JP5277532B2 - Electronic element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic element whose manufacturing cost is low and rapid response is good. <P>SOLUTION: An insulating layer 3 is formed in an upper surface 2a of a linear first electrode on a substrate 1. The insulating layer 3 is left without removing resist used for etching treatment for forming an electrode layer 2. An insulating layer 4 is formed from a side surface 2b of the electrode layer 2 through an upper surface of the insulating layer 3 over a side surface 2c of the electrode layer 2. A conductive layer 5 is formed on the insulating layer 4. An electrode layer 6 is formed adjacent to an insulation part B at the side surface 2b side of the electrode layer 2 in plane view. Similarly, an electrode layer 7 is formed in the side surface 2c side. A semiconductor layer 8 is formed in a region covering the insulation part B. Specific inductive capacity and film thickness of an insulation part A are set so that its electrostatic capacity is smaller than that in such a case that the insulation part A is constituted of an insulating layer having the same film thickness and the same specific inductive capacity as the insulation part B. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to an electronic device that can be manufactured at low cost and has high-speed response.

  Typical display devices used for information display and the like include a CRT (Cathode Ray Tube, hereinafter abbreviated as CRT) display, a liquid crystal display device, an EL (Electroluminescence, hereinafter abbreviated as EL) display device, and the like.

  Conventionally, CRT displays have been widely used as display devices because of their relatively low manufacturing costs and high display quality. However, it is difficult to reduce the thickness and power consumption of CRTs.

  Therefore, in recent years, the demand for liquid crystal display devices and EL display devices that are thin and consume relatively little power has increased rapidly.

  In recent years, the usefulness of IC (Integrated Circuit) (hereinafter abbreviated as IC) tags capable of reading / writing data without contact has been attracting attention. IC tags are expected to expand the market in the future because they can dramatically improve the efficiency of logistics and supply chain management of products and personal information. A number of arithmetic devices are incorporated in the IC tag.

  Field-effect transistors are used as the above-described display devices and IC tag arithmetic devices.

  A typical field effect transistor has a semiconductor material, a first electrode (gate electrode), a second electrode (source electrode), and a third electrode (drain electrode), and has a typical structure. There are a planar type (see FIG. 16A) and an inverted stagger type (see FIG. 16B).

  In recent years, organic semiconductor materials that can be manufactured by a coating process have been actively developed as low-cost semiconductor materials used for field-effect transistors and the like. If such an organic semiconductor material is used, a semiconductor device such as a transistor can be manufactured by a normal temperature coating process that does not require an expensive vacuum apparatus or the like, and thus manufacturing costs can be reduced (for example, Patent Documents). 1).

  There is a polythiophene material as an organic semiconductor material that can be applied to such a coating process and has a relatively high mobility (see, for example, Non-Patent Document 1).

Further, with the aim of improving high-speed response and high integration, an insulating layer is formed in a convex shape on the first electrode formed on the substrate, and the insulating layer on the top and both sides of the first electrode is sandwiched 3 A field effect transistor in which two electrodes are formed has also been proposed (see, for example, Patent Documents 2 and 3).
JP 2005-268607 A JP 2005-19446 A JP 2004-349292 A Applied Physics Letter, vol. 69. p4108 (1996)

  Since the conventional transistor is configured as described above, it has the following problems.

The mobility of the organic material applicable to the coating process is less than 0.1 cm ² / V · sec, which is almost an order of magnitude smaller than that of amorphous silicon.

  For this reason, in general, a transistor using an organic semiconductor material has a cut-off frequency that is an index of high-speed responsiveness on the order of KHz, and requires a cut-off frequency of several MHz or higher, and a high-definition video display device or IC tag. It cannot be used for.

  One technique for improving the cutoff frequency is to shorten the channel in the transistor in addition to increasing the mobility of the organic semiconductor material.

  However, generally, in order to pattern a source electrode and a drain electrode having a channel length of about 1 μm to 1 μm or less, a complicated process and an expensive manufacturing apparatus are required. For this reason, shortening the channel causes an increase in manufacturing cost.

  In order to improve the cutoff frequency, it is necessary to reduce the parasitic capacitance in the transistor.

  For example, in the planar type transistor shown in FIG. 16A and the inverted stagger type transistor shown in FIG. 16B, gate insulation is provided between the gate electrode and the source electrode and between the gate electrode and the drain electrode. Parasitic capacitance is formed to sandwich the film. The same applies to the transistor described in Patent Document 1.

  As described above, when the parasitic capacitance between the gate electrode and the source electrode and between the gate electrode and the drain electrode is large, a portion unrelated to the operation of the transistor is charged when a voltage is applied to the gate electrode. The high-speed response is reduced.

  Such a problem related to the parasitic capacitance is left unsolved even in the field effect transistors described in Patent Documents 2 and 3, and is particularly formed with a gate electrode and an insulating layer sandwiched between the gate electrode. In addition, the parasitic capacitance between the second electrode and the second electrode was large, and the high-speed response did not reach a sufficient level.

  Further, when a high frequency voltage is applied to the gate electrode, the impedance due to the parasitic capacitance becomes very small, so that the gate current flows to the source electrode and the drain electrode, resulting in an increase in power consumption. Such transistors are particularly difficult to apply to battery-powered applications such as mobile applications.

  For this reason, in a planar type or inverted stagger type transistor, it is necessary to align the gate electrode, the source electrode, and the drain electrode so that they hardly overlap each other. However, in particular, when the substrate is made of a material that easily contracts, such as a resin film, the alignment of the electrodes becomes more difficult as the area increases.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an electronic device with low manufacturing cost and good high-speed response.

An electronic device according to an aspect of the present invention is formed on a substrate and has a first electrode in a line shape having an upper surface, a first side surface, and a second side surface, and a film-shaped first electrode formed on the upper surface of the first electrode. An insulating part;
A film-like second insulating part formed on the first and second side surfaces of the first electrode adjacent to the first insulating part; a conductive layer formed on the upper surface of the first insulating part; A second electrode formed in a region on the substrate and adjacent to the second insulating portion on the first side surface in plan view; and a second electrode formed in a region on the substrate and on the second insulating portion on the second side surface side. A third electrode adjacent in plan view, a region covering the second insulating part between the conductive layer and the second electrode, and the second insulating part between the conductive layer and the third electrode. A semiconductor layer formed in a region to be covered, and the first insulating portion is formed from an insulating layer having the same film thickness and the same relative dielectric constant as the second insulating portion. is composed of an insulating layer, also capacitance having the film thickness and the dielectric constant decreases, the first insulating portion, forming the first electrode Composed of the resist layer having an insulating property used in that. Thereby, the parasitic capacitance in the element can be reduced.

According to another aspect of the present invention, there is provided an electronic device formed on a substrate and having a top surface, a first side surface having a first side surface and a second side surface, and a film shape formed on the top surface of the first electrode. A first insulating portion, a film-shaped second insulating portion formed on the first side surface and the second side surface of the first electrode adjacent to the first insulating portion, and a region on the substrate, A second electrode adjacent in plan view to the second insulating portion on the first side surface side, and a second electrode formed continuously over the region on the substrate from the upper surface of the first insulating portion through the second side surface side. Three electrodes, and a semiconductor layer formed in a region covering the second insulating portion between the second electrode and the third electrode, wherein the first insulating portion includes the first insulating portion. (2) A film thickness with a smaller capacitance than that of an insulating layer having the same film thickness and the same dielectric constant as the insulating part. Is composed of an insulating layer having a dielectric constant, the first insulating portion is composed of a resist layer having an insulating property which is used in forming the first electrode. Thereby, the parasitic capacitance in the element can be reduced.

