JP6459385B2 - Semiconductor element and semiconductor device - Google Patents

Description

  The present invention relates to a semiconductor element using a plurality of carbon nanotubes as a current path, and a semiconductor device using the semiconductor element.

  Thin film transistors (TFTs) are widely used as pixel switching elements for display devices such as liquid crystal displays and EL displays (Electro-Luminescence displays). Such TFTs were made on glass substrates using amorphous or polycrystalline silicon. However, CVD equipment (Chemical Vapor Deposition equipment) used to create TFTs using silicon is very expensive, and the increase in area of display devices using TFTs is accompanied by a significant increase in manufacturing costs. It was. In addition, since the process of forming amorphous or polycrystalline silicon is performed at an extremely high temperature, there are limitations on materials that can be used as a substrate, and a lightweight resin substrate cannot be used.

  A carbon nanotube (CNT: Carbon NanoTube) is a cylindrical carbon molecule made of only carbon, and has a structure in which a graphene sheet composed of a six-membered ring of carbon atoms is wound. A CNT formed by rolling a single graphene sheet into a cylinder is called a single-walled nanotube (SWNT). A CNT in which a multilayer graphene sheet is formed into a cylindrical shape is called a multi-wall nanotube (MWNT). The diameter of SWNT is about 1 nm, and MWNT is about several tens of nm. In SWNT, there are various types of carbon nanotubes having different degrees of spiralness (chirality) depending on the direction in which the graphene sheet is rolled, that is, the orientation of the six-membered ring of carbon atoms with respect to the circumferential direction. Examples of various carbon nanotubes having different spiral degrees (chirality) include helical carbon nanotubes, zigzag carbon nanotubes, and armchair carbon nanotubes. In SWNT, both metallic and semiconducting properties appear due to the difference in spirality (chirality).

  A field effect transistor having a channel layer made of SWNTs can be produced by growing SWNTs having the above-described characteristics randomly between source / drain electrodes by, for example, chemical vapor deposition (CVD). The channel layer made of SWNT can also be formed by dispersing SWNT in a liquid, coating, depositing, and printing on a substrate.

  Non-Patent Document 1 reports that in the SWNT random network formed in this way, many contacts are formed and connections between carbon nanotubes occur, and can be used for a channel layer of a thin film transistor. .

According to Non-Patent Document 1, when the density of single-walled carbon nanotubes in the channel layer is about 1 / μm ² , a 5-digit on / off ratio and a mobility of 7 cm ² / Vs can be obtained, and a good thin film transistor Has been realized. As described above, the SWNT random network can be formed by applying a SWNT dispersion or printing a SWNT dispersion. In this process, an increase in area can be realized at low cost, the process temperature is low, and there are few restrictions when selecting a material used as a substrate. Therefore, it is possible to significantly reduce the manufacturing cost as compared with the conventional silicon TFT formed on the glass substrate. In recent years, TFT using a random network of SWNT has been actively reported, and there are many reports.

E. S. Snow et al., Applied Physics Letters, Vol.82, No.13, pp.2145-2147, (2003)

  However, the semiconductor device of the background art described above has the following problems.

  A TFT using SWNT as a channel generally exhibits p-type TFT characteristics. Depending on the conditions of SWNT synthesis, purification, dispersion treatment, channel formation conditions, gas adsorption on the surface of SWNT, SWNT is excessively doped, and as a result, p-type characteristics may become too strong.

  At this time, the threshold voltage of the gate where the TFT is turned on is greatly shifted to a positive voltage. As a result, even if the TFT gate voltage is set to 0 V, current continues to flow between the source and drain electrodes, and the practical on / off ratio of the TFT is significantly reduced. In order to completely turn off the TFT, it is necessary to continuously apply a positive voltage to the gate electrode. This situation is not desirable from the viewpoint of power consumption. Furthermore, continuing to apply a voltage to the gate electrode induces electrostatic breakdown of the gate insulating film of the TFT and significantly reduces the device life. Such a problem is caused by the fact that it is extremely difficult to control the carrier concentration of TFT using SWNT as a channel.

  An object of the present invention is to practically improve the electrical characteristics of a TFT using a SWNT random network as a current path. In particular, the present invention provides a TFT capable of controlling a carrier concentration, adjusting a threshold voltage of a semiconductor element, and improving a practical on / off ratio. It is another object of the present invention to provide a semiconductor device including a semiconductor element having a current path of a random SWNT network with improved electrical characteristics as a current path.

  In order to achieve the above object, a semiconductor device according to the present invention includes a current path composed of a plurality of carbon nanotubes, two electrodes that are in electrical contact with each other through the current path, and a part of the current path. Or the pigment | dye and resin mixture layer provided so that it might contact | connect all the area | regions was provided.

  The semiconductor device according to the present invention is in contact with a current path composed of a plurality of carbon nanotubes, two electrodes in electrical contact with each other through the current path, and a part or all of the current path. A plurality of semiconductor elements each provided with a mixture layer of a provided pigment and resin are provided.

