JP2007273938A - Method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic semiconductor device having high durability with low cost. <P>SOLUTION: A method of manufacturing a semiconductor device includes at least a step of providing a crystallization acceleration layer on a substrate, a step of applying an organic semiconductor precursor on the crystallization acceleration layer, and a step of simultaneously applying light energy and thermal energy to the organic semiconductor precursor to form a layer of an organic semiconductor. The thermal energy is preferably applied by heating the substrate from the outside. The crystallization acceleration layer preferably has the function of accelerating the bonding of crystal grains. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a semiconductor element using a precursor of an organic semiconductor compound.

  The development of thin film transistors using organic semiconductors has been gradually active since the late 1980s. In recent years, the basic performance of a thin film transistor using an organic semiconductor has exceeded the basic performance of a thin film transistor using amorphous silicon. The organic semiconductor material often has a high affinity with a plastic substrate on which a semiconductor element such as a thin film FET (Field Effect Transistor) is formed. Accordingly, the organic semiconductor material is attractive as a material for a semiconductor layer in an element that requires flexibility or lightness. In addition, some organic semiconductor materials can be formed using a solution coating or printing method. When such a material is used, a large-area element can be easily manufactured at low cost.

  Examples of organic semiconductor materials proposed so far include the following. First, acenes such as pentacene and tetracene disclosed in Patent Document 1, phthalocyanines including lead phthalocyanine disclosed in Patent Document 2, and low-molecular compounds such as perylene and its tetracarboxylic acid derivatives. Patent Document 3 proposes an aromatic oligomer represented by a thiophene hexamer called α-thienyl or seccithiophene, and further polymer compounds such as polythiophene, polythienylene vinylene, and poly-p-phenylene vinylene. ing. Many of these are described in Non-Patent Document 1.

  Characteristics such as nonlinear optical characteristics, conductivity, and semiconductor characteristics required when manufacturing an element using these compounds as a semiconductor layer largely depend on crystallinity and orientation as well as material purity.

  By the way, many of low molecular compounds (for example, pentacene) having an extended π-conjugated system have high crystallinity and are insoluble in a solvent. Therefore, a thin film made of these compounds is almost always formed by using a vacuum deposition method. Pentacene has been shown to exhibit high field-effect mobility, but there is a problem that it is unstable and easily oxidized in the atmosphere and easily deteriorates. In addition, when vacuum film formation such as vacuum deposition is used, the merit of the organic semiconductor material that can be manufactured at low cost is reduced.

  On the other hand, an organic semiconductor using a π-conjugated polymer can often form a thin film easily by a solution coating method or the like. Therefore, since organic semiconductor films using π-conjugated polymers are often excellent in moldability, application development has been promoted (Non-patent Document 2). In the π-conjugated polymer, it is known that the arrangement state of molecular chains has a great influence on electric conductivity. Similarly, it has been reported that the field-effect mobility of a π-conjugated polymer field-effect transistor greatly depends on the arrangement state of molecular chains in the semiconductor layer (Non-patent Document 3). However, since the molecular chains of the π-conjugated polymer are arranged between the application of the solution and the drying, the molecular chain arrangement may change greatly depending on the environment and the application method. . Therefore, the field effect mobility varies depending on the application conditions, and there is a concern that stable manufacturing is difficult.

In recent years, FETs using a film in which a thin film made of a soluble precursor of pentacene is formed by coating and converted to pentacene by heat treatment or light irradiation have been reported (Non-Patent Document 4, Patent Document 4, and Patent Document 5). ). When the precursor is converted to pentacene by heat treatment, there is a problem that high-temperature treatment is required for the conversion to pentacene, and a desorbed component having a large mass must be removed under reduced pressure. On the other hand, when the precursor is converted to pentacene by light treatment, high-temperature treatment is not necessary, but sufficient semiconductor characteristics are not obtained due to insufficient crystallization of the obtained pentacene film. It was.
JP-A-5-55568 Japanese Patent Laid-Open No. 5-190877 JP-A-8-264805 JP 2004-266157 A JP 2004-221318 A Advanced Material, 2002, No. 2, p. 99 to 117 “Japan Journal of Applied Physics”, Applied Physics Society, 1991, Vol. 30, p. 596 to 598 “Nature” Nature Publishing Group, 1999, vol. 401, p. 685 to 687 J. et al. Appl. Phys. 79, 1996 p. 2136

  As described above, conventionally, when manufacturing a semiconductor element such as a field effect transistor using an organic semiconductor compound, a semiconductor having good crystallinity and orientation is obtained through a process such as vacuum film formation. Layers have been formed. However, vacuum film formation is expensive, and acenes, which are representative examples of organic semiconductors, are subject to oxidation and easily deteriorate. Moreover, the method for forming a film having excellent orientation and crystallinity in order to obtain sufficient semiconductor characteristics has been a problem for those in which a simple method is applied by a coating method.

  The present invention has been made to solve this problem, and it is an object of the present invention to provide a field effect transistor that can form an organic semiconductor layer having high crystallinity and orientation and that exhibits high field effect mobility.

  The present invention is a method for producing a semiconductor device having an organic semiconductor layer, the step of providing a crystallization promoting layer on a substrate, the step of applying an organic semiconductor precursor on the crystallization promoting layer, and the organic And a step of forming a layer made of an organic semiconductor by simultaneously applying light energy and heat energy to the semiconductor precursor.

  The present invention is also a method for producing a semiconductor element, characterized in that the thermal energy is applied by heating the substrate from outside. Here, “heating from the outside” means that thermal energy is applied separately from the energy generated when the organic semiconductor precursor or the substrate generates heat upon receiving light energy.

The present invention is also the method of manufacturing a semiconductor element, wherein the crystallization promoting layer has a function of promoting the bonding between crystal grains.
In the present invention, the step of forming a layer made of an organic semiconductor by simultaneously applying light energy and thermal energy to the organic semiconductor precursor includes a step of causing a desorption reaction in the organic semiconductor precursor. This is a method for manufacturing a semiconductor element.

The present invention is also a method for manufacturing a semiconductor device, characterized by using a reverse Diels-Alder reaction as the elimination reaction.
In the present invention, the step of applying the organic semiconductor precursor on the crystallization promoting layer may be a step of applying or printing a solution containing the organic semiconductor precursor on the crystallization promoting layer. This is a method for manufacturing a semiconductor device.

The present invention is also a method for manufacturing a semiconductor element, characterized in that a layer containing a polysiloxane compound is provided as the crystallization promoting layer.
Moreover, this invention is a manufacturing method of the semiconductor element characterized by using the compound which has at least the structure shown by following General formula (1) as at least 1 type among the said polysiloxane compounds.

(In the formula, R ₁ to R ₄ are a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an alkenyl group, .R ₁ to R ₄ is either a substituted or unsubstituted phenyl group, or a siloxane unit Each may be the same or different, and n is an integer of 1 or more.)

  In the present specification and claims, the term “substituted or unsubstituted” means that a hydrogen atom, methyl group or methylene group in the target group or unit is replaced with another atom or group. It indicates that it may be. Here, examples of other atoms or groups include a halogen atom, a hydroxyl group, a cyano group, a phenyl group, a nitro group, a mercapto group, and a glycidyl group. When a methyl group or a methylene group is substituted, the number of carbon atoms means the number of carbon atoms after substitution (that is, actual).

  Moreover, this invention is a manufacturing method of the semiconductor element characterized by using the polysiloxane compound which has a structure shown by the following general formula (2) or the following general formula (3) as at least 1 type among the said polysiloxane compounds. is there.

(Wherein R _{5 to} R ₈ are any of a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an alkenyl group, and a substituted or unsubstituted phenyl group. Each of R _{5 to} R ₈ is (M and n are integers of 0 or more, and the sum of m and n is an integer of 1 or more.)

(Wherein R _{9 to} R ₁₂ are each a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an alkenyl group, or a substituted or unsubstituted phenyl group. Each of R _{9 to} R ₁₂ May be the same or different, r and p are integers of 0 or more, and the sum of r and p is an integer of 1 or more.)