  The insulating layer other than the resist layer may include an insulating layer formed integrally with the second insulating portion. Thereby, the film thickness of a 1st insulating part can be made thicker than a 2nd insulating part.

  The resist layer may have a semicircular cross-sectional shape or a trapezoid whose bottom is longer than the top. Thereby, the electrostatic capacitance of a 2nd insulation part can be reduced.

  Further, the first electrode may have a rectangular shape or a reverse tapered shape in cross section. Thereby, the distance between the 2nd electrode layer and the 3rd electrode layer can be shortened.

  According to the present invention, by using the organic semiconductor material and reducing the parasitic capacitance in the element, it is possible to provide a specific effect that it is possible to provide an electronic element that can be manufactured at a low cost and has a high speed response. .

  Hereinafter, exemplary embodiments of an electronic device to which the present invention is applied will be described.

Embodiment 1
<Configuration of electronic element>
FIG. 1A is a diagram schematically showing a cross-sectional structure of the electronic device according to the first embodiment, and FIG. 1B is a conceptual diagram showing an enlarged main part of the electronic device shown in FIG. A sectional view shown in FIG. 1C is a conceptual diagram for explaining a channel formed in an electronic element.

  As shown in FIG. 1A, the electronic device according to the first embodiment includes, for example, a linear electrode layer 2 (first electrode layer) on an insulating substrate 1 made of a glass plate or a resin film. ). The electrode layer 2 is an electrode layer having a uniform film quality formed of a single conductive material.

  An insulating layer 3 (first insulating layer) is formed on the upper surface 2 a of the electrode layer 2. The insulating layer 3 is formed by forming a material layer (not shown) for forming the electrode layer 2 on one surface of the substrate 1 and then removing the resist used in the etching process for forming the electrode layer 2. It is what was left behind. For this reason, the resist for forming the insulating layer 3 is an insulating material having a predetermined relative dielectric constant and needs to be formed so as to have a predetermined film thickness. The relative dielectric constant and film thickness of this resist will be described later.

  The insulating layer 3 can be made of an insulating resist material such as a positive resist TSMR8800 manufactured by Tokyo Ohka Kogyo Co., Ltd.

  An insulating layer 4 (second insulating layer) is formed from the side surface 2b (first side surface) of the line-shaped electrode layer 2 through the upper surface of the insulating layer 3 to the side surface 2c (second side surface) of the electrode layer 2. Yes.

This insulating layer 4 is made of, for example, an inorganic insulating material such as SiO ₂ , Ta ₂ O ₅ , Al ₂ O ₃ , polyimide, styrene resin, polyethylene resin, polypropylene, vinyl chloride resin, polyester alkyd resin, polyamide, polyurethane, Polycarbonate, polyarylate, polysulfone, diallyl phthalate resin, polyvinyl butyral resin, polyether resin, polyester resin, acrylic resin, silicone resin, epoxy resin, phenol resin, urea resin, melamine resin; fluorine-based resin such as PFA, PTFE, PVDF A parylene resin; a photocurable resin such as epoxy acrylate or urethane-acrylate; an organic insulating material such as a polysaccharide such as pullulan or cellulose and a derivative thereof;

  Here, as shown in FIG. 1B, for convenience of explanation, the insulating layer 3 and the portion of the insulating layer 4 formed on the upper surface of the insulating layer 3 (that is, the electrode layer 2 indicated by a broken line in the figure) The insulating portion combined with the portion having the same width is referred to as an insulating portion A1 (first insulating portion), and a portion of the insulating layer 4 formed on the side surface side (side surface 2b and side surface 2c) of the electrode layer 2 (A portion indicated by a one-dot chain line in the drawing) is referred to as an insulating portion B1 (second insulating portion).

  A conductive layer 5 is formed on the insulating layer 4.

  The electrode layer 6 (second electrode layer) is formed adjacent to the insulating portion B1 on the side surface 2b side of the electrode layer 2 in plan view, and the insulating portion B1 on the side surface 2c side of the electrode layer 2 is viewed in plan view. An electrode layer 7 (third electrode layer) is formed adjacently.

  The conductive layer 5, the electrode layer 6, and the electrode layer 7 can be formed by a single process by printing a conductive material as a coating liquid. The forming method will be described later.

In addition, these layers can be produced with the same material as the electrode layer 2, and the volume resistivity is usually 1 × 10 ⁻³ Ω · cm or less, and 1 × 10 ⁻⁶ Ω · cm or less. preferable.

  The electrode layer 2, the conductive layer 5, the electrode layer 6, and the electrode layer 7 of the present embodiment are, for example, silver (Ag), gold (Au), chromium (Cr), tantalum (Ta), titanium (Ti), copper (Cu), aluminum (Al), molybdenum (Mo), tungsten (W), nickel (Ni), palladium (Pd), platinum (Pt), tin (Sn) and other metals, alloys such as ITO and IZO, polyacetylene Conductive polymers, poly (p-phenylene) and derivatives thereof, polyphenylene conductive polymers such as polyphenylene vinylene and derivatives thereof, polypyrrole and derivatives thereof, polythiophene and derivatives thereof, and heterocyclic conductivity such as polyfuran and derivatives thereof Composed of at least one of conductive materials such as ionic conductive polymers such as conductive polymers, polyaniline and derivatives thereof It can be. These metals, alloys, and conductive polymers can be used in combination. Further, the conductive polymer may be used with a higher conductivity by doping with a dopant. As the dopant, it is preferable to use a compound having a low vapor pressure such as polysulfonic acid, polystyrene sulfonic acid, naphthalene sulfonic acid, and alkyl naphthalene sulfonic acid.

  A semiconductor layer 8 is formed in a region covering the insulating portion B1 between the conductive layer 5 and the electrode layer 6 and a region covering the insulating portion B between the conductive layer 5 and the electrode layer 7. As will be described in detail later, a transistor channel is formed in these two regions.

  Hereinafter, for convenience of explanation, as shown by a broken line in FIG. 1C, a channel formed between the conductive layer 5 and the electrode layer 6 is referred to as a channel 8a, and between the conductive layer 5 and the electrode layer 7, The formed channel is referred to as channel 8b.

  As shown in FIG. 1A, the semiconductor layer 8 includes a region covering the insulating part B1 between the conductive layer 5 and the electrode layer 6, and an insulating part B1 between the conductive layer 5 and the electrode layer 7. May be formed so as to cover the upper surface of the conductive layer 5, but it is not always necessary to cover the upper surface of the conductive layer 5. 5 and the electrode layer 6 and the electrode layer 7 may be connected to each other.

  The semiconductor layer 8 includes, for example, fluorene and derivatives thereof, fluorenone and derivatives thereof, poly (N-vinylcarbazole) derivatives, polyglutamic acid γ-carbazolylethyl derivatives, polyvinylphenanthrene derivatives, polysilane derivatives, oxazole derivatives, oxadiazoles. Derivatives, imidazole derivatives; arylamine derivatives such as monoarylamines and triarylamine derivatives; benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, styrylanthracene derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, indenone derivatives , Butadiene derivatives; pyrene derivatives such as pyrene-formaldehyde and polyvinylpyrene; α-phenylstilbene derivatives, bisstilbene derivatives, etc. Stilbene derivatives; enamine derivatives; thiophene derivatives such as polyalkylthiophenes; pentacene, tetracene, bisazo, trisazo dyes, polyazo dyes, triarylmethane dyes, thiazine dyes, oxazine dyes, xanthene dyes, cyanine dyes , Styryl dyes, pyrylium dyes, quinacridone dyes, indigo dyes, perylene dyes, polycyclic quinone dyes, bisbenzimidazole dyes, indanthrone dyes, squarylium dyes, anthraquinone dyes; copper phthalocyanine, Organic semiconductor materials such as phthalocyanine dyes such as titanyl phthalocyanine, inorganic semiconductor materials such as CdS, ZnO, PbTe, PbSnTe, InGaZnO, GaP, GaAlAs, GaN, polycrystalline silicon, amorphous silicon It can be composed of silicon semiconductor material. In particular, it is preferable to use amorphous silicon in order to reduce the cost other than materials that can be applied. Amorphous silicon is preferable from the viewpoint of durability and operational stability of the TFT.