  According to the present invention, the threshold voltage of a semiconductor element having a plurality of carbon nanotubes as channels can be adjusted.

1 is a schematic cross-sectional view of a semiconductor element having a random network channel of SWNT and a dye-containing resin layer according to a first embodiment of the present invention. It is an example of the pigment | dye used for embodiment and an Example of this invention, and its molecular structure. 4 is a graph showing an example of electrical characteristics of the semiconductor device according to the first embodiment of the present invention. It is a graph which shows another example of the electrical property of the semiconductor element by 1st Embodiment of this invention. It is a graph which shows another example of the electrical property of the semiconductor element by 1st Embodiment of this invention. It is a graph which shows another example of the electrical property of the semiconductor element by 1st Embodiment of this invention. It is the light absorption characteristic of the typical pigment | dye used for this invention. (A) is sectional drawing of the semiconductor element of background art, (b) is a graph which shows the electrical property of the semiconductor element of background art. It is a schematic cross section of a semiconductor device according to a second embodiment of the present invention. It is a schematic cross section of a semiconductor device according to a third embodiment of the present invention. It is a schematic cross section of the semiconductor element by 4th Embodiment of this invention. It is a schematic cross section of a semiconductor device according to a fifth embodiment of the present invention. It is a schematic cross section of the semiconductor element by 6th Embodiment of this invention. It is a schematic cross section of the semiconductor device by 7th Embodiment of this invention. It is a schematic circuit diagram which shows the circuit structure to which the semiconductor device by 7th Embodiment of this invention is applied. It is a schematic circuit diagram which shows an example of the basic cell of the circuit structure of FIG. 11B.

  The present invention relates to a semiconductor element in which a current path between two electrodes is controlled, and a semiconductor device using the same. The current path of the semiconductor element is composed of a plurality of carbon nanotubes. The present invention is particularly characterized by comprising a mixture layer of a dye and a resin provided so as to be in contact with a part or all of the region of the current path. Hereinafter, the semiconductor element and the semiconductor device of the present invention will be described more specifically as embodiments and examples.

[First Embodiment]
First, the semiconductor device according to the first embodiment of the present invention will be described.

  FIG. 1 is a cross-sectional view showing an example of a structure of a field effect transistor using a random network of CNTs of the present invention as a channel layer. This embodiment shows an example in which the present invention is applied to a bottom-gate type field effect transistor.

  The semiconductor element of this embodiment includes a gate electrode 12 formed on a film substrate 11 as an example of a support substrate, and a gate insulating film 13 formed so as to cover the gate electrode 12. Furthermore, the semiconductor device of this embodiment includes a source electrode 14 and a drain electrode 15 disposed on the gate insulating film 13 with a distance corresponding to the channel length. Furthermore, the semiconductor element of this embodiment is an example of a channel formed of a plurality of carbon nanotubes so as to be electrically connected between the source electrode 14 and the drain electrode 15 formed on the gate insulating film 13 above the gate electrode 12. SWNT channel 16 is provided. Furthermore, the semiconductor element of this embodiment is provided with a dye-containing resin layer 17 containing a dye so as to be in contact with and cover the SWNT channel 16. In the semiconductor element of FIG. 1, the dye-containing resin layer 17 is formed so as to cover the SWNT channel 16 and also cover a part of the drain electrode 15 and the source electrode 14.

  As the dye-containing resin layer 17, for example, an acrylic resin containing phthalocyanine is conceivable.

  Phthalocyanine is a compound having a cyclic structure in which four phthalimides are crosslinked with nitrogen atoms. Various elements such as transition metals are bonded to the central part to form a stable complex. Phthalocyanine and its complex have a strong color with π electrons spreading throughout the molecule. Phthalocyanine and its complexes have been used as standard pigments because of their robust molecules and high light resistance. Specifically, copper phthalocyanine (PB15: Pigment Blue 15), metal-free phthalocyanine (PB16: Pigment Blue 16), highly chlorinated copper phthalocyanine (PG7: Pigment Green 7), brominated chlorinated copper phthalocyanine (PG36: Pigment Green) 36).

  FIG. 2A to FIG. 2D show examples of the molecular structure of phthalocyanine used in the embodiments and examples of the present invention. 2A shows copper phthalocyanine, FIG. 2B shows metal-free phthalocyanine, FIG. 2C shows brominated chlorinated copper phthalocyanine, and FIG. 2D shows highly chlorinated copper phthalocyanine.

  As shown in FIG. 4, the phthalocyanine dye has mainly two light absorption bands called a Q band near a wavelength of 600 to 700 nm and a Soret band of 400 nm or less. By changing the central metal or the modifying group, the electronic state of the molecule and the light absorption wavelength are changed, and the hue as a dye can be changed.

