WO1990008402A1 - Fet transistor and liquid crystal display device obtained by using the same - Google Patents

Abstract

A field-effect transistor (FET element) wherein a pi-conjugated polymer film that serves as a semiconductor layer of the element is obtained by first preparing a pi-conjugated polymer precursor film by the use of a pi-conjugated polymer precursor soluble in a solvent and then converting the precursor film into the pi-conjugated film. A liquid crystal display device is obtained by using the FET elements as active drive elements. A large number of the FET elements can be fabricated simultaneously on a substrate having a large area at a low cost and stably operate, thus making it possible to greatly vary the current between the source and the drain by the gate voltage.

Description

 Specification

 Field-effect transistor and liquid crystal display device using the same

 The present invention relates to a field-effect transistor using an organic semiconductor (hereinafter abbreviated as an FET element) and a liquid crystal display device using the same as a driving element.

 Background art

Conventionally, FET devices using silicon or GaAs single crystal as a semiconductor layer have been known and have been put to practical use. In these devices, not only is the material used expensive, but also the device fabrication process is very complicated. However, the area in which devices can be incorporated is limited by the size of the wafer. For example, in the case of manufacturing an active drive element used for a large-screen liquid crystal display element, as long as the above-described wafer is used, there are significant restrictions on price, surface area, and area. There is. Due to such restrictions, at present, as a FET element used as a driving element in a liquid crystal display element, a thin film transistor using amorphous silicon is used as an FET element. In addition, thin-film transistors using amorphous silicon, which are used in practical applications, are also inexpensive and require a large number of devices as the display device area increases. It is becoming difficult to fabricate a single, uniform surface. Against this background, attempts have recently been made to fabricate FET devices using organic semiconductors. I have. Among organic semiconductors, those using mono-conjugated polymers have attracted particular attention because of their excellent processability and easy area enlargement, which are the characteristics of polymer materials (Japanese Patent Laid-Open No. Sho 62). -855222).

A π-conjugated polymer has a chemical structure skeleton consisting of conjugated double bonds and triple bonds. The valence band and conduction band formed by the overlapping of 7Γ-electron orbitals, and It is thought to have a band structure consisting of a forbidden band separating them. The forbidden band varies depending on the material, but is in the range of 1 to 4 eV for most 7Γ-conjugated polymers. For this reason, 7Γ-conjugated polymers themselves show only an insulator or a near-conductivity to it. However, the removal of electrons from the valence band (oxidation) or the injection of electrons into the conduction band (reduction) by chemical, electrochemical, or physical methods. (Hereinafter referred to as doping) is described as producing a carrier (carrier) that carries charges. As a result, the amount of doping can be controlled. Therefore, the conductivity can be arbitrarily changed over a wide range from the insulator region to the metal region. The 7Γ-conjugated polymer obtained when doping is oxidized becomes p-type, and in the case of reduction, it becomes n-type. This is similar to impurity addition in inorganic semiconductors. For this reason, various semiconductor devices using a 7Γ-conjugated polymer as a semiconductor material can be manufactured. As an F Ε element using a π-conjugated polymer as a semiconductor, polyacetylene (Journal of Applied Physics, J. Appl. Phys. 54, p. 3255, 1983). FIG. 15 is a sectional view of a conventional FET device using polyacetylene. In this figure, 1 is a glass serving as a substrate, 2 is an aluminum film serving as a gate electrode, 3 is a polysiloxane film serving as an insulating film, and 4 is a semiconductor layer. The polyacetylene film that functions as a metal film, and 5 and 6 are gold films serving as a source electrode and a drain electrode, respectively.

The operation of the FET device using this polyacetylene for the semiconductor layer will be described. When a voltage is applied between the source electrode 5 and the drain electrode 6, a current flows between the source electrode 5 and the drain electrode 6 through the polyacetylene film 4. At this time, when a voltage is applied to the gate electrode 2 which is provided on the glass substrate 1 and is separated from the polyacetylene film 4 by the insulating film 3, the electric field effect The conductivity of the acetylene film 4 can be changed, and accordingly, the current between the source and the drain can be controlled. This is because the width of the depletion layer in the polyacetylene film 4 close to the insulating film 3 changes depending on the voltage applied to the gate electrode 2, and is an effective positive carrier. This is thought to be due to a change in the cross-sectional area of the resulting channel. In this FET device, the source-drain current that can be changed by the gate voltage is extremely small. O, o

 Another example of an F-type element using a π-conjugated polymer as a semiconductor is poly (Ν-methylpyrrole) (Chemistry). Lett.) P. 863, 1986) and Polyphen (Appl. Phys. Lett.) 49, 1210, 1986). What is known is known. FIG. 16 is a cross-sectional view of an FET element having a semiconductor layer of poly (N-methylpyrrole) or polyphene. In this figure, reference numeral 3 denotes a silicon oxide film serving as an insulating film, 4 denotes a poly (N-methylpyrrole) film or a polyolefin film serving as a semiconductor layer, and 5 and Reference numeral 6 denotes a gold film serving as a source electrode and a drain electrode, 1 denotes a silicon plate serving both as a substrate and a gate electrode, and 2 denotes a silicon plate 7 in sonic contact. It is a metal for removing When poly (N-methylpyrrole) is used as the semiconductor layer, the current flowing between the source electrode 5 and the drain electrode 6 through the semiconductor layer 4 (conductivity) Since it can be controlled only slightly by the gate voltage, there is no practical value.

On the other hand, when a porphyrene is applied to the semiconductor layer, the current (conductivity) flowing between the source electrode 5 and the drain electrode 6 through the semiconductor layer 4 is applied to the gate voltage. Thus, it is possible to modulate 100 to 1000 times. In the past, however, since poly-olefins were conventionally produced by the electrolytic polymerization method, it was extremely difficult to fabricate many FET elements simultaneously and uniformly. There are many problems.

 As described above, in an FET element using polyacetylene and poly (N-methylpyrrole) for the semiconductor layer, the source and the source can be modulated by the gate voltage. Drain-to-drain current is too low. Furthermore, in the case of an FET device using a porophene as a semiconductor layer, the source-drain current that can be modulated by the gate voltage is large, and the stability is further improved. However, since the FET element is manufactured by means of manufacturing a polyolefin film directly on the element substrate by the electrolytic polymerization method, the number of elements in the element manufacturing process is large. It was difficult to fabricate the same FET element simultaneously on a large-area substrate at the same time, which was a problem in manufacturing.

 Disclosure of the invention

 The FET element according to the present invention comprises a 7Γ-conjugated polymer film, which acts as a semiconductor layer, and a 7 溶 剤 -conjugated polymer precursor that is first soluble in a solvent; A body film is manufactured, and then, the precursor polymer film is manufactured by changing it to a monoconjugated polymer film.

 Further, the liquid crystal display device according to the present invention uses the above-mentioned FET element as an active drive element.

In the present invention, instead of directly forming a 7Γ-conjugated polymer film as in a method such as electrolytic polymerization, a 7 可 -conjugated polymer precursor from a solvent-soluble 7Γ-conjugated polymer precursor is used. After preparing a film, this precursor polymer film was converted to a 71-conjugated polymer film. By using this ττ-conjugated polymer film as a semiconductor layer, the device fabrication process becomes remarkable and easy, and many FET devices can be simultaneously formed on a large-area substrate. Just before it can be made at a price, all the fabricated F Ε Τ elements operate stably, and the gate-to-source current increases the source-to-drain current. Ο to be able to modulate

 In addition, by using the F-type element fabricated as described above as a driving element of a liquid crystal display device, a large-area, easy-to-use, inexpensive liquid crystal having excellent performance can be obtained. A display device can now be obtained.

 The F element according to another aspect of the present invention functions as a semiconductor layer.

First, a Langmuir-Blodgett (hereinafter abbreviated as LB) film of a π-conjugated polymer precursor is prepared using a 7Γ-conjugated polymer precursor that is soluble in a solvent. The LB film is made by changing the precursor polymer LB film to a 7 共 役 -conjugated polymer LB film (this LB film is an organic thin film, but is broadly called an LB film). That is how it was done.

