JP6708379B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

The present invention relates to a semiconductor device and a manufacturing method thereof.

In recent years, along with the development of thin and lightweight display elements such as organic electroluminescence (organic EL) elements, development of materials having high carrier mobility (hereinafter also referred to as “mobility”) as semiconductor elements has been required. Currently, metal oxides such as indium-gallium-zinc oxide having high mobility have been developed (Patent Document 1).

Further, the current semiconductor devices are mainly silicon, and the process requires expensive vacuum equipment and high temperature process. Further, since photolithography is used, it is necessary to go through a plurality of steps. Therefore, there is a problem that the manufacturing cost of the semiconductor element is high. Therefore, as a method of forming a layer composed of inorganic semiconductor particles having high mobility, non-vacuum process such as coating method has been actively studied.

Among semiconductor elements, diodes are important elements used in various applications such as power supply circuits, static electricity protection circuits, and logic circuits, and diodes using the coating method are indispensable for the practical application of low-cost electronics. It is an element.

As one form of a diode, there is a Schottky diode that exhibits a rectifying action by utilizing a difference (Schottky barrier) between an energy level of a conduction band or a valence band of a semiconductor and a Fermi energy of a conductor. Generally, a Schottky diode is composed of a semiconductor and two kinds of conductors having different work functions which are joined to the semiconductor. The material of the Schottky diode is selected so that a Schottky barrier exists for a current flowing in one direction and an ohmic junction is formed for a current flowing in the opposite direction.

Patent Document 2 discloses that a Schottky barrier is formed by forming an organic thin film between indium tin oxide (ITO) and a semiconductor.

International Publication No. 2005/088726 JP, 2005-294785, A

In the case of an inorganic semiconductor, a high temperature of about 300 degrees or higher is required as a film forming temperature of a thin film. Therefore, it is necessary to use a glass substrate or a silicon wafer as a substrate for forming the inorganic semiconductor film, and it is extremely difficult to apply it to a resin substrate or the like, which is required to have impact resistance and flexibility. For example, the diode having the configuration described in Patent Document 2 cannot be formed on a flexible resin base material because a heat treatment after formation requires a high temperature of 500° C. or higher.

Therefore, an object of the present invention is to provide a semiconductor element that can be manufactured by a non-vacuum process and a low temperature process, and can rectify a higher frequency, and a manufacturing method thereof.

The present inventors have completed the present invention as a result of earnest studies to solve the above problems.

That is, the present invention is as follows.
[1]
A first electrode,
An organic layer formed on the first electrode , containing an organic substance having a functional part that is an electron-donating substituent ,
A semiconductor layer formed on the organic layer, containing inorganic semiconductor particles and an organic dielectric having a relative dielectric constant of 10 or more and 150 or less;
A semiconductor element comprising a second electrode formed on the semiconductor layer,
The content of the organic dielectric is 0.5 to 90 mass% with respect to the total amount of the semiconductor layer,
The content of the inorganic semiconductor particles is 10 to 99.5 mass% with respect to the total amount of the semiconductor layer,
Semiconductor device.
[2]
The semiconductor element according to [1], wherein the inorganic semiconductor particles contain at least one selected from the group consisting of metal oxide particles, silicon particles, and compound semiconductor particles.
[3]
The semiconductor element according to [1] or [2], wherein the organic dielectric contains at least one selected from the group consisting of a fluororesin, a hydroxyl group-containing organic compound, and a cyano group-containing organic compound.
[4]
The semiconductor element according to [3], wherein the organic dielectric contains a cyano group-containing organic compound.
[5]
The semiconductor element according to any one of [1] to [4], wherein the organic layer contains an organic substance containing a sulfur atom.
[6]
The organic layer, and a coupling portion having a structure containing a sulfur atom, and the functional unit, between said coupling portion and the functional portion, the alkyl chain, perfluoroalkyl chains, polyethylene oxide chains, or polypropylene oxide chains The semiconductor device according to [5], including the organic substance having one or more linker parts.
[7]
The semiconductor element according to any one of [1] to [6], wherein the film thickness of the organic layer is 0.1 nm or more and 10 nm or less.
[8]
The semiconductor element according to any one of [1] to [7], wherein the semiconductor element is a diode.
[9]
An organic layer and an electrode containing an organic material having a functional part which is an electron-donating substituent , and a coating solution containing inorganic semiconductor particles, an organic dielectric having a relative dielectric constant of 10 or more and 150 or less, and one or more solvents. A coating step of applying a substrate to obtain a coating film;
A drying step of drying the coating film at a drying temperature of 20° C. or higher and 300° C. or lower to remove at least a part of the solvent from the coating film to form a semiconductor layer;
A second electrode forming step of further forming a second electrode on the formed semiconductor layer,
Manufacturing method of semiconductor device.
[10]
The inorganic semiconductor particles include at least one selected from the group consisting of metal oxide particles, silicon particles, and compound semiconductor particles,
The content of the inorganic semiconductor particles in the coating liquid is 0.1% by mass or more and 49.9% by mass or less with respect to the total amount of the coating liquid,
The content of the organic dielectric in the coating liquid is 0.1% by mass or more and 49.9% by mass or less with respect to the total amount of the coating liquid,
The method for manufacturing a semiconductor element according to [9], wherein the content of the solvent in the coating liquid is 0.2% by mass or more and 99.8% by mass or less with respect to the total amount of the coating liquid.
[11]
The organic layer, and a coupling portion having a structure containing a sulfur atom, and the functional unit, between said coupling portion and the functional portion, the alkyl chain, perfluoroalkyl chains, polyethylene oxide chains, or polypropylene oxide chains The method for manufacturing a semiconductor device according to [9] or [10], including the organic substance having one or more linker parts.
[12]
The method for manufacturing a semiconductor element according to any one of [9] to [11], wherein the substrate is an organic material and a diode is formed as the semiconductor element.
[13]
The semiconductor element according to any one of [9] to [12], wherein the organic dielectric contains at least one selected from the group consisting of a fluororesin, a hydroxyl group-containing organic compound, and a cyano group-containing organic compound. Manufacturing method.
[14]
The method for manufacturing a semiconductor element according to [13], wherein the organic dielectric contains a cyano group-containing organic compound.

According to the present invention, it is possible to provide a semiconductor element that can be manufactured by a non-vacuum process and a low temperature process, and can rectify higher frequencies, and a manufacturing method thereof.

It is a schematic block diagram which shows typically the cross section of the Schottky diode 100 of this embodiment. It is a figure which shows the structure of the organic substance contained in an organic layer. It is a figure which shows the current-voltage characteristic (rectification|straightening property) of the semiconductor element of Example 1 (solid line). 5 is a graph showing the results of dynamic characteristics when an AC signal of 100 Hz is input to the diode of Example 1. 5 is a graph showing the results of dynamic characteristics when an AC signal of 1 MHz is input to the diode of Example 1. 7 is a graph showing the results of dynamic characteristics when an AC signal of 0.1 Hz is input to the diode of Comparative Example 1.

Hereinafter, an embodiment of the present invention (hereinafter, referred to as “the present embodiment”) will be described in detail with reference to the drawings as necessary, but the present invention is not limited thereto and the gist thereof. Various modifications are possible without departing from the above. In the drawings, the same elements will be denoted by the same reference symbols, without redundant description. Further, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.

[Semiconductor element]
The semiconductor device of this embodiment includes a first electrode, an organic layer, and a semiconductor layer containing inorganic semiconductor particles and an organic compound having a relative dielectric constant of 3 or more and 150 or less (hereinafter, also referred to as “organic dielectric”). A second electrode, wherein the content of the organic compound is 0.5 to 90 mass% with respect to the total amount of the semiconductor layer, and the content of the inorganic semiconductor particles is , 10 to 99.5 mass% with respect to the total amount of the semiconductor layer.

FIG. 1 is a schematic configuration diagram schematically showing a cross section of the Schottky diode 100 of this embodiment. The Schottky diode 200 includes a substrate 4, a first electrode 3 formed on the substrate 4, an organic layer 5 formed on the first electrode 3, and a semiconductor layer formed on the organic layer 5. 2 and a second electrode 1 formed on the semiconductor layer 2. The semiconductor layer 2 and the organic layer 5 are formed between the first electrode 3 and the second electrode 1, and the semiconductor layer 2 has a form in which the inorganic semiconductor particles 21 are dispersed in the organic dielectric 22.

[First electrode and second electrode]
Each material of the first electrode and the second electrode is not particularly limited, and examples thereof include those that can be generally used as an electrode of a semiconductor element, and more specifically, a metal, a conductive ceramic material, carbon, Conductive organic materials are mentioned. Among these, gold, silver, aluminum, copper, and ITO are preferable from the viewpoint of obtaining good bonding and adhesiveness with the inorganic semiconductor particles.

