JP2007258468A - Visible-light transmitting semiconductor element, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a visible-light transmitting element wherein various visible-light transmitting semiconductor films can be formed on a transparent substrate having a low heat resistance, by forming the semiconductor films while irradiating on the films present in their depositing courses the light emitted from a light emitting device, when forming the visible-light transmitting semiconductor films. <P>SOLUTION: The visible-light transmitting semiconductor element comprises a transparent substrate 8, and a semiconductor film formed while irradiating on it a light emitted from a light emitting device 9b during depositing on the transparent substrate 8 the material containing the composition of a semiconductor. The semiconductor film comprises the semiconductor having a band gap not lower than 2.5 eV. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a visible light transmitting semiconductor element in which a semiconductor film is formed on a transparent substrate and a method for manufacturing the same.

  Conventionally, transparent semiconductor films have been used as, for example, transparent electrodes, antistatic films, heat ray reflective films, surface heating elements, and the like. In particular, an oxide semiconductor film typified by indium oxide (ITO) doped with tin is important as a material for various electronic components. However, indium contained in ITO has a low crust content and may be depleted. Therefore, in recent years, a transparent semiconductor film such as ZnO has attracted attention.

  In addition, copper delafossite has transparent and p-type semiconductor characteristics, so an n-type transparent semiconductor and a p-type transparent semiconductor are combined to form a pn junction to create a transparent diode or transparent electronic circuit. Can be expected to create. Moreover, a p-i-n structure (i is an insulating layer) can be created to produce a visible light transmitting ultraviolet light conversion solar cell or a visible light transmitting tunnel diode.

  These oxide semiconductor thin films are generally formed by PVD (physical vapor deposition) such as vacuum deposition, sputtering, ion plating, electron beam deposition, laser deposition, and CVD. It is formed on the substrate by vapor deposition such as (chemical vapor deposition) or spraying.

  However, in these methods, since it is necessary to heat the substrate to 400 ° C. or higher during vapor deposition, the substrate material must be stable even at a temperature of 400 ° C. or higher. There is a drawback that a plastic substrate having a temperature lower than 400 ° C. cannot be used.

In Japanese Patent Laid-Open No. 2000-31463, ITO is deposited on a substrate in an amorphous state as a transparent electrode material, and has a wavelength shorter than the absorption edge wavelength of the material, and has a wavelength of 30 to 100 mJ / cm ² · pulse. A method of forming a transparent electrode by irradiating a pulsed laser beam having an energy density of crystallization to form a transparent electrode is disclosed.

  Japanese Patent Application Laid-Open No. 2000-285752 discloses a step of forming an oxide layer on an organic substrate, for example, PMMA, as a photo-denaturation preventing layer for preventing photo-denaturation of the organic substrate, and on the photo-denaturation preventing layer. And forming ITO as a transparent electrode material layer, and irradiating the transparent electrode material layer with light having a wavelength shorter than the fundamental absorption edge wavelength to crystallize the transparent electrode material, A method of forming a transparent electrode is disclosed.

  In these methods, since it is not necessary to heat the substrate during film deposition, a high-quality transparent electrode can be formed even on a substrate having low heat resistance, but a step of irradiating a laser after film formation must be provided. As compared with the case where the film is formed by heating the substrate, the throughput may be reduced. In addition, since the formed film is crystallized by irradiating with a laser, there is a drawback in the manufacturing process such that a relatively large amount of light energy that penetrates into the film is required.

Japanese Patent Application Laid-Open No. 11-229120 discloses a method for forming a transparent conductive thin film in which ITO is deposited on an unheated glass substrate while irradiating an ultraviolet laser to form a transparent conductive thin film. Yes. By depositing an oxide semiconductor while irradiating an unheated substrate with an ultraviolet laser, an oxide semiconductor film excellent in transparent conductivity can be efficiently formed on the substrate. Therefore, even substrates with poor heat resistance, such as plastic substrates that could not be used with conventional evaporation methods, have excellent electrical resistance of 3 × 10 ⁻⁴ Ω · cm or less and a visible light transmittance of 90% or more. An oxide semiconductor film having conductivity can be formed.

  However, each of the above methods discloses an improved manufacturing method for using a transparent oxide conductor as a conductive film or an electrode, and refers to the manufacture of a semiconductor element utilizing the function as a semiconductor. It has not been.

Japanese Patent Application Laid-Open No. 2004-311845 describes a visible light transmission structure having a blue to ultraviolet light power generation function, which is composed of a p-type semiconductor and a pn junction layer of an n-type semiconductor on a transparent substrate. In this visible light transmission structure equipped with blue to ultraviolet light power generation function, CuAlO ₂ is used for p-type semiconductor and ZnO thin film is used for pn junction layer of n-type semiconductor. It was necessary to form a pn junction by heating the film to 400 ° C. or higher, and there was a drawback that a plastic substrate having a deformation temperature lower than 400 ° C. cannot be used as described above.
That is, no attempt has been made so far to form a visible light transmissive semiconductor element while performing light irradiation.

JP 2000-31463 A JP 2000-285752 JP Japanese Patent Laid-Open No. 11-229120 JP 2004-311845 A

  In order to form a semiconductor material, it is usually necessary to heat to several hundred degrees C. or more, and thus a material having poor heat resistance such as plastic cannot be used as a substrate for forming a semiconductor material. Substrates such as plastics are cheaper than oxide substrates such as sapphire, quartz, and glass in terms of cost, and are lighter. Therefore, it is industrially necessary to form thin films with semiconductor functions on plastics. Useful. Thus, there is a need for a novel method for forming a visible light transmissive semiconductor element that can be applied to substrates such as plastics that could not be used due to problems such as deformation and softening.

  The object of the present invention is to form various semiconductor films with heat resistance by forming a semiconductor film while irradiating light from a light emitting device to the film being deposited. Another object of the present invention is to provide a visible light transmissive semiconductor element that can be formed on a transparent substrate having a low thickness.