 Further, a liquid crystal display device according to another invention uses the above-mentioned FET element as an active drive element.

These other inventions also have the same effect as the above invention, significantly simplifying the device fabrication process, and simultaneously fabricating many FET devices on a large-area substrate at low cost. With As soon as possible, all fabricated FET elements operate stably, and the gate-to-source current can be greatly modulated by the gate voltage. It became so.

 In addition, by using the FET element manufactured as described above as a driving element of a liquid crystal display device, a large-area can be easily achieved and a low-cost liquid crystal display device having excellent performance. You can now get

 Further, in a FET element according to another invention, a region sandwiched between a source electrode and a drain electrode is formed of a 7Γ-conjugated polymer obtained from a solvent-soluble precursor. In the reaction for obtaining a 7Γ-conjugated polymer from the solvent-soluble precursor described above, a 7 共 役 -conjugated polymer is obtained by forming a laminated film of an acid-donating film for donating an acid. The molecular precursor film can be efficiently converted into a r-conjugated polymer film, and the source-drain current can be more greatly modulated by the gate voltage. 7 7 0

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a cross-sectional view showing an embodiment of an FET device according to the present invention, FIG. 2 is a cross-sectional view showing a portion corresponding to one pixel of an embodiment of a liquid crystal display device according to the present invention, and FIG. 3 and 4 are cross-sectional views each showing another embodiment of the FET device according to the present invention, and FIG. 5 is a portion corresponding to one pixel in another embodiment of the liquid crystal display device according to the present invention. FIG. 6 is a cross-sectional view showing source / drain at each gate voltage of the FET element according to the first embodiment. Figure 7, Figure 8, Figure 9, and Figure 9 show the characteristics of the current between the source and the source-drain voltage, respectively, in Example 2, Example 3, and Example 4. Fig. 10 shows the relationship between the source and drain of each of the FET elements of Example 1 and Example 4 and the FET element of the comparative example when a 50 V source-drain voltage is applied. Fig. 11 shows the same characteristics of each of the FET elements in Examples 2 and 3 and the comparative example, and Fig. 12 shows the FET in the liquid crystal display device of Example 5. Source-to-drain current vs. source-drain voltage characteristics at each gate voltage of the device. Figures 13 and 14 show the characteristics of Example 6, FIG. 15 is a cross-sectional view showing an FET device using conventional polyacetylene as a semiconductor layer, and FIG. 16 is a cross-sectional view showing a conventional poly (N-type) device. Le bi π Lumpur) or port Li Chiofu E down is a sectional view showing an FET device using as a semiconductor layer.

 In the drawings, the same reference numerals indicate the same or corresponding parts.

BEST MODE FOR CARRYING OUT THE INVENTION

 FIG. 1 is a configuration diagram showing an example of the FET element according to the present invention. In the figure, 1 is a substrate, 2 is a gate electrode provided on the substrate 1, 3 is an insulating film, 4 is a 7Γ-conjugated polymer film or its LB film that functions as a semiconductor layer, and 5 and 6 Are the source and drain electrodes, respectively.

FIG. 2 is a sectional view showing an example of the liquid crystal display device according to the present invention. In this figure, 1 is the substrate and 2 is the base. Gate electrode provided on one side of plate 1, 3 is an insulating film provided on substrate 1 and gate electrode 2, 5 is a source electrode provided on insulating film 3, and 6 is the same. The drain electrode 4 is provided on the insulating film 3 separately from the source electrode 5, and the drain electrode 4 is provided on the insulating film 3, the source electrode 5, and the drain electrode 6. 7Γ — A conjugated polymer or a semiconductor layer consisting of its LB film strength, which is in contact with the drain electrode 6 and the drain electrode 6, respectively. These 2 to 6 are FETs in the liquid crystal display device. It is part 11 of the element. Further, 7 is an electrode connected to the drain electrode 6 of the FET element 11, 8 is a liquid crystal layer, 9 is a transparent electrode, and 10 is a glass plate with a polarizing plate. The electrodes 7 and 9 are subjected to an orientation treatment. 7 to 10 are liquid crystal display portions 12 of the liquid crystal display device.

 Here, the materials used for the FET element and the liquid crystal display device according to the present invention include the following.

 The substrate 1 can be made of any insulating material. Specifically, the substrate 1 can be made of glass, aluminum sintered body, polyimide, or polyester. Inolem, Polyethylene film, Polyethylene film, Polyno. Various insulating plastics such as laxylene film can be used. In the case of a liquid crystal display device, it is preferable that the substrate 1 is transparent.

The gate electrode 2, the source electrode 5 and the drain electrode 6 are gold, platinum, chromium, and gold. Radium, aluminum, Metals such as indium and molybdenum, low-resistance polysilicon, low-resistance amorphous silicon, tin oxide, indium oxide, indium, and tin oxide It is common to use (ITO) or the like, but of course, it is not limited to these materials, and two or more of these materials can be used. Methods for providing these electrodes here include methods such as vapor deposition, sputtering, plating, and various types of CVD growth. Furthermore, a conductive organic low-molecular compound or 7: -conjugated polymer may be used. In that case, the LB method can be applied.

 In a liquid crystal display device using the FET element shown in FIG. 1 or the FET element shown in FIG. 2 as a driving portion, a p-type silicon and an n-type silicon are connected to the gate electrode 2 and the substrate I. It may be used as a function. In this case, the substrate 1 can be omitted. In this case, the volume resistivity of the p-type silicon or the n-type silicon may be any value. However, in practice, the 7Γ-conjugated polymer film 4 used as a semiconductor layer may be used. It is preferable to be smaller. Further, depending on the purpose of use of the FET element, a conductive plate or film such as a stainless steel plate or a copper plate can be used as the gate electrode 2 and the substrate 1.

Also as an insulating film 3 as long as also the insulating inorganic state, and are also available in any material of an organic, generally the acid oak Li co down (S i 0 _2), nitrided Li Con, aluminum oxide, Polyethylene, Polyester, Polyimide, Polyphenylene Sulfide, Polyparaxylene, Polyacrylonitrile, Various Insulation A LB film or the like is used. Of course, two or more of these materials may be used in combination. There is no particular limitation on the method for producing these insulating films, and examples thereof include a CVD method, a plasma CVD method, a plasma polymerization method, a vapor deposition method, a spin-coating method, and a datetime method. , A cluster ion beam evaporation method, an LB method, etc., all of which can be used. When p-type silicon or n-type silicon is used for both the gate electrode 2 and the substrate 1, the insulating film 3 may be formed by a method such as thermal oxidation of silicon. The silicon oxide film thus obtained is preferably used.

In the liquid crystal display device, the electrode 7 short-circuited with the drain electrode 6 of the FET element in the liquid crystal display section 12 has sufficient electric conductivity and is insoluble in the liquid crystal. Metal, such as gold, gold, white gold, chromium, and aluminum, and transparent electrodes such as tin oxide, indium oxide, indium tin oxide (IT IT), etc. Alternatively, an organic polymer having conductivity may be used. Of course, two or more of these materials may be used in combination. As the electrode 9 on the glass plate 10, a transparent electrode such as tin oxide, indium oxide / tin oxide (IΤ0) is generally used. Alternatively, a conductive organic polymer having appropriate transparency may be used. Alternatively, two or more of these materials may be used in combination. However, these The electrodes 7 and 9 need to be subjected to an orientation treatment such as oblique deposition or rubbing of Si ₂ . The liquid crystal layer 8 includes a guest-host type liquid crystal, a TN type liquid crystal, or a smectic.

A liquid crystal such as a C-phase liquid crystal can be used. However, when a glass is used for the substrate 1 and a transparent electrode is used for the electrode 7, the contrast can be improved by attaching a polarizing plate to the substrate 1. The ratio increases. Glass plate with polarizing plate 10 Any polarizing plate is acceptable as long as it is polarized o

 In addition, as the material of the 7 く -conjugated polymer film or its LB film 4 acting as a semiconductor layer, it can be used as long as the precursor of the 7Γ-conjugated polymer is soluble in a solvent. However, two or more kinds may be used in combination. For the preparation of a precursor LB film, a material having amphipathic properties is preferably used. 7 _ Among the compounds whose precursors are soluble in the solvent, especially the general formula (1)

(Where R and R ₂ are —H, an alkyl group or an alkoxy group, and n is an integer of 10 or more). I have. Furthermore, a 7Γ-conjugated polymer in which R, and R 2 are ら れ る is preferably used because of easy synthesis of a _π- conjugated polymer precursor. Here, the solvent refers to various organic solvents, water, and mixtures thereof. What was said.

