JP7638536B2 - Semiconductor device and its manufacturing method - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act (1) Disclosure 1 ▲1▼ Publication date: February 28, 2020 ▲2▼ Publication: Proceedings of the 67th Spring Meeting of the Japan Society of Applied Physics ▲3▼ Discloser: Kitahara Akira, Inoue Satoru, Higashino Hisaki, Ikawa Mitsuhiro, Matsuoka Satoshi, Arai Toshihito, and Hasegawa Tatsuo ▲4▼ Disclosed content of invention: Kitahara Akira et al. have disclosed part of the research on the semiconductor device and its manufacturing method invented by Hasegawa Tatsuo, Kitahara Akira, Inoue Satoru, Arai Toshihito, and Ikawa Mitsuhiro in the Proceedings of the 67th Spring Meeting of the Japan Society of Applied Physics.

Application of Article 30, Paragraph 2 of the Patent Act (2) Disclosure 2 ▲1▼ Publication date: August 26, 2020 ▲2▼ Publication: Proceedings of the 81st Autumn Meeting of the Japan Society of Applied Physics ▲3▼ Discloser: Kitahara Akira, Inoue Satoru, Higashino Hisaki, Ikawa Mitsuhiro, Matsuoka Satoshi, Arai Toshihito, and Hasegawa Tatsuo ▲4▼ Disclosed content of invention: Kitahara Akira et al. disclosed part of the research on the semiconductor device and its manufacturing method invented by Hasegawa Tatsuo, Kitahara Akira, Inoue Satoru, Arai Toshihito, and Ikawa Mitsuhiro in the Proceedings of the 81st Autumn Meeting of the Japan Society of Applied Physics.

Application of Article 30, Paragraph 2 of the Patent Act (3) Disclosure3 ▲1▼ Date: September 9, 2020 ▲2▼ Name and location of meeting: 81st Autumn Meeting of the Japan Society of Applied Physics (September 8-11, 2020, held online) ▲3▼ Disclosers: Kitahara Akira, Inoue Satoru, Higashino Hisaki, Ikawa Mitsuhiro, Matsuoka Satoshi, Arai Toshihito, and Hasegawa Tatsuo ▲4▼ Disclosed invention: Kitahara Akira et al. disclosed part of the research on the semiconductor device and its manufacturing method invented by Hasegawa Tatsuo, Kitahara Akira, Inoue Satoru, Arai Toshihito, and Ikawa Mitsuhiro at the 81st Autumn Meeting of the Japan Society of Applied Physics.

(4) Publication 4 ▲1▼ Date of website posting: October 7, 2020 ▲2▼ Website address: https://www.science.org/doi/epdf/10.1126/sciadv. abc8847 ▲3▼ Disclosure: Akira Kitahara, Satoru Inoue, Hisaki Higashino, Mitsuhiro Ikawa, Taichi Hayashi, Satoshi Matsuoka, Toshihito Arai, and Tatsuo Hasegawa ▲4▼ Disclosed content of the invention: Akira Kitahara et al. have disclosed part of the research on the semiconductor device and its manufacturing method invented by Tatsuo Hasegawa, Akira Kitahara, Satoru Inoue, Toshihito Arai, and Mitsuhiro Ikawa on the website at the above address (Science Advances online edition, Sci. Adv. 2020; 6: eabc8847).

Article 30, paragraph 2 of the Patent Act applies (5) Disclosure 5 ▲1▼ Date of website posting: October 8, 2020 ▲2▼ Website address: https://www.t.u-tokyo.ac.jp/hubfs/shared-old/press/data/setnws_202010081143074640368929_710188.pdf ▲3▼ Disclosure: National University Corporation, University of Tokyo ▲4▼ Disclosure of invention: National University Corporation, University of Tokyo has disclosed a part of the research on the semiconductor device and its manufacturing method invented by Tatsuo Hasegawa, Akira Kitahara, Satoru Inoue, Toshihito Arai, and Mitsuhiro Ikawa as a press release on the website at the above address.

One aspect of the present invention relates to a semiconductor device including a thin film transistor. Another aspect of the present invention relates to a method for manufacturing the semiconductor device using a coating process.

An organic semiconductor film can be formed by dissolving an organic semiconductor compound in a solvent and applying the resulting solution. Whereas a vacuum process is required to form an inorganic semiconductor film made of silicon or the like, an organic semiconductor film can be formed without using such a vacuum process. Therefore, the manufacturing cost is relatively low. In addition, since there is no need to reduce the pressure inside the chamber in which the film is formed, it is relatively easy to form the organic semiconductor film in a large chamber. In this case, it is possible to mass-produce a large-area semiconductor element containing an organic semiconductor film. In addition, the organic semiconductor film is formed without using a high-temperature heating process required to form an inorganic semiconductor film. Therefore, the substrate on which the organic semiconductor film is formed is not limited to a heat-resistant substrate, and may be a flexible substrate made of a relatively inexpensive plastic material. As a result, it is now possible to manufacture flexible devices, which were difficult when using semiconductor elements containing inorganic semiconductor films. Under these circumstances, research and development of semiconductor elements containing organic semiconductor films and devices containing them is becoming more and more popular.

An example of a semiconductor element containing an organic semiconductor film is a thin-film transistor in which a channel is formed in the organic semiconductor film. To put such transistors into practical use, it is important to establish their manufacturing process (e.g., a technique for selectively applying an organic semiconductor layer only to the area that functions as the channel) and characteristics (e.g., high carrier mobility, no hysteresis occurring when switching from on to off or vice versa (hysteresis-free), and a rapid change in drain current near the threshold voltage).

In a thin-film transistor, a gate electrode film and a semiconductor film are arranged to overlap with each other with a gate insulating film interposed between them. In general, a structure (bottom-gate structure) is often adopted in which the semiconductor film is arranged on the gate electrode film with the gate insulating film interposed between them. Then, depending on the voltage applied to the gate electrode film, it is determined whether or not a carrier channel is formed in the region of the semiconductor film near the gate insulating film. Here, carrier conduction in the organic semiconductor film included in the thin-film transistor is strongly influenced by the physical and chemical properties of the gate insulating film at the interface with the organic semiconductor film.

For example, Patent Document 1 discloses that when SiO ₂ is used as a gate insulating film, hydroxyl groups, oxygen, and water present on the surface become trap sites for carrier conduction. As a means for improving the surface of such a gate insulating film, for example, Non-Patent Document 1 discloses that a process for forming a self-assembled monolayer (SAM process) on the interface of the gate insulating film is effective. In addition, Non-Patent Document 2 discloses that an organic thin-film transistor using a highly water-repellent fluororesin (Cytop (registered trademark)) as a gate insulating film and a rubrene single crystal as an organic semiconductor film exhibits hysteresis-free and extremely steep switching characteristics. However, the surface of such a gate insulating film has extremely high liquid repellency against the organic semiconductor film. Therefore, patterning of the organic semiconductor film on such a gate insulating film is performed through a complicated process described later.

Known techniques for patterning organic semiconductor films include, for example, a method using a photophilic/phobic pattern and a method using a bank.

As a method of using the affinity-repellency pattern, a method of patterning by various means after performing SAM processing on the gate insulating film interface is known. For example, Patent Document 1 and Non-Patent Document 3 disclose that the entire surface of the gate insulating film is made lyophilic by exposure processing except for the area that will become the channel formation area after SAM processing. This suppresses the repulsion of the solution containing the material constituting the applied organic semiconductor film as a solute at the area where the exposure processing has been performed. Furthermore, it is possible to leave the organic semiconductor film without being repelled even in the area surrounded by the area where the exposure processing has been performed. On the other hand, Non-Patent Document 4 discloses that only the area that will become the channel formation area after SAM processing on the entire surface of the gate insulating film is made lyophilic by exposure processing. This makes it possible to apply a solution containing the material constituting the organic semiconductor film as a solute only to the area where the exposure processing has been performed. Furthermore, Patent Document 2 discloses a method of forming an affinity-repellency pattern using the change in density of a self-assembled monolayer, and applying a solution containing the material constituting the organic semiconductor film as a solute only to the lyophilic part.

As a method of using a bank, a method is known in which a bank is formed using a photolithography process, and the bank inhibits the flow of a solution containing the material constituting the organic semiconductor film as a solute, thereby forming an organic semiconductor film at a desired position. For example, Non-Patent Document 5 discloses the use of a fluororesin as the bank in the process.

JP 2009-60032 A JP 2008-192724 A

J. Mater. Chem. 20, 2549-2561 (2010) Phys. Rev. Appl. 1,034006 (2014) ACS App. Mater. Interfaces 9, 6237-6245 (2017) Nature. 475, 364-367 (2011). Nat. Commun. 5, 4147 (2014).

One aspect of the present invention aims to provide a semiconductor device including a thin film transistor that can be manufactured more easily than conventional methods.

The inventors have discovered that, prior to depositing an organic semiconductor film on an insulating film that is lyophobic to a solvent that is the main component of a solution containing the material that constitutes the organic semiconductor film as a solute, the organic semiconductor film can be deposited in a desired position, for example, in the channel formation region of a transistor, by depositing a conductive film in a desired shape that is lyophilic to the solvent.

That is, the gist of the semiconductor device of one embodiment of the present invention is that a conductive film functioning as a source and drain has a desired shape on an insulating film that functions as a gate insulating film and is located in a layer below an organic semiconductor film, or a conductive film having a desired shape is provided separately from the conductive film that functions as a source and drain. Also, the gist of the manufacturing method of the semiconductor device of one embodiment of the present invention is that a conductive film functioning as a source and drain is formed in a desired shape on an insulating film that functions as a gate insulating film and is located in a layer below an organic semiconductor film, or a conductive film having a desired shape is formed separately from the conductive film that functions as a source and drain.

For example, a semiconductor device including a first conductive film, an insulating film on the first conductive film, a second conductive film and a third conductive film on the insulating film, and an organic semiconductor film on the insulating film, the second conductive film, and the third conductive film, wherein the second conductive film includes a portion extending along a first direction, and the third conductive film includes a first portion located in the first direction as viewed from the second conductive film, a second portion located in a second direction perpendicular to the first direction as viewed from a region between the second conductive film and the first portion, and a third portion located in a third direction that is the opposite direction to the second direction, a fourth portion located in a fourth direction that is the opposite direction to the first direction as viewed from the second portion, and a fifth portion located in the fourth direction as viewed from the third portion, wherein at least a portion of the first portion and the second portion and at least a portion of the third portion extend continuously, and the surface free energy of the insulating film is smaller than the surface free energy of the second conductive film and the surface free energy of the third conductive film, is one aspect of the present invention.

