JP2006080207A - Organic fet and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic FET which employs a charge-transfer complex which flows in a direction perpendicular to the surface as an interfacial layer of a thin film. <P>SOLUTION: The organic FET comprises a gate electrode 1, drain electrode 7, source electrode 8, active layer 3 formed of an organic semiconductor, and gate insulation film 2. In cross-sectional view, the interfacial layer 4 is interposed between the active layer 3 and the drain electrode 7 and between the active layer 3 and the source electrode 8. The interfacial layer 4 consists of acceptor atom regions 5 and donor atom regions 6. At least one electrode (7 and 8) selected among a group of drain electrode 7 and source electrode 8 is in contact with the acceptor atom regions 5 and the donor atom regions 6. The donor atom regions 6 and the acceptor atom regions 5 are in contact with each other, and the acceptor atom regions 5 and the donor atom regions 6 are in contact with the active layer 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an organic FET and a method for manufacturing the same, and more particularly, by bringing a contact surface between a donor molecular layer and an acceptor molecular layer into contact with a drain, a source electrode, and an active layer, so The present invention relates to an organic FET capable of improving carrier injection and a method for manufacturing the same.

  In recent years, research and development of devices using organic semiconductors have been actively conducted. Among them, organic electroluminescence (EL) is being put into practical use for display devices. An organic field effect transistor (FET) using an organic semiconductor as an active layer is also attracting attention as a switching element. Devices using these organic semiconductors have the advantages of a low-temperature process and low cost because the organic semiconductor can be produced by a printing method. In addition, since the device can be manufactured on a flexible substrate such as a plastic, there is mechanical flexibility. Utilizing these features, applications different from conventional devices using inorganic semiconductors are expected.

  Similar to inorganic semiconductors, organic FETs have a configuration including three electrodes, a gate, a source, and a drain. The current flowing between the drain and source electrodes is controlled by the voltage applied to the gate electrode. However, since the organic semiconductor has lower conductivity than the inorganic semiconductor, there are few carriers induced in the active layer of the organic FET. In order to form the channel of the active layer, carrier injection from the drain and source electrodes is required.

  In order to improve carrier injection from the drain electrode or the source electrode, an organic FET in which an interface layer is inserted between the active layer and the drain electrode or the source electrode has been proposed (see Non-Patent Document 1). FIG. 8 shows a cross-sectional view of an organic FET in which an interface layer of a conventional example described in Non-Patent Document 1 is inserted.

  First, a method for manufacturing an organic FET in which an interface layer of a conventional example is inserted will be described with reference to FIG. Al which is the gate electrode 102 is formed on the glass substrate 101 by vapor deposition, and polymethyl methacrylate (PMMA) which is the gate insulating film 103 is laminated by spin coating. On top of that, an organic semiconductor oligothiophene which is the active layer 104 is laminated by vacuum deposition. Thereafter, through the shadow mask, tetracyanoquinodimethane (TCNQ) as the interface layer 105, Au as the drain electrode 106 and the source electrode 107 are formed by vapor deposition.

  Next, the effect of the interface layer 105 will be described with reference to FIG. The oligothiophene that is the active layer 104 is a p-type semiconductor, and the carriers that flow through the channels in the active layer 104 are holes. For the interface layer 105, an acceptor molecule TCNQ which is an electron acceptor is used.

  The drain electrode 106 or the source electrode 107, the acceptor molecular layer which is the interface layer 105, and the p-type semiconductor layer which is the active layer 104 are configured as shown in FIG. The band diagram at this time is as shown in FIG. The acceptor molecular layer is treated as an insulator. In addition, there is a forbidden band between the conduction band and the valence band of the p-type organic semiconductor layer. At this time, a barrier of holes which are carriers from the metal Fermi level to the valence band of the p-type organic semiconductor layer is generated.

  However, since holes are injected from the acceptor molecular layer into the p-type organic semiconductor layer, holes are accumulated in the p-type organic semiconductor near the interface between the acceptor molecular layer and the p-type organic semiconductor layer. As a result, the valence band is bent. At this time, a band diagram as shown in FIG. Therefore, there is almost no barrier for holes which are carriers from the metal Fermi level to the p-type organic semiconductor layer.

  From the above, by inserting the interface layer 105, the injection of holes as carriers from the drain electrode 106 or the source electrode 107 to the active layer 104 is improved, and the drain-source current increases.

  However, since TCNQ used for the interface layer 105 has a conductivity close to that of an insulator, current does not flow so much.

