WO2014002904A1 - Metal oxide, metal oxide semiconductor film, electroluminescent element, and display device - Google Patents

Metal oxide, metal oxide semiconductor film, electroluminescent element, and display device Download PDF

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WO2014002904A1
WO2014002904A1 PCT/JP2013/067118 JP2013067118W WO2014002904A1 WO 2014002904 A1 WO2014002904 A1 WO 2014002904A1 JP 2013067118 W JP2013067118 W JP 2013067118W WO 2014002904 A1 WO2014002904 A1 WO 2014002904A1
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metal oxide
oxide semiconductor
semiconductor film
specific resistance
gas
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French (fr)
Japanese (ja)
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学 二星
菊池　克浩
伸一 川戸
越智　貴志
優人 塚本
知裕 小坂
智文 大崎
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シャープ株式会社
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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G3/00—Compounds of copper
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
    • C23C14/08—Oxides
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
    • C23C14/34—Sputtering
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/58—After-treatment
    • C23C14/5806—Thermal treatment
    • C23C14/5813—Thermal treatment using lasers
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/58—After-treatment
    • C23C14/5846—Reactive treatment
    • C23C14/5853—Oxidation
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/17—Carrier injection layers
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/40—Electric properties

Definitions

  • the present invention relates to an electroluminescence element and a display device including a metal oxide semiconductor film formed by sputtering or vapor deposition of metal oxide.
  • oxide semiconductor layers eg, InGaZnOx oxide semiconductor layers
  • semiconductors can be obtained.
  • the characteristics of the element can be greatly improved, and the display quality of the display device is also improved.
  • EL elements electroluminescence elements
  • a semiconductor layer exhibiting p-type semiconductor characteristics that are being actively studied as a hole injection layer and a hole transport layer As a semiconductor layer exhibiting p-type semiconductor characteristics that are being actively studied as a hole injection layer and a hole transport layer, The use of an oxide semiconductor layer has been studied.
  • LaCuOS compounds As a semiconductor layer exhibiting p-type semiconductor characteristics, for example, as described in Patent Document 1, sulfides such as LaCuOS compounds have been studied. However, La (lanthanum) which is a rare metal is used. It is used, higher material cost and, because the cause of instability of the sulfide (low moisture resistance), it was difficult to adapt to the mass production process, MoO x and Vo x O y and moisture resistance (material From the viewpoint of high stability) and low cost (a large amount of reserves), an oxide semiconductor layer such as CuAlO 2 has attracted attention.
  • La lanthanum
  • MoO x and Vo x O y and moisture resistance material From the viewpoint of high stability
  • low cost a large amount of reserves
  • Japanese Patent Publication Japanese Patent Laid-Open No. 2006-93619 (published on April 6, 2006)
  • an oxide semiconductor layer such as MoO x , Vo x O y, or CuAlO 2 containing CuAl 2 O 4 formed by a conventional method is used as a hole injection layer in the EL device field for the following reasons. It was difficult to use it suitably as a hole transport layer.
  • a light emitting layer having a large ionization potential energy such as a phosphorescent light emitting material or a quantum dot material capable of realizing deeper blue light emission.
  • a large ionization potential energy also referred to as ionization potential
  • an oxide semiconductor layer such as MoO x , Vo x O y, or CuAlO 2 containing CuAl 2 O 4 formed by conventional dry mixing has a relatively small ionization potential energy, such ionization potential energy is low. There is a problem that it does not function sufficiently as a hole injection layer or a hole transport layer of a large light emitting layer.
  • the present invention has been made in view of the above problems, and is a relatively ionization potential that can sufficiently function as a hole injection layer or a hole transport layer of a light emitting layer having a large ionization potential energy by sputtering or vapor deposition.
  • An object is to provide a film, an electroluminescent element with improved luminous efficiency, and a display device with improved display quality.
  • the metal oxide of the present invention is a Cu element obtained from copper oxide and aluminum oxide that are weighed so that the atomic ratio of Cu element to Al element is 1: 1. And a mixed powder obtained by wet-mixing the copper oxide and the aluminum oxide while being pulverized in the presence of a solvent under an inert gas or a reducing atmosphere. It is characterized by being obtained by pulverization after heat treatment at 900 ° C. or more, and having a specific resistance value of 1.0 ⁇ 10 6 ⁇ cm or less in a state of being pressed and solidified.
  • the mixed powder obtained by dry-mixing the copper oxide and the aluminum oxide which is a conventional method, is heat-treated under an inert gas, and then pulverized to obtain a metal oxide in a state of being pressed and solidified.
  • the resistivity value is relatively high.
  • a metal oxide obtained by such a conventional method a hole injection layer or a hole transport layer of a light emitting layer having a large ionization potential energy even when sputtering or vapor deposition is performed.
  • the metal oxide of the present invention is a mixed powder obtained by wet mixing while pulverizing the copper oxide and the aluminum oxide in the presence of a solvent at 900 ° C. or higher under an inert gas or a reducing atmosphere. Since the specific resistance value in the state of being pressurized and solidified is 1.0 ⁇ 10 6 ⁇ cm or less because it is pulverized after heat treatment with, the sputtering or vapor deposition is performed using the metal oxide of the present invention. For example, a metal oxide semiconductor film having a relatively large ionization potential energy that can sufficiently function as a hole injection layer or a hole transport layer of a light emitting layer having a large ionization potential energy can be formed.
  • the metal oxide semiconductor film of the present invention is formed by sputtering or vapor-depositing a material obtained by solidifying the metal oxide under pressure under an inert gas. It is said.
  • a positive light emitting layer having a large ionization potential energy can be obtained.
  • a metal oxide semiconductor film having a relatively large ionization potential energy that can function sufficiently can be formed.
  • an electroluminescent element of the present invention is an electroluminescent element having an anode and a cathode, and having a light emitting layer between the anode and the cathode.
  • the electroluminescent device of the present invention includes a metal oxide semiconductor film that can adjust the ionization potential energy so that it can sufficiently function as a hole injection layer or a hole transport layer of a light emitting layer having a large ionization potential energy. Therefore, the luminous efficiency can be improved regardless of the combination with any light emitting layer.
  • the display device of the present invention is characterized by including the electroluminescence element in order to solve the above-described problems.
  • the display device includes an electroluminescence element with improved light emission efficiency, display quality can be improved.
  • the metal oxide of the present invention is a mixed powder obtained by wet mixing while pulverizing the copper oxide and the aluminum oxide in the presence of a solvent under an inert gas or a reducing atmosphere. After the heat treatment at 900 ° C. or more, the specific resistance value obtained by pulverization and solidified under pressure is 1.0 ⁇ 10 6 ⁇ cm or less.
  • the metal oxide semiconductor film of the present invention is formed by sputtering or vapor-depositing a material obtained by pressurizing and solidifying the metal oxide under an inert gas.
  • a material obtained by pressurizing and solidifying the metal oxide is placed under an inert gas on the anode side of the light emitting layer so as to be in contact with the light emitting layer.
  • a state in which a metal oxide semiconductor film formed by sputtering or vapor deposition and a material obtained by pressurizing and solidifying the metal oxide are added to the inert gas and a first gas for oxidizing atmosphere is added.
  • a metal oxide semiconductor film formed by sputtering or vapor deposition and a material obtained by pressurizing and solidifying the metal oxide are added to the inert gas and a second gas for reducing atmosphere.
  • any one of a metal oxide semiconductor film formed by sputtering or vapor deposition is provided.
  • the display device of the present invention includes the electroluminescent element as described above.
  • a metal oxide semiconductor film having a relatively large ionization potential energy that can function sufficiently as a hole injection layer or a hole transport layer of a light emitting layer having a large ionization potential energy can be formed by sputtering or vapor deposition.
  • a metal oxide semiconductor film having a relatively large ionization potential energy that can sufficiently function as a hole injection layer or a hole transport layer of a light emitting layer having a large ionization potential energy, and an electroluminescence device having improved light emission efficiency thus, a display device with improved display quality can be realized.
  • XRD X-ray diffraction analysis
  • FIG. 15 is a diagram showing an EL device of still another embodiment of the present invention shown in FIG. 14 with improved luminous efficiency.
  • a metal oxide semiconductor film is formed by sputtering using a CuAlO 2 metal oxide having a specific resistance value of 1.0 ⁇ 10 6 ⁇ cm or less in a pressurized and solidified state.
  • the metal oxide semiconductor film is used for an EL element.
  • the present invention is not limited to this, and the metal oxide semiconductor film is formed using a vapor deposition method other than the sputtering method.
  • this metal oxide semiconductor film can be applied to devices other than EL elements.
  • FIG. 1 is a diagram for explaining a manufacturing process of a CuAlO 2 metal oxide formed by using wet mixing.
  • each powder of copper oxide (purity: 4N, particle size: 5 ⁇ m) and aluminum oxide (purity: 4N, particle size: 0.2 ⁇ m) is weighed so that the atomic ratio of Cu and Al elements is 1: 1. (S1).
  • CuO (79.545 g / mol) is used as the copper oxide, but Cu 2 O (143.09 g / mol) may be used, and the atomic ratio of Cu and Al element is 1: If they can be weighed so as to be 1, these may be mixed and used.
  • Al 2 O 3 (101.96 g / mol) was used.
  • zirconia balls having a diameter of 5 mm are used for wet mixing, but the material and size of the balls are not limited to this, and can be selected as appropriate.
  • the mixed powder is put into an alumina crucible, fired at 1100 ° C. for 5 hours under an inert gas (for example, Ar gas) (S3), and then the above-mentioned ball mill is used again until the particle size becomes about 100 ⁇ m.
  • an inert gas for example, Ar gas
  • S4 CuAlO 2 crystal powder (CuAlO 2 metal oxide) was obtained (S5).
  • baking is performed at 1100 ° C. for 5 hours under an inert gas (for example, Ar gas), but the baking may be performed in a reducing atmosphere other than the inert gas.
  • an inert gas for example, Ar gas
  • the temperature and time may be 900 degrees or more, and the time is not particularly limited.
  • the inert gas may be N 2 gas or a mixed gas of these inert gases, and the type thereof is not particularly limited.
  • the reducing atmosphere is a reducing atmosphere in an inert gas such as a mixed gas in which H 2 gas is mixed in Ar gas or a mixed gas in which H 2 gas is mixed in N 2 gas.
  • an inert gas such as a mixed gas in which H 2 gas is mixed in Ar gas or a mixed gas in which H 2 gas is mixed in N 2 gas.
  • H 2 gas can be given as the second gas, but the second gas is not limited thereto.
  • the type of gas to be mixed also is not limited to H 2 gas.
  • H 2 gas is mixed in N 2 gas is preferably mixed in the following pyrophoric concentration of H 2 gas, for example, 3% ccm mixture of H 2 gas to N 2 gas It is preferable to use the mixed gas.
  • FIG. 3B is a diagram showing the result of X-ray diffraction analysis (XRD) of the CuAlO 2 crystal powder (Cu valence in the crystal: +1) obtained as described above.
  • XRD X-ray diffraction analysis
  • FIG. 2 is a diagram for explaining a manufacturing process of a CuAlO 2 metal oxide formed using conventional dry mixing.
  • the mixed powder is put into an alumina crucible, fired at 1100 ° C. for 5 hours under an inert gas (for example, Ar gas) (S23), and then the above-mentioned ball mill is used again until the particle size becomes about 100 ⁇ m.
  • an inert gas for example, Ar gas
  • S24 CuAlO 2 crystal powder partially containing CuAl 2 O 4 crystals was obtained (S25).
  • FIG. 3A shows the result of X-ray diffraction analysis (XRD) of CuAlO 2 crystal powder partially containing CuAl 2 O 4 crystals (Cu valence in crystal: +2) obtained as described above.
  • XRD X-ray diffraction analysis
  • Figure 5 is a CuAlO 2 crystal powder formed utilizing a wet mixture (CuAlO 2 metal oxide), and CuAlO 2 crystals powder containing partially CuAl 2 O 4 crystals formed using the dry mixing, It is a figure which shows the result of producing the target material for sputtering, and measuring the specific resistance value of these target materials, changing the pressure at the time of pressurization solidification processing.
  • the pressure during the pressure solidification treatment is 200 to 600 kg.
  • the specific resistance value is 1.0 ⁇ 10 6 ⁇ cm or less, and CuAlO 2 crystal powder partially including CuAl 2 O 4 crystals formed using dry mixing is used. This is lower than the specific resistance value of the target material produced by pressure solidification treatment at the same pressure.
  • the conductivity of the target material prepared using CuAlO 2 crystal powder (CuAlO 2 metal oxide) formed using wet mixing is CuAl 2 O 4 crystal formed using dry mixing.
  • the conductivity of the produced target material is higher.
  • a metal oxide semiconductor film having a relatively large ionization potential energy that can sufficiently function as a hole injection layer or a hole transport layer of a light emitting layer having a large ionization potential energy cannot be formed.
  • the metal oxide semiconductor film may be formed by vapor deposition.
  • FIG. 6 shows sputtering conditions for a metal oxide semiconductor film formed by sputtering using a target material prepared using CuAlO 2 crystal powder (CuAlO 2 metal oxide) formed by wet mixing. It is a figure which shows the thin film characteristic for every.
  • the sample film 1 is a case where sputtering is performed under an inert gas (Ar gas), and the sample film 2 is formed in an inert gas (Ar gas) in an oxidizing atmosphere. Sputtering is performed in an environment where O 2 gas flows as 10% ccm.
  • the case where O 2 gas is used as the first gas has been described as an example.
  • the first gas is limited to O 2 gas. There is no.
  • the film formation temperature is performed without heating the heater.
  • both of the sample films 1 and 2 show P-type semiconductor characteristics, but the specific resistance value of the sample film 1 that is sputtered under an inert gas (Ar gas). However, it is 1/100 lower than that of the sample film 2 on which sputtering is performed in an environment where 10% ccm of O 2 gas flows into an inert gas (Ar gas).
  • FIG. 7 is a diagram showing the results of X-ray diffraction analysis (XRD) of the sample films 1 and 2.
  • FIG. 7A shows the result of X-ray diffraction analysis (XRD) of the sample film 1.
  • XRD X-ray diffraction analysis
  • FIG. 7B shows the result of X-ray diffraction analysis (XRD) of the sample film 2.
  • XRD X-ray diffraction analysis
  • the specific resistance value of the metal oxide semiconductor film can be adjusted by changing the sputtering conditions.
  • the reducing atmosphere under the sputtering conditions is the same as the reducing atmosphere described in the first embodiment, and the reducing atmosphere is, for example, a mixed gas in which H 2 gas is mixed with Ar gas or N 2 gas.
  • a mixed gas in which H 2 gas is mixed with Ar gas or N 2 gas is, for example, a mixed gas in which H 2 gas is mixed with Ar gas or N 2 gas.
  • the type of gas to be mixed also is not limited to H 2 gas.
  • H 2 gas is mixed in N 2 gas is preferably mixed in the following pyrophoric concentration of H 2 gas, for example, 3% ccm mixture of H 2 gas to N 2 gas It is preferable to use the mixed gas.
  • the specific resistance value is 0.0344 ⁇ cm.
  • Ar atmosphere + O 2 gas inflow an atmosphere to form a metal oxide semiconductor film
  • the specific resistance value becomes larger than 0.0344 ⁇ cm, and a reducing atmosphere (Ar
  • a metal oxide semiconductor film is formed (in the case of the sample film 3) by performing sputtering under an atmosphere + H 2 gas inflow, the specific resistance value is smaller than 0.0344 ⁇ cm.
  • a metal oxide semiconductor film having different film characteristics such as a specific resistance can be easily formed by changing sputtering conditions.
  • FIG. 9 is a diagram for explaining a case where metal oxide semiconductor films having different specific resistance values in the film thickness direction are formed.