The method also includes a step of forming a first conductive film, a step of forming an insulating film on the first conductive film, a step of irradiating a first region and a second region of the insulating film with ultraviolet light, a step of forming a second conductive film and a third conductive film on the first region and the second region, respectively, and a step of forming an organic semiconductor film on the insulating film, the second conductive film, and the third conductive film, wherein the first region extends along a first direction, and the second region has a first portion located in the first direction as viewed from the first region, a second portion located in a second direction perpendicular to the first direction as viewed from a region between the first region and the first portion, and a third portion located in a third direction opposite to the second direction. and a fifth portion located in the fourth direction as viewed from the third portion, wherein at least a portion of the first portion, the second portion, and the third portion extend continuously, a contact angle of a solvent that is a main component of a solution containing a material that constitutes the organic semiconductor film as a solute, with respect to the gate insulating film is larger than a contact angle of the solvent with respect to each of the second conductive film and the third conductive film, and the step of forming the organic semiconductor film includes a step of applying the solution along the fourth direction. This is also an aspect of the present invention.

In one aspect of the present invention, it is possible to provide a thin-film transistor having an organic semiconductor film without going through the complicated processes of the conventional method using a photosensitive pattern and the method using a bank.

FIG. 1 is a top view illustrating an example of a semiconductor device of one embodiment of the present invention. A cross-sectional view taken along line A-A' in FIG. 1A. 1B is a top view showing a state in which an organic semiconductor film 7 has been removed from the semiconductor device shown in FIG. 1A. FIG. FIG. 1 is a top view illustrating an example of a semiconductor device of one embodiment of the present invention. Cross-sectional view taken along line B-B' in FIG. 3A. 3B is a top view showing a state in which the organic semiconductor film 25 has been removed from the semiconductor device shown in FIG. 3A. FIG. 1A to 1C are cross-sectional views illustrating an example of a manufacturing method of a semiconductor device of one embodiment of the present invention. 1A to 1C are cross-sectional views illustrating an example of a manufacturing method of a semiconductor device of one embodiment of the present invention. 1A to 1C are cross-sectional views illustrating an example of a manufacturing method of a semiconductor device of one embodiment of the present invention. 1A to 1C are cross-sectional views illustrating an example of a manufacturing method of a semiconductor device of one embodiment of the present invention. 4 is a side view showing an example of a method for applying a solution containing a material constituting a gate electrode film 15 as a solute. FIG. 11A and 11B are top views showing an example of a method for applying a solution containing a material constituting an organic semiconductor film 25 as a solute. Cross-sectional view taken along line C-C' in FIG. 7A. 11A and 11B are top views showing an example of a method for applying a solution containing a material constituting an organic semiconductor film 25 as a solute. Cross-sectional view taken along line C-C' in Figure 8A. 11A and 11B are top views showing an example of a method for applying a solution containing a material constituting an organic semiconductor film 25 as a solute. Cross-sectional view taken along line C-C' in Figure 9A. 11A and 11B are top views showing an example of a method for applying a solution containing a material constituting an organic semiconductor film 25 as a solute. Cross-sectional view taken along line C-C' in Figure 10A. 11A and 11B are top views showing an example of a method for applying a solution containing a material constituting an organic semiconductor film 25 as a solute. Cross-sectional view taken along line C-C' in Figure 10A. 13 is a cross-sectional view showing a modified example of the semiconductor device. 13A and 13B are top views showing modified examples of a conductive film on which an organic semiconductor film is first formed in a semiconductor device. 13A and 13B are top views showing modified examples of a conductive film on which an organic semiconductor film is first formed in a semiconductor device. FIG. 2 is a top view showing a conductive example in which an organic semiconductor film is formed first in a semiconductor device. 4 is a polarizing microscope photograph of the semiconductor device obtained in Example 1. FIG. 4 is a diagram showing the output characteristics of an organic thin-film transistor element included in the semiconductor device obtained in Example 1. FIG. 4 is a diagram showing the transfer characteristics of an organic thin-film transistor element included in the semiconductor device obtained in Example 1. 13 is a polarizing microscope photograph of the semiconductor device obtained in Example 3. FIG. 13 is a diagram showing the output characteristics of an organic thin-film transistor element included in the semiconductor device obtained in Example 3. FIG. 13 is a diagram showing the transfer characteristics of an organic thin-film transistor element included in the semiconductor device obtained in Example 3. 13 is a polarizing microscope photograph of the semiconductor device obtained in Example 6. 13 is a polarizing microscope photograph of the semiconductor device obtained in Example 8. 1 is a polarizing microscope photograph showing a semiconductor film obtained in Example 10. 13 is a polarizing microscope photograph of the semiconductor device obtained in Example 11. 13 is a polarizing microscope photograph of the semiconductor device obtained in Example 13. 13 is a polarizing microscope photograph of the semiconductor device obtained in Example 15. 13 is a polarizing microscope photograph of the semiconductor device obtained in Example 16. 13 is a polarizing microscope photograph of the semiconductor device obtained in Example 17. 4 is a polarizing microscope photograph of the semiconductor device obtained in Comparative Example 1.

1. An Example of a Semiconductor Device (1) Structure A. An example in which a conductive film functioning as a source and a drain has a desired shape Figures 1A and 1B are diagrams showing an example of a semiconductor device according to one embodiment of the present invention. Specifically, Figure 1A is a top view of the semiconductor device, and Figure 1B is a cross-sectional view taken along line A-A' in Figure 1A. Figure 2 is a top view showing a state in which an organic semiconductor film 7 has been removed from the semiconductor device shown in Figure 1A.

1A and 1B includes a substrate 1, an undercoat film 2 on the substrate 1, a conductive film 3 on the undercoat film 2, an insulating film 4 on the conductive film 3, a conductive film 5 and a conductive film 6 on the insulating film 4, and an organic semiconductor film 7 on the insulating film 4, the conductive film 5 and the conductive film 6. The semiconductor device functions as a transistor. Specifically, the conductive film 3 functions as a gate, the conductive film 5 functions as one of the source and drain, and the conductive film 6 functions as the other of the source and drain.

The conductive films 5 and 6 are disposed on the insulating film 4 and separated from each other in a layer below the organic semiconductor film 7. The conductive film 5 includes a portion extending from left to right on the paper surface of FIGS. 1A and 2. The conductive film 6 extends so as to surround the right end of the conductive film 5 on the paper surface of FIGS. 1A and 2. In other words, the conductive film 5 extends along the first direction, and the conductive film 6 includes a first portion 6-1 located in the first direction as viewed from the conductive film 5, a second portion 6-2 located in a second direction perpendicular to the first direction as viewed from the region 8-1 between the conductive film 5 and the first portion 6-1, a third portion 6-3 located in a third direction opposite to the second direction, a fourth portion 6-4 located in a fourth direction opposite to the first direction as viewed from the second portion 6-2, and a fifth portion 6-5 located in the fourth direction as viewed from the third portion 6-3.

The shape of the conductive film 6 shown in Figures 1A and 2 can also be expressed as a "U" shape. Specifically, the conductive film 6 is composed of an upper part and a lower part extending in the direction in which the conductive film 5 extends, i.e., along the first direction and the fourth direction described above, and an intermediate part extending in a direction perpendicular to the direction in which the conductive film 5 extends, i.e., along the second direction and the third direction described above. Typically, the end of the upper part on the first direction side and the end of the intermediate part on the second direction side are continuous, and the end of the lower part on the first direction side and the end of the intermediate part on the third direction side are continuous. However, as long as there is no hindrance to the formation of the organic semiconductor film 6 described later, the end of the upper part on the first direction side and the end of the intermediate part on the second direction side do not necessarily have to be continuous, and there can be a certain amount of space between these ends. Similarly, as long as there is no hindrance to the formation of the organic semiconductor film described later, the end of the lower part on the first direction side and the end of the intermediate part on the third direction side do not necessarily have to be continuous, and there can be a certain amount of space between both ends. The intermediate portion includes a first portion 6-1 shown in Figures 1A and 2. The upper portion includes a second portion 6-2 and a fourth portion 6-4 shown in Figures 1A and 2. The lower portion includes a third portion 6-3 and a fifth portion 6-5 shown in Figures 1A and 2. The conductive film 6 is disposed such that at least a portion of the conductive film 5 is located between the upper portion and the lower portion.

3A and 3B are diagrams showing another example of a semiconductor device according to one embodiment of the present invention. Specifically, Fig. 3A is a top view of the semiconductor device, and Fig. 3B is a cross-sectional view taken along line B-B' in Fig. 3A. Fig. 4 is a top view showing a state in which the organic semiconductor film 25 has been removed from the semiconductor device shown in Fig. 3A.

3A and 3B includes a substrate 11, an undercoat film 13 on the substrate 11, a conductive film 15 on the undercoat film 13, an insulating film 17 on the conductive film 15, conductive films 19, 21, and 23 on the insulating film 17, and an organic semiconductor film 25 on the insulating film 17 and the conductive films 19, 21, and 23. The semiconductor device functions as a transistor. Specifically, the conductive film 15 functions as a gate, the conductive film 19 functions as one of the source and drain, and the conductive film 21 functions as the other of the source and drain.

Conductive films 19, 21, and 23 are disposed on insulating film 17 and separated from one another in a layer below organic semiconductor film 25. Conductive films 19 and 21 include portions that extend approximately parallel from left to right on the paper of Figures 3A and 4. Conductive film 23 extends so as to surround the right ends of conductive films 19 and 21 on the paper of Figures 3A and 4. In other words, the conductive films 19 and 21 extend approximately parallel to the first direction, and the conductive film 23 includes a first portion 23-1 located in the first direction when viewed from the conductive films 19 and 21, a second portion 23-2 located in a second direction perpendicular to the first direction when viewed from a region 30-1 between the conductive films 19 and 21 and the first portion 23-1, a third portion 23-3 located in a third direction that is the opposite direction to the second direction, a fourth portion 23-4 located in a fourth direction that is the opposite direction to the first direction when viewed from the second portion 23-2, and a fifth portion 23-5 located in the fourth direction when viewed from the third portion 23-3.

In addition, the shape of the conductive film 23 shown in Figures 3A and 4 can also be described as being U-shaped, similar to the conductive film 6 shown in Figures 1A and 2.