The invention according to claim 1 is characterized by comprising a transparent substrate and a semiconductor film formed while irradiating light from a light emitting device during deposition of a material containing the composition of the semiconductor on the transparent substrate. The visible light transmitting semiconductor element.
The invention according to claim 2 is a transparent substrate, a semiconductor film formed while irradiating light from a light emitting device during deposition of a material containing the composition of an n-type semiconductor on the transparent substrate, and the semiconductor film A visible light transmitting semiconductor element comprising: a semiconductor film formed while irradiating light from a light emitting device during deposition of a material containing a composition of a p-type semiconductor.
The invention according to claim 3 is a transparent substrate, a semiconductor film formed while irradiating light from a light emitting device during deposition of a material containing a composition of a p-type semiconductor on the transparent substrate, and the semiconductor film And a semiconductor film formed while irradiating light from a light emitting device during deposition of a material containing an n-type semiconductor composition.
The invention according to claim 4 is characterized in that the wavelength of the light emitted from the light emitting device is shorter than the fundamental absorption edge of the semiconductor film. The visible light transmitting semiconductor element according to one claim.
The invention according to claim 5 is the visible light transmission semiconductor element according to any one of claims 1 to 4, wherein the semiconductor film is made of a semiconductor having a band gap of 2.5 eV or more. It is.
The invention according to claim 6, wherein the semiconductor film is ZnO, SnO ₂ , In ₂ O ₃ , CdIn ₂ O ₄ , MgIn ₂ O ₄ , ZnGa ₂ O ₄ , InGaZnO ₄ , GaN, copper aluminum oxide, copper The main component is a material selected from gallium oxide, copper indium oxide, copper chromium oxide, copper scandium oxide, copper yttrium oxide, silver indium oxide, strontium copper oxide, and gallium nitride. The visible light transmitting semiconductor element according to any one of claims 1 to 5.
The invention according to claim 7 is that the semiconductor film is added with one or more materials of Mg, Ca, Sr, Sb, B, Al, Ga, In, N, Ni, Sn, or Cr. 7. The visible light transmitting semiconductor element according to claim 6, wherein:
The invention according to claim 8 is characterized in that a visible light transmitting electrode layer is formed between the transparent substrate and the semiconductor film formed on the transparent substrate. 6. The visible light transmitting semiconductor element according to any one of claims 6.
The invention according to claim 9, wherein the visible light transmitting electrode layer is made of ZnO, SnO ₂ , In ₂ O ₃ , CdIn ₂ O ₄ , MgIn ₂ O ₄ , ZnGa ₂ O ₄ , InGaZnO ₄ , GaN, copper aluminum oxide The main component is a material selected from copper, gallium oxide, copper indium oxide, copper chromium oxide, copper scandium oxide, copper yttrium oxide, silver indium oxide, and strontium copper oxide. 9. The visible light transmissive semiconductor element according to claim 8.
The invention according to claim 10, wherein the visible light transmitting electrode layer is added with one or more materials of Mg, Ca, Sr, Sb, B, Al, Ga, In, N, Ni, Sn, or Cr. 10. The visible light transmitting semiconductor element according to claim 9, wherein the visible light transmitting semiconductor element is provided.
The invention according to claim 11 is characterized in that a visible light transmitting intrinsic semiconductor layer or a visible light transmitting insulating layer is formed between the p-type semiconductor film and the n-type semiconductor film. Alternatively, the visible light transmitting semiconductor element according to claim 3.
The invention according to claim 12, wherein the visible light transmitting intrinsic semiconductor is a material selected from ZnO, SnO ₂ , In ₂ O ₃ , CdIn ₂ O ₄ , MgIn ₂ O ₄ , ZnGa ₂ O ₄ , InGaZnO ₄ and GaN. 12. The visible light transmissive semiconductor element according to claim 11, characterized in comprising as a main component.
The invention according to claim 13, wherein the visible light transmittance insulating _{layer, SiO 2, SnO 2, B} 2 O 3, P 2 O 5, ZnO, Y 2 O 3, ZrO 2, HfO 2, CeO, MgO 13. The visible light transmitting semiconductor element according to claim 11, wherein the visible light transmissive semiconductor element comprises a material selected from Bi ₂ O ₃ and TiO ₂ as a main component.
The invention according to claim 14 is characterized in that the temperature of the transparent substrate is controlled when light is irradiated from the light emitting device. It is a manufacturing method of the visible light transmissive semiconductor element of description.

  According to the present invention, a laminated structure composed of an n-type semiconductor film, a p-type semiconductor film, an intrinsic semiconductor film, an insulator film, a transparent electrode, and the like can be produced without heating using light irradiation. It can also be applied to transparent substrates with low heat resistance. In addition, according to the present invention, without using a relatively expensive substrate material such as quartz glass or borosilicate glass having high heat resistance, inexpensive lead glass or soda lime glass having inferior heat resistance than these glasses, Furthermore, a material such as plastic having extremely poor heat resistance can be used as a transparent substrate for forming a semiconductor element. Furthermore, according to the present invention, a transparent substrate such as plastic that is cheaper and lighter than a substrate such as glass can be used, which is extremely useful in the industry.

  As a result of repeated research on a method for forming a transparent conductive thin film by a vapor deposition method, the inventors of the present invention have a wavelength shorter than the absorption edge of a semiconductor film to be formed when an oxide semiconductor is grown on the transparent substrate by a vapor deposition method. It has been found that when light is deposited on a film being deposited, it acts as photoexcitation on the outermost surface layer during the thin film growth process, and the properties of the visible light transmitting semiconductor film can be controlled.

  In general, copper delafossite thin film, which is representative of visible light transmitting p-type semiconductors, has a high electrical resistance in an amorphous state and does not exhibit p-type semiconductor characteristics when deposited at room temperature, but it does not exhibit p-type semiconductor characteristics, but heating and deposition during deposition It is known that subsequent annealing promotes crystallization and improves conductivity and visible light transmittance. On the other hand, with regard to ZnO, which is a typical n-type transparent oxide semiconductor, ZnO deposited at room temperature is polycrystalline and has excellent electrical conductivity. However, it is difficult to form a good pn junction in combination with a p-type semiconductor film. In ZnO, crystallization is promoted by heating the substrate during film formation, baking after film formation, or annealing, thereby improving the interface characteristics as a semiconductor, which is advantageous for forming a semiconductor pn junction. Therefore, in order to form a high-quality pn junction, it is effective to inject thermal energy, light energy, plasma energy or the like into the film to promote crystallization. The present inventors have found that ZnO deposited at room temperature has a high electrical conductivity, and found that ZnO can be used not only as an n-type semiconductor film but also as a ZnO thin film as an electrode, and based on these findings The present invention has been completed.

  That is, an object of the present invention is to provide a visible light transmitting semiconductor element in which a high-performance semiconductor film and thus a semiconductor element are formed on various transparent substrates by using light irradiation to a semiconductor thin film being deposited. According to the present invention, as a thin film deposited on a substrate by light irradiation without irradiating the film being irradiated with light, for example, a thin film having high conductivity as an electrode, a semiconductor characteristic It is possible to form a thin film having various characteristics such as an intrinsic semiconductor film or an insulating film having a relatively high resistivity from the same material. A visible light transmitting semiconductor element can be manufactured by forming each functional film thus formed into a multilayer structure.

  Furthermore, in the present invention, by setting the wavelength of the irradiated light to a wavelength shorter than the absorption edge wavelength of the semiconductor film being deposited, the semiconductor film having excellent characteristics can be efficiently injected with the light energy. Can be formed. Here, the absorption edge wavelength means a wavelength of light having energy sufficient to excite electrons located at the top of the valence band of the semiconductor material to the bottom of the conduction band. Since light having a wavelength shorter than the absorption edge wavelength has energy larger than the band gap of the semiconductor material, electrons located in the valence band are excited by the conduction band and absorbed. The electrons excited in the conduction band eventually fall into the valence band, but the crystallization of the semiconductor material proceeds by the energy released at this time. Conversely, light having a wavelength longer than the absorption edge wavelength is not absorbed because electrons located in the valence band cannot be excited to the conduction band. For this reason, light having a wavelength longer than the absorption edge wavelength is transmitted through the semiconductor material and cannot contribute to crystallization of the semiconductor material.