  In addition, in the phthalocyanine dye, π-π interaction spreads between molecules due to π electrons spreading throughout the molecule, and it is easy to form a crystal in which planar molecules are stacked and easily aggregate. For this reason, it is generally mixed and dispersed with resin or the like. In particular, those dispersed in a water-soluble acrylic resin are generally commercially available as acrylic paints.

  On the other hand, SWNT is a rolled graphene sheet with π electrons spreading on the surface. Since the surface has a curvature, π electrons ooze out and easily interact with external π electrons. Therefore, when a phthalocyanine-based dye approaches the SWNT, it is bound by π-π interaction, and the electronic state of SWNT can be changed. In the semiconductor element of this embodiment, the dye-containing resin layer 17 is provided so as to be in contact with and cover the SWNT channel 16. Thereby, it couple | bonds by (pi) -pi interaction and the electronic state of SWNT channel 16 changes.

  In this way, the electronic state of SWNT can be controlled by changing the frequency (dye concentration) of the phthalocyanine dye, the type of the central metal of phthalocyanine, and the type of the modifying group. As a result, it is possible to obtain a semiconductor element having desired electrical characteristics and using a random network of SWNTs as a current path.

  Specific manufacturing methods and electrical characteristics of the semiconductor element of the present embodiment will be described in detail in the following (Examples).

[Second Embodiment]
Next, a semiconductor device according to a second embodiment of the present invention will be described. FIG. 6 is a sectional view showing a semiconductor device according to the second embodiment of the present invention. In the semiconductor element of this embodiment, the semiconductor element of the first embodiment further includes a silica layer.

  Similar to the semiconductor device of the first embodiment, the semiconductor device of this embodiment includes a gate electrode 32 formed on a film substrate 31 as an example of a support substrate, and a gate insulation formed so as to cover the gate electrode 32. And a film 33. Furthermore, the semiconductor element of this embodiment includes a thin silica layer 38 formed so as to cover the gate insulating film 33. Furthermore, the semiconductor device of this embodiment includes a source electrode 34 and a drain electrode 35 disposed on the silica layer 38 with a distance corresponding to the channel length. Furthermore, the semiconductor element of this embodiment is an example of a channel formed of a plurality of carbon nanotubes so as to be electrically connected between the source electrode 34 and the drain electrode 35 formed on the silica layer 38 above the gate electrode 32. A SWNT channel 36 is provided. Furthermore, the semiconductor element of this embodiment is provided with a dye-containing resin layer 37 containing a dye so as to be in contact with and cover the SWNT channel 36. In the semiconductor element of FIG. 6, the dye-containing resin layer 37 is formed so as to cover the SWNT channel 36 and to cover part of the source electrode 34 and the drain electrode 35.

  In the semiconductor element of the present embodiment, as in the semiconductor element of the first embodiment, the dye in the dye-containing resin layer 37 and the π electrons of the SWNT channel 36 interact, and the electronic state of the SWNT channel 36 changes. Thereby, the same effect as the semiconductor device of the first embodiment can be obtained.

  Further, in the semiconductor element of this embodiment, a thin silica layer 38 is provided between the gate insulating film 33 and the SWNT channel 36. The thin silica layer 38 was formed by spin-coating hydrogen silsesquioxane diluted with methyl isobutyl ketone (MIBK) and baking at 180 ° C. Further, before the SWNT channel 36 was formed by printing, the upper surface of the thin silica layer 38 was modified with an amino group by treating with an aqueous 3-aminopropyltriethoxysilane solution. The SWNT channel 36 is more adsorbed to the amino group, thereby improving the uniformity of the SWNT channel 36. As a result, according to the present embodiment, in addition to the same effects as those of the first embodiment, the uniformity of the element characteristics and the controllability of the carrier concentration by the dye-containing resin layer 37 can be improved.

[Third Embodiment]
In the semiconductor elements of the first and second embodiments of the present invention, the effect when the dye-containing resin layer is provided on the SWNT channel has been described. The essence of the present invention is to control the carrier concentration of the SWNT channel by the interaction between the dye and the π electron of the SWNT channel. Therefore, the effect is the same even if the dye-containing resin layer is in contact with the SWNT channel and is provided under the SWNT channel.

  Next, the semiconductor element of 3rd Embodiment of this invention is demonstrated. FIG. 7 is a sectional view showing a semiconductor device according to the third embodiment of the present invention. Similarly to the semiconductor elements of the first and second embodiments, the semiconductor element of the present embodiment covers the gate electrode 42 formed on the film substrate 41 as an example of the support substrate and the gate electrode 42. And a formed gate insulating film 43. Furthermore, the semiconductor element of this embodiment includes a dye-containing resin layer 47 provided so as to be stacked on the gate insulating film 43. Furthermore, the semiconductor element of this embodiment includes a source electrode 44 and a drain electrode 45 arranged on the dye-containing resin layer 47 with a distance corresponding to the channel length. Furthermore, a SWNT channel 46 as an example of a channel formed of a plurality of carbon nanotubes is formed on the dye-containing resin layer 47 above the gate electrode 42 so as to electrically connect the source electrode 44 and the drain electrode 45. Prepare. In the device structure shown in FIG. 7, the dye-containing resin layer 47 is provided so as to be stacked on the gate insulating film 43. The SWNT channel 46 is disposed so as to be in contact with the dye-containing resin layer 47, and the function of adjusting the carrier concentration is the same as that of the first and second embodiments.