 In particular, an organic solvent which has a lower specific gravity than water, is less soluble in water, and easily evaporates is preferably used for the preparation of a precursor LB film.

Next, a precursor of a 7Γ-conjugated polymer in which R and R ₂ are both 1 H in the general formula (1) will be described. In the general formula (1), the precursor of the 7Γ-conjugated polymer in which R and R ₂ are both 1 H is represented by the general formula (2)

(Wherein R ₃ is a hydrocarbon group having 1 to 10 carbon atoms) is preferably used from the viewpoint of storage stability. Here, any of R ₃ in the general formula (2) can be used as long as it is a hydrocarbon group having 1 to 10 carbon atoms. For example, methyl, ethyl, propyl, Isopropyl, n-butynole, 2-ethylhexyl, and cyclopihexyl groups are examples, but hydrocarbon groups having 1 to 6 carbon atoms, particularly methyl and ethyl groups, are practical. Preferred. The method for synthesizing the polymer precursor used in the present invention is not particularly limited, but a polymer precursor obtained by a sulfonium salt decomposition method described below is preferred from the viewpoint of stability. .

When the general formula (2) is obtained by a sulfonium salt decomposition method For the monomer, the general formula (3)

R ₄

S ⁺ -CH ₂ CH-S + 2 A-one (3)

R s'

(However, R ₄ and R ₅ are a hydrocarbon group having from 10 to 10 carbon atoms, and A-is a 2,5-dialkylalkylsulfonium salt represented by ^ "ion). Here, as R 4 and R ₅ in the general formula (3), any one can be used as long as it is a hydrocarbon group having 1 to 10 carbon atoms, for example, methyl and ethyl. , Prol, iso-propyl, n-butyl, 2-ethylhexyl, cyclohexyl, benzyl, etc., and a hydrocarbon group having 1 to 6 carbon atoms, especially methyl and ethyl groups. The ion A is not particularly limited, and examples thereof include halogen, a hydroxyl group, boron tetrafluoride, perchloric acid, carboxylic acid, and sulfonate ion. Among them, halogens such as chlorine and bromine and hydroxyl ions are preferable.

Water, alcohol alone, or a mixed solvent containing water and / or alcohol may be used as a solvent for obtaining general formula (2) by polymerization of）. Can be In the case of performing condensation polymerization, the reaction solution is preferably an alkaline solution, and the alkaline solution is preferably a strong basic solution having a pH of 11 or more. New Alkali that can be used is sodium hydroxide, hydroxide hydration, calcium hydroxide, quaternary ammonium salt hydroxide, sulfonium. Salt hydroxide, strong basic ion exchange resin (OH type), etc., especially sodium hydroxide, potassium hydroxide, quaternary ammonium salt hydroxide , Strongly basic ion exchange resin is preferred.

 Sulfonium salts are unstable under heat, light, especially ultraviolet light, and strong basic conditions. After condensation polymerization, sulfonium chloride is gradually removed, and the sulfonium salt is converted to the alkoxy group. It is desirable to carry out the condensation polymerization reaction at a relatively low temperature, that is, at a temperature of not more than ° C, particularly not more than 5 ° C, and more preferably not more than -10 ° C, since the conversion of the compound cannot be effectively performed. The reaction time may be appropriately determined depending on the polymerization temperature and is not particularly limited, but is usually in the range of 10 minutes to 50 hours.

According to the sulfonium salt decomposition method, after polymerization, the precursor of the 7Γ-conjugated polymer is initially a sulfonium salt, that is, a high molecular weight having one S ⁺ (A—) in the side chain.

 s R 5

Polyelectrolyte but that generates as a (polymer Suruhoniu厶塩) sulfonyl © unsalted side chains react with A Turkey Lumpur in the solution (R ₃ 0 H), alcohol in A Le The oxy group [corresponding to 0 R 3 in the formula (2)] is a side chain. Therefore, it is necessary that the solvent used contains the alcohol of R ₃ 〇H described above. These alcohols may be used alone or in combination with other solvents. good. The solvent used for mixing is not particularly limited as long as it is soluble in alcohol, but water is preferred for practical use. As for the mixing ratio when the mixed solvent is used, it is sufficient that alcohol is present, but it is preferable that the alcohol be 5 weight percent or more.

 In the reaction in which the sulfonium side chain is replaced with an alkoxy group, the sulfonium side chain can be effectively converted to an alkoxy group by raising the condensation polymerization temperature in a solvent containing alcohol after the condensation polymerization. Can be replaced by When the solvent for the polymerization contains the above-mentioned alcohol, the substitution reaction of the alkoxy group can be performed following the polymerization. On the other hand, when the solvent for the polymerization is water or the like and does not contain alcohol, the same procedure can be performed by mixing the alcohol after polymerization. In the substitution reaction with an alkoxy group, 0 to 50 ° C is preferable from the viewpoint of the reaction rate, and 0 to 25 ° C is more preferable. Since the polymer having an alkoxy group in the side chain is insoluble in a commonly used mixed solvent, it precipitates as the reaction proceeds. Therefore, it is effective to carry out the reaction time until precipitation is sufficiently generated. The reaction time is preferably 15 minutes or more, but from the viewpoint of yield, it is preferably 1 hour or more. In this way, the -conjugated polymer precursor having an alkoxy group in the side chain is separated by filtering the precipitated product.

In order to obtain a 7Γ-conjugated polymer precursor having high coatability, it is preferable that the molecular weight is sufficiently large, and at least the repetition of the 7Γ-conjugated polymer precursor of the general formula (2) is preferable. Having a unit n of 10 or more, preferably 20 to 500,000, such as a fraction A material having a molecular weight that cannot be dialyzed by dialysis treatment with a dialysis membrane having a molecular weight of 3500 or more is effectively used.

 Has a leaving group side chain such as an alkoxy group represented by the general formula (2); the r-conjugated polymer precursor has excellent solubility and is soluble in many organic solvents. Examples of these organic solvents include dimethylformamide, dimethylacetamide, dimethylsulfoxyd, dioxane, black mouth holm, and tetrahydrofura. And the like.

 For the preparation of the precursor LB film, an organic solvent which has a lower specific gravity than water, is hardly soluble in water, and easily evaporates is preferred.

 As a method for obtaining a 7Γ-conjugated polymer precursor thin film used in the present invention, a spin coat using a 7Γ-conjugated polymer precursor solution dissolved in a solvent is used. Method, cast method, dating method, c-coat method, α-report method, etc. are used. Thereafter, the solvent is evaporated to obtain a 7Γ-conjugated polymer precursor thin film, and the 7Γ-conjugated polymer precursor thin film is heated to act as a semiconductor by heating the 7Γ-conjugated polymer precursor thin film. Obtain a polymer membrane. By heating the 7Γ-conjugated polymer precursor thin film, the heating conditions for forming the 7Γ-conjugated polymer film are not particularly limited, but are practical. In the following, it is desirable to carry out the reaction under an inert gas atmosphere. Of course,

Even when the heating is performed at a temperature of 200 or less, it is possible to convert the 7-conjugated polymer precursor thin film into a monoconjugated polymer film. In addition, inert gas containing protonic acids such as HC1 and HBr When heated in an atmosphere, the conversion from a Γ-conjugated polymer precursor thin film to a 7Γ-conjugated polymer thin film often proceeds smoothly.

