JPH0626704B2 - Ultra thin film with improved adhesion to substrate and its manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heat-resistant polymer ultra-thin film having improved adhesion to a substrate and a method for producing the same, and more specifically, to a surface treatment for improving the adhesion. An ultra thin film formed by accumulating a heat resistant polymer or its precursor on a substrate by the Langmuir-Blodgett method (hereinafter referred to as LB method) and forming a heat resistant polymer if necessary in the case of a precursor , Electronic devices, etc.
It is used as various composite articles.

Conventional technology Already in the 1930s, it was found by Langmuir and Blodgett that fatty acids having about 16 to 22 carbon atoms form a monomolecular film on the surface of water, and it can be accumulated on a substrate. It has only recently started.

For an overview of previous research, see Solid State Physics 17 (12) 45 (1
982) Thin solid films 68 No.1 (1980), ibid, 99 no.1.2.
3 (1983) Insoluble monolyers at liquid-gas interface
s (GLGains, Interscience Publishers, New York, 1966)
, Etc., a conventional Langmuir-Blodgett film of straight chain saturated fatty acid (hereinafter referred to as "LB film")
Has a problem in heat resistance and mechanical strength that it cannot be used as it is for practical applications.

To improve these, unsaturated fatty acids such as ω-
Tricosenoic acid, ω-heptadecenoic acid and α-octadecyl acrylic acid and unsaturated esters of fatty acids such as vinyl stearate and octadecyl acrylate, as well as polymer films of diacetylene derivatives and the like have been studied, but heat resistance is not sufficient. No, it cannot be said that it is electrically superior. Regarding polymers, polyacids, polyalcohols,
Polymers having hydrophilic groups such as ethyl acrylate and polypeptides are known to have film-forming properties.
Modified polymers have not been investigated as materials for membranes, and there is no excellent LB membrane material.

On the other hand, polyimide is used as a heat-resistant film, but it is very difficult to form a heat-resistant thin film having a pinhole of 1000 Å or more and usually 1 μm or more and 1000 Å or less without pinholes by a method such as spin coating.

The present inventors have previously proposed Japanese Patent Application No. 60-157354, 60-262122, in order to improve heat resistance and mechanical strength.
A polymer compound in which a substituent for imparting hydrophobicity is introduced into a repeating unit of the polymer compound in 60-284145 or the like (hereinafter referred to as "heat resistant polymer precursor") can be formed into a film by the LB method, and further, We proposed that the heat-resistant polymer precursor can be closed to form a heat-resistant polymer ultra-thin film.

The heat-resistant ultra-thin polymer film thus formed has good adhesion to a clean substrate due to its polar molecular structure,
Adhesion is reduced as moisture penetrates between the heat-resistant ultra-thin film and the substrate. Therefore, in order to dramatically improve the durability and reliability of an electronic device or the like using this, it is necessary for the heat-resistant polymer ultrathin film to have good adhesion to the substrate.

Means for Solving the Problems As a result of intensive studies by the present inventors, by providing a thin film of an organic compound containing an amino group or an epoxy group and an alkoxysilane group between the substrate and the heat-resistant polymer ultrathin film It was revealed that the adhesion of the heat-resistant polymer ultra-thin film to the substrate was improved.

The organic compound containing an amino group or an epoxy group and an alkoxysilane group of the present invention is obtained by ring-closing the alkoxysilane group and the heat-resistant polymer or its precursor and the precursor thereof which are easily chemically bonded to the inorganic substrate or the metal substrate. It is an organic compound that has an amino group or an epoxy group that is easily bonded (in some cases, chemically bonded) to the generated heat-resistant polymer.

By providing this organic compound layer or layer portion between the substrate and the heat-resistant polymer compound or its precursor, and further the heat-resistant polymer produced by ring-closing the precursor, the substrate and the high heat resistance can be improved. It seeks to improve the adhesion between molecules or their precursors.

DETAILED DISCUSSION The organic compound containing one or both of an amino group or an epoxy group and an alkoxysilane group used in the present invention is represented by the following general formula.

RnSiX ₃ -n n = 0,1,2 R is a monovalent group bonded to a silicon atom, and in the case of the present invention, R is selected so as to include an amino group or an epoxy group. X represents a hydrolyzable monovalent group bonded to a silicon atom, and chlorine, an alkoxy group, an acetoxy group and the like are generally used. When such an organic compound is used as an aqueous solution on a substrate, it is hydrolyzed as shown in the following reaction formula to produce silanol.