1A and 1B and 3A and 3B, an insulating film having liquid repellency to a solvent that is a main component of a solution containing, as a solute, the material constituting the organic semiconductor films 7 and 25 is used as the insulating films 4 and 17, and a conductive film having liquid affinity to the solvent is used as the conductive films 5, 6, 19, and 21 functioning as the source and drain, and the conductive film 23. That is, the surface free energy of the insulating films 4 and 17 is smaller than the surface free energy of the conductive films 5, 6, 19, 21, and 23. Therefore, the contact angle of the solvent with respect to the insulating films 4 and 17 is larger than the contact angle of the solvent with respect to each of the conductive films 5, 6, 19, 21, and 23.

The shapes of the conductive films 6 and 23 are not limited to those shown in Figures 1A, 2, 3A, and 4. However, in order to deposit the organic semiconductor film 7 or 25 on the insulating film 4 or 17 in the region between the conductive film 5 and the conductive film 6 (see Figures 1A and 2) or the region between the conductive film 19 and the conductive film 21 (see Figures 3A and 4), which will be the channel formation region of the thin film transistor, the conductive films 6 and 23 need to be deposited in the following shapes.

First, in the film-forming process of the organic semiconductor film 7 or 25 described later, a solution containing the material constituting the organic semiconductor film 7 or 25 as a solute is applied from right to left on the paper surface of Figures 1A, 2, 3A, and 4, that is, along the fourth direction described above. As described above, the insulating films 4 and 17 are liquid-repellent to the solvent that is the main component of the solution, and the conductive films 6 and 23 are lyophilic to the solvent, so that application of the solution is started when the conductive films 6 and 23 come into contact with the solution. In this specification, the start of application means that the solution to be applied is separated and independent from the application member such as a blade or roller and begins to remain on the object to be applied. And, application of the solution must be started before the solution comes into contact with the insulating film 4 or 17 in the region between the conductive film 5 and the conductive film 6 (see Figures 1A and 2) or the region between the conductive film 19 and the conductive film 21 (see Figures 3A and 4), which will be the channel formation region of the thin film transistor. Therefore, the conductive film 6 needs to be formed into a shape that includes a portion (e.g., first portion 6-1) existing in the first direction when viewed from the conductive film 5. Similarly, the conductive film 23 needs to be formed into a shape that includes a portion (e.g., first portion 23-1) existing in the first direction when viewed from the conductive films 19 and 21.

In addition, in the film-forming process of the organic semiconductor films 7 and 25 described later, the material constituting the organic semiconductor films 7 and 25 contained as a solute in the solution must remain precipitated in the region between the conductive film 5 and the conductive film 6 in the coating direction (region 8-1 shown in FIGS. 1A and 2) or in the region between the conductive films 19 and 21 and the conductive film 23 in the coating direction (region 30-1 shown in FIGS. 3A and 4). In other words, in this manufacturing process, it is necessary to prevent the solution from being repelled in a direction perpendicular to the direction in which the solution is applied from the regions 6-1 and 30-1, that is, in the second and third directions. Therefore, the conductive film 6 must be formed into a shape that includes a portion (e.g., the second portion 6-2 and the third portion 6-3) that exists in the second and third directions as viewed from the region 8-1, and at least a part of the portion must extend continuously from the portion (e.g., the first portion 6-1) that exists in the first direction. Similarly, the conductive film 23 needs to be formed into a shape that includes portions existing in the second and third directions (e.g., second portion 23-2 and third portion 23-3) when viewed from region 30-1, and at least a portion of the portions extends continuously from a portion existing in the first direction (e.g., first portion 23-1).

Similarly, in the film-forming process of the organic semiconductor films 7 and 25 described later, the material constituting the organic semiconductor films 7 and 25 contained as a solute in the solution must remain to some extent in the region between the conductive film 5 and the conductive film 6 in the direction perpendicular to the application direction (regions 8-2 and 8-3 shown in FIGS. 1A and 2), or in the region between the conductive film 19 and the conductive film 23 in the direction perpendicular to the application direction (region 30-2 shown in FIGS. 3A and 4) and in the region between the conductive film 21 and the conductive film 23 (region 30-3 shown in FIGS. 3A and 4). In other words, in the film-forming process, it is necessary to prevent the solution from being repelled from the regions 6-1, 6-2, 30-1, and 30-2 in the direction in which the solution is applied, that is, in the fourth direction described above. Therefore, the conductive film 6 must be formed in a shape that includes a portion (for example, the fourth portion 6-4 and the fifth portion 6-5) that overlaps with the conductive film 5 in the second and third directions. Similarly, the conductive film 23 needs to be formed in a shape that includes portions (for example, a fourth portion 23-4 and a fifth portion 23-5) that overlap with the conductive films 19 and 21 in the second and third directions.

Although not shown in Figures 1A, 1B, and 2, conductive films 3, 5, and 6 are electrically connected to other circuit elements (transistors, signal lines, power lines, etc.). Similarly, although not shown in Figures 3A, 3B, and 4, conductive films 15, 19, and 21 are electrically connected to other circuit elements. On the other hand, conductive film 23 shown in Figures 3A, 3B, and 4 is not connected to other circuit elements, i.e., is electrically isolated.

(2) Materials A. Substrates 1 and 11
As the substrates 1 and 11, a plastic substrate having low heat resistance such as polyethylene naphthalate (PEN), polyethylene terephthalate (PET) or polypropylene, a plastic substrate having high heat resistance such as polycarbonate, a silicon substrate, a glass substrate, or the like can be used. When a flexible substrate such as a plastic substrate is used as the substrates 1 and 11, it is preferable because the entire semiconductor device can be made flexible. Also, a pulp substrate impregnated with a fluororesin can be used as the substrates 1 and 11.

A. Undercoat films 2 and 13 and insulating films 4 and 17
The undercoat films 2 and 13 and the insulating films 4 and 17 may contain a fluorine-based resin. The undercoat films 2 and 13 and the insulating films 4 and 17 may be made of a fluorine-based resin. The undercoat films 2 and 13 and the insulating films 4 and 17 preferably have smooth surfaces without irregularities. In one embodiment of the present invention, the undercoat films 2 and 13 and the insulating films 4 and 17 must generate photochemically reactive radicals when irradiated with ultraviolet light (details will be described later). For this reason, it is preferable to use a polymer insulating material such as a fluorine-based resin that generates reactive radicals as the undercoat films 2 and 13 and the insulating films 4 and 17.

Examples of such fluororesins include polychlorotrifluoroethylene, polyvinyl fluoride, ethylene-chlorotrifluoroethylene copolymer, polyvinylidene fluoride, perfluoroethylenepropene copolymer, ethylene-tetrafluoroethylene copolymer, polytetrafluoroethylene, and fluororesins having a perfluoroalkoxyalkane or perfluoroalkyl ether ring structure.

Furthermore, it is more preferable to use a perfluororesin, particularly a fluorine-based resin having a perfluoroalkyl ether ring structure, for the base films 2 and 13 and the insulating films 4 and 17. This is because a transistor with excellent characteristics can be obtained. For example, perfluoro(3-butenyl vinyl ether) polymer (CYTOP (registered trademark) manufactured by AGC) or perfluorodimethyldioxole-tetrafluoroethylene copolymer (Teflon (registered trademark) AF) are particularly preferable materials to be applied to the base films 2 and 13 and the insulating films 4 and 17.

Conductive films 3, 5, 6, 15, 19, 21 and 23
The conductive films 3, 5, 6, 15, 19, 21, and 23 may contain a metal or an alloy containing the metal, a conductive organic material, or an organic material in which metal nanoparticles are dispersed. The conductive films 3, 5, 6, 15, 19, 21, and 23 may be made of a metal or an alloy containing the metal, a conductive organic material, or an organic material in which metal nanoparticles are dispersed. Furthermore, the conductive films 5 and 6 shown in Figures 1A and 1B and 2 may be made of the same material. The conductive films 19, 21, and 23 shown in Figures 3A and 3B and 4 may be made of the same material. In this case, the conductive films 5 and 6 or the conductive films 19, 21, and 23 can be formed simultaneously, which is preferable.

Examples of metals or alloys containing the same contained in the conductive films 3, 5, 6, 15, 19, 21, and 23 include metals such as platinum, gold, silver, aluminum, chromium, tungsten, copper, iron, lead, titanium, indium, etc., and alloys containing these metals (such as _InO2 , _ZnO2 , and indium tin oxide (ITO)).

Examples of conductive organic materials contained in the conductive films 3, 5, 6, 15, 19, 21 and 23 include conductive polymer compounds such as polythiophene, polyacetylene, polyparaphenylenevinylene, carbon nanotubes and graphene.

Examples of organic substances in which the metal nanoparticles contained in the conductive films 3, 5, 6, 15, 19, 21 and 23 are dispersed include tetrachloromethane, benzene, dichlorobenzene, dichloromethane, toluene, octane, tetralin, mesitylene, butanol, methanol, etc.

An example of the metal nanoparticles dispersed in the organic material is a metal nanoparticle that contains gold, silver, or copper as a main component and other metal elements. The metal nanoparticles are generally called nano-sized (less than 1 μm), and the average particle size is preferably 10 nm or more and 100 nm or less, more preferably 30 nm or less. In addition, it is preferable that the metal nanoparticles contain gold or silver, since the conductivity of the resulting electrode film is high.

In addition, the proportion of the metal nanoparticles is preferably 30% to 60% by weight based on the total mass of the material. This makes it easier to form the conductive films 3, 5, 6, 15, 19, 21, and 23 into the desired pattern when their thicknesses are set within a suitable range (15 to 100 nm, particularly 30 to 90 nm).

The metal nanoparticles may also be coated with an organic molecular layer containing alkylamines, alkyldiamines, or amines of other structures. This coating is thought to be formed by a large number of alkylamine molecules being bonded to the metal nanoparticles through coordinate bonds of the amino groups, and the alkyl groups of the molecules agglomerating on the surface of the metal nanoparticles. For this reason, the weight ratio of the coating can be adjusted by adjusting the molecular weight of the alkylamine used.