  Note that “or” is a concept including “and”. Therefore, the case where at least one of the polysiloxane compounds has both the structure represented by the general formula (2) and the structure represented by the general formula (3) is also included in the present invention. Of course.

  Further, the present invention is characterized in that the organic semiconductor precursor has at least one selected from the bicyclo structure represented by the following general formulas (4) and (5) as a partial structure in the molecule. A method for manufacturing a semiconductor device.

(In the formula, R ₁₃ and R ₁₄ each independently represents an oxygen atom, a sulfur atom, or NR ₁₅ , where R ₁₅ is a linear or branched alkyl group having 1 to 12 carbon atoms, an alkenyl group. , An alkoxy group, an alkylthio group, an alkyl ester group, an aryl group, and a hydroxyl group.

(In the formula, R ₁₆ represents an oxygen atom or a sulfur atom.)
Moreover, this invention is a manufacturing method of the semiconductor element characterized by using the compound shown by following General formula (6) as said organic-semiconductor precursor.

(In the formula, the A ring represents any of the bicyclo rings represented by the general formula (4) or (5). R ₁₇ and R ₁₈ represent a hydrogen atom, an alkyl group, an alkoxy group, an ester group, or a phenyl group. R ₁₉ to R _{26 each} represents a hydrogen atom, alkyl group, alkoxy group, aryl group, heterocyclic group, aralkyl group, phenoxy group, cyano group, nitro group, ester group, carboxyl group or halogen atom R ₁₇ , R ₁₈ R ₁₉ to R ₂₆ may be the same as or different from each other, and R ₂₀ and R ₂₁ , R ₂₄ and R ₂₅ are connected to each other to form an A ring or a 5- or 6-membered heterocyclic ring. T, u, and v are integers greater than or equal to 0. The sum of t to v is an integer greater than or equal to 1.)

According to the present invention, there is provided a semiconductor device comprising the compound represented by the general formula (6), wherein the A ring is represented by the general formula (4), and R ₁₃ and R ₁₄ are oxygen atoms. Is the method.

  The present invention also provides a method for producing a field effect transistor having an organic semiconductor layer, a step of providing a layer containing a polysiloxane compound on a substrate, and an organic semiconductor precursor on the layer containing the polysiloxane compound. A method for manufacturing a semiconductor device, comprising: a step of applying a body; and a step of simultaneously applying light energy and heat energy to the organic semiconductor precursor to form a layer made of an organic semiconductor. Such a manufacturing method can be combined with the invention described so far by replacing “crystallization promoting layer” with “layer containing a polysiloxane compound”.

In addition, the present invention is a method for manufacturing a semiconductor element, wherein a field effect transistor is manufactured as the semiconductor element.
It is within the scope of the present invention to appropriately combine the above features.

According to the present invention, a semiconductor element having excellent orientation and crystallinity can be obtained.
Further, according to the present invention, a semiconductor element can be obtained by a simple method.

Hereinafter, the present invention will be described in detail.
The inventors of the present invention formed a high-quality organic semiconductor layer by applying an organic semiconductor precursor on a layer containing a polysiloxane compound and then simultaneously applying light energy and thermal energy to the organic semiconductor precursor. Found to be effective to do. Hereinafter, a layer containing a polysiloxane compound may be simply referred to as a “polysiloxane compound layer”. In the method of forming an organic semiconductor layer, after forming a thin film by laminating an organic semiconductor precursor and a layer that promotes crystallization (crystallization promoting layer) or a layer containing a polysiloxane compound, light energy and thermal energy are simultaneously applied. give. According to such a method, an organic semiconductor crystal that is continuously uniform and has few defects at the interface can be formed on the entire substrate, and an organic semiconductor element that exhibits high field-effect mobility can be manufactured. Conceivable. Such a method is considered to be particularly effective for producing an organic field effect transistor which is an example of an organic semiconductor element.

  Within the scope of the study by the present inventors, the polysiloxane compound is considered to have an action of promoting crystallization of an organic semiconductor. Therefore, the present invention is considered to be appropriate when not only a polysiloxane compound but also a layer that broadly promotes crystallization of an organic semiconductor (crystallization promoting layer) is used. Here, according to observations and considerations by the present inventors, the crystallization promoting layer has a crystallization promoting function as described below. That is, the crystallization promoting function refers to a function that promotes the stabilization of grain formation (sometimes accompanied by movement or rotation) and / or the joining of crystal grains. Therefore, the crystallization promoting layer is a layer that promotes the stabilization of crystal grains (sometimes accompanied by movement or rotation) and / or the bonding between crystal grains.

  In the present invention, the underlying structure on which the crystallization promoting layer is formed (in the case of a field effect transistor, generally a structure comprising a base material, a gate electrode, and a gate insulating layer. However, the gate insulating layer May be omitted, or depending on the stacking order, it may be a base material alone, or other layers may be formed).

The crystallization promoting layer of the present invention is preferably made of a polysiloxane compound.
Regardless of whether it is a crystallization promoting layer, the polysiloxane compound used in the present invention is a polymer having a siloxane structure (—Si—O—) and an organosilane structure. That is, as long as it has these structures, the polysiloxane compound may be a copolymer with another organic polymer or inorganic polymer. In the case of a copolymer with another polymer, a siloxane structure or an organic silane structure may be present in the main chain, or may be present in the side chain by graft polymerization or the like. The organosilane structure is a structure in which Si and C are directly bonded.

  As the polysiloxane compound used in the present invention, those having various structures such as a straight chain and a ring can be considered. The polysiloxane compound of the present invention more preferably has a high-order crosslinked or branched structure. The higher-order bridged or branched structure described here includes a net-like, ladder-like, cage-like, star-like, and dendritic structure. In addition, a crosslinked or branched structure does not necessarily have to be formed via a siloxane structure. A structure in which organic groups such as a vinyl group, an acryloyl group, an epoxy group, and a cinnamoyl group are cross-linked with each other or a structure branched through a trifunctional or higher functional organic group may be included.

The polysiloxane compound used in the present invention has, for example, a structure represented by the following general formula (1). In such a structure, the main chain is a siloxane unit, and the side chain (R _{1 to} R ₄ ) is a substituent having an organic group such as a hydrogen atom or a carbon atom.

In the formula, R _{1 to} R ₄ are any of a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted phenyl group, or a siloxane unit. Each of R _{1 to} R ₄ may be the same or different.

Examples of the substituted alkyl group include an alkyl group in which a hydrogen atom is substituted with a halogen atom, a hydroxyl group, a cyano group, a phenyl group, a nitro group, a mercapto group, or a glycidyl group. Further, a methyl group or a methylene group may be substituted with an amino group or the like. Furthermore, examples of the substituted phenyl group include a phenyl group in which a hydrogen atom is substituted with a halogen atom, a hydroxyl group, a cyano group, a nitro group, a mercapto group, or a glycidyl group. Of course, a substituent is not restricted to these. These examples are applicable to all of R and R _n (n is a natural number) in the siloxane compound described below, except in exceptional cases where it is not logically possible.

The substituents R _{1 to} R ₄ may be siloxane units as shown below.

(In the formula, R is either a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted phenyl group, or a siloxane unit represented above, and each R is the same. It may be a functional group or a different functional group.)

  Depending on the type of the substituent in the general formula (1), the polysiloxane may have a linear, cyclic, network, ladder, or cage structure, and any of the polysiloxanes used in the present invention may be used. .

  Another example of the polysiloxane compound used in the present invention includes one having a structure as shown in the following general formula (3).

In the formula, each of R _{9 to} R ₁₂ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an alkenyl group, or a substituted or unsubstituted phenyl group. Each of R _{9 to} R ₁₂ may be the same or different. r and p are integers of 0 or more, and the sum of r and p is an integer of 1 or more.

  The polysiloxane compound used in the present invention particularly preferably has at least a specific silsesquioxane skeleton as shown in the following general formula (2).

In the formula, R _{5 to} R ₈ are either a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms or a substituted or unsubstituted phenyl group. Each of R _{5 to} R ₈ may be the same or different. m and n are integers of 0 or more, and the sum of m and n is an integer of 1 or more. The form of copolymerization may be random copolymerization or block copolymerization.