  • sputtering was performed under a reducing atmosphere (Ar atmosphere + H 2 gas inflow) to form a metal oxide semiconductor film (sample film 3) (S8).
  • the sample films 1 and 2 can be used in addition to the sample film 3, but in this embodiment, the metal oxide semiconductor film having a layer having a specific resistance value smaller than 0.0344 ⁇ cm. In order to form the sample film 3, the sample film 3 is used.
  • examples of the oxidation treatment include laser annealing in an oxidizing atmosphere and O 2 plasma treatment, but are not limited thereto.
  • the film thickness of the metal oxide semiconductor film (sample film 3) can be determined as appropriate depending on the type of oxidation treatment and the treatment time.
  • the intermediate layer has a specific resistance value (0.01 to 10 ⁇ cm) that can be used as a hole injection layer in an EL element, and the lowermost layer is a level that can be used as an anode layer in the EL element. Which is less than 0.01 ⁇ cm (S10).
  • the metal oxide semiconductor film (sample film 3) is oxidized is described in this embodiment, a reduction process is performed instead of the oxidation process, so that the metal oxide semiconductor film ( The conductivity and P-type characteristics of the sample film 3) can be improved, and metal oxide semiconductor films having different specific resistance values in the film thickness direction can also be formed.
  • Examples of the reduction treatment include laser annealing treatment in a reducing atmosphere.
  • the reducing atmosphere is, for example, a mixed gas in which H 2 gas is mixed with Ar gas or N 2 gas.
  • An example in which H 2 gas is mixed with an inert gas such as a mixed gas in which H 2 gas is mixed can be given, but is not limited thereto.
  • the type of gas to be mixed also is not limited to H 2 gas.
  • H 2 gas is mixed in N 2 gas is preferably mixed in the following pyrophoric concentration of H 2 gas, for example, 3% ccm mixture of H 2 gas to N 2 gas It is preferable to use the mixed gas.
  • FIG. 10 is a diagram for explaining a case where the metal oxide semiconductor film (sample film 2) is partially oxidized to form an insulating film only in a predetermined region.
  • the sample film 2 having a relatively high specific resistance is used as the metal oxide semiconductor film in order to partially oxidize and form an insulating film only in a predetermined region.
  • the sample films 1 and 3 described above may be used.
  • sputtering was performed under an oxidizing atmosphere (Ar atmosphere + O 2 gas inflow) to form the sample film 2 as a metal oxide semiconductor film (S8).
  • the film thickness of the metal oxide semiconductor film (sample film 2) can be determined as appropriate depending on the type of oxidation treatment and the treatment time.
  • sample film 2 Since the conductivity and P-type characteristics of the metal oxide semiconductor film (sample film 2) are reduced by laser annealing or O 2 plasma treatment in an oxidizing atmosphere, the resistance value of a predetermined region of the sample film 2 is increased, An insulating film is formed (S11).
  • a metal oxide semiconductor film is formed by sputtering using a target material prepared using CuAlO 2 crystal powder (CuAlO 2 metal oxide) formed using wet mixing.
  • sputtering is performed under different sputtering conditions.
  • oxidation treatment or reduction treatment is performed to form metal oxide semiconductor films having different specific resistance values in the film thickness direction. A case will be described in which metal oxide semiconductor films having different specific resistance values are stacked and metal oxide semiconductor films having different specific resistance values in the film thickness direction are formed.
  • FIG. 11 illustrates a case in which metal oxide semiconductor films that are sputtered under different sputtering conditions and have different specific resistance values are stacked, and metal oxide semiconductor films having different specific resistance values are formed in the film thickness direction.
  • sputtering was performed under a reducing atmosphere (Ar atmosphere + H 2 gas inflow) to form a sample film 3 having a specific resistance value smaller than 0.0344 ⁇ cm, which was the lowest layer (S12).
  • metal oxide semiconductor films having different specific resistance values in the film thickness direction can be formed, and the lowermost layer (sample film 3) can be used as an anode layer in an EL element.
  • the specific resistance value of the intermediate layer (sample film 1) is 0.0344 ⁇ cm, which is a level that can be used as a hole injection layer in an EL element (0.01).
  • the uppermost layer (sample film 2) has a specific resistance value (10 to 100000 ⁇ cm) that is a level that can be used as a hole transport layer in an EL element.
  • An EL element including a film and a display device including the EL element will be described.
  • ionization potentials such as phosphorescent light emitting materials and quantum dot materials (nano-sized inorganic light emitting materials) that have recently started to be applied as light emitting layers in the EL element field and can realize deeper blue light emission.
  • quantum dot materials nano-sized inorganic light emitting materials
  • Examples of the quantum dot material that is one of the light emitting layers having a large ionization potential energy include CdSe and ZnS II-VI group compounds. In such a quantum dot material, for each color of R, G, B Only its size is different.
  • Examples of phosphorescent materials that can realize deeper blue light emission include oxadiazole dimer dyes (Bis-DAPOXP), spiro compounds (2, 2 ′, 7 , 7'-tetrakis (2,2'-diphenylvinyl) spiro-9,9'-bifluorene (Spiro-DPVBi), Spiro-6P), triarylamine compounds, bis (styryl) amine (4,4'-bis (2,2′diphenylvinyl) -1,1′-biphenyl (DPVBi), bis [2- (4,6-difluorophenyl) pyridinate-N, C2 ′] iridium picolinate (Flrpic), CzTT, anthracene, tetra Phenylbutadiene (TPB), pentaphenylcyclopentadiene (PPC)
  • oxadiazole dimer dyes Bis-DAPOXP
  • Such a light-emitting layer having a large ionization potential energy preferably has an ionization potential energy of 6.1 eV or more in consideration of color purity with ⁇ of about 450 nm or less.
  • FIG. 12 is a diagram for explaining the reason why it is difficult to inject hole carriers in a conventional EL device having a light emitting layer having a large ionization potential energy.
  • the EL element when the EL element is provided with a quantum dot material (QD) made of a II-VI group compound of CdSe or ZnS as a light emitting layer, such a light emitting layer has an ionization potential energy. Because of its large size, hole carriers are not easily injected from the conventional hole transport layer having a relatively low ionization potential energy, and the luminous efficiency of the EL element is low.
  • QD quantum dot material
  • the same problem occurs when the EL element is provided with a phosphorescent material capable of realizing deeper blue light emission as the light emitting layer.
  • FIG. 13 shows a metal oxide semiconductor in which a specific hole transport layer having a relatively low ionization potential energy is sputtered in an oxidizing atmosphere (Ar atmosphere + O 2 gas inflow) to obtain a specific resistance value (10 to 100,000 ⁇ cm). It is a figure which shows the EL element replaced with the film
  • the hole transport layer provided in the EL element of the present embodiment has a relatively high ionization potential energy, even when combined with a light emitting layer having a large ionization potential energy, the hole carriers are It is injected smoothly and the luminous efficiency of the EL element can be increased.
  • the hole transport layer provided in the EL element of the present embodiment can also be obtained by forming these sample films 1 and 3 and then oxidizing these films.
  • FIG. 14 shows metal oxidation by sputtering using a target material prepared using CuAlO 2 crystal powder (CuAlO 2 metal oxide) formed by using the wet mixing already described in the third embodiment.
  • a target material prepared using CuAlO 2 crystal powder (CuAlO 2 metal oxide) formed by using the wet mixing already described in the third embodiment.
  • an anode, a hole injection layer, and a hole transport are formed using a method of forming a metal oxide semiconductor film having a specific resistance value different in a film thickness direction by performing an oxidation treatment after forming a physical semiconductor film. It is a figure for demonstrating the case where a layer is formed.
  • sputtering is performed on a glass substrate 1 under a reducing atmosphere (Ar atmosphere + H 2 gas inflow), and a sheet resistance value is less than 1 k ⁇ / ⁇ (low resistance state: P + ).
  • An oxide semiconductor film 2 (sample film 3) was formed.
  • the specific resistance value (10 to 100000 ⁇ cm) and the sheet resistance value were 10 k ⁇ / ⁇ or more, which is a level that can be used as a hole transport layer in an EL device, and the hole transport layer was formed.
  • the intermediate layer was in a medium resistance state with a specific resistance value (0.01 to 10 ⁇ cm), which is a level that can be used as a hole injection layer in an EL element, and a hole injection layer could be formed.
  • an anode layer having a level of less than 0.01 ⁇ cm and a sheet resistance value of less than 1 k ⁇ / ⁇ that can be used as an anode layer in an EL element could be formed.
  • the anode layer, the hole injection layer, and the hole transport layer can be collectively deposited.
  • the hole transport layer has a relatively large ionization potential energy. It is a figure which shows that a hole carrier is smoothly inject
  • FIG. 16 shows the luminous efficiency of the EL device provided with the conventional hole transport layer having a relatively low ionization potential energy and the EL device according to the present embodiment provided with the hole transport layer having a relatively large ionization potential energy.
  • the EL device of this embodiment provided with a hole transport layer having a relatively large ionization potential energy has high luminous efficiency.
  • FIG. 17 is a diagram showing a schematic configuration of the EL element of the present embodiment.
  • the EL element 10 includes an anode 2 (or a transparent electrode ITO), a hole injection / transport layer 3, a light emitting layer 4, and an electron injection layer 5 on a glass substrate 1. And the cathode 6 are laminated in order.
  • Such a display device including the EL element 10 having high light emission efficiency can realize improvement in display quality.
  • the metal oxide of the present invention it is preferable to show only a crystalline peak based on the CuAlO 2 composition in the X-ray diffraction analysis.
  • the crystallinity peak based on the CuAl 2 O 4 composition is not shown in the X-ray diffraction analysis.
  • the metal oxide obtained by pulverizing the mixed powder obtained by dry-mixing the copper oxide and the aluminum oxide, which is a conventional method, after heat treatment under an inert gas is a factor that increases the specific resistance value.
  • CuAlO 2 containing certain CuAl 2 O 4 is likely to be produced, but a mixed powder obtained by wet-mixing the copper oxide and the aluminum oxide while being pulverized in the presence of a solvent was heat-treated under an inert gas. Later, the metal oxide of the present invention obtained by pulverization is easily crystallized into CuAlO 2 during the heat treatment under the above inert gas, so that CuAl 2 O 4 which is a factor for increasing the specific resistance value is increased. The contained CuAlO 2 is hardly generated.
  • An oxide semiconductor film can be formed.
  • the metal oxide semiconductor film of the present invention is obtained by sputtering or evaporating a material obtained by pressurizing and solidifying the metal oxide in a state where a first gas that is an oxidizing atmosphere is added to the inert gas. It may be formed.
  • Sputtering or vapor deposition is performed in a state where the first gas that is an oxidizing atmosphere is added to the inert gas, thereby forming a metal oxide semiconductor film that is controlled in a direction in which the ionization potential energy is reduced. can do.
  • the metal oxide semiconductor film of the present invention is obtained by sputtering or evaporating a material obtained by solidifying the above metal oxide under pressure in a state where a second gas serving as a reducing atmosphere is added to the inert gas. It may be formed.
  • the metal oxide semiconductor film of the present invention may be formed so as to have different specific resistance values in the film thickness direction by performing oxidation treatment or reduction treatment.
  • the metal oxide semiconductor film formed by sputtering or vapor deposition is subjected to oxidation treatment or reduction treatment, and can be formed so that the specific resistance value is different in the film thickness direction. Metal oxide semiconductor films having different specific resistance values can be formed relatively easily.
  • the metal oxide semiconductor film of the present invention may be oxidized in a predetermined region to increase the specific resistance value of the predetermined region, thereby forming an insulating region.
  • the metal oxide semiconductor film formed by sputtering or evaporation can be oxidized in a predetermined region to increase the specific resistance value of the predetermined region and form an insulating region. Compared to the case where a resist or the like is used, the insulating region can be formed relatively easily.
  • the oxidation treatment performed on the metal oxide semiconductor film of the present invention may be either laser annealing treatment or oxygen plasma treatment in an oxygen atmosphere.
  • the metal oxide semiconductor film can be locally oxidized.
  • the metal oxide semiconductor film formed so as to have different specific resistance values is obtained by sputtering or evaporating a material obtained by solidifying the metal oxide under pressure under an inert gas.
  • Sputtering or vapor deposition of the metal oxide semiconductor film formed and the material obtained by pressurizing and solidifying the metal oxide in a state where a first gas that is an oxidizing atmosphere is added to the inert gas.
  • a second gas serving as a reducing atmosphere is added to the inert gas
  • the metal oxide semiconductor film formed and the material obtained by pressurizing and solidifying the metal oxide are sputtered or
  • a metal oxide semiconductor film formed by vapor deposition may be stacked.
  • the metal oxide semiconductor film formed so that the specific resistance value differs in the film thickness direction without performing oxidation treatment or reduction treatment on the metal oxide semiconductor film formed by sputtering or evaporation. Can be formed.
  • the light emitting layer has an ionization potential energy of 6.1 eV or more, and the material obtained by pressurizing and solidifying the metal oxide so as to be in contact with the light emitting layer is the inert material. It is preferable that a metal oxide semiconductor film formed by sputtering or vapor deposition in a state where a second gas serving as a reducing atmosphere is added to the gas.
  • the electroluminescent device of the present invention is provided with a light emitting layer having a relatively large ionization potential energy of 6.1 eV or more, and can be sufficiently functioned as a hole injection layer or a hole transport layer of the light emitting layer.
  • a metal oxide semiconductor film having a large ionization potential energy in a state where the ionization potential energy sputtered or deposited is further increased in a state where the second gas serving as a reducing atmosphere is added to the inert gas. Since the controlled metal oxide semiconductor film is provided, the light emission efficiency can be further improved.
  • the light emitting layer has an ionization potential energy of 6.1 eV or more, and in the metal oxide semiconductor film formed so that the specific resistance value is different in the film thickness direction,
  • the layer with the highest specific resistance value is formed as a hole transport layer so as to be in contact with the light emitting layer, and the layer with the lowest specific resistance value is formed as the anode, and the specific resistance is
  • the layer having an intermediate value is preferably formed as a hole injection layer between the anode and the hole transport layer.
  • each layer of the metal oxide semiconductor film formed so as to have different specific resistance values in the film thickness direction is used as a hole transport layer, an anode, and a hole injection layer. Therefore, the hole transport layer, the anode, and the hole injection layer can be formed relatively easily.
  • the present invention can be suitably used for an electroluminescent element and a display device provided with a metal oxide semiconductor film.

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Abstract

A metal oxide according to the present invention is produced from a copper oxide and an aluminum oxide which are accurately weighted so that the atomic ratio of a Cu element to an Al element becomes 1:1, and contains a Cu element and an Al element. The metal oxide is characterized by being produced by heating a mixed powder, which is prepared by mixing the copper oxide with the aluminum oxide in a wet mode in the presence of a solvent while milling, under an inert gas atmosphere or a reductive atmosphere at 900˚C or higher and then milling the heated product, and is also characterized by having a specific resistance value of 1.0 × 106 Ωcm or less when being solidified by applying a pressure. The present invention provides an EL element (10) having improved luminous efficiency by providing a hole injection/transport layer (3) having a relatively high ionization potential energy on the anode (2) side of a light-emitting layer (4) having a relatively high ionization potential energy using the metal oxide.

Description

金属酸化物、金属酸化物半導体膜、エレクトロルミネセンス素子および表示装置Metal oxide, metal oxide semiconductor film, electroluminescence element, and display device
　本発明は、金属酸化物をスパッタリングまたは、蒸着させて形成した金属酸化物半導体膜を備えたエレクトロルミネセンス素子および表示装置に関するものである。 The present invention relates to an electroluminescence element and a display device including a metal oxide semiconductor film formed by sputtering or vapor deposition of metal oxide.