RnSiX ₃ -n + H ₂ O → RnSi (OH) ₃ -n + (3-n) HX The silanol thus produced brings about strong adhesion to the substrate. If the substrate has an oxide surface, it can react with silanol to form a covalent bond, and strong adhesion can be expected.

On the other hand, the amino group or epoxy group contained in R can react or form strong adhesion with the amphoteric polymer compound of the present invention or the heat-resistant polymer produced by ring closure of the compound. Therefore, by providing such a layer or layer portion of the organic compound between the substrate and the amphoteric polymer compound or the heat resistant polymer, the adhesiveness between the two can be improved.

Specific examples include β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (UCC trade name A-186) γ-glycidoxypropyltrimethoxysilane (also
A-187) γ-aminopropyltriethoxysilane (also A-110
0) N-β- (aminoethyl) -γ-aminopropyl-trimethoxysilane (also A-1120) γ-ureidopropyltriethoxysilane (also A-11
60) and the like, but there is no particular limitation, and commercially available silane coupling agents can be preferably used.

The above-mentioned compounds containing an amino group and an epoxy group are particularly preferable, but a silane coupling agent having another functional group in R can also be expected to have some improvement effect.

This organic compound is generally treated as an aqueous solution or the like by a means such as coating or dipping on the substrate surface, and the treatment method is not particularly limited as long as the layer or layer portion is formed. Of course, alcohol containing water may be used. The amount applied to the surface may ideally be a monomolecular layer, and the concentration of the organic compound is 5 wt% or less, preferably 1 wt% or less. After treatment, it is a preferred embodiment that excess organic compounds be removed with a suitable solvent.

Next, the heat-resistant polymer or its precursor accumulated by the LB method on the substrate coated or dipped with the organic compound or its solution and surface-treated as described above, and the LB method will be described.

The heat-resistant polymer or its precursor that can be accumulated by the LB method is described in, for example, Japanese Patent Application No. 60-157354, 60-26212.
2, 60-284145 and the like.

At least a divalent first organic group R ₁ having at least 2 carbon atoms and at least a divalent second organic group R ₂ having at least 2 carbon atoms are alternated by a divalent linking group. At least one, preferably at least one monovalent hydrogen-containing group R ₃ having 10 to 30 carbon atoms, which has a linear repeating unit that is linked and is bonded to the same repeating unit by a covalent bond, and may have a substituent. It is a polymer compound containing two.

Further, the above-mentioned heat-resistant polymer compound has introduced a substituent for imparting hydrophobicity through a covalent bond, but it has been found that a polymer compound introduced by an ionic bond can also be formed into a film by the LB method. There is. That is, the polymer compound imparted with ionic bond hydrophobicity means at least a trivalent first organic group having at least two carbon elements.
R ₁ and at least 2 having at least 2 carbon atoms
A valent second organic group R ₂ has a linear repeating unit alternately linked by a divalent linking group, and may contain a substituent bound to the same repeating unit by an ionic bond. It is a polymer compound containing at least one monovalent hydrogen-containing group R ₃ having 10 to 30 carbon atoms.

Further, it can be applied to polyimine prepared by utilizing the LB method as disclosed in JP-A-61-1108633. Practical examples of the heat-resistant polymer having a hydrophobic group introduced by covalent bonding are as follows.

In the formula, → represents isomerism.

For example, using the following equation (3), and Represents

In the present invention, when (3-1) (3-2) is alone, (3-1) (3
-2) includes the case where they coexist.

In (1) to (20), R ₃ is a hydrocarbon-containing group having 10 to 30 carbon atoms, preferably 16 to 22 carbon atoms, and an aliphatic bond, a cycloaliphatic bond to an aliphatic bond, an aromatic bond to an aliphatic bond, A monovalent group selected from those substituents is a preferred specific example, and if enumerated, Here, + m = n-5, n-10 to 30, preferably 16
To 22 and the like, and a linear aliphatic hydrocarbon group is a particularly preferred example.

Substituents for these include a halogen atom, a nitro group, an amino group, a cyano group, a methoxy group and an acetoxy group, but are not essential. However, since the fluorine atom improves the hydrophobicity over the hydrogen atom, it is desirable to use it in some cases.

That is, by containing fluorine, the length of the alkyl chain can be shortened. For example, in C ₈ F ₁₇ (CH ₂ ) k−, k = 2
Is sufficient, and it is possible to form a film having 10 carbon atoms.

The molecular weight of the heat resistant polymer compound of the present invention is not particularly limited. However, even if the molecular weight is low, film formation is possible by the film formation method of the present invention, but good heat resistance, mechanical strength, and chemical resistance cannot be obtained. On the other hand, if the molecular weight is too large, the viscosity will be too high and film formation will not be successful.