Specific examples of R _{5 to} R ₈ include a substituted phenyl group such as an unsubstituted alkyl group such as a methyl group or an ethyl group / an unsubstituted phenyl group / a dimethylphenyl group or a naphthyl group. . Further, the substituents R _{5 to} R ₈ may contain various atoms such as oxygen atom, nitrogen atom and metal atom in addition to carbon atom and hydrogen atom.

A siloxane compound having both the structure represented by the general formula (2) and the structure represented by the general formula (3) can also be used in the present invention.
The silsesquioxane skeleton in the present invention will be described. In the general formula (2), m cissesquioxane units (hereinafter referred to as first units) having substituents R ₅ and R ₆ and cissesquioxane units having substituents R ₇ and R ₈ are repeated. The following shows a structure in which n (second unit) repeats are connected. Note that m and n are integers of 0 or more, and m + n is an integer of 1 or more. However, this does not mean that the repetition of the first unit and the repetition of the second unit are separated. Both units may be connected separately or may be connected randomly.

  Examples of the method for forming a crystallization promoting layer in the present invention mainly using a compound having a specific silsesquioxane skeleton as shown in the general formula (2) include the following. That is, a solution containing the polyorganosilsesquioxane compound represented by the following general formula (7) and general formula (8) or one of them may be applied on a substrate, heated and dried.

  At that time, a preferable heat treatment temperature is 140 ° C. or higher, more preferably 150 ° C. or higher and 230 ° C. or lower. If it is heated below 140 ° C., the hydrolysis reaction may be insufficient.

In the formula, R ₅ and R ₆ are either a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms or a substituted or unsubstituted phenyl group, and R ₅ and R ₆ are the same functional group. Also good. R _{27 to} R ₃₀ are an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and z is an integer of 1 or more.

In the formula, R ₇ and R ₈ are either a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms or a substituted or unsubstituted phenyl group, and R ₇ and R ₈ are the same functional group. Also good. R _{31 to} R ₃₄ are an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and y is an integer of 1 or more.

  By such heating and drying, a hydrolysis reaction is induced at the end of the compound, and the silsesquioxane compound as a raw material is connected in a ladder shape and densified. However, at this time, the heating and drying temperatures are not so high that the organic substances completely disappear, so that the raw material compound does not have a complete silica structure but a silsesquioxane skeleton in which most of the substituents remain. . It can be said that not having a complete silica structure is one point for obtaining a good semiconductor layer.

In addition, a small amount of acid such as formic acid may be added to the coating solution for the purpose of assisting the reaction in which the oligomeric silsesquioxane compounds cross-link each other during the drying step.
The amount of acid added is not particularly limited. When formic acid is used as the acid, it is preferable to add it in the range of 1 to 30% by weight with respect to the solid content weight of the polyorganosilsesquioxane compound contained in the coating solution because the crosslinking reaction is promoted. If the addition amount is less than 1% by weight, the effect of promoting the crosslinking reaction may be insufficient, and conversely if the addition amount is more than 30% by weight, the film properties after drying may be impaired.

In the process of cross-linking reaction and solvent removal, the stabilizer that does not evaporate, volatilize or burn out in the temperature region is removed from the solution system as much as possible.
Arbitrary things, such as alcohol and ester, can be used for the solvent of a coating solution. A solvent may be selected in consideration of wettability to the substrate.

  The method for applying the raw material solution for the polysiloxane compound layer or the crystallization promoting layer is not particularly limited. As a coating method, a conventional coating method such as a spin coating method, a casting method, a spray coating method, a doctor blade method, a die coating method, a dipping method, a printing method, an ink jet method, a dropping method and the like can be employed. Examples of printing methods include screen printing, offset printing, gravure printing, flexographic printing, and micro contact printing. Among these coating methods, a preferable method in that a film can be formed with a desired film thickness by controlling the coating amount is a spin coating method, a dipping method, a spray coating method, or an ink jet method. Further, in order to maintain the insulating properties of the obtained film, it is important that dust and the like are not mixed in the coating solution as much as possible, and it is desirable to filter the raw material solution with a membrane filter in advance.

  The liquid concentration is preferably adjusted so that the thickness of the polysiloxane compound layer or the crystallization promoting layer is 10 nm or more, preferably 15 nm or more and 500 nm or less. This is because if the thickness is less than 10 nm, it may be difficult to obtain a uniform film.

Before applying the polysiloxane compound layer or the crystallization promoting layer, the surface of the substrate may be modified by ultrasonic treatment with an alkaline solution or UV irradiation to improve the wettability of the substrate surface.
Next, the organic semiconductor precursor used in the present invention will be described. The organic semiconductor precursor preferably has at least one selected from bicyclo structures represented by the following general formulas (4) and (5) as a partial structure in the molecule.

In the formula, R ₁₃ and R ₁₄ are either an oxygen atom, a sulfur atom, or NR ₁₅ . Here, R ₁₅ represents at least one selected from linear or branched alkyl groups having 1 to 12 carbon atoms, alkenyl groups, alkoxy groups, alkylthio groups, alkyl ester groups, aryl groups, and hydroxyl groups.

(In the formula, R ₁₆ represents an oxygen atom or a sulfur atom.)
Furthermore, it is preferable that the organic semiconductor precursor having a bicyclo structure represented by the general formula (4) and the general formula (5) is converted into an acene-based compound by light, and in particular, the structure represented by the general formula (6). Is more preferable.

In formula, A ring shows either the bicyclo ring shown by the said General formula (4) or (5). R ₁₇ and R ₁₈ represent a hydrogen atom, an alkyl group, an alkoxy group, an ester group or a phenyl group. R ₁₉ to R _{26 each} represents a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, a heterocyclic group, an aralkyl group, a phenoxy group, a cyano group, a nitro group, an ester group, a carboxyl group, or a halogen atom.

  The aryl group here is a monovalent monocyclic or polycyclic aromatic hydrocarbon group, and the polycyclic aromatic hydrocarbon is, for example, naphthalene, anthracene, azulene, heptalene, biphenylene, indacene, acenaphthylene. , Phenanthrene, triphenylene, pyrene, chrysene, picene, perylene, pentaphen, rubicene, coronene, pyranthrene, ovarene and the like condensed from 2 to 15 aromatic hydrocarbon rings. The condensed positions of 2 to 15 rings may be condensed anywhere other than those exemplified in the examples. The heterocyclic group is a monovalent pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, pyrrole ring, imidazole ring, pyrazole ring, furan ring, thiophene ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring. And a condensed heterocyclic group in which a monocyclic heterocyclic group such as a furazane ring and a selenophene ring, a monocyclic heterocyclic ring, and an aromatic hydrocarbon ring are arbitrarily combined and condensed. The aryl group and the heterocyclic group may have a substituent, and may be substituted at any position as long as they can be substituted. Furthermore, oligomers may be formed by combining aryl groups, hetero groups, and aryl groups and heterocyclic groups.

R ₁₇ , R ₁₈ , R ₁₉ to R ₂₆ may be the same or different. R ₂₀ and R ₂₁ , R ₂₄ and R ₂₅ may be connected to each other to form an A ring or a 5-membered or 6-membered heterocyclic ring. Here, as the 5-membered or 6-membered heterocyclic ring, for example, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, pyrrole ring, imidazole ring, pyrazole ring, furan ring, thiophene ring, oxazole ring, isoxazole ring, thiazole ring , Isothiazole ring, furazane ring, and selenophene ring. t, u and v are integers of 0 or more. The sum of t to v is an integer of 1 or more.

  Among them, a structure that can be converted to an acene compound by light, a structure that can be converted by light to an oligomer in which two or six of the same or different acene compounds are connected, and a heterocyclic ring is connected to the acene compound. More preferred are those that are converted to light by light. The acene-based compound is a compound in which three or more rings selected from an aromatic hydrocarbon ring or a heterocyclic ring are linearly condensed, such as anthracene, tetracene, pentacene, acridine, and thianthrene.