  Since the absorption edge wavelength of a semiconductor material that transmits light up to blue is in the vicinity of 400 nm, light shorter than the absorption edge wavelength is generally ultraviolet light. In addition, when a semiconductor material having an absorption edge wavelength near 500 nm is targeted, it is also effective to irradiate visible light having a wavelength of 450 nm. The present invention includes a case where light having an absorption edge wavelength is irradiated. Further, when the amorphous absorption edge wavelength is different from the absorption edge wavelength of the crystal, it includes a case where crystallization is sufficiently advanced by irradiating light having a wavelength shorter than the absorption edge wavelengths of both phases. The absorption edge wavelength can be determined from the light transmission spectrum of the film. Light having a wavelength shorter than the absorption edge wavelength may be emitted as continuous light or as pulsed light.

For example, laser light or synchrotron radiation is used as a light source that is shorter than the absorption edge wavelength. A mercury lamp or the like also emits ultraviolet light, but a strong light source such as laser light or synchrotron radiation is preferable in order to advance crystallization at a realistic speed. Examples of lasers that emit ultraviolet light include excimer lasers and fourth harmonics of Nd-YAG lasers. Light having a wavelength shorter than the absorption edge wavelength must have sufficient intensity. For this reason, a pulse laser or a synchrotron is suitable as the light source. When a pulse laser is used, it is appropriate that the irradiation energy density is 30 to 100 mJ / cm ² · pulse. If it is less than 30 mJ / cm ² · pulse, crystallization does not proceed in the case of amorphous ITO. At 100 mJ / cm ² · pulse or more, the energy is too strong and the film often evaporates. At present, light having an energy density in this range is obtained by excimer lasers such as ArF, KrF, and XeCl, and YAG lasers.

A semiconductor having a band gap of 2.5 eV or more is used for the visible light transmitting semiconductor element of the present invention. Since the band gap energy of 2.5 eV corresponds to an optical wavelength of 500 nm, a semiconductor having a band gap energy of 2.5 eV can transmit visible light. Specific semiconductor _{materials, ZnO, SnO 2, In 2} O 3, CdIn 2 O 4, MgIn 2 O 4, ZnGa 2 O 4, InGaZnO 4, GaN, copper aluminum oxide, copper gallium oxide, copper indium Oxides, copper chromium oxides, copper scandium oxides, copper yttrium oxides, silver indium oxides or strontium copper oxides are suitable. A material containing Mg, Ca, Sr, Sb, B, Al, Ga, In, N, Ni, Sn, or Cr as an additive to these semiconductor materials is highly useful because it can adjust electrical conductivity and optical transmittance.

The visible light transmitting semiconductor element of the present invention can be easily taken out of the visible light transmitting semiconductor element by providing a visible light transmitting electrode layer between the transparent substrate and the semiconductor film formed on the transparent substrate. And the electric field applied to the formed electronic element can be made uniform. The visible light transmission electrode _{layer, ZnO, SnO 2, In 2} O 3, CdIn 2 O 4, MgIn 2 O 4, ZnGa 2 O 4, InGaZnO 4, GaN, copper aluminum oxide, copper gallium oxide, copper indium oxide Copper chromium oxide, copper scandium oxide, copper yttrium oxide, silver indium oxide, strontium copper oxide or gallium nitride as the main component, Mg, Ca, Sr, Sb, B, Al, Ga, In, It is formed from a material containing N, Ni, Sn or Cr as an additive.

  In the present invention, the material containing the semiconductor composition forming the visible light transmissive electrode layer and the material containing the semiconductor composition forming the n-type semiconductor film may be formed of the same material. By using the same material, the manufacturing process can be reduced and the required material can be reduced, which can contribute to cost reduction and improvement of throughput. For example, when ZnO is used as a material, a ZnO thin film as an electrode layer is formed at room temperature while controlling the gas atmosphere in the vacuum vessel, and then irradiated with vapor deposition to form a ZnO thin film as an n-type semiconductor. Realized by forming. Further, in the conventional manufacturing method, the lower electrode cannot avoid undesired heating in the annealing process, and in the zinc oxide target that forms the n-type semiconductor film, the resistivity is remarkably increased in the annealing process. Undesirable as a layer. Therefore, in the conventional manufacturing method, the lower electrode layer needs to use a transparent conductive film that can suppress a decrease in electrical conductivity even when heat is applied, for example, indium oxide doped with tin, or zinc oxide doped with aluminum or gallium. was there.

  Furthermore, in the method for manufacturing a visible light transmissive semiconductor element of the present invention, the temperature of the transparent substrate is controlled when light is emitted from the light emitting device. That is, when irradiating light, the transparent substrate is controlled to an appropriate temperature. When heat is generated by light irradiation and the temperature rises to such an extent that the transparent substrate is altered, for example, the temperature rise of the transparent substrate is controlled by a method of flowing cooling water through the substrate holder. Conversely, the transparent substrate may be heated within a temperature range in which the transparent substrate does not deteriorate in order to assist the progress of crystallization.

The transparent substrate used in the present invention is not particularly limited as long as it is transparent. Conventionally, a substrate conventionally used for forming an oxide semiconductor film by vapor deposition, such as Pyrex (registered trademark) glass or quartz glass, is used. Glass substrates, or oxide substrates such as sapphire, lanthanum aluminate and strontium titanate, as well as plastic substrates that could not be used because the substrate temperature had to be increased by conventional deposition methods. A substrate having poor heat resistance can also be used.
The transparent substrate is fixed to the sample holder, and the sample holder is configured to be rotated by a motor drive. Thereby, the uniformity of the produced thin film is achieved.

  Moreover, the oxide semiconductor used for this invention can be arbitrarily selected from what was used when forming a transparent semiconductor film on a transparent substrate by a vapor deposition method until now, and there is no restriction | limiting in particular.

  As such an n-type oxide semiconductor, for example, indium oxide, tin oxide, zinc oxide, gallium oxide, or a composite oxide system thereof, a magnesium indium oxide system, or the like can be given. These semiconductor films may be doped with other elements to obtain desired properties, such as high conductivity or low efficiency, for example, conductivity by doping aluminum or gallium to zinc oxide. Can be increased.

  Examples of p-type oxide semiconductors include copper aluminum oxide, copper gallium oxide, copper indium oxide, copper chromium oxide, copper scandium oxide, copper yttrium oxide, silver indium oxide, and strontium copper oxide. Is mentioned. In order to obtain these desired characteristics in the semiconductor film, for example, high conductivity or resistivity, etc., other elements may be doped, for example, conductivity by doping magnesium into copper chrome oxide. Can be increased.