　近年、半導体素子や半導体素子を備えた表示装置の分野においては、酸化物半導体層（例えば、ＩｎＧａＺｎＯｘ酸化物半導体層）が注目を浴びており、このような酸化物半導体層を用いることにより、半導体素子の特性を大幅に改善でき、表示装置の表示品位の向上も実現されている。 In recent years, oxide semiconductor layers (eg, InGaZnOx oxide semiconductor layers) have attracted attention in the field of semiconductor elements and display devices including semiconductor elements. By using such oxide semiconductor layers, semiconductors can be obtained. The characteristics of the element can be greatly improved, and the display quality of the display device is also improved.
　一方で、例えば、エレクトロルミネセンス素子（以下、ＥＬ素子と称する）の分野において、正孔注入層や正孔輸送層としての適用が活発に検討されているｐ型半導体特性を示す半導体層として、酸化物半導体層を用いることが検討されている。 On the other hand, for example, in the field of electroluminescence elements (hereinafter referred to as EL elements), as a semiconductor layer exhibiting p-type semiconductor characteristics that are being actively studied as a hole injection layer and a hole transport layer, The use of an oxide semiconductor layer has been studied.
　従来においては、ｐ型半導体特性を示す半導体層としては、例えば、特許文献１に記載されているように、ＬａＣｕＯＳ化合物などの硫化物も検討されていたが、レアメタルである、Ｌａ（ランタン）が用いられており、材料コストが高いことや、硫化物の不安定性（耐湿性が低い）の要因から、量産プロセスへの適応が困難であったため、ＭｏＯｘやＶｏｘＯｙや耐湿性（材料の安定性）が高く、コストの安さ（埋蔵量の多い）という観点からＣｕＡｌＯ２などの酸化物半導体層が注目されるようになった。 Conventionally, as a semiconductor layer exhibiting p-type semiconductor characteristics, for example, as described in Patent Document 1, sulfides such as LaCuOS compounds have been studied. However, La (lanthanum) which is a rare metal is used. It is used, higher material cost and, because the cause of instability of the sulfide (low moisture resistance), it was difficult to adapt to the mass production process, MoO x and Vo x O y and moisture resistance (material From the viewpoint of high stability) and low cost (a large amount of reserves), an oxide semiconductor layer such as CuAlO 2 has attracted attention.
日本国公開特許公報「特開２００６－９３６１９号公報（２００６年４月６日公開）」Japanese Patent Publication “Japanese Patent Laid-Open No. 2006-93619” (published on April 6, 2006)
　しかしながら、ＭｏＯｘやＶｏｘＯｙや従来の方法で形成されたＣｕＡｌ２Ｏ４が含有されたＣｕＡｌＯ２などの酸化物半導体層は、以下に示す理由から、ＥＬ素子分野において、正孔注入層や正孔輸送層として好適に用いることは困難であった。 However, an oxide semiconductor layer such as MoO x , Vo x O y, or CuAlO 2 containing CuAl 2 O 4 formed by a conventional method is used as a hole injection layer in the EL device field for the following reasons. It was difficult to use it suitably as a hole transport layer.
　近年、ＥＬ素子分野においては、発光層として、より深い青色発光を実現し得る燐光発光材料や量子ドット材料などのイオン化ポテンシャルエネルギー（イオン化ポテンシャルともいう）の大きな発光層が適用され始めているが、上記ＭｏＯｘやＶｏｘＯｙや従来の乾式混合で形成されたＣｕＡｌ２Ｏ４が含有されたＣｕＡｌＯ２などの酸化物半導体層は、比較的イオン化ポテンシャルエネルギーが小さいので、このようなイオン化ポテンシャルエネルギーの大きな発光層の正孔注入層や正孔輸送層として、十分に機能しないという問題がある。 In recent years, in the EL element field, a light emitting layer having a large ionization potential energy (also referred to as ionization potential) such as a phosphorescent light emitting material or a quantum dot material capable of realizing deeper blue light emission has begun to be applied. Since an oxide semiconductor layer such as MoO x , Vo x O y, or CuAlO 2 containing CuAl 2 O 4 formed by conventional dry mixing has a relatively small ionization potential energy, such ionization potential energy is low. There is a problem that it does not function sufficiently as a hole injection layer or a hole transport layer of a large light emitting layer.
　本発明は、上記の問題点に鑑みてなされたものであり、スパッタリングまたは、蒸着により、イオン化ポテンシャルエネルギーの大きな発光層の正孔注入層や正孔輸送層として、十分に機能できる比較的イオン化ポテンシャルエネルギーが大きい金属酸化物半導体膜を形成できる金属酸化物と、イオン化ポテンシャルエネルギーの大きな発光層の正孔注入層や正孔輸送層として、十分に機能できる比較的イオン化ポテンシャルエネルギーが大きい金属酸化物半導体膜と、発光効率が向上されたエレクトロルミネセンス素子と、表示品位の向上された表示装置と、を提供することを目的とする。 The present invention has been made in view of the above problems, and is a relatively ionization potential that can sufficiently function as a hole injection layer or a hole transport layer of a light emitting layer having a large ionization potential energy by sputtering or vapor deposition. A metal oxide semiconductor capable of forming a metal oxide semiconductor film having a large energy and a metal oxide semiconductor having a relatively large ionization potential energy that can sufficiently function as a hole injection layer or a hole transport layer of a light emitting layer having a large ionization potential energy. An object is to provide a film, an electroluminescent element with improved luminous efficiency, and a display device with improved display quality.
　本発明の金属酸化物は、上記の課題を解決するために、Ｃｕ元素とＡｌ元素との原子比が１：１となるように秤量された酸化銅と、酸化アルミニウムと、から得られるＣｕ元素とＡｌ元素とを含む金属酸化物であって、溶媒存在下で、上記酸化銅と、上記酸化アルミニウムと、を粉砕しながら湿式混合した混合粉末を、不活性ガス下または、還元雰囲気下で、９００度以上で熱処理した後に、粉砕処理して得られ、かつ、加圧固形化した状態における比抵抗値が１．０×１０６Ωｃｍ以下であることを特徴としている。 In order to solve the above problems, the metal oxide of the present invention is a Cu element obtained from copper oxide and aluminum oxide that are weighed so that the atomic ratio of Cu element to Al element is 1: 1. And a mixed powder obtained by wet-mixing the copper oxide and the aluminum oxide while being pulverized in the presence of a solvent under an inert gas or a reducing atmosphere. It is characterized by being obtained by pulverization after heat treatment at 900 ° C. or more, and having a specific resistance value of 1.0 × 10 6 Ωcm or less in a state of being pressed and solidified.
　上記酸化銅と、上記酸化アルミニウムと、を従来方法である乾式混合した混合粉末を、不活性ガス下で熱処理した後に、粉砕処理して得られた金属酸化物は、加圧固形化した状態における比抵抗値は比較的高い値を示し、このような従来方法で得られる金属酸化物を用いて、スパッタリングや蒸着をしても、イオン化ポテンシャルエネルギーの大きな発光層の正孔注入層や正孔輸送層として、十分に機能できる比較的イオン化ポテンシャルエネルギーが大きい金属酸化物半導体膜を形成することはできない。 The mixed powder obtained by dry-mixing the copper oxide and the aluminum oxide, which is a conventional method, is heat-treated under an inert gas, and then pulverized to obtain a metal oxide in a state of being pressed and solidified. The resistivity value is relatively high. Using a metal oxide obtained by such a conventional method, a hole injection layer or a hole transport layer of a light emitting layer having a large ionization potential energy even when sputtering or vapor deposition is performed. As a layer, a metal oxide semiconductor film having a relatively large ionization potential energy that can function sufficiently cannot be formed.
　一方、本発明の金属酸化物は、溶媒存在下で、上記酸化銅と、上記酸化アルミニウムと、を粉砕しながら湿式混合した混合粉末を、不活性ガス下または、還元雰囲気下で、９００度以上で熱処理した後に、粉砕処理しているため、加圧固形化した状態における比抵抗値が１．０×１０６Ωｃｍ以下を示すので、本発明の金属酸化物を用いて、スパッタリングや蒸着をすれば、イオン化ポテンシャルエネルギーの大きな発光層の正孔注入層や正孔輸送層として、十分に機能できる比較的イオン化ポテンシャルエネルギーが大きい金属酸化物半導体膜を形成することができる。 On the other hand, the metal oxide of the present invention is a mixed powder obtained by wet mixing while pulverizing the copper oxide and the aluminum oxide in the presence of a solvent at 900 ° C. or higher under an inert gas or a reducing atmosphere. Since the specific resistance value in the state of being pressurized and solidified is 1.0 × 10 6 Ωcm or less because it is pulverized after heat treatment with, the sputtering or vapor deposition is performed using the metal oxide of the present invention. For example, a metal oxide semiconductor film having a relatively large ionization potential energy that can sufficiently function as a hole injection layer or a hole transport layer of a light emitting layer having a large ionization potential energy can be formed.
　本発明の金属酸化物半導体膜は、上記の課題を解決するために、上記金属酸化物を加圧固形化した材料を、不活性ガス下で、スパッタリングまたは、蒸着させて形成されたことを特徴としている。 In order to solve the above problems, the metal oxide semiconductor film of the present invention is formed by sputtering or vapor-depositing a material obtained by solidifying the metal oxide under pressure under an inert gas. It is said.
　加圧固形化した状態における比抵抗値が１．０×１０６Ωｃｍ以下を示す金属酸化物を用いて、不活性ガス下で、スパッタリングや蒸着をすれば、イオン化ポテンシャルエネルギーの大きな発光層の正孔注入層や正孔輸送層として、十分に機能できる比較的イオン化ポテンシャルエネルギーが大きい金属酸化物半導体膜を形成することができる。 If sputtering or vapor deposition is performed under inert gas using a metal oxide having a specific resistance value of 1.0 × 10 6 Ωcm or less in a solidified state under pressure, a positive light emitting layer having a large ionization potential energy can be obtained. As the hole injection layer and the hole transport layer, a metal oxide semiconductor film having a relatively large ionization potential energy that can function sufficiently can be formed.
　本発明のエレクトロルミネセンス素子は、上記の課題を解決するために、陽極と陰極とを有し、上記陽極と上記陰極との間に発光層を備えたエレクトロルミネセンス素子であって、上記発光層と接するように、上記発光層の上記陽極側には、上記金属酸化物を加圧固形化した材料を、不活性ガス下で、スパッタリングまたは、蒸着させて形成された金属酸化物半導体膜と、上記金属酸化物を加圧固形化した材料を、上記不活性ガスに、酸化雰囲気とする第１のガスが加えられている状態で、スパッタリングまたは、蒸着させて形成された金属酸化物半導体膜と、上記金属酸化物を加圧固形化した材料を、上記不活性ガスに、還元雰囲気とする第２のガスが加えられている状態で、スパッタリングまたは、蒸着させて形成された金属酸化物半導体膜と、の何れかの膜が備えられていることを特徴としている。 In order to solve the above-described problems, an electroluminescent element of the present invention is an electroluminescent element having an anode and a cathode, and having a light emitting layer between the anode and the cathode. A metal oxide semiconductor film formed by sputtering or evaporating a material obtained by pressurizing and solidifying the metal oxide under an inert gas on the anode side of the light emitting layer so as to be in contact with the layer; A metal oxide semiconductor film formed by sputtering or vapor-depositing a material obtained by pressurizing and solidifying the metal oxide into the inert gas in a state in which a first gas for oxidizing atmosphere is added. And a metal oxide half formed by sputtering or vapor-depositing a material obtained by pressurizing and solidifying the metal oxide in a state where a second gas serving as a reducing atmosphere is added to the inert gas. It is characterized in that the body layer, any of the films is provided.
　本発明のエレクトロルミネセンス素子には、イオン化ポテンシャルエネルギーの大きな発光層の正孔注入層や正孔輸送層として、十分に機能できるようにイオン化ポテンシャルエネルギーを調整できる金属酸化物半導体膜が備えられているので、どのような発光層と組み合わせられても発光効率を向上できる。 The electroluminescent device of the present invention includes a metal oxide semiconductor film that can adjust the ionization potential energy so that it can sufficiently function as a hole injection layer or a hole transport layer of a light emitting layer having a large ionization potential energy. Therefore, the luminous efficiency can be improved regardless of the combination with any light emitting layer.
　本発明の表示装置は、上記の課題を解決するために、上記エレクトロルミネセンス素子を備えたことを特徴としている。 The display device of the present invention is characterized by including the electroluminescence element in order to solve the above-described problems.
　上記表示装置には、発光効率が向上されたエレクトロルミネセンス素子が備えられているので、表示品位を向上できる。 Since the display device includes an electroluminescence element with improved light emission efficiency, display quality can be improved.
　本発明の金属酸化物は、以上のように、溶媒存在下で、上記酸化銅と、上記酸化アルミニウムと、を粉砕しながら湿式混合した混合粉末を、不活性ガス下または、還元雰囲気下で、９００度以上で熱処理した後に、粉砕処理して得られ、かつ、加圧固形化した状態における比抵抗値が１．０×１０６Ωｃｍ以下である。 As described above, the metal oxide of the present invention is a mixed powder obtained by wet mixing while pulverizing the copper oxide and the aluminum oxide in the presence of a solvent under an inert gas or a reducing atmosphere. After the heat treatment at 900 ° C. or more, the specific resistance value obtained by pulverization and solidified under pressure is 1.0 × 10 6 Ωcm or less.
　本発明の金属酸化物半導体膜は、以上のように、上記金属酸化物を加圧固形化した材料を、不活性ガス下で、スパッタリングまたは、蒸着させて形成されている。 As described above, the metal oxide semiconductor film of the present invention is formed by sputtering or vapor-depositing a material obtained by pressurizing and solidifying the metal oxide under an inert gas.
　本発明のエレクトロルミネセンス素子は、以上のように、上記発光層と接するように、上記発光層の上記陽極側には、上記金属酸化物を加圧固形化した材料を、不活性ガス下で、スパッタリングまたは、蒸着させて形成された金属酸化物半導体膜と、上記金属酸化物を加圧固形化した材料を、上記不活性ガスに、酸化雰囲気とする第１のガスが加えられている状態で、スパッタリングまたは、蒸着させて形成された金属酸化物半導体膜と、上記金属酸化物を加圧固形化した材料を、上記不活性ガスに、還元雰囲気とする第２のガスが加えられている状態で、スパッタリングまたは、蒸着させて形成された金属酸化物半導体膜と、の何れかの膜が備えられている。 As described above, in the electroluminescent device of the present invention, a material obtained by pressurizing and solidifying the metal oxide is placed under an inert gas on the anode side of the light emitting layer so as to be in contact with the light emitting layer. A state in which a metal oxide semiconductor film formed by sputtering or vapor deposition and a material obtained by pressurizing and solidifying the metal oxide are added to the inert gas and a first gas for oxidizing atmosphere is added. Then, a metal oxide semiconductor film formed by sputtering or vapor deposition and a material obtained by pressurizing and solidifying the metal oxide are added to the inert gas and a second gas for reducing atmosphere. In this state, any one of a metal oxide semiconductor film formed by sputtering or vapor deposition is provided.
　本発明の表示装置は、以上のように、上記エレクトロルミネセンス素子を備えている。 The display device of the present invention includes the electroluminescent element as described above.
　それゆえ、スパッタリングまたは、蒸着により、イオン化ポテンシャルエネルギーの大きな発光層の正孔注入層や正孔輸送層として、十分に機能できる比較的イオン化ポテンシャルエネルギーが大きい金属酸化物半導体膜を形成できる金属酸化物と、イオン化ポテンシャルエネルギーの大きな発光層の正孔注入層や正孔輸送層として、十分に機能できる比較的イオン化ポテンシャルエネルギーが大きい金属酸化物半導体膜と、発光効率が向上されたエレクトロルミネセンス素子と、表示品位の向上された表示装置と、を実現することができる。 Therefore, a metal oxide semiconductor film having a relatively large ionization potential energy that can function sufficiently as a hole injection layer or a hole transport layer of a light emitting layer having a large ionization potential energy can be formed by sputtering or vapor deposition. A metal oxide semiconductor film having a relatively large ionization potential energy that can sufficiently function as a hole injection layer or a hole transport layer of a light emitting layer having a large ionization potential energy, and an electroluminescence device having improved light emission efficiency Thus, a display device with improved display quality can be realized.