  Here, when energy is imparted to the organic semiconductor precursor having the bicyclo skeleton represented by the general formula (4) and the general formula (5) as a partial structure, the bicyclo skeleton receives the imparted energy and receives a reverse Diels-Alder. Cause a reaction. Specifically, as shown in Reaction Formula (1) and Reaction Formula (2), the bicyclo skeleton is converted into an aromatic ring. Accordingly, the organic semiconductor precursor is changed to an organic semiconductor.

  Here, the Diels-Alder reaction is an organic chemical reaction in which a double bond called dienophile is added to a conjugated diene to form a cyclic structure. The reverse Diels-Alder reaction is a reverse reaction of the Diels-Alder reaction, in which the formed cyclic structure is converted into a conjugated diene and a dienophile.

In the bicyclo skeleton represented by the general formula (4), as shown in the reaction formula (1), a unit of R ₁₃ = C = C = R ₁₄ is eliminated by light, and the bicyclo skeleton changes from an aromatic ring to a bicyclo skeleton. When the unit of R ₁₃ = C = C = R ₁₄ is an unstable structure, R ₁₃ = C = C = R ₁₄ may be converted into a more stable structure. Therefore, R ₁₃ and R ₁₄ are selected from the viewpoint of whether R ₁₃ = C = C = R ₁₄ can be eliminated by light. R ₁₃ and R ₁₄ are preferably either an oxygen atom, a sulfur atom or NR ₁₅ . Here, R ₁₅ represents at least one selected from linear or branched alkyl groups having 1 to 12 carbon atoms, alkenyl groups, alkoxy groups, alkylthio groups, alkyl ester groups, aryl groups, and hydroxyl groups. When the number of carbon atoms in R ₁₅ exceeds 12, the molecular weight of the desorbing component increases and may remain in the generated organic semiconductor. In such a case, sufficient semiconductor characteristics cannot be obtained. More preferably, R ₁₅ has 6 or less carbon atoms. More preferably, R ₁₃ and R ₁₄ are both oxygen atoms.

In the bicyclo skeleton represented by the general formula (5), as shown in the reaction formula (2), the unit of CH ₂ ═C═R ₁₆ is eliminated by light and changes from the bicyclo skeleton to an aromatic ring. When the unit of CH ₂ = C = R ₁₆ is an unstable structure, CH ₂ = C = R ₁₆ may be converted into a more stable structure. Therefore, R ₁₆ is selected from the viewpoint of whether CH ₂ ═C═R ₁₆ can be eliminated by light. R ₁₆ is preferably an oxygen atom or a sulfur atom.

Preferred examples of the organic semiconductor precursor used in the present invention are shown below.
In the examples, an α-diketone structure is shown as a bicyclo structure, but the structure is not limited to this, and an unsubstituted structure is mainly shown, but if possible, it has a substituent. May be. The compound shown here is only an example, and the compound of the present invention is not limited thereto.

  These organic semiconductor precursors are applied on the substrate on which the crystallization promoting layer is formed. Thereby, an organic semiconductor precursor layer is formed. At this time, it is desirable that the polysiloxane compound layer or the crystallization promoting layer and the organic semiconductor precursor layer are laminated in close contact. Adhesion refers to a state in which at least a part of the polysiloxane compound layer or crystallization promoting layer and at least a part of the organic semiconductor precursor layer are in contact with each other without any other layer.

  As a method for forming the organic semiconductor precursor layer, a method of coating after dissolving the organic semiconductor precursor in an organic solvent is preferable. The organic solvent used for dissolving the organic semiconductor precursor is not particularly limited as long as the organic semiconductor material does not react or precipitate. Two or more organic solvents may be mixed and used. Here, it is desirable to select a solvent taking into consideration the smoothness of the coating film surface and the uniformity of the film thickness.

  Examples of solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, hexane, heptane, cyclohexane, tetrahydrofuran, dioxane, diethyl ether, isopropyl ether, dibutyl ether, toluene, xylene, 1,2-dimethoxyethane, chloroform, methylene chloride. Dichloroethane, 1,2-dichloroethylene, dimethyl sulfoxide, N-methylpyrrolidone, chlorobenzene, dichlorobenzene, trichlorobenzene, and the like. The concentration of the solution is arbitrarily adjusted depending on the desired film thickness, but is preferably 0.01% by weight or more and 5% by weight or less.

  The application method is not particularly limited. Examples of the coating method include conventional coating methods such as spin coating, casting, spray coating, doctor blade method, die coating method, dipping method, printing method, ink jet method, and dropping method. Examples of printing methods include screen printing, offset printing, gravure printing, flexographic printing, and micro contact printing. Among these coating methods, preferred coating methods are a spin coating method, a dipping method, a spray coating method, and an ink jet method in that a film having a desired film thickness can be formed by controlling the coating amount. Further, it is desirable to filter with a filter in advance so as not to mix dust and the like into the coating film as much as possible. This is because insoluble matters and dust from the outside prevent uniform orientation and may cause an increase in off current and a decrease in on / off ratio. The organic semiconductor precursor coating can also be pre-dried.

  As described above, the organic semiconductor precursor layer is formed on the polysiloxane compound layer or the crystallization promoting layer. Then, by applying light energy and thermal energy simultaneously, the bicyclo skeleton is converted to an aromatic ring (precursor to organic semiconductor). Simultaneously with the conversion to the aromatic ring, crystal growth by stacking of organic semiconductors occurs simultaneously, and an organic semiconductor crystallized film is formed. Thereby, a layer made of an organic semiconductor is formed.

  Light energy is provided by irradiating the organic semiconductor precursor layer with light. Although the wavelength of the light to irradiate should just be the absorption wavelength area | region which an organic-semiconductor precursor has, More preferably, it is a wavelength area | region of 300 to 500 nm. If the wavelength is shorter than 300 nm, there is a concern about damage to the peripheral portion or side reaction, and if the wavelength is 500 nm or more, there is a concern about damage to the obtained organic semiconductor. As the light source, a tungsten lamp, a halogen lamp, a metal halide lamp, a sodium lamp, a xenon lamp, a high-pressure mercury lamp, a low-pressure mercury lamp, various laser lights, and the like are selected. The light irradiation method is not particularly limited as long as the organic semiconductor precursor is changed to an organic semiconductor. However, in view of performing a photoreaction more effectively, a method of directly irradiating the organic semiconductor precursor is desirable. However, when heat generated by light irradiation is applied to the organic semiconductor precursor, it is preferable to cut the heat with a heat absorption filter or the like.

Patterning can also be performed by performing light irradiation through a mask.
Thermal energy is provided by heating the substrate from the outside. As a heating method, any method may be used, and a preferable method is a method of heating on a hot plate in a hot air circulation type oven or a vacuum oven. A more preferable method in the present invention is a method of heating the substrate on a hot plate. The optimum heating temperature differs depending on the organic semiconductor precursor, but considering the influence on the peripheral portion, etc., heating in a temperature range of 50 ° C. or higher and 180 ° C. or lower is preferable.

  The time for applying light energy and thermal energy at the same time varies greatly depending on the film thickness, material, etc., and cannot be determined in general. Generally, as the organic semiconductor crystallized film grows, light transmission to the deep part of the film becomes difficult. Therefore, it is preferable that the time for simultaneously applying light energy and heat energy is 1 second to 30 minutes. By doing in this way, light can be used effectively for conversion from a precursor to an organic semiconductor. More preferably, the time for applying light energy and heat energy simultaneously is 1 minute to 15 minutes.

  According to detailed studies by the present inventors, it is important to obtain light and thermal energy simultaneously in order to obtain an excellent crystallized film. Even if only the light energy is applied to the organic semiconductor precursor film, the elimination reaction itself proceeds. However, an organic semiconductor film that has undergone a desorption reaction by applying only light energy to the organic semiconductor precursor thin film is an amorphous film, and sufficient semiconductor characteristics cannot be obtained. In addition, semiconductor properties can be obtained when thermal energy is applied after desorption reaction with only light energy applied, but sufficient semiconductor properties are obtained because crystallization takes time or is not sufficient. It may not be possible. This means that when a sample that has been subjected to a desorption reaction by applying only light energy to the organic semiconductor precursor thin film is left in the atmosphere, the characteristic color of the organic semiconductor after conversion gradually fades and deteriorates. In contrast, the sample that had undergone a desorption reaction with simultaneous application of light energy and heat energy did not fade the color peculiar to organic semiconductors even when left in the atmosphere for more than 10 days. Is also instructed. This is because heating by thermal energy works to fill the gaps in the crystal grains generated by the elimination reaction, leading to a more stable crystal state in which the organic semiconductor layer is less susceptible to oxygen and moisture intrusion. This is probably because In the examples described later, the effect of the present invention is verified by taking a field effect transistor as an example. However, it is considered that the effect of the present invention, which is an improvement in durability due to stabilization of the crystalline state, is valid not only for field effect transistors but also for semiconductor devices in general.