  Next, there is no particular limitation on the type of vapor deposition method used for producing the visible light transmissive semiconductor element of the present invention, and vacuum vapor deposition method, sputtering method, ion plating method, high frequency ion plating method, electron beam vapor deposition method. Any method conventionally used for forming a transparent conductive thin film, such as chemical vapor deposition (CVD), may be used.

  As a vapor deposition method used in the present invention, a pulse laser vapor deposition method will be described as an example. The pulsed laser deposition method is a method for manufacturing a thin film in which deposition is performed by irradiating a target containing a desired composition of the thin film with a pulse laser to evaporate the target. A pulse laser is output from the pulse laser device, and the target in the vacuum vessel is irradiated through the optical system and the light introduction window to evaporate the target, thereby depositing a thin film on the transparent substrate. A plurality of targets are provided in the vacuum vessel, and the target irradiated by driving the motor can be exchanged without breaking the vacuum. Furthermore, the target can be rotated by a motor drive, and the target is not cratered by scanning the target rather than irradiating the place where the target is fixed.

  In the present invention, it is necessary to perform a vapor deposition process while irradiating light to a transparent substrate, that is, to deposit a semiconductor film while irradiating light to a growing semiconductor film. As light to be irradiated at this time, for example, excimer laser light such as ArF, KrF, XeF, or XeCl, harmonics of YAG laser light, synchrotron radiation light, or the like can be used. The wavelength of the laser light is shorter than the absorption edge wavelength of the thin film to be formed, and may be any wavelength that can excite the material constituting the thin film. For example, a wavelength of 350 nm or less is desirable.

As the light used for the thin film irradiation of the present invention, a Nd-YAG fourth harmonic laser was used. The laser output from the laser device is configured to irradiate the transparent substrate in the vacuum vessel through the optical system and the introduction window. The average energy density of a laser depends on various physical properties such as a crystallization temperature of an oxide semiconductor that is a target material. For example, a copper delafossite oxide system was used as the oxide semiconductor, and in order to optimize its semiconductor characteristics and visible light transmittance, annealing was performed at 500 ° C. by laser irradiation of 30 mJ / cm ² or more. Equivalent effect is obtained. This ultraviolet laser is usually used by adjusting the output of a laser oscillator and the output light by an optical system such as an attenuator or a lens.

  In producing the visible light transmitting semiconductor element of the present invention, it is not necessary to heat the transparent substrate during the vapor deposition treatment as in the conventional method, and it can be performed at an ambient temperature, for example, room temperature. Moreover, it can also aim at the synergistic effect of light irradiation and a heating and heating to such an extent that a transparent substrate does not deform | transform. Furthermore, in order to suppress the influence which a transparent substrate receives from light irradiation, a transparent substrate may be cooled etc. and you may make it a constant temperature state.

  As described above, in the production of the visible light transmitting semiconductor element of the present invention, only the transparent substrate is not heated and only the light irradiation is different from the conventional one, and all other deposition conditions are the same as the conventional one. They are the same and do not need to be changed. In this way, visible light transmissive semiconductor elements such as pn junctions and p-i-n junctions that could not be obtained unless the substrate temperature is heated to 400 ° C. or higher can be formed at room temperature.

FIG. 1 is a view showing an example of a vapor deposition apparatus used for producing a visible light transmitting semiconductor element of the present invention. As shown in the figure, the vacuum vessel 1 holds an oxygen gas introduction tube (stainless steel tube) 3 for introducing oxygen, a mass flow controller 13 for controlling the flow rate of oxygen, and the vacuum vessel 1 inside a vacuum. An exhaust valve 2 connected to a vacuum pump 11 is connected. In the vacuum vessel 1, Al-doped ZnO target 5a, ZnO target 5b, and CuCrO ₂ target 5c are installed as materials. Further, an optical system 7a for adjusting the laser output of the ultraviolet laser beam 6a irradiated to the target 5 from the first laser oscillation device 9a and a light introduction window 4a for introducing the ultraviolet laser beam 6a into the vacuum vessel 1 Is provided. Further, an optical system 7b for adjusting the laser output of the ultraviolet laser beam 6b irradiated to the substrate 8 from the second laser oscillation device 9b and a light introduction window 4b for introducing the ultraviolet laser beam 6b into the vacuum vessel 1 are provided. Is provided. The targets 5a to 5c are ablated by the laser beam 6a and deposited on the transparent substrate 8.

Below, the outline | summary of operation | movement of this vapor deposition apparatus is demonstrated. First, after mounting the transparent substrate 8 in the vacuum vessel 1, the exhaust valve 2 is opened, and after evacuating the vacuum inside the vessel to about 10 ⁻⁵ to 10 ⁻⁷ Pa by the vacuum pump 11, oxygen gas is introduced Oxygen gas is introduced from the tube 3 so that the oxygen atmospheric pressure is about 10 ² to 10 ⁻² Pa. Next, while irradiating the transparent substrate 8 supported by the sample holder 10 with the ultraviolet laser beam 6b from the second laser oscillation device 9b through the optical system 7b and the light introduction window 4b, the ultraviolet laser beam from the first laser oscillation device 9a is irradiated. The target 5 is irradiated with the optical laser beam 6a through the optical system 7a and the light introduction window 4a to evaporate the target 5, and the oxide semiconductor is deposited on the transparent substrate 8. At this time, the transparent substrate 8 may not be heated, but may be heated to an extent that does not affect the transparent substrate 8 if desired. When a plastic substrate is used as the transparent substrate 8, the substrate temperature is preferably 100 ° C. or lower. There is no restriction | limiting in particular in vapor deposition time, What is necessary is just to select suitably according to the desired film thickness of the transparent semiconductor thin film formed. In this way, a transparent visible light transmitting semiconductor element having semiconductor characteristics and transparent is formed. The thickness of this oxide semiconductor film varies depending on the application, but is usually about 0.01 to 10 μm.

Example 1
In Example 1, formation of an n-type transparent oxide semiconductor thin film will be described. According to experience so far, ZnO deposited at room temperature is polycrystalline and has excellent electrical conductivity, but it contains many oxygen defects, so it has high electrical conductivity but is a p-type semiconductor. It is difficult to form a pn junction that may be combined with a film, resulting in an ohmic junction. However, crystallization is promoted by heating the substrate during the ZnO film formation, or performing baking or annealing after the film formation, so that the interface characteristics as an intrinsic semiconductor can be improved and a semiconductor pn junction can be formed. Therefore, in order to form a high-quality pn junction, crystallization is promoted by injecting thermal energy, light energy, plasma energy or the like into the film. For example, a ZnO thin film can increase resistance as the substrate heating temperature increases during film formation.