[Fourth Embodiment]
A semiconductor element in which the dye-containing resin layer is in contact with the SWNT channel and provided under the SWNT channel in a manner different from that of the third embodiment will be described as a semiconductor element of the fourth embodiment of the present invention.

  FIG. 8 is a sectional view showing a semiconductor device according to the fourth embodiment of the present invention. In the device structure shown in FIG. 8, the gate insulating film contains a dye, and the gate insulating film is a dye-containing gate insulating film 53. The semiconductor element of this embodiment includes a gate electrode 52 formed on a film substrate 51 as an example of a support substrate, and a gate insulating film formed so as to cover the gate electrode 52. The gate insulating film of this embodiment is a dye-containing gate insulating film 53. Furthermore, the semiconductor element of this embodiment includes a source electrode 54 and a drain electrode 55 disposed on the dye-containing gate insulating film 53 with a distance corresponding to the channel length. Further, a SWNT channel 56 as an example of a channel formed of a plurality of carbon nanotubes is formed on the dye-containing gate insulating film 53 above the gate electrode 52 so as to electrically connect the source electrode 54 and the drain electrode 55. Is provided.

  The dye-containing gate insulating film 53 of the present embodiment is formed by spin-coating an insulator made of an organic polymer containing phthalocyanine on the film substrate 51 so as to cover the gate electrode 52 and then baking. The dye-containing gate insulating film 53 thus formed is made of a dye-containing resin.

  In the semiconductor element of the present embodiment, the dye in the dye-containing gate insulating film 53 and the π electrons of the SWNT channel 56 interact, and the electronic state of the SWNT channel 56 changes. As a result, the same effects as those of the semiconductor elements of the first to third embodiments can be obtained.

  Furthermore, in the semiconductor element of the present embodiment, the number of layers constituting the device can be reduced as compared with the device structure shown in FIG. Further, in the device structure of FIG. 8, the upper surface of the SWNT channel is vacant. Therefore, when a stronger carrier concentration adjustment is required, such as when a thick SWNT channel is used, a dye-containing resin layer can be provided on the upper surface of the SWNT channel.

[Fifth Embodiment]
The present invention can be applied not only to the bottom gate type thin film transistor described as the first to fourth embodiments but also to a top gate type thin film transistor. An example applied to a top gate type thin film transistor will be described as a semiconductor device according to a fifth embodiment of the present invention.

  FIG. 9 is a sectional view showing a semiconductor device according to the fifth embodiment of the present invention. A dye-containing resin layer 67 is laminated on a film substrate 61 as an example of a support substrate, and a channel 66 composed of a plurality of SWNTs is formed. A source electrode 64 and a drain electrode 65 are arranged so as to obtain electrical contact with the SWNT channel 66. A gate insulating film 63 is formed so as to cover part of the source electrode 64 and drain electrode 65 and the SWNT channel 66. The surface of the gate insulating film 63 is undulated according to the height of the electrode, and a recess is formed at a portion facing the SWNT channel 66. A gate electrode 62 is formed in the recessed portion by utilizing the fluidity of the ink.

  Even in such a device structure, the SWNT channel 66 and the dye-containing resin layer 67 are in contact with each other, and the carrier concentration adjustment / control according to the present invention functions effectively. Further, by adopting such a device structure, the positional relationship between the source electrode 64 / drain electrode 65 and the gate electrode 62 is determined in a self-aligned manner, so that the parasitic capacitance of the device is lowered and the element performance is reduced. Monthly can be improved. Moreover, since the SWNT channel 66 can be formed on a smoother surface, the uniformity and reproducibility of device characteristics can be improved. Further, it is not necessary to prepare a specific mask, plate, pattern data, etc. for forming the dye-containing resin layer 67, and the cost burden during manufacturing is small.

[Sixth Embodiment]
The main object of the present invention is to suppress the excess carriers and improve the TFT off characteristics by utilizing the interaction between the dye and the π electron of the SWNT of the channel. However, when the carrier concentration is lowered, the apparent on-characteristic is lowered. From the viewpoint of improving TFT off characteristics, SWNTs and dyes in the entire channel interact with each other, and it is not necessary to adjust the carrier concentration, and only a part of the channel is sufficient.