On the other hand, as a method for obtaining an LB film of a 7Γ-conjugated polymer precursor used in the present invention, a pure or salt aqueous solution or the like is converted into a subphase and dissolved in a solvent—a conjugated polymer. Using the precursor solution as a developing solution, a vertical immersion method using a Kuhn-type trough, a horizontal deposition method, and an LB film production method using a mu- ing-wall type trough are used. Deposit on the substrate using the LB method. After that, water is evaporated to obtain a dried 7Γ-conjugated polymer precursor LB film, and the 7Γ-conjugated polymer precursor LB film is heated to act as a semiconductor. -Obtain LB film of conjugated polymer. By heating the LB film of a monoconjugated polymer precursor, there is no particular limitation on the heating conditions for forming a 7Γ-conjugated polymer LE film, but practically 200 ^e C above, below 300 ° C, arbitrary and desired this carried out in an inert gas atmosphere. Of course, it is possible to convert the 7Γ-conjugated polymer precursor LB film into a 7Γ-conjugated polymer LB film even with heating of 200 て or less. When heated in an atmosphere of an inert gas containing protonic acids such as HC1 and HBr, the LB film of 7 共 役 -conjugated polymer is converted to the LB film of 7Γ-conjugated polymer. Conversion often proceeds smoothly.

In addition, before preparing the precursor LB film, before the 7Γ-conjugated polymer If the precursor is solvent-soluble but does not have sufficient amphipathic properties, it may be combined with a good amphipathic compound such as stearic acid arachidic acid. It is possible to produce an LB film using the developing solution prepared by mixing. In addition, it is possible to prepare an LB film by adsorbing the above-mentioned 7-conjugated high molecular weight precursor to a monomolecular film of an amphipathic compound on a subphase.

 In this way, instead of forming a 7Γ-conjugated polymer film directly into a π-conjugated polymer film or its L film as in conventional electrolytic polymerization, a solvent is first used. By preparing a polymer precursor film or its LB film using a soluble 7Γ-conjugated polymer precursor and converting it to a 7Γ-conjugated polymer film or its L-film, 7 、 -It is easy to uniformly produce a conjugated polymer film or its LB film on a large area substrate.

7: —Conjugated polymers have low electrical conductivity even after doping, but generally exhibit properties as semiconductors. However, doping processing is often performed in order to improve the characteristics of the FΕ element. The doping method includes a chemical method and a physical method. (Industrial Materials, Vol. 34, No. 4, p. 55, 1986). For the former, there are methods such as (1) doping from the gas phase, (2) doping from the liquid phase, (3) electrochemical doping, and (4) light-start doping. In the latter, there is an ion injection method, and any of them can be used. Next, FIGS. 3 and 4 are cross-sectional views showing another embodiment of the FET device according to the present invention. In FIG. 3, 13 is laminated on the 7-conjugated polymer film 4 in FIG. In FIG. 4, the acid donor film is used to promote the conversion reaction from the precursor film of the 7 共 役 -conjugated polymer 4 to the π-conjugated polymer film, since they are laminated on the substrate 1 and the gate electrode 2 respectively. It is. In FIG. 3, the positions of the 7Γ-conjugated polymer film 4 and the acid donor film 13 are exchanged, that is, the acid donor film 13 is placed on the insulating film 3, the source electrode 5 and the drain electrode 6. Even if the 7 FET-conjugated polymer film is laminated on the acid donor film 13, the fabricated FET device controls the source-drain current by applying the gate voltage. You can do it.

 FIG. 5 is a cross-sectional view showing another embodiment of the liquid crystal display device according to the present invention, in which 13 is laminated on a 7Γ-conjugated polymer film 4 and is a precursor film of π-conjugated polymer 4. It is an acid donor film that promotes the conversion reaction to π-conjugated polymers.

 The other parts in FIGS. 3, 4 and 5 are the same as the corresponding parts in FIGS. 1 and 2 described above, and the manufacturing method is also the same.

 The acid-donating layer 13 is not particularly limited as long as it is capable of injecting an acid for promoting a conversion reaction from a 7Γ-conjugated polymer precursor to a 7Γ-conjugated polymer 4. .

However, it is desirable that the acid donor film itself be an insulator from the viewpoint of FET device characteristics. For example, poly film, poly Estino-Finnorem, 'Polyethylene-Phizo-Resolem', 'Poly-Eno-Res-No-Film', 'Polyno-Rex-No-Film' Acid-impregnated polymer membranes using lime, etc., amic acid'amine complexes, tertiary amines, diazonium diluate salt. Diaryliodonium diluate salt Polymer membrane containing an acid generator such as sulfonium sulphate, sulphonic acid salt, etc., reaction of p-xylylene-bis (sulfonium π-genide) or a derivative thereof Thus, a film capable of easily desorbing an acid can be used. There is no particular limitation on the method for obtaining the acid donor film. Examples of the method include a CVD method, a plasma CVD method, a plasma polymerization method, an evaporation method, a class ion beam evaporation method, and an organic molecular beam epitaxy. Evening growth method, spin coating method, dating method, LB method, etc. can be used, all of which can be used

 Hereinafter, as an example, the π-conjugated polymer represented by the general formula (1) is used for the semiconductor layer, and the general formula (4)

(Where R ₆ is —H, an alkyl group or an alkoxy group, and n is an integer of 10 or more). A 7Γ-conjugated polymer represented by A description will be given of the object. The general formula (4) is

(However, R _s is one of H, an alkyl group or an alkoxy group, R ₇ and R ₈ are a hydrocarbon group having 1 to 10 carbon atoms, X − is a halogen such as Br, C 1, (n is an integer of 10 or more). The general formula (5) is water-soluble and can be easily prepared by the spin coating method, casting method, dating method, knuckle coating method, roll coating method, etc. A film can be formed. Therefore, a stack consisting of a π-conjugated polymer thin film precursor (general formula (2)) to be a semiconductor layer and a 7Γ-conjugated polymer precursor film (general formula (5)) to be an acid donor film There is no particular limitation on the method of obtaining the film, but the spin-coating method, casting method, and date-forming method using a 7Γ-active polymer precursor solution dissolved in a solvent. 7Γ-conjugated polymer precursor film (single-branch type) that becomes a semiconductor by a method such as the bar coating method and the roll coating method.

After obtaining (2)) and evaporating the solvent, it is preferable to laminate an acid-donating film (general formula (5)) by the same method as described above from the viewpoint of fabricating the F-element. Alternatively, after obtaining the above-described acid donor film (general formula (5)), a spin-coating method using a 7 し た -conjugated polymer precursor solution dissolved in a solvent is performed. The semiconductor layer is formed by a cast method, a dating method, a one-coat method, a roll-coat method, or the like. A ττ-conjugated polymer precursor film (general formula (2)) is obtained, and may be used as a laminated film. Of course, the above lamination may be repeated. Then, by heating the laminated film obtained above, the 71-conjugated high molecular film (general formula (1)) and the insulating film (general formula (4 ))) Is obtained. By heating a laminated film composed of a 7Γ-conjugated polymer precursor thin film (general formula (2)) and an acid donor film (general formula (5)), the -conjugated polymer film (general formula (5)) is heated. The heating conditions for obtaining a laminated film composed of the formula (1)) and the insulating film (general formula (4)) are not particularly limited, but are practically not less than 100 and not more than 300 and an inert gas atmosphere. It is desirable to work in an atmosphere.

 An acid donating method using a 7-conjugated precursor film (general formula (5)) as the acid donating film as described above will be described. The 7Γ-conjugated polymer precursor film (general formula (5)), which is an acid-donating layer, is converted to a monoconjugated polymer (general formula (4)) by heating.

 R τ

At this time, sulfonium () and acid (H

 R 8

 X). The released acid becomes a semiconductor layer 7:

-An acid is provided by diffusing into a conjugated polymer precursor film (general formula (2)). The insulator of the acid donor film can be used as both the acid donor film and the gate insulating film in the FET device (FIG. 4). In this case, the FET element fabrication process can be simplified.

FET element configured as above and this FET The operation mechanism of the liquid crystal display device using the element as a driving element will be described by describing the operation mechanism of the liquid crystal display device.