  Here, the relative dielectric constant and film thickness of the insulating layer constituting the insulating portion A1 will be described.

  In order to improve the high-speed response as an electronic element, it is necessary to reduce the electrostatic capacity in the element. In particular, in order to reduce the parasitic capacitance of the insulating portion A1 between the electrode layer 2 and the conductive layer 5, the relative permittivity and film thickness of the insulating portion A1 are the same as those of the insulating portion B1. In addition, the capacitance is higher than that of an insulating layer having the same relative dielectric constant (that is, the insulating portion A1 is formed of an insulating layer having the same relative dielectric constant and the same film thickness as the insulating layer 4). It is necessary to set it to be smaller.

  Insulating part A1 of the present embodiment is a laminated body of insulating layer 3 and insulating layer 4. A part of the insulating layer 4 is integrally formed with the insulating layer constituting the insulating portion B1. For this reason, in order to reduce the parasitic capacitance of the insulating portion A1, the relative dielectric constant and film thickness of the insulating layer 3 are set in accordance with the ratio of the relative dielectric constant of the insulating layer 3 and the insulating layer 4 to the electrostatic capacitance of the insulating portion A1. The capacitance needs to be set smaller than “the capacitance of the insulating portion A1 when the insulating portion B1 is formed of an insulating layer having the same film thickness and the same relative dielectric constant”.

  For the same reason, the film thickness of the insulating layer 4 is preferably set so that the film thickness on the insulating part B1 side is equal to or smaller than the film thickness on the insulating part A1 side.

In such an electronic device, for example, when the semiconductor layer 8 is made of a p-type organic semiconductor material, a power source 9 for applying a negative bias to the gate electrode layer 2 is connected as shown in the figure, The electrode layer 6 is grounded, and a second power source 10 is connected between the electrode layer 6 and the electrode layer 7 to apply a voltage that makes the electrode layer 6 have a high potential. The operation principle of the electronic element connected to the power supply in this way will be described after the description of the manufacturing method.
<Method for manufacturing electronic device>
Next, the manufacturing method of the electronic element of this Embodiment is demonstrated using FIG.

  First, as shown in FIG. 2A, an electrode conductive layer 11 is formed on an insulating substrate 1 made of a glass plate or a resin film. The electrode conductive layer 11 is formed by using, as a coating liquid, a metal nanoparticle dispersion liquid containing a conductive material in which metal nanoparticles such as silver (Ag) and gold (Au) are dispersed in a solution. It is uniformly formed on the top. The formation process of the electrode conductive layer 11 is not limited to the printing process, and these conductive layer materials are formed by vapor deposition, sputtering, CVD (Chemical Vapor Deposition, hereinafter abbreviated as CVD), or the like. It may be a process to do.

  Next, as shown in FIG. 2B, a line-shaped resist layer 13 is formed in a region where the first electrode is to be formed on the electrode conductive layer 11. The planar dimension of the first electrode layer is defined by the planar dimension of the resist layer 13. The formation of the resist layer 13 can be performed, for example, by a microprinting method disclosed in Japanese Patent Laid-Open No. 2005-142175, Japanese Patent No. 3600546, or Japanese Patent Laid-Open No. 2006-140493.

  Here, the microprinting method will be described with reference to FIG.

  The electronic device in the manufacturing stage shown in FIG. 3A is an electronic device in the same manufacturing stage as that in FIG. 2A, and shows a stage in which the electrode conductive layer 11 is formed on the substrate 1.

  On this conductive layer 11 for electrodes, as shown in FIG.3 (b), the water-repellent pattern 12 is printed using the microprinting method. This water-repellent pattern 12 is printed in an area excluding a line-shaped area where the resist layer 13 is formed later. Note that the water-repellent processing is not performed on the line-shaped region for forming the resist layer 13. In general, a conductive material used for the electrode conductive layer 11 does not have water repellency, and therefore a resist used in this embodiment is selectively formed in a region where water repellent processing is not performed. This is because it can.

  Next, as shown in FIG. 3C, a resist layer 13 is printed in a linear region (a hydrophilic region) where a water-repellent pattern is not formed.

  In this way, the resist layer 13 can be formed on the electrode conductive layer 11.

  According to this microprinting method, it is possible to perform patterning with higher definition than the conventional printing method.

  When the resist layer 13 is formed, the electrode conductive layer 11 shown in FIG. 2B is etched to form the electrode layer 2 as shown in FIG. The resist layer 13 remains on the electrode layer 2, and in this embodiment, the resist layer 13 is used as the insulating layer 3 without being removed. The material for forming the insulating layer 3 (resist layer 13) is as described above.

  Subsequently, as illustrated in FIG. 2D, the insulating layer 4 is formed on the upper surface of the substrate 1, the side surfaces (side surfaces 2 b and 2 c) of the electrode layer 2, and the upper surface 2 a of the insulating layer 3.

  The electronic device shown in FIG. 1 has the insulating layer 4 only on the side surfaces (side surface 2b and side surface 2c) of the electrode layer 2 and the upper surface of the insulating layer 3, but the insulating layer 4 is formed as shown in FIG. The electrode layer 2 may be formed on the substrate 1 in the left and right regions.

  Further, as shown in FIG. 2E, a conductive layer 14 made of the same conductive film as the electrode conductive layer 11 is formed on the insulating layer 4.

  Here, a method for manufacturing the conductive layer 14 is described with reference to FIGS. For convenience of explanation, FIG. 4 is a perspective view showing the electronic element at the production stage from the side.

  4 (a) and 2 (d) show an electronic device in the same manufacturing stage.

  As shown in FIG. 4B, by rotating the printing plate 16 coated with the coating liquid 14a for forming the conductive layer 14 with the printing roller 15, as shown in FIG. A coating liquid 14 a is printed on the insulating layer 4. FIG. 2E shows the side surface of the electronic element at the stage where the printing process of the coating liquid 14 a is completed, and a small amount of the coating liquid 14 a is applied to both side surfaces of the insulating layer 4.

  As shown in FIG. 2 (e), the coating solution 14 a is lightly etched to remove the coating solution 14 a applied to both sides of the insulating layer 4. As a result, as shown in FIG. 2F, the conductive layer 5, the electrode layer 6, and the electrode layer 7 can be obtained from the coating liquid 14a.

  As a printing method for forming the conductive layer 5, the electrode layer 6 and the electrode layer 7 in this way, for example, a printing method using a relief plate such as a flexographic printing method, a printing method using a stencil such as a screen printing method, and offset printing. A printing method using a lithographic plate such as a printing method, a printing method using an intaglio plate such as a gravure printing method, or a printing method such as a spin coating method, a dipping method, a spray coating method, or an inkjet method can be used.

  In particular, in the present embodiment, the plate printing method represented by the flexographic printing method, the screen printing method, the offset printing method, or the gravure printing method is preferable because it is relatively easy to increase the area and improve the process tact. It is.

  In the present embodiment, the surface energy in the insulating portion B1 is sufficiently small, and it is desirable that the surface energy of the surface on which the conductive layer 5, the electrode layer 6 and the electrode layer 7 are formed be large. By setting the surface energy in this way, it is possible to suppress the conductive coating liquid 14a from adhering to the insulating portion B1.