  As a sixth embodiment of the present invention, a modification of the semiconductor device of the first embodiment is shown. FIG. 10 is a cross-sectional view showing an example of a structure of a field effect transistor using a random network of CNTs of the present invention as a channel layer. Similar to the first embodiment, the semiconductor device of this embodiment includes a film substrate 71, a gate electrode 72, a gate insulating film 73, a source electrode 74 and a drain electrode 75, and a SWNT channel 76. In the example of the device structure shown in FIG. 10, the dye-containing resin layer 77 is disposed so as to contact only a part of the SWNT channel 76. In other words, in the semiconductor element of this embodiment, the dye-containing resin layer 77 is formed so as to cover only a part of the SWNT channel 76.

  In the portion of the SWNT channel 76 where the dye-containing resin layer 77 is in contact, excessive carriers are suppressed by interacting with the dye, and off characteristics are secured. In the portion of the SWNT channel 76 where the dye-containing resin layer 77 is not in contact, there is no interaction with the dye, and excess carriers are present. Excess carriers are effective in reducing channel resistance and reducing the Schottky barrier generated between the source electrode 74 and drain electrode 75 and the SWNT channel 76. As a result, the on-characteristics of the TFT are improved. The device structure shown in FIG. 10 can provide a TFT having excellent off characteristics and on characteristics.

  In the embodiment of the present invention, it is possible to maintain the shape of the dye-containing resin layer 77 shown in FIG. 10 by mixing a dye that interacts with SWNTs in advance with a resin, and has practically sufficient adhesion. Is obtained.

[Seventh Embodiment]
Next, an example of a semiconductor device manufactured using a plurality of semiconductor elements of the present invention will be described as a seventh embodiment of the present invention. This embodiment shows the case where it applies to an array sensor. Unit cells are arranged in a matrix to constitute an array sensor that detects contact and pressure. FIG. 11A is a cross-sectional view showing the device structure of the semiconductor device of this embodiment. FIG. 11B is a circuit diagram showing a circuit configuration to which the semiconductor device of this embodiment is applied. FIG. 11C is a circuit diagram showing a unit cell having the circuit configuration of FIG. 11B.

  FIG. 11A shows a circuit configuration composed of two thin film transistors, but a configuration in which a large number of unit cells are arranged as shown in FIG. 11B.

  The semiconductor device illustrated in FIG. 11A includes a plurality of gate electrodes 82 formed on a film substrate 81 as an example of a support substrate. The gate electrode 82 is electrically connected to one of the word lines 91 (WL1 to WL4,...) Shown in FIG. 11B. Further, the semiconductor device includes a gate insulating film 83 formed so as to cover the plurality of gate electrodes 82 and a plurality of source electrodes 84 and drain electrodes 85 arranged on the gate insulating film 83 with a distance corresponding to the channel length. And a pair.

  Furthermore, the semiconductor device of this embodiment is an example of a channel formed of a plurality of carbon nanotubes so as to be electrically connected between the source electrode 84 and the drain electrode 85 formed on the gate insulating film 83 above the gate electrode 82. SWNT channel 86 is provided. The drain electrode 85 is electrically connected to one of the bit lines 92 (BL1 to BL4,...) Shown in FIG. 11B. The source electrode 84 is electrically connected to the element pad 93 shown in FIG. 11B.

  A plurality of SWNT channels 86 composed of a plurality of carbon nanotubes are arranged on the gate insulating layer 83 so as to face the gate electrode 82 and to be electrically connected to the source electrode 84 and the drain electrode 85. ing.

  Further, a dye-containing resin layer 87 containing a dye is provided so as to contact the SWNT channel 86. The dye-containing resin layer 87 is formed so as to cover an element region other than the element pad 93 and the peripheral pad 94. The word line 91 is connected to the word selector / driver circuit via the peripheral pad 94. The bit line 92 is connected to the bit selector / driver circuit via the peripheral pad 94. Further, a pressure-sensitive conductive rubber sheet 88 and a metal foil 89 are laminated and electrically connected via an element pad 93.

  The pressure-sensitive conductive rubber sheet 88 corresponds to the variable resistance 96 of the unit cell (FIG. 11C), and has a property that the resistance in the vertical direction changes due to elastic deformation of the rubber. The metal foil 89 corresponds to the ground 95 of the unit cell (FIG. 11C). As shown in FIG. 11A, the pressure-sensitive conductive rubber sheet 88 is formed so as to planarly overlap with a plurality of thin film transistors, and constitutes a common ground 95 of the unit cells of FIG. 11C.

  In this example, the dye-containing resin layer 87 is an interlayer insulating film for adjusting the carrier concentration of the SWNT channel 86 and preventing the drain electrode 85, the word line 91, the SWNT channel 86 and the like from being short-circuited with the metal foil 89. It has the function of

  According to the semiconductor device of this embodiment, a layer having a function of adjusting the carrier concentration and interlayer insulation can be formed at the same time, and the cost load during manufacturing is small.