 Although there are still many unclear points about the operation mechanism, the depletion formed on the π-conjugated polymer film 4 or its LΒ film side at the interface between the 7Γ-conjugated polymer film or its LB film 4 and the insulating film 3 The width of the layer is controlled by the voltage applied between the gate electrode 2 and the source electrode 5, and the width of the layer is controlled by the effective carrier channel cross-sectional area. It is considered that the current flowing between the drain electrodes 6 changes. At this time, if the 7Γ-conjugated polymer film 4 or its LΒ film has only a ρ-type semiconductor with low conductivity, the gate electrode 2 is not a metal electrode. Even when a highly conductive material such as Ρ-type silicon, η-type silicon, or a conductive organic polymer is used, the 7Γ-conjugated polymer film 4 or its It is considered that a sufficiently large width depletion layer is formed in the LB film and an electric field effect appears.

In the liquid crystal display device of the present invention, the F-element section 11 and the liquid crystal display section 12 are connected in series. If the monoconjugated high molecular film 4 or its L-type film exhibits ρ-type semiconductivity, a negative voltage is applied to the transparent electrode 9 with respect to the source electrode 5 and the gate electrode 2 When a negative voltage is applied to the liquid crystal, the liquid crystal will light up 8 times. This is because, as described above, the resistance between the source and drain electrodes of the F Ε element decreases due to the application of a negative voltage to the gate electrode 2, and the voltage is applied to the liquid crystal display section 12. Take This is considered to be the reason. On the other hand, if the gate voltage is turned off while a negative voltage is applied to the transparent electrode 9 with reference to the source electrode 5, the liquid crystal 8 does not light. It is considered that this is because the resistance between the source and drain electrodes of the FET element is increased, and the voltage is not applied to the liquid crystal display unit 12. As described above, in the liquid crystal display device of the present invention, the driving of the liquid crystal display section 12 can be controlled by changing the gate voltage applied to the attached FET element.

 In FIG. 2, the gate electrode 2 is provided on the substrate 1. Conversely, a 7Γ-conjugated polymer film or LB film is provided on the substrate, and the source electrode and the LB film are provided thereon. A drain electrode may be provided separately from the source electrode, a gate electrode may be provided on the insulating film with an insulating film interposed between the source electrode and the drain electrode. good. In addition, a gate electrode is provided on a substrate, a 7 介 在 -conjugated polymer film or an LB film is provided thereon with an insulating film interposed, and a source electrode and the source electrode are further provided thereon. A drain electrode may be provided separately from the above. Alternatively, a source electrode is provided on the substrate and a drain electrode is provided separately from the source electrode, and a 7Γ-conjugated polymer film or LB film is provided thereon. Further, a gate electrode may be provided with an insulating film interposed.

In FIG. 3, the acid donor film 13 is provided on the 7-conjugated polymer film 4 serving as the semiconductor layer. Conversely, the gate electrode 2 is provided on the substrate 1 and the insulating film is provided. 3 intervening and Alternatively, a source electrode 5 and a drain electrode 6 may be provided, an acid donor film 13 may be provided thereon, and a 7-conjugated high molecular film 4 which is a semiconductor layer may be provided thereon. Alternatively, as shown in FIG. 4, a gate electrode 2 is provided on a substrate 1, an acid supply layer 13 is provided thereon, and a source electrode 5 and a drain electrode are provided thereon. 6 may be provided, and a 7 共 役 -conjugated polymer film 4 which is a semiconductor layer may be provided thereon, and the acid donor film 13 and the gate insulating film 3 may be used together. Alternatively, a gate electrode 2 is provided on a substrate 1, an acid donor layer 13 also serving as an insulating film 3 is provided thereon, and a semiconductor layer is provided thereon. 4 may be provided, on which the source electrode 5 and the drain electrode 6 may be provided.

 Alternatively, a gate electrode 2 is provided on a substrate 1, an insulating film 3 is interposed, a 7 4-conjugated polymer film 4 is provided thereon, and an acid donor film 13 is provided thereon, and furthermore, Further, a source electrode 5 and a drain electrode 6 may be provided. Alternatively, a source electrode 5 and a drain electrode 6 are provided on the substrate 1, and a 7Γ — conjugated polymer film 4 is provided thereon, and furthermore, an insulating layer serving also as the acid donor film 13 is provided. The gate electrode 2 may be provided with the film 3 interposed therebetween.

 In addition, in the examples of FIGS. 2 and 5, the FET element section 11 and the liquid crystal display section 12 are formed on the same substrate, but they may be formed on separate substrates and then connected. .

Hereinafter, the present invention will be described in detail with reference to specific examples, but the present invention is not limited thereto. Example 1

 A 3-inch n-type silicon with a resistivity of 4 to 8 Ωcm was heated in an oxygen stream and covered with a 3000 A thick silicon oxide film. Next, a 200 A thick copper film was formed on one side of the silicon oxide film by using ordinary vacuum deposition, photolithography, and etching techniques. Five pairs of 300 A-thick gold electrodes were provided on the ground. These five pairs of gold electrodes serve as source and drain electrodes in the FET element. Here, the width of the pair of gold electrodes, that is, the channel width, was 2 mm, and the distance between the two electrodes, that is, the channel length, was 6 μm. The substrate fabricated in this manner is hereinafter referred to as a FET element substrate.

 The temperature of the FET element substrate and the ambient temperature were set at about 60 ° C, and the poly (2,

 5 Using a solution of about 2 wt% dimethylformamide (DMF) of the precursor, spin-coat the precursor film by spin coating. Obtained on FET element substrate. At this time, the rotation speed of the spinner was set to 2000 rpm. The thickness of the obtained precursor film was about 800 A.

Next, the poly (2,5-diphenylvinylene) precursor The film-coated FET element substrate was heated in an infrared image furnace at 270 ° C. for about 2 hours under a nitrogen stream. As a result, the color of the precursor film changed from light yellow to brown. By the above heat treatment, the poly (2,5 phenylene vinylene) precursor film is converted into the poly (2,5 phenylene vinylene) film. In line with this, infrared

H ^υ

In the absorption spectrum, an absorption based on —C = C—appeared at 1590 cm— ¹ .

 Next, the silicon oxide film on the other surface of the FET element substrate covered with the film obtained as described above was mechanically separated from the bare silicon surface. Rhodium and indium alloys were applied to make ohmic contact.

 As described above, the silicon plate itself functions as a common gate electrode for the five FET elements, and the silicon oxide film on the silicon plate forms the five FET elements. It works as a common gate insulating film. Thus, the FET element shown in FIG. I was obtained. Here, 1 and 2 are silicon plates which are both a substrate and a gate electrode, 3 is a silicon oxide film which is an insulating film, and 4 is a poly (poly) which works as a semiconductor layer. Poly (2,5—Chenylenevinylene) films obtained from 2,5—Chenylenevinylene) precursor films, 5 and 6 are source and drain, respectively. A gold film that works as an electrode.

Example 2

The FET element substrate manufactured in Example 1 is used. Savoff By setting the temperature of AIDS (water) to about 2 CTC,

 5—Chenylenevinylene) Precursor Approximately 2 wt% dimethylformamide (DMF) solution 0.57 ^ mixed with chlorophonolem 9.5 Using this as a developing solution, a precursor LB film was obtained on the FET element substrate by a vertical dipping method using a Kuhn-type trough. At this time, the surface pressure was 20 mNZ m. The number of layers of the obtained precursor LB film was 100 layers.

 Next, the poly (2,5—divinylvinylene) precursor

The FET element substrate covered with the LB film was heated in an infrared image furnace for about 2 hours under a nitrogen stream at 210 ° C. As a result, the color of the precursor LB film changed from light yellow to brown. By the above heat treatment, the LB film of the poly (2,5—Chenylenevinylene) precursor is converted to the LB film of the Poly (2,5—Chenylenevinylene). And, with this, red

 H H

In external absorption spelling click preparative Le, the 1.590CH1- ¹ - C = C - group Dzu rather absorption appeared.

Next, the silicon oxide film on the other surface of the FET element substrate covered with the LB film obtained as described above is mechanically separated from the bare silicon surface to remove the gallium. Alloy of aluminum and aluminum The coating was applied to make an omic contact.

 As described above, the silicon 扳 itself acts as a common gate electrode of the five FET elements, and the silicon oxide film on the silicon 扳 has five FET elements. It works as a common gate insulating film. Thus, the FET element shown in FIG. 1 was obtained. Here, 1 and 2 are silicon plates which are both a substrate and a gate electrode, 3 is a silicon oxide film which is an insulating film, and 4 is a poly (poly) which works as a semiconductor layer. 2,5—Chenylene vinylene) The LB film of poly (2,5—Chenylene vinylene) obtained from the precursor LB film, and 5 and 6 are the source respectively. It is a gold film that works as a source and drain electrode.