Therefore, the number average molecular weight is about 2,000 to 300,000, preferably about 10,000 to 150,000.

Further, practical practical examples of the polymer compound having a hydrophobic group introduced by ionic bond are as follows.

In the formula, → represents isomerism.

For example, if the following equation (22) is used, and Represents

In the present invention, when (22-1) (22-2) is alone, (22-1)
This includes the case where (22-2) coexists. (21) ~ (34)
At least one of R ₃ , R ₄ , and R ₄ is the same as the definition and examples of R ₃ in (1) to (20), and the other may have a substituent containing a hydrocarbon having 1 to 30 carbon atoms A group or a hydrogen atom, preferably a hydrocarbon-containing group having 1 to 4 carbon atoms or a hydrogen atom.

Next, the LB method used in the present invention will be described.

In the LB method, the substance forming the film is spread on the water surface, the substance spread on the water surface is compressed with a constant surface pressure to form a monomolecular film, and the film is transferred onto the substrate, as well as horizontally. Methods such as adhesion method and rotating cylinder method (New Experimental Chemistry Course, 18th
Rolls, interfaces and colloids, 498-508) and the like, and any commonly used method can be used without particular limitation.

The LB method is an oriented method and is a method capable of controlling the thickness in units of several tens of Å, and is an excellent method for forming a thin film of 200 Å or less, further 1000 Å or less, hundreds of Å, tens of Å,
The thin film on the substrate of the present invention also has this feature. But 10,
Membranes with a thickness of 000Å or more can also be produced by this method.

The present inventors have found and proposed that the modified polymer compound can be used alone to form a film (Japanese Patent Application No. 60-202191). However, by mixing these polymer compound and a known LB film compound, the film forming performance is improved. Is a preferred embodiment of the present invention.

The known LB film compound is a compound described in the documents cited above and known in the art. In particular, a compound of the following formula, which is composed of a hydrocarbon group having 16 to 22 carbon atoms and a hydrophilic group, is preferable.

CH ₃ (CH ₂ ) n _-1 Z CH ₂ = CH (CH ₂ ) n _-2 Z CH ₃ (CH ₂ ) C≡C−≡C (CH ₂ ) mZ where n = 16 to 22, + m = n-5, Z = OH, NH
₂ , COOH, CONH ₂ , COOR '(R' is a lower aliphatic hydrocarbon group).

In order to improve the film-forming property, the one represented by the formula of CH ₃ (CH ₂ ) n _-1 Z is superior in terms of cost, but those containing unsaturated bonds should be irradiated with light or radiation. It has a feature that can be polymerized by.

The mixing ratio of at least one compound selected from these and the polymer compound is not particularly limited.

When the components forming the film by the LB method are spread on the water surface,
In general, benzene, chloroform, etc., which do not dissolve in water and evaporate in the gas phase, are used as the solvent, but in the case of the polymer compound of the present invention, an organic polar solvent should be used together in order to increase the solubility. Is desirable. Preferred organic polar solvents are N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylformamide, N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, dimethylsulfoxide, N-methyl-2. -Pyrrolidone, pyridine, dimethyl sulfone, hexamethylphosphoramide, tetramethylene sulfone, dimethyl tetramethylene sulfone and the like.

Therefore, it is desirable to use a mixed solvent of a solvent such as benzene and chloroform and an organic polar solvent when developing the polymer compound and the known LB film compound.

When benzene, chloroform, etc. are used in combination with an organic polar solvent, it is considered that benzene, chloroform, etc. evaporate in the gas phase when the film is developed, and the organic polar solvent dissolves in a large amount of water.

The substrate used in the present invention is limited depending on what the thin film of the present invention is applied to, but is not particularly limited, and is a general inorganic substrate such as glass, alumina, and quartz. In addition to metal, Si, GaAs,
Group IV, III-V, II-VI semiconductors such as ZnS, PbTi
It is also possible to use a substrate including a ferroelectric substance such as O ₃ , BaTiO ₃ , LiNbO ₃ , and LiTaO ₃ or a magnetic thin film as a substrate.

It was also clarified that the use of the surface-treated substrate of the present invention enables stable and excellent accumulation of ultrathin films as compared with the case of using the surface-untreated substrate.

Further, after a heat-resistant polymer compound is accumulated on a surface-treated substrate by the LB method, some further form a thin film having further improved heat resistance on the substrate by partially or completely ring-closing this thin film. it can.

Among the examples of (1) to (34), these are examples that can be partially or completely closed to a 5-membered ring or 6-membered ring containing a heteroatom, and the structure after complete ring closure is as follows. Become.