  The present invention is not limited to a pressure-sensitive conductive rubber sheet, and is effective for integration of all functional elements that are used by applying a current / voltage in the vertical direction, such as electrophoretic ferroelectric microcapsules used in display elements. It is clear. Further, when integrating functional elements to be used by applying current / voltage in the planar direction, the dye-containing resin layer 87 can be provided in all regions except the peripheral pads. In that case, the dye-containing resin layer 87 can have a function as a passivation film that protects the semiconductor device from friction and the surrounding environment, and is highly effective from the viewpoint of device life.

  Next, electrical characteristics of the semiconductor device according to the embodiment of the present invention will be described.

  First, a background art semiconductor device will be described as a comparison object with the present invention. FIG. 5A is a cross-sectional view showing a device structure of a semiconductor element of the background art, and FIG. 5B is a graph showing electric characteristics of the semiconductor element of FIG. In the semiconductor element of the background art, a gate electrode 22 is formed on a support substrate 21 and a gate insulating film 23 is further laminated. A source electrode 24 and a drain electrode 25 are disposed on the gate insulating film 23, and a SWNT channel 26 is electrically connected.

  The gate voltage is changed from -40V to + 40V with a drain voltage of -2V and a source voltage of 0V applied to a plurality of TFTs obtained by the semiconductor device structure of the background art shown in FIG. 5 (a). FIG. 5 (b) shows the transfer characteristics when this is done.

  This background art TFT exhibits p-type characteristics and has an on / off ratio exceeding 100,000. However, it has an excessive p-type carrier, and in order to keep the TFT in a completely off state, it is necessary to continue to apply a voltage of about 30 V to the gate. Continued application of a voltage of about 30 V to the gate to maintain the off state is undesirable from the viewpoint of power consumption and the life of the element. If the gate voltage is not applied (the gate voltage is 0 V) and used in the off state, the effective on / off ratio is reduced to about 700, and the function as the selection switch is impaired.

  Next, electrical characteristics of the semiconductor device according to the embodiment of the present invention will be described. When a mixture of copper phthalocyanine (PB15: Pigment Blue 15) and acrylic resin having the structure of FIG. 2A and an acrylic resin is formed as the dye-containing resin layer 17, it is obtained for a plurality of TFTs of the semiconductor element structure of the present invention. The obtained transfer characteristics are shown in FIG. 3A. By providing the dye-containing resin layer 17, the threshold value is shifted by about 16V in the negative direction. This indicates that the copper phthalocyanine (PB15) and the π orbital on the SWNT surface interacted to suppress the excessive p-type carrier of the SWNT channel. As a result of appropriately adjusting the carrier concentration of the SWNT channel, the TFT can be sufficiently turned off when the gate voltage is 0 V, and the effective on / off ratio reaches 1,500. As a result, a highly practical TFT could be provided.

  When a mixture of metal-free phthalocyanine (PB16: Pigment Blue 16) having the structure shown in FIG. 2B and an acrylic resin is formed as the dye-containing resin layer 17, a plurality of TFTs of the semiconductor device structure of the present invention are used. The obtained transfer characteristics are shown in FIG. 3B. When a mixture of brominated chlorinated copper phthalocyanine (PG36: Pigment Green 36) and acrylic resin having the structure of FIG. 2 (c) and an acrylic resin is formed as the dye-containing resin layer 17, a plurality of TFTs of the semiconductor element structure of the present invention FIG. 3C shows the transfer characteristics obtained for the above. When a mixture of highly chlorinated copper phthalocyanine (PG7: Pigment Green 7) having the structure of FIG. 2D and an acrylic resin is formed as the dye-containing resin layer 17, a plurality of TFTs of the semiconductor element structure of the present invention are formed. The transfer characteristics obtained for this are shown in FIG. 3D.

  Examples of the dye mixed with the resin of the dye-containing resin layer 17 include metal-free phthalocyanine (PB16), brominated chlorinated copper phthalocyanine (PG36), and highly chlorinated copper phthalocyanine (PG7) in addition to the copper phthalocyanine described above. Can be used. As shown in FIGS. 3B to 3D, it has been confirmed that the same effect can be obtained even when these phthalocyanines are used.

  In the pigment blue 16 in FIG. 3B, the same device characteristics as those in the pigment blue 15 in FIG. 3A were obtained. In the pigment green 36 of FIG. 3C, the threshold shift amount is larger than that in the case of the pigment blue 15, and the threshold value is shifted in the negative direction by about 20V. In the case of pigment green 7 in FIG. 3D, the threshold shift amount is smaller than that in the case of pigment blue 15.

  The carrier concentration and the threshold shift amount according to the present invention can be controlled by changing the type, concentration, and / or coating amount of the dye mixed in the dye-containing resin layer. Moreover, after confirming the element characteristics once in the element structure shown in FIG. 5A, these parameters can be adjusted to achieve the desired element characteristics, which is practical. Further, the dye used here has π electrons, and it is essential that the dye interacts with the π electrons of the SWNT channel 16 by contacting the upper surface, the lower surface, or both surfaces of the SWNT channel 16. Phthalocyanines and their metal complexes meet the objectives of the present invention.