  The film thickness of the organic semiconductor film obtained by these operations is preferably 10 nm or more and 500 nm or less, more preferably 20 nm or more and 300 nm or less. The film thickness can be measured with a surface roughness meter or a step meter.

  Furthermore, according to the detailed examination by the present inventors, it is possible to simultaneously apply light energy and thermal energy to the organic semiconductor precursor on the crystallization promoting layer, and to convert the organic semiconductor precursor into a layer composed of the organic semiconductor. It is considered important to maximize In general, it is observed that when an organic semiconductor precursor is subjected to a desorption reaction by simultaneously applying light energy and thermal energy to form an organic semiconductor, a gap is formed between crystal grains made of the obtained compound. . On the other hand, when such a reaction was performed on the crystallization promoting layer, it was confirmed that the gap between the crystal grains of the organic semiconductor layer was filled and a uniform crystal was formed over the entire substrate.

This is presumably because the crystallization promoting layer promotes stabilization of the crystal grains of the organic semiconductor layer (which may involve movement and rotation) and bonding of the crystal grains.
The present inventor believes that the crystallinity of the organic semiconductor layer is improved by the action of the crystallization promoting layer as a function of the crystallization promoting layer. Note that it is particularly preferable that the crystal grains are bonded to each other.

  A schematic cross-sectional view of the organic field effect transistor of the present invention is shown in FIG. The field effect transistor of the present invention comprises a gate electrode 1, an insulating layer 2, an A layer 3 (polysiloxane compound layer or crystallization promoting layer), a source electrode 4, a drain electrode 5, and a B layer 6 (organic semiconductor layer). Is done.

  The gate electrode, source electrode, and drain electrode are not particularly limited as long as they are conductive materials. Platinum, gold, silver, nickel, chromium, copper, iron, tin, antimony lead, tantalum, indium, aluminum, zinc, magnesium , And alloys thereof, conductive metal oxides such as indium / tin oxide, or inorganic and organic semiconductors whose conductivity has been improved by doping, such as silicon single crystal, polysilicon, amorphous silicon, germanium, graphite, Examples include polyacetylene, polyparaphenylene, polythiophene, polypyrrole, polyaniline, polythienylene vinylene, polyparaphenylene vinylene, and the like. Examples of the method for producing the electrode include a sputtering method, a vapor deposition method, a printing method from a solution and a paste, an ink jet method, and a dipping method. Further, among the electrode materials mentioned above, those having low electric resistance at the contact surface with the semiconductor layer are preferable.

  As the insulating layer, any material can be used as long as the A layer can be applied uniformly. Examples include inorganic oxides and nitrides such as silicon oxide, silicon nitride, aluminum oxide, titanium oxide, and tantalum oxide, polyacrylate, polymethacrylate, polyethylene terephthalate, polyimide, polyether, and the like. Among the insulating materials, those having high surface smoothness are preferable. In addition, since the A layer itself is excellent in insulation, the A layer itself may be used as the gate insulating layer by adjusting the thickness of the A layer to a thickness at which the insulation is expressed.

  The field effect transistor structure in the present invention may be any of a top contact electrode type, a bottom contact electrode type, and a top gate electrode type. Moreover, it is not limited to a horizontal type, A vertical type may be sufficient.

The present invention will be specifically described below with reference to examples.
Synthesis example 1
First, a synthesis example of a bicyclo compound used in the present invention will be described by taking 6,13-Dihydro-6,13-ethanolpentene-15,16-dione as an example.

(Process 1)
In a reaction vessel, 5,6,7,8-tetramethylidenebicyclo [2,2,2] oct-2-ene (12 mmol, 1.91 g) and isoamyl nitrite (75 mmol, 10.0 ml) were added to THF (tetrahydrofuran). It was dissolved in 80 ml and heated to reflux. A solution prepared by dissolving anthranilic acid (91 mmol, 12.5 g) in 100 ml of THF was added to the dropping funnel and slowly dropped. After dripping, heating and stirring were continued until the raw material disappeared. After completion of the reaction, an aqueous sodium hydroxide solution was added and stirring was continued, and the reaction solution was extracted with hexane. The obtained organic layer was washed with water and saturated brine, dried over anhydrous sodium sulfate and concentrated to obtain a crude product. This was purified by silica gel column chromatography (hexane) to obtain a compound represented by the following general formula (9). The yield was 2.66 g, and the yield was 72%.

Molecular formula: C ₂₄ H ₂₀ (308.42)
Shape: white crystal 1H NMR (CDC1 ₃ ) δ = 7. 10 (4H, s), 6.85 (4H, ~ J = 3.41), 4.29 (2H, t, J = 3.41), 3.60 (8H, s) [270 MHz]
13C NMR (CDC1 ₃ ) δ = 140.179, 139.254, 134.241, 128.715, 125.858, 54.197, 33.164
[67.8MHz]
Mass spectrum (FAB) m / z: 308 (M +: 22)
Elemental analysis: Calcd (%) C = 93.46, H = 6.54
Found (%) C = 93.54, H = 6.68,

(Process 2)
The compound obtained in Step 1 (4.02 mmol, 1.24 g) was placed in a reaction vessel and dissolved in 50 ml of chloroform. DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone) (8.04 mmol, 1.80 g) was added to this solution and stirred for 2 hours. The organic layer was washed well with saturated aqueous sodium hydrogen carbonate, washed with water and saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain a crude product. This was purified by silica gel column chromatography (10% ethyl acetate / hexane) to obtain a compound represented by the following general formula (10).

Yield 1.20 g, 98% yield
Molecular formula: C ₂₄ H ₁₆ (304.38)
Melting point: 277.2 ° C
Shape: white crystal 1H NMR (CDC1 ₃ ) δ = 7.72 (4H, s), 7.69 (4H, m), 7.37 (4H, m), 7.04 (2H, q, J = 3) .42, 0.98), 5.32 (2H, m)
[270 MHz]
13C NMR (CDC1 ₃ ) δ = 142.13, 138.24, 131.68, 127.42, 125.52, 121.23, 50.15
[67.8MHz]
Infrared absorption spectrum (KBr) cm ⁻¹ : 3054, 2973
Mass spectrum (DIEI) m / z: 304 (M +: 100), 278 (13)
Elemental analysis: Calcd (%) C = 94.70, H = 5.30
Found (%) C = 94.36, H = 5.58

(Process 3)
A 1 L eggplant-shaped flask was charged with NMO (N-methylmorpholine-N-oxide) .H ₂ O (5.60 mmol, 0.78 g) and a rotor, and purged with argon. Furthermore, 500 ml of acetone was added, and OsO ₄ (0.10 mmol, 5 ml) was added. The compound obtained in Step 2 (4.11 mmol, 1.25 g) was added and the mixture was flat-plugged, and stirred vigorously for 32 hours while maintaining the room temperature. Na ₂ S ₂ O ₄ (0.6 g) water was added and stirred for 10 minutes, followed by Celite filtration and extraction of the mother liquor with ethyl acetate. The obtained organic layer was washed with water and saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain 6,13-Dihydro-15,16-dihydroxy-6,13-ethanolpentene as white crystals.