  Channels (channel 8a and channel 8b) are formed in the semiconductor layer 8 formed in the insulating portion B1, and if a conductive film is formed in the channel, a malfunction may occur in the operation of the electronic element. There is. In order to prevent such a problem, it is necessary to prevent the formation of a conductive film on the insulating portion B1.

  Note that the state shown in FIG. 2 (e) does not occur when the surface energy of the insulating part B1 can be sufficiently reduced to prevent the coating liquid 14a from adhering to the insulating part B1. The etching treatment of the coating liquid 14a is not necessary.

  Finally, as shown in FIG. 2G, the semiconductor layer 8 is formed. As described above, in forming the semiconductor layer 8, it is necessary to connect between the conductive layer 5 and the electrode layer 6 and between the conductive layer 5 and the electrode layer 7.

Through the above manufacturing process, the electronic device of this embodiment can be manufactured.
<Operating Principle of Electronic Device>
When a negative voltage is applied to the electrode layer 2 by the power source 9, holes gather at the boundary between the conductive layer 5 and the electrode layer 6 and the insulating portion B1 in the semiconductor layer 8, and a hole channel is formed. This is the channel 8a described above.

  Similarly, holes gather at a boundary portion between the conductive layer 5 and the electrode layer 7 and the insulating portion B1 in the semiconductor layer 8 to form a hole channel. This is the channel 8b described above.

  Further, when the second power source 10 is turned on and a voltage is applied between the electrode layer 6 and the electrode layer 7 so that the electrode layer 7 is negative, holes are formed from the electrode layer 6 to the channel 8a, the conductive layer 5 and the channel 8b. And then flows to the electrode layer 7. That is, the electronic device of this embodiment is a field effect transistor in which the electrode layer 2 is a gate electrode, the electrode layer 6 is a source electrode, and the electrode layer 7 is a drain electrode.

  Since two channels are formed in this way, the equivalent circuit of the electronic element shown in FIG. 1A is a circuit in which two field effect transistors are connected as shown in FIG. A capacitance C represented in this equivalent circuit indicates a capacitance formed between the electrode layer 2 and the conductive layer 5. Further, as can be seen from this equivalent circuit, the conductive layer 5 apparently has a channel 8a side as a drain and a channel 8b side as a source.

<Dynamic characteristic evaluation>
The dynamic characteristics of the electronic device shown in FIG. 1 were evaluated under the following conditions.
(1) Configuration of electronic element Substrate: Glass Electrode layer 2: Aluminum (Al) (patterning to a width of 20 μm by wet etching)
Insulating layer 3: Positive resist TSMR8800 manufactured by Tokyo Ohka Kogyo Co., Ltd. (deposited to a film thickness of 250 nm by spin coating)
Insulating layer 4: Parylene C (registered trademark) (deposited to a film thickness of 230 nm by a CVD method)
Conductive layer 5, electrode layer 6 and electrode layer 7: made of gold (Au) (formed by vapor deposition)
Semiconductor layer 8: pentacene
Total channel length of channel 8a and channel 8b: 2.2 μm
(2) Configuration of Driving Device and Measuring Device As shown in FIG. 6, the first power supply 15 was connected to the electrode layer 2. The first power supply 15 is a function generator (FG) that generates a rectangular wave voltage of −9 to −10 (V). The electrode layer 6 was grounded. A second power source 17 was connected to the electrode layer 7 via a resistor 16. The second power supply 17 generates a reverse bias voltage of −15 (V). An oscilloscope (OS) 18 was connected between the electrode layer 7 and the resistor 16 in order to verify the cutoff frequency.
(3) Evaluation Using the drive device and the measurement device as described above, the cutoff frequency fc1 was obtained from the time Tr required for the output V (t) to rise or fall with the oscilloscope 18 as follows.

  Here, the time Tr is the longer of the time required for the rectangular wave to rise from 10% to 90% of the full scale and the time required for the square wave to fall from 90% to 10% of the full scale. Is used.

  Here, it can be expressed as V (t) = ± E (exp (−t / RC) −1). Here, E is a full-scale voltage value, R is a resistance value between the measurement system shown in FIG. 6 and the inside of the element, and C is a value of parasitic capacitance in the electronic element.

  Further, when the rise time is used as the time Tr, the time Tr is a time from an amplitude of 10% to 90%. Assuming that the time when V = 0.1E is t10 and the time when V = 0.9E is t90, the following equation holds, and t10 is obtained as shown in equation (1).

exp (−t10 / RC) = 1− (0.1E) / E
∴t10 = −RC · ln0.9 (1)
Similarly, t90 can be expressed as the following equation (2).

t90 = −RC · ln0.1 (2)
Since the time Tr is obtained as an elapsed time between the time t10 and the time t90, it is obtained from the equations (1) and (2) as the following equation (3).

Tr = t90−t10 = RC · (ln0.9−ln0.1) (3)
In general, relational expression (4) is established between fc1 and RC.

fc1 = 1 / (2πRC) (4)
From the expressions (3) and (4), the cutoff frequency fc1 can be expressed as the following expression (5).

Tr = (ln0.9−ln0.1) / (2πfc1) = (ln9) / (2πfc1)
∴fc1 = (ln9 / 2π) × 1 / Tr≈0.35 / Tr (5)
FIG. 7 shows the dynamic characteristics. From this characteristic, the rise time and fall time were obtained as follows.

Rise time: 0.252 μsec, fall time: 0.264 μsec
Thus, the time Tr = 0.264 μsec. By substituting this into equation (5), the cut-off frequency fc1 is obtained as follows.

∴fc1 = 0.35 / (0.264 × 10 ⁻⁶ ) ≈1.3 MHz
From the above, the cutoff frequency fc1 of the electronic element of the present embodiment was found to be 1.3 MHz.

  Here, for comparison, an electronic device obtained by removing the insulating layer 3 from the electronic device shown in FIG. 1A (actually, an electronic device manufactured by removing the resist 13 in the stage of FIG. 2C). The dynamic characteristics were evaluated under the same conditions.

  As a result, the rise time is 0.464 μsec and the fall time is 0.482 μsec. By substituting this into the equation (5), the cutoff frequency fc2 of the comparative electronic element can be obtained as follows.

fc2 = 0.35 / (0.482 × 10 ⁻⁶ ) = 0.72 MHz
Thus, in the comparative electronic element that does not include the insulating layer 3, the rise / fall time is significantly longer than that of the electronic element of the present embodiment, and the cutoff frequency is 0.72 MHz, which is a determination index for high-speed response. Below 1MHz. This is because the parasitic capacitance in the element is increased because the insulating layer 3 is not provided.

  According to the electronic device of the present embodiment, the insulating layer 3 is disposed on the electrode layer 2 to increase the thickness of the insulating portion A1, so that the static electricity between the electrode layer 2 and the conductive layer 5 can be reduced. Since the electric capacity is reduced, it is possible to obtain an electronic element having a high-speed response with a cut-off frequency of 1 MHz or more. This cut-off frequency is about twice the cut-off frequency of an electronic element that does not include the comparative insulating layer 3.

  Further, the insulating layer 3 provided in the electronic device of the present embodiment is used as it is without removing the resist for forming the electrode layer 2, and the manufacturing cost of the electronic device is reduced by simplifying the manufacturing process. Can also be planned.

  As described above, according to the electronic element of the present embodiment, by using the organic semiconductor material and reducing the parasitic capacitance in the element, it is possible to provide an electronic element that can be manufactured at low cost and has high-speed response. .