本発明の一実施の形態のＣｕＡｌＯ２金属酸化物の製造プロセスを説明するための図である。It is a diagram for explaining a manufacturing process of CuAlO 2 metal oxide of an embodiment of the present invention. 従来のＣｕＡｌＯ２金属酸化物の製造プロセスを説明するための図である。It is a diagram for explaining a manufacturing process of a conventional CuAlO 2 metal oxide. 本発明の一実施の形態のＣｕＡｌＯ２金属酸化物と従来のＣｕＡｌＯ２金属酸化物とをＸ線回折分析（ＸＲＤ）した結果を示す図である。Is a diagram showing a result of a CuAlO 2 metal oxide of an embodiment of a conventional CuAlO 2 metal oxides have X-ray diffraction analysis (XRD) of the present invention. 金属酸化物を加圧固形化処理し、スパッタリング用ターゲット材を作製する工程を説明する図である。It is a figure explaining the process of carrying out the pressurization solidification process of a metal oxide and producing the target material for sputtering. 金属酸化物の加圧固形化処理時における圧力を変えながら、スパッタリング用ターゲット材を作製し、これらのターゲット材の比抵抗値を測定した結果を示す図である。It is a figure which shows the result of producing the target material for sputtering, changing the pressure at the time of the pressurization solidification process of a metal oxide, and measuring the specific resistance value of these target materials. 湿式混合を利用して形成されたＣｕＡｌＯ２結晶粉末を用いて、作製されたターゲット材を用いて、スパッタリングによって形成される本発明の他の一実施の形態の金属酸化物半導体膜のスパッタリング条件毎の薄膜特性を示す図である。For each sputtering condition of a metal oxide semiconductor film according to another embodiment of the present invention formed by sputtering using a target material prepared using a CuAlO 2 crystal powder formed by wet mixing It is a figure which shows the thin film characteristic. 本発明の他の一実施の形態の金属酸化物半導体膜であるサンプル膜１および２をＸ線回折分析（ＸＲＤ）した結果を示す図である。It is a figure which shows the result of having carried out the X-ray diffraction analysis (XRD) of the sample films | membranes 1 and 2 which are the metal oxide semiconductor films of other one Embodiment of this invention. スパッタリングの条件を変えながら、形成した本発明の他の一実施の形態の金属酸化物半導体膜であるサンプル膜１、２および３の比抵抗値を示す図である。It is a figure which shows the specific resistance value of the sample films 1, 2, and 3 which are the metal oxide semiconductor films of other one Embodiment of this invention formed, changing sputtering conditions. 膜厚方向において、比抵抗値が異なる本発明のさらに他の一実施の形態の金属酸化物半導体膜を形成する場合を説明するための図である。It is a figure for demonstrating the case where the metal oxide semiconductor film of further another embodiment of this invention from which a specific resistance value differs in the film thickness direction is formed. 本発明のさらに他の一実施の形態の金属酸化物半導体膜に対して、部分的に酸化処理を行い、所定領域のみを絶縁膜化する場合を説明するための図である。It is a figure for demonstrating the case where the oxidation process is partially performed with respect to the metal oxide semiconductor film of further another embodiment of this invention, and only a predetermined area | region is made into an insulating film. 異なるスパッタリング条件でスパッタリングされ、その比抵抗値が異なる金属酸化物半導体膜を積層させ、膜厚方向において、本発明のさらに他の一実施の形態の比抵抗値が異なる金属酸化物半導体膜を形成する場合を説明するための図である。Sputtering is performed under different sputtering conditions, and metal oxide semiconductor films having different specific resistance values are stacked to form a metal oxide semiconductor film having different specific resistance values according to another embodiment of the present invention in the film thickness direction. It is a figure for demonstrating the case where it does. イオン化ポテンシャルエネルギーの大きな発光層を備えた従来のＥＬ素子において、正孔キャリアの注入が困難となる理由を説明するための図である。It is a figure for demonstrating why injection | pouring of a hole carrier becomes difficult in the conventional EL element provided with the light emitting layer with big ionization potential energy. 発光効率が向上された本発明のさらに他の一実施の形態のＥＬ素子を示す図である。It is a figure which shows the EL element of further another embodiment of this invention with improved luminous efficiency. 本発明のさらに他の一実施の形態のＥＬ素子において、陽極層、正孔注入層および正孔輸送層を一括して堆積加工する場合を説明する図である。It is a figure explaining the case where the anode layer, the positive hole injection layer, and the positive hole transport layer are collectively deposited in the EL element of further another embodiment of the present invention. 発光効率が向上された図１４に示した本発明のさらに他の一実施の形態のＥＬ素子を示す図である。FIG. 15 is a diagram showing an EL device of still another embodiment of the present invention shown in FIG. 14 with improved luminous efficiency. イオン化ポテンシャルエネルギーが比較的小さい従来の正孔輸送層が備えられたＥＬ素子とイオン化ポテンシャルエネルギーが比較的大きい正孔輸送層が備えられた本実施の形態のＥＬ素子との発光効率を比較した図である。The figure which compared the luminous efficiency of the EL element provided with the conventional hole transport layer with relatively small ionization potential energy, and the EL element of this Embodiment provided with the hole transport layer with relatively large ionization potential energy It is. 本発明の一実施のＥＬ素子の概略構成を示す図である。It is a figure which shows schematic structure of the EL element of one implementation of this invention.
　以下、図面に基づいて本発明の実施の形態について詳しく説明する。ただし、この実施の形態に記載されている構成部品の寸法、材質、形状、その相対配置などはあくまで一実施形態に過ぎず、これらによってこの発明の範囲が限定解釈されるべきではない。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are merely one embodiment, and the scope of the present invention should not be construed as being limited thereto.
　なお、以下の実施の形態においては、加圧固形化した状態における比抵抗値が１．０×１０６Ωｃｍ以下であるＣｕＡｌＯ２金属酸化物を用いて、スパッタリング法で、金属酸化物半導体膜を形成し、この金属酸化物半導体膜をＥＬ素子に用いた例を示しているが、これに限定されることはなく、スパッタリング法以外の蒸着法を用いて、金属酸化物半導体膜を形成することもでき、さらに、この金属酸化物半導体膜は、ＥＬ素子以外にも適用可能である。 In the following embodiments, a metal oxide semiconductor film is formed by sputtering using a CuAlO 2 metal oxide having a specific resistance value of 1.0 × 10 6 Ωcm or less in a pressurized and solidified state. In this example, the metal oxide semiconductor film is used for an EL element. However, the present invention is not limited to this, and the metal oxide semiconductor film is formed using a vapor deposition method other than the sputtering method. In addition, this metal oxide semiconductor film can be applied to devices other than EL elements.
　〔実施の形態１〕
　以下、図１から図５に基づいて、本発明の第１の実施形態について説明する。
（湿式混合を利用して形成されるＣｕＡｌＯ２金属酸化物）
　図１は、湿式混合を利用して形成されるＣｕＡｌＯ２金属酸化物の製造プロセスを説明するための図である。 [Embodiment 1]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
(CuAlO 2 metal oxide formed using wet mixing)
FIG. 1 is a diagram for explaining a manufacturing process of a CuAlO 2 metal oxide formed by using wet mixing.
　先ず、酸化銅（純度：４Ｎ、粒径：５μｍ）、酸化アルミニウム（純度：４Ｎ、粒径：０．２μｍ）の各粉末を、ＣｕとＡｌ元素の原子比が１：１になるように秤量した（Ｓ１）。 First, each powder of copper oxide (purity: 4N, particle size: 5 μm) and aluminum oxide (purity: 4N, particle size: 0.2 μm) is weighed so that the atomic ratio of Cu and Al elements is 1: 1. (S1).
　本実施の形態においては、酸化銅として、ＣｕＯ（７９．５４５ｇ/ｍｏｌ）を用いたが、Ｃｕ２Ｏ（１４３．０９ｇ/ｍｏｌ）を用いてもよく、ＣｕとＡｌ元素の原子比が１：１になるように秤量できるのであれば、これらを混ぜて用いてもよい。 In this embodiment, CuO (79.545 g / mol) is used as the copper oxide, but Cu 2 O (143.09 g / mol) may be used, and the atomic ratio of Cu and Al element is 1: If they can be weighed so as to be 1, these may be mixed and used.
　そして、酸化アルミニウムとしては、Ａｌ２Ｏ３（１０１．９６ｇ/ｍｏｌ）を用いた。 As the aluminum oxide, Al 2 O 3 (101.96 g / mol) was used.
　その後、上記秤量した粉末２００ｇを容量１０００ｍｌのポリ容器に直径５ｍｍのジルコニアボール６００ｇを加え、ボールミル装置にて１８時間湿式混合した（Ｓ２）。なお、本実施の形態においては、溶媒として、アルコールを用いているが、これに限定されることはない。 Thereafter, 200 g of the weighed powder was added to 600 g of zirconia balls having a diameter of 5 mm in a 1000 ml capacity plastic container and wet-mixed for 18 hours in a ball mill apparatus (S2). In this embodiment, alcohol is used as the solvent, but the present invention is not limited to this.
　また、本実施の形態においては、直径５ｍｍのジルコニアボールを用いて、湿式混合をしているが、ボールの材質やサイズはこれに限定されることはなく、適宜選択することができる。 In this embodiment, zirconia balls having a diameter of 5 mm are used for wet mixing, but the material and size of the balls are not limited to this, and can be selected as appropriate.
　それから、混合粉をアルミナるつぼに入れ、不活性ガス（例えば、Ａｒガス）下で、１１００度にて５時間焼成した後（Ｓ３）、１００μｍ程度の粒径となるまで再度上記ボールミルを用いて解砕処理し（Ｓ４）、ＣｕＡｌＯ２結晶粉末（ＣｕＡｌＯ２金属酸化物）を得た（Ｓ５）。 Then, the mixed powder is put into an alumina crucible, fired at 1100 ° C. for 5 hours under an inert gas (for example, Ar gas) (S3), and then the above-mentioned ball mill is used again until the particle size becomes about 100 μm. By crushing (S4), CuAlO 2 crystal powder (CuAlO 2 metal oxide) was obtained (S5).
　なお、本実施の形態においては、不活性ガス（例えば、Ａｒガス）下、１１００度で５時間焼成を行っているが、焼成は、不活性ガス以外に還元雰囲気下で行ってもよく、焼成温度や時間は、ＣｕＡｌＯ２への結晶化が進みやすいのであれば、９００度以上であればよく、時間は特に限定されない。 In this embodiment, baking is performed at 1100 ° C. for 5 hours under an inert gas (for example, Ar gas), but the baking may be performed in a reducing atmosphere other than the inert gas. As long as the crystallization to CuAlO 2 is easy to proceed, the temperature and time may be 900 degrees or more, and the time is not particularly limited.
　なお、上記不活性ガスとは、Ａｒガス以外に、Ｎ２ガスや、これら不活性ガスの混合ガスであってもよく、その種類は特に限定されない。 In addition to the Ar gas, the inert gas may be N 2 gas or a mixed gas of these inert gases, and the type thereof is not particularly limited.
　また、上記還元雰囲気下とは、例えば、ＡｒガスにＨ２ガスが混合された混合ガスやＮ２ガスにＨ２ガスが混合された混合ガスなどのように、不活性ガスに還元雰囲気とする第２のガスとして、Ｈ２ガスが混合された例を挙げることができるが、これに限定されることはない。そして、混合されるガスの種類もＨ２ガスに限定されることはない。 The reducing atmosphere is a reducing atmosphere in an inert gas such as a mixed gas in which H 2 gas is mixed in Ar gas or a mixed gas in which H 2 gas is mixed in N 2 gas. An example in which H 2 gas is mixed can be given as the second gas, but the second gas is not limited thereto. Then, the type of gas to be mixed also is not limited to H 2 gas.
　なお、Ｎ２ガスにＨ２ガスが混合された混合ガスを用いる場合には、Ｈ２ガスの自然発火濃度以下で混合することが好ましく、例えば、Ｎ２ガスにＨ２ガスを３％ｃｃｍ混合した混合ガスを用いることが好ましい。 In the case of using a mixed gas H 2 gas is mixed in N 2 gas is preferably mixed in the following pyrophoric concentration of H 2 gas, for example, 3% ccm mixture of H 2 gas to N 2 gas It is preferable to use the mixed gas.
　図３（ｂ）は、上記のようにして得られたＣｕＡｌＯ２結晶粉末（結晶中のＣｕ価数：＋１）をＸ線回折分析（ＸＲＤ）した結果を示す図である。 FIG. 3B is a diagram showing the result of X-ray diffraction analysis (XRD) of the CuAlO 2 crystal powder (Cu valence in the crystal: +1) obtained as described above.
　図示されているように、ＣｕＡｌＯ２組成に基づく結晶性ピークのみが検出され、ＣｕＡｌ２Ｏ４組成に基づく結晶性ピークは検出されないことから、上述した湿式混合（Ｓ２）を行うことにより、不活性ガス（例えば、Ａｒガス）下で、１１００度にて５時間焼成（Ｓ３）時に、ＣｕＡｌＯ２への結晶化がより進みやすくなる環境を作り出せるものと考えられる。
（乾式混合を利用して形成されるＣｕＡｌＯ２金属酸化物）
　図２は、従来の乾式混合を利用して形成されるＣｕＡｌＯ２金属酸化物の製造プロセスを説明するための図である。 As shown in the drawing, only the crystalline peak based on the CuAlO 2 composition is detected, and the crystalline peak based on the CuAl 2 O 4 composition is not detected. It is considered that an environment in which crystallization into CuAlO 2 is more likely to proceed can be created during firing (S3) at 1100 degrees for 5 hours under a gas (for example, Ar gas).
(CuAlO 2 metal oxide formed using dry mixing)
FIG. 2 is a diagram for explaining a manufacturing process of a CuAlO 2 metal oxide formed using conventional dry mixing.
　上記図１の場合と同様に、先ず、酸化銅（純度：４Ｎ、粒径：５μｍ）、酸化アルミニウム（純度：４Ｎ、粒径：０．２μｍ）の各粉末を、ＣｕとＡｌ元素の原子比が１：１になるように秤量した（Ｓ２１）。 As in the case of FIG. 1 above, first, copper oxide (purity: 4N, particle size: 5 μm), aluminum oxide (purity: 4N, particle size: 0.2 μm) powder, the atomic ratio of Cu and Al element Was weighed so as to be 1: 1 (S21).
　その後、上記秤量した粉末２００ｇを、上述した湿式混合ではなく、溶媒を用いずに、乾式混合（例えば、乳鉢を用いて機械的な掻き混ぜなど）した（Ｓ２２）。 Thereafter, 200 g of the weighed powder was dry-mixed (for example, mechanically agitated using a mortar) without using the above-described wet mixing (S22).
　それから、混合粉をアルミナるつぼに入れ、不活性ガス（例えば、Ａｒガス）下で、１１００度にて５時間焼成した後（Ｓ２３）、１００μｍ程度の粒径となるまで再度上記ボールミルを用いて解砕処理し（Ｓ２４）、ＣｕＡｌ２Ｏ４結晶を一部含むＣｕＡｌＯ２結晶粉末を得た（Ｓ２５）。 Then, the mixed powder is put into an alumina crucible, fired at 1100 ° C. for 5 hours under an inert gas (for example, Ar gas) (S23), and then the above-mentioned ball mill is used again until the particle size becomes about 100 μm. By crushing (S24), CuAlO 2 crystal powder partially containing CuAl 2 O 4 crystals was obtained (S25).