Example 3

 Another embodiment using a heat treatment different from that of the second embodiment for obtaining the FET element having the structure shown in FIG. 1 will be described below. In the same manner as in Example 2, a poly (2,5-divinylvinylene) LB film (100 layers) was obtained on the FET element substrate by the LB method. However, in this embodiment, the gold electrode on the FET element substrate is replaced by a platinum electrode having a thickness of 300 A and a chromium having a thickness of 200 A as a base.

Next, the FET element substrate coated with the LB film of poly (2,5-divinylvinylene) precursor was placed in an infrared image furnace and contained hydrogen chloride gas for about 1.5 hours. Heat treatment was performed under a nitrogen stream at 9 CTC. As a result, the color of the precursor LB film changed from pale yellow to a purple with a metallic luster. Above Due to the heat treatment, the LB film of the poly (2.5-chlorovinylene) precursor is completely transformed into the LB film of the poly (2,5-chlorovinylene). Has changed to Accompanying this, infrared absorption

 H H

In the spectrum, an absorption based on one C = C — appears at 1590 cm — ′, and — C — の — C at 1099 cm — ¹

 The absorption, which is believed to be based on, disappeared.

 Thereafter, in the same manner as in Example 2, the silicon plate itself functions as a common gate electrode for the five FET elements, and the silicon oxide film on the silicon plate becomes By acting as a common gate insulating film for the two FET elements, an FET element having the structure shown in Fig. 1 was obtained. Here, 1 and 2 are silicon plates which are both a substrate and a gate electrode, 3 is a silicon oxide film which is an insulating film, and 4 is a poly (poly) which acts as a semiconductor layer. 2,5—Chenylene hinylene) The LB film of poly (2,5-chlorobenzene) obtained from the precursor LB film, and 5 and 6 are the LB films, respectively. O with platinum film acting as source and drain electrodes

Example 4

 The temperature and ambient temperature of the FET element substrate similar to that used in Example 1 were set to about 60, and the following chemical structure was obtained.

Approximately 2 wt <¾ of the poly (2,5—divinylvinylene) precursor When a precursor film was obtained on a FET element substrate by the spin cast method using a dimethylformamide (DMF) solution, the spinner rotation speed was 2000 rpm. And The thickness of the obtained precursor film was about 800 A. After evaporating the solvent to a certain extent, set the temperature and ambient temperature of the FET element substrate to about 60 ° C, and obtain the following chemical structure.

Poly (p-vinylenevinylene) precursor poly (p-vinylenevinylene) precursor is prepared by the spin-cast method using about 2% aqueous solution of the poly (p-vinylenevinylene) precursor. The film was obtained on a poly (2,5-diphenylvinylene) precursor. At this time, the number of revolutions of the spinner was set to 2000 revolutions per minute. The film thickness of the obtained precursor film was 700 A.

Next, it is coated with a two-layer film of a poly (2,5—divinylvinylene) precursor film and a poly (p—vinylenevinylene) precursor film. The FET device substrate was heated in an infrared image furnace under a nitrogen stream at 210 ° C for about 2 hours.As a result, the color of the film changed from pale yellow to dark brown or dark purple. I did. By the above heat treatment, the poly (2,51-vinylenevinyl) precursor film and the poly '(p- The multi-layered film consisting of the poly (enylenevinylene) precursor film is composed of a poly (2,5—Chenylenevinylene) film and a poly (p—film), respectively. It changes to a laminated film consisting of (Niren vinylene), and accordingly, in the infrared absorption spectrum, the poly (2,5—Chenylene vinyl) is added at 15 90 cm — The absorption based on C = C of ren and the absorption based on C = C of poly (p-phenylene vinylene) appeared at 970 cm-'. On the other hand, during the reaction by the heat treatment, there was no adverse effect such as corrosion due to acid on the element constituent parts other than the semiconductor layer composed of poly (2,5-chloro-vinylene).

 Next, the silicon oxide film on the other side of the FET element substrate covered with the film obtained as described above is mechanically separated from the bare silicon surface to form a gallium. An alloy of um and indium was applied to make an ohmic contact.

As described above, the silicon plate itself acts as a common gate electrode for the five FET elements, and the silicon oxide film on the silicon plate forms the five FET elements. It works as a common gate insulating film. Thus, the FET device shown in FIG. 3 was obtained. Here, 1 and 2 are silicon plates which are both a substrate and a gate electrode, 3 is a silicon oxide film which is an insulating film, and 4 is a poly (poly) which acts as a semiconductor layer. Poly (2,5—Chenylenevinylene) films obtained from 2,5—Chenylenevinylene) precursor films, 5 and 6 are source and drain, respectively. A gold film that works as an in-electrode, and 13 works as an acid donor film (p-f (P-phenylene vinylene) This is a poly (p-phenylene vinylene) film obtained from the precursor film.

Example 5

An example of a method for manufacturing a liquid crystal display device having the structure shown in FIG. 2 will be described below. Resistivity Ri 4 ~ 8 Ω on der, thickness 300 m of the n-type sheet re co down plate (25 mm x 40 Yuzuru) an oxide film of about 900 A thick thermally oxidized (S i 0 ₂ film) Was formed on both sides. On this surface, gold electrodes (underlying chrome 200 gold 300 A) to be source electrode 5, drain electrode 6 and electrode 7 in FIG. 2 were provided in the same manner as in Example 1. Was. Here, each of the source electrode 5 and the drain electrode 6 has an effective area of 2 mm × 4 mm, and is separated by a width of 3 zm. That is, when the FET element is used, the channel width is set to 2 and the channel length is set to 3 II m. The electrode 7 has an effective area of 17 × 19 mm ² . Hereinafter, this substrate is referred to as a liquid crystal display device substrate. Using a DMF solution of about 2 wt% of the poly (2,5-divinylvinylene) precursor, in the same manner as in Example 1, the above liquid was applied onto the display substrate. 2,5—Chenylenevinylene) A precursor film was obtained.

Next, the poly (2,5-divinylvinylene) precursor film other than the FET element portion of the liquid crystal display device substrate is washed with chloroform, and then cleaned. The substrate was heated at 200 ° C. for about 1 hour in a nitrogen stream containing about 1% hydrogen chloride gas using an infrared image furnace. By the above operation, FE Only the T element part was covered with a poly (2,5-divinylvinylene) film, and the FET element part 11 in Fig. 2 of the liquid crystal display was completed.

Was then facilities a liquid crystal display device substrate and This is S i 0 ₂ oblique vapor deposition alignment treatment Ni Let 's that to put the orientation of the liquid crystal on the glass plate 10 formed with IT 0 9 to face the. Then, a 10 m thick polyester film is formed between the liquid crystal display device substrate and the glass plate 10 on which the IT layer 9 is formed so as to face the liquid crystal display device. In this way, only a part was sandwiched, and the surrounding area was sealed with epoxy resin, leaving the same part. Then, a guest-host liquid crystal (trade name: ZLI 1841, manufactured by Merck) is injected from the unsealed portion, sealed with an epoxy resin, and a polarizing plate is mounted on the glass plate 10. Thus, the liquid crystal display unit 12 of the liquid crystal display device was completed.

Finally, peel off the part of S i 0 ₂ rear surface of the liquid crystal display device substrate, by applying a gas re U arm and Lee emissions di c arm of alloy here, O over Mi jitter co te Then, the lead wire was attached with silver paste to complete the liquid crystal display device.

Example 6

As a developing solution, a solution obtained by mixing a DMF solution (0.5%) of a poly (2,5—Chenylenevinylene) precursor of about 2 wt% and a cross-sectional form 9.5 was used. In the same manner as in Example 1, an LB film (100 layers) of a poly (2,5-chlorobenzene) precursor was obtained on the liquid crystal display device substrate. Next, after cleaning the LB film of the poly (2,5-chlorobenzenevinylene) precursor other than the FET element portion of the liquid crystal display device substrate using chloroform, the substrate is removed. The sample was heated at 90 ° C. for 1.5 hours in a nitrogen stream containing about 1% hydrogen chloride gas using an infrared image furnace. By the above operation, only the FET element part is covered with the poly (2,5-Chenylene vinylene) LB film, and the FET element part 11 in Fig. 2 of the liquid crystal display device is completed. I let it.