Next, a method for forming a zinc oxide (ZnO) thin film on the quartz glass substrate 8 using the vapor deposition apparatus shown in FIG. 1 will be described. First, the quartz glass substrate 8 is placed in a predetermined position in the vacuum vessel 1, the exhaust valve 2 is opened, and the vacuum pump 11 is exhausted until the degree of vacuum in the vacuum vessel 1 becomes about 5 × 10 ⁻⁶ Pa. After that, oxygen gas was introduced from the oxygen gas introduction pipe 3 so that the oxygen atmosphere pressure was 1.33 Pa. A 4th harmonic (266 nm) pulsed laser beam emitted from the first Nd-YAG laser oscillation device 9a is irradiated onto the zinc oxide (ZnO) target 5b through the optical system 7a and the light introduction window 4a, and the quartz glass substrate 8 is irradiated. A zinc oxide (ZnO) film is vapor-deposited, and simultaneously with this vapor deposition, a 4th harmonic (266 nm) pulsed laser beam emitted from the second Nd-YAG laser oscillation device 9b is applied to the quartz glass substrate 8 being deposited in the optical system 7b. And irradiation through the light introduction window 4b.

The temperature of the quartz glass substrate 8 was room temperature. Also, the energy density of the ablation laser is about 25W / cm ^2, substrate energy density of the irradiated laser is approximately 0.3-0.6W / cm ^2, the thickness of the zinc oxide (ZnO) thin film was about 150 nm. FIG. 2 shows the results of measuring the resistance of the obtained zinc oxide (ZnO) thin film by the four-end needle method. As shown in the figure, when the energy density of the substrate irradiation laser is small, the change is small, but the resistance of the zinc oxide (ZnO) film increases as the energy density increases.

Comparative Example 1
Next, a method for forming a zinc oxide (ZnO) thin film on the quartz glass substrate 8 without performing light irradiation with a substrate irradiation laser using the vapor deposition apparatus shown in FIG. 1 will be described. First, the quartz glass substrate 8 is placed in a predetermined position in the vacuum container 1, the exhaust valve 2 is opened, and the vacuum pump 11 is evacuated until the degree of vacuum in the container becomes about 5 × 10 ⁻⁶ Pa. The oxygen gas was introduced from the oxygen gas introduction pipe 3 so that the oxygen atmosphere pressure was 1.33 Pa. Oxidized on transparent substrate 8 by irradiating zinc oxide (ZnO) target 5b with 4th harmonic (266nm) pulsed laser light emitted from first Nd-YAG laser oscillator 9a through optical system 7a and light introduction window 4a A zinc (ZnO) thin film was deposited.

The temperature of the quartz glass substrate 8 was room temperature, the energy density of the ablation laser was about 25 W / cm ² , and the thickness of the zinc oxide (ZnO) thin film was about 150 nm. Example 1 was the same as Example 1 except that no light irradiation with a substrate irradiation laser was performed during deposition. FIG. 2 shows the measurement results obtained by measuring the resistance of the obtained zinc oxide (ZnO) thin film by the four-end needle method.

Comparative Example 2
Next, a method for forming a zinc oxide (ZnO) thin film on a quartz glass substrate by performing post-thermal annealing after film formation without using the substrate irradiation laser for light irradiation using the vapor deposition apparatus shown in FIG. 1 will be described. To do. First, the quartz glass substrate 8 is placed in a predetermined position in the vacuum container 1, the exhaust valve 2 is opened, and the vacuum pump 11 is evacuated until the degree of vacuum in the container becomes about 5 × 10 ⁻⁶ Pa. After the quartz glass substrate 8 was heated to 500 ° C., oxygen gas was introduced from the oxygen gas introduction tube 3 so that the oxygen atmosphere pressure was 1.33 Pa. A 4th harmonic (266 nm) pulsed laser beam emitted from the first Nd-YAG laser oscillation device 9a is irradiated onto the zinc oxide (ZnO) target 5b through the optical system 7a and the light introduction window 4a, and the quartz glass substrate 8 is irradiated. A non-doped zinc oxide film was deposited at room temperature. Thereafter, the quartz glass substrate 8 was heated to 500 ° C. and post-thermal annealing was performed for 10 minutes.

The energy density of the ablation laser was about 25 W / cm ² and the thickness of the zinc oxide (ZnO) thin film was about 150 nm. The same as Comparative Example 2 except that post-thermal annealing was performed after film formation. FIG. 2 shows the results of measuring the resistance of the obtained zinc oxide (ZnO) thin film by the four-end needle method.

As shown in Figure 2, zinc oxide (ZnO) thin film has many oxygen vacancies and low resistance when deposited at room temperature. However, when it is formed by irradiating light as in Example 1, the resistance can be increased significantly. An intrinsic semiconductor zinc oxide (ZnO) film can be obtained without heating the substrate. Further, as shown in FIG. 2, by controlling the laser irradiation energy, the characteristics of the zinc oxide (ZnO) thin film can be widely controlled without heating the transparent substrate. For example, with 0.6 W / cm ² laser irradiation, characteristics equivalent to those of the zinc oxide (ZnO) film of Comparative Example 2 prepared by heating the transparent substrate to 500 ° C. can be obtained without heating.

Example 2
In Example 1, the formation of an n-type transparent oxide semiconductor thin film has been described. In Example 2, the formation of a p-type transparent semiconductor thin film will be described. In general, copper delafossite thin film, such as copper chromium oxide (CuCrO ₂ ), which is representative of visible light transmitting p-type semiconductors, has a high electrical resistance in an amorphous state and does not exhibit p-type semiconductor characteristics when deposited at room temperature. However, it is known that crystallization is promoted by heating the substrate during film formation or annealing after film formation, and the conductivity and visible light transmittance are improved. Therefore, the resistance of the copper delafossite thin film tends to decrease as the substrate heating temperature increases during film formation.

Next, a method for forming a CuCrO ₂ thin film on the quartz glass substrate 8 using the vapor deposition apparatus shown in FIG. 1 will be described. First, the quartz glass substrate 8 is placed in a predetermined position in the vacuum vessel 1, the exhaust valve 2 is opened, and the vacuum pump 11 is exhausted until the degree of vacuum in the vacuum vessel 1 becomes about 5 × 10 ⁻⁶ Pa. After that, oxygen gas was introduced from the oxygen gas introduction pipe 3 so that the oxygen atmosphere pressure was 0.266 Pa. Quartz glass is irradiated with magnesium-doped copper chromium oxide (CuCrO ₂ ) by irradiating the 4th harmonic (266 nm) pulsed laser light emitted from the first Nd-YAG laser oscillator 9a through the optical system 7 and the light introduction window 4a. A CuCrO ₂ film is vapor-deposited on the substrate 8, and simultaneously with this vapor deposition, a 4th harmonic (266 nm) pulse laser beam emitted from the second Nd-YAG laser oscillation device 9b is applied to the quartz glass substrate 8 during the deposition. Illuminated through 7b and light introduction window 4b.