  A charge transfer complex is mentioned as a thin film which has metallic conductivity. This is composed of a donor molecule and an acceptor molecule. When electrons move from the donor molecule to the acceptor molecule, a phase transition occurs, a charge transfer complex is formed, and the conductivity changes from insulating to metallic. A conductive thin film having this charge transfer complex has been proposed (see Patent Document 1). FIG. 9 is a cross-sectional view of a conductive thin film having the charge transfer complex of the conventional example described in Patent Document 1.

The manufacturing method of the electroconductive thin film which has a charge transfer complex of a prior art example is demonstrated using FIG. The donor molecule layer 112 is laminated on the substrate 111, and then the acceptor molecule layer 113 is laminated. The donor molecular layer 112 and the acceptor molecular layer 113 are alternately stacked. Since electrons move near the contact surface between the donor molecular layer 112 and the acceptor molecular layer 113 and a charge transfer complex is formed, a current easily flows in a direction parallel to the surface.
Adv. Mater. 1997, 9, no. 5, p389 Japanese Patent Publication No. 7-19925 (page 2-3) JP 2002-299582 A (particularly FIGS. 2 and 22) Japanese Patent Laid-Open No. 9-2466426 (particularly FIG. 1)

  However, in Non-Patent Document 1 cited as an example of the prior art, since the TCNQ used for the interface layer has a conductivity close to that of an insulator, current hardly flows. In addition, the effect is effective only when the active layer is a p-type semiconductor, and the n-type semiconductor has a problem that it is necessary to prepare another interface layer.

  In Patent Document 1 cited as an example of the prior art, a conductive thin film having a charge transfer complex has a problem that current does not flow in a direction perpendicular to the surface. Therefore, even if the conductive thin film having this charge transfer complex is applied to the interface layer as it is, it does not contribute to carrier injection from the drain electrode or the source electrode.

  The present invention solves the above-described conventional problems, and an object thereof is to provide an organic FET in which a thin film having a charge transfer complex flowing in a direction perpendicular to the surface is applied to an interface layer.

The present invention for solving this problem is an organic FET including a gate electrode, a drain electrode, a source electrode, an active layer formed of an organic semiconductor, and a gate insulating film.
An interface layer is inserted between the active layer and the drain electrode and the source electrode,
The interfacial layer is composed of an acceptor molecule region and a donor molecule region,
At least one electrode selected from the group consisting of a drain electrode or a source electrode is in contact with the region of the acceptor molecule;
The electrode is in contact with the region of the donor molecule;
The region of the donor molecule and the region of the acceptor molecule are in contact with each other,
The acceptor molecule region is in contact with the active layer,
The region of the donor molecule is in contact with the active layer.

  The angle formed by the fifth interface and the third interface is preferably in the range of 80 to 100 degrees.

  In such an organic FET, the interface layer is preferably formed by a step of forming a recess in a layer made of donor molecules and a step of filling the recess with an acceptor molecule. Or it is preferable to form through the process of forming a hole in the layer which consists of acceptor molecules, and the process of filling this hole with a donor molecule.

  More specifically, such an organic FET includes a step of forming a gate electrode on a substrate, a step of forming a gate insulating film on the gate electrode, a step of forming an active layer on the gate insulating film, And a step of forming a drain electrode and a source electrode on the interface layer.

  The holes are formed by means of transferring a pattern with a mold, and it is preferable to fill the holes with acceptor molecules (or donor molecules) by an ink jet printing method using a solution containing acceptor molecules (or donor molecules). It is preferable to evaporate the solvent after filling. The surface of the mold is preferably hydrophilic.

  According to the organic FET of the present invention, carrier injection from the drain or source electrode to the active layer can be improved regardless of the type of the active layer.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1A is a cross-sectional view of the organic FET of this embodiment. 1 is a gate electrode, 2 is a gate insulating film, 3 is an active layer, 4 is an interface layer, 5 is an acceptor molecule region, 6 is a donor molecule region, 7 is a drain electrode, 8 is a source electrode, and 9 is a substrate. .

  In the present embodiment, as an example, a Si substrate is used as the substrate 9. A gate electrode 1 is formed by doping a p-type impurity into a Si substrate, and a gate insulating film 2 is formed by oxidizing the surface of the Si substrate.

  An active layer 3 is formed on the gate insulating film 2 by vapor-depositing pentacene, which is a p-type organic semiconductor, and an interface layer 4 is formed thereon. The interface layer 4 will be described in detail later together with its formation method.