[Semiconductor layer]
FIG. 1 is a schematic configuration diagram schematically showing a cross section of the Schottky diode 100 of this embodiment. As shown in FIG. 1, the semiconductor layer contains inorganic semiconductor particles and an organic compound having a relative dielectric constant of 3 or more and 150 or less, and may further contain other components (not shown) as necessary. The semiconductor device of this embodiment can solve a plurality of problems by using a semiconductor layer containing inorganic semiconductor particles and an organic dielectric.

First, conventionally, in a semiconductor layer using inorganic semiconductor particles, there is a problem that defects existing on the surface of the inorganic semiconductor particles become trap levels and deteriorate the characteristics of the inorganic semiconductor particles as a semiconductor. Part of this problem can be solved by sintering the semiconductor layer containing the inorganic semiconductor particles at high temperature (high temperature process: temperature exceeds 300° C.). However, when high-temperature sintering is performed, it becomes difficult to exhibit the physical properties (that is, quantum size effect) peculiar to the inorganic semiconductor particles, and a high-temperature process is required, which limits the usable base material. The point remains as a problem. Further, a semiconductor layer made of inorganic semiconductor particles produced by a low temperature process (temperature 20 to 300° C.) has nonuniform contact between the inorganic semiconductor particles and slow carrier movement as compared with a sintered one. Is a problem. However, since low-priced general-purpose resins can be used in the temperature range of the low-temperature process, it is very important in the industrial process that a high-performance semiconductor layer can be formed by the low-temperature process. Therefore, there is a need for a technique for controlling defects on the surface of the inorganic semiconductor particles, controlling the conduction path of carriers, controlling the electronic state, etc. in a low temperature process.

In the semiconductor device of the present embodiment, in order to solve the above problems, by using the inorganic semiconductor particles and the organic dielectric together in the semiconductor layer, the carrier migration is hindered or the carriers are recombined due to the defect becoming a trap level. Can be prevented, and it becomes possible to control defects on the surface of the inorganic semiconductor particles. Therefore, the electric resistance of the semiconductor layer can be reduced and/or the carrier mobility can be improved, as compared with the case where the semiconductor layer is composed of the inorganic semiconductor particles alone by the low temperature process.

In addition, the combined use of the inorganic semiconductor particles and the organic dielectric has the effect of increasing the conduction path of carriers. When the film is formed only of the inorganic semiconductor particles, many places where the inorganic semiconductor particles are not in contact with each other occur. On the other hand, by using the inorganic semiconductor particles and the organic dielectric together, the contact between the inorganic semiconductor particles can be artificially increased. Also, even if the inorganic semiconductor particles are not in close contact with each other, the presence of the organic dielectric in the gap of several nm between the inorganic semiconductor particles makes it possible for carriers to pass through the semiconductor layer. Guessed. As a result, the amount of carriers flowing in the semiconductor layer increases, and the time for carriers to flow in the semiconductor layer also becomes shorter.

Further, by using the inorganic semiconductor particles and the organic dielectric in combination, it is possible to block oxygen around the inorganic semiconductor particles (that is, air existing in the empty wall at the particle interface). As a result, carriers deactivated by oxygen can be reduced, which contributes to improvement of carrier density and mobility.

In addition, the combined use of the inorganic semiconductor particles and the organic dielectric may possibly control the electronic state of the semiconductor layer. In particular, when the dielectric constant of the inorganic semiconductor particles and the dielectric constant of the organic dielectric around the inorganic semiconductor particles are close to each other, or the organic dielectric near the inorganic semiconductor particles is higher than the dielectric constant of the inorganic semiconductor particles. In the case where the dielectric constant of is higher, increasing the electron density of the conduction level has a good effect on the movement of carriers. The effect becomes more remarkable when the dielectric constants of the inorganic semiconductor particles and the organic dielectric around the inorganic semiconductor particles have the same value.

From the viewpoint of diode characteristics, the content of the inorganic semiconductor particles in the semiconductor layer is preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more, 40% from the total amount of the semiconductor layer. Even more preferably, it is at least mass %. From the same viewpoint, the content of the inorganic semiconductor particles in the semiconductor layer is preferably 99.5% by mass or less, more preferably 99% by mass or less, and further preferably 90% by mass or less with respect to the total amount of the semiconductor layer. It is more preferably 80% by mass or less, still more preferably 70% by mass or less.

From the viewpoint of diode characteristics, the content of the organic dielectric in the semiconductor layer is preferably 0.5% by mass or more, more preferably 1% by mass or more, further preferably 10% by mass or more, based on the total amount of the semiconductor layer. , 20% by mass or more is more preferable, and 30% by mass or more is extremely preferable. From the same viewpoint, the content of the organic dielectric in the semiconductor layer is preferably 90% by mass or less, more preferably 80% by mass or less, further preferably 70% by mass or less, based on the total amount of the semiconductor layer. It is even more preferably 60% by mass or less.

The layer thickness of the semiconductor layer is preferably 0.05 μm or more, more preferably 0.1 μm or more, and further preferably 0.2 μm or more, from the viewpoint of diode characteristics. From the same viewpoint, the layer thickness of the semiconductor layer is preferably 500 μm or less, more preferably 200 μm or less, and further preferably 100 μm or less.

The mass% of the organic dielectric contained in the semiconductor layer changes depending on the density of the inorganic semiconductor particles. Therefore, the volume percentage of the organic dielectric in the semiconductor layer is also important. In order to exhibit the flexibility of the semiconductor layer and the effect of the organic dielectric, the content of the organic dielectric in the semiconductor layer is preferably 10% by volume or more, more preferably 20% by volume or more. From the same viewpoint, the content of the organic dielectric in the semiconductor layer is preferably 90% by volume or less, more preferably 80% by volume or less. The content of the inorganic semiconductor particles in the semiconductor layer is preferably 10% by volume or more, more preferably 20% by volume or more. From the same viewpoint, the content of the inorganic semiconductor particles in the semiconductor layer is preferably 90% by volume or less, more preferably 80% by volume or less.

The organic dielectric in the semiconductor layer can function as a binder for the inorganic semiconductor particles. From the viewpoint of carrier transfer, the semiconductor layer is a layer composed of only a single metal oxide particle, a single silicon particle, or a single compound semiconductor particle as an inorganic semiconductor particle, and an organic dielectric. Preferably.

In the semiconductor layer containing the inorganic semiconductor particles and the organic dielectric, the organic dielectric and the inorganic semiconductor particles are preferably uniformly distributed (that is, a uniform dispersion film). By making the distribution uniform, the anisotropy of the electrical characteristics of the semiconductor layer is eliminated, and the conductive characteristics of the semiconductor layer in the thickness direction become constant. As a result, variations in the performance of semiconductor devices using this semiconductor layer are reduced.

In the present embodiment, the "uniform dispersion film" is a film in which the inorganic semiconductor particles and the organic dielectric in the film are uniformly dispersed, and the lower half and the upper half of the inorganic semiconductor particles in the film thickness direction of the film, The ratio of the organic dielectrics is almost the same, and the difference between the ratio (%) of the inorganic semiconductor particles in the lower half and the ratio (%) of the inorganic semiconductor particles in the upper half, that is, the ratio of the inorganic semiconductor particles in the upper half-the ratio of the lower half It is preferable that the ratio of the inorganic semiconductor particles=10 or less. The uniformity in the film thickness direction can be measured by cutting the cross section and measuring the contrast difference of a scanning electron microscope.

Hereinafter, each component forming the semiconductor layer will be described.

(Inorganic semiconductor particles)
The inorganic semiconductor particles are not particularly limited, but examples thereof include metal oxide particles, silicon particles, germanium particles, and compound semiconductor particles. Among these, at least one selected from the group consisting of metal oxide particles, silicon particles, and compound semiconductor particles is preferable. By using such inorganic semiconductor particles, the effects of the above-described semiconductor element tend to be further improved. Hereinafter, each particle will be described. As the inorganic semiconductor particles, the above particles may be used alone or in combination of two or more.

(Metal oxide particles)
The metal oxide used for the metal oxide particles is not particularly limited, but for example, copper (I) oxide, copper (II) oxide, iron oxide, zinc oxide, silver oxide, titanium oxide (rutile type, anatase type) , Aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), indium tin oxide (ITO), tin oxide, fluorine-doped tin oxide (FTO), indium oxide, indium gallium zinc oxide (IGZO), nickel oxide, CuAlO ₂ , CuGaO ₂ , SrCu ₂ O ₂ , LaCuOS, LaCuOSe, CuInO ₂ , ZnRh ₂ O ₄ , 12CaO·7Al ₂ O ₃ (C12A7), Ga ₂ O _{3 and the} like. These metal oxides used for the metal oxide particles may be used alone or in combination of two or more.

The method for producing metal oxide particles is not particularly limited, and examples thereof include a method of pulverizing a metal oxide produced by a sputtering method, a sol-gel method, and the like. As a method for pulverizing the metal oxide, either a dry pulverizing method or a wet pulverizing method may be used, or both methods may be used. A hammer crusher or the like can be used for the dry crushing method. A ball mill, a planetary ball mill, a bead mill, a homogenizer, etc. can be used for the wet pulverization method.