<Modification>
Although the cross-sectional shape of the insulating layer 3 used in the above description is rectangular, the cross-sectional shape of the insulating layer 3 is substantially semicircular as shown in FIG. 8A or shown in FIG. A trapezoidal shape with chamfered corners may be used.

  With such a shape, the amount of extension of the channel length C and the channel length D depending on the film thickness of the insulating layer 4 can be minimized as compared with the case where the cross-sectional shape of the electrode layer 2 is rectangular. These channel lengths C and D can be shortened.

  Thus, by reducing the distance between the conductive layer 5 and the electrode layer 6 and between the conductive layer 5 and the electrode layer 7, the resistance between the conductive layer 5 and the electrode layers 6 and 7 is reduced. The value can be reduced, and the electrostatic capacity of the channels 8a and 8b when the electrode layer 2 is used as a gate can be reduced, so that the cutoff frequency can be improved and further excellent high-speed response can be obtained. it can.

  In the electronic device described above, the electrode layer 2 is formed of a single conductive material. However, the composition ratio distribution of the conductive material is provided in the thickness direction of the electrode layer 2 using a plurality of types of conductive materials. It may be allowed.

  In general, when an electrode having a rectangular cross section is formed by etching, if the material distribution in the film thickness direction of the electrode is uniform, the etching progresses on both sides of the electrode is slower than the other regions, The cross-sectional shape may be a tapered shape (a trapezoid whose bottom is longer than the top).

  When the electrode layer 2 is formed, a conductive material including a plurality of metal materials having different etching rates is used so that the composition ratio of the conductive material having a high etching rate is increased on the substrate 1 side, and gradually toward the upper surface 2a. If the first electrode is formed so that the composition ratio of the conductive material having a low etching rate is increased, the tapered cross-sectional shape as described above can be corrected when the electrode layer 2 is formed by the etching process.

  For example, the electrode conductive layer 11 is adjusted while adjusting the composition ratio of the conductive material so that the lower side (substrate 1 side) of the electrode layer 2 is rich in chromium (Cr) and becomes rich in aluminum (Al) toward the upper side. Form. If a resist is formed on the upper surface of the electrode conductive layer 11 formed in this way and etched, the etching rate of chromium is faster than that of aluminum, so a rectangular cross-sectional shape as shown in FIG. An electrode layer 2 having a reverse tapered cross-sectional shape as shown in FIG. 9B can be formed.

  As described above, the electrode layer 2 having a rectangular or reverse tapered cross-sectional shape can be produced relatively easily. When the cross-sectional shape of the electrode layer 2 can be made rectangular or inversely tapered, as described above, when the conductive layer 14 is formed on the insulating layer 4, as shown in FIG. Since the conductive layer 14 is less likely to be formed in the region where the 8a and 8b are formed, and the labor of performing a light etching process or the like (see FIG. 2F) can be saved, the manufacturing process of the electronic element can be simplified. .

  Such a material distribution in the film thickness direction can be formed by performing a vacuum film forming process such as a co-evaporation method or a co-sputtering method using two or more kinds of electrode materials. In addition, a conductive material solution containing two or more kinds of electrode materials is prepared, applied to the substrate 1, and a non-uniform dispersion state of each electrode material is utilized, whereby the material distribution in the film thickness direction. It is also possible to form

  Moreover, in the above description, as shown in FIG. 2E, in the case where the light etching is performed in order to remove the coating liquid 14a remaining on both side surfaces of the insulating layer 4 in the printing process of the coating liquid 14. However, instead of performing such an etching process, an appropriate voltage is applied between the electrode layer 6 and the electrode layer 7 to form a thin film with the coating liquid remaining on both side surfaces of the conductive layer 4. The conductive layer may be broken. Since the conductive layer formed in the insulating part B1 is thinner than the conductive layer 5, the electrode layer 6 and the electrode layer 7 and has a larger resistance value, an appropriate voltage is applied between the electrode layer 6 and the electrode layer 7. Then, the conductive layer formed in the insulating part B1 can be burned out. By performing such treatment, the conductive layer 5, the electrode layer 6, and the electrode layer 7 may be formed.

  In the above description, after the insulating layer 4 is formed, the conductive layer 5, the electrode layer 6 and the electrode layer 7 are formed with the surface on which the insulating layer 4 is formed facing upward. The conductive layer 5, the electrode layer 6, and the electrode layer 7 may be formed with the electrode layer 4 facing downward.

  Generally, the viscosity of the conductive material coating solution is about 0.1 (Pa · s) (= 100 (cP)) or 0.1 (Pa · s) or less.

  The surface energy on the side surface of the insulating part B1 that forms the channel 8a and the channel 8b is sufficiently small. Compared with this surface energy, the surface of the insulating layer 4 where the conductive layer 5, the electrode layer 6 and the electrode layer 7 are formed. If the conductive material is formed with the insulating layer 4 facing downward when the surface energy is sufficiently large, the conductive material hardly adheres to the insulating layer 4 constituting the insulating portion B1, and even if it adheres, the conductive material itself It moves to the top of the conductive layer 5 due to the gravity acting on. For this reason, the conductive material does not adhere to the insulating portion B1, or even if it adheres, the film thickness is thinner than the conductive layer 5, the electrode layer 6, and the electrode layer 7, and thus the mildness shown in FIG. This etching process can be simplified.

  As a printing method for producing the conductive layer 5 or the like with the production surface facing vertically downward as described above, a coating solution having a low coating solution viscosity such as a flexographic printing method, an ink jet method, or a spray coating method can be applied. A printing method is preferred.

Embodiment 2
The electronic device of the second embodiment is implemented in that only the insulating layer 23 is formed on the electrode layer 2 (that is, the insulating portion A2 (first insulating portion) is formed of only one insulating layer). This is different from the electronic device of Form 1.

  FIG. 10A is a view schematically showing a cross-sectional structure of the electronic device of the second embodiment, and FIG. 10B is a cross-sectional view conceptually showing a main part of the electronic device shown in FIG. It is.

  In the figure, the same components as those of the electronic device of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. For convenience of explanation, the power source is omitted. Since the manufacturing method, operation principle, and dynamic characteristic evaluation are also the same as those of the electronic device of the first embodiment, description thereof is omitted.

  As shown in FIG. 10A, the electronic device of this embodiment has an electrode layer 2 on a substrate 1.

  An insulating layer 23 (first insulating layer) is formed on the upper surface 2 a of the electrode layer 2. This insulating layer 23 is formed by removing the resist used when forming the electrode layer 2 without removing it, like the insulating layer 3 in the first embodiment. The relative dielectric constant and film thickness of this resist will be described later.

  The insulating layer 23 can be formed of an insulating resist material such as a positive resist TSMR8800 manufactured by Tokyo Ohka Kogyo Co., Ltd.

  Insulating layers 24a and 24b (second layers) are formed in an inverted L-shaped region extending from the side surface 2b of the electrode layer 2 to the upper surface of the substrate 1 and an L-shaped region extending from the side surface 2c of the electrode layer 2 to the upper surface of the substrate 1. Insulating layers) are respectively formed. In the present embodiment, the second insulating layer is not formed on the insulating layer 23.

  For this reason, as shown in FIG.10 (b), in this Embodiment, insulating part A2 (1st insulating part) is comprised only by the insulating layer 23 represented with a broken line. Further, the insulating part B2 (second insulating part) is a portion formed on the side surface 2b side of the electrode layer 2 and the side surface 2c side of the L-shaped insulating layers 24a and 24b (indicated by a one-dot chain line in the figure). The part indicated by

  As shown in FIG. 10A, the conductive layer 5 is formed on the insulating layer 23. Although FIG. 1 shows that the conductive layer 5 is also formed on the left and right sides of the insulating layer 23 in the portions having the thickness of the insulating layers 24a and 24b, actually, the thickness of the insulating layers 24a and 24b is shown. Is negligible compared to the width E of the electrode layer 2. The conductive layer 5 only needs to be formed on at least the insulating layer 23, and may or may not be formed in the film thickness portions of the insulating layers 24a and 24b.