Then, the S i 0 ₂ obliquely deposited on glass plate 10 formed with a liquid crystal display device substrate therewith and IT 0 9 causes the opposite orientation of the liquid crystal subjected to the alignment treatment Ni Let 's that to put. Then, a 10 m thick polyester film is provided between the liquid crystal display device substrate and the glass plate 10 on which the ITO 9 is formed so as to face the liquid crystal display device so that the liquid crystal display portion becomes an opening. Sealing was carried out with epoxy resin, leaving only a part, and surrounding the same part. Then, a guest-host liquid crystal (trade name: ZL11841, manufactured by Merck) is injected from the unsealed portion, sealed with epoxy resin, and a polarizing plate is mounted on the glass plate 10. Thus, the liquid crystal display section 12 of the liquid crystal display device was completed.

Finally, peel off the part of the Si0 ₂ in the rear surface of the liquid crystal display device substrate, by applying a gas re U arm and Lee down Ji beam alloys in here, the O over Mi click co te click DOO Then, a lead line was attached to this with a silver paste to complete the liquid crystal display device.

Example 7 An example of a method for manufacturing a liquid crystal display device having the structure shown in FIG. 5 is described below. A DMF solution of about 2 wt% of a poly (2,5-divinylvinylene) precursor was used on the above liquid crystal display device substrate, and the poly (2,5,4-vinylene) precursor was used in the same manner as in Example 4. 5—Chenrenbiniren) A precursor film was obtained. Next, about 2 wt% of the poly (Nora-phenylenevinylene) precursor is placed on the poly (2,5-divinylvinylene) precursor film. Using a 1% aqueous solution, a poly (paraphenylenevinylene) precursor film was obtained in the same manner as in Example 4. The poly (2,5-divinylvinylene) precursor and the poly (paravinylenevinylene) precursor other than the FET element portion of this liquid crystal display device substrate After cleaning the film using a cloth hood, the substrate was washed for about 1 hour in a nitrogen stream using an infrared image furnace.

Heated at 200 ° C. By the above operation, only the FET element is covered with poly (2,5-divinyl vinylene) and poly (para-phenylenevinylene), and the liquid crystal display Of these, the FEB element section 11 in FIG. 5 was completed. Next, by the same operation as in Example 5, the liquid crystal display unit 12 of the liquid crystal display device was completed. Further, a liquid crystal display device was completed in the same manner as in Example 5.

Comparative example

The device of the comparative example was produced according to the above-mentioned document (Appl. Phys. Lett., Vol. 49, p. 1210, 1986). In other words, 75 acetonitrile nozzles have 2,2'-dithiophene as monomers. 0.15 g of benzene was dissolved, 0.55 g of tetraethylammonium perchlorate was dissolved as an electrolyte, and this was used as a reaction solution.High-purity nitrogen gas was passed through the reaction solution. After sufficient degassing, the FET element substrate obtained in Example 1 was immersed in this. Next, a constant current (100 A Zcrf) was passed between the five pairs of gold electrodes on the FET element substrate as working electrodes and a platinum electrode (10 X 20 mm) as the working electrode for 480 seconds to perform electrolytic polymerization. A polysilicon film with a thickness of about 1400 A was obtained on the paired gold electrodes and on the silicon oxide film around the gold electrodes. Since a large amount of perchloric acid ion is doped into the polyolefin film at the same time as the electrolytic polymerization, the potential of the five pairs of gold electrodes is immediately saturated after the electrolytic polymerization. The voltage was set to 0 V to perform dedoping, and the poly- finin film was given conductivity similar to that of a semiconductor. The obtained FET device was washed twice with acetonitril, and then dried in a vacuum desiccator.

 Next, the characteristics of the devices obtained by Examples 1 to 7 and Comparative Example are described.

First, FIG. 6 shows the electrical characteristics of one of the five FET elements obtained in Example 1. In Fig of this, the horizontal axis is the Soviet Union over the scan 'de Rei down between the voltage (V _{D s)} Der Ri vertical axis source over the scan-de Tray down between the current (I s) Ru Der. When the gate voltage (V _G ) is 0 V, I s hardly flows even if VD _s increases, but large I s flows when a negative V _c is applied. In addition, areas where V _{D s} is large In the figure, saturation of I s was observed, and the electrical characteristics of a typical enhancement-type field-effect transistor were obtained. As can be seen from the figure, the source-drain current can be greatly modulated by the applied gate voltage. The characteristics in Fig. 6 are the characteristics of one of the five fabricated FET elements, but when the characteristics of the remaining FET elements were measured, the characteristics were almost the same as the characteristics in Fig. 6. showed that. When these elements were left in the air for about one month, and their electrical characteristics were measured again, the characteristics were hardly changed, and the elements obtained in this example had extremely high stability. Next, the electrical characteristics of one of the five FET elements obtained in Example 2 and the five FET elements obtained in Example 3 were found to be excellent. The electrical characteristics of one of the FET elements are shown in FIGS. 7 and 8, respectively. In view of this is found, the horizontal axis Resona over scan de Tray down voltage (V _{D s)} Der, the vertical axis represents source over scan 'de Tray down between current (I _s) Ru der. When the gate voltage (V _G) Power 0 V is, I Ni I'm flows large I _s when the V _{D s} is I _s even One Do rather than size was applied殆etc. flow of Iga, a negative VG You. In the region where VD s is large, saturation of 1 _s was observed, and the electrical characteristics of a typical enhancement-type effect-type transistor were obtained. As can be seen from these figures, the source-drain current can be greatly modulated by the applied gate voltage. The characteristics shown in Figs. 7 and 8 show the characteristics of the five FET elements fabricated in each example. Although the characteristics of one of the elements were measured, the characteristics of the remaining FET elements were also measured. The characteristics were almost the same as those in Figs. 7 and 8. Further, when these elements were left in the air for about one month, and their electrical characteristics were measured again, the characteristics were hardly changed, and the elements obtained in this example had extremely excellent stability. I understood.

FIG. 9 shows the electric characteristics of one of the five FET devices manufactured in Example 4 of the FET device. In this figure, the horizontal axis represents the source-drain distance between the source and the drain (VD _s ), and the vertical axis represents the source-drain current (I s). As in Example 1, the electric characteristics of a typical enhancement-type field-effect transistor were obtained. As can be seen from the figure, the source-to-drain current can be greatly modulated by the applied gate power E as compared to FIG. 6 of the first embodiment.

FIG. 10 shows the constant source-drain voltage of one of the five FET elements manufactured in Example 1 and Example 4 and the FET element manufactured in the comparative example. It shows the source-drain current-gate voltage characteristics under the condition of 50 V). In view of this, the horizontal axis represents Ri Ah at gate conductive E (V _G), the vertical axis represents Ru source over scan de Tray down between current (I s) der. As is clear from FIG. 10, in the FET device obtained in Example 1, the source-drain current that can be modulated by the gate voltage is more than four digits. Further, in the FET device obtained in the fourth embodiment, the source / drain that can be modulated is used. In contrast to the conventional case, the gate-to-source current, which can be modulated by the gate voltage, is only two and a half digits, while the in-current reaches five digits or more. . As described above, the characteristics of the FET elements obtained in Examples 1 and 4 were greatly improved as compared with the conventional FET elements.

Next, Fig. 11 shows one of the five FET elements fabricated in Example 2, one of the five FET elements fabricated in Example 3, and a comparative example. The figure shows the source-drain current-gate voltage characteristics of the FET device under the condition of constant source-drain voltage (50 V). In view of this, the horizontal axis represents the gate voltage (V _c) der is, the vertical axis represents source over scan de Rei down between current (I s) Ru der. As can be seen from FIG. 11, the source-drain current that can be modulated by the gate voltage in the FET devices obtained in the second and third embodiments. In contrast, the conventional FET device of the comparative example has only two and a half digits of the source-drain current that can be modulated by the gate voltage, while the current reaches four digits or more. As described above, the characteristics of the FET devices obtained in Examples 2 and 3 were greatly improved as compared with the conventional FET device.

