JPH05339389A - Method for forming polymer film - Google Patents

Abstract

PURPOSE:To realize the formation of a polymer film having specified characteristics by vapor deposition polymerization, by using as the evaporation source materials two monomers for forming the skeleton structure and substances serving as a factor for altering the characteristics. CONSTITUTION:A polymer film is formed by the vapor deposition polymerization wherein two monomers serving as a factor for forming the skeleton structure of the polymer film and at least one auxiliary substance serving as a factor for altering the characteristics of the film are used as the evaporation source materials. The characteristics of the film can be further improved by selecting the combination of the two monomers with the auxiliary substances. This method is used for producing a polymer film for forming the dielectric of a thin-film condensor and can be utilized for producing a thin polymer film having, for example, pyroelectric, piezoelectric or insulating properties.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a polymer film on a substrate by a vapor deposition polymerization method, and more particularly to a method for forming a polymer film used as an insulating film, a moisture-proof film, a lubricating film or the like of electronic parts. ..

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for smaller and lighter electronic devices, and in response to this demand, electronic parts have been downsized. In order to reduce the size and weight of electronic components, a thin film forming method by vapor deposition polymerization using two kinds of monomers as evaporation source materials is used.

For example, there is a capacitor as an example of miniaturization among electronic components. As this capacitor, film-like dielectrics and film-like internal electrodes are alternately laminated, and at least one of the dielectrics is fluorinated or fluoroalkylated, and two monomers having a benzene ring as a skeleton. Thin film capacitor composed of a polymer film formed by vapor deposition polymerization using as a vaporization source material
-50709. ). This thin film capacitor is miniaturized by using a polymer film formed by vapor deposition polymerization as a dielectric.

As a combination of monomers for forming the polymer film, a combination of aromatic diamine and aromatic diisocyanate, a combination of aromatic diamine and aromatic dicarboxylic acid chloride, and a combination of aromatic diamine and aromatic tetraisocyanate are used. There are combinations with carboxylic acids.

When selecting a combination of aromatic diamine and aromatic diisocyanate, a polymer film of fluorinated or fluoroalkylated aromatic polyurea is formed as a dielectric.

When selecting a combination of aromatic diamine and aromatic dicarboxylic acid chloride, a polymer film of fluorinated or fluoroalkylated aromatic polyamide is formed as a dielectric.

When selecting a combination of aromatic diamine and aromatic tetracarboxylic acid, a polymer film of fluorinated or fluoroalkylated aromatic polyimide is formed as a dielectric.

As described above, in the method of forming a polymer film by vapor deposition polymerization, the type of the polymer film and its characteristics are determined by the combination of the monomers. Therefore, a predetermined combination of monomers is selected from a plurality of combinations. By selecting, a polymer film having predetermined properties can be obtained.

[0009]

However, since the kinds of the combination of the monomers are limited, the formation of the polymer film having the predetermined characteristics is restricted due to the restriction of the combination of the monomers, and the two types of the above two kinds are limited. It is difficult to form a polymer film having predetermined characteristics by a vapor deposition polymerization method using a monomer as an evaporation source material.

An object of the present invention is to provide a method for forming a polymer film which can form a polymer film having a predetermined characteristic by a vapor deposition polymerization method.

[0011]

The present invention is a method for forming a polymer film on a substrate, comprising two kinds of monomers which are factors for forming the skeleton structure of the polymer film and the polymer film. By an evaporation polymerization method using as an evaporation source material at least one or more by-products which are factors for changing the characteristics of
The polymer film is formed.

[0012]

[Operation] In the method for forming a polymer film of the present invention, at least two kinds of monomers which are factors for forming a skeleton structure of the polymer film and at least a factor for changing the characteristics of the polymer film. By using one or more auxiliary substances as the evaporation source material, the characteristics of the polymer film are determined by the combination of the two kinds of monomers and the auxiliary substances. Therefore, the two kinds of monomers and the auxiliary substances are used. By selecting the combination with, a polymer film having more excellent properties can be obtained.

[0013]

The method for forming a polymer film of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an example of a thin film capacitor having a dielectric formed by the method for forming a polymer film of the present invention.