The solvent at the time of wet grinding is not particularly limited, but for example, water, pentane, hexane, peptane, octane, nonane, decane, 2-methylhexane, decalin, tetralin, methanol, ethanol, n-propanol, 2-propanol, n-butanol, t-butanol, ethylene glycol, diethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ethylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, ethylene glycol mono-2-ethylhexyl ether, propylene Ketones such as glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, glycerin acetone, methyl ethyl ketone, benzene, xylene, toluene, phenol, aniline, Examples thereof include aromatics such as diphenyl ether, dimethyl sulfoxide, dimethylformamide, acetonitrile, methyl acetate, tetrahydrofuran, butyl lactate, N-methylpyrrolidone and the like. It is also possible to use these in a mixture.

The surface of the metal oxide particles may be modified with an organic functional group. By modifying the surface with an organic functional group, the dispersibility of the metal oxide particles in the organic solvent used for the coating liquid is improved, and the uniformity of the obtained coating film tends to be further improved. The method of modifying the organic functional group is not particularly limited, and examples thereof include a method of modifying with a cyanoethyl group.

The average particle diameter of the metal oxide particles is preferably 1 nm or more, more preferably 3 nm or more, and further preferably 5 nm or more. When the average particle diameter of the metal oxide particles is 1 nm or more, the contact resistance between the metal oxide particles tends to be further reduced. The average particle size of the metal oxide particles is preferably 1000 nm or less, more preferably 500 nm or less, still more preferably 300 nm or less, and particularly preferably 100 nm or less. When the average particle diameter of the metal oxide particles is 1000 nm or less, the film formability tends to be further improved. The average particle diameter of the metal oxide particles can be measured with a transmission electron microscope or a scanning electron microscope. Further, the average particle size of the metal oxide particles can be adjusted by controlling the conditions of the pulverization method and the sol-gel method.

The relative standard deviation σ of the particle size distribution of the metal oxide particles is preferably 5.0 nm or less, more preferably 3.0 nm or less, and further preferably 2.0 nm or less. When the relative standard deviation σs of the particle size distribution of the metal oxide particles is 5.0 nm or less, the resistance tends to be further reduced. The lower limit of the relative standard deviation σ of the particle size distribution of the metal oxide particles is not particularly limited, but is preferably 0 nm or more, more preferably 0.1 nm or more.

(Silicon particles)
The silicon particles will be described. The method for producing silicon particles is not particularly limited, and for example, a method using a highly crystalline semiconductor microparticle producing apparatus utilizing a pulse pressure addition orifice injection method, a polycrystalline or single crystal silicon ingot or a wafer is crushed. It can be manufactured by a method or the like. In addition, chips and the like during wafer production can also be used as silicon particles. The method for crushing the ingot or the wafer may be dry crushing or wet crushing, or both methods may be used. A hammer crusher or the like can be used for dry crushing. A ball mill, a planetary ball mill, a bead mill, a homogenizer or the like can be used for the wet pulverization. As the solvent at the time of wet pulverization, those mentioned above can be mentioned.

The silicon particles are not particularly limited, but examples thereof include p-type silicon particles, n-type silicon particles, and non-doped silicon particles. The p-type silicon particles (p-type semiconductor) are not particularly limited, and examples thereof include silicon doped with an acceptor such as boron or gallium as an additive. The n-type silicon particles (n-type semiconductor) are not particularly limited, but examples thereof include silicon doped with a donor such as phosphorus, nitrogen, or arsenic as an additive. The concentration of these additives contained in the silicon particles is preferably 1×10 ¹² atom/cm ³ or more, more preferably 1×10 ¹³ atom/cm ³ or more. The concentration of the additive is preferably 1×10 ²¹ atom/cm ³ or less, more preferably 1×10 ²⁰ atom/cm ³ or less. The resistivity of silicon is preferably 0.0001 Ωcm or more, and more preferably 0.001 Ωcm or more, from the viewpoint of the movement of charges in the semiconductor and the spread of the depletion layer. The resistivity is preferably 1000 Ωcm or less, more preferably 100 Ωcm or less.

The average particle diameter of the silicon particles is preferably 100 μm or less, more preferably 70 μm or less, and further preferably 50 μm or less. When the average particle size of the silicon particles is 100 μm or less, the film formability tends to be further improved. The average particle size of the silicon particles is preferably 0.001 μm or more, more preferably 0.01 μm or more, and further preferably 0.1 μm or more. When the average particle diameter of the silicon particles is 0.001 μm or more, the contact resistance between the particles and the electrode tends to be further reduced. The average particle diameter of the silicon particles can be measured by the method described in the examples.

The relative standard deviation σ of the particle size distribution of silicon particles is preferably 5.0 nm or less, more preferably 3.0 nm or less, and further preferably 2.0 nm or less. When the relative standard deviation σs of the particle size distribution of silicon particles is 5.0 nm or less, the resistance tends to be further reduced. The lower limit of the relative standard deviation σ of the particle size distribution of silicon particles is not particularly limited, but is preferably 0 nm or more, more preferably 0.1 nm or more.

(Germanium particles)
Examples of the germanium particles include those using germanium instead of silicon in the above silicon particles.

(Compound semiconductor particles)
The compound semiconductor used for the compound semiconductor particles is not particularly limited, but for example, from the viewpoint of the combination of elements, a III-V group semiconductor in which a group III element and a group V element are combined; a group II element and a group VI element are combined. II-VI group semiconductors; IV-IV group semiconductors in which group IV elements are combined.

The group III (group 13) element used for the group III-V semiconductor is not particularly limited, but examples thereof include aluminum (Al), gallium (Ga), and indium (In). The Group V (Group 15) element is not particularly limited, but examples thereof include nitrogen (N), phosphorus (P), arsenic (As), and antimony (Sb). Specific examples of III-V semiconductors include, but are not limited to, GaN, GaAs, AlN, InP, InSb, and InN.

The Group II (Group 2 or Group 12) element used for the Group II-VI semiconductor is not particularly limited, and examples thereof include magnesium, zinc, cadmium, and mercury. The Group VI (16th group) element is not particularly limited, but examples thereof include oxygen, sulfur, selenium, and tellurium. The specific II-VI group semiconductor is not particularly limited, but examples thereof include ZnS, ZnSe, and CdTe.

The group IV used for the group IV-IV semiconductor is not particularly limited, but examples thereof include carbon (C), silicon (Si), and germanium (Ge). The specific IV-IV group semiconductor is not particularly limited, but examples thereof include SiC and SiGe.

The method for producing the compound semiconductor particles is not particularly limited, and a single crystal or a polycrystal may be crushed and used. As a method of crushing, either dry crushing or wet crushing may be used, or both methods may be used. A hammer crusher or the like can be used for dry crushing. A ball mill, a planetary ball mill, a bead mill, a homogenizer or the like can be used for the wet pulverization. As the solvent at the time of wet pulverization, those mentioned above can be mentioned.

The average particle diameter of the compound semiconductor particles is preferably 100 μm or less, more preferably 70 μm or less, and further preferably 10 μm or less. When the average particle diameter of the compound semiconductor particles is 100 μm or less, the contact resistance between particles tends to be further reduced, and the film formability tends to be further improved. The average particle size of the compound semiconductor particles is preferably 0.001 μm or more, more preferably 0.01 μm or more. When the average particle size of the compound semiconductor particles is 0.001 μm or more, the contact resistance between the particles and the electrode tends to be reduced.

The relative standard deviation σ of the particle size distribution of the compound semiconductor particles is preferably 5.0 nm or less, more preferably 3.0 nm or less, and further preferably 2.0 nm or less. When the relative standard deviation σs of the particle size distribution of the compound semiconductor particles is 5.0 nm or less, the resistance tends to further decrease. The lower limit of the relative standard deviation σ of the particle size distribution of the compound semiconductor particles is not particularly limited, but is preferably 0 nm or more, more preferably 0.1 nm or more.

(Organic compound with relative permittivity of 3 or more and 150 or less)
In the present embodiment, the “relative permittivity” means a value measured by an impedance method with a measurement frequency of 1 kHz and a measurement temperature of 23° C. The relative dielectric constant of the organic compound is 3 or more, preferably 5 or more, and more preferably 10 or more. When the relative dielectric constant of the organic compound is 3 or more, the mobility is further improved. Further, the relative dielectric constant of the organic compound is 150 or less, preferably 100 or less, more preferably 80 or less, further preferably 50 or less, further preferably 35 or less. When the relative dielectric constant of the organic compound is 150 or less, the mobility is further improved.