The temperature of the quartz glass substrate 8 was room temperature. The energy density of the ablation laser is about 25 W / cm ² , and the energy density of the pulsed laser light applied to the CuCrO ₂ thin film being deposited on the quartz glass substrate 8 is about 0.3-0.6 W / cm ² , the CuCrO ₂ thin film The film thickness was about 150 nm. FIG. 3 shows the results of measuring the resistance of the obtained CuCrO ₂ thin film by the four-end needle method. As shown in the figure, when the energy density of the pulse laser beam is small, the change is small, but the resistance of the CuCrO ₂ film decreases as the energy density increases.

Comparative Example 3
A method of forming a CuCrO ₂ film on the quartz glass substrate 8 without performing light irradiation by the substrate irradiation laser using the vapor deposition apparatus shown in FIG. First, the quartz glass substrate 8 is placed in a predetermined position in the vacuum container 1, the exhaust valve 2 is opened, and the vacuum pump 11 is evacuated until the degree of vacuum in the container becomes about 5 × 10 ⁻⁶ Pa. The oxygen gas was introduced from the oxygen gas introduction pipe 3 so that the oxygen atmosphere pressure was 1.33 Pa. Irradiate a magnesium-doped copper chromium oxide (CuCrO ₂ ) target 5c with a 4th harmonic (266 nm) pulse laser beam emitted from the first Nd-YAG laser oscillation device 9a through the optical system 7a and the light introduction window 4a. A CuCrO ₂ thin film was deposited on the quartz glass substrate 8.

The temperature of the quartz glass substrate 8 was room temperature, the energy density of the ablation laser was about 25 W / cm ² , and the thickness of the CuCrO ₂ thin film was about 150 nm. Example 2 was the same as Example 2 except that no light irradiation with a substrate irradiation laser was performed during deposition. FIG. 3 shows the results of measuring the resistance of the obtained zinc oxide thin film by the four-end needle method.

Comparative Example 4
A method of forming a CuCrO ₂ film on the quartz glass substrate 8 by heating the quartz glass substrate 8 during deposition using the vapor deposition apparatus shown in FIG. First, the quartz glass substrate 8 is placed in a predetermined position in the vacuum vessel 1, the exhaust valve 2 is opened, and the vacuum pump 11 is evacuated until the degree of vacuum in the vessel reaches about 5 × 10 ⁻⁶ Pa. After heating the substrate to 500 ° C., oxygen gas was introduced from the oxygen gas introduction tube 3 so that the oxygen atmosphere pressure was 1.33 Pa. By irradiating the 4th harmonic (266 nm) pulsed laser light emitted from the first Nd-YAG laser oscillator 9a to the magnesium-doped copper chromium oxide (CuCrO ₂ ) target 5c through the optical system 7a and the quartz window 4a, quartz A CuCrO ₂ thin film was deposited on the glass substrate 8.

The temperature of the quartz glass substrate 8 was room temperature, the energy density of the ablation laser was about 25 W / cm ² , and the thickness of the CuCrO ₂ thin film was about 150 nm. The same as Comparative Example 2 except that the quartz glass substrate 8 was heated during the deposition. FIG. 3 shows the results of measuring the resistance of the obtained CuCrO ₂ thin film by the four-end needle method.

As shown in FIG. 3, when the CuCrO ₂ thin film was deposited at room temperature, the crystallinity was low and the resistance was very large, which was unsuitable as a semiconductor film, but when formed by irradiating light as in Example 2, It turns out that resistance falls remarkably. In addition, as shown in FIG. 3, the characteristics of the CuCrO ₂ thin film can be widely controlled by controlling the laser irradiation energy. For example, in the case of 0.6 W / cm ² laser irradiation, the transparent substrate is heated to 500 ° C. Thus, it is possible to obtain the same characteristics as the CuCrO ₂ thin film of Comparative Example 4 produced in this way without heating.

Example 3
In Example 3, based on the results of Example 1 and Example 2, a case where a visible light transmitting semiconductor element is formed by stacking an n-type semiconductor film and a p-type semiconductor film to form a pn junction will be described. .
Hereinafter, a method of forming CuCrO ₂ / ZnO / ZnO (Al 1 wt%) on the quartz glass substrate 8 using the vapor deposition apparatus shown in FIG. 1 will be described. First, the quartz glass substrate 8 is placed in a predetermined position in the vacuum vessel 1, the exhaust valve 2 is opened, and the vacuum pump 11 is exhausted until the degree of vacuum in the vacuum vessel 1 becomes about 5 × 10 ⁻⁶ Pa. After that, oxygen gas was introduced from the oxygen gas introduction pipe 3 so that the oxygen atmosphere pressure was 0.133 Pa. Next, the 4th harmonic (266 nm) pulsed laser light emitted from the first Nd-YAG laser oscillation device 9a is irradiated to the aluminum-doped zinc oxide (AZO) target 5a through the optical system 7a and the light introduction window 4a, and the quartz glass is irradiated. An aluminum-doped zinc oxide thin film of about 200 nm was formed on the substrate 8 to form a transparent electrode layer. The temperature of the quartz glass substrate 8 was room temperature.

Next, the target is changed to a non-doped zinc oxide (ZnO) target 5b, the oxygen atmosphere pressure is 1.33 Pa, and the fourth harmonic (266 nm) pulse emitted from the first Nd-YAG laser oscillator 9a. A laser beam is irradiated onto the zinc oxide (ZnO) target 5b through the optical system 7a and the light introduction window 4a to deposit a non-doped zinc oxide film on the aluminum-doped zinc oxide thin film on the quartz glass substrate 8, and simultaneously with this deposition. The quartz glass substrate 8 being deposited was irradiated with pulsed laser light of the fourth harmonic (266 nm) emitted from the second Nd-YAG laser oscillation device 9b through the optical system 7b and the light introduction window 4b. The temperature of the quartz glass substrate 8 was room temperature. Further, the energy density of approximately 25W / cm ² ablation laser, the energy density of the substrate irradiated laser 0.6 W / cm ^2, the ZnO film thickness was approximately 150 nm.

Next, the target is changed to a magnesium-doped copper chrome oxide (CuCrO ₂ ) target 5c, and the oxygen atmosphere pressure is set to 0.266 Pa, and the fourth harmonics emitted from the first Nd-YAG laser oscillation device 9a ( 266nm) is irradiated onto the CuCrO ₂ target 5c through the optical system 7a and the light introduction window 4a to deposit copper chromium oxide on the zinc oxide thin film on the quartz glass substrate 8. The quartz glass substrate 8 in the center was irradiated with the fourth harmonic (266 nm) pulsed laser light emitted from the second Nd-YAG laser oscillation device 9b through the optical system 7b and the light introduction window 4b. The temperature of the quartz glass substrate 8 was room temperature. Also, the energy density of the ablation laser is about 25W / cm ^2, the energy density of the substrate irradiated laser is about 0.6 W / cm ^2, the thickness of the copper chromium oxide was about 150 nm.