The thin film capacitor 1 is, as shown in FIG.
A substrate 2 is provided. The substrate 2 has film-shaped internal electrodes 3a, 3
A laminated structure 5 of b, 3c and film-shaped dielectrics 4a, 4b is formed. Internal electrodes 3a, 3b, 3c and dielectric 4
a and 4b are alternately laminated.

The internal electrodes 3a, 3b, 3c are made of aluminum alloy film, and the film is formed by vapor deposition. The end of the internal electrode 3a and the end of the internal electrode 3c are in electrical contact with each other.

The dielectrics 4a and 4b are composed of a polymer film of fluoroalkylated aromatic polyimide containing a TCNQ complex, and the ends of the dielectrics 4a and 4b are in contact with each other. In this example, N-methylacridinium-7,7,8,8-tetracyanoquinodimethane complex was used as the TCNQ complex.

A fluoroalkylated aromatic polyimide polymer film containing a TCNQ complex comprises 2,2-bis (4-aminophenyl) hexafluoropropane and pyromellitic dianhydride monomers and TCNQ complex crystals. It is formed by a vapor deposition polymerization method used as an evaporation source material. The evaporation amount of the TCNQ complex during vapor deposition was 2,2-
The weight ratio of bis (4-aminophenyl) hexafluoropropane and pyromellitic dianhydride to the fluoroalkylated aromatic polyamic acid obtained by vapor deposition polymerization with each monomer is controlled to be 7%.

The dielectric constant ε of the polymer film of the fluoroalkylated aromatic polyimide containing the TCNQ complex is 30, and the dielectric constant ε of the polymer film of the fluoroalkylated aromatic polyimide alone is 3.5.

The laminated structure 5 includes internal electrodes 3a, 3b, 3c.
Is covered with a protective film 6 so that each of the ends of the
The external electrodes 7 are formed on the exposed end portions of the internal electrodes 3a, 3b, 3c.
Are connected respectively.

As described above, the dielectrics 4a and 4b are connected to the TCNQ.
By using a fluoroalkylated aromatic polyimide polymer film containing a complex, the dielectric constant becomes higher than that of a polymer film of fluoroalkylated aromatic polyimide alone, and it is possible to easily improve the dielectric constant. ..

Next, a method of manufacturing the thin film capacitor will be described with reference to the drawings. 2 is a diagram for explaining a process of forming internal electrodes of the thin film capacitor of FIG.
4A and 4B are views for explaining a process of forming a dielectric of the thin film capacitor of FIG. 1, and FIG. 4 is a view for explaining formation of a laminated structure of the internal electrodes of the thin film capacitor of FIG. 1 and a dielectric. First, as shown in FIG. 2, the pre-cleaned substrate 2 is
The film-shaped internal electrodes 3a made of an aluminum alloy or the like are formed on the surface of the substrate 2 by vapor deposition.

Next, the substrate 2 on which the internal electrodes 3a are formed is sent to the vapor deposition polymerization step. In the vapor deposition polymerization process,
2,2-bis (4-aminophenyl) hexafluoropropane and pyromellitic dianhydride monomers and TC
Crystals of NQ complex are used as an evaporation source material.

As shown in FIG. 2, a polymer film 8 of fluoroalkylated aromatic polyamic acid containing a TCNQ complex is formed on the surface of the internal electrode 3a of the substrate 2 by vapor deposition polymerization. The evaporation amount of the TCNQ complex during vapor deposition is controlled so that the weight ratio to the fluoroalkylated aromatic polyamic acid obtained by vapor deposition polymerization is 7%.

After forming the polymer film 8 of the fluoroalkylated aromatic polyamic acid, the substrate 2 on which the internal electrode 3a and the polymer film 8 of the fluoroalkylated aromatic polyamic acid are formed is sent to the heat dehydration step. In the heating and dehydrating step, a heating operation is performed on the polymer film 8 of the fluoroalkylated aromatic polyamic acid. The heating causes ring closure of the fluoroalkylated aromatic polyamic acid, and the dehydration accompanying the ring closure changes the polymer film 8 of the fluoroalkylated aromatic polyamic acid to a polymer film of the fluoroalkylated aromatic polyimide.

Then, the vapor deposition step, the vapor deposition polymerization step, and the heat dehydration step are sequentially repeated a predetermined number of times. As shown in FIG. 4, a laminated structure 5 of internal electrodes 3a, 3b, 3c and dielectrics 4a, 4b made of a polymer film of fluoroalkylated aromatic polyimide is formed on the substrate 2.