The organic dielectric is not particularly limited, but examples thereof include fluororesin, polyvinylidene chloride, acrylic resin, acetyl cellulose, aniline resin, ABS resin, ebonite, vinyl chloride resin, acrylonitrile resin, aniline formaldehyde resin, aminoalkyl resin. , Urethane, AS resin, epoxy resin, vinyl butyral resin, silicone resin, vinyl acetate resin, styrene butadiene rubber, silicone rubber, cellulose acetate, styrene resin, dextrin, nylon, soft vinyl butyral resin, furfural resin, polyamide, polyester resin , Polycarbonate resin, phenol resin, furan resin, polyacetal resin, melamine resin, urea resin, polysulfide polymer, polyethylene, bakelite varnish, polyvinyl alcohol, etc. resin; ketone group-containing compound such as acetone, isobutyl methyl ketone; aldehyde group such as formalin Compounds containing: hydroxyl group-containing compounds such as methyl alcohol, isobutyl alcohol, ethyl alcohol, ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, glycerin, cresol glycol, pyranol, phenol, thioglycerol; amino acid group-containing compounds such as aniline; Compounds containing a polymerizable double bond such as allerphthalate; compounds containing a carbon-chlorine bond such as chloropyrene; compounds containing a carboxylic acid group such as succinic acid; dextrin, nitrocellulose, ethyl cellulose, hydroxyethyl cellulose, starch, hydroxypropyl starch, pullulan, glu Examples thereof include sugars such as cidol pullulan, sucrose and sorbitol; and cyano group-containing organic compounds such as succinic nitrile. In particular, one or more selected from the group consisting of a fluororesin, glycerin, thioglycerol, and a cyano group-containing organic compound is preferable from the viewpoint of rectifying property, and particularly from the viewpoint of rectifying a higher frequency. Organic compounds are more preferred.

The organic dielectrics may be used alone or in combination of two or more. In particular, when two or more kinds are used in combination, it is preferable to use a hydroxyl group-containing compound and a cyano group-containing organic compound in combination, and it is more preferable to use two or more hydroxyl group-containing compounds and a cyanoethyl group-containing organic compound in combination.

The cyano group-containing organic compound is not particularly limited as long as it is an organic compound containing one or more cyano groups, and is, for example, a cyanoethyl group-containing organic compound. The cyanoethyl group-containing organic compound is not particularly limited, and examples thereof include cyanoethyl pullulan, cyanoethyl polyvinyl alcohol, cyanoethyl saccharose (cyanoethyl sucrose), cyanoethyl cellulose, cyanoethyl hydroxyethyl cellulose, cyanoethyl starch, cyanoethyl hydroxypropyl starch, cyanoethyl glycidol pullulan, cyanoethyl sorbitol. Etc. By using such a cyano group-containing organic compound, the mobility tends to be further improved.

The fluorine-based resin is not particularly limited, but for example, C ₂ F _m X _n H _4-mn (m represents 1 to 4, n represents 0 to 3, and the sum of m and n does not exceed 4). ) As a skeleton, and a fluorine-based ion exchange resin. The fluoropolymer is not particularly limited, for example, vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, homopolymers or copolymers of fluorine-containing monomers such as chlorotrifluoroethylene, and vinyl fluoride, fluorinated Examples thereof include copolymers of fluorine-containing monomers such as vinylidene, tetrafluoroethylene, chlorotrifluoroethylene and non-fluorine-containing monomers.

The fluorine-based ion exchange resin is not particularly limited, but examples of the ion exchange group include COOH, SO ₃ H, SO ₂ F, SO ₂ Cl, SO ₂ Br, COF, COCl, COBr, CO ₂ CH ₃ , CO. A fluororesin having a group represented by ₂ C ₂ H ₅ may be mentioned. Examples of such a fluororesin include a copolymer of a monomer having the above ion exchanger and a fluorine-containing monomer. More specifically, the general formula _{CF 2 = CF-O (CF} 2 CFX) n O- (CF 2) m and fluorinated vinyl compound represented by -W, fluorinated olefin of the formula CF ₂ = CFZ And at least a binary copolymer. Here, X is F or a perfluoroalkyl group having 1 to 3 carbon atoms, n is an integer of 0 to 3, m is an integer of 1 to 5, Z is H, Cl, F or a perfluoroalkyl group having 1 to 3 carbon atoms. It is a base. W is any of the groups represented by COOH, SO ₃ H, SO ₂ F, SO ₂ Cl, SO ₂ Br, COF, COCl, COBr, CO ₂ CH ₃ , and CO ₂ C ₂ H ₅ .

The relative dielectric constant of an organic compound tends to increase as the organic compound contains an atom or a functional group having high polarity. The dipole moment, which is an index of polarity, can be estimated by the sum of binding moments. As the organic compound having a relative dielectric constant of 3 or more, a compound having a substituent having a binding moment of 1.4 D (D=3.33564×10 ⁻³⁰ Cm) or more is preferable. Substituents having a binding moment of 1.4D or more include OH, CF, CCl, C=O, N=O, CN and the like. The organic compound having a relative dielectric constant of 3 or more and 150 or less, which has these substituents, is not particularly limited, and examples thereof include a fluororesin, glycerin, thioglycerol, and a cyano group-containing organic compound.

The organic dielectric is preferably transparent to some extent. The film made of an organic dielectric has a transmittance of light having a wavelength of 550 nm of preferably 35% or more, more preferably 50% or more, still more preferably 70% or more. The upper limit of the transmittance is not particularly limited, but it is 100% or less. The transmittance can be measured using a spectrophotometer. Quartz glass or a resin substrate can be used as the measurement base material.

The organic dielectric is preferably a high molecular weight organic compound having a molecular weight of 500 or more from the viewpoint of imparting flexibility to the film, and a high molecular weight organic compound having a molecular weight of 500 or more and a low molecular weight organic compound having a molecular weight of less than 500. You may use a compound together.

(Other ingredients)
The semiconductor layer may contain other components, if necessary, in addition to the inorganic semiconductor particles and the organic compound. Other components are not particularly limited, and include, for example, any one or more of a solvent remaining in the semiconductor layer, a binder component, an inorganic component, and the like.

[Aspect of Semiconductor Element]
The semiconductor element of the present embodiment is not particularly limited, but examples thereof include a diode, a transistor, a thin film transistor, a memory, a photodiode, a light emitting diode, a light emitting transistor, a sensor, and the like.

Transistors and thin film transistors are used in various display devices such as active matrix drive type displays, liquid crystal displays, dispersion type liquid crystal displays, electrophoretic displays, electrochromic displays, organic light emitting displays, electronic paper, and particle rotating display devices. It can be used as a display element. Transistors and thin film transistors are used as switching transistors of display pixels, signal driver circuit elements, memory circuit elements, signal processing circuit elements, and the like in these display devices.

A switching transistor of a display device or a display element (collectively referred to as a “display device” hereinafter) is arranged in each pixel of the display device and switches a display state of each pixel. In such an active driving element, patterning of a conductive substrate facing each other is unnecessary, so that the pixel wiring is simplified as compared with a passive driving type display device that does not have a transistor for switching the display state of the pixel depending on the circuit configuration. it can. Usually, one to several switching transistors are arranged per pixel. Such a display device has a structure in which a data line and a gate line, which are two-dimensionally formed on the surface of a substrate, intersect with each other, and the data line and the gate line are respectively connected to the gate electrode, the source electrode, and the drain electrode of the transistor. ing. It is also possible to divide the data line and the gate line, and to add a current supply line and a signal line.

Further, in addition to a pixel wiring and a transistor, a capacitor may be provided in parallel with each pixel of the display device so as to have a function of recording a signal. Further, a driver circuit for data lines and gate lines, a memory circuit for pixel signals, a pulse generator, a signal divider, a controller, and the like can be mounted on a substrate on which a display device is formed.

When the semiconductor element is a thin film transistor, the element structure is, for example, a substrate/gate electrode/insulator layer (dielectric layer)/source electrode/drain electrode/semiconductor layer structure (bottom contact structure), substrate/ Semiconductor layer/source electrode/drain electrode/insulator layer (dielectric layer)/gate electrode structure (top gate structure), substrate/gate electrode/insulator layer (dielectric layer)/semiconductor layer/source electrode/drain electrode Structure (top contact structure) and the like. The insulator layer (dielectric layer) is a gate insulating film, and is made of, for example, an organic compound film having a relative dielectric constant of 3 or more and 150 or less. In addition, a plurality of source electrodes, drain electrodes, and gate electrodes may be provided. In addition, a plurality of semiconductor layers may be provided in the same plane or may be stacked.

Mobility of the semiconductor element (e.g., mobility of the thin film transistor described above), in order to use the device for displaying an image is preferably at least 0.0001 cm ² / Vs, more preferably at least 0.001 cm ² / Vs, It is more preferably 0.01 cm ² /Vs or more.

As the transistor configuration, any of a MOS (metal-oxide (insulator layer)-semiconductor) type transistor and a bipolar type transistor can be adopted in addition to the thin film transistor. The device structure of the bipolar transistor includes, for example, a structure of n-type semiconductor layer/p-type semiconductor layer/n-type semiconductor layer and a structure of p-type semiconductor layer/n-type semiconductor layer/p-type semiconductor layer. An electrode is connected to the semiconductor layer. The semiconductor containing the inorganic semiconductor particles of the present invention and the organic dielectric is used for at least one of the p-type semiconductor layer and the n-type semiconductor layer.

When the semiconductor element is a diode, the element structure is, for example, a structure of electrode/n-type semiconductor layer/p-type semiconductor layer/electrode or electrode/p-type semiconductor layer/electrode or electrode/n-type semiconductor. A layer/electrode structure may be mentioned. Further, an organic layer can be provided between the electrode and the semiconductor layer. A semiconductor layer containing inorganic semiconductor particles and an organic dielectric is used as the p-type semiconductor layer or the n-type semiconductor layer.

Further, the diode can be formed only by applying the Schottky junction and/or the tunnel junction to the semiconductor layer containing the inorganic semiconductor particles and the organic dielectric. A semiconductor element having such a junction structure is preferable because a diode can be manufactured with a simple structure. Further, a plurality of semiconductor elements having such a junction structure can be joined to form elements such as an inverter, an oscillator, a memory circuit, and a sensor.

Further, the semiconductor element of this embodiment can be used as an arithmetic element or a storage element in an electronic device such as an IC card, a smart card, or an electronic tag. In that case, it can be applied without problems whether these are contact type or non-contact type. These IC card, smart card, and electronic tag are configured with a memory, a pulse generator, a signal divider, a controller, a capacitor, and the like, and may further include an antenna and a battery.

Next, a specific example of the semiconductor element will be shown.

FIG. 1 is a sectional view schematically showing a configuration example of a semiconductor element 100 according to this embodiment. As shown in FIG. 1, the semiconductor element 100 is a diode, and includes a base material 4, a first electrode 3 formed on the base material 4, an organic layer 5, a semiconductor layer 2, and a second electrode 1. Have. The semiconductor layer 2 is composed of semiconductor particles 21 and an organic dielectric 22. The material of the base material 4 is as described above. Further, the base material 4 may have a surface smoothing film on the base material, and the surface smoothing film is as described above. The organic layer 5 may be formed between the second electrode 1 and the semiconductor layer 2.

<Substrate>
The material of the base material 4 is not particularly limited as long as it can support the semiconductor element 100, but an organic material, an inorganic material, or an organic-inorganic composite material can be used. In particular, organic materials and organic-inorganic composite materials are preferable because they have excellent flexibility. Specific examples of the organic material include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), cycloolefin polymer (COP), polyimide (PI), acrylic plate, fiber film such as carbon nanofiber, and others. Paper or the like can be used. In particular, paper, PET and PEN are preferable because they are available at low cost. Examples of the organic-inorganic composite material include an organic material in which an inorganic filler is dispersed.

The base material 4 may have a surface smoothing film (not shown) on the base material 4. As a material for forming the surface smooth film, an organic material described later is preferable because it has excellent workability, flatness, and flexibility. For example, polyimide, polyethylene terephthalate (PET), polyether sulfone (PES), polyethylene naphthalate (PEN), polyester, polycarbonate (PC), polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polyacetal, polyarylate (PAR). ), polyamide (PA), polyamide imide (PAI), polyether imide (PEI), polyphenylene ether (PPE), polyphenylene sulfide (PPS), polyether ketone (PEK), polyphthalamide (PPA), polyether nitrile ( PEN), polybenzimidazole (PBI), polycarbodiimide, polysiloxane, polymethacrylamide, nitrile rubber, acrylic rubber, polyethylene tetrafluoride, epoxy resin, phenol resin, melamine resin, urea resin, polymethyl methacrylate resin (PMMA) ), polybutene, polypentene, ethylene-propylene copolymer, ethylene-butene-diene copolymer, polybutadiene, polyisoprene, ethylene-propylene-diene copolymer, butyl rubber, polymethylpentene (PMP), polystyrene (PS), Styrene-butadiene copolymer, polyethylene (PE), polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), polyether ether ketone (PEEK), phenol novolac, benzocyclobutene, polyvinylphenol, polychloropyrene, polyoxymethylene , Polysulfone (PSF) and silicone resin can be used.

The smaller the roughness of the surface of the base material layer, the higher the current density of the current flowing through the Schottky diode. Specifically, the arithmetic mean roughness (Ra) of the surface of the base material layer is preferably 10 nm or less, more preferably 5 nm or less, still more preferably 1 nm or less. In addition, the locally large convex portion existing on the surface of the base material layer 3 locally thins the semiconductor, which causes dielectric breakdown. Therefore, by reducing the local convex portions of the base material 3, the dielectric breakdown strength of the diode is increased, and the reliability and manufacturing yield of the diode can be improved. Specifically, the local protrusions of the base material layer 3 preferably have a maximum height (Ry) of 25 nm or less, more preferably 15 nm or less, and further preferably 5 nm or less.

<Organic layer>
The organic layer is a layer composed of only an organic material or a layer composed of an organic material and other components. Examples of the other component include a solvent for dissolving or dispersing an organic substance.

Here, the organic substance is a compound containing a carbon atom, preferably an organic substance further containing a sulfur atom, and more preferably an organic substance having a thiol group. By using such an organic substance, a denser film can be produced, which tends to contribute to the reduction of resistance.

The compound having a sulfur atom is not particularly limited, for example, 1-butanethiol, 1-decanethiol, 1-dodecanethiol, 1-heptanethiol, 1-hexadecanethiol, 1-hexanethiol, 1-nonanethiol, 1-octadecanethiol, 1-octanethiol, 1-pentadecanethiol, 1-pentanethiol, 1-propanethiol, 1-tetradecanethiol, 1-undecanethiol, 1H,1H,2H,2H-perfluorodecanethiol, 2- Ethylhexanethiol, 2-methyl-1-propanethiol, 2-methyl-2-propanethiol, 3,3,4,4,5,5,6,6,6-nonafluoro-1-hexanethiol, 3-mercapto -N-nonylpropionamide, 3-methyl-1-butanethiol, 4-cyano-1-butanethiol, cis-9-aoctadecene-1-thiol, methyl 3-mercaptopropionate, tert-dodecylmercaptan, 1,11 -Undecanedithiol, 1,16-hexadecanedithiol, 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-propanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,8- Octanedithiol, 1,9-nonanedithiol, 2,2'-ethylenedioxydiethanethiol, 2,3-butanedithiol, 5,5'-bis(mercaptomethyl)-2,2'-bipyridine, hexaethylene glycol Dithiol, tetraethylene glycol dithiol, benzene-1,4-dithiol, 11-mercaptoundecyl hexaethylene glycol, 11-mercaptoundecyl tetraethylene glycol, 1(11-mercaptoundecyl)imidazole, 1-mercapto-2-propanol , 11-(1H-pyrrol-1-yl)undecane-1-thiol, 11-azido-1-undecanethiol, 11-mercapto-1-undecanol, 11-mercaptoundecanoic acid, 11-mercaptoundecylhydroquinone, 16-mercaptohexadecane Acid, 3-chloro-1-propanethiol, 3-mercapto-1-propanol, 3-mercaptopropionic acid, 4-mercapto-1-butanol, 6-mercapto-1-hexanol, 6-mercaptohexanoic acid, 8-mercapto -1-octanol, 8-mercaptooctanoic acid, 9-mercapto-1-nonano , 1,1′,4′,1″-terphenyl-4-thiol, 1,4-benzenedimethanethiol, 2-phenylethanethiol, 2-aminoethanethiol, 2-aminobenzenethiol, 8 -Amino-1-octanethiol, 6-amino-1-hexanethiol, 11-amino-1-undecanethiol, p-terphenyl-4,4''-dithiol, thiophenol, biphenyl-4-thiol, biphenyl- 4,4-dithiol, 4-mercaptobenzoic acid, 4,4'-bis(mercaptomethyl)biphenyl, 4,4'-dimercaptostilbene, cyclohexanethiol and 1-naphthalenethiol can be mentioned.

In addition, a schematic diagram of the organic material of the organic layer is shown in FIG. The organic layer may have a plurality of organic substances 51 schematically shown in FIG. The organic substance 51 has a coupling portion 51a and a functional portion 51c. Although details will be described later, the organic substance 51 has a linker portion 51b between the binding portion 51a and the functional portion 51c. Not all of the bonding portions 51a included in the organic substance 51 are adjacent to the first electrode 3 or the second electrode 1, but most of the bonding portions 51a are connected to the first electrode 3 or the second electrode 1. It is adjacent. Further, the coupling portion 51a forms a coupling with the first electrode 3 or the second electrode 1 to form an organic layer in which the functional portion 51c is exposed on the surface. In most of the plurality of organic substances 51 included in the organic layer, the coupling portion 51a is arranged on the first electrode 3 or the second electrode 1 side, and the functional portion 51c is arranged on the semiconductor layer 2 side. The electrical interaction between the functional portion 51c and the semiconductor film 2 can control the bonding state between the first electrode 3 or the second electrode 1 and the semiconductor layer 2. When the substrate is on the first electrode 3 side, the organic layer is preferably between the first electrode 3 and the semiconductor layer.

The bonding portion 51a is specifically selected from the structures represented by the following chemical formulas. In particular, the bonding portion 51a preferably has a structure containing a sulfur atom, and has a thiol structure, because it can form a good bond with gold, silver, and copper to form the dense organic layer 3. Is more preferable.

As the functional part 51c, an electron donating substituent or an electron withdrawing substituent can be used. More specifically, the functional unit 51c is more specifically hydrogen, halogen, nitro group, alkyl group (eg, methyl group, isopropyl group, tert-butyl group, etc.), cyano group, aryl group (eg, phenyl group, naphthyl group, thienyl group, etc.). ), haloaryl groups (eg, pentafluorophenyl group, 3-fluorophenyl group, 3,4,5-trifluorophenyl group, etc.), alkenyl group, alkynyl group, amide group, acyl group, alkylcarbonyl group, carboxy group, alkoxy. Group (eg, methoxy group), aryloxy group (eg, phenoxy group, naphthyl group, etc.), haloalkyl group (eg, perfluoroalkyl group, etc.), thiocyano group, alkylsulfonyl group, sulfonamide group, amino group, alkylamino group ( For example, a methylamino group etc.), a dialkylamino group (eg dimethylamino group, diethylamino group etc.), a hydroxyl group and the like can be used. In particular, the functional portion 51c having a π-conjugated structure such as an aryl group can improve the carrier transport ability from the first electrode 3 to the second electrode 1 when the organic layer is on the first electrode 3 side. The functional part 51c having a π-conjugated structure such as an aryl group is preferable.

When there is an organic layer on the first electrode 3 side, whether the functional part 51c is an electron-donating substituent or an electron-withdrawing substituent is determined by the Fermi energy (EF1) of the first electrode 3 and the energy level of the semiconductor. EOSC (HOMO energy level for P-type semiconductor, LUMO energy level for N-type semiconductor) and Fermi energy (EF2) of the second electrode 1 are preferably selected. That is, in the case of EF1<EOSC and EF2<EOSC, and in the case of EF1>EOSC and EF2<EOSC, by selecting an electron donating substituent as the functional unit 51c, the current flowing from the first electrode 3 to the second electrode 1 is selected. A Schottky diode that forms a Schottky junction in the direction and an ohmic junction in the direction of the current flowing from the second electrode 1 to the first electrode 3 can be formed. Further, in the case of EF1>EOSC and EF2>EOSC, and in the case of EF1<EOSC and EF2>EOSC, the electron-withdrawing substituent is selected as the functional part 51c to flow from the first electrode 3 to the second electrode 1. It is possible to form a Schottky diode that has an ohmic junction in the current direction and a Schottky junction in the current direction from the second electrode 1 to the first electrode 3.

As the electron-donating substituent, for example, an alkyl group, an amino group, an alkylamino group, a dialkylamino group, an aryl group or a hydroxyl group is preferably used. As the electron-withdrawing substituent, for example, halogen, cyano group, haloaryl group or haloalkyl group is preferably used.

In addition, the organic substance 51 may have a linker portion between the binding portion 51a and the functional portion 51c. As shown in FIG. 2, the Schottky diode made of the organic material 51 in this embodiment has a linker portion 51b. By including the linker portion 51b, a dense and flat organic layer can be formed, and the diode characteristics of the Schottky diode can be improved.

If the length of the linker portion 51b is too long, the organic material 51 bonded to the first electrode 3 is bent, and the compactness and flatness of the organic layer are reduced. In order to obtain the effect of improving the denseness and flatness of the organic layer, the length of the linker portion 51b is preferably 5 nm or less, more preferably 2.5 nm or less.

As the structure of the linker portion 51b, an alkyl chain, a perfluoroalkyl chain, a polyethylene oxide chain, a polypropylene oxide chain, or a structure containing two or more of these four kinds can be used. In particular, the organic substance 51 having the linker portion 51b having a linear alkyl chain structure having 2 to 40 carbon atoms is preferable because the denser organic layer 5 can be formed. A branched structure may be introduced into the linker portion 51b.

The organic layer can be formed by a coating technique such as coating. Specifically, formation methods such as spin coating, dip coating, spray coating, die coating, inkjet printing, screen printing, gravure printing, offset printing, and reverse transfer printing can be used for forming the organic layer 5. Since a bond is formed between the bonding portion 51a of the organic material 51 and the first electrode 3 or the second electrode 1, by rinsing the coating material coated with the organic layer forming material with a solvent, the organic material 51 An organic layer in which one or more molecules are stacked can be obtained.

The film thickness of the organic layer is preferably 0.1 nm or more, and is 0.5 nm or more, from the viewpoint of reducing the energy loss and heat generation of the diode and realizing a diode with low power consumption and high reliability. Is more preferable. From the same viewpoint, it is preferably 10 nm or less, and more preferably 5 nm or less.

[Method for manufacturing semiconductor element]
The method for manufacturing a semiconductor device according to the present embodiment is a substrate provided with an organic layer and an electrode, a coating liquid containing inorganic semiconductor particles, an organic compound having a relative dielectric constant of 3 or more and 150 or less, and one or more solvents. Alternatively, a coating step of coating on a substrate provided with an electrode to obtain a coating film, and drying the coating liquid at a drying temperature of 20° C. or higher and 300° C. or lower to remove at least a part of the solvent from the coating liquid. And a drying step of forming a semiconductor layer.

It is not particularly limited as long as it is a method including the coating step and the drying step. The coating step of applying a coating liquid on the first electrode of the substrate having electrodes to obtain a coating film, the drying step of forming a semiconductor layer on the first electrode, and the second electrode on the formed semiconductor layer. And a second electrode forming step of forming.

As another aspect, in the method for manufacturing a semiconductor device of the present embodiment, a first electrode forming step of forming a first electrode on a substrate, and forming an organic layer on the first electrode of a substrate including the first electrode An organic layer forming step, an applying step of applying a coating liquid on an organic layer of a substrate including an organic layer and an electrode to obtain a coating film, and a drying step of forming a semiconductor layer on the organic layer are formed. A second electrode forming step of further forming a second electrode on the semiconductor layer may be included in this order.

Hereinafter, each step will be described.

[First electrode forming step]
The first electrode forming step is a step of forming a first electrode on the substrate. As the electrode patterning method in each of the above aspects, for example, methods such as spin coating, dip coating, spray coating, die coating, inkjet printing, screen printing, gravure printing, offset printing, and reverse transfer printing can be adopted. Is. Further, as a method of patterning the electrodes, a vapor deposition method using a vacuum device may be adopted.

The semiconductor element of this embodiment can be formed on a substrate such as glass or resin. Moreover, since the semiconductor layer can be formed by a simple method such as printing or coating a solution, a large number of semiconductor elements can be easily formed at one time in a large area. Therefore, a semiconductor element or a device using the semiconductor element (the above-mentioned display element, arithmetic element, memory element, or the like) can be manufactured at low cost. In addition, manufacturing a semiconductor element using a relatively thin semiconductor layer is effective in reducing the thickness and weight of a device using the semiconductor element.

[Organic layer forming step]
The organic layer forming step is a step of forming an organic layer on the first electrode of the substrate having the first electrode. This step can be performed arbitrarily. As the method of patterning the organic layer, for example, spin coating method, dip coating method, spray coating method, die coating method, ink jet printing, screen printing, gravure printing, offset printing, reverse transfer printing, etc. are adopted in the same manner as the electrode. It is possible.

[Coating process]
In the coating step, a coating liquid containing inorganic semiconductor particles, an organic compound having a relative dielectric constant of 3 or more and 150 or less, and one or more kinds of solvents, a substrate provided with an organic layer and electrodes, or a substrate provided with electrodes. Is a step of applying a coating film to obtain a coating film. As for the method of patterning the coating film, similar to the method of electrodes, for example, spin coating method, dip coating method, spray coating method, die coating method, inkjet printing, screen printing, gravure printing, offset printing, reverse transfer printing, etc. are adopted. It is possible.

For example, in the case of manufacturing a diode having a structure of substrate/electrode/organic layer/semiconductor layer/electrode, the coating step is a step of coating a coating liquid on a substrate on which an electrode or an organic layer is formed to obtain a coating film. ..

(Coating liquid)
The coating liquid contains inorganic semiconductor particles, an organic compound (organic dielectric) having a relative dielectric constant of 3 or more and 150 or less, and one or more kinds of solvents. Two or more kinds of inorganic semiconductor particles, organic dielectrics and solvents may be mixed. Regarding the inorganic semiconductor particles and the organic compound having a relative dielectric constant of 3 or more and 150 or less, the same ones as described above can be used. The inorganic semiconductor particles contained in the coating liquid are preferably one or more selected from the group consisting of metal oxide particles, silicon particles, and compound semiconductor particles.

(solvent)
The solvent contained in the coating liquid is not particularly limited, but for example, water, pentane, hexane, peptane, octane, nonane, decane, 2-methylhexane, decalin, tetralin, methanol, ethanol, n-propanol, 2-propanol. , N-butanol, t-butanol, ethylene glycol, diethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ethylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, ethylene glycol mono-2-ethylhexyl ether, Propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, glycerin acetone, ketones such as methyl ethyl ketone, benzene, xylene, toluene, phenol, aniline , Aromatics such as diphenyl ether, dimethyl sulfoxide, dimethylformamide, acetonitrile, methyl acetate, tetrahydrofuran, butyl lactate, and N-methylpyrrolidone. It is also possible to use these in a mixture.

(Surfactant)
The coating liquid may also contain a surfactant. Examples of the surfactant include anionic surfactants, cationic surfactants, amphoteric surfactants and nonionic surfactants. Specifically, the anionic surfactant is not particularly limited, but examples thereof include fatty acid sodium, monoalkyl sulfate, alkylbenzene sulfonate, and monoalkyl phosphate. The cationic surfactant is not particularly limited, and examples thereof include alkyl trimethyl ammonium salt, dialkyl dimethyl ammonium salt, and alkyl benzyl methyl ammonium salt. Examples of the amphoteric surfactant include alkyldimethylamine oxide and alkylcarboxybetaine. The nonionic surfactant is not particularly limited, and examples thereof include polyoxyethylene alkyl ether, fatty acid sorbitan ester, alkyl polyglycoside, fatty acid-time ethanolamide, and alkyl monoglyceryl ether.

You may have a coating liquid preparation process before a coating process. The coating liquid preparation step is a step of preparing a coating liquid from inorganic semiconductor particles, an organic dielectric, and at least one solvent. The solvent is a liquid for dissolving or dispersing the inorganic semiconductor particles and the organic dielectric. The inorganic semiconductor particles, the organic dielectric, and one or more kinds of solvents are mixed to obtain a coating liquid for forming a semiconductor layer. Here, the solvent is different from the organic dielectric. As the solvent, those mentioned above are used.

The content of the inorganic semiconductor particles contained in the coating liquid for forming the semiconductor layer is preferably 0.1% by mass or more, and more preferably 0.5% by mass, based on the total amount of the coating liquid. Further, the same content is preferably 49.9 mass% or less, and preferably 40 mass% or less. When the content of the inorganic semiconductor particles is within the above range, the stability of the coating liquid tends to be improved, and the film thickness tends to be optimum after coating.

The content of the organic compound having a relative dielectric constant of 3 or more and 150 or less (that is, an organic dielectric) contained in the coating liquid for forming the semiconductor layer is preferably 0.1% by mass or more based on the total amount of the coating liquid, 0.5% by mass is more preferable. Further, the same content is preferably 49.9 mass% or less, and preferably 40 mass% or less. When the content of the organic compound having a relative dielectric constant of 3 or more and 150 or less is within the above range, the stability of the coating solution is improved, and the optimum film thickness tends to be obtained after coating.

The content of the solvent contained in the coating liquid for forming the semiconductor layer is preferably 0.2% by mass or more, and 1% by mass, based on the total amount of the coating liquid, from the viewpoint of adjusting the viscosity and making the coating liquid easy to handle. The above is preferable and 5 mass% or more is more preferable. Further, the same content is preferably 99.8% by mass or less, and preferably 98.5% by mass or less.

[Drying process]
The drying step is a step of drying the coating liquid at a drying temperature of 20° C. or higher and 300° C. or lower to remove at least a part of the organic substance from the coating liquid to form a semiconductor layer. This drying step is a low temperature process that differs from conventional high temperature sintering. The “low temperature process” refers to a temperature range of 20° C. or higher and 300° C. or lower in this embodiment. At the temperature in this region, the resin substrate can be used, which is a very important temperature region in the industrial process. The temperature range of this drying step is preferably 20°C or higher and 300°C or lower, more preferably 20°C or higher and 200°C or lower, and further preferably 20°C or higher and 150°C or lower. When the temperature is 150°C or lower, inexpensive general-purpose substrates such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), acrylic plate and paper can be used, which is optimal.

When the semiconductor layer of the semiconductor element is formed by a printing method or a coating method, it is preferable to perform the coating step and the drying step to form the semiconductor layer. Further, the step of preparing the coating liquid used in the coating step (that is, the coating liquid preparation step) may be performed on the same production line as the coating step, or on a manufacturing line different from the coating step or another manufacturing factory. You can go. Alternatively, the coating liquid may be purchased from outside the company. In the present invention, printing is one mode of application, the application liquid may be the printing liquid, and the application process may be the printing process. Specific examples of the coating method or printing method in the coating step include spin coating, dip coating, spray coating, die coating, inkjet printing, screen printing, gravure printing, offset printing, reverse transfer printing, and the like.

[Second electrode forming step]
The second electrode forming step is a step of further forming a second electrode on the formed semiconductor layer. As the patterning method of the second electrode in each of the above aspects, the same method as the patterning method of the first electrode can be mentioned.

The semiconductor element obtained by the manufacturing method of the present embodiment is preferably a diode, and particularly preferably a diode formed on a substrate made of an organic material.

<Effects of this embodiment>
According to this embodiment, as shown in FIG. 1, the semiconductor particles 21 and the organic dielectric 22 are mixed to form a composite film of inorganic semiconductor particles and an organic dielectric as a semiconductor layer of a semiconductor element. .. In this composite film, there are many carrier conduction paths, and further carrier traps and recombination are suppressed. Also, this composite film can block ambient oxygen. As a result, the amount of carriers flowing increases and the moving speed of carriers also increases. This makes it possible to provide a semiconductor element that can rectify a high frequency and that is stable even in air (that is, it does not easily undergo a chemical change even when it comes into contact with air and does not easily deteriorate).

Further, the semiconductor layer containing the inorganic semiconductor particles and the organic dielectric does not require a vacuum process or the like, and can be formed by a low cost and low temperature process, and a non-vacuum process such as a coating method or a printing method. Can be formed with. This makes it possible to reduce the manufacturing cost of the semiconductor element.

As described above, according to the present embodiment, it is possible to provide a semiconductor element which can be manufactured by a non-vacuum process and has a higher operating frequency.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The present invention is not limited to the following examples.

<Evaluation method>
Hereinafter, unless otherwise specified, the evaluation was performed under the conditions of 25° C. and a humidity of 45%.

(1) Average particle size (metal oxide particles)
When the particle diameter was 1 μm or more, the average particle diameter was measured using a desk-top scanning microscope CarryScope JCM5100 (manufactured by JEOL). The particle size was measured at a total of 10 points, and the average value was defined as the average particle size.

Moreover, when the particle diameter was less than 1 μm, it was measured using a transmission electron microscope (TEM) HF-2000 (manufactured by Hitachi, Ltd.). As a specific measuring method, a titanium oxide dispersion liquid TKS201 (anatase type, manufactured by Teika, solid content 33% by mass) will be described as an example. First, the titanium oxide dispersion liquid was diluted to 2000 times, the diluted dispersion liquid was ultrasonically dispersed, and the product soaked in the mesh was freeze-dried to obtain a TEM measurement sample. The TEM measurement sample of this titanium oxide was magnified up to 570000 times with a TEM and observed. The Pixel number of the obtained particle image was calculated, and the diameter obtained by converting each particle into a perfect circle was calculated from the Pixel number by the following formulas [1] and [2].
Perfect circle conversion radius = (Pixel number/π) ² ... [1]
True circle equivalent diameter = True circle equivalent radius x 0.22 x 2... [2]
The total circle conversion diameter of 100 particles (current number of particles) was measured by the above method, and the average value was defined as the average particle diameter.

(Silicon particles)
Regarding silicon particles, 100 particles were randomly selected with a microscope, and the arithmetic mean value of the particle diameters evaluated by the equivalent circle diameter using image analysis was taken as the average particle diameter. A digital microscope manufactured by Keyence Corporation was used as a microscope. When the particle size is less than 1 μm, the particle size can be measured by the same method as for the metal oxide particles.

(Compound semiconductor particles)
Regarding the compound semiconductor particles, the particle size can be measured by the same method as for the metal oxide particles.

(2) Specific permittivity The specific permittivity is a value measured by an impedance method at a measurement frequency of 1 kHz and a measurement temperature of 23°C. Specifically, it was determined from the following formula [3] using an LCR meter (4284A PRESISION LCR meter manufactured by Agilent).
Dielectric constant of sample=(distance between electrodes×electrostatic capacity)/(area of electrode×dielectric constant of vacuum)... [3]
(However, the dielectric constant of vacuum is 8.854×10 ⁻¹² (F/m).)

When the sample is a liquid, the dielectric constant is measured by inserting an electrode into the liquid using a jig for liquid measurement (16452 ALIQUID TEST FIXTURE made by Agilent).

When the sample is a solid, the dielectric constant is measured by forming a film on the electrode plate using a film measuring jig (16451B DIELECTRIC TEST FIXTURE made by Agilent) and sandwiching the film with one electrode. In Example 1 below, a film was formed on an electrode plate and the relative dielectric constant was measured.

(3) Film Thickness The film thickness of each layer was measured with vertscan 2.0 (manufactured by Ryoka System Inc.). For each layer, the layer thickness was arbitrarily measured at 5 locations, and the average thereof was calculated to obtain the average layer thickness.

(4) Evaluation of diode characteristics As an apparatus, an oscilloscope TBS1072B-EDU (manufactured by Tektronix) and a function/arbitrary waveform generator 33210A (manufactured by Keysight) were used. First, one electrode of the diode was connected to an arbitrary waveform generator, and the other electrode was connected to an oscilloscope having an internal impedance of 1 MΩ. The oscilloscope and the arbitrary waveform generator have the same ground. An AC signal of 1 MHz or 100 Hz and a voltage (Vp-p) of 6 V or 2 V was input to the diode from the arbitrary waveform generator, and the potential of the electrode was measured with an oscilloscope.

[Example 1]
(Method for producing substrate A)
Gold was vapor-deposited on a PEN (polyethylene naphthalate) film substrate to a thickness of 60 nm using a vacuum vapor deposition device VPC1100 (manufactured by ULVAC, Inc.). The obtained PEN film with a gold electrode was subjected to UV ozone treatment for 5 minutes and then dry-cleaned. The PEN film after the dry cleaning was immersed in a 2-aminoethanethiol 5 mM solution (solvent: ethanol) for 16 hours. The PEN film after immersion was rinsed with ethanol and dried by air blow to prepare a substrate A with an aminoethanethiol film (organic layer). The film thickness of the aminoethanethiol film was 1 nm.

(Method for manufacturing diode)
A p-type silicon wafer (3 Ωcm) was crushed in an ethanol solvent using a mortar to obtain a liquid containing crushed silicon particles and ethanol. The resulting liquid was agitated to remove large particles that initially settled. Then, the liquid was filtered through a nylon mesh having an opening of 37 μm to remove silicon particles having a particle diameter of less than 37 μm. When the particle size of the obtained silicon particles (filtrate) was measured, the particle size was 37 μm or more and 150 μm or less, and the average particle size was 60 μm.

On the other hand, as an organic dielectric, glycerin, 20% cyanoethyl polyvinyl alcohol (solvent: 2 methoxy ethanol) and 20% cyanoethyl saccharose (solvent: 2 methoxy ethanol) were mixed to prepare a mixed liquid A. The mixing weight ratio of the organic dielectric was glycerin:cyanoethyl polyvinyl alcohol:cyanoethyl saccharose=0.4:0.26:0.34.

The silicon particles and the mixed solution A were mixed so that the weight ratio of the silicon particles and the organic dielectric was 1:1. Further, the obtained mixed liquid was mixed with ethanol in an amount twice as much as the weight of the silicon particles for adjusting the viscosity, to prepare a mixed liquid B.

A coating film was formed on the substrate A by spin coating (2000 rpm×30 seconds) using the obtained mixed liquid B. After that, the coating film was dried at 120° C. for 3 minutes and 2-methoxyethanol was removed to form a semiconductor layer. The thickness of the obtained semiconductor layer was 350 μm.

Finally, an electrode was formed by vapor-depositing 70 nm of gold on the obtained semiconductor layer using a vacuum vapor deposition device VPC1100 (manufactured by ULVAC) to obtain a semiconductor element.

[Comparative Example 1]
Gold was vapor-deposited on a PEN (polyethylene naphthalate) film substrate to a thickness of 50 nm using a vacuum vapor deposition device VPC1100 (manufactured by ULVAC, Inc.). The obtained PEN film with a gold electrode was subjected to UV ozone treatment for 5 minutes and then dry-cleaned. Phthalocyanine copper was vapor-deposited on the PEN film after dry cleaning using a vacuum vapor deposition device VPC1100 (manufactured by ULVAC) to form a semiconductor layer. The thickness of the obtained semiconductor layer was 160 nm. Finally, an electrode was formed by vapor-depositing aluminum to a thickness of 60 nm on the obtained semiconductor layer using a vacuum vapor deposition device VPC1100 (manufactured by ULVAC) to obtain a semiconductor element.

(Evaluation result of diode characteristics)
FIG. 3 shows current-voltage characteristics (rectifying property) of the semiconductor device of Example 1 (solid line). From FIG. 3, it was found that the semiconductor element obtained in Example 1 was an element (diode) through which a current flows in one direction.

Further, FIG. 4 shows the results of the dynamic characteristics when an AC signal of 100 Hz was input to the diode of Example 1, and FIG. 5 shows the results of the dynamic characteristics when an AC signal of 1 MHz was input to the diode of Example 1. The results are shown. As a result, by using the diode of Example 1, it succeeded in rectifying the AC signals of 1 MHz and 100 Hz. From this, it was confirmed that according to the present invention, a very high frequency can be rectified as a diode manufactured by a printing method.

On the other hand, FIG. 6 shows the results of the dynamic characteristics when an AC signal of 0.1 Hz was input to the diode of Comparative Example 1. From FIG. 6, it can be seen that when the diode of Comparative Example 1 is used, the output voltage is small despite the low frequency of 0.1 Hz. Furthermore, when the AC signal was set to 1 Hz, the diode of Comparative Example 1 was not rectified.

The present invention is not limited to the embodiments and examples described above. Based on the knowledge of those skilled in the art, design changes and the like may be added to the embodiments and the examples, and the embodiments and the examples may be arbitrarily combined, and the mode in which such changes and the like are added is also included. Within the scope of the present invention.

INDUSTRIAL APPLICABILITY The present invention has industrial applicability as a semiconductor device.

1 2nd electrode 2 semiconductor layer 3 1st electrode 4 base material 5 organic layer 21 semiconductor particles 22 organic dielectric

Claims (14)

A first electrode,
An organic layer formed on the first electrode , containing an organic substance having a functional part that is an electron-donating substituent ,
A semiconductor layer formed on the organic layer, containing inorganic semiconductor particles and an organic dielectric having a relative dielectric constant of 10 or more and 150 or less;
A semiconductor element comprising a second electrode formed on the semiconductor layer,
The content of the organic dielectric is 0.5 to 90 mass% with respect to the total amount of the semiconductor layer,
The content of the inorganic semiconductor particles is 10 to 99.5 mass% with respect to the total amount of the semiconductor layer,
Semiconductor device. The semiconductor element according to claim 1, wherein the inorganic semiconductor particles include at least one selected from the group consisting of metal oxide particles, silicon particles, and compound semiconductor particles. The semiconductor element according to claim 1, wherein the organic dielectric contains at least one selected from the group consisting of a fluororesin, a hydroxyl group-containing organic compound, and a cyano group-containing organic compound. The semiconductor element according to claim 3, wherein the organic dielectric contains a cyano group-containing organic compound. The semiconductor element according to claim 1, wherein the organic layer contains an organic substance containing a sulfur atom. The organic layer, and a coupling portion having a structure containing a sulfur atom, and the functional unit, between said coupling portion and the functional portion, the alkyl chain, perfluoroalkyl chains, polyethylene oxide chains, or polypropylene oxide chains The semiconductor device according to claim 5, comprising the organic substance having one or more linker parts. The semiconductor element according to claim 1, wherein the organic layer has a film thickness of 0.1 nm or more and 10 nm or less. The semiconductor element according to claim 1, wherein the semiconductor element is a diode. An organic layer and an electrode containing an organic material having a functional part which is an electron-donating substituent , a coating solution containing inorganic semiconductor particles, an organic dielectric having a relative dielectric constant of 10 or more and 150 or less, and one or more solvents A coating step of applying a substrate to obtain a coating film;
A drying step of drying the coating film at a drying temperature of 20° C. or higher and 300° C. or lower to remove at least a part of the solvent from the coating film to form a semiconductor layer;
A second electrode forming step of further forming a second electrode on the formed semiconductor layer,
Manufacturing method of semiconductor device. The inorganic semiconductor particles include at least one selected from the group consisting of metal oxide particles, silicon particles, and compound semiconductor particles,
The content of the inorganic semiconductor particles in the coating liquid is 0.1% by mass or more and 49.9% by mass or less with respect to the total amount of the coating liquid,
The content of the organic dielectric in the coating liquid is 0.1% by mass or more and 49.9% by mass or less with respect to the total amount of the coating liquid,
The method for manufacturing a semiconductor element according to claim 9, wherein the content of the solvent in the coating liquid is 0.2% by mass or more and 99.8% by mass or less with respect to the total amount of the coating liquid. The organic layer, and a coupling portion having a structure containing a sulfur atom, and the functional unit, between said coupling portion and the functional portion, the alkyl chain, perfluoroalkyl chains, polyethylene oxide chains, or polypropylene oxide chains The method for manufacturing a semiconductor device according to claim 9, further comprising the organic substance having one or more linker parts. The method for manufacturing a semiconductor element according to claim 9, wherein the substrate is an organic material, and a diode is formed as the semiconductor element. The semiconductor device according to any one of claims 9 to 12, wherein the organic dielectric contains at least one selected from the group consisting of a fluororesin, a hydroxyl group-containing organic compound, and a cyano group-containing organic compound. Method. The method for manufacturing a semiconductor device according to claim 13, wherein the organic dielectric contains a cyano group-containing organic compound.