  A metal (for example, Au) is formed on the drain electrode 7 and the source electrode 8 on the interface layer 4 by vacuum deposition. Holes as carriers are injected from the source electrode 8 into the active layer 3 as shown by arrows in FIG. 1, and a channel layer is formed in the vicinity of the gate insulating film 2. The drain electrode 7 is reached through the channel layer.

  The interface layer 4 includes an acceptor molecule region 5 and a donor molecule region 6, and is inserted between the drain electrode 7 and the source electrode 8 and the active layer 3. In this embodiment, as an example, TCNQ is used as an acceptor molecule, and tetrathiafulvalene (TTF) is used as a donor molecule.

  FIG. 1B is an enlarged cross-sectional view of a cross section near the interface layer 4. In this figure, the electrode is a drain electrode. In this figure, the following five interfaces are formed.

That is,
A first interface 31, which is an interface between the drain electrode 7 and the acceptor molecule 5 region, formed by contacting the drain electrode 7 and the acceptor molecule 5 region;
A first interface 32, which is an interface between the drain electrode 7 and the donor molecule 6 region formed by contacting the drain electrode 7 and the donor molecule 6 region;
A third interface 33, which is an interface between the acceptor molecule region 5 and the donor molecule region 6, formed by contacting the acceptor molecule region 5 and the donor molecule region 6;
A fourth interface 34, which is an interface between the active layer 3 and the acceptor molecule 5 region, formed by the contact between the active layer 3 and the acceptor molecule 5 region, and the active layer 3 and the donor molecule 6 A fifth interface 35, which is an interface between the active layer 3 and the region of the donor molecule 6 formed by being in contact with the region of

  In the vicinity of the third interface 33, electrons move from the donor molecule region 6 to the acceptor molecule region 5, and a charge transfer complex is formed in the vicinity of the third interface 33.

  This charge transfer complex makes it possible to improve carrier injection from the drain electrode 7 to the active layer 3. The angle θ (see FIG. 1B) formed by the fifth interface 35 and the third interface 33 is preferably between 80 and 100 °. More preferably, it is 90 °.

  FIG. 2 is a view of the organic FET of this embodiment as viewed from above. As can be seen from FIG. 2, in this embodiment, as an example, a recess is formed in the donor molecule region 6, and the acceptor molecule region 5 is filled in the recess.

  A drain electrode 7 and a source electrode 8 are formed on the interface layer 4 thus formed.

  If the area of the recesses is smaller than the area of the drain electrode 7 and the source electrode 8 and the density of the recesses is increased, the drain electrode 7 and the source electrode 8 are brought into contact with the charge transfer complex formed in the interface layer 4. be able to.

  In this embodiment, the channel length L is 5 μm, the channel width W is 20 μm, the electrode width W is 3 μm, the diameter d1 of the recesses is 100 nm, and the interval d2 of the recesses is 100 nm.

At this time, since the number density of the concave portions is 25 / μm ² , the drain electrode 7 and the source electrode 8 are in contact with about 3000 concave portions, respectively. That is, one drain electrode 7 and one source electrode 8 are in contact with a plurality of third interfaces 33.

  Next, it will be described with reference to FIGS. 3 and 4 that the carrier injection is improved by inserting the interface layer 4 between the drain electrode 7 and the source electrode 8 and the active layer 3. FIG. 3 shows a case where the active layer is an n-type organic semiconductor layer, and FIG. 4 shows a case where the active layer is a p-type organic semiconductor layer.

  FIG. 3A shows a structure of a metal-donor molecule layer-n-type organic semiconductor layer. The band diagram at this time is as shown in FIG. The donor molecular layer is treated as an insulator. In addition, there is a forbidden band between the conduction band and the valence band of the n-type organic semiconductor. At this time, a barrier of electrons which are carriers from the Fermi level of the metal to the n-type organic semiconductor layer is generated. However, since electrons are injected from the donor molecular layer into the n-type organic semiconductor layer, electrons are accumulated in the n-type organic semiconductor near the interface between the acceptor molecular layer and the n-type organic semiconductor layer. This bends the conduction band. At this time, a band diagram as shown in FIG. Therefore, there is almost no barrier for electrons that are carriers from the Fermi level of the metal to the n-type organic semiconductor layer.