Yield 1.36 g, 98% yield
Molecular formula: C ₂₄ H ₁₈ O ₂ (338.40)
Melting point: 299.8 ° C
Shape: white crystal 1H NMR (CDC1 ₃ ) δ = 7.85 (2H, s), 7.80 (8H, m), 7.43 (4H, m), 4.66 (2H, s), 4. 22 (2H, s)
[270 MHz]
13C NMR (CDC1 ₃ ) δ = 137.349, 135, 876, 132, 722, 127.574, 125.876, 125.813, 125.220, 123.324, 68.411, 51.187
[100.4MHz]
Infrared absorption spectrum (KBr) cm ⁻¹ : 3432.67, 370.68 (OH)
Mass spectrum (FAB) m / z: 339 (M +: 4)
Elemental analysis: Calcd (%) C = 62.15, H = 4.69
Found (%) C = 62.01, H = 4.75

(Process 4)
In a three-necked reaction vessel under an inert gas atmosphere, dry-DMSO (dimethyl sulfoxide) (132 mmol, 9.4 ml) and dry-CH ₂ C1 ₂ 69 ml were added and cooled to −60 ° C. with an acetone / liquid nitrogen bath. . While maintaining the liquid temperature at −60 ° C., 119 mmol of trifluoroacetic anhydride (16.5 ml) was slowly added dropwise and stirred for 10 minutes. Thereafter, 6,13-Dihydro-15,16-dihydroxy-6,13-ethanolpentene (3.81 mmol, 1.29 g) dissolved in a minimum amount of dry-DMSO (dimethyl sulfoxide) was slowly added dropwise, Stir for 15 hours. While maintaining the liquid temperature at −60 ° C., triethylamine (275 mmol, 10.7 ml) was added dropwise, followed by stirring for 1.5 hours. The reaction solution was slowly poured into 2M HCl (200 ml) and extracted with CH ₂ C 1 ₂ . The obtained organic layer was washed with ion exchanged water and saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain a crude product. Ethyl acetate was added thereto, and the insoluble material was collected by filtration to obtain 6,13-Dihydro-6,13-ethanolpentene-15,16-dione.

Yield 0.55g, Yield 43%
Molecular formula: C ₂₄ H ₁₄ O ₂ (334.37)
Melting point: 318 ° C to 323 ° C
Shape: yellow crystal 1H NMR (CDC1 ₃ ) δ = 7.94 (4H, s), 7.84 (4H, m), 7.52 (4H, m), 5.31 (2H, s)
[270 MHz]
13C NMR (CDC1 ₃ ) δ = 185.165, 133.585, 131.851, 127.862, 1277.017, 125.364, 60603
[67.8MHz]
Infrared absorption spectrum (KBr) cm ⁻¹ : 1754.90, 1735.62 (C═O)
Mass spectrum (DIEI) m / z: 335 (M +: 4)
Elemental analysis: Calcd (%) C = 86.21, H = 4.22
Found (%) C = 86.41, H = 4.40

Synthesis example 2
In the synthesis method of 6,13-Dihydro-6,13-ethanepentene-15,16-dione exemplified in Synthesis Example 1, a synthesis method different from Synthesis Example 1 is shown below.

(Process 1)
Pentacene (1.39 g, 5.0 mmol), vinylene carbonate (0.32 g, 5.0 mmol), and xylene (95 ml) were placed in an autoclave and stirred at 180 ° C. for 72 hours. After the reaction, the compound represented by the following general formula (11) was obtained by concentration and drying under reduced pressure (1.78 g, 98%).

Process (2)
The compound (1 g, 2.7 mmol) obtained in the step (1) was put in a reaction vessel and dissolved in 1,4-dioxane (30 ml). (4M) NaOH (11.3 ml) was added thereto, and the mixture was refluxed for 1 hour. After completion of the reaction, the reaction product was poured into water and extracted with ethyl acetate. The organic layer was washed with water and saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. Thus, 6,13-Dihydro-15,16-dihydroxy-6,13-ethanolpentene, which was the target product, was obtained (0.91 g, 100%).

Step (3)
The reaction vessel was purged with nitrogen, and dimethyl sulfoxide (8.6 ml, 93.5 mmol) and methylene chloride (48 ml) were added. The reaction vessel was cooled to −60 ° C., trifluoroacetic anhydride (11.7 ml, 84.3 mmol) was added, and the mixture was stirred for 10 minutes. After stirring, the reaction was performed by dissolving 6,13-Dihydro-15,16-dihydroxy-6,13-ethanolpentene (0.96 g, 2.7 mmol) obtained in step (2) in dimethyl sulfoxide (4 ml). Slowly dropped into the solution. After the dropwise addition, the mixture was stirred at -60 ° C. for 1.5 hours, and triethylamine (27.5 ml) was added. The mixture was further stirred for 1.5 hours and then returned to room temperature. The reaction solution was poured into 150 ml of 10% hydrochloric acid and extracted with methylene chloride. The organic layer was washed with water and saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The obtained crude product was washed with ethyl acetate to obtain the desired product, 6,13-Dihydro-6,13-ethanolpentene-15,16-dione (0.45 g, 50%).

Synthesis example 3
Next, dibromo-6, 13-dihydro-6, 13-ethenepentene-15, 16-dione will be described as an example.

(Process 1)
2,6-Dibromoanthracene (2.41 mmol, 0.67 g), vinylene carbonate (3.80 mmol, 0.21 ml) and anhydrous xylene (10 ml) were placed in an autoclave and reacted at 180 ° C. for 3 days. Then, it returned to room temperature and concentrated under pressure reduction. The obtained crude product was purified by silica gel column chromatography. As a result, 2,6-dibromo-9,10-dihydro-9,10-ethanolanthracene-cis-11,12-diyl carbonate was obtained (0.73 g, 72%).

(Process 2)
2,6-dibromo-9,10-dihydro-9,10-ethananthracene-cis-11,12-diyl carbonate (0.58 mmol, 0.24 g) obtained in Step 1; literature (K. Ito, T. et al. Boronic tes obtained by the method described in Suzuki, Y. Sakamoto, D. Kubota, Y. Inoue, F. Sato, S. Tokyo, Angew. Chem. Int. Ed. 2003, 42, 1159 to 1162. 1.33mmol, 0.40g), tetrakis (triphenylphosphine ) palladium (0) (0.066mmol, 0.077g), toluene _{(202ml), 1N Na 2 CO} 3 (8.5ml) and the flask Put, purged with nitrogen, and the mixture was refluxed for 18 hours. Then, after returning to room temperature, cerite filtration was carried out, and the residue was washed with toluene. Thereafter, the filtrate was concentrated under reduced pressure, and the resulting crude product was purified by silica gel chromatography. As a result, 2,6- (2′-Anthryl) -9,10-dihydro-9,10-ethanolanthracene-cis-11,12-diyl carbonate, which was the target product, was obtained (0.089 g, 25%). .

(Process 3)
2,6- (2′-Anthryl) -9,10-dihydro-9,10-ethanolanthracene-cis-11,12-diyl carbonate (0.11 mmol, 0.067 g) obtained in Step 4 was added to 4N NaOH ( 2 ml) and 1,4-dioxane (4 ml) and purged with nitrogen. Thereafter, the mixture was refluxed for 1 hour and returned to room temperature. Water was added thereto and extracted with chloroform. The organic layer was washed with water and saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain a diol. The obtained diol was subjected to Swern oxidation in the same manner as in Synthesis Example 1 (Step 4). As a result, 2,6-Dianthryl-9,10-dihydro-9,10-ethanolanthracene-11,12-dione, which was the target product, was obtained (0.046 g, 69%).

Preparation of Resin Solution a Dissolve 1.0 g of commercially available flaky methylsilsesquioxane (MSQ) (trade name GR650, manufactured by Showa Denko) in a mixed solvent consisting of 49.5 g of ethanol and 49.5 g of 1-butanol. Thus, a resin solution a was prepared.

Preparation of Resin Solution b 1.0 g of methyltrimethoxysilane was completely dissolved in a mixed solvent consisting of 49.5 g of ethanol and 49.5 g of 1-butanol. To this solution, 0.83 g of distilled water and 0.05 g of formic acid were added and stirred at room temperature for 48 hours to prepare silica sol b.