FIG. 12 shows the source-drain current-source-drain current when the gate voltage of the FET element in the liquid crystal display device obtained in Example 5 is changed. FIG. 4 is a characteristic diagram illustrating voltage characteristics. In this figure, the horizontal axis represents the source-drain voltage (VDs), and the vertical axis represents the source-drain current (Is). In the figure Therefore, when the gate voltage of the FET element is set to high, even if a voltage is applied between the source electrode and the drain electrode, almost no current flows between the tooth and the drain. However, a larger source-drain current flowed as the negative gate voltage was applied. Since the FΕ element and the liquid crystal display are connected in series, a liquid crystal is connected between the transparent electrode 9 on the glass plate 10 of the liquid crystal display and the source electrode 5 of the FΕ element. When a sufficient voltage is applied for driving and a negative voltage is applied to the gate electrode 2, a voltage is applied to the liquid crystal display, and the liquid crystal 8 is oriented and the liquid crystal is aligned.

 The display was driven, but when the gate voltage was set to 0 V, no voltage was applied to the liquid crystal display and the liquid crystal display stopped driving. That is, the driving of the liquid crystal could be controlled by the attached FET element using the 7Γ-conjugated polymer film as the semiconductor layer. In terms of stability, the liquid crystal display device of this example operated stably even after one month or more.

 FIG. 13 shows the source-drain current-source drain when the gate voltage of the F Ε element in the liquid crystal display device obtained in Example 6 was changed. FIG. 4 is a characteristic diagram showing an inter-voltage characteristic.

In view of this, the horizontal axis represents source over scan 'de Tray down voltage (V _{D s),} the vertical axis represents source over scan' shows the de lay down between current (I s). In the figure, when the gate voltage of the FET element is set to 0 V, even if voltage E is applied between the source electrode and the drain electrode, the current between the source and drain is almost zero. Source-drain current force is greater when negative gate voltage is applied flowed. Since the FET element and the liquid crystal display are connected in series, the liquid crystal 8 is driven between the transparent electrode 9 on the glass plate 10 of the liquid crystal display and the source electrode 5 of the FΕ element. When a negative voltage is applied to the gate electrode 2, a voltage is applied to the liquid crystal display, and the liquid crystal 8 is oriented and the liquid crystal display is driven. When the voltage was set to 0 V, no voltage was applied to the liquid crystal display and the driving of the liquid crystal display stopped.

That is, the liquid crystal drive could be controlled by the attached FET device using the attached 7Γ-conjugated polymer LB film as the semiconductor layer. Further, in terms of stability, the liquid crystal display device of this example operated stably even after more than one month.

 FIG. 14 shows the current between the source and the drain when the gate voltage of the F Ε element in the liquid crystal display device obtained in Example 7 was changed, and the source and drain. FIG. 4 is a characteristic diagram showing an inter-electrode voltage characteristic.

 In this figure, the horizontal axis shows the source-drain voltage (VDS), and the vertical axis shows the source-drain current (Is). As can be seen from the graph, as compared with FIG. 12 of the fifth embodiment, the current value between the source and the drain when the gate voltage was applied was increased, and the characteristics were improved. Further, similarly to Embodiment 5, the driving of the liquid crystal could be controlled by the present FET element. The stability was also the same as in Example 5.

In Examples 5 to 7, only one FET element and liquid crystal display section were manufactured to form a liquid crystal display device.However, a plurality of FET elements and liquid crystal display sections were manufactured using the same method to form a liquid crystal display. It can also be a device. However, in that case, processing such as patterning using a photo register is required.

Industrial applicability

 As described above, the present invention relates to a field-effect transistor using an organic semiconductor and a liquid crystal display device using the same, and the field-effect transistor and the driving element using the same. Applied to liquid crystal display devices.

Claims

Range of Iff request

 1. Source electrode, drain electrode, current path between source electrode and drain electrode, formed from 7 電極 -conjugated polymer obtained from solvent-soluble precursor A semiconductor layer to be formed, an insulating film opposed to the semiconductor layer, and a gate electrode provided on the opposite side of the insulating film to the semiconductor layer and controlling the conductivity of the semiconductor layer by applying a voltage. Field-effect transistor equipped with

 2. The 7Γ-conjugated polymer obtained from the solvent-soluble precursor has the general formula

 (Where R and R 2 are one of H, an alkyl group or an alkoxy group, and n is an integer of 10 or more). The field-effect transistor described in paragraph 1. 3. The current path between the source electrode, the drain electrode, and the source and drain electrodes. A dielectric film that is not obtained from the LB film of the soluble precursor and that is provided on the opposite side of the dielectric layer opposite to the semiconductor layer of the semiconductor formed of the 7-conjugated polymer LB film. A field-effect transistor provided with a gate electrode that is controlled by a voltage for applying the conductivity of the semiconductor layer.

D source electrode, drain electrode, source electrode and drain electrode It is a current path between the electrodes and is obtained from a solvent-soluble precursor. 71—A semiconductor layer formed of a conjugated polymer, in contact with this semiconductor layer, In a reaction for obtaining a 7-conjugated polymer from a body, an acid donating film for donating an acid, an insulating film facing the semiconductor layer, and an insulating film provided on a side of the insulating film opposite to the semiconductor layer; To apply the conductivity of the layer

A field-effect transistor with a gate electrode controlled by EE.

 5. The 7Γ-conjugated polymer obtained from the solvent-soluble precursor has the general formula

5. The field effect transistor according to claim 4, wherein R i and R ₂ are represented by —H, an alkyl group, or an alkoxy group, and n is an integer of 10 or more. Transistor.

6. The acid-donated membrane has the general formula

5. The method according to claim 4, wherein R ₆ is a 7Γ-conjugated polymer represented by —H, one of an alkyl group and an alkoxy group, and n is an integer of 10 or more. Field effect transistor

7. Claim 4 wherein the gate insulating film also serves as an acid donor film

Spine ¾7 ト ラ Tiger Noji, Star.

 8. Source electrode, drain electrode, current path between source electrode and drain electrode, formed from 7Γ-conjugated polymer obtained from solvent-soluble precursor A semiconductor layer to be formed, an insulating film facing the semiconductor layer, and a gate electrode provided on the opposite side of the insulating layer to the semiconductor layer and controlling the conductivity of the semiconductor layer by applying a voltage. A field effect transistor having a transistor, a driving unit comprising the same, and one of the source electrode and the drain electrode connected in series to be applied to the gate electrode A liquid crystal display device having a liquid crystal display unit that is controlled by changing a voltage.

 9. The current electrode between the source electrode and drain electrode, the source electrode and the drain electrode, and the π-electrode obtained from the solvent-soluble precursory LΒ film. A semiconductor layer formed of an L-layer film of a conjugated polymer, an insulating film opposed to the semiconductor layer, and provided on the opposite side of the insulating film from the semiconductor layer, and the conductivity of the semiconductor layer is also applied. A driving unit comprising a field-effect transistor having a gate electrode controlled by a voltage to be applied, and a series connection with one of the source electrode and the drain electrode. A liquid crystal display device having a liquid crystal display unit controlled by changing a voltage applied to the gate electrode

10. The current path between the source electrode and the drain electrode, and between the source electrode and the drain electrode, and is obtained from a solvent-soluble precursor. A semiconductor layer formed of a ττ-conjugated polymer, an acid donating film that provides an acid in a reaction in contact with this semiconductor layer and obtains a 7Γ-conjugated polymer from the solvent-soluble precursor, A field effect type including an insulating film facing the semiconductor layer, and a gate electrode provided on a side of the insulating film opposite to the semiconductor layer and controlling the conductivity of the semiconductor layer by applying a voltage; A transistor connected to a transistor, and one of the source electrode and the drain electrode connected in series to change the voltage applied to the gate electrode. A liquid crystal display device having a liquid crystal display section controlled by a liquid crystal display.