　図３（ａ）は、上記のようにして得られたＣｕＡｌ２Ｏ４結晶（結晶中のＣｕ価数：＋２）を一部含むＣｕＡｌＯ２結晶粉末をＸ線回折分析（ＸＲＤ）した結果を示す図である。 FIG. 3A shows the result of X-ray diffraction analysis (XRD) of CuAlO 2 crystal powder partially containing CuAl 2 O 4 crystals (Cu valence in crystal: +2) obtained as described above. FIG.
　図示されているように、乾式混合を利用して形成されるＣｕＡｌＯ２金属酸化物においては、別相のＣｕＡｌ２Ｏ４組成に基づく結晶性ピークが一部検出されることから、乾式混合（Ｓ２２）を行った場合においては、不活性ガス（例えば、Ａｒガス）下で、１１００度にて５時間焼成（Ｓ２３）時に、ＣｕＡｌＯ２への結晶化がより進みやすくなる環境を作り出せないものと考えられる。
（スパッタリング用ターゲット材の作製）
　図４に図示されているように、湿式混合を利用して形成されたＣｕＡｌＯ２結晶粉末（ＣｕＡｌＯ２金属酸化物）と、ＣｕＡｌ２Ｏ４結晶を一部含むＣｕＡｌＯ２結晶粉末と、のそれぞれを加圧固形化処理（Ｓ６）し、スパッタリング用ターゲット材を作製した（Ｓ７）。 As shown in the drawing, in the CuAlO 2 metal oxide formed by using dry mixing, a crystalline peak based on the CuAl 2 O 4 composition of another phase is partially detected, so that dry mixing (S22 ), It is considered that an environment in which crystallization into CuAlO 2 is more likely to proceed during firing at 1100 ° C. for 5 hours (S23) under an inert gas (for example, Ar gas) cannot be created. It is done.
(Preparation of sputtering target material)
As shown in Figure 4, the CuAlO 2 crystal powder formed utilizing a wet mixture (CuAlO 2 metal oxide), and CuAlO 2 crystals powder containing partially CuAl 2 O 4 crystals, of each A pressure solidification process (S6) was performed to prepare a sputtering target material (S7).
　図５は、湿式混合を利用して形成されたＣｕＡｌＯ２結晶粉末（ＣｕＡｌＯ２金属酸化物）と、乾式混合を利用して形成されるＣｕＡｌ２Ｏ４結晶を一部含むＣｕＡｌＯ２結晶粉末と、を用いて、加圧固形化処理時における圧力を変えながら、スパッタリング用ターゲット材を作製し、これらのターゲット材の比抵抗値を測定した結果を示す図である。 Figure 5 is a CuAlO 2 crystal powder formed utilizing a wet mixture (CuAlO 2 metal oxide), and CuAlO 2 crystals powder containing partially CuAl 2 O 4 crystals formed using the dry mixing, It is a figure which shows the result of producing the target material for sputtering, and measuring the specific resistance value of these target materials, changing the pressure at the time of pressurization solidification processing.
　図示されているように、湿式混合を利用して形成されたＣｕＡｌＯ２結晶粉末（ＣｕＡｌＯ２金属酸化物）を用いて作製されたターゲット材においては、加圧固形化処理時における圧力が２００～６００ｋｇ/ｃｍ２の何れの場合においても、比抵抗値が１．０×１０６Ωｃｍ以下を示し、乾式混合を利用して形成されるＣｕＡｌ２Ｏ４結晶を一部含むＣｕＡｌＯ２結晶粉末を用いて、同じ圧力で加圧固形化処理して作製されたターゲット材の比抵抗値と比べると、低くなっている。 As shown in the drawing, in the target material produced using CuAlO 2 crystal powder (CuAlO 2 metal oxide) formed by wet mixing, the pressure during the pressure solidification treatment is 200 to 600 kg. In any case of / cm 2 , the specific resistance value is 1.0 × 10 6 Ωcm or less, and CuAlO 2 crystal powder partially including CuAl 2 O 4 crystals formed using dry mixing is used. This is lower than the specific resistance value of the target material produced by pressure solidification treatment at the same pressure.
　すなわち、湿式混合を利用して形成されたＣｕＡｌＯ２結晶粉末（ＣｕＡｌＯ２金属酸化物）を用いて、作製されたターゲット材の導電性は、乾式混合を利用して形成されるＣｕＡｌ２Ｏ４結晶を一部含むＣｕＡｌＯ２結晶粉末を用いて、作製されたターゲット材の導電性より高くなっている。 That is, the conductivity of the target material prepared using CuAlO 2 crystal powder (CuAlO 2 metal oxide) formed using wet mixing is CuAl 2 O 4 crystal formed using dry mixing. Using the CuAlO 2 crystal powder that contains a part of, the conductivity of the produced target material is higher.
　以上のように、従来の乾式混合を利用して形成されるＣｕＡｌ２Ｏ４結晶を一部含むＣｕＡｌＯ２結晶粉末を用いて、作製されたターゲット材を用いて、スパッタリングや蒸着をしても、イオン化ポテンシャルエネルギーの大きな発光層の正孔注入層や正孔輸送層として、十分に機能できる比較的イオン化ポテンシャルエネルギーが大きい金属酸化物半導体膜を形成することはできない。 As described above, even if sputtering or vapor deposition is performed using a target material prepared using CuAlO 2 crystal powder partially including CuAl 2 O 4 crystals formed by using conventional dry mixing, A metal oxide semiconductor film having a relatively large ionization potential energy that can sufficiently function as a hole injection layer or a hole transport layer of a light emitting layer having a large ionization potential energy cannot be formed.
　一方、湿式混合を利用して形成されたＣｕＡｌＯ２結晶粉末（ＣｕＡｌＯ２金属酸化物）を用いて、作製されたターゲット材を用いて、スパッタリングや蒸着をした場合には、加圧固形化した状態における比抵抗値が１．０×１０６Ωｃｍ以下を示すので、イオン化ポテンシャルエネルギーの大きな発光層の正孔注入層や正孔輸送層として、十分に機能できる比較的イオン化ポテンシャルエネルギーが大きい金属酸化物半導体膜を形成することができる。 On the other hand, when sputtering or vapor deposition is performed using a target material prepared using CuAlO 2 crystal powder (CuAlO 2 metal oxide) formed by using wet mixing, it is in a state of pressure solidification Since the specific resistance value at 1.0 is 10 × 10 6 Ωcm or less, a metal oxide having a relatively large ionization potential energy that can sufficiently function as a hole injection layer or a hole transport layer of a light emitting layer having a large ionization potential energy A semiconductor film can be formed.
　〔実施の形態２〕
　以下、図６から図８に基づいて、本発明の第２の実施形態について説明する。 [Embodiment 2]
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS.
　以下では、湿式混合を利用して形成されたＣｕＡｌＯ２結晶粉末（ＣｕＡｌＯ２金属酸化物）を用いて、作製されたターゲット材を用いて、スパッタリングによって形成される金属酸化物半導体膜について説明する。 In the following, with reference to CuAlO 2 crystals powder formed by using a wet mixing (CuAlO 2 metal oxide), using the produced target material, described metal oxide semiconductor film formed by sputtering.
　なお、本実施の形態においては、スパッタリングによって、金属酸化物半導体膜を形成する場合について説明するが、金属酸化物半導体膜は蒸着によって、形成されてもよい。 Note that although a case where a metal oxide semiconductor film is formed by sputtering is described in this embodiment, the metal oxide semiconductor film may be formed by vapor deposition.
　図６は、湿式混合を利用して形成されたＣｕＡｌＯ２結晶粉末（ＣｕＡｌＯ２金属酸化物）を用いて、作製されたターゲット材を用いて、スパッタリングによって形成される金属酸化物半導体膜のスパッタリング条件毎の薄膜特性を示す図である。 FIG. 6 shows sputtering conditions for a metal oxide semiconductor film formed by sputtering using a target material prepared using CuAlO 2 crystal powder (CuAlO 2 metal oxide) formed by wet mixing. It is a figure which shows the thin film characteristic for every.
　図示されているように、サンプル膜１は、不活性ガス（Ａｒガス）下で、スパッタリングを行っている場合であり、サンプル膜２は、不活性ガス（Ａｒガス）に、酸化雰囲気とする第１のガスとしてＯ２ガスを１０％ｃｃｍ流入した環境で、スパッタリングを行っている。 As shown in the figure, the sample film 1 is a case where sputtering is performed under an inert gas (Ar gas), and the sample film 2 is formed in an inert gas (Ar gas) in an oxidizing atmosphere. Sputtering is performed in an environment where O 2 gas flows as 10% ccm.
　なお、本実施の形態においては、上記第１のガスとして、Ｏ２ガスを用いた場合を例に挙げて説明しているが、酸化雰囲気を作り出せるのであれば、Ｏ２ガスに限定されることはない。 In this embodiment, the case where O 2 gas is used as the first gas has been described as an example. However, if an oxidizing atmosphere can be created, the first gas is limited to O 2 gas. There is no.
　そして、サンプル膜１および２の何れの場合においても、成膜温度はヒーター加熱なしで行っている。 In either case of the sample films 1 and 2, the film formation temperature is performed without heating the heater.
　図示されているように、サンプル膜１および２の何れもＰ型の半導体特性を示すが、その比抵抗値は、不活性ガス（Ａｒガス）下で、スパッタリングを行っているサンプル膜１の方が、不活性ガス（Ａｒガス）に、Ｏ２ガスを１０％ｃｃｍ流入した環境で、スパッタリングを行っているサンプル膜２より、１/１００と低くなっている。 As shown in the figure, both of the sample films 1 and 2 show P-type semiconductor characteristics, but the specific resistance value of the sample film 1 that is sputtered under an inert gas (Ar gas). However, it is 1/100 lower than that of the sample film 2 on which sputtering is performed in an environment where 10% ccm of O 2 gas flows into an inert gas (Ar gas).
　これは、サンプル膜２の場合は、流入されたＯ２ガスの影響で、Ｃｕ＋がＣｕ２＋＋ｅ-に酸化されたためである。 This is because in the case of the sample film 2, Cu + was oxidized to Cu 2+ + e − due to the influence of the inflowing O 2 gas.
　図７は、サンプル膜１および２をＸ線回折分析（ＸＲＤ）した結果を示す図である。 FIG. 7 is a diagram showing the results of X-ray diffraction analysis (XRD) of the sample films 1 and 2.
　図７（ａ）は、サンプル膜１をＸ線回折分析（ＸＲＤ）した結果を示しており、比較的比抵抗値が低く、導電性が高いサンプル膜１の場合は、金属酸化物半導体膜が非晶質状態（アモルファス状態）で形成されている。 FIG. 7A shows the result of X-ray diffraction analysis (XRD) of the sample film 1. In the case of the sample film 1 having a relatively low specific resistance and high conductivity, the metal oxide semiconductor film is It is formed in an amorphous state (amorphous state).
　一方、図７（ｂ）は、サンプル膜２をＸ線回折分析（ＸＲＤ）した結果を示しており、比較的比抵抗値が高く、導電性が低いサンプル膜２の場合は、一部にＣｕ２Ｏと考えられる結晶相が検出される。 On the other hand, FIG. 7B shows the result of X-ray diffraction analysis (XRD) of the sample film 2. In the case of the sample film 2 having a relatively high specific resistance value and low conductivity, a part of the film is Cu. A crystalline phase believed to be 2 O is detected.
　Ｃｕ＋が比較的Ｏと反応しやすく、結晶化が進行すると、ホール注入性が低下され、キャリア濃度が低下するものと考えられる。 It is considered that Cu + is relatively easy to react with O, and when crystallization proceeds, the hole injection property is lowered and the carrier concentration is lowered.
　以上のように、スパッタリングの条件を変えることにより、金属酸化物半導体膜の比抵抗値を調整することができることがわかった。 As described above, it was found that the specific resistance value of the metal oxide semiconductor film can be adjusted by changing the sputtering conditions.
　そこで、還元雰囲気（Ａｒ雰囲気＋Ｈ２ガス流入）下で、スパッタリングを行い、金属酸化物半導体膜を形成したところ、図８に示すような結果を得ることができた。 Therefore, when a metal oxide semiconductor film was formed by performing sputtering under a reducing atmosphere (Ar atmosphere + H 2 gas inflow), results as shown in FIG. 8 were obtained.
　なお、上記スパッタリングの条件における還元雰囲気も、上記実施の形態１で説明した還元雰囲気と同じであり、還元雰囲気下とは、例えば、ＡｒガスにＨ２ガスが混合された混合ガスやＮ２ガスにＨ２ガスが混合された混合ガスなどのように、不活性ガスにＨ２ガスが混合された例を挙げることができるが、これに限定されることはない。そして、混合されるガスの種類もＨ２ガスに限定されることはない。 Note that the reducing atmosphere under the sputtering conditions is the same as the reducing atmosphere described in the first embodiment, and the reducing atmosphere is, for example, a mixed gas in which H 2 gas is mixed with Ar gas or N 2 gas. An example in which an H 2 gas is mixed with an inert gas, such as a mixed gas in which H 2 gas is mixed, may be mentioned, but is not limited thereto. Then, the type of gas to be mixed also is not limited to H 2 gas.
　また、Ｎ２ガスにＨ２ガスが混合された混合ガスを用いる場合には、Ｈ２ガスの自然発火濃度以下で混合することが好ましく、例えば、Ｎ２ガスにＨ２ガスを３％ｃｃｍ混合した混合ガスを用いることが好ましい。 In the case of using a mixed gas H 2 gas is mixed in N 2 gas is preferably mixed in the following pyrophoric concentration of H 2 gas, for example, 3% ccm mixture of H 2 gas to N 2 gas It is preferable to use the mixed gas.
　図８に図示されているように、Ａｒ雰囲気下で、スパッタリングを行い、金属酸化物半導体膜を形成した場合（サンプル膜１の場合）には、比抵抗値が０．０３４４Ωｃｍとなるが、酸化雰囲気（Ａｒ雰囲気＋Ｏ２ガス流入）下で、スパッタリングを行い、金属酸化物半導体膜を形成した場合（サンプル膜２の場合）には、比抵抗値が０．０３４４Ωｃｍより大きくなり、還元雰囲気（Ａｒ雰囲気＋Ｈ２ガス流入）下で、スパッタリングを行い、金属酸化物半導体膜を形成した場合（サンプル膜３の場合）には、比抵抗値が０．０３４４Ωｃｍより小さくなる。 As shown in FIG. 8, when a metal oxide semiconductor film is formed by sputtering in an Ar atmosphere (in the case of the sample film 1), the specific resistance value is 0.0344 Ωcm. When sputtering is performed under an atmosphere (Ar atmosphere + O 2 gas inflow) to form a metal oxide semiconductor film (in the case of the sample film 2), the specific resistance value becomes larger than 0.0344 Ωcm, and a reducing atmosphere (Ar When a metal oxide semiconductor film is formed (in the case of the sample film 3) by performing sputtering under an atmosphere + H 2 gas inflow, the specific resistance value is smaller than 0.0344 Ωcm.
　このように、本実施の形態の金属酸化物半導体膜は、スパッタリングの条件を変えることにより、比抵抗値などの膜特性の異なる金属酸化物半導体膜を容易に形成することができる。 As described above, in the metal oxide semiconductor film of this embodiment, a metal oxide semiconductor film having different film characteristics such as a specific resistance can be easily formed by changing sputtering conditions.
　〔実施の形態３〕
　以下、図９に基づいて、本発明の第３の実施形態について説明する。 [Embodiment 3]
Hereinafter, a third embodiment of the present invention will be described with reference to FIG.