FIG. 4 is a view showing the structure of CuCrO ₂ / ZnO / ZnO (Al1 wt%) / glass produced in Example 3. FIG. 5 is a diagram showing IV characteristics in CuCrO ₂ / ZnO / ZnO (Al1 wt%) / glass produced in Example 3, with a CuCrO ₂ film (p-type semiconductor) as a positive electrode and a ZnO film (n-type). The semiconducting pn junction was examined using the two-probe method with the negative electrode (semiconductor) as a negative electrode. FIG. 6 is a diagram showing a light transmission spectrum. As shown in FIG. 6, CuCrO ₂ / ZnO / ZnO (Al1 wt%) / glass produced in Example 3 is 50% or more in the visible light region. It can be seen that the transmittance is maintained and it is transparent in the visible light region.

Example 4
In Example 3, since a ZnO thin film was used for the lower electrode, it was necessary to prepare three targets for the lower electrode, for the n-type semiconductor, and for the p-type semiconductor. Since the characteristics of the ZnO thin film can be controlled by light irradiation in Example 1, a single target was used to form a ZnO thin film formed without irradiating the lower electrode and a ZnO thin film irradiated with light on the n-type semiconductor layer. The transmissive semiconductor element will be described.

Hereinafter, a method for forming a CuCrO ₂ / ZnO / ZnO film on the quartz glass substrate 8 using the vapor deposition apparatus shown in FIG. 1 will be described. First, the quartz glass substrate 8 is placed in a predetermined position in the vacuum container 1, the exhaust valve 2 is opened, and the vacuum pump 11 is evacuated until the degree of vacuum in the container becomes about 5 × 10 ⁻⁶ Pa. The oxygen gas was introduced from the oxygen gas introduction pipe 3 so that the oxygen atmosphere pressure was 0.133 Pa. Next, the 4th harmonic (266 nm) pulsed laser light emitted from the first Nd-YAG laser oscillation device 9a is irradiated to the non-doped zinc oxide (ZnO) target 5b through the optical system 7a and the light introduction window 4a, thereby producing quartz glass. A zinc oxide thin film of about 200 nm was formed on the substrate 8 to form a transparent lower electrode layer. The temperature of the quartz glass substrate 8 was room temperature.

Next, a fourth harmonic (266 nm) pulse laser emitted from the first Nd-YAG laser oscillator 9a using the same non-doped zinc oxide (ZnO) target 5b with an oxygen atmosphere pressure of 1.33 Pa. A zinc oxide (ZnO) target 5b is irradiated with light through the optical system 7a and the light introduction window 4a to deposit a non-doped zinc oxide film on the aluminum-doped zinc oxide thin film on the quartz glass substrate 8, and simultaneously with this deposition, The quartz glass substrate 8 being deposited was irradiated with the fourth harmonic (266 nm) pulsed laser light emitted from the second Nd-YAG laser oscillation device 9b through the optical system 7b and the light introduction window 4b. The temperature of the quartz glass substrate 8 was room temperature. Also, the energy density of the ablation laser is about 25W / cm ^2, the energy density of the substrate irradiated laser 0.6 W / cm ^2, the thickness of the zinc oxide thin film was about 150 nm.

Furthermore, the target was changed to a magnesium-doped copper chromium oxide (CuCrO ₂ ) target 5c, and the oxygen atmosphere pressure was 0.266 Pa, and the fourth harmonic (266 nm) emitted from the first Nd-YAG laser oscillation device 9a. ) Is irradiated onto the CuCrO ₂ target 5c through the optical system 7a and the light introduction window 4a to deposit copper chromium oxide on the zinc oxide thin film on the quartz glass substrate 8, and at the same time as this deposition, The quartz glass substrate 8 was irradiated with a 4th harmonic (266 nm) pulsed laser beam emitted from the second Nd-YAG laser oscillation device 9b through the optical system 7b and the light introduction window 4b. The temperature of the quartz glass substrate 8 was room temperature. Also, the energy density of the ablation laser is about 25W / cm ^2, the energy density of the substrate irradiated laser is about 0.6 W / cm ^2, the thickness of the zinc oxide thin film was about 150 nm.

FIG. 7 is a diagram showing IV characteristics of CuCrO ₂ / ZnO / ZnO / glass produced in Example 4. As shown in FIG. 7, a CuCrO ₂ film (p-type semiconductor) is used as a positive electrode, and a ZnO film (n When the semiconducting pn junction was examined using a two-probe method with a negative-type semiconductor) as the negative electrode, rectification was confirmed. Furthermore, according to the film forming method of Example 4, since the same zinc oxide target 5b can be used for the lower electrode layer and the n-type semiconductor film, the number of targets can be reduced and the cost can be reduced.

Comparative Example 5
A method for forming a CuCrO ₂ / ZnO / ZnO (Al 1 wt%) film on a quartz glass substrate 8 without performing light irradiation by a substrate irradiation laser using the vapor deposition apparatus shown in FIG. First, the quartz glass substrate 8 is placed in a predetermined position in the vacuum container 1, the exhaust valve 2 is opened, and the vacuum pump 11 is evacuated until the degree of vacuum in the container becomes about 5 × 10 ⁻⁶ Pa. Then, oxygen gas was introduced from the oxygen gas introduction tube 3 so that the oxygen atmosphere pressure was 0.133 Pa. Next, a 4th harmonic (266 nm) pulsed laser beam emitted from the first Nd-YAG laser oscillation device 9a is irradiated to the aluminum-doped zinc oxide (AZO) target 5a through the optical system 7a and the quartz window 4a, thereby producing a quartz glass substrate. An aluminum-doped zinc oxide thin film having a thickness of about 200 nm was formed on 8 to form a transparent lower electrode layer. The temperature of the quartz glass substrate was room temperature.

Next, the target is changed to a non-doped zinc oxide (ZnO) target 5b, the oxygen atmospheric pressure is 1.33 Pa, the quartz glass substrate 8 is not irradiated with laser, and the first Nd-YAG laser oscillation device 9a Non-doped zinc oxide on the aluminum-doped zinc oxide thin film on the quartz glass substrate 8 by irradiating the aluminum-doped zinc oxide target with the 4th harmonic (266 nm) pulsed laser beam emitted from the optical system 7a and the quartz window 4a. A film was deposited. The energy density of the ablation laser was about 25 W / cm ² and the thickness of the zinc oxide thin film was about 150 nm.

Next, the target is changed to a magnesium-doped copper chromium oxide (CuCrO ₂ ) target 5c, the oxygen atmospheric pressure is set to 0.266 Pa, the quartz glass substrate 8 is not irradiated with laser, and the first Nd-YAG The CuCrO ₂ target 5c is irradiated with the 4th harmonic (266nm) pulsed laser light emitted from the laser oscillation device 9a through the optical system 7a and the quartz window 4a to oxidize copper chromium on the zinc oxide thin film on the quartz glass substrate 8. Things were deposited. The temperature of the quartz glass substrate 8 was room temperature. The energy density of the ablation laser was about 25 W / cm ² and the film thickness of the copper chrome oxide thin film was about 150 nm.