An example of an organic molecular layer containing alkylamines, alkyldiamines, or amines of other structures that coats metal nanoparticles is the following:

First, the medium- or short-chain alkylamine is not particularly limited in structure, but is preferably a primary amino group RNH ₂ (R is a hydrocarbon chain) or a secondary amino group R ₁ R ₂ NH (R ₁ and R ₂ are hydrocarbon chains and may be the same or different). In addition, the medium- or short-chain alkylamine should have a boiling point of 100° C. or higher in consideration of the thermal decomposition temperature of the complex compound, and a boiling point of 250° C. or lower in consideration of the low-temperature sintering property of the coated metal nanoparticles. Examples of the medium- or short-chain alkylamine include, but are not limited to, 2-ethoxyethylamine, dipropylamine, dibutylamine, hexylamine, cyclohexylamine, heptylamine, 3-butoxypropylamine, octylamine, nonylamine, decylamine, 3-aminopropyltriethoxysilane, and dodecylamine.

Examples of long-chain and medium-chain alkylamines include dipropylamine, dibutylamine, hexylamine, cyclohexylamine, heptylamine, 3-butoxypropylamine, octylamine, nonylamine, decylamine, 3-aminopropyltriethoxysilane, dodecylamine, hexadecylamine, oleylamine, and octadecylamine. Any long-chain or medium-chain alkylamine having 6 or more carbon atoms can be used as appropriate depending on the purpose.

Examples of short-chain alkylamines include amylamine, 2-ethoxyethylamine, 4-methoxybutylamine, diisopropylamine, butylamine, diethylamine, propylamine, isopropylamine, ethylamine, and dimethylamine.

The short- or medium-chain alkyldiamine is not particularly limited in structure, but it is preferable that at least one amino group is a primary amino group _RNH2 (R is a hydrocarbon chain) or a secondary _amino group _R1R2NH ( _R1 and _R2 are hydrocarbon chains and may be the same or different). The short- or medium-chain alkyldiamine should have a boiling point of 100°C or higher in consideration of the thermal decomposition temperature of the complex compound, and a boiling point of 250°C or lower in consideration of the low-temperature sintering property of the coated metal nanoparticles. Examples of the diaminodiamine include, but are not limited to, ethylenediamine, N,N-dimethylethylenediamine, N,N'-dimethylethylenediamine, N,N-diethylethylenediamine, N,N'-diethylethylenediamine, 1,3-propanediamine, 2,2-dimethyl-1,3-propanediamine, N,N-dimethyl-1,3-diaminopropane, N,N'-dimethyl-1,3-diaminopropane, N,N-diethyl-1,3-diaminopropane, 1,4-diaminobutane, 1,5-diamino-2-methylpentane, 1,6-diaminohexane, N,N'-dimethyl-1,6-diaminohexane, 1,7-diaminoheptane, and 1,8-diaminooctane.

D. Organic semiconductor films 7 and 25
The organic semiconductor films 7 and 25 may contain one or both of a polymer organic semiconductor material and a low molecular weight organic semiconductor material. In this specification, the term "polymer" refers to a molecule having a molecular weight of more than 10,000, and the term "low molecular weight" refers to a molecule having a molecular weight of 10,000 or less. The organic semiconductor material constituting the organic semiconductor films 7 and 25 is preferably a low molecular weight organic semiconductor material. Furthermore, the molecular weight of the low molecular weight organic semiconductor material is preferably 1500 or less, and more preferably 800 or less. The molecular skeleton of the organic semiconductor material is not particularly limited as long as it has semiconductor performance.

As the low molecular weight organic semiconductor material constituting the organic semiconductor films 7 and 25, a condensed polycyclic aromatic compound is preferred, a condensed polycyclic aromatic compound having an acene skeleton or a heteroacene skeleton is more preferred, a condensed polycyclic aromatic compound having a thienoacene skeleton is particularly preferred, and a compound represented by the following formula (2) or (3) is most preferred. In addition, since the organic semiconductor material is dissolved in an organic solvent when the organic semiconductor films 7 and 25 are formed, it is preferable that the organic semiconductor material is soluble in a solvent. For example, it is preferable that the organic semiconductor material has an alkyl group to ensure solubility. The thienoacene skeleton refers to a compound that contains at least one thiophene ring structure shown in the following formula (1) as a condensed ring site in the molecular structure.

In formula (2), R1 represents an alkyl group. R2 represents an aromatic hydrocarbon group which may have an alkyl group or a heterocyclic group which may have an alkyl group. In formula (3), when R3 and R5 are hydrogen atoms, one of R4 and R6 represents an alkyl group, and the other represents an aromatic hydrocarbon group which may have an alkyl group or a heterocyclic group which may have an alkyl group. In formula (3), when any three of R3 to R6 are hydrogen atoms, the remaining one represents an alkyl group.

These alkyl groups are not limited to straight-chain, branched-chain, or cyclic. For example, examples of these alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl, n-pentyl, n-hexyl, n-octyl, n-decyl, n-dodecyl, and 2-ethylhexyl. As these alkyl groups, straight-chain alkyl groups are preferred, with straight-chain alkyl groups having 4 to 14 carbon atoms being more preferred, straight-chain alkyl groups having 6 to 12 carbon atoms being even more preferred, and straight-chain alkyl groups having 8 to 12 carbon atoms being most preferred.

An aromatic hydrocarbon group which may have an alkyl group means a functional group in which one of the hydrogen atoms on an aromatic hydrocarbon is replaced with an alkyl group, and specific examples thereof include a phenyl group, a naphthyl group, and anthryl group. As the aromatic hydrocarbon group, a phenyl group or a naphthyl group is preferable, and a phenyl group is more preferable.

A heterocyclic group which may have an alkyl group represents a similar embodiment in which the aromatic hydrocarbon group is replaced with a heterocyclic group. Examples of heterocyclic groups include pyridyl, pyrazyl, pyrimidyl, imidazolyl, thienyl, and benzothienyl groups. A preferred heterocyclic group is a thienyl or benzothienyl group.

Examples of polymeric organic semiconductor materials constituting the organic semiconductor films 7 and 25 include polythiophene, polyphenylenevinylene, polyfluorene, polyacetylene, polypyrrole, etc., as well as donor-acceptor type polymers obtained by copolymerizing monomers with high electron density, such as benzodithiophene or thienothiophene, with monomers with low electron density, such as benzothiadiazole, benzobisthiadiazole, or diketopyrrolopyrrole.

Two or more materials may be mixed together to form the organic semiconductor films 7 and 25 in order to improve the characteristics of the semiconductor device or to impart other characteristics. The mixed organic semiconductor material may be either a polymer organic semiconductor material or a low molecular weight organic semiconductor material. In general, the higher the crystallinity of the semiconductor film, the better the characteristics of the thin film transistor. For example, Adv. Mater. 2018.30.1707256 describes that a highly crystalline organic semiconductor film can be obtained by mixing two types of low molecular weight organic semiconductor materials. Therefore, when the organic semiconductor films 7 and 25 are formed using an organic semiconductor material in which two or more materials are mixed, it is preferable that both of the two materials are low molecular weight organic semiconductor materials. Furthermore, it is more preferable that the two materials are low molecular weight organic semiconductors having the same molecular structure and different alkyl group lengths.

These materials may also be dispersed in an organic solvent. That is, the organic semiconductor films 7 and 25 may be made of an organic material in which these materials are dispersed. Furthermore, the organic semiconductor films 7 and 25 may contain additives.

There are no particular limitations on the additives contained in the organic semiconductor films 7 and 25, so long as they do not impair the function of the semiconductor device. For example, examples of such additives include insulating materials, surfactants or thickeners for rheology control, and dopants for carrier injection or for adjusting the carrier amount.

The organic matter that serves as the solvent for these materials can be any material that can dissolve and disperse these materials, but in consideration of storage stability, it is preferable that the solvent be capable of dissolving the materials. Examples of such organic matter include halogen-based solvents such as chloroform, chlorobenzene, and dichlorobenzene, aromatic hydrocarbon solvents such as benzene, toluene, xylene, mesitylene, tetralin, and cyclohexylbenzene, ethers such as tetrahydrofuran, anisole, and phenetole, amides such as dimethylformamide and dimethylacetamide, ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and cyclopentanone, esters such as methyl benzoate and ethyl benzoate, and hydrocarbons such as cyclohexane and decalin.

5A to 5D are diagrams showing an example of a method for manufacturing the semiconductor device shown in Figures 1A, 1B, and 2, and specifically, are diagrams showing the order of film formation from the formation of the undercoat film 2 on the base 1 (Figure 5A) to the formation of the conductive films 5 and 6 (Figure 5D). Note that although Figures 5A to 5D show an example of a method for manufacturing the semiconductor device shown in Figures 1A, 1B, and 2, it is also possible to manufacture the semiconductor device shown in Figures 3A, 3B, and 4 by a similar manufacturing method.

First, a solution containing the material constituting the undercoat film 2 as a solute is applied onto the substrate 1. Methods that can be used to apply the solution include spin coating, dip coating, spray coating, droplet ejection, and die coating. When the undercoat film 2 is applied to the entire upper surface of the flat substrate 1, it is preferable to apply spin coating. The applied solution may then be subjected to a heat treatment at a temperature of 200°C or less, or may be naturally dried. This completes the formation of the undercoat film 2 on the substrate 1 (see FIG. 5A).

Next, ultraviolet light is selectively irradiated onto the base film 2 in the area (first pattern area) where the conductive film 3 will be formed later. The ultraviolet light irradiation method can be a method of irradiating ultraviolet light onto the entire surface of the base film 2 with the area other than the first pattern area covered with a photomask, or a method of irradiating an ultraviolet laser onto only the first pattern area.

As a result, the surface of the undercoat film 2 in the first pattern region becomes a reactive surface through a photochemical reaction. In this specification, the reactive surface refers to a surface in which radical groups are generated on the insulating film surface by a photochemical reaction of an insulating film such as a perfluororesin accompanied by ultraviolet irradiation, and the organic matter in which the metal nanoparticles are dispersed is easily attached and aggregated. In addition, when the metal nanoparticles are covered with an organic molecular layer containing an alkylamine, an alkyldiamine, or an amine of another structure, the radical groups promote the detachment of the organic molecular layer, and the adhesion and aggregation (fusion and aggregation) of the metal nanoparticles to each other is promoted. In this specification, the adhesion and aggregation or fusion and aggregation means a state in which the metal nanoparticles aggregate while adhering (fusing) to the film-forming object.

The ultraviolet light irradiated onto the base film 2 is intended to dissociate the bonds between carbon (C) and fluorine (F) in the base film 2. The bond energy between carbon (C) and fluorine (F) is approximately 490 kJ/mol. Therefore, it is believed that if the wavelength of the ultraviolet light is 244 nm or less, it is possible to dissociate the bonds between carbon (C) and fluorine (F). For example, the wavelength of the ultraviolet light may be 10 nm to 244 nm, preferably 10 nm to 200 nm, and more preferably 100 nm to 200 nm.