Example 1
FIG. 1 shows a structure of a top electrode type field effect transistor in this embodiment.
First, a highly doped N-type silicon substrate was used as the gate electrode 1. A 5000-inch silicon oxide film obtained by thermally oxidizing the surface layer of the silicon substrate was used as the gate insulating layer 2. Next, the resin solution a was applied to the surface of the insulating layer by spin coating (rotation speed: 5000 rpm). Next, this coating film was transferred to a hot plate and heated at 100 ° C. for 5 minutes and at 220 ° C. for 30 minutes. In this way, A layer 3 (polysiloxane layer) was formed.

  Next, a 1.0 wt% chloroform solution of 6,13-Dihydro-6,13-ethanolpentene-15,16-dione synthesized in Synthesis Example 1 is spin-coated on the substrate on which the A layer 3 is thus formed. It was applied by the method. The rotation speed was 1000 rpm. Thereby, a coating film was formed. Furthermore, the substrate on which the coating film is formed in this way is placed on a hot plate set at 120 ° C., passed through a heat absorption filter and a blue filter, and the light of a metal halide lamp (PCS-UMX250) manufactured by Nippon P.I. Irradiated for 5 minutes. Thereby, B layer 6 (organic semiconductor layer) was formed.

On the B layer 6, Au was evaporated using a mask to form the source electrode 4 and the drain electrode 5. The electrode was prepared under the conditions that the degree of vacuum in the vapor deposition apparatus chamber was 1 × 10 ⁻⁶ torr and the substrate temperature was room temperature. Moreover, the film thickness of the obtained electrode was 100 nm.

A field effect transistor having a channel length L = 50 μm and a channel width W = 3 mm was produced by the above procedure. V _d -I _d and V _g -I _d curves of the prepared transistor were measured using a parameter analyzer 4156C (trade name) manufactured by Agilent.

The mobility μ (cm ² / Vs) was calculated according to the following formula (1).

Here, Ci is the capacitance per unit area of the gate insulating film (F / cm ² ), and W and L are the channel width (mm) and channel length (μm) shown in the examples, respectively. I _d , V _g , and V _th are a drain current (A), a gate voltage (V), and a threshold voltage (V), respectively. In addition, the ratio of V _g = -80 V and 0V of I _d in V _d = -80 V as the on / off ratio. The field effect mobility calculated from the obtained results was 0.18 cm ² / Vs. The on / off ratio was 1.5 × 10 ⁵ .

(Example 2)
Four elements were produced in the same manner as in Example 1 except that the resin solution a used in Example 1 was changed to the resin solution b, and the same electrical characteristics evaluation as in Example 1 was performed. The field effect mobility calculated from the obtained result was 0.34 cm ² / Vs. The on / off ratio was 2.0 × 10 ⁶ .

(Example 3 and Comparative Example 1)
A 1.5 wt% chloroform solution of 6,13-Dihydro-6,13-ethanolpentene-15,16-dione was developed on two quartz glasses to form a film. One of them passed through a heat absorption filter and a blue filter on a hot plate set at 120 ° C., and was irradiated with light from a metal halide lamp (PCS-UMX250) manufactured by Nippon P.I. The other was passed through a heat absorption filter and a blue filter at room temperature, and irradiated with light from a metal halide lamp (PCS-UMX250) manufactured by Nippon P.I. At this time, both of the two samples changed to the blue color peculiar to pentacene. In this way, an organic semiconductor film formed by applying light and heat simultaneously and an organic semiconductor film formed by applying only light were obtained. When these two samples were left in the atmosphere for 10 days and the color of the film was confirmed again, the organic semiconductor film formed by applying light and heat simultaneously remained blue. On the other hand, the organic semiconductor film formed by applying only light has faded.

(Comparative Example 2)
On a highly doped N-type silicon substrate with a silicon oxide film similar to that in Example 1, a 1.0 wt% chloroform solution of 6,13-Dihydro-6,13-ethanolpentene-15,16-dione synthesized in Synthesis Example 1 was added. The coating was performed by a spin coating method. The rotation speed was 1000 rpm. Thereby, a coating film was formed. Furthermore, the substrate on which the coating film is formed in this way is placed on a hot plate set at 120 ° C., passed through a heat absorption filter and a blue filter, and the light of a metal halide lamp (PCS-UMX250) manufactured by Nippon P.I. Irradiated for 5 minutes. Thereby, B layer 6 (organic semiconductor layer) was formed.

On the B layer 6, Au was evaporated using a mask to form the source electrode 4 and the drain electrode 5. The electrode was prepared under the conditions that the degree of vacuum in the vapor deposition apparatus chamber was 1 × 10 ⁻⁶ torr and the substrate temperature was room temperature. Moreover, the film thickness of the obtained electrode was 100 nm. It confirmed that it changed from the yellow layer which is a precursor layer to the blue layer which is a pentacene layer after light irradiation. On top of that, gold was deposited using a mask to form a source electrode 4 and a drain electrode 5.

A field effect transistor having a channel length L = 50 μm and a channel width W = 3 mm was formed on the same substrate by the above procedure, and the same electrical characteristics evaluation as in Example 1 was performed. The field effect mobility calculated from the obtained result was 0.098 cm ² / Vs. The on / off ratio was 1.3 × 10 ⁴ .

(Comparative Example 3)
The same operation as in Example 1 was performed until the A layer was formed. On this board | substrate, it apply | coated by the spin coat method from the 1.0 weight% chloroform solution of 6,13-Dihydro-6,13-ethanepentene-15,16-dione. The rotation speed was 1000 rpm. Thereby, a coating film was formed. Further, the substrate on which the coating film was formed was irradiated with light from a metal halide lamp (PCS-UMX250) manufactured by Nippon P-I Co., Ltd. for 15 minutes through a heat absorption filter and a blue filter. Here, it confirmed that it changed from the yellow layer which is a precursor layer to the blue layer which is a pentacene layer. On top of this, gold was deposited through a mask to form a source electrode 4 and a drain electrode 5.

  A field effect transistor having a channel length L = 50 μm and a channel width W = 3 mm was formed on the same substrate by the above procedure, and the same electrical characteristics evaluation as in Example 1 was performed. However, no semiconductor characteristics were obtained.

(Comparative Example 4)
The same operation as in Example 1 was performed until the A layer was formed. On this board | substrate, it apply | coated by the spin coat method from the 1.0 weight% chloroform solution of 6,13-Dihydro-6,13-ethanepentene-15,16-dione. The rotation speed was 1000 rpm. Thereby, a coating film was formed. Further, the substrate on which the coating film was formed was passed through a heat absorption filter and a blue filter, and irradiated with light from a metal halide lamp (PCS-UMX250) manufactured by Nippon P-I Co., Ltd. for 15 minutes at room temperature, and then set to 120 ° C. Heat on hot plate for 15 minutes. Here, it confirmed that it changed from the yellow layer which is a precursor layer to the blue layer which is a pentacene layer. On top of this, gold was deposited through a mask to form a source electrode 4 and a drain electrode 5. The field effect mobility calculated from the obtained results was 3.4 × 10 ⁻⁴ cm ² / Vs. The on / off ratio was 5.0 × 10 ² .

  From these results, since the field effect transistor according to the example of the present invention forms a film having excellent crystallinity and orientation, the mobility and stability of the film are different from those of the field effect transistor according to the comparative example. It turns out that it is superior.

  Since the semiconductor element obtained by the manufacturing method of the present invention has little variation in characteristics and high durability, it can be used for plastic IC cards, information tags, displays, and the like.

It is a typical schematic sectional drawing which shows a part of one embodiment of the field effect transistor of this invention.