  Similarly to the first embodiment, the electrode layer 6 and the electrode layer 7 are formed adjacent to the side surface 2b side and the side surface 2c side of the electrode layer 2 in plan view.

  Similarly, the semiconductor layer 8 is formed in a region covering the insulating part B2 between the conductive layer 5 and the electrode layer 6 and a region covering the insulating part B2 between the conductive layer 5 and the electrode layer 7. ing. The channel is formed in each of these two regions as in the first embodiment.

  Here, the relationship between the film thickness and the dielectric constant between the insulating part A2 and the insulating part B2 will be described.

  As described above, the insulating part A2 of the present embodiment is composed of only the insulating layer 23. The insulating part B2 is composed of portions formed on the side surface 2b and the side surface 2c of the electrode layer 2 in the insulating layers 24a and 24b.

  In order to improve the high-speed response as an electronic element, it is necessary to reduce the electrostatic capacity in the element. In particular, in order to reduce the parasitic capacitance of the insulating portion A2 between the electrode layer 2 and the conductive layer 5, the relative dielectric constant and film thickness of the insulating portion A2 are the same as those of the insulating portion B2. In addition, the capacitance is higher than that of an insulating layer having the same relative dielectric constant (that is, the insulating portion A2 is formed of an insulating layer having the same relative dielectric constant and the same film thickness as the insulating layer 4). It is necessary to set it to be smaller.

  The insulating part A1 of the present embodiment is composed of only the insulating layer 23. For this reason, in order to reduce the parasitic capacitance of the insulating part A2, the relative dielectric constant and film thickness of the insulating layer 23 are set in consideration of the ratio of the relative dielectric constant between the insulating layer 23 and the insulating layer 4 and The capacitance needs to be set to be smaller than “the capacitance of the insulating portion A2 in the case where the insulating layer has the same film thickness and the same dielectric constant as the insulating portion B2”.

  As described above, according to the electronic device of the second embodiment, by using the organic semiconductor material and reducing the parasitic capacitance in the device, it is possible to provide an electronic device that can be manufactured at a low cost and has a high speed response. Can do. Further, since the insulating portion A2 is configured only by the insulating layer 23 used as a resist, the capacitance of the insulating portion A2 can be set more easily.

Embodiment 3
The electronic device according to the third embodiment is implemented in that the electrode layer 37 is continuously formed over the region on the substrate 1 through the insulating portion B3 on the side surface 2c side of the electrode layer 2 from the insulating portion A3. It is different from the electronic device of form 1. For this reason, the channel is formed on the side surface 2 b side of the electrode layer 2.

<Configuration of electronic element>
FIG. 11A schematically shows the structure of the electronic device of the third embodiment, and FIG. 11B conceptually shows an enlarged main part of the electronic device shown in FIG. It is sectional drawing.

  The electronic device of the third embodiment has the same configuration as the electronic device of the first embodiment except that the configuration of the electrode layer 37 (third electrode layer) and the semiconductor layer 38 is different. For this reason, constituent elements other than the electrode layer 37 and the semiconductor layer 38 are denoted by the same reference numerals as those of the electronic element of the first embodiment (except for the insulating part A3 and the insulating part B3), and the description thereof is omitted. . The insulating part A3 (first insulating part) and the insulating part B3 (second insulating part) shown in FIG. 11B correspond to the insulating part A1 and the insulating part B1 shown in FIG.

  As shown in FIG. 11A, the electrode layer 37 is continuously formed from the upper surface of the insulating layer 4 to the upper surface of the substrate 1 through the side surface 2c. The electronic element of the present embodiment has a configuration in which the conductive layer 5 and the electrode layer 7 shown in FIG. 1 are continuously formed.

  Further, the semiconductor layer 38 is formed on the substrate 1 on the side surface 2c side from the region covering the insulating portion B3 between the electrode layer 6 and the electrode layer 37, through the upper surface of the electrode layer 37 and the side surface 2c side. The electrode layer 37 is formed over the upper surface.

  Here, the semiconductor layer 38 is not necessarily formed on the upper surface of the electrode layer 37, the side surface 2 c, and the region on the substrate 1 that is continuous therewith, and at least between the electrode layer 6 and the electrode layer 37. What is necessary is just to be formed in the area | region which covers this insulating part B3.

<Method for manufacturing electronic device>
Next, the manufacturing method of the electronic device of Embodiment 3 is demonstrated using FIG.

  Since the manufacturing method of the electronic device according to the third embodiment is basically the same as the manufacturing method of the electronic device according to the first embodiment shown in FIG.

  The process from FIG. 12A to FIG. 12D is the same as the process shown in FIG. 2A to FIG. 2D, and at the stage shown in FIG. Electrode layer 2, insulating layer 3, and insulating layer 4 are formed as shown.

  Following this, in the step shown in FIG. 12E, a conductive layer 30 made of the same conductive film as the electrode conductive layer 11 is formed on the insulating layer 4.

  Here, a method for forming the conductive layer 30 will be described with reference to FIGS. For convenience of explanation, FIG. 13 is a perspective view showing an electronic element in a manufacturing stage from the side.

  FIGS. 13A and 12D show an electronic device in the same manufacturing stage.

  As shown in FIG. 13 (b), the printing plate 16 coated with the coating liquid 30a for producing the conductive layer 30 is rotated by a roller 15 of a printing machine (not shown), so that it is shown in FIG. 13 (c). Next, the coating liquid 30 a is printed on the insulating layer 4. FIG. 12 (e) shows the side surface of the electronic element at the stage where printing of the coating liquid 30 is completed, and a small amount of the coating liquid 30 a is applied to both side surfaces of the insulating layer 4.

  When the coating liquid 30a applied on the insulating layer 4 is slightly etched as shown in FIG. 12 (e) and the coating liquid 30a applied to both sides of the insulating layer 4 is removed, As shown in FIG. 12 (f), the electrode layer 6 and the electrode layer 37 can be formed.

  Here, the application direction (printing direction) of the coating liquid 30a shown in FIG. 13 differs from the direction of applying the coating liquid 14a in the electronic device of Embodiment 1 shown in FIG. It is a direction straddling the electrode layer 2 in a shape. This is because the electrode layer 37 is continuously formed from the upper surface of the insulating layer 4 to the upper surface of the substrate 1 through the side surface 2c as described above. At this time, in the printing direction shown in FIG. 13, the coating liquid 30a is applied to the side surface on the near side of the electrode layer 2, while the coating liquid 30a is hardly applied to the side surface on the opposite side. By utilizing this property, the coating liquid 30a can be applied as shown in FIG.

  In addition, as a printing method for applying the coating liquid 30a, for example, a printing method using a relief plate such as a flexographic printing method can be used as in the first embodiment.

  Finally, as shown in FIG. 12G, the semiconductor layer 8 is formed. As described above, in forming the semiconductor layer 8, it is necessary to connect at least the electrode layer 6 and the electrode layer 37.

  Through the above manufacturing process, the electronic device of this embodiment can be manufactured.

<Operating Principle of Electronic Device>
When a negative voltage is applied to the electrode layer 2 by the power source 9, holes gather at the boundary between the electrode layer 6 and the electrode layer 37 and the insulating portion B3 in the semiconductor layer 38, and a hole channel 38a is formed. In the electronic device of the present embodiment, the channel is formed only between the electrode layer 6 and the electrode layer 37.