Next, a solution containing the material constituting the conductive film 3 as a solute is applied onto the base film 2. A method using an application member such as a blade and a roller can be applied as a method of applying the solution. For example, a method can be applied in which the solution is dropped onto the base film 2 and the solution is applied to the first pattern region of the base film 2 by sweeping a blade close to the base film 2 or rotating a roller. For example, as shown in FIG. 6, the solution 150 is dropped onto the base film 2 and the blade 200 close to the base film 2 is swept from right to left on the paper surface to apply the solution 150 to the first pattern region of the base film 13. The direction in which the blade 200 is swept may be any direction.

As a result, a solution containing the material constituting the conductive film 3 as a solute is applied only to the first pattern region. The applied solution may then be subjected to a heat treatment at a temperature of 200°C or less, or may be allowed to dry naturally. This completes the formation of the conductive film 3 (see FIG. 5B). Note that the disclosure of JP 2014-195794 A may be referenced for the formation of the conductive film 3 on the base film 2.

Next, a solution containing as a solute the material constituting the insulating film 4 is applied onto the base film 2 and the conductive film 3. The method for applying the solution can be the same as the method for applying the solution containing as a solute the material constituting the base film 2, and the above description is therefore incorporated herein. The applied solution may then be subjected to a heat treatment at a temperature of 200°C or less, or may be allowed to dry naturally. This completes the formation of the insulating film 4 (see Figure 5C).

Next, ultraviolet light is selectively irradiated onto the insulating film 4 in the area (second pattern area) where the conductive films 5 and 6 will be formed later. The ultraviolet light irradiation method can be the same as the ultraviolet light irradiation method for the base film 2, so the above explanation is applicable.

Next, a solution containing as a solute the material constituting the conductive films 5 and 6 is applied onto the insulating film 4. The method for applying the solution can be the same as the method for applying the solution containing as a solute the material constituting the conductive film 3, and therefore the above explanation is applicable.

As a result, the solution containing the material constituting the conductive films 5 and 6 as a solute is applied only to the second pattern region. The applied solution may be subjected to a heat treatment at a temperature of 200° C. or less, or may be naturally dried. Furthermore, the conductive films 5 and 6 may be subjected to a surface treatment. One example of the surface treatment is a surface treatment using benzenethiol in which at least one hydrogen atom is substituted with a fluorine atom. As a result, the change in work function between the organic semiconductor film 7 to be formed later and the conductive films 5 and 6 functioning as the source and drain is alleviated, and the carrier injection efficiency is improved. In addition, the surface treatment improves the lyophilicity of the surfaces of the conductive films 5 and 6 with respect to the solvent that is the main component of the solution containing the material constituting the organic semiconductor film 7 as a solute. The formation of the conductive films 5 and 6 is completed as described above (see FIG. 5D). For the formation of the conductive films 5 and 6 on the insulating film 4, the disclosure of JP 2014-195794 A may be referred to.

Next, a solution containing as a solute the material constituting the organic semiconductor film 7 is applied onto the conductive films 5 and 6 and the insulating film 4. The method of applying the solution can be the same as the method of applying the solution containing as a solute the material constituting the conductive films 3, 5, and 6. However, the application of the solution containing as a solute the material constituting the organic semiconductor film 7 is performed along a specific direction.

An example of a method for applying a solution containing, as a solute, the material that constitutes the organic semiconductor film 7 will be described in detail with reference to Figures 7A, 7B to 11A, and 11B. Figures 7A to 11A are top views showing the changes that occur when the solution is applied, and Figures 7B to 11B are cross-sectional views taken along the line C-C' shown in Figures 7A to 11A.

First, a solution 250 containing a material constituting the organic semiconductor film 7 as a solute is dropped onto the insulating film 4 located on the opposite side of the conductive film 6 from the side on which the conductive film 5 is located. Then, as shown in FIGS. 7A and 7B, the blade 300 is placed in a position where it is in contact with the solution 250 and is not in contact with the insulating film 4, etc. It is preferable that the blade 300 has liquid repellency against the solution 250. For example, it is preferable that the surface of the blade 300 is liquid repellent so that it has liquid repellency against the solution 250. An example of liquid repellency treatment for the blade 300 is treatment using perfluoro (3-butenyl vinyl ether) polymer (CYTOP (registered trademark) manufactured by AGC) or perfluorodimethyldioxole-tetrafluoroethylene copolymer (Teflon (registered trademark) AF), which are suitable materials for the insulating film 4. Then, the blade 300 is swept in the direction of the arrow shown in FIG. 7A, that is, from right to left on the paper. In other words, the blade 300 is swept along the fourth direction mentioned above.

When the solution 250 moves toward the conductive film 6 as the blade 300 moves, the solution 250 is positioned on the conductive film 6 as shown in Figures 8A and 8B. Here, since the conductive film 6 has lyophilicity with respect to the solvent that is the main component of the solution 250, the rear end of the solution 250 (the end on the right side of the paper in Figures 8A and 8B) is stretched without following the movement of the blade 300. In addition, drying (volatilization of the solvent) is promoted at the rear end of the solution 250. As a result, the organic semiconductor material, which is the solute of the solution 250, precipitates, and the formation of the organic semiconductor film 7 on the conductive film 6 begins.

9A and 9B, when the blade 300 moves further onto the region between the conductive film 5 and the conductive film 6, the rear part of the solution 250 (the part on the right side of the paper in FIG. 9A and 9B) is stretched by the organic semiconductor film 7 already formed. In addition, because the conductive film 6 having lyophilicity is present behind and to the left and right of the rear part, the rear part is not separated from the organic semiconductor film 7 formed on the conductive film 6, and is also located on the insulating film 4 having lyophobicity. Then, drying (volatilization of the solvent) is promoted in the rear part located on the insulating film 4. As a result, the organic semiconductor material, which is the solute of the solution 250, precipitates, and the organic semiconductor film 7 is also formed on the conductive film 4. Note that, in the insulating film 4 on the opposite side to the side where the conductive film 5 is located as viewed from the conductive film 6, there is no structure for stretching a part of the solution 250, so the drying of the solution 250 is not promoted, and therefore the organic semiconductor film 7 is not formed.

10A and 10B, when the blade 300 is further moved onto the region where the conductive film 6 is not present, the deposition of the organic semiconductor film 7 on the insulating film 4 in the region between the conductive films 5 and 6 proceeds as described above. However, in the region where the lyophilic conductive film 6 is not present on the left and right of the rear portion of the solution 250, the solution 250 is deposited only on the lyophilic conductive film 5, and the solution 250 in the region that does not overlap with the conductive film 5 moves in accordance with the movement of the blade 300.

11A and 11B, when the blade 300 is moved further onto an area where the conductive film 5 is not present, the solution 250 is separated from the organic semiconductor film 7. This completes the formation of the organic semiconductor film 7 (see FIGS. 1A and 1B).

3. Modifications The above-described semiconductor device and manufacturing method thereof are merely examples of the present invention, and semiconductor devices and manufacturing methods thereof having features different from those of the above-described semiconductor device and manufacturing method thereof are also included in the present invention.

For example, the base films 2 and 13 shown in Figures 1B and 3B are not essential components of the present invention. Therefore, a semiconductor device in which the substrate 1, conductive film 3, and insulating film 4 are in contact as shown in Figure 12 is also an aspect of the present invention. The semiconductor device shown in Figure 1B etc. is formed by the above-mentioned manufacturing method, and is therefore preferable in that the conductive film 3 can be patterned with high precision by a relatively simple method. On the other hand, the semiconductor device shown in Figure 12 is preferable in that the process of forming the base film 2 can be eliminated.

In addition, the shape of the conductive film (conductive film 6 shown in Figures 1A and 1B and conductive film 23 shown in Figures 3A and 3B) on which the organic semiconductor film is first formed in the semiconductor device of the present invention is not limited to a U-shape. For example, any of the shapes of conductive films 23' to 23''' shown in Figures 13 to 15 can be used as the shape of the conductive film. Note that although Figures 13 to 15 show a modified example of conductive film 23 shown in Figures 3A and 3B, the shape of conductive film 7 shown in Figures 1A and 1B can also be changed to the shape of conductive films 23' to 23''' shown in Figures 13 to 15.

For example, the conductive film on which the organic semiconductor film is first deposited in the semiconductor device of the present invention may have at least a portion of its top surface curved, as in conductive film 23' shown in Figure 13. Specifically, conductive film 23' is made up of upper and lower portions extending in the directions in which conductive films 19 and 21 extend, i.e., along the first and fourth directions described above, and an intermediate portion extending in a curved manner from the end of the upper portion on the first direction side to the end of the lower portion on the first direction side.

3A and 4, the conductive film 23' includes a first portion 23'-1 located in the first direction as viewed from the conductive films 19 and 21, a second portion 23'-2 located in the second direction and a third portion 23'-3 located in the third direction as viewed from the region between the conductive films 19 and 21 and the first portion 23'-1, a fourth portion 23'-4 located in the fourth direction as viewed from the second portion 23'-2, and a fifth portion 23'-5 located in the fourth direction as viewed from the third portion 23'-3.

The upper portion of the conductive film 23' includes a part of the second portion 23'-2 and the fourth portion 23'-4. The lower portion of the conductive film 23' includes a part of the third portion 23'-3 and the fifth portion 23'-5. The middle portion of the conductive film 23' includes the first portion 23'-1, the remainder of the second portion 23'-2, and the third portion 23'-3.

In addition, the conductive film on which the organic semiconductor film is first deposited in the semiconductor device of the present invention may include a plurality of separated sub-conductive films 23A to 23C, as shown in FIG. 14. Specifically, sub-conductive film 23A includes portion 23''-1 located in the first direction as viewed from conductive films 19 and 21. Sub-conductive film 23B is made up of a portion located in the second direction as viewed from the region between conductive films 19 and 21 and portion 23''-1, and a remainder located in the second direction as viewed from conductive film 19. Sub-conductive film 23C is made up of a portion located in the third direction as viewed from the region between conductive films 19 and 21 and portion 23''-1, and a remainder located in the third direction as viewed from conductive film 21. Furthermore, the sub-conductive film 23A includes a portion located in the second direction when viewed from the end of the sub-conductive film 23B on the first direction side, and a portion located in the third direction when viewed from the end of the sub-conductive film 23C on the first direction side.