  In addition, phthalocyanines and their metal complexes are characterized by having two light absorption bands, mainly called a Q band in the vicinity of a wavelength of 600 to 700 nm as shown in FIG. Yes.

  Further, according to the present invention, the dye that interacts with the π electrons of SWNTs is uniformly dispersed in the resin in advance. Therefore, the handling at the time of manufacture is easy, and at the same time, the concentration adjustment at the time of carrying out is easy. As a result, the adjustment range of the carrier concentration of the target SWNT channel is wide, and controllability is excellent, which is very effective.

(Method for Manufacturing Semiconductor Device of Embodiment)
The semiconductor device according to the first embodiment of the present invention shown in FIG. 1 is manufactured by, for example, the following manufacturing method. For example, a polyimide film having a thickness of 0.1 mm is prepared as the film substrate 11. Next, ink in which silver nanoparticles are dispersed in a solvent is used, and a desired shape is drawn on the film substrate 11 using, for example, an ink jet printer, and then dried. Further, the gate electrode 12 is formed on the film substrate 11 by performing heat treatment at 180 ° C. and sintering.

  Next, an insulator made of an organic polymer such as polyvinylphenol is spin-coated on the film substrate 11 so as to cover the gate electrode 12 and baked at 150 ° C. to form the gate insulating film 13.

  The thickness of the gate insulating film 13 is not particularly limited. However, if it is too thin, it will be difficult to effectively suppress the leakage current between the gate electrode 12 and the other electrodes, and if it is too thick, the switching phenomenon of the channel layer due to the gate bias voltage cannot be effectively controlled. Therefore, the thickness of the gate insulating film 13 is preferably in the range of 10 to 1000 nm.

  Next, silver nanoparticles whose surface is stabilized with an organic substance are dispersed in a solvent, and are drawn in the shape of a desired electrode on the gate insulating film 13 using, for example, an ink jet printer, and dried, and then heated to 180 ° C. Sinter by heat treatment. In this way, the source electrode 14 and the drain electrode 15 arranged at a distance corresponding to the channel length are formed on the gate insulating film 13.

  Next, a CNT ink in which single-walled nanotubes exhibiting semiconductor characteristics are dispersed in a solvent is applied to a predetermined place using a dispenser and dried to form a SWNT channel 16 between the source electrode 14 and the drain electrode 15.

  Further, an acrylic resin containing phthalocyanine was applied using a dispenser so as to cover the SWNT channel 16 and dried to obtain a dye-containing resin layer 17. Such a manufacturing process has a low maximum process temperature, and many engineering plastics can be used as the material of the film substrate 11. Therefore, it is possible to give added value to the manufactured semiconductor device, such as flexibility and transparency, which is impossible with existing solid silicon semiconductor integrated circuits. Further, an expensive vacuum apparatus is not used, and the manufacturing cost can be kept low. In this embodiment, an inkjet printer and a dispenser are used as printing means. However, means such as screen printing, letterpress printing, and offset printing can be used in the same manner. In addition to spin coating, various coating methods such as spray coating, die coating, and dip coating can be used as the coating means.

  Although the embodiments and examples of the present invention have been described above, the above examples can be variously modified based on the technical idea of the present invention. The present invention is not limited to these embodiments and examples. The semiconductor element and the semiconductor device of the present invention are formed by a printing or coating process using a liquid or paste-like material. It is conceivable to use an insulating resin layer containing the dye of the present invention and to function as an interlayer insulating layer such as a channel composed of a plurality of carbon nanotubes or source / drain electrodes. It is conceivable to use an insulating resin layer containing the pigment of the present invention and to function as a cover film for friction resistance or environment resistance of a semiconductor element arranged on a substrate. As the support substrate, a flexible substrate such as a plastic film, paper, or rubber can be used. It goes without saying that various modifications are possible within the scope of the invention described in the claims, and these are also included in the scope of the present invention.