The method of ring closure is not particularly limited, but in the case of imidization which is a specific example of the above formula (5), it is 200 to 4
By heating to a temperature in the vicinity of 00 ° C., the polymer compound of formula (5) And the ring closure is achieved. At this time, the group introduced for hydrophobization is eliminated as an alcohol, and the eliminated alcohol is placed under a gas flow or a vacuum if necessary at a temperature near 200 to 400 ° C. Since it can be scattered, a polyimide thin film having very good heat resistance can be obtained.

When a thin film having good heat resistance is obtained by ring closure in this way, it is desirable to select, as the known LB film compound to be mixed, from the examples given above that can be scattered under the ring closure reaction conditions.

Of course, acetic anhydride, pyridine, a chemical curing agent such as isoquinoline, which is used in general imidization, or it may be used in combination with heat.

As described above, the thin film formed on the substrate by accumulating the polymer compound of the present invention on the substrate surface-treated by the LB method and, if necessary, subsequent ring closure reaction has heat resistance, mechanical properties and chemical resistance. Also has good electrical insulation properties,
Moreover, it is a very thin film of 10,000 Å or less, 5,000 Å, 2000 Å, 10-100 if desired.
It has the characteristic that it can be 0Å.

In particular, it can be used in various devices because it can achieve good physical properties even at 1000 Å or less, several hundred Å, and 50 to 100 Å, and in particular, dielectric breakdown strength of 1 × 10 ⁶ V / cm or more. In particular, a thin film having a thickness of about 50 Å to several hundred Å is expected to have an effect of a peculiar film thickness, for example, a tunnel effect, and many interesting applications using it are possible.

Next, applications of these thin films will be described.

INDUSTRIAL APPLICABILITY The thin film of the present invention has excellent heat resistance, chemical resistance, and mechanical properties, and can be used in a wide range of fields such as the electronics field, energy conversion, and substance separation by taking advantage of the fact that it is a very thin film.

Regarding the devices in the field of electronics that take advantage of conductivity, photoconductivity, optical properties, insulation properties, thermal properties, and chemical reactivity, we first describe electrical and electronic devices.

The first important electric / electronic device including the thin film of the present invention is a device having a metal / insulating film / semiconductor structure (hereinafter referred to as MIS), which is a basic structure of a planar electronic device or an integrated circuit.

1 to 7 are typical schematic diagrams. FIG. 1 shows a semiconductor substrate on which a thin film of the present invention is formed as an insulating film and a metal electrode is provided thereon. Group IV semiconductors such as Si and Ge, GaA
III-V semiconductors such as s and GaP, CdTe, CdS, ZnS, ZnS
By using II-VI group semiconductors such as e and CdHgTe, photoelectric conversion elements such as solar cells, LEDs, and E
L, a light emitting element such as a photodiode, a light receiving element, a light detecting element, and other various sensors such as a gas sensor and a temperature sensor can be configured. Of course, the semiconductor of the present invention may be selected from single crystal, polycrystal or amorphous.

FIG. 2 is the same as FIG. 1, but such an electrode is attached when two or more devices are formed on one substrate. With such a structure, a charge transfer device such as a CCD (Charge coupled device) is manufactured, which is an interesting application.

Next, FIG. 3 shows that, in many cases, a semiconductor thin film is formed on an insulating substrate having an electrode (which may be a transparent electrode or may be patterned), and a semiconductor thin film of the present invention is formed thereon. The structure is such that a thin film electrode is provided.

FIG. 4 is different from FIG. 3 in that a thin film is provided between the insulating substrate side electrode and the semiconductor thin film. The semiconductor thin film is formed by molecular beam epitaxy (MBE) metal organic chemical vapor deposition (MOCV).
D) Atomic layer epitaxy (ALE) vapor deposition method, sputtering method,
The method is not limited and may be a method that is usually used for forming a semiconductor thin film, such as a spray pyrolysis method or a coating method.

As the semiconductor, those mentioned in FIGS. 1 and 2 can be used in the same manner, and the devices produced are also the same.

In the structure shown in FIG. 4, since a semiconductor thin film is formed on the thin film of the present invention, it is not desirable that the heat during formation exceeds the heat resistance of the thin film, but amorphous silicon etc. can sufficiently accumulate in the thin film after ring closure. Since low-temperature forming technology for other semiconductors is advancing, many semiconductors will be usable in the future.

The most important device structure of the MIS structure device is a so-called field effect transistor (FET) structure of a type in which a channel current is controlled by a gate electrode, which is represented by FIGS.