  At this time, when the second power source 10 is turned on and a voltage is applied between the electrode layer 6 and the electrode layer 7 so that the electrode layer 7 is negative, holes are transferred from the electrode layer 6 to the electrode layer 37 through the channel 38a. Flowing. That is, the electronic device of this embodiment is a field effect transistor in which the electrode layer 2 is a gate electrode, the electrode layer 6 is a source electrode, and the electrode layer 7 is a drain electrode.

  Although an equivalent circuit diagram of the electronic device of this embodiment is omitted, unlike the electronic device of Embodiment 1, the equivalent circuit includes one transistor.

  Since the cut-off frequency has been confirmed to be the same level as that of the electronic device of the first embodiment, the dynamic characteristic evaluation is omitted.

  As described above, according to the electronic element of the present embodiment, by using the organic semiconductor material and reducing the parasitic capacitance in the element, it is possible to provide an electronic element that can be manufactured at low cost and has high-speed response. .

<Modification>
FIG. 14 is a diagram illustrating a modification of the electronic device of the third embodiment. 14A and 14B, the first power source and the second power source are omitted, and in FIGS. 14C and 14D, the substrate 1, the electrode layer 6, and the electrode layer 37 are further omitted.

  The electronic element shown in FIG. 14A includes the insulating layer 4 between the substrate 1 and the electrode layer 6 and between the substrate 1 and the electrode layer 37. Since the thickness of the insulating layer 4 is almost negligible compared to the thickness of the electrode layer 2, even with such an electronic device, the capacitance of the insulating portion A 3 can be reduced, and an electron with good high-speed response. An element can be provided.

  The electronic element shown in FIG. 14B includes the same insulating layers 3 b and 3 c as the insulating layer 3 a between the substrate 1 and the insulating layer 4. Since the thickness of the insulating layers 3b and 3c is almost negligible compared to the thickness of the electrode layer 2, the electronic element having such a configuration can reduce the capacitance of the insulating portion A3 and has good high-speed response. An electronic device can be provided.

  As shown in FIGS. 14C and 14D, the cross-sectional shape of the insulating layer 3 may be a substantially semicircular shape or a trapezoidal shape with chamfered corners.

  With such a shape, as shown in FIG. 14A, the length F of the channel 38a is extended by the film thickness of the insulating layer 4 as compared with the case where the cross-sectional shape of the electrode layer 2 is rectangular. Since it can be minimized, the channel length can be shortened.

  Thus, by shortening the distance between the conductive layer 5 and the electrode layer 6, the resistance value between the conductive layer 5 and the electrode layer 6 can be reduced, and the electrode layer 2 is used as a gate. In this case, the capacitance of the channel 38a can be reduced, so that the cut-off frequency can be improved and better high-speed response can be obtained.

Embodiment 4
In the electronic device of the fourth embodiment, only the insulating layer 43 is formed on the electrode layer 2 (that is, the insulating portion A4 is formed of only one insulating layer), and the electrode layer 47 is It differs from the electronic device of the first embodiment in that it is continuously formed over the region on the substrate 1 through the insulating part B4 on the side surface 2c side of the electrode layer 2 from above the insulating part A4. For this reason, the channel is formed on the side surface 2 b side of the electrode layer 2.

<Configuration of electronic element>
FIG. 15A is a view schematically showing a cross-sectional structure of the electronic device of the fourth embodiment, and FIG. 15B is a cross-sectional view conceptually showing a main part of the electronic device shown in FIG. It is.

  In the figure, the same components as those of the third embodiment are denoted by the same reference numerals, and the description thereof is omitted. For convenience of explanation, the power source is omitted. Since the manufacturing method, operation principle, and dynamic characteristic evaluation are also the same as those of the electronic device of the third embodiment, description thereof is omitted.

  As shown in FIG. 15, the electronic device of the present embodiment has an electrode layer 2 on a substrate 1.

  An insulating layer 43 (first insulating layer) is formed on the upper surface 2 a of the electrode layer 2. This insulating layer 43 is formed by removing the resist used when forming the electrode layer 2 without removing it, like the insulating layer 3 in the third embodiment. The relative dielectric constant and film thickness of this resist will be described later.

  The insulating layer 43 can be formed of an insulating resist material such as a positive resist TSMR8800 manufactured by Tokyo Ohka Kogyo Co., Ltd.

  Insulating layers 44a and 44b (second layers) are formed in the inverted L-shaped region extending from the side surface 2b of the electrode layer 2 to the upper surface of the substrate 1 and the L-shaped region extending from the side surface 2c of the electrode layer 2 to the upper surface of the substrate 1. Insulating layers) are formed. In the present embodiment, an insulating layer is not formed over the insulating layer 43.

  For this reason, as shown in FIG. 15B, in the present embodiment, the insulating portion A4 (first insulating portion) is constituted only by the insulating layer 43 represented by a broken line. Also, the insulating part B4 (second insulating part) is a portion formed on the side surface 2b side of the electrode layer 2 and the side surface 2c side of the L-shaped insulating layers 44a and 44b (indicated by a one-dot chain line in the figure). The part indicated by

  The electrode layer 47 is continuously formed from the upper surface of the insulating layer 43 so as to cover the L-shaped insulating layer 44b. The electronic element of the present embodiment has a configuration in which the conductive layer 5 and the electrode layer 7 shown in FIG. 10 are continuously formed.

  Further, the semiconductor layer 48 is formed on the side surface through the upper surface of the electrode layer 47 and the side surface 2c formed on the upper surface side of the insulating portion A4 from the region covering the insulating portion B4 between the electrode layer 6 and the electrode layer 47. It is formed over the upper surface of the electrode layer 47 formed on the substrate 1 on the 2c side.

  Here, the semiconductor layer 48 is not necessarily formed on the upper surface of the electrode layer 47, the side surface 2 c, and the region on the substrate 1 that is continuous therewith, and at least between the electrode layer 6 and the electrode layer 47. As long as it is formed in a region covering the insulating part B4 (insulating part B4 on the side of the side surface 2b).

  In such an electronic device of the present embodiment, as in the electronic device of the third embodiment, when a negative voltage is applied to the electrode layer 2, the insulation in the semiconductor layer 48 is between the electrode layer 6 and the electrode layer 47. Holes gather at the boundary with the part B4 to form a hole channel 48a. In the electronic device of the present embodiment, the channel is formed only between the electrode layer 6 and the electrode layer 47.

  Here, the relationship between the film thickness and the dielectric constant between the insulating part A4 and the insulating part B4 will be described.

  As described above, the insulating portion A4 of the present embodiment is composed of only the insulating layer 43. The insulating part B4 is constituted by portions formed on the side surface 2b and the side surface 2c of the electrode layer 2 in the insulating layers 44a and 44b.

  In order to improve the high-speed response as an electronic element, it is necessary to reduce the electrostatic capacity in the element. In particular, in order to reduce the parasitic capacitance of the insulating part A4 between the electrode layer 2 and the conductive layer 5, the insulating part A4 has the same dielectric constant and film thickness as the insulating part A4. And an insulating layer having the same relative dielectric constant (that is, the insulating portion A4 is made of an insulating layer having the same relative dielectric constant and the same film thickness as the insulating layers 44a and 44b). It is necessary to set the capacity to be small.