Part or all of the above embodiments and examples can be described as in the following supplementary notes, but are not limited thereto.
(Supplementary note 1) a current path composed of a plurality of carbon nanotubes;
Two electrodes in electrical contact via the current path;
A semiconductor element comprising: a dye and resin mixture layer provided so as to be in contact with a part or all of the current path.
(Appendix 2) a channel composed of a plurality of carbon nanotubes;
A source electrode and a drain electrode electrically connected via the channel;
A thin film transistor having a gate electrode disposed to face the channel across a gate insulating film,
A semiconductor device, further comprising a mixture layer of a dye and a resin provided in contact with the channel.
(Additional remark 3) The semiconductor element of Additional remark 2 further provided with the silica layer provided between the said channel and the said gate insulating film.
(Appendix 4) a channel composed of a plurality of carbon nanotubes;
A source electrode and a drain electrode electrically connected via the channel;
A thin film transistor having a gate electrode disposed to face the channel across a gate insulating film,
The gate insulating film is a semiconductor device comprising a mixture layer of a dye and a resin.
(Appendix 5) The thin film transistor is formed on a support substrate,
The semiconductor element according to any one of appendix 2 to appendix 4, wherein the gate electrode is formed on the support substrate and is disposed so as to face the channel through the gate insulating film.
(Appendix 6) The thin film transistor is formed on a support substrate,
The gate electrode is formed on the support substrate, and the mixture layer of the dye and resin is formed so as to cover a part or all of the channel. Semiconductor element.
(Supplementary note 7) The semiconductor element according to supplementary note 6, wherein the mixture layer of the dye and the resin is formed so as to cover a part of the channel among the channels overlapping in plane with the gate electrode.
(Supplementary note 8) The semiconductor element according to supplementary note 6, wherein the mixture layer of the dye and the resin is formed to cover the channel and at least one of the source electrode and the drain electrode.
(Appendix 9) The thin film transistor is formed on a support substrate,
The dye and resin mixture layer is formed on the support substrate,
The channel is formed on the mixture layer;
The semiconductor element according to appendix 2 or appendix 3, wherein the gate electrode is disposed so as to face the channel through the gate insulating film.
(Appendix 10) The dye according to any one of appendices 1 to 9, wherein the dye is selected such that the π electrons of the plurality of carbon nanotubes constituting the channel interact with each other. Semiconductor element.
(Supplementary Note 11) The semiconductor element according to any one of Supplementary Notes 1 to 9, wherein the mixture layer has the pigment selected from phthalocyanine and a complex thereof.
(Supplementary note 12) A semiconductor device including a plurality of semiconductor elements according to any one of supplementary notes 1 to 10.
(Additional remark 13) The semiconductor device of Additional remark 12 which has a pressure-sensitive conductive rubber sheet formed so that the mixture layer of the said pigment | dye and resin of these semiconductor elements may be covered.
(Additional remark 14) The semiconductor device of Additional remark 13 which has a metal foil formed so that the said pressure-sensitive conductive rubber sheet may be covered.
(Supplementary note 15) The semiconductor device according to any one of supplementary notes 12 to 14, wherein the plurality of semiconductor elements are arranged in a matrix.

11, 31, 41, 51, 61, 71, 81 Film substrate 12, 32, 42, 52, 62, 72, 82 Gate electrode 13, 33, 43, 53, 63, 73, 83 Gate insulating film 14, 34, 44, 54, 64, 74, 84 Source electrode 15, 35, 45, 55, 65, 75, 85 Drain electrode 16, 36, 46, 56, 66, 76, 86 SWNT channel 17, 37, 47, 67, 77 87 Dye-containing resin layer 53 Dye-containing gate insulating film 88 Pressure-sensitive conductive rubber sheet 89 Metal foil 91 Word line 92 Bit line 93 Element pad 94 Peripheral pad 95 Ground 96 Variable resistance

Claims (10)

A current path composed of a plurality of carbon nanotubes;
Two electrodes in electrical contact via the current path;
A semiconductor element comprising: a dye and resin mixture layer provided so as to be in contact with a part or all of the current path. A channel composed of a plurality of carbon nanotubes;
A source electrode and a drain electrode electrically connected via the channel;
A thin film transistor having a gate electrode disposed to face the channel across a gate insulating film,
A semiconductor device, further comprising a mixture layer of a dye and a resin provided in contact with the channel.   The semiconductor device according to claim 2, further comprising a silica layer provided between the channel and the gate insulating film. A channel composed of a plurality of carbon nanotubes;
A source electrode and a drain electrode electrically connected via the channel;
A thin film transistor having a gate electrode disposed to face the channel across a gate insulating film,
The gate insulating film is a semiconductor device comprising a mixture layer of a dye and a resin. The thin film transistor is formed on a support substrate,
5. The semiconductor device according to claim 2, wherein the gate electrode is formed on the support substrate, and is disposed to face the channel with the gate insulating film interposed therebetween. . The thin film transistor is formed on a support substrate,
The gate electrode is formed on the support substrate, and the mixture layer of the dye and resin is formed so as to cover a part or all of the channel. The semiconductor element as described in.   The semiconductor element according to claim 6, wherein the mixture layer of the dye and the resin is formed to cover the channel and at least one of the source electrode and the drain electrode. The thin film transistor is formed on a support substrate,
The dye and resin mixture layer is formed on the support substrate,
The channel is formed on the mixture layer;
The semiconductor element according to claim 2, wherein the gate electrode is disposed so as to face the channel through the gate insulating film.   The semiconductor element according to any one of claims 1 to 8, wherein in the mixture layer, the dye is selected from any of phthalocyanine and a complex thereof.   A semiconductor device comprising a plurality of semiconductor elements according to claim 1.