3A and 4, the sub-conductive films 23A to 23C shown in FIG. 14 include a first portion 23''-1 located in the first direction as viewed from the conductive films 19 and 21, a second portion 23''-2 located in the second direction and a third portion 23''-3 located in the third direction as viewed from the region between the conductive films 19 and 21 and the first portion 23''-1, a fourth portion 23''-4 located in the fourth direction as viewed from the second portion 23''-2, and a fifth portion 23''-5 located in the fourth direction as viewed from the third portion 23''-3.

Note that the first portion 23''-1 in the sub-conductive films 23A to 23C shown in FIG. 14 includes a portion of the sub-conductive film 23A. Also, the second portion 23''-2 in the sub-conductive films 23A to 23C shown in FIG. 14 includes a portion of the sub-conductive film 23A and a portion of the sub-conductive film 23B. Here, as shown in FIG. 14, the end of the sub-conductive film 23B can extend in the first direction at a position shifted in the third direction (downward in the figure) from the end of the upper side of the sub-conductive film 23A, and it is preferable that there is a region where a portion of the sub-conductive film 23A and a portion of the sub-conductive film 23B overlap in the first direction. Also, the third portion 23''-3 in the sub-conductive films 23A to 23C shown in FIG. 14 includes a portion of the sub-conductive film 23A and a portion of the sub-conductive film 23C. Here, as shown in Fig. 14, the end of sub-conductive film 23C can extend in the first direction at a position shifted in the second direction (upward in the figure) from the end of the lower side of sub-conductive film 23A, and it is preferable that there is a region in which part of sub-conductive film 23A and part of sub-conductive film 23C overlap in the first direction. Moreover, fourth portion 23"-4 in sub-conductive films 23A to 23C shown in Fig. 14 includes a remnant of sub-conductive film 23B. Moreover, fifth portion 23"-5 in sub-conductive films 23A to 23C shown in Fig. 14 includes a remnant of sub-conductive film 23C.

14 shows an example in which the conductive film on which the organic semiconductor film is initially formed is made up of three sub-conductive films 23A to 23C, but the number of sub-conductive films may be two or four or more. In this case, at least one of the first to fifth parts includes at least a portion of each of at least two sub-conductive films among the multiple sub-conductive films.

In addition, the conductive film on which the organic semiconductor film is first formed in the semiconductor device of the present invention may extend such that one end 23'''-6 and the other end 23'''-7 do not overlap with the conductive films 19 and 21 in the second and third directions, as in the conductive film 23''' shown in FIG. 15. The semiconductor device having the conductive film 23 shown in FIG. 4B and the like is preferable in that it can reduce the parasitic capacitance generated in the conductive films 19 and 21 compared to the semiconductor device having the conductive film 23''' shown in FIG. 15. On the other hand, the semiconductor device having the conductive film 23''' shown in FIG. 15 is preferable in that it can reliably form the organic semiconductor film 25 in the region between the conductive film 19 and the conductive film 21, which is the channel formation region of the transistor, compared to the semiconductor device having the conductive film 23 shown in FIG. 4 and the like.

In addition, in the semiconductor device of the present invention, the base film 2 or 13 and the conductive film 3 or 15 may be formed using a known photolithography process. When the base film 2 or 13 and the conductive film 3 or 15 are formed by the above-mentioned film formation method, it is preferable that the conductive film 3 or 15 can be patterned with high precision by a relatively simple method. On the other hand, when a known photolithography process is used, it is preferable that the freedom of material selection is increased, that is, it is possible to select materials suitable for each from a wider range of options.

In addition, in the semiconductor device of the present invention, conductive films 5 and 6 or conductive film 19, films 21 and 23 may be formed in the same process, or may be formed in different processes. Forming them in the same process is preferable in that the film formation process of the semiconductor device can be reduced. On the other hand, forming them in different processes is preferable in that the freedom of material selection is increased.

Manufacture of a semiconductor device including a conductive film having a shape corresponding to the conductive film 23 shown in FIGS. 3A and 3B A semiconductor device including a conductive film having a shape corresponding to the conductive film 23 shown in FIGS. 3A and 3B was manufactured. First, a silicon wafer with a SiO ₂ thermal oxide film (100 nm) was prepared as a substrate, and a CYTOP CTL809M (registered trademark) manufactured by AGC, which serves as an undercoat film, was applied to the substrate by spin coating to a thickness of about 25 nm. Next, gold (Au), which is the material of the conductive film, was deposited by vapor deposition through a shadow mask to a thickness of 25 nm. Next, the surface of the conductive film was exposed to pentafluorobenzenethiol vapor for 20 minutes. Next, the following known organic semiconductor materials No. 1 and No. 2 were dissolved in chlorobenzene to a mass concentration of 0.05%, and then mixed at a volume ratio of No. 1:No. 2=9:1. . Next, the obtained solution was blade-coated on the above-mentioned substrate at a speed of 3.5 μm/sec using a glass blade, and dried at room temperature to produce an organic semiconductor device in which a semiconductor film was formed only in the required areas. The glass blade was coated with CYTOP CTL809M (registered trademark) manufactured by AGC. The thickness of the obtained organic semiconductor film was about 5 nm.

Figure 16 shows a photograph of the semiconductor device obtained by crossed Nicol observation using a polarizing microscope. The area where the crystalline organic semiconductor thin film was formed was determined from the color blinking observed by crossed Nicol observation. No color blinking indicating that an organic semiconductor film had been formed was observed on the CYTOP outside the area shown by the dotted line in the figure, confirming that no organic semiconductor film had been formed. On the other hand, in the area surrounded by the conductive film shown by the dotted line, it was confirmed that a highly crystalline organic semiconductor thin film with multiple crystal orientations had been formed without any defects.

Evaluation of the organic semiconductor device described in Example 1 The organic thin film transistor characteristics of an organic thin film transistor element composed of a source electrode and a drain electrode with a channel width of 800 μm and a channel length of 100 μm included in the semiconductor device manufactured in Example 1 were measured. In this organic thin film transistor element, the thermal oxide film layer SiO ₂ and the undercoat film CYTOP CTL809M (registered trademark) manufactured by AGC Corporation played the role of an insulating film, and the element characteristic value was calculated assuming that the capacitance was 24 nF/cm ^2. The output characteristics of the organic thin film transistor element included in the obtained semiconductor device are shown in FIG. 17. As shown in FIG. 17, the organic thin film transistor element showed linear and saturated output characteristics similar to a typical transistor element. In addition, as shown in FIG. 18, the thin film transistor was capable of low-voltage driving of 2 V or less and had small hysteresis. When the subthreshold swing value indicating that the drain current changes rapidly near the threshold voltage was calculated, the value was 67 mV/dec, indicating extremely steep switching characteristics approaching the theoretical limit. Furthermore, when the carrier mobility of the organic thin film transistor element was calculated, it showed a high mobility of 4.4 cm ² /Vs at maximum.

Manufacture of a semiconductor device including a conductive film having a shape corresponding to the conductive film 23 shown in Figures 1A and 1B A semiconductor device was manufactured by the same method as that described in Example 1, except that the shape of a shadow mask required for forming a conductive film functioning as a source and drain was changed. A polarizing microscope photograph of the obtained semiconductor device is shown in Figure 19. When the location where the organic semiconductor film was formed was confirmed by the same method as that described in Example 1, a crystalline organic semiconductor thin film was obtained only in the area surrounded by the conductive film shown by the dotted line in the figure.

Evaluation of the organic semiconductor device described in Example 3 The organic thin film transistor characteristics of an organic thin film transistor element composed of a source electrode and a drain electrode with a channel width of 300 μm and a channel length of 50 μm included in the semiconductor device manufactured by Example 3 were measured. The insulating film and capacitance in this organic thin film transistor element are the same as the film and value described in Example 2. The output characteristics of the organic thin film transistor element included in the obtained semiconductor device are shown in FIG. 20. As shown in FIG. 20, the organic thin film transistor element showed linear and saturated output characteristics like a typical transistor element. In addition, as shown in FIG. 21, the thin film transistor was capable of low voltage driving of 2 V or less and had small hysteresis. When the subthreshold swing value indicating that the drain current changes rapidly near the threshold voltage was calculated, the value was 75 mV/dec, indicating extremely steep switching characteristics. In addition, when the carrier mobility of the organic thin film transistor element was calculated, it showed a high mobility of up to 1.0 cm ² /Vs.

Variation Evaluation of Organic Semiconductor Device Described in Example 1 Variation in organic thin film transistor characteristics was evaluated for an organic thin film transistor element composed of source and drain electrodes with a channel width of 800 μm and a channel length of 100 μm included in the semiconductor device manufactured in Example 1. The mobility, subthreshold swing (SS) value, and the value and variability of the threshold voltage required to switch the transistor when the drain voltage Vd was set to −0.2 V and −2.0 V are shown in Table 1 below.
[Table 1]

All of the elements measured exhibited high mobility and very steep switching characteristics at an extremely small threshold voltage, and the variation in these characteristics was small. These results demonstrate that the elements obtained by the present invention can be produced with high mobility and steep switching characteristics at low voltages and with excellent yields.

Manufacture of a semiconductor device including a conductive film having a shape corresponding to the conductive film 23 shown in FIG. 3A and FIG. 3B A semiconductor device including a conductive film having a shape corresponding to the conductive film 23 shown in FIG. 3A and FIG. 3B, which has a gate electrode, a source electrode, and a drain electrode formed by a printing process using silver nano-ink, was manufactured by the method described in the publicly known literature (JP 2014195794, Nature Commun. 2016, 7, 11402-1-9). First, a glass substrate was prepared as a base, and CYTOP CTL809M (registered trademark) manufactured by AGC, which serves as a base film, was applied and formed on the base by a spin coating method. Next, after pattern irradiation with VUV light through a photomask, an ink containing silver nanoparticles described in the above publicly known literature (Nature Commun. 2016, 7, 11402-1-9) was used to form a film by the blade coating method described in the publicly known literature, to prepare a gate electrode made of silver nanoparticles. Next, CYTOP CTL809M was applied and formed into a film by a spin coating method in the same manner as above, and then pentafluorobenzenethiol was treated in a gas phase in the same manner as described in Example 1, and a source electrode, a drain electrode, and a guide electrode made of silver nanoparticles were prepared in the same manner as above. The next semiconductor layer was formed by forming a film of the semiconductor material described in Example 1 in the same manner as described in Example 1, and an organic semiconductor device in which a semiconductor film was formed only in a necessary place was manufactured. In order to more clearly observe the film formation state of the semiconductor layer of the organic semiconductor device, a pattern of an organic semiconductor layer was formed in the same manner as above on a substrate on which a CYTOP layer and source and drain electrode layers made of silver nanoparticles were formed in the same manner as above on a silicon substrate with an oxide film, that is, a photograph of the semiconductor device obtained by cross-Nicol observation using a polarizing microscope of the organic semiconductor device in which the semiconductor layer was formed under the same conditions as the semiconductor device is shown in FIG. 22. When the area where the crystalline organic semiconductor thin film was formed was determined from the color blinking observed by crossed Nicol observation, no color blinking indicating that the organic semiconductor film had been formed was observed on the CYTOP outside the area shown by the black dotted line in the figure, and it was confirmed that the organic semiconductor film had not been formed. On the other hand, in the area surrounded by the conductive film shown by the dotted line, it was confirmed that a highly crystalline organic semiconductor thin film with multiple crystal orientations had been formed without any defects.

