substrate, electronic device, and electronic apparatus of 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.
1. Formation of insulating film (Example 1)
First, a vacuum chamber in which a vaporizer was connected by piping was prepared, a silicon substrate was placed on an internal stage, and then the inside of the vacuum chamber was depressurized using an exhaust pump.
Next, dimethyl silicone oil was supplied to the vaporizer to vaporize the dimethyl silicone oil.
A dimethyl silicone oil having a weight average molecular weight of 100 to 300 was used.

Next, the vaporized dimethyl silicone oil was introduced into the vacuum chamber through a pipe.
Then, dimethyl silicone oil was plasma-polymerized to deposit the obtained polymer on the silicon substrate to form an insulating film.
In addition, the process conditions in plasma polymerization are as showing below.
・ Degree of vacuum: 1-50 Pa
・ Atmosphere temperature: 40 ℃
・ High frequency output: 0.1 to 1 W / cm ²
・ Vaporized oil flow rate: 10-500sccm
-Vaporized oil concentration: 10-90 vol%
The average thickness of the obtained insulating film was 1 μm.

(Example 2)
An insulating film was formed in the same manner as in Example 1 except that dimethyl silicone oil having a weight average molecular weight of 300 to 500 was used and the plasma polymerization treatment conditions were as follows.
・ Degree of vacuum: 1-50 Pa
・ Atmosphere temperature: 70 ℃
・ High frequency output: 0.5 to 3 W / cm ²
・ Vaporized oil flow rate: 10-500sccm
-Vaporized oil concentration: 10-90 vol%
The average thickness of the obtained insulating film was 1 μm.

(Example 3)
An insulating film was formed in the same manner as in Example 1, and the obtained insulating film was subjected to heat treatment (post treatment).
The heat treatment conditions were set as follows.
Heating temperature: 200-400 ° C
Heating time: 60 to 300 seconds The average thickness of the obtained insulating film was 0.95 μm.

2. Evaluation The porosity and relative dielectric constant of the insulating film obtained in each example were measured.
The porosity was measured using an X-ray small angle scattering method.
The relative dielectric constant was measured using a mercury probe method.
These results are shown in Table 1.

As shown in each example of Table 1, the dielectric constant of the insulating film is adjusted by setting the silicone oil composition and / or plasma polymerization treatment conditions to predetermined conditions and adding a post-treatment step. It became clear to get.
In addition, when the insulating film was formed in the same manner as described above by changing the composition of the silicone oil and the processing conditions of the plasma polymerization to conditions other than those shown in this example, the relative dielectric constant was the value shown in Table 1. It was possible to adjust from. The obtained insulating films were all dense with a porosity of less than 5%.

It is a longitudinal cross-sectional view which shows embodiment of a multilayer wiring board. It is a figure (longitudinal sectional drawing) for demonstrating the manufacturing method of the multilayer wiring board shown in FIG. It is a top view which shows the structure of static RAM (SRAM) to which the electronic device of this invention is applied. 1 is a perspective view illustrating a configuration of a mobile 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

  DESCRIPTION OF SYMBOLS 1 ... Multilayer wiring board 2 ... Board 3 ... 1st wiring pattern 31, 32 ... Wiring 4 ... 1st insulating film 5 ... 2nd wiring pattern 51, 52 ... Wiring 6 ... 1st 2. Insulating film 100 ... SRAM 101 ... Memory cell array 102 ... Address buffer 103 ... Row decoder 104 ... Word driver 105 ... Address buffer 106 ... Column decoder 107 ... Column selection switch 108 ... Input / output Circuit 109 ... Control circuit 1100 ... Personal computer 1102 ... Keyboard 1104 ... Main body 1106 ... Display unit 1200 ... Mobile phone 1202 ... Operation buttons 1204 ... Earpiece 1206 ... Mouthpiece 1300 ... Digital Still camera 1302 …… Case 1304 …… Light receiving unit 13 06 …… Shutter button 1308 …… Circuit board 1312 …… Terminal 1314 …… Terminal 1430 …… TV monitor 1440 …… Personal computer

Claims (16)

A first step of vaporizing silicone oil;
And a second step of depositing a polymer obtained by plasma polymerization of vaporized silicone oil to form an insulating film mainly composed of the polymer.   The method of forming an insulating film according to claim 1, wherein the silicone oil has a weight average molecular weight of 100 to 500.   The method for forming an insulating film according to claim 1, wherein the second step is performed in a reduced pressure state.   The method for forming an insulating film according to claim 3, wherein the degree of vacuum in the reduced pressure state is 0.1 to 500 Pa.   5. The relative dielectric constant of the insulating film is adjusted by setting the composition of the silicone oil and / or the plasma polymerization treatment condition in the second step to a predetermined condition. 6. Of forming an insulating film.   6. The method for forming an insulating film according to claim 1, wherein the predetermined condition is at least one of atmospheric pressure, atmospheric temperature, high-frequency output, vaporized oil flow rate, and vaporized oil concentration.   The method for forming an insulating film according to claim 1, further comprising a post-processing step of adjusting a relative dielectric constant of the insulating film after the second step.   The method of forming an insulating film according to claim 7, wherein the post-processing step is performed by at least one of an ultraviolet irradiation process for irradiating the insulating film with ultraviolet rays and a heating process for heating the insulating film. . A substrate,
A conductor pattern provided on the substrate;
An electronic device substrate comprising: an insulating film formed by the method for forming an insulating film according to claim 1 so as to cover the conductor pattern on the substrate. A substrate,
A conductor pattern provided on the substrate;
An electronic device substrate comprising an insulating film formed on the substrate so as to cover the conductor pattern,
The substrate for electronic devices, wherein the insulating film is mainly composed of a polymer obtained by plasma polymerization of silicone oil.   The electronic device substrate according to claim 9, wherein the insulating film has a relative dielectric constant of 2 or less.   The electronic device substrate according to claim 9, wherein the insulating film is dense.   The electronic device substrate according to claim 12, wherein the insulating film has a porosity of less than 5%.   The substrate for electronic devices according to claim 9, wherein the insulating film has an average thickness of 0.3 to 2 μm.   An electronic device comprising the electronic device substrate according to claim 9.   An electronic apparatus comprising the electronic device according to claim 15.

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