Explanation of symbols

1 Gate electrode 2 Insulating layer 3 A layer (layer containing polysiloxane compound or crystallization promoting layer)
4 Source electrode 5 Drain electrode 6 B layer (organic semiconductor layer)

Claims (24)

  In a method for manufacturing a semiconductor device having an organic semiconductor layer, a step of providing a crystallization promoting layer on a substrate, a step of applying an organic semiconductor precursor on the crystallization promoting layer, and light energy on the organic semiconductor precursor And a step of forming a layer made of an organic semiconductor by simultaneously applying heat energy and thermal energy.   2. The method of manufacturing a semiconductor element according to claim 1, wherein the thermal energy is applied by heating the base from outside.   The method for manufacturing a semiconductor element according to claim 1, wherein the crystallization promoting layer has a function of promoting bonding between crystal grains.   2. The step of forming a layer made of an organic semiconductor by simultaneously applying light energy and thermal energy to the organic semiconductor precursor includes a step of causing a desorption reaction in the organic semiconductor precursor. 4. A method for manufacturing a semiconductor device according to any one of claims 1 to 3.   The method of manufacturing a semiconductor device according to claim 4, wherein a reverse Diels-Alder reaction is used as the elimination reaction.   The step of applying an organic semiconductor precursor on the crystallization promoting layer is a step of applying or printing a solution containing the organic semiconductor precursor on the crystallization promoting layer. A method for manufacturing a semiconductor device according to any one of 1 to 5.   The method for manufacturing a semiconductor element according to claim 1, wherein a layer containing a polysiloxane compound is provided as the crystallization promoting layer. The method for manufacturing a semiconductor device according to claim 7, wherein a compound having at least a structure represented by the following general formula (1) is used as at least one of the polysiloxane compounds.

(In the formula, R ₁ to R ₄ are a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an alkenyl group, .R ₁ to R ₄ is either a substituted or unsubstituted phenyl group, or a siloxane unit Each may be the same or different, and n is an integer of 1 or more.) The semiconductor according to claim 7 or 8, wherein a polysiloxane compound having at least a structure represented by the following general formula (2) or the following general formula (3) is used as at least one of the polysiloxane compounds. Device manufacturing method.

(Wherein R _{5 to} R ₈ are any of a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an alkenyl group, and a substituted or unsubstituted phenyl group. Each of R _{5 to} R ₈ is (M and n are integers of 0 or more, and the sum of m and n is an integer of 1 or more.)

(Wherein R _{9 to} R ₁₂ are each a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an alkenyl group, or a substituted or unsubstituted phenyl group. Each of R _{9 to} R ₁₂ May be the same or different, r and p are integers of 0 or more, and the sum of r and p is an integer of 1 or more.) The compound having at least one selected from the bicyclo structure represented by the following general formulas (4) and (5) as a partial structure in the molecule is used as the organic semiconductor precursor. Item 10. A method for manufacturing a semiconductor device according to any one of Items 1 to 9.

(In the formula, R ₁₃ and R ₁₄ each independently represents an oxygen atom, a sulfur atom, or NR ₁₅ , where R ₁₅ is a linear or branched alkyl group having 1 to 12 carbon atoms, an alkenyl group. , An alkoxy group, an alkylthio group, an alkyl ester group, an aryl group, and a hydroxyl group.

(In the formula, R ₁₆ represents an oxygen atom or a sulfur atom.) The method for producing a semiconductor element according to claim 10, wherein a compound represented by the following general formula (6) is used as the organic semiconductor precursor.

(In the formula, the A ring represents any of the bicyclo rings represented by the general formula (4) or (5). R ₁₇ and R ₁₈ represent a hydrogen atom, an alkyl group, an alkoxy group, an ester group, or a phenyl group. R ₁₉ to R _{26 each} represents a hydrogen atom, alkyl group, alkoxy group, aryl group, heterocyclic group, aralkyl group, phenoxy group, cyano group, nitro group, ester group, carboxyl group or halogen atom R ₁₇ , R ₁₈ R ₁₉ to R ₂₆ may be the same as or different from each other, and R ₂₀ and R ₂₁ , R ₂₄ and R ₂₅ are connected to each other to form an A ring or a 5- or 6-membered heterocyclic ring. T, u, and v are integers greater than or equal to 0. The sum of t to v is an integer greater than or equal to 1.) 12. The compound according to claim 11, wherein the compound represented by the general formula (6) is a compound in which the A ring is represented by the general formula (4) and R ₁₃ and R ₁₄ are oxygen atoms. A method for manufacturing a semiconductor device.   12. The method of manufacturing a semiconductor device according to claim 1, wherein a field effect transistor is manufactured as the semiconductor device.   In the method for producing a field effect transistor having an organic semiconductor layer, a step of providing a layer containing a polysiloxane compound on a substrate, and a step of applying an organic semiconductor precursor on the layer containing the polysiloxane compound; And a step of simultaneously applying light energy and heat energy to the organic semiconductor precursor to form a layer made of an organic semiconductor. The method for manufacturing a semiconductor device according to claim 14, wherein a compound having at least a structure represented by the following general formula (1) is used as at least one of the polysiloxane compounds.

(In the formula, R _{1 to} R ₄ are any of substituted or unsubstituted alkyl groups having 1 to 8 carbon atoms, alkenyl groups, substituted or unsubstituted phenyl groups, or siloxane units. R _{1 to} R ₄ Each may be the same or different, and n is an integer of 1 or more.) 16. The semiconductor according to claim 14, wherein a polysiloxane compound having at least a structure represented by the following general formula (2) or the following general formula (3) is used as at least one of the polysiloxane compounds. Device manufacturing method.

(Wherein R _{5 to} R ₈ are any of a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an alkenyl group, and a substituted or unsubstituted phenyl group. Each of R _{5 to} R ₈ is (M and n are integers of 0 or more, and the sum of m and n is an integer of 1 or more.)

(Wherein R _{9 to} R ₁₂ are each a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an alkenyl group, or a substituted or unsubstituted phenyl group. Each of R _{9 to} R ₁₂ May be the same or different, r and p are integers of 0 or more, and the sum of r and p is an integer of 1 or more.) The compound having at least one selected from the bicyclo structure represented by the following general formulas (4) and (5) as a partial structure in the molecule is used as the organic semiconductor precursor. Item 17. A method for manufacturing a semiconductor device according to any one of Items 14 to 16.

(In the formula, R ₁₃ and R ₁₄ each independently represents an oxygen atom, a sulfur atom, or NR ₁₅ , where R ₁₅ is a linear or branched alkyl group having 1 to 12 carbon atoms, an alkenyl group. , An alkoxy group, an alkylthio group, an alkyl ester group, an aryl group, and a hydroxyl group.

(In the formula, R ₁₆ represents an oxygen atom or a sulfur atom.) The method for producing a semiconductor element according to claim 17, wherein a compound represented by the following general formula (6) is used as the organic semiconductor precursor.

(In the formula, the A ring represents any of the bicyclo rings represented by the general formula (4) or (5). R ₁₇ and R ₁₈ represent a hydrogen atom, an alkyl group, an alkoxy group, an ester group, or a phenyl group. R ₁₉ to R _{26 each} represents a hydrogen atom, alkyl group, alkoxy group, aryl group, heterocyclic group, aralkyl group, phenoxy group, cyano group, nitro group, ester group, carboxyl group or halogen atom R ₁₇ , R ₁₈ R ₁₉ to R ₂₆ may be the same as or different from each other, and R ₂₀ and R ₂₁ , R ₂₄ and R ₂₅ are connected to each other to form an A ring or a 5- or 6-membered heterocyclic ring. T, u, and v are integers greater than or equal to 0. The sum of t to v is an integer greater than or equal to 1.) The compound represented by the general formula (6) is a compound in which the A ring is represented by the general formula (4) and R ₁₃ and R ₁₄ are oxygen atoms. A method for manufacturing a semiconductor device.   20. The method of manufacturing a semiconductor element according to claim 14, wherein the thermal energy is applied by heating the base from outside.   15. The step of forming a layer made of an organic semiconductor by simultaneously applying light energy and thermal energy to the organic semiconductor precursor includes a step of causing a desorption reaction in the organic semiconductor precursor. The manufacturing method of the semiconductor element in any one of thru | or 20.   The method of manufacturing a semiconductor device according to claim 21, wherein a reverse Diels-Alder reaction is used as the elimination reaction.   The step of providing the organic semiconductor precursor on the layer containing the polysiloxane compound is a step of applying or printing a solution containing the organic semiconductor precursor on the layer containing the polysiloxane compound. The method for manufacturing a semiconductor device according to claim 14, wherein:   24. The method of manufacturing a semiconductor element according to claim 14, wherein a field effect transistor is manufactured as the semiconductor element.

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