Evaluation of the organic semiconductor device described in Example 6 The organic thin film transistor characteristics of an organic thin film transistor element composed of a source electrode and a drain electrode with a channel width of 800 μm and a channel length of 200 μm included in the semiconductor device manufactured in Example 6 were measured. In this organic thin film transistor element, the capacitance of the CYTOP CTL809M layer playing the role of an insulating film was calculated based on an experimentally obtained value, and the element characteristic value was calculated as 2.9 nF/cm ^2. The organic thin film transistor element showed a shape of linear and saturated output and transfer characteristics typical of organic field effect transistors without hysteresis, as in the transistor element described in Example 1. When the carrier mobility of the organic thin film transistor element was calculated from the obtained characteristics, it showed a high mobility of up to 2.0 cm ² /Vs under low voltage driving (drain voltage Vd = -0.5 V). In addition, when the subthreshold swing (SS) value indicating that the drain current changes rapidly near the threshold voltage was calculated, the value was 170 mV/dec, indicating extremely steep switching characteristics.

A semiconductor device including a conductive film having a shape corresponding to the conductive film 23 shown in Figures 3A and 3B was manufactured in the same manner as in Example 1, except that the gold electrode, which is the conductive film, was made by silver nanoparticles using the printing process described in Example 7, and the semiconductor solution used for manufacturing the semiconductor layer was changed to a solution in which the following known organic semiconductor materials No. 3 and No. 4 were dissolved in chlorobenzene to a mass concentration of 0.05%, and then mixed at a volume ratio of No. 3:No. 4 = 9:1.

Figure 23 shows a photograph of the semiconductor device obtained by crossed Nicol observation using a polarizing microscope. The area where a crystalline organic semiconductor thin film was formed was determined from the color blinking observed by crossed Nicol observation. No color blinking indicating that an organic semiconductor film had been formed was observed on the CYTOP outside the area shown by the black dotted line in the figure, confirming that no organic semiconductor film had been formed. On the other hand, in the area surrounded by the conductive film shown by the dotted line, it was confirmed that a highly crystalline organic semiconductor thin film with multiple crystal orientations had been formed without any defects.

Evaluation of the organic semiconductor device described in Example 8 The organic thin film transistor characteristics of an organic thin film transistor element composed of a source electrode and a drain electrode with a channel width of 800 μm and a channel length of 80 μm included in the semiconductor device manufactured in Example 8 were measured. In this organic thin film transistor element, the thermal oxide film layer SiO ₂ and the undercoat film CYTOP CTL809M played the role of an insulating film, and the element characteristic value was calculated assuming a capacitance of 2.5 nF/cm ^2. The organic thin film transistor element showed a shape of linear and saturated output and transfer characteristics typical of organic field effect transistors without hysteresis, similar to the transistor element described in Example 1. A total of 15 elements were measured, and the carrier mobility of the organic thin film transistor element was calculated from the obtained characteristics, and showed an average mobility of 0.29 cm ² /Vs at low voltage driving (drain voltage Vd = -5V). In addition, the subthreshold swing (SS) value, which indicates that the drain current changes suddenly near the threshold voltage, was calculated to be 230±40 mV/dec, indicating extremely steep switching characteristics with small variations.

Manufacture of a semiconductor device having only the conductive film 23 shown in Figures 3A and 3B. We verified whether a semiconductor thin film can be formed by film formation by the blade coating method on a substrate having a U-shaped electrode pattern included in a semiconductor device manufactured by the present invention. A base film of CYTOP CTL809M was applied to a silicon substrate with an oxide film by spin coating, and then VUV light was irradiated in a pattern through a photomask. An ink containing silver nanoparticles was then formed by the blade coating method to produce a conductive film made of silver nanoparticles. A semiconductor thin film was formed on this substrate by the same method as that described in Example 8. The results are shown in Figure 24. In the figure, a semiconductor thin film was formed only within the area indicated by the black dotted line, and it was confirmed that a semiconductor can be patterned by the arrangement of the conductive film according to the present invention.

A semiconductor device including a conductive film having a shape corresponding to the conductive film 23 shown in Figures 3A and 3B was manufactured in the same manner as in Example 1, except that the semiconductor solution used to prepare the semiconductor layer was changed to the following known organic semiconductor material No. 5.

Figure 25 shows a photograph of the semiconductor device obtained by crossed Nicol observation using a polarizing microscope. The area where the crystalline organic semiconductor thin film was formed was determined from the color blinking observed by crossed Nicol observation. No color blinking indicating that an organic semiconductor film had been formed was observed on the CYTOP outside the area shown by the black dotted line in the figure, confirming that no organic semiconductor film had been formed. On the other hand, in the area surrounded by the conductive film shown by the dotted line, it was confirmed that a highly crystalline organic semiconductor thin film with multiple crystal orientations had been formed without any defects.

Evaluation of the organic semiconductor device described in Example 11 The organic thin film transistor characteristics of an organic thin film transistor element composed of a source electrode and a drain electrode with a channel width of 800 μm and a channel length of 100 μm included in the semiconductor device manufactured in Example 11 were measured. In this organic thin film transistor element, the thermal oxide film layer SiO ₂ and the undercoat film CYTOP CTL809M played the role of an insulating film, and the element characteristic value was calculated assuming a capacitance of 23 nF/cm ^2. The organic thin film transistor element showed a linear and saturated output and transfer characteristic shape typical of an organic field effect transistor without hysteresis, similar to the transistor element described in Example 1. When the carrier mobility of the organic thin film transistor element was calculated from the obtained characteristics, it showed a maximum mobility of 4.4 cm ² /Vs under low voltage driving (drain voltage Vd = -0.5 V). Furthermore, when the subthreshold swing (SS) value, which indicates that the drain current changes suddenly in the vicinity of the threshold voltage, was calculated, the minimum value was 89 mV/dec, indicating extremely steep switching characteristics.

3A and 3B A semiconductor device including a conductive film having a shape corresponding to the conductive film 23 shown in FIG. 3A and 3B was manufactured in the same manner as in Example 1, except that the semiconductor solution used for producing the semiconductor layer was changed to a solution in which the organic semiconductor material No. 5 described in Example 11 and the known organic semiconductor material No. 6 described below were each dissolved in chlorobenzene to a mass concentration of 0.05%, and then mixed in a volume ratio of No. 5:No. 6=8:2.

Figure 26 shows a photograph of the semiconductor device obtained by crossed Nicol observation using a polarizing microscope. The conductive film pattern in this example is the same as that shown in Figure 16 used in Example 1, and the photograph shown in Figure 25 shows an enlarged view of the source electrode part and the drain electrode part that function as a semiconductor device. When the area where the crystalline organic semiconductor thin film was formed was determined from the color blinking by the crossed Nicol observation, no color blinking indicating that the organic semiconductor film was formed was observed on the CYTOP outside the area shown by the black dotted line in the figure, and it was confirmed that the organic semiconductor film was not formed. On the other hand, it was confirmed that in the area surrounded by the conductive film shown by the dotted line, a highly crystalline organic semiconductor thin film with multiple crystal orientations was formed without any defects.

Evaluation of the organic semiconductor device described in Example 13 The organic thin film transistor characteristics of an organic thin film transistor element composed of a source electrode and a drain electrode with a channel width of 800 μm and a channel length of 200 μm included in the semiconductor device manufactured in Example 13 were measured. In this organic thin film transistor element, the thermal oxide film layer SiO ₂ and the undercoat film CYTOP CTL809M played the role of an insulating film, and the element characteristic value was calculated assuming a capacitance of 23 nF/cm ^2. The organic thin film transistor element showed a linear and saturated output and transfer characteristic shape typical of an organic field effect transistor without hysteresis, similar to the transistor element described in Example 1. When the carrier mobility of the organic thin film transistor element was calculated from the obtained characteristics, it showed a maximum mobility of 0.79 cm ² /Vs under low voltage driving (drain voltage Vd = -0.5 V). Moreover, when the subthreshold swing (SS) value, which indicates that the drain current changes suddenly in the vicinity of the threshold voltage, was calculated, the value was 70 mV/dec, indicating extremely steep switching characteristics.

Manufacture of a semiconductor device including a conductive film having a shape corresponding to the conductive film 23 shown in FIGS. 3A and 3B A semiconductor device including a conductive film having a shape corresponding to the conductive film 23 shown in FIGS. 3A and 3B was manufactured by the same method as that described in Example 1, except that the semiconductor solution used for preparing the semiconductor layer was replaced with a chlorobenzene solution of poly(3-hexyl)thiophene (manufactured by Merck), which is a commercially available organic semiconductor material, and the semiconductor solution was blade-coated at a speed of 5.0 μm/sec. FIG. 27 shows a photograph of the semiconductor device obtained by observation using a microscope. When poly(3-hexyl)thiophene is formed into a thin film on the substrate, it is observed in orange, so that the formed portion can be easily observed. In the figure, it was confirmed that no organic semiconductor film was formed on the CYTOP outside the area indicated by the black dotted line, while poly(3-hexyl)thiophene was formed without any defects in the area surrounded by the conductive film indicated by the dotted line.