  Since the insulating portion A4 of the present embodiment is composed of only the insulating layer 43, in order to reduce the parasitic capacitance of the insulating portion A4, the relative dielectric constant and film thickness of the insulating layer 43 are insulated from the insulating layer 43. It needs to be determined in view of the ratio of the relative permittivity with the layers 44a and 44b. In other words, the insulating part A4 is insulated so that the electrostatic capacity becomes smaller than “the electrostatic capacity of the insulating part A4 when the insulating part A4 is composed of an insulating layer having the same film thickness and the same dielectric constant”. It is necessary to set the relative dielectric constant and film thickness of the layer 43.

  As described above, according to the electronic device of the fourth embodiment, it is possible to manufacture at low cost by reducing the parasitic capacitance of the first insulating portion formed between the gate electrode and the conductive layer while using the organic semiconductor material. It is possible to provide an electronic device that is capable of high-speed response. Further, since the insulating portion A4 is configured only by the insulating layer 43 used as a resist, the capacitance of the insulating portion A4 can be set more easily.

  As mentioned above, although the electronic device of the exemplary embodiment of the present invention has been described, the present invention is not limited to the specifically disclosed embodiment, and without departing from the scope of the claims. Various modifications and changes are possible.

  The electronic element of the present invention can be used for a liquid crystal display device, an organic EL display device, an IC tag, or the like.

(A) is a figure which shows roughly the cross-section of the electronic device of Embodiment 1, (b) is sectional drawing which expands and principally shows the principal part of the electronic device shown to Fig.1 (a), (C) is a conceptual diagram for demonstrating the channel formed in an electronic element. It is a figure which shows the manufacturing process of the electronic device of Embodiment 1 in steps. It is a figure which shows the manufacturing process of the resist using microprinting method in steps. FIG. 3 is a diagram showing a step of printing a conductive layer in the electronic device of the first embodiment. FIG. 3 is a diagram illustrating an equivalent circuit of the electronic element according to the first embodiment. FIG. 3 is a diagram illustrating a state in which a driving device and a measurement device are connected to the electronic element of the first embodiment. FIG. 3 is a diagram illustrating dynamic characteristics of the electronic device of the first embodiment. FIG. 6 is a main part sectional view showing a modification of the first insulating layer of the electronic element of the first embodiment. FIG. 6 is a main part sectional view showing a modification of the first electrode layer of the electronic element of the first embodiment. (A) is a figure which shows schematically the cross-section of the electronic device of Embodiment 2, (b) is sectional drawing which shows notionally the principal part of the electronic device shown to Fig.10 (a). (A) is a figure which shows roughly the structure of the electronic device of Embodiment 3, (b) is sectional drawing which expands and principally shows the principal part of the electronic device shown to Fig.11 (a). . It is a figure which shows the manufacturing process of the electronic device of Embodiment 3 in steps. It is a figure which shows the printing process of the conductive layer in the electronic device of Embodiment 3 in steps. It is a figure which shows the modification of the electronic device of Embodiment 3. FIG. (A) is a figure which shows schematically the cross-section of the electronic device of Embodiment 4, (b) is sectional drawing which shows notionally the principal part of the electronic device shown to Fig.15 (a). (A) is a figure which shows the cross-sectional structure of the conventional planar type transistor, (b) is a figure which shows the cross-sectional structure of the conventional reverse stagger type transistor.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Board | substrate 2, 6, 7, 37, 47 ... Electrode layer, 2a ... Upper surface, 2b, 2c ... Side surface 3, 3a, 4, 23, 24a, 24b, 43, 44a, 44b ... Insulating layer, 5 ... Conductive layer, 8, 38, 48 ... semiconductor layer, 8a, 8b, 48a ... channel, 9, 10 ... power source, A1, A2, A3, A4, B1, B2, B3, B4 ... insulating portion.

Claims (7)

A linear first electrode formed on a substrate and having an upper surface, a first side surface and a second side surface;
A film-like first insulating part formed on the upper surface of the first electrode;
A film-like second insulating part formed on the first and second side surfaces of the first electrode adjacent to the first insulating part;
A conductive layer formed on an upper surface of the first insulating portion;
A second electrode formed in a region on the substrate and adjacent to the second insulating portion on the first side surface in plan view;
A third electrode formed in a region on the substrate and adjacent to the second insulating portion on the second side surface in plan view;
A region covering the second insulating part between the conductive layer and the second electrode, and a semiconductor layer formed in a region covering the second insulating part between the conductive layer and the third electrode; With
The first insulating part has a film thickness and relative dielectric constant with a smaller capacitance than when the first insulating part is composed of an insulating layer having the same film thickness and the same dielectric constant as the second insulating part. An electronic device comprising: an insulating layer having a ratio ; and wherein the first insulating portion includes an insulating resist layer used when forming the first electrode . A linear first electrode formed on a substrate and having an upper surface, a first side surface and a second side surface;
A film-like first insulating part formed on the upper surface of the first electrode;
A film-like second insulating part formed on the first and second side surfaces of the first electrode adjacent to the first insulating part;
A conductive layer formed on an upper surface of the first insulating portion;
A second electrode formed in a region on the substrate and adjacent to the second insulating portion on the first side surface in plan view;
A third electrode formed in a region on the substrate and adjacent to the second insulating portion on the second side surface in plan view;
A region covering the second insulating part between the conductive layer and the second electrode, and a semiconductor layer formed in a region covering the second insulating part between the conductive layer and the third electrode; With
The first insulating part has a film thickness and relative dielectric constant with a smaller capacitance than when the first insulating part is composed of an insulating layer having the same film thickness and the same dielectric constant as the second insulating part. The first insulating portion is a stacked body including a plurality of insulating layers, and the lowest layer has an insulating property used when forming the first electrode. An electronic device comprising a resist layer . A linear first electrode formed on a substrate and having an upper surface, a first side surface and a second side surface;
A film-like first insulating part formed on the upper surface of the first electrode;
A film-like second insulating part formed on the first and second side surfaces of the first electrode adjacent to the first insulating part;
A second electrode formed in a region on the substrate and adjacent to the second insulating portion on the first side surface in plan view;
A third electrode formed continuously over the region on the substrate from the upper surface of the first insulating portion through the second side surface;
A semiconductor layer formed in a region covering the second insulating portion between the second electrode and the third electrode;
The first insulating part has a film thickness and relative dielectric constant with a smaller capacitance than when the first insulating part is composed of an insulating layer having the same film thickness and the same dielectric constant as the second insulating part. An electronic device comprising: an insulating layer having a ratio ; and wherein the first insulating portion includes an insulating resist layer used when forming the first electrode . A linear first electrode formed on a substrate and having an upper surface, a first side surface and a second side surface;
A film-like first insulating part formed on the upper surface of the first electrode;
A film-like second insulating part formed on the first and second side surfaces of the first electrode adjacent to the first insulating part;
A second electrode formed in a region on the substrate and adjacent to the second insulating portion on the first side surface in plan view;
A third electrode formed continuously over the region on the substrate from the upper surface of the first insulating portion through the second side surface;
A semiconductor layer formed in a region covering the second insulating portion between the second electrode and the third electrode;
The first insulating part has a film thickness and relative dielectric constant with a smaller capacitance than when the first insulating part is composed of an insulating layer having the same film thickness and the same dielectric constant as the second insulating part. The first insulating portion is a stacked body including a plurality of insulating layers, and the lowest layer has an insulating property used when forming the first electrode. An electronic device comprising a resist layer . Wherein the resist other than the layer insulating layer, an electronic device according to claim 2 or 4, characterized in that includes an insulating layer formed integrally with the second insulating portion. The resist layer can be an electron device according to any one of claims 1 to 5, characterized in that the cross-sectional shape is trapezoidal lower base is longer than the semi-circular or upper base.   The electronic device according to claim 1, wherein the first electrode has a rectangular shape or a reverse tapered shape in cross section.

Images