　以下では、湿式混合を利用して形成されたＣｕＡｌＯ２結晶粉末（ＣｕＡｌＯ２金属酸化物）を用いて、作製されたターゲット材を用いて、スパッタリングによって、金属酸化物半導体膜を形成した後に、酸化処理または、還元処理を行い、膜厚方向において、比抵抗値が異なる金属酸化物半導体膜を形成する場合について説明する。 In the following, after forming a metal oxide semiconductor film by sputtering using a prepared target material using CuAlO 2 crystal powder (CuAlO 2 metal oxide) formed using wet mixing, oxidation is performed. A case where metal oxide semiconductor films having different specific resistance values in the film thickness direction are formed by performing treatment or reduction treatment will be described.
　図９は、膜厚方向において、比抵抗値が異なる金属酸化物半導体膜を形成する場合を説明するための図である。 FIG. 9 is a diagram for explaining a case where metal oxide semiconductor films having different specific resistance values in the film thickness direction are formed.
　図示されているように、本実施の形態においては、先ず、還元雰囲気（Ａｒ雰囲気＋Ｈ２ガス流入）下で、スパッタリングを行い、金属酸化物半導体膜（サンプル膜３）を形成した（Ｓ８）。 As illustrated, in the present embodiment, first, sputtering was performed under a reducing atmosphere (Ar atmosphere + H 2 gas inflow) to form a metal oxide semiconductor film (sample film 3) (S8).
　金属酸化物半導体膜としては、サンプル膜３以外にサンプル膜１および２も用いることができるが、本実施の形態においては、比抵抗値が０．０３４４Ωｃｍより小さくなる層を有する金属酸化物半導体膜を形成するため、サンプル膜３を用いている。 As the metal oxide semiconductor film, the sample films 1 and 2 can be used in addition to the sample film 3, but in this embodiment, the metal oxide semiconductor film having a layer having a specific resistance value smaller than 0.0344 Ωcm. In order to form the sample film 3, the sample film 3 is used.
　それから、金属酸化物半導体膜（サンプル膜３）に対して、酸化雰囲気下で、レーザーアニールまたは、Ｏ２プラズマ処理を行った（Ｓ９）。本実施の形態においては、酸化処理の例として、酸化雰囲気下でのレーザーアニールと、Ｏ２プラズマ処理と、を挙げているがこれに限定されることはない。 Then, laser annealing or O 2 plasma treatment was performed on the metal oxide semiconductor film (sample film 3) in an oxidizing atmosphere (S9). In the present embodiment, examples of the oxidation treatment include laser annealing in an oxidizing atmosphere and O 2 plasma treatment, but are not limited thereto.
　なお、金属酸化物半導体膜（サンプル膜３）の膜厚は、上記酸化処理の種類や処理時間によって、適宜決めることができる。 Note that the film thickness of the metal oxide semiconductor film (sample film 3) can be determined as appropriate depending on the type of oxidation treatment and the treatment time.
　酸化雰囲気下でのレーザーアニールまたは、Ｏ２プラズマ処理によって、金属酸化物半導体膜（サンプル膜３）の導電性やＰ型特性は低下されるが、最上層である処理対象面付近では、その低下が著しく、後述するＥＬ素子における正孔輸送層として用いることが可能なレベルである比抵抗値（１０～１０００００Ωｃｍ）となる。そして、中間層は、ＥＬ素子における正孔注入層として用いることが可能なレベルである比抵抗値（０．０１～１０Ωｃｍ）となり、最下層は、ＥＬ素子における陽極層として用いることが可能なレベルである０．０１Ωｃｍ未満となる（Ｓ１０）。 Laser annealing in an oxidizing atmosphere or O 2 plasma treatment reduces the conductivity and P-type characteristics of the metal oxide semiconductor film (sample film 3), but the reduction is near the top surface to be processed. However, the specific resistance value (10 to 100000 Ωcm), which is a level that can be used as a hole transport layer in an EL element described later, is remarkable. The intermediate layer has a specific resistance value (0.01 to 10 Ωcm) that can be used as a hole injection layer in an EL element, and the lowermost layer is a level that can be used as an anode layer in the EL element. Which is less than 0.01 Ωcm (S10).
　なお、本実施の形態においては、金属酸化物半導体膜（サンプル膜３）に対して、酸化処理をする場合について説明したが、酸化処理の代わりに、還元処理を行い、金属酸化物半導体膜（サンプル膜３）の導電性やＰ型特性は向上させ、膜厚方向において、比抵抗値が異なる金属酸化物半導体膜を形成することもできる。 Note that although the case where the metal oxide semiconductor film (sample film 3) is oxidized is described in this embodiment, a reduction process is performed instead of the oxidation process, so that the metal oxide semiconductor film ( The conductivity and P-type characteristics of the sample film 3) can be improved, and metal oxide semiconductor films having different specific resistance values in the film thickness direction can also be formed.
　上記還元処理とは、例えば、還元雰囲気下でのレーザーアニール処理などを例に挙げることができ、上記還元雰囲気とは、例えば、ＡｒガスにＨ２ガスが混合された混合ガスやＮ２ガスにＨ２ガスが混合された混合ガスなどのように、不活性ガスにＨ２ガスが混合された例を挙げることができるが、これに限定されることはない。そして、混合されるガスの種類もＨ２ガスに限定されることはない。 Examples of the reduction treatment include laser annealing treatment in a reducing atmosphere. The reducing atmosphere is, for example, a mixed gas in which H 2 gas is mixed with Ar gas or N 2 gas. An example in which H 2 gas is mixed with an inert gas such as a mixed gas in which H 2 gas is mixed can be given, but is not limited thereto. Then, the type of gas to be mixed also is not limited to H 2 gas.
　また、Ｎ２ガスにＨ２ガスが混合された混合ガスを用いる場合には、Ｈ２ガスの自然発火濃度以下で混合することが好ましく、例えば、Ｎ２ガスにＨ２ガスを３％ｃｃｍ混合した混合ガスを用いることが好ましい。 In the case of using a mixed gas H 2 gas is mixed in N 2 gas is preferably mixed in the following pyrophoric concentration of H 2 gas, for example, 3% ccm mixture of H 2 gas to N 2 gas It is preferable to use the mixed gas.
　〔実施の形態４〕
　以下、図１０に基づいて、本発明の第４の実施形態について説明する。 [Embodiment 4]
Hereinafter, a fourth embodiment of the present invention will be described with reference to FIG.
　以下では、湿式混合を利用して形成されたＣｕＡｌＯ２結晶粉末（ＣｕＡｌＯ２金属酸化物）を用いて、作製されたターゲット材を用いて、スパッタリングによって、金属酸化物半導体膜を形成した後に、部分的に酸化処理を行い、所定領域のみを絶縁膜化する場合について説明する。 In the following, after forming a metal oxide semiconductor film by sputtering using a target material prepared using CuAlO 2 crystal powder (CuAlO 2 metal oxide) formed using wet mixing, A case will be described in which oxidation treatment is performed to form an insulating film only in a predetermined region.
　図１０は、金属酸化物半導体膜（サンプル膜２）に対して、部分的に酸化処理を行い、所定領域のみを絶縁膜化する場合を説明するための図である。 FIG. 10 is a diagram for explaining a case where the metal oxide semiconductor film (sample film 2) is partially oxidized to form an insulating film only in a predetermined region.
　本実施の形態においては、部分的に酸化処理を行い、所定領域のみを絶縁膜化を行うため、金属酸化物半導体膜として、比較的比抵抗値が高いサンプル膜２を用いているが、これに限定されることはなく、上述したサンプル膜１および３を用いてもよい。 In the present embodiment, the sample film 2 having a relatively high specific resistance is used as the metal oxide semiconductor film in order to partially oxidize and form an insulating film only in a predetermined region. However, the sample films 1 and 3 described above may be used.
　図示されているように、本実施の形態においては、先ず、酸化雰囲気（Ａｒ雰囲気＋Ｏ２ガス流入）下で、スパッタリングを行い、金属酸化物半導体膜として、サンプル膜２を形成した（Ｓ８）。 As shown in the drawing, in the present embodiment, first, sputtering was performed under an oxidizing atmosphere (Ar atmosphere + O 2 gas inflow) to form the sample film 2 as a metal oxide semiconductor film (S8).
　それから、金属酸化物半導体膜（サンプル膜２）の所定領域に対して、部分的に、酸化雰囲気下で、レーザーアニールまたは、Ｏ２プラズマ処理を行った（Ｓ９）。 Then, laser annealing or O 2 plasma treatment was partially performed in an oxidizing atmosphere on a predetermined region of the metal oxide semiconductor film (sample film 2) (S9).
　なお、金属酸化物半導体膜（サンプル膜２）の膜厚は、上記酸化処理の種類や処理時間によって、適宜決めることができる。 Note that the film thickness of the metal oxide semiconductor film (sample film 2) can be determined as appropriate depending on the type of oxidation treatment and the treatment time.
　酸化雰囲気下でのレーザーアニールまたは、Ｏ２プラズマ処理によって、金属酸化物半導体膜（サンプル膜２）の導電性やＰ型特性は低下するので、サンプル膜２の所定領域の抵抗値を上げて、絶縁膜化する（Ｓ１１）。 Since the conductivity and P-type characteristics of the metal oxide semiconductor film (sample film 2) are reduced by laser annealing or O 2 plasma treatment in an oxidizing atmosphere, the resistance value of a predetermined region of the sample film 2 is increased, An insulating film is formed (S11).
　このように、サンプル膜２の所定領域の抵抗値を上げて、絶縁膜化することにより、別途の絶縁膜やフォートレジストなどを用いる場合に比べると、比較的容易に絶縁領域を形成することができる。 As described above, by increasing the resistance value of the predetermined region of the sample film 2 to form an insulating film, it is possible to form the insulating region relatively easily as compared with the case of using a separate insulating film or Fort resist. it can.
　〔実施の形態５〕
　以下、図１１に基づいて、本発明の第５の実施形態について説明する。 [Embodiment 5]
Hereinafter, a fifth embodiment of the present invention will be described with reference to FIG.
　上述した実施の形態３においては、湿式混合を利用して形成されたＣｕＡｌＯ２結晶粉末（ＣｕＡｌＯ２金属酸化物）を用いて、作製されたターゲット材を用いて、スパッタリングによって、金属酸化物半導体膜を形成した後に、酸化処理または、還元処理を行い、膜厚方向において、比抵抗値が異なる金属酸化物半導体膜を形成する場合について説明したが、本実施の形態においては、異なるスパッタリング条件でスパッタリングされ、その比抵抗値が異なる金属酸化物半導体膜を積層させ、膜厚方向において、比抵抗値が異なる金属酸化物半導体膜を形成する場合について説明する。 In Embodiment 3 described above, a metal oxide semiconductor film is formed by sputtering using a target material prepared using CuAlO 2 crystal powder (CuAlO 2 metal oxide) formed using wet mixing. However, in this embodiment, sputtering is performed under different sputtering conditions. However, in this embodiment, oxidation treatment or reduction treatment is performed to form metal oxide semiconductor films having different specific resistance values in the film thickness direction. A case will be described in which metal oxide semiconductor films having different specific resistance values are stacked and metal oxide semiconductor films having different specific resistance values in the film thickness direction are formed.
　図１１は、異なるスパッタリング条件でスパッタリングされ、その比抵抗値が異なる金属酸化物半導体膜を積層させ、膜厚方向において、比抵抗値が異なる金属酸化物半導体膜を形成する場合を説明するための図である。 FIG. 11 illustrates a case in which metal oxide semiconductor films that are sputtered under different sputtering conditions and have different specific resistance values are stacked, and metal oxide semiconductor films having different specific resistance values are formed in the film thickness direction. FIG.
　図示されているように、先ず、還元雰囲気（Ａｒ雰囲気＋Ｈ２ガス流入）下で、スパッタリングを行い、比抵抗値が０．０３４４Ωｃｍより小さいサンプル膜３を形成し、最下層とした（Ｓ１２）。 As shown in the drawing, first, sputtering was performed under a reducing atmosphere (Ar atmosphere + H 2 gas inflow) to form a sample film 3 having a specific resistance value smaller than 0.0344 Ωcm, which was the lowest layer (S12).
　そして、上記サンプル膜３上に、Ａｒ雰囲気下で、スパッタリングを行い、比抵抗値が０．０３４４Ωｃｍとなるサンプル膜１を形成し、中間層とした（Ｓ１３）。 Then, sputtering was performed on the sample film 3 in an Ar atmosphere to form the sample film 1 having a specific resistance value of 0.0344 Ωcm, which was used as an intermediate layer (S13).
　それから、上記サンプル膜１上に、酸化雰囲気（Ａｒ雰囲気＋Ｏ２ガス流入）下で、スパッタリングを行い、比抵抗値が０．０３４４Ωｃｍより大きいサンプル膜２を形成し、最上層とした（Ｓ１４）。 Then, sputtering was performed on the sample film 1 under an oxidizing atmosphere (Ar atmosphere + O 2 gas inflow) to form the sample film 2 having a specific resistance value greater than 0.0344 Ωcm, which was the uppermost layer (S14).
　以上のようにして、膜厚方向において、比抵抗値が異なる金属酸化物半導体膜を形成することができ、上記最下層（サンプル膜３）は、ＥＬ素子における陽極層として用いることが可能なレベルである０．０１Ωｃｍ未満となり、上記中間層（サンプル膜１）は、比抵抗値が０．０３４４Ωｃｍで、ＥＬ素子における正孔注入層として用いることが可能なレベルである比抵抗値（０．０１～１０Ωｃｍ）となり、上記最上層（サンプル膜２）は、ＥＬ素子における正孔輸送層として用いることが可能なレベルである比抵抗値（１０～１０００００Ωｃｍ）となる。 As described above, metal oxide semiconductor films having different specific resistance values in the film thickness direction can be formed, and the lowermost layer (sample film 3) can be used as an anode layer in an EL element. The specific resistance value of the intermediate layer (sample film 1) is 0.0344 Ωcm, which is a level that can be used as a hole injection layer in an EL element (0.01). The uppermost layer (sample film 2) has a specific resistance value (10 to 100000 Ωcm) that is a level that can be used as a hole transport layer in an EL element.
　〔実施の形態６〕
　以下、図１２から図１７に基づいて、本発明の第６の実施形態について説明する。 [Embodiment 6]
Hereinafter, the sixth embodiment of the present invention will be described with reference to FIGS.
　本実施の形態においては、湿式混合を利用して形成されたＣｕＡｌＯ２結晶粉末（ＣｕＡｌＯ２金属酸化物）を用いて、作製されたターゲット材を用いて、スパッタリングによって、形成された金属酸化物半導体膜を備えたＥＬ素子とこのＥＬ素子を備えた表示装置について説明する。 In the present embodiment, a metal oxide semiconductor formed by sputtering using a target material prepared using a CuAlO 2 crystal powder (CuAlO 2 metal oxide) formed using wet mixing. An EL element including a film and a display device including the EL element will be described.
　本実施の形態においては、近年、ＥＬ素子分野において、発光層として、適用され始めている、より深い青色発光を実現し得る燐光発光材料や量子ドット材料（ナノサイズの無機発光材料）などのイオン化ポテンシャルエネルギーの大きな発光層中、量子ドット材料を用いて形成されたＥＬ素子について説明する。 In the present embodiment, ionization potentials such as phosphorescent light emitting materials and quantum dot materials (nano-sized inorganic light emitting materials) that have recently started to be applied as light emitting layers in the EL element field and can realize deeper blue light emission. An EL element formed using a quantum dot material in a light emitting layer having a large energy will be described.
　イオン化ポテンシャルエネルギーの大きな発光層の一つである量子ドット材料としては、ＣｄＳｅやＺｎＳのII－ＶI族化合物を例に挙げることができ、このような量子ドット材料において、Ｒ・Ｇ・Ｂ各色毎にそのサイズのみが異なる。 Examples of the quantum dot material that is one of the light emitting layers having a large ionization potential energy include CdSe and ZnS II-VI group compounds. In such a quantum dot material, for each color of R, G, B Only its size is different.