Manufacture of a semiconductor device including a conductive film having a shape corresponding to the conductive film 23 shown in FIGS. 3A and 3B In contrast to the method described in Example 1, a silicon wafer with a SiO ₂ thermal oxide film (100 nm) was not coated with CYTOP, but instead, a liquid-repellent treatment was performed by modifying the substrate surface by exposing the substrate to the vapor of 1H,1H,2H,2H,-perfluorodecyltriethoxylane (FAS-17, manufactured by Merck) at 120° C., and a semiconductor solution was blade-coated at a speed of 1.5 μm/sec. A semiconductor device including a conductive film having a shape corresponding to the conductive film 23 shown in FIGS. 3A and 3B was manufactured by the same method as that described in Example 1. A photograph of the semiconductor device obtained by crossed Nicol observation using a polarizing microscope is shown in FIG. 28. The area where a crystalline organic semiconductor thin film was formed was determined from the color blinking observed by the crossed Nicol observation, and it was confirmed that no organic semiconductor film was formed on the CYTOP outside the area shown by the dotted line in the figure. On the other hand, in the area surrounded by the conductive film indicated by the dotted lines, it was confirmed that a highly crystalline organic semiconductor thin film with multiple crystal orientations was deposited without any defects.

Manufacture of a semiconductor device including a conductive film having a shape corresponding to the conductive film 23 shown in FIG. 3A and FIG. 3B A semiconductor device including a conductive film having a shape corresponding to the conductive film 23 shown in FIG. 3A and FIG. 3B was manufactured by the same method as the method described in Example 1, except that the solvent used for preparing the semiconductor solution was changed to o-xylene, the Au electrode was not exposed to PFBT vapor, and the semiconductor solution was blade-coated at a speed of 2.0 μm/sec. FIG. 29 shows a photograph of the semiconductor device obtained by crossed Nicol observation using a polarizing microscope. When the region where a crystalline organic semiconductor thin film was formed was determined from the color blinking by the crossed Nicol observation, no color blinking indicating that an organic semiconductor film was formed was observed on the CYTOP outside the region shown by the dotted line in the figure, and it was confirmed that an organic semiconductor film was not formed. On the other hand, it was confirmed that a highly crystalline organic semiconductor thin film having multiple crystal orientations was formed without any defects in the region surrounded by the conductive film shown by the dotted line.

Evaluation of wettability of conductive film and underlying film of semiconductor film The surface energy of the gold film treated with pentafluorobenzenethiol, which is the conductive film used in Examples 1, 3, 11, 13, 15, and 16, the surface energy of the insulating film layer of CYTOP CTL809M, which is the underlying semiconductor layer used in Examples 1, 3, 6, 7, 9, 11, 13, 15, and 17, the surface energy of the silicon substrate with thermally oxidized film that was surface-treated with FAS-17, which is used in Example 16, and the surface energy of the gold film, which is the conductive film used in Example 17, were evaluated by measuring the contact angle when droplets of water and chlorobenzene were dropped onto the surface. The results are shown in Table 2.
[Table 2]

In the examples, the contact angle values of chlorobenzene and o-xylene, the organic solvents used in the semiconductor solution, were larger on the insulating film surface as the base than on the conductive film in all combinations of conductive film and semiconductor layer base in the examples. The relationship with water contact angle also showed the same results as in the previous period.

Comparative Example 1

Manufacture of a semiconductor device including a conductive film not having a shape corresponding to the conductive film 23 shown in FIGS. 3A and 3B A semiconductor device was manufactured by the same method as that described in Example 1, except that the conductive film was formed so as not to have a shape corresponding to the conductive film 23 shown in FIGS. 3A and 3B and to have only the conductive films 19 and 21 shown in FIGS. 3A and 3B. A photograph of the semiconductor device obtained by crossed Nicol observation using a polarizing microscope is shown in FIG. 30. The area in which a crystalline organic semiconductor thin film was formed was determined from the color blinking by the crossed Nicol observation, and no color blinking indicating that an organic semiconductor film was formed was observed on the CYTOP outside the area shown by the dotted line on the right of FIG. 29. On the other hand, an organic semiconductor thin film was formed only on the conductive film shown by the dotted line. Therefore, an organic semiconductor thin film could not be manufactured in the channel area of a semiconductor device in which one of the conductive films was a source electrode and the other was a drain electrode, and a semiconductor device could not be manufactured.

1, 11: substrate, 2, 13: undercoat film, 3, 15: conductive film, 150: solution, 4, 17: insulating film, 5, 6, 19, 21, 23, 23', 23'": conductive film, 6-1, 23-1, 23'-1, 23"-1: first part, 6-2, 23-2, 23'-2, 23"-2: second part, 6-3, 23-3, 23'-3, 23"-3: third part Part, 6-4, 23-4, 23'-4, 23"-4: fourth part, 6-5, 23-5, 23'-5, 23"-5: fifth part, 23A to 23C: sub-conductive film, 23'"-6: one end, 23'"-7: other end, 7, 25: organic semiconductor film, 8-1 to 8-3, 30-1 to 30-3: region, 200, 300: blade, 250: solution

Claims (17)

A first conductive film;
an insulating film on the first conductive film;
a second conductive film and a third conductive film on the insulating film;
an organic semiconductor film on the insulating film, the second conductive film, and the third conductive film;
the second conductive film includes a portion extending along a first direction,
The third conductive film is
a first portion located in the first direction as viewed from the second conductive film;
a second portion located in a second direction perpendicular to the first direction when viewed from a region between the second conductive film and the first portion, and a third portion located in a third direction opposite to the second direction;
a fourth portion located in a fourth direction opposite to the first direction as viewed from the second portion;
a fifth portion located in the fourth direction as viewed from the third portion,
the first portion, at least a portion of the second portion, and at least a portion of the third portion extend continuously;
a surface free energy of the insulating film is smaller than a surface free energy of the second conductive film and a surface free energy of the third conductive film,
a fourth conductive film on the insulating film, the fourth conductive film including a portion extending substantially parallel to the second conductive film and positioned between the fourth portion and the fifth portion;
The first conductive film functions as a gate;
the second conductive film functions as one of a source and a drain;
the fourth conductive film functions as the other of the source and drain;
Semiconductor device. The third conductive film is
an upper portion extending along the first direction and the fourth direction and including the second portion and the fourth portion;
a lower portion extending along the first direction and the fourth direction and including the third portion and the fifth portion;
an intermediate portion extending along the second direction and the third direction and including the first portion;
2. The semiconductor device according to claim 1, wherein an end of the upper portion on the first direction side is continuous with an end of the middle portion on the second direction side, and an end of the lower portion on the first direction side is continuous with an end of the middle portion on the third direction side. The third conductive film is
an upper portion extending along the first direction and the fourth direction and including a part of the second portion and the fourth portion;
a lower portion extending along the first direction and the fourth direction and including a part of the third portion and the fifth portion;
2. The semiconductor device according to claim 1, further comprising: a central portion that extends in a curved manner from an end of the upper portion on the first direction side to an end of the lower portion on the first direction side, and that includes the first portion, a remainder of the second portion, and a remainder of the third portion. The semiconductor device according to claim 1 , wherein the second conductive film and the third conductive film are made of the same material. The semiconductor device according to claim 1 , wherein said second conductive film, said third conductive film and said fourth conductive film are made of the same material. The semiconductor device according to claim 1 , wherein the insulating film contains a fluorine-based resin. 6. The semiconductor device according to claim 1 , wherein the insulating film contains a perfluoro(3-butenyl vinyl ether) polymer. The semiconductor device according to claim 1 , wherein the organic semiconductor film contains a polymer organic semiconductor material or a small molecule organic semiconductor material. The semiconductor device according to claim 8 , wherein the small molecule organic semiconductor material is a compound having an acene skeleton or a heteroacene skeleton. a base film below the first conductive film;
The semiconductor device according to claim 1 , further comprising a base body below the undercoat film. The semiconductor device according to claim 10 , wherein the undercoat film contains a fluorine-based resin. The semiconductor device according to claim 10 , wherein the undercoat film contains perfluoro(3-butenyl vinyl ether) polymer. The semiconductor device according to claim 10 , wherein the base is flexible . forming a first conductive film;
forming an insulating film on the first conductive film;
irradiating the first region and the second region of the insulating film with ultraviolet light;
forming a second conductive film and a third conductive film in the first region and the second region, respectively;
forming an organic semiconductor film on the insulating film, the second conductive film, and the third conductive film;
The first region extends along a first direction,
The second region is
A first portion located in the first direction as viewed from the first region;
a second portion located in a second direction perpendicular to the first direction when viewed from a region between the first region and the first portion, and a third portion located in a third direction opposite to the second direction;
a fourth portion located in a fourth direction opposite to the first direction as viewed from the second portion;
a fifth portion located in the fourth direction as viewed from the third portion,
the first portion, at least a portion of the second portion, and at least a portion of the third portion extend continuously;
a contact angle of a solvent , which is a main component of a solution containing a material constituting the organic semiconductor film as a solute, with respect to the insulating film is larger than a contact angle of the solvent with respect to each of the second conductive film and the third conductive film;
The method for manufacturing a semiconductor device, wherein the step of forming the organic semiconductor film includes a step of applying the solution along the fourth direction. forming a first conductive film;
forming an insulating film on the first conductive film;
irradiating a first region, a second region, and a third region of the insulating film with ultraviolet light;
forming a second conductive film, a third conductive film, and a fourth conductive film in the first region, the second region, and the third region, respectively;
forming an organic semiconductor film on the insulating film, the second conductive film, the third conductive film, and the fourth conductive film;
The first region and the third region extend substantially parallel to each other along a first direction,
The second region is
a first portion located in the first direction as viewed from the first region and the third region;
a second portion located in a second direction perpendicular to the first direction when viewed from the first region and a region between the third region and the first portion, and a third portion located in a third direction opposite to the second direction;
a fourth portion located in a fourth direction opposite to the first direction as viewed from the second portion;
a fifth portion located in the fourth direction as viewed from the third portion,
the first portion, at least a portion of the second portion, and at least a portion of the third portion extend continuously;
a contact angle of a solvent, which is a main component of a solution containing a material constituting the organic semiconductor film as a solute, with respect to the insulating film is larger than contact angles of the solvent with respect to each of the second conductive film, the third conductive film, and the fourth conductive film;
The method for manufacturing a semiconductor device, wherein the step of forming the organic semiconductor film includes a step of applying the solution along the fourth direction. The coating step includes:
dropping the solution onto the insulating film;
The method for manufacturing a semiconductor device according to claim 14 or 15 , further comprising the step of sweeping the solution along the fourth direction with a coating member. The method for manufacturing a semiconductor device according to claim 16 , further comprising the step of subjecting a surface of the coating member to a liquid-repellent treatment so as to impart liquid repellency to the solvent, prior to the step of forming the organic semiconductor film.