  FIG. 4A shows a configuration of a metal-acceptor molecular layer-p-type organic semiconductor layer. The band diagram at this time is as shown in FIG. The acceptor molecular layer is treated as an insulator. In addition, there is a forbidden band between the conduction band and the valence band of the p-type organic semiconductor layer. For this reason, the barrier of the hole which is a carrier from the Fermi level of a metal to the valence band of a p-type organic-semiconductor layer arises. However, since holes are injected from the acceptor molecular layer into the p-type organic semiconductor layer, holes are accumulated in the p-type organic semiconductor near the interface between the acceptor molecular layer and the p-type organic semiconductor layer. As a result, the valence band is bent. At this time, a band diagram as shown in FIG. Therefore, there is almost no barrier for holes that are carriers from the Fermi level of the metal to the p-type organic semiconductor layer.

  Thus, when the active layer is an n-type organic semiconductor, the active layer is a p-type organic semiconductor, and in any case, the barrier for carrier injection is almost eliminated due to the effect of the donor molecular layer or the acceptor molecular layer. To improve the carrier injection to the organic semiconductor layer.

  However, as described above, since both the donor molecular layer and the acceptor molecular layer are insulators, the conductivity is low, and carrier injection from the metal into the organic semiconductor layer is limited. However, since the charge transfer complex is formed in the vicinity of the third interface 33, the conductivity is high and the metal is made more so that the carrier injection from the drain and source electrodes to the active layer is not limited. Be improved.

  As described above, in the interface layer 4 of the present invention, since the donor molecule region 6 and the acceptor molecule region 5 are both in contact with the active layer 3, the active layer 3 is a p-type or n-type organic semiconductor. Regardless, the barrier for carrier injection from the drain electrode 7 and the source electrode 8 to the active layer 3 can be reduced.

  Further, the donor molecule region 6 and the acceptor molecule region 5 constituting the interface layer 4 of the present invention are in contact with each other through the third interface 33, and the donor molecule region 6 and the acceptor molecule region 5 are respectively It is in contact with the drain electrode 7 (or the source electrode 8) through the first interface 31 and the second interface 32, and is in contact with the active layer 3 through the fourth interface 34 and the fifth interface 35. Thus, carrier injection from the drain electrode 7 and the source electrode 8 to the active layer 3 can be further improved by the charge transfer complex formed in the vicinity of the third interface 33.

<Manufacturing method>
First, a manufacturing method at a stage until the active layer 3 is formed will be described.

A Si substrate was used as the substrate 9. The gate electrode 1 is formed by doping a p-type impurity such as boron (B) on the surface. By oxidizing the surface of the substrate, SiO ₂ is formed and used as the gate insulating film 2. By using vacuum deposition, pentacene was formed on the gate insulating film 2 made of SiO ₂ as the active layer 3 of the p-type organic semiconductor.

  Next, a method for manufacturing the interface layer 4 will be described with reference to FIGS.

  A process for forming a recess in the donor molecule region will be described. Here, nanoimprint lithography is used.

  FIG. 5 is a diagram illustrating a process of forming a recess in the donor molecular layer 10. FIG. 6 is a view showing the mold 14 necessary for forming the recess.

(1) First, description will be made with reference to FIG. By oxidizing the surface of the Si substrate which is the transfer substrate 11, SiO ₂ which is the transfer substrate surface 12 is formed. A donor molecule layer 10 is formed by depositing TTF, which is a donor molecule, about 15 nm on the substrate by vapor deposition. FIG. 6 is a view for explaining the mold 15. 6A is a cross-sectional view of the mold, and FIG. 6B is a view of the mold as viewed from above. By oxidizing the surface of the Si substrate which is the mold substrate 14, SiO ₂ is formed on the mold surface 13, patterned by lithography, and etched to form the mold 15. A black circle portion in FIG. 6B is a convex portion. The convex portions are arranged on the surface at regular intervals. In this embodiment, the diameter of the convex portions is 90 nm, the interval between the convex portions is 110 nm, and the height of the convex portions is 10 nm.

  (2) Next, a description will be given with reference to FIG. The Si substrate 11 is heated so that the melting point of the TTF that is the donor molecular layer 10 is 114 ° C. In a state where the donor molecular layer 10 is softened by heating, the mold 15 is brought into contact with the donor molecular layer 10 and pressed to deform the donor molecular layer 10. While maintaining the pressed state, the substrate temperature is cooled to cure the donor molecule layer 10, and the uneven pattern of the mold 15 is transferred to the donor molecule layer 10.

(3) Next, refer to FIG. The substrate temperature is gradually cooled, and the mold 15 is released when the donor molecular layer 10 is sufficiently cured. At this time, a portion corresponding to the convex portion of the mold 14 remains on the SiO ₂ as a thin residual film of about 5 nm.