As shown in the light transmission spectrum of FIG. 6, it was confirmed that CuCrO ₂ / ZnO / ZnO (Al1 wt%) / glass formed in Comparative Example 5 had a visible light region of 50% or more. However, as shown in the IV characteristics of FIG. 8, CuCrO ₂ / ZnO / ZnO (Al1 wt%) / glass formed in Comparative Example 5 could not confirm the rectifying action.

Comparative Example 6
Using the apparatus shown in FIG. 1, a method of forming CuCrO ₂ / ZnO / ZnO (Al1 wt%) on a quartz glass substrate 8 by performing post-thermal annealing after film formation without performing light irradiation with a substrate irradiation laser. Will be described. First, the quartz glass substrate 8 is placed in a predetermined position in the vacuum container 1, the exhaust valve 2 is opened, and the vacuum pump 11 is evacuated until the degree of vacuum in the container becomes about 5 × 10 ⁻⁶ Pa. Then, oxygen gas was introduced from the oxygen gas introduction pipe (stainless steel pipe) 3 so that the oxygen atmosphere pressure was 0.133 Pa. Next, a 4th harmonic (266 nm) pulsed laser beam emitted from the first Nd-YAG laser oscillation device 9a is irradiated to the aluminum-doped zinc oxide (AZO) target 5a through the optical system 7a and the quartz window 4a, thereby producing a quartz glass substrate. An aluminum-doped zinc oxide thin film having a thickness of about 200 nm was formed on 8 to form a transparent lower electrode layer. The temperature of the quartz glass substrate 8 was room temperature.

Next, the target is changed to a non-doped zinc oxide (ZnO) target 5b, the oxygen atmospheric pressure is 1.33 Pa, the quartz glass substrate 8 is not irradiated with laser, and the first Nd-YAG laser oscillation device 9a Non-doped zinc oxide on the aluminum-doped zinc oxide thin film on the quartz glass substrate 8 by irradiating the aluminum-doped zinc oxide target with the 4th harmonic (266 nm) pulsed laser beam emitted from the optical system 7a and the quartz window 4a. A film was deposited. The energy density of the ablation laser was about 25 W / cm ² and the thickness of the zinc oxide thin film was about 150 nm.

In addition, the target was changed to magnesium-doped copper chromium oxide (CuCrO ₂ ) 5c, the oxygen atmosphere pressure was 0.266 Pa, and the quartz glass substrate 8 was not irradiated with laser, and the first Nd-YAG laser oscillation 4th harmonic (266nm) pulsed laser light emitted from device 9a is used as optical system 7a.
Then, the CuCrO ₂ target 5c was irradiated through the quartz window 4a to deposit copper chromium oxide on the zinc oxide thin film on the quartz glass substrate 8. The temperature of the quartz glass substrate 8 was room temperature. The energy density of the ablation laser was about 25 W / cm ² and the film thickness of the copper chrome oxide thin film was about 150 nm. Then, CuCrO ₂ / ZnO / ZnO (Al 1 wt%) formed on the quartz glass substrate 8 was annealed at 500 ° C. for 10 minutes so that the gas atmosphere was 0.266 Pa in the vacuum vessel 1.

FIG. 9 is a diagram showing IV characteristics in CuCrO ₂ / ZnO / ZnO (Al1 wt%) / glass produced in Comparative Example 6, with a CuCrO ₂ film (p-type semiconductor) as a positive electrode and a ZnO film (n-type semiconductor). Using a two-probe method with a negative electrode as the negative electrode, a semiconducting pn junction was examined, and a rectifying action as shown in the figure was confirmed. Further, as shown in the light transmission spectrum of FIG. 6, it was confirmed that the visible light transmittance was 50% or more.

  As is clear from comparison with the above-described examples and comparative examples, a visible light transmitting semiconductor element can be produced without heating the quartz glass substrate 8. In the above embodiment, the case where the semiconductor film is deposited using laser ablation has been described. However, the present invention is not limited to this.

FIG. 1 is a diagram showing an example of a vapor deposition apparatus used for producing a visible light transmitting semiconductor element of the present invention. FIG. 4 is a diagram showing the results of measuring resistance of the zinc oxide thin films obtained in Example 1, Comparative Example 1 and Comparative Example 2 by a four-end needle method. FIG. 6 is a diagram showing the results of measuring resistance of the zinc oxide thin films obtained in Example 2, Comparative Example 3 and Comparative Example 4 by a four-end needle method. 4 is a diagram showing a configuration of CuCrO ₂ / ZnO / ZnO (Al1 wt%) / glass produced in Example 3. FIG. FIG. 4 is a diagram showing IV characteristics of CuCrO ₂ / ZnO / ZnO (Al1 wt%) / glass produced in Example 3. FIG. 6 is a graph showing light transmission spectra of Example 3, Comparative Example 5 and Comparative Example 6. FIG. 6 is a diagram showing IV characteristics of CuCrO ₂ / ZnO / ZnO / glass produced in Example 4. FIG. 6 is a view showing IV characteristics of CuCrO ₂ / ZnO / ZnO (Al1 wt%) / glass produced in Comparative Example 5. FIG. 6 is a diagram showing IV characteristics of CuCrO ₂ / ZnO / ZnO (Al1 wt%) / glass produced in Comparative Example 6.

Explanation of symbols

1 Vacuum container
2 Exhaust valve
3 Gas inlet pipe
4a, 4b Light introduction window
5a ZnO target
5b Al-doped ZnO target
5c CuCrO ₂ target
6a, 6b UV laser beam
7a, 7b optics
8 Transparent substrate
9a 1st Nd-YAG laser oscillator
9b Second Nd-YAG laser oscillator
10 Sample holder
11 Vacuum pump
12 Oxygen gas supply source
13 Mass flow controller

Claims (14)

  A visible light transmitting semiconductor element comprising: a transparent substrate; and a semiconductor film formed while irradiating light from a light emitting device during deposition of a material containing a semiconductor composition on the transparent substrate.   A transparent substrate, a semiconductor film formed while irradiating light from a light-emitting device during deposition of a material containing the composition of the n-type semiconductor on the transparent substrate, and a composition of the p-type semiconductor on the semiconductor film A visible light transmitting semiconductor element comprising: a semiconductor film formed while irradiating light from a light emitting device during material deposition.   A transparent substrate, a semiconductor film formed while irradiating light from a light-emitting device during deposition of a material containing the composition of the p-type semiconductor on the transparent substrate, and an n-type semiconductor composition on the semiconductor film A visible light transmitting semiconductor element comprising: a semiconductor film formed while irradiating light from a light emitting device during material deposition.   4. The visible light transmitting semiconductor according to claim 1, wherein a wavelength of light emitted from the light emitting device is shorter than an absorption edge of the semiconductor film. element.   5. The visible light transmitting semiconductor element according to claim 1, wherein the semiconductor film is made