Then, a thin film capacitor 1 having a high dielectric constant is obtained as shown in FIG. 1 through a protective film attaching step and an external electrode forming step.

In this embodiment, 2,2-bis (4-
Aminophenyl) hexafluoropropane and pyromellitic dianhydride monomers and crystals of TCNQ complex are used as evaporation source materials, but other combinations can be used instead of this combination.

Other combinations include a combination of aromatic diamine and aromatic diisocyanate monomers with a TCNQ complex, and a combination of aromatic diamine and aromatic dicarboxylic acid chloride monomers with a TCNQ complex.

When selecting the former combination, a polymer film of a fluorinated or fluoroalkylated aromatic polyurea containing a TCNQ complex is formed as a dielectric.

When the latter combination is chosen, a polymer film of fluorinated or fluoroalkylated aromatic polyamide containing TCNQ complex is formed as a dielectric.

The polymer film forming method of the present invention is applied to the formation of a polymer film constituting a dielectric of a thin film capacitor. For example, a high film having a pyroelectric property, a piezoelectric property or an insulating property is used. It can also be applied to the formation of a molecular thin film.

[0032]

As described above, according to the method for forming a polymer film of the present invention, a polymer having more excellent properties can be obtained by selecting a combination of the two kinds of monomers and the sub-substances. A film can be formed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an example of a thin film capacitor in which a dielectric is formed by a method for forming a polymer film of the present invention.

FIG. 2 is a diagram for explaining a process of forming internal electrodes of the thin film capacitor of FIG.

3A and 3B are views for explaining a process of forming a dielectric body of the thin film capacitor of FIG.

FIG. 4 is a diagram for explaining the formation of a laminated structure of the internal electrodes of the thin film capacitor of FIG. 1 and a dielectric.

[Explanation of symbols]

 1 Thin Film Capacitor 2 Substrate 3a, 3b, 3c Internal Electrode 4a, 4b Dielectric 5 Laminated Structure 8 Fluoroalkylated Aromatic Polyamic Acid Polymer Film

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C23C 14/12 9271-4K H01B 3/18 9059-5G H01G 4/06 9375-5E 4/30 8019 -5E H01L 29/28 (72) Shoichi Nozoe, Shoichi Nozoe, 1-1, Higashi, Tsukuba-shi, Ibaraki Institute of Industrial Science and Technology (72) Inventor Mikio Suzuki 2932 Motooshima, Matsukawa-cho, Shimoina-gun, Nagano Rubycon Electronics (72) Inventor Yoshiro Shinoda 2932 Motooshima, Matsukawa-cho, Shimoina-gun, Nagano Rubycon Electronics Co., Ltd. (72) Inventor Masahide Miyagai 2932 Motooshima, Matsukawa-cho, Shimoina-gun, Nagano Rubycon Electronics Co., Ltd.

Claims (8)

[Claims] 1. A method for forming a polymer film on a substrate, comprising two kinds of monomers which are factors for forming a skeleton structure of the polymer film and a factor for changing the characteristics of the polymer film. A method for forming a polymer film, characterized in that the polymer film is formed by a vapor deposition polymerization method using at least one or more of the sub-substances as an evaporation source. 2. The method for forming a polymer film according to claim 1, wherein the polymer film is made of a fluorinated or fluoroalkylated aromatic polyurea containing the by-product. 3. The method for forming a polymer film according to claim 1, wherein the polymer film is made of a fluorinated or fluoroalkylated aromatic polyamide containing the by-product. 4. The method for forming a polymer film according to claim 1, wherein the polymer film is made of a fluorinated or fluoroalkylated aromatic polyimide containing the sub-substance. 5. The method for forming a polymer film according to claim 1, wherein one of the monomers is an aromatic diamine and the other monomer is an aromatic diisocyanate. 6. The method for forming a polymer film according to claim 1, wherein one of the monomers is an aromatic diamine and the other monomer is an aromatic dicarboxylic acid chloride. 7. The method for forming a polymer film according to claim 1, wherein one of the monomers is an aromatic diamine and the other monomer is an aromatic tetracarboxylic acid. 8. The method for forming a polymer film according to claim 1, wherein the secondary substance is a TCNQ complex.