  (4) Finally, refer to FIG. The remaining film of the donor molecular layer 10 is removed by oxygen reactive ion etching (RIE) or the like to expose the silicon surface.

  By doing so, the concave / convex pattern of the mold can be transferred to the donor molecular layer, and concave portions arranged at regular intervals can be formed on the surface of the donor molecular layer.

  Next, a method for injecting acceptor molecules into the recesses formed in the donor molecule region will be described. Here, an inkjet printing method is used.

  The donor molecule region 6 was patterned by the nanoimprinting lithography described above. FIG. 7A is a cross-sectional view of a substrate on which a donor molecule region is patterned, and FIG. 7B is a view of the substrate as viewed from above.

  As can be seen from FIG. 7B, the recesses are arranged at regular intervals on the surface. An appropriate amount of an acceptor molecule solution is injected into the recess using an inkjet printing method. As shown in FIG. 7A, the inkjet head 22 is moved to the center of each recess in the donor molecule region 6. The ink jet apparatus used in this embodiment is provided with an optical detector, and an alignment mark is previously attached to the end of the donor region film. The position of the concave portion can be specified with reference to the alignment mark. Since the recesses are arranged at regular intervals on the surface, it is possible to cover all the recesses by moving a certain distance in the vertical and horizontal directions.

  In this embodiment, as an example, TCNQ is used as an acceptor molecule, and chloroform is used as a solvent.

As described above, after the acceptor molecule solution is injected into the concave portion of the donor molecule region 6, annealing is performed at a boiling point of chloroform of 61 ° C. in an N ₂ atmosphere to evaporate the solvent.

  The interface layer 4 can be formed on the Si substrate 11 by the method as described above.

The formed interface layer 4 is bonded onto the substrate 9 on which the organic semiconductor active layer 3 produced by the process described above is formed. The transfer substrate surface 12 on which the interface layer 4 is formed is covered with hydrophilic SiO ₂ . Since the active layer 3 is an organic molecule, the active layer 3 has better adhesion to the acceptor molecule region 5 and the donor molecule region 6 than the transfer substrate surface 12. Therefore, the transfer substrate 11 and the transfer substrate surface 12 can be peeled off. By doing so, the interface layer 4 can be transferred onto the substrate 9.

  Thereafter, the drain electrode 7 and the source electrode 8 are formed by vapor-depositing a metal such as Au using a shadow mask, whereby the organic FET of this embodiment is manufactured.

  As described above, the organic FET according to the first embodiment of the present invention includes the donor molecule region 6 and the acceptor molecule region 5 between the drain electrode 7 and the source electrode 8 and the active layer 3. It becomes possible to insert the interface layer 4.

  In the conventional example, in the interface layer using the acceptor molecular layer which is an electron acceptor, the active layer is effective only for the p-type organic semiconductor. However, since both the donor molecule region 6 and the acceptor molecule region 5 are in contact with the active layer 3 in the interface layer 4 of the present invention, the active layer is not limited to the p-type or n-type organic semiconductor. The barrier of carrier injection from the electrode 7 and the source electrode 8 to the active layer 3 can be reduced.

  In the conventional example, the interface layer using the acceptor molecular layer which is an electron acceptor has an insulating conductivity and does not flow much current. However, in the present invention, the donor molecule region 6 and the acceptor molecule region 5 constituting the interface layer 4 are in contact with each other through the third interface 33, and the donor molecule region 6 and the acceptor molecule region 5 are They are in contact with the drain electrode 7 (or the source electrode 8) through the first interface 31 and the second interface 32, respectively, and are in contact with the active layer 3 through the fourth interface 34 and the fifth interface 35. Therefore, carrier injection from the drain electrode 7 and the source electrode 8 to the active layer 3 can be further improved by the charge transfer complex formed in the vicinity of the third interface 33.

  In the above embodiment, the interface layer 4 exists also between the drain electrode 7 and the source electrode 8, but the interface layer 4 that does not contribute to the flow of carriers is not necessarily required. That is, the active layer 3 may be exposed between the drain electrode 7 and the source electrode 8.

  Further, both the drain electrode 7 and the source electrode 8 are in contact with the acceptor molecule region 5 and the donor molecule region 6, respectively, but the carriers pass through the active layer 3 between the source electrode 8 and the drain electrode 7. As long as it flows through, only one of them may have a structure as shown in FIG. Considering such carrier flow, it is preferable that both the drain electrode 7 and the source electrode 8 have a structure as shown in FIG.