　そして、もう一つのイオン化ポテンシャルエネルギーの大きな発光層の例であるより深い青色発光を実現し得る燐光発光材料としては、オキサジアゾールダイマー染料（Ｂｉｓ－ＤＡＰＯＸＰ）、スピロ化合物（２，２’，７，７’－テトラキス（２，２’－ジフェニルビニル）スピロ－９，９’－ビフルオレン（Ｓｐｉｒｏ－ＤＰＶＢｉ）、Ｓｐｉｒｏ－６Ｐ）、トリアリールアミン化合物、ビス（スチリル）アミン（４，４’－ビス（２，２’ジフェニルビニル）－１，１’－ビフェニル（ＤＰＶＢｉ）、ビス［２－（４，６－ジフルオロフェニル）ピリジナート－Ｎ，Ｃ２’］イリジウムピコリネート（Ｆｌｒｐｉｃ）、ＣｚＴＴ、アントラセン、テトラフェニルブタジエン（ＴＰＢ）、ペンタフェニルシクロペンタジエン（ＰＰＣＰ）、ＤＳＴ、トリフェニルアミン（ＴＰＡ）、ＯＸＤ－４、ＢＢＯＴ、ＡＺＭ－Ｚｎなどを例に挙げることができる。 Examples of phosphorescent materials that can realize deeper blue light emission, which is another example of a light emitting layer having a large ionization potential energy, include oxadiazole dimer dyes (Bis-DAPOXP), spiro compounds (2, 2 ′, 7 , 7'-tetrakis (2,2'-diphenylvinyl) spiro-9,9'-bifluorene (Spiro-DPVBi), Spiro-6P), triarylamine compounds, bis (styryl) amine (4,4'-bis (2,2′diphenylvinyl) -1,1′-biphenyl (DPVBi), bis [2- (4,6-difluorophenyl) pyridinate-N, C2 ′] iridium picolinate (Flrpic), CzTT, anthracene, tetra Phenylbutadiene (TPB), pentaphenylcyclopentadiene (PPC) ), DST, triphenylamine (TPA), OXD-4, BBOT, and AZM-Zn may be cited as an example.
　このようなイオン化ポテンシャルエネルギーの大きな発光層は、λが４５０ｎｍ程度以下の色純度を考慮すると、そのイオン化ポテンシャルエネルギーは６．１ｅＶ以上であることが好ましい。 Such a light-emitting layer having a large ionization potential energy preferably has an ionization potential energy of 6.1 eV or more in consideration of color purity with λ of about 450 nm or less.
　図１２は、イオン化ポテンシャルエネルギーの大きな発光層を備えた従来のＥＬ素子において、正孔キャリアの注入が困難となる理由を説明するための図である。 FIG. 12 is a diagram for explaining the reason why it is difficult to inject hole carriers in a conventional EL device having a light emitting layer having a large ionization potential energy.
　図示されているように、ＥＬ素子に、発光層として、ＣｄＳｅやＺｎＳのII－ＶI族化合物からなる量子ドット材料（ＱＤ）が備えられている場合、このような発光層は、イオン化ポテンシャルエネルギーが大きいため、イオン化ポテンシャルエネルギーが比較的小さい従来の正孔輸送層からは、正孔キャリアが注入されにくく、ＥＬ素子の発光効率が低く問題となっていた。 As shown in the drawing, when the EL element is provided with a quantum dot material (QD) made of a II-VI group compound of CdSe or ZnS as a light emitting layer, such a light emitting layer has an ionization potential energy. Because of its large size, hole carriers are not easily injected from the conventional hole transport layer having a relatively low ionization potential energy, and the luminous efficiency of the EL element is low.
　図示はしてないが、ＥＬ素子に、発光層として、より深い青色発光を実現し得る燐光発光材料が備えられている場合にも同様の問題が生じる。 Although not shown, the same problem occurs when the EL element is provided with a phosphorescent material capable of realizing deeper blue light emission as the light emitting layer.
　図１３は、イオン化ポテンシャルエネルギーが比較的小さい従来の正孔輸送層を、酸化雰囲気（Ａｒ雰囲気＋Ｏ２ガス流入）下で、スパッタリングを行い、比抵抗値（１０～１０００００Ωｃｍ）となる金属酸化物半導体膜（サンプル膜２）に、置き換えたＥＬ素子を示す図である。 FIG. 13 shows a metal oxide semiconductor in which a specific hole transport layer having a relatively low ionization potential energy is sputtered in an oxidizing atmosphere (Ar atmosphere + O 2 gas inflow) to obtain a specific resistance value (10 to 100,000 Ωcm). It is a figure which shows the EL element replaced with the film | membrane (sample film | membrane 2).
　図示されているように、本実施の形態のＥＬ素子に備えられた正孔輸送層は、イオン化ポテンシャルエネルギーが比較的大きいので、イオン化ポテンシャルエネルギーが大きい発光層と組み合わせられても、正孔キャリアは円滑に注入され、ＥＬ素子の発光効率を高くすることができる。 As shown in the drawing, since the hole transport layer provided in the EL element of the present embodiment has a relatively high ionization potential energy, even when combined with a light emitting layer having a large ionization potential energy, the hole carriers are It is injected smoothly and the luminous efficiency of the EL element can be increased.
　なお、本実施の形態のＥＬ素子に備えられた正孔輸送層は、上述したサンプル膜１および３を形成した後に、これらの膜を酸化処理して得ることもできる。 The hole transport layer provided in the EL element of the present embodiment can also be obtained by forming these sample films 1 and 3 and then oxidizing these films.
　図１４は、実施の形態３で既に説明した湿式混合を利用して形成されたＣｕＡｌＯ２結晶粉末（ＣｕＡｌＯ２金属酸化物）を用いて、作製されたターゲット材を用いて、スパッタリングによって、金属酸化物半導体膜を形成した後に、酸化処理を行い、膜厚方向において、比抵抗値が異なる金属酸化物半導体膜を形成する方法を用いて、ＥＬ素子において、陽極、正孔注入層および正孔輸送層を形成する場合を説明するための図である。 FIG. 14 shows metal oxidation by sputtering using a target material prepared using CuAlO 2 crystal powder (CuAlO 2 metal oxide) formed by using the wet mixing already described in the third embodiment. In the EL element, an anode, a hole injection layer, and a hole transport are formed using a method of forming a metal oxide semiconductor film having a specific resistance value different in a film thickness direction by performing an oxidation treatment after forming a physical semiconductor film. It is a figure for demonstrating the case where a layer is formed.
　図示されているように、先ず、ガラス基板１上に、還元雰囲気（Ａｒ雰囲気＋Ｈ２ガス流入）下で、スパッタリングを行い、シート抵抗値が１ｋΩ/□未満（低抵抗状態：Ｐ＋）の金属酸化物半導体膜２（サンプル膜３）を形成した。 As shown in the drawing, first, sputtering is performed on a glass substrate 1 under a reducing atmosphere (Ar atmosphere + H 2 gas inflow), and a sheet resistance value is less than 1 kΩ / □ (low resistance state: P + ). An oxide semiconductor film 2 (sample film 3) was formed.
　その後、金属酸化物半導体膜２に対して、酸化雰囲気下でのレーザーアニールを行い、金属酸化物半導体膜２の導電性やＰ型特性を低下させ、最上層である処理対象面付近では、その低下が著しく、ＥＬ素子における正孔輸送層として用いることが可能なレベルである比抵抗値（１０～１０００００Ωｃｍ）とシート抵抗値１０ｋΩ/□以上となり、正孔輸送層が形成できた。そして、中間層は、ＥＬ素子における正孔注入層として用いることが可能なレベルである比抵抗値（０．０１～１０Ωｃｍ）の中抵抗状態となり、正孔注入層が形成できた。それから、最下層は、ＥＬ素子における陽極層として用いることが可能なレベルである０．０１Ωｃｍ未満とシート抵抗値１ｋΩ/□未満となる陽極層を形成できた。 Thereafter, laser annealing is performed on the metal oxide semiconductor film 2 in an oxidizing atmosphere to reduce the conductivity and P-type characteristics of the metal oxide semiconductor film 2. The specific resistance value (10 to 100000 Ωcm) and the sheet resistance value were 10 kΩ / □ or more, which is a level that can be used as a hole transport layer in an EL device, and the hole transport layer was formed. The intermediate layer was in a medium resistance state with a specific resistance value (0.01 to 10 Ωcm), which is a level that can be used as a hole injection layer in an EL element, and a hole injection layer could be formed. Then, as the lowermost layer, an anode layer having a level of less than 0.01 Ωcm and a sheet resistance value of less than 1 kΩ / □ that can be used as an anode layer in an EL element could be formed.
　以上のようにして、陽極層、正孔注入層および正孔輸送層を一括して堆積加工できる。 As described above, the anode layer, the hole injection layer, and the hole transport layer can be collectively deposited.
　図１５は、図１４に図示したように、陽極層、正孔注入層および正孔輸送層を一括して堆積加工した場合においても、正孔輸送層は、イオン化ポテンシャルエネルギーが比較的大きいので、イオン化ポテンシャルエネルギーが大きい発光層と組み合わせられても、正孔キャリアは円滑に注入され、ＥＬ素子の発光効率を高くすることができることを示す図である。 As shown in FIG. 14, even when the anode layer, the hole injection layer, and the hole transport layer are collectively deposited as shown in FIG. 14, the hole transport layer has a relatively large ionization potential energy. It is a figure which shows that a hole carrier is smoothly inject | poured even if it combines with a light emitting layer with large ionization potential energy, and the luminous efficiency of EL element can be made high.
　図１６は、イオン化ポテンシャルエネルギーが比較的小さい従来の正孔輸送層が備えられたＥＬ素子とイオン化ポテンシャルエネルギーが比較的大きい正孔輸送層が備えられた本実施の形態のＥＬ素子との発光効率を比較した図である。 FIG. 16 shows the luminous efficiency of the EL device provided with the conventional hole transport layer having a relatively low ionization potential energy and the EL device according to the present embodiment provided with the hole transport layer having a relatively large ionization potential energy. FIG.
　図示されているようにイオン化ポテンシャルエネルギーが比較的大きい正孔輸送層が備えられた本実施の形態のＥＬ素子において、発光効率が高いことが確認された。 As shown in the drawing, it was confirmed that the EL device of this embodiment provided with a hole transport layer having a relatively large ionization potential energy has high luminous efficiency.
　図１７は、本実施の形態のＥＬ素子の概略構成を示す図である。 FIG. 17 is a diagram showing a schematic configuration of the EL element of the present embodiment.
　図示されているように、ＥＬ素子１０は、ガラス基板１上に、陽極２（または、透明電極ＩＴＯ）と、正孔（ホール）注入・輸送層３と、発光層４と、電子注入層５と、陰極６と、が順に積層された構成となっている。 As shown in the figure, the EL element 10 includes an anode 2 (or a transparent electrode ITO), a hole injection / transport layer 3, a light emitting layer 4, and an electron injection layer 5 on a glass substrate 1. And the cathode 6 are laminated in order.
　このような発光効率が高いＥＬ素子１０を備えた表示装置は、その表示品位の向上を実現できる。 Such a display device including the EL element 10 having high light emission efficiency can realize improvement in display quality.
　本発明の金属酸化物においては、Ｘ線回折分析において、ＣｕＡｌＯ２組成に基づく結晶性ピークのみを示すことが好ましい。 In the metal oxide of the present invention, it is preferable to show only a crystalline peak based on the CuAlO 2 composition in the X-ray diffraction analysis.
　本発明の金属酸化物においては、Ｘ線回折分析において、ＣｕＡｌ２Ｏ４組成に基づく結晶性ピークを示さないことが好ましい。 In the metal oxide of the present invention, it is preferable that the crystallinity peak based on the CuAl 2 O 4 composition is not shown in the X-ray diffraction analysis.
　上記酸化銅と、上記酸化アルミニウムと、を従来方法である乾式混合した混合粉末を、不活性ガス下で熱処理した後に、粉砕処理して得られた金属酸化物は、比抵抗値を上げる要因であるＣｕＡｌ２Ｏ４が含有されたＣｕＡｌＯ２が生成されやすいが、溶媒存在下で、上記酸化銅と、上記酸化アルミニウムと、を粉砕しながら湿式混合した混合粉末を、不活性ガス下で熱処理した後に、粉砕処理して得られる本発明の金属酸化物は、上記不活性ガス下での熱処理時に、ＣｕＡｌＯ２への結晶化が進みやすいので、比抵抗値を上げる要因であるＣｕＡｌ２Ｏ４が含有されたＣｕＡｌＯ２は生成され難い。 The metal oxide obtained by pulverizing the mixed powder obtained by dry-mixing the copper oxide and the aluminum oxide, which is a conventional method, after heat treatment under an inert gas is a factor that increases the specific resistance value. CuAlO 2 containing certain CuAl 2 O 4 is likely to be produced, but a mixed powder obtained by wet-mixing the copper oxide and the aluminum oxide while being pulverized in the presence of a solvent was heat-treated under an inert gas. Later, the metal oxide of the present invention obtained by pulverization is easily crystallized into CuAlO 2 during the heat treatment under the above inert gas, so that CuAl 2 O 4 which is a factor for increasing the specific resistance value is increased. The contained CuAlO 2 is hardly generated.
　よって、本発明の金属酸化物を用いて、スパッタリングや蒸着をすれば、イオン化ポテンシャルエネルギーの大きな発光層の正孔注入層や正孔輸送層として、十分に機能できる比較的イオン化ポテンシャルエネルギーが大きい金属酸化物半導体膜を形成することができる。 Therefore, if sputtering or vapor deposition is performed using the metal oxide of the present invention, a metal having a relatively large ionization potential energy that can sufficiently function as a hole injection layer or a hole transport layer of a light emitting layer having a large ionization potential energy. An oxide semiconductor film can be formed.
　本発明の金属酸化物半導体膜は、上記金属酸化物を加圧固形化した材料を、上記不活性ガスに、酸化雰囲気とする第１のガスが加えられている状態で、スパッタリングまたは、蒸着させて形成されていてもよい。 The metal oxide semiconductor film of the present invention is obtained by sputtering or evaporating a material obtained by pressurizing and solidifying the metal oxide in a state where a first gas that is an oxidizing atmosphere is added to the inert gas. It may be formed.
　スパッタリングまたは、蒸着を、上記不活性ガスに、酸化雰囲気とする第１のガスが加えられている状態で、行うことにより、イオン化ポテンシャルエネルギーが小さくなる方向に制御された金属酸化物半導体膜を形成することができる。 Sputtering or vapor deposition is performed in a state where the first gas that is an oxidizing atmosphere is added to the inert gas, thereby forming a metal oxide semiconductor film that is controlled in a direction in which the ionization potential energy is reduced. can do.
　本発明の金属酸化物半導体膜は、上記金属酸化物を加圧固形化した材料を、上記不活性ガスに、還元雰囲気とする第２のガスが加えられている状態で、スパッタリングまたは、蒸着させて形成されていてもよい。 The metal oxide semiconductor film of the present invention is obtained by sputtering or evaporating a material obtained by solidifying the above metal oxide under pressure in a state where a second gas serving as a reducing atmosphere is added to the inert gas. It may be formed.
　スパッタリングまたは、蒸着を、上記不活性ガスに、還元雰囲気とする第２のガスが加えられている状態で、行うことにより、イオン化ポテンシャルエネルギーがさらに大きくなる方向に制御された金属酸化物半導体膜を形成することができる。 A metal oxide semiconductor film whose ionization potential energy is controlled to be further increased by performing sputtering or vapor deposition in a state where a second gas serving as a reducing atmosphere is added to the inert gas. Can be formed.