FIG. 5 uses a semiconductor substrate, whereas FIG. 6 uses a semiconductor formed on an insulating substrate, in many cases, a semiconductor thin film.

MISFET is one of the basic types of devices, which allows various devices to be made. If it is formed on a large-area substrate, a thin film transistor that drives a liquid crystal display can be constructed.

Another interesting application is the structure in which the gate electrode is removed in FIGS. 5 and 6, and by attaching an insulating film or a film sensitive to ions, gases and active substances in combination with it,
Ion-sensitive FET (ISFET) and gas-sensitive EET (Ch
em FET), immune FET (IMFET), enzyme FET
(ENFET) can be configured.

The operating principle can be explained by the electric field effect caused by the action of ions or gas active substances on the surface of the gate insulating film. However, when the thin film of the present invention is used, when it is further modified with various organic substances, conventional inorganic substances are used. It is more advantageous than In particular, in a thin film in which a long-chain alkyl group remains, the interaction between the alkyl group (hydrophobic) portion and the hydrophobic portion of the protein can be utilized.

FIG. 7 shows an example of an ISFET, which has a structure in which a semiconductor film is formed on a quartz substrate as shown, and an insulating film and an ion sensitive film are provided thereon. The thin film of the present invention can be used as this insulating film.

A preferred embodiment of the present invention is to use a compound semiconductor such as III-V or II-VI group, which is difficult to form a good insulating film by a method such as oxidation, as a semiconductor when forming a device having a MIS structure. And FE for GaAs
When forming T, Metal-Semiconduc
Although it has been put to practical use in the form of torFET (MESFET), improvement in performance is expected by adopting a MIS structure.

In addition to the effect of lowering the drive voltage when a MIS integrated circuit is constructed using GaAs, it also operates at high speed by utilizing the magnitude of carrier mobility in GaAs semiconductors (HE
MT) can be made in a very simple way.

The second important electric / electronic device including the thin film of the present invention is a device having a metal / insulating film / metal (hereinafter referred to as MIM) structure.

8 to 10 are schematic views. An insulating substrate or a semiconductor substrate is used, and a metal, an insulating film, and a metal are formed thereon in this order.

Fig. 8 shows the structure of the capacitor, which becomes a humidity sensor by tracking the change of the capacitance with humidity. Also, with this structure, a transistor having an MIM structure can be manufactured.

A thermionic transistor can be constructed as shown in FIG.

By forming a capacitor on a semiconductor or a semiconductor device as shown in FIG. 10, it can be used as a capacitor of a VLSI memory cell.

A device of the type shown in FIG. 10 in which thermoelectrons are injected into a semiconductor can also be manufactured. N instead of metal
It is also possible to make a Josephson Junction (JJ) device by using an electromotive conductor such as b.

The electric / electronic device including the third thin film is a device having an insulating film / metal structure (IM structure), and is schematically shown in FIG. It is the simplest and can be obtained by forming the thin film of the present invention as an insulating film on a metal.

One application is liquid crystal alignment films, patterned electrodes,
Usually, it is obtained by forming the thin film of the present invention on a transparent electrode such as ITO.

The next application can be used as a sensor for humidity, gas, etc. by forming the thin film of the present invention on two independent electrodes of FIGS.

Although the electric / electronic device including the thin film of the present invention has been described above, other application examples are described in particular in P.
Review of S. Vincett, GG Roberts (Thin Solid Films 68 135
~ 171 (1980).

For other semiconductor devices and compound semiconductor devices, ES Yang, Fundamentals of Semiconductor Devices
Reference may be made to the textbook of Compound Semiconductor Device [I] [II] Industrial Research Committee (1984), edited by MaGraw-Hill, 1978, edited by Imai et al.

Next, devices other than electric / electronic devices will be described.

A recording method is being adopted in which a thin film containing a dye or an inorganic thin film such as TeOx is optically read out at 0.1 by forming a bit or changing the phase. The thin film of the present invention is
A heat, especially a laser beam that is usually used for optical recording, causes a reaction to change the thickness of the thin film to form a bit, and the reaction also changes the refractive index of the thin film, so optical recording using this is possible. Is suggested.

It is clear from the above description that the thin film of the present invention is reactive to heat. However, by utilizing this reactivity, a thermally closed ring portion and a non-closed portion are formed, and the non-closed portion is formed by a solvent. It can be patterned by removing. The remaining portion has excellent heat resistance, mechanical strength, and chemical resistance, and thus can be used as a resist film. Further, as in one of the embodiments of the present invention, it is possible to make it reactive to light by using an alkyl chain having a double bond or a triple bond.

In addition, it can be applied as a clad material for a wave guide or an optical circuit component.

It is also possible to pattern by the method described for the resist to form an optical circuit. In the case of the thin film of the present invention, the refractive index can be adjusted by controlling the thickness accurately and changing the compound. This is an important requirement as an optical circuit component.

It may be suitable as a protective coating material in all fields, and the method of a mixed film or a laminated film of a functional LB material and a fatty acid generally used in the field of an LB film is used instead of the mixture of the present invention for the fatty acid. Various functionalities can be expressed by using it, and the application using this can be considered. For example, an optical conversion element or a biosensor can be made by making a film containing a dye and an enzyme.

In addition, applications in the field of substance separation using this thin film are also conceivable.

Next, the thin film and device of the present invention will be described based on Reference Examples and Examples.

Reference Example 1 2.18 g (0.01 mol) of pyromellitic dianhydride and 5.40 g (0.02 mol) of stearyl alcohol were reacted in a flask under a dry nitrogen stream at about 100 ° C. for 3 hours.

The obtained reaction product was dissolved in 40 cc of hexamethylenephosphamide and cooled to 0 to 5 ° C to obtain 2.38 g of thionyl chloride.
Was added dropwise at about 5 ° C., and after the addition, the mixture was maintained at about 5 ° C. for 1 hour to complete the reaction.

After that, 2 g (0.01 mol) of diaminodiphenyl ether dissolved in 50 cc of dimethylacetamide was added dropwise at 0 to 5 ° C., and after reacting for about 1 hour after dropping, the reaction solution was poured into 600 cc of distilled water to precipitate a reaction product. Let The precipitate was filtered or dried under reduced pressure at about 40 ° C. to obtain about 9 g of a pale yellow powder.

IR spectrum analysis and thermal analysis (T
The molecular weight was measured by GA-DTA) and GPC.

Next, the thin film and device of the present invention will be described based on Reference Examples and Examples.

Reference Example 1 2.18 g (0.01 mol) of pyromellitic dianhydride and 5.40 g (0.02 mol) of stearyl alcohol were reacted in a flask under a dry nitrogen stream at about 100 ° C. for 3 hours.

The obtained reaction product was dissolved in 40 cc of hexamethylenephosphamide and cooled to 0 to 5 ° C to obtain 2.38 g of thionyl chloride.
Was added dropwise at about 5 ° C., and after the addition, the mixture was maintained at about 5 ° C. for 1 hour to complete the reaction.

After that, 2 g (0.01 mol) of diaminodiphenyl ether dissolved in 50 cc of dimethylacetamide was added dropwise at 0 to 5 ° C., and after reacting for about 1 hour after dropping, the reaction solution was poured into 600 cc of distilled water to precipitate a reaction product. Let The precipitate was filtered or dried under reduced pressure at about 40 ° C. to obtain about 9 g of a pale yellow powder.

IR spectrum analysis and thermal analysis (T
The molecular weight was measured by GA-DTA) and GPC.

IR spectrum analysis The IR spectrum measured by the KBr disk method is shown in FIG. In the IR spectrum, characteristic absorptions of ester, amide I absorption band, II absorption band, III absorption band, alkyl chain and ether appear.

Thermal analysis (TGA-DTA) RGA-DTA (H) type manufactured by Rigaku Denki Co., Ltd., full scale TGA 10 mg, DTA 100 μV, temperature 1000 ° C., temperature increase 10 ° C./min, nitrogen gas flow (30 m / min). It is shown in FIG.

TGA has inflection points at 271, 318, 396, 592 ° C, and GTA has a characteristic peak near 657 ° C.

In addition, FIG. 16 shows the obtained precursor at 10 ° C / 400 ° C.
The results are shown when the temperature was raised at min, kept at 400 ° C. for 1 hour, returned to room temperature, and raised to 1000 ° C. at 10 ° C./min.

By maintaining the temperature at 400 ° C. for 1 hour, the weight almost reaches a constant weight and the polyimidization reaction is terminated. Even if the temperature is returned to room temperature and the temperature is raised again, the weight does not change until it exceeds 450 ° C.
It was revealed that the thermal decomposition starts at 584 ° C. which is the same as the thermal decomposition temperature of the polyimide film, and it is found that the same heat resistance as the polyimide film can be obtained by terminating the reaction of the polyimidization.

Molecular Weight Measurement by GPC The number average molecular weight produced by comparing the GPC results measured with N, N-dimethylacetamide solvent with a polystyrene standard sample was about 50,000.

Reference Example 2 10.91 g of pyromellitic dianhydride and 27.05 g of stearyl alcohol were reacted at 120 ° C. for 3 hours to give a product of 20
Recrystallization from 0m ethanol gave distearyl pyromellitate having a melting point of 133 to 137 ° C.

3.79 g of this distearyl pyromellitate was dissolved in 60 cc of hexymethylene phosphamide, cooled to 5 ° C, and 1.19 g of thionyl chloride was added dropwise at about 5 ° C, and the reaction was completed after holding for about 1 hour. Let After that, 1.2 g of diaminodiphenyl ether dissolved in 30 cc of dimethylacetamide was added dropwise at about 10 ° C., the reaction temperature was raised to about 20 ° C., the reaction was performed for 2 hours, and then poured into 400 cc of ethanol to precipitate a reaction product. . The precipitate was filtered and dried at 40 ° C. to obtain about 3.4 g of a pale yellow powder.

IR spectrum analysis, thermal analysis (TGA-DTA), GP
When the molecular weight was measured by C, the following results were obtained.

IR spectrum analysis The IR chart obtained by the KBr disk method is as shown in Fig. 17, and characteristic absorptions of ester, amide I, II, III, alkyl chain and ether are shown.

Thermal analysis (TGA-DTA) RTG-DTA (H) type manufactured by Rigaku Denki Co., Ltd. Full scale TGA 10 mg, DTA 100 μV, temperature 1000
The results of measurement at a temperature rise of 10 ° C./min in a nitrogen stream (30 m / min) are shown in FIG. 2 for TGA
Although there are inflection points at 03,270,354,403,580 ° C., DTA has no characteristic peak.

Molecular weight measurement by GPC Chloroform, N, N-dimethylacetamide (8: 2)
The number average molecular weight measured with the mixed solvent was about 15,000 in terms of polystyrene.

Example 1 The products of Reference Examples 1 and 2 were subjected to a surface pressure of 25 at 20 ° C. on redistilled water.
Treated with 1% silane coupling agent A-1100 (UCC trade name, γ-aminopropyltriethoxysilane) or A-187 (UCC trade name, γ-glycidoxypropyltrimethoxysilane) aqueous solution at dyne / cm Accumulated on a surface-treated glass substrate cured at 110 ° C.

Cumulative for Y type, cumulative ratio is 0.9-1.1 for both rising and falling
Met. The addition of stearyl alcohol molecules, which is a known LB membrane material, in an amount equal to the number of repeating units of the above product tended to accumulate in the Y-form and the cumulative ratio was better than that without stearyl alcohol.

Compared to the case of using the glass substrate without surface treatment, the state of the meniscus during accumulation and the accumulation ratio were very stable, and a good accumulated film was formed.

COMPARATIVE EXAMPLE As in Example 1, Y was generally used even when a glass substrate that had been washed by the LB method was used.
It was accumulated in the form, but it was observed that the cumulative ratio when falling was about 0.7 to 0.8.

Example 2 An example of the MIM structure will be described.

A mixture of the compound of Reference Example 2 and stearyl alcohol 1: 1 (molar ratio) was used, and under the same conditions as in Example 1, 11, 2
As a substrate for forming a cumulative film of 1, 31, 41, 51 layers, an aluminum electrode having a width of 0.5 mm is vapor-deposited on a glass substrate and treated with a silane coupling agent A-187 (0.5% aqueous solution),
The one washed with water and cured at 110 ° C. was used.

After the accumulation, it was dried for one night, treated at 400 ° C. for 1 hour under nitrogen flow, and an aluminum electrode having a width of 0.1 mm was vapor-deposited so as to be orthogonal to the aluminum electrode to prepare an MIM device as shown in FIG. A good linear relationship was obtained by measuring the capacitance at a frequency of 1 KHz at room temperature and plotting the reciprocal of the capacitance against the cumulative number of films, and complete insulation without pinholes with a dielectric breakdown strength of 1 × 10 ⁶ V / cm or more. A film was obtained.

Example 3 As a substrate, a silicon semiconductor substrate having silicon dioxide formed on its surface was treated with a 1% aqueous solution of a silane coupling agent A-1100 and cured at 110 ° C. was used. Example 2
A 51-layer cumulative film was formed in the same manner as above, and treated at 400 ° C. for 1 hour under nitrogen flow to form a polyimide thin film.

Even when this thin film was boiled at 100 ° C. for 1 hour, no peeling was observed and it was firmly adhered to the substrate. On the other hand, when A-1100 was not treated, partial peeling was observed by the same treatment.

Examples 4 to 12 By the same method as in Comparative Example 1, the compounds of the following groups A and B were allowed to act to synthesize polymer compounds. R ₃ = CH
₃ (CH ₂ ) ₁₇ The structure of the synthesized polymer compound is as follows.

Identification of these high molecular compounds was carried out by IR spectrum analysis, ¹ H
-Done by NMR etc. The results of molecular weight measurement by thermal analysis and GPC were similar to those of Reference Example 2. Especially 6
It was confirmed that the polymer compounds No. 12 to 12 form a heat-resistant ring structure by heating at 200 to 400 ° C. for ring closure reaction and elimination of stearyl alcohol (probably distearyl ether in 8).

Further, it was confirmed that the above polymer compounds could be favorably accumulated on the substrate treated with the silane coupling agent A-1100 or A-187 as in Example 1.

Example 13 2.18 g (0.01 mol) of pyromellitic dianhydride was dissolved in 50 cc of dry dimethylacetamide in 30 cc of dimethylacetamide in a flask at about 20 ° C. under a flow of dry nitrogen.
About 1.51 g (0.01 mol) of 2,5-diaminobenzamide
The mixture was added dropwise at 0 minutes and reacted for 2 hours after the addition. Dilute with dimethylacetamide and benzene (1: 1) to 1 × 10 ^-3 M
Solution was prepared, and a solution of dimethylacetamide and benzine (1: 1) prepared so that Nn-octadecyldimethylamine was 2 × 10 ⁻³ M was mixed and reacted to develop the solution for LB film. It was a liquid. When an attempt was made to accumulate this on a glass substrate treated with A-1100, a good Z type accumulation film was obtained.

Example 14 Benzidine-3,3'-dicarboxylic acid 2.72 g (0.01 mol)
Was dissolved in 50 cc of dry hexamethylphosphoramide in a flask under a flow of dry nitrogen, and terephthalic acid dicloid was dissolved in 30 cc of dry dimethylacetamide at about 20 ° C.
2.30 g (0.01 mol) was added dropwise and reacted for about 2 hours after the addition.

Dimethylacetamide was diluted with benzene (1: 1) to prepare a 1 × 10 ⁻³ M solution, and dimethylacetamide was prepared so that Nn-octadecyldimethylamine was 2 × 10 ⁻³ M. A solution of benzene (1: 1) was mixed and reacted to obtain a developing solution for LB film.

When accumulated on the A-1100-treated glass substrate in the same manner as in Example 13, a good Z type accumulated film was obtained.

EFFECTS OF THE INVENTION According to the present invention, the polymer compound modified so that a film can be formed by the LB method can be favorably accumulated on the substrate. Moreover, by partially or completely cyclizing,
By scattering the known LB film compound mixed at the same time, the heat resistance is extremely good, the chemical resistance and mechanical properties are good, and the adhesion to the substrate is improved. 10,000 Å or less, 10 if desired
Ultra thin films of up to 1000Å can be obtained.

In addition, stable and good accumulation can be achieved as compared with the case of using a substrate which is not surface-treated.

[Brief description of drawings]

1 to 7 are schematic views of a typical MIS structure device, FIGS. 8 to 10 are MIM structures, and FIGS. 11 to 13 are IM structures. 14 is an IR spectrum of the precursor obtained in Reference Example 1, FIG. 15 is a graph showing the results of thermogravimetric analysis (TGA-DTA) of the precursor obtained in Reference Example 1, and FIG. 16 is a reference example. The temperature of the precursor obtained in 1 was raised from room temperature to 400 ° C.,
Keep it there for 1 hour, let it cool down to room temperature, then 1000 ℃
It is a graph which shows the thermogravimetric analysis (TGA-DTA) result at the time of heating up. FIG. 17 is the infrared absorption spectrum of the precursor obtained in Reference Example 2, and FIG. 18 is the result of thermal analysis.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location H01L 29/28

Claims (3)

[Claims] 1. A thin film of an organic compound containing either or both of amino groups and epoxy groups and an alkoxysilane group is provided on the surface of a substrate, and a heat-resistant polymer or a precursor thereof is further provided thereon. An ultra-thin film with improved adhesion to a substrate consisting of a thin film. 2. A step of treating a substrate with an organic compound containing an aminosilane or an epoxy group or both and an alkoxysilane group, and an ultrathin film of a heat-resistant polymer or its precursor thereon is further subjected to Langmuir Brochure. A method for producing an ultra-thin film with improved adhesion to a substrate, characterized by comprising the steps of accumulating by a jet method. 3. The ultrathin film of the heat-resistant polymer is formed by accumulating the ultrathin film of its precursor by the Langmuir-Blodgett method and then heat-curing the ultrathin film of the precursor. The method according to item 2.