  Further, the third interface 33 formed when the acceptor molecule region 5 and the donor molecule region 6 are in contact with each other suffices to be provided in one place on the drain electrode 7 (the source electrode 8 is also the same), but FIG. ), It is preferable that a plurality of third interfaces 33 exist with respect to the drain electrode 7 (the same applies to the source electrode 8).

  The organic FET according to the present invention is useful as a low voltage driving device or the like. It can also be applied to the use of a wireless ID tag.

(A) Sectional view of the organic FET according to the first embodiment of the present invention (B) Enlarged view of the section of the organic FET according to the first embodiment of the present invention with the interface layer added The figure which looked at organic FET of Embodiment 1 of this invention from the top Diagram explaining carrier injection of metal-donor molecular layer-n-type organic semiconductor layer Diagram explaining carrier injection of metal-acceptor molecular layer-p-type organic semiconductor layer Diagram showing interface layer fabrication method using nanoimprinting lithography (A) Cross section of mold shape (B) View from above of mold shape The figure which showed the preparation method of the interface layer by the ink jet printing method Sectional view of an organic FET with an electron acceptor inserted in the electrode interface of the conventional example Sectional view of a conductive thin film having a conventional charge transfer complex

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gate electrode 2 Gate insulating film 3 Active layer 4 Interface layer 5 Acceptor molecule area 6 Donor molecule area 7 Drain electrode 8 Source electrode 9 Substrate 10 Donor molecular layer 11 Transfer substrate (Si)
12 Transfer substrate surface (SiO ₂ )
13 Mold surface (SiO ₂ )
14 Mold substrate (Si)
15 Mold 21 Acceptor Molecule Solution 22 Inkjet Head 32 Second Interface 33 Third Interface 34 Fourth Interface 101 Substrate 102 Gate Electrode 103 Gate Insulating Film 104 Active Layer 105 Interface Layer 106 Drain Electrode 107 Source Electrode 111 Substrate 112 Donor Molecular layer 113 Acceptor molecular layer

Claims (12)

An organic FET including a gate electrode, a drain electrode, a source electrode, an active layer formed of an organic semiconductor, and a gate insulating film.
An interface layer is inserted between the active layer and the drain electrode and the source electrode,
The interfacial layer is composed of an acceptor molecule region and a donor molecule region,
At least one electrode selected from the group consisting of a drain electrode or a source electrode is in contact with the region of the acceptor molecule;
The electrode is in contact with the region of the donor molecule;
The region of the donor molecule and the region of the acceptor molecule are in contact with each other,
The acceptor molecule region is in contact with the active layer,
An organic FET in which the donor molecule region is in contact with the active layer. 2. The organic FET according to claim 1, wherein an angle formed by the fifth interface and the third interface is in a range of 80 degrees to 100 degrees. A method for producing an organic FET according to claim 1,
The interface layer is
A method for producing an organic FET, comprising: forming a recess in a layer made of donor molecules; and filling the recess with an acceptor molecule. A method for producing an organic FET according to claim 1,
The interface layer is
An organic FET manufacturing method formed through a step of forming a hole in a layer made of an acceptor molecule, and a step of filling the hole with a donor molecule. Forming a gate electrode on the substrate;
Forming a gate insulating film on the gate electrode;
Forming an active layer on the gate insulating film;
Forming the interface layer on the active layer;
Forming a drain electrode and a source electrode on the interface layer;
The manufacturing method of the organic FET of Claim 3 which has these. Forming a gate electrode on the substrate;
Forming a gate insulating film on the gate electrode;
Forming an active layer on the gate insulating film;
Forming the interface layer on the active layer;
Forming a drain electrode and a source electrode on the interface layer;
The manufacturing method of the organic FET of Claim 4 which has these. The hole is formed by means for transferring a pattern by a mold,
The method for producing an organic FET according to claim 3, wherein the hole is filled with an acceptor molecule by an inkjet printing method with a solution containing the acceptor molecule. The hole is formed by means for transferring a pattern by a mold,
The method for producing an organic FET according to claim 4, wherein the hole is filled with donor molecules by a solution containing donor molecules by an inkjet printing method.   The method for producing an organic FET according to claim 7, wherein the solvent is evaporated after filling the holes with acceptor molecules.   The method for producing an organic FET according to claim 8, wherein the solvent is evaporated after filling the holes with donor molecules.   The method of manufacturing an organic FET according to claim 7, wherein a surface of the mold is hydrophilic. The method of manufacturing an organic FET according to claim 8, wherein a surface of the mold is hydrophilic.

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