　本発明の金属酸化物半導体膜においては、上記金属酸化物半導体膜に対して、酸化処理または、還元処理を行い、膜厚方向において、上記比抵抗値が異なるように形成してもよい。 In the metal oxide semiconductor film of the present invention, the metal oxide semiconductor film may be formed so as to have different specific resistance values in the film thickness direction by performing oxidation treatment or reduction treatment.
　スパッタリングまたは、蒸着させて形成された上記金属酸化物半導体膜に対して、酸化処理または、還元処理を行い、膜厚方向において、上記比抵抗値が異なるように形成できるので、膜厚方向において、上記比抵抗値が異なる金属酸化物半導体膜を比較的容易に形成することができる。 The metal oxide semiconductor film formed by sputtering or vapor deposition is subjected to oxidation treatment or reduction treatment, and can be formed so that the specific resistance value is different in the film thickness direction. Metal oxide semiconductor films having different specific resistance values can be formed relatively easily.
　本発明の金属酸化物半導体膜においては、上記金属酸化物半導体膜に対して、所定領域に酸化処理を行い、上記所定領域の比抵抗値を上げ、絶縁領域を形成してもよい。 In the metal oxide semiconductor film of the present invention, the metal oxide semiconductor film may be oxidized in a predetermined region to increase the specific resistance value of the predetermined region, thereby forming an insulating region.
　スパッタリングまたは、蒸着させて形成された上記金属酸化物半導体膜に対して、所定領域に酸化処理を行い、上記所定領域の比抵抗値を上げ、絶縁領域を形成できるので、別途の絶縁膜やフォートレジストなどを用いる場合に比べると、比較的容易に絶縁領域を形成することができる。 The metal oxide semiconductor film formed by sputtering or evaporation can be oxidized in a predetermined region to increase the specific resistance value of the predetermined region and form an insulating region. Compared to the case where a resist or the like is used, the insulating region can be formed relatively easily.
　本発明の金属酸化物半導体膜において行われる上記酸化処理は、酸素雰囲気下でのレーザーアニール処理および酸素プラズマ処理の何れかであってもよい。 The oxidation treatment performed on the metal oxide semiconductor film of the present invention may be either laser annealing treatment or oxygen plasma treatment in an oxygen atmosphere.
　上記酸素雰囲気下でのレーザーアニール処理や上記酸素プラズマ処理を用いることにより、上記金属酸化物半導体膜に、局所的に酸化処理を行うことができる。 By using the laser annealing treatment in the oxygen atmosphere or the oxygen plasma treatment, the metal oxide semiconductor film can be locally oxidized.
　本発明の膜厚方向において、上記比抵抗値が異なるように形成された金属酸化物半導体膜は、上記金属酸化物を加圧固形化した材料を、不活性ガス下で、スパッタリングまたは、蒸着させて形成された金属酸化物半導体膜と、上記金属酸化物を加圧固形化した材料を、上記不活性ガスに、酸化雰囲気とする第１のガスが加えられている状態で、スパッタリングまたは、蒸着させて形成された金属酸化物半導体膜と、上記金属酸化物を加圧固形化した材料を、上記不活性ガスに、還元雰囲気とする第２のガスが加えられている状態で、スパッタリングまたは、蒸着させて形成された金属酸化物半導体膜と、が積層されて形成されていてもよい。 In the film thickness direction of the present invention, the metal oxide semiconductor film formed so as to have different specific resistance values is obtained by sputtering or evaporating a material obtained by solidifying the metal oxide under pressure under an inert gas. Sputtering or vapor deposition of the metal oxide semiconductor film formed and the material obtained by pressurizing and solidifying the metal oxide in a state where a first gas that is an oxidizing atmosphere is added to the inert gas. In a state where a second gas serving as a reducing atmosphere is added to the inert gas, the metal oxide semiconductor film formed and the material obtained by pressurizing and solidifying the metal oxide are sputtered or A metal oxide semiconductor film formed by vapor deposition may be stacked.
　スパッタリングまたは、蒸着させて形成された上記金属酸化物半導体膜に対して、酸化処理や還元処理を行うことなく、膜厚方向において、上記比抵抗値が異なるように形成された金属酸化物半導体膜を形成することができる。 The metal oxide semiconductor film formed so that the specific resistance value differs in the film thickness direction without performing oxidation treatment or reduction treatment on the metal oxide semiconductor film formed by sputtering or evaporation. Can be formed.
　本発明のエレクトロルミネセンス素子においては、上記発光層は、イオン化ポテンシャルエネルギーが６．１ｅＶ以上であり、上記発光層と接するように、上記金属酸化物を加圧固形化した材料を、上記不活性ガスに、還元雰囲気とする第２のガスが加えられている状態で、スパッタリングまたは、蒸着させて形成された金属酸化物半導体膜が設けられていることが好ましい。 In the electroluminescent device of the present invention, the light emitting layer has an ionization potential energy of 6.1 eV or more, and the material obtained by pressurizing and solidifying the metal oxide so as to be in contact with the light emitting layer is the inert material. It is preferable that a metal oxide semiconductor film formed by sputtering or vapor deposition in a state where a second gas serving as a reducing atmosphere is added to the gas.
　本発明のエレクトロルミネセンス素子には、イオン化ポテンシャルエネルギーが６．１ｅＶ以上と比較的大きい発光層が備えられており、この発光層の正孔注入層や正孔輸送層として、十分に機能できる比較的イオン化ポテンシャルエネルギーが大きい金属酸化物半導体膜として、上記不活性ガスに、還元雰囲気とする第２のガスが加えられている状態で、スパッタリングまたは、蒸着されたイオン化ポテンシャルエネルギーがさらに大きくなる方向に制御された金属酸化物半導体膜が備えられているので、発光効率をさらに向上できる。 The electroluminescent device of the present invention is provided with a light emitting layer having a relatively large ionization potential energy of 6.1 eV or more, and can be sufficiently functioned as a hole injection layer or a hole transport layer of the light emitting layer. As a metal oxide semiconductor film having a large ionization potential energy, in a state where the ionization potential energy sputtered or deposited is further increased in a state where the second gas serving as a reducing atmosphere is added to the inert gas. Since the controlled metal oxide semiconductor film is provided, the light emission efficiency can be further improved.
　本発明のエレクトロルミネセンス素子においては、上記発光層は、イオン化ポテンシャルエネルギーが６．１ｅＶ以上であり、上記膜厚方向において、上記比抵抗値が異なるように形成された金属酸化物半導体膜中、最も上記比抵抗値が高い層は、正孔輸送層として、上記発光層と接するように形成されており、最も上記比抵抗値が低い層は、上記陽極として、形成されており、上記比抵抗値が中間の層は、上記陽極と上記正孔輸送層との間に、正孔注入層として、形成されていることが好ましい。 In the electroluminescent device of the present invention, the light emitting layer has an ionization potential energy of 6.1 eV or more, and in the metal oxide semiconductor film formed so that the specific resistance value is different in the film thickness direction, The layer with the highest specific resistance value is formed as a hole transport layer so as to be in contact with the light emitting layer, and the layer with the lowest specific resistance value is formed as the anode, and the specific resistance is The layer having an intermediate value is preferably formed as a hole injection layer between the anode and the hole transport layer.
　上記エレクトロルミネセンス素子においては、上記膜厚方向において、上記比抵抗値が異なるように形成された金属酸化物半導体膜の各々の層を、正孔輸送層、陽極および正孔注入層として用いているので、正孔輸送層、陽極および正孔注入層を比較的容易に形成することができる。 In the electroluminescence element, each layer of the metal oxide semiconductor film formed so as to have different specific resistance values in the film thickness direction is used as a hole transport layer, an anode, and a hole injection layer. Therefore, the hole transport layer, the anode, and the hole injection layer can be formed relatively easily.
　本発明は上記した各実施の形態に限定されるものではなく、請求項に示した範囲で種々の変更が可能であり、異なる実施の形態にそれぞれ開示された技術的手段を適宜組み合わせて得られる実施の形態についても本発明の技術的範囲に含まれる。 The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and the present invention can be obtained by appropriately combining technical means disclosed in different embodiments. Embodiments are also included in the technical scope of the present invention.
　本発明は、金属酸化物半導体膜を備えたエレクトロルミネセンス素子および表示装置に好適に用いることができる。 The present invention can be suitably used for an electroluminescent element and a display device provided with a metal oxide semiconductor film.
　１　　　　　　　　ガラス基板
　２　　　　　　　　陽極（透明電極）
　３　　　　　　　　正孔（ホール）注入・輸送層
　４　　　　　　　　発光層
　５　　　　　　　　電子注入層
　６　　　　　　　　陰極
　１０　　　　　　　ＥＬ素子 1 Glass substrate 2 Anode (transparent electrode)
3 Hole injection / transport layer 4 Light emitting layer 5 Electron injection layer 6 Cathode 10 EL element

Claims (14)

  1. 　Ｃｕ元素とＡｌ元素との原子比が１：１となるように秤量された酸化銅と、酸化アルミニウムと、から得られるＣｕ元素とＡｌ元素とを含む金属酸化物であって、
    　溶媒存在下で、上記酸化銅と、上記酸化アルミニウムと、を粉砕しながら湿式混合した混合粉末を、不活性ガス下または、還元雰囲気下で、９００度以上で熱処理した後に、粉砕処理して得られ、かつ、加圧固形化した状態における比抵抗値が１．０×１０６Ωｃｍ以下であることを特徴とする金属酸化物。     A metal oxide containing Cu element and Al element obtained from copper oxide and aluminum oxide, which are weighed so that the atomic ratio of Cu element to Al element is 1: 1,
    A mixed powder obtained by wet-mixing the copper oxide and the aluminum oxide in the presence of a solvent while being pulverized is heat-treated at 900 ° C. or higher in an inert gas or in a reducing atmosphere, and then pulverized. And a specific resistance value in a state of being pressed and solidified is 1.0 × 10 6 Ωcm or less.
  2. 　Ｘ線回折分析において、ＣｕＡｌＯ２組成に基づく結晶性ピークのみを示すことを特徴とする請求項１に記載の金属酸化物。 2. The metal oxide according to claim 1, which shows only a crystalline peak based on a CuAlO 2 composition in X-ray diffraction analysis.
  3. 　Ｘ線回折分析において、ＣｕＡｌ２Ｏ４組成に基づく結晶性ピークを示さないことを特徴とする請求項１に記載の金属酸化物。 The metal oxide according to claim 1, wherein the metal oxide does not show a crystallinity peak based on a CuAl 2 O 4 composition in X-ray diffraction analysis.
  4. 　請求項１から３の何れか１項に記載の金属酸化物を加圧固形化した材料を、不活性ガス下で、スパッタリングまたは、蒸着させて形成された金属酸化物半導体膜。 A metal oxide semiconductor film formed by sputtering or evaporating a material obtained by pressurizing and solidifying the metal oxide according to any one of claims 1 to 3 under an inert gas.
  5. 　上記不活性ガスには、酸化雰囲気とする第１のガスが加えられていることを特徴とする請求項４に記載の金属酸化物半導体膜。 5. The metal oxide semiconductor film according to claim 4, wherein the inert gas is added with a first gas serving as an oxidizing atmosphere.
  6. 　上記不活性ガスには、還元雰囲気とする第２のガスが加えられていることを特徴とする請求項４に記載の金属酸化物半導体膜。 5. The metal oxide semiconductor film according to claim 4, wherein a second gas serving as a reducing atmosphere is added to the inert gas.
  7. 　請求項４から６の何れか１項に記載の金属酸化物半導体膜に対して、酸化処理または、還元処理を行い、膜厚方向において、上記比抵抗値が異なるように形成されたことを特徴とする金属酸化物半導体膜。 The metal oxide semiconductor film according to any one of claims 4 to 6, wherein the metal oxide semiconductor film is formed so as to have different specific resistance values in the film thickness direction by performing oxidation treatment or reduction treatment. A metal oxide semiconductor film.
  8. 　請求項４から６の何れか１項に記載の金属酸化物半導体膜に対して、所定領域に酸化処理を行い、上記所定領域の比抵抗値を上げ、絶縁領域を形成したことを特徴とする金属酸化物半導体膜。 The metal oxide semiconductor film according to any one of claims 4 to 6, wherein an oxidation treatment is performed on a predetermined region, a specific resistance value of the predetermined region is increased, and an insulating region is formed. Metal oxide semiconductor film.
  9. 　上記酸化処理は、酸素雰囲気下でのレーザーアニール処理および酸素プラズマ処理の何れかであることを特徴とする請求項７または８に記載の金属酸化物半導体膜。 The metal oxide semiconductor film according to claim 7 or 8, wherein the oxidation treatment is one of laser annealing treatment and oxygen plasma treatment in an oxygen atmosphere.
  10. 　請求項４に記載の金属酸化物半導体膜と、
    　請求項５に記載の金属酸化物半導体膜と、
    　請求項６に記載の金属酸化物半導体膜と、が積層され、膜厚方向において、上記比抵抗値が異なるように形成された金属酸化物半導体膜。     The metal oxide semiconductor film according to claim 4,
    A metal oxide semiconductor film according to claim 5;
    A metal oxide semiconductor film according to claim 6, wherein the specific resistance value is different in the film thickness direction.
  11. 　陽極と陰極とを有し、上記陽極と上記陰極との間に発光層を備えたエレクトロルミネセンス素子であって、
    　上記発光層と接するように、上記発光層の上記陽極側には、請求項４から６の何れか１項に記載の金属酸化物半導体膜が備えられていることを特徴とするエレクトロルミネセンス素子。     An electroluminescent device having an anode and a cathode, and having a light emitting layer between the anode and the cathode,
    An electroluminescent device comprising the metal oxide semiconductor film according to claim 4 on the anode side of the light emitting layer so as to be in contact with the light emitting layer. .
  12. 　上記発光層は、イオン化ポテンシャルエネルギーが６．１ｅＶ以上であり、
    　上記発光層と接するように、請求項６に記載の金属酸化物半導体膜が設けられていることを特徴とする請求項１１に記載のエレクトロルミネセンス素子。
          The light emitting layer has an ionization potential energy of 6.1 eV or more,
    The electroluminescent element according to claim 11, wherein the metal oxide semiconductor film according to claim 6 is provided so as to be in contact with the light emitting layer.
  13. 　上記発光層は、イオン化ポテンシャルエネルギーが６．１ｅＶ以上であり、
    　請求項７または１０に記載の膜厚方向において、上記比抵抗値が異なるように形成された金属酸化物半導体膜中、
    　最も上記比抵抗値が高い層は、正孔輸送層として、上記発光層と接するように形成されており、
    　最も上記比抵抗値が低い層は、上記陽極として、形成されており、
    　上記比抵抗値が中間の層は、上記陽極と上記正孔輸送層との間に、正孔注入層として、形成されていることを特徴とする請求項１１に記載のエレクトロルミネセンス素子。     The light emitting layer has an ionization potential energy of 6.1 eV or more,
    In the film thickness direction according to claim 7 or 10, in the metal oxide semiconductor film formed so that the specific resistance value is different,
    The layer having the highest specific resistance value is formed so as to be in contact with the light emitting layer as a hole transport layer,
    The layer with the lowest specific resistance value is formed as the anode,
    The electroluminescent device according to claim 11, wherein the layer having an intermediate specific resistance value is formed as a hole injection layer between the anode and the hole transport layer.
  14. 　請求項１１から１３の何れか１項に記載のエレクトロルミネセンス素子を備えたことを特徴とする表示装置。 A display device comprising the electroluminescent element according to any one of claims 11 to 13.
PCT/JP2013/067118 2012-06-28 2013-06-21 Metal oxide, metal oxide semiconductor film, electroluminescent element, and display device WO2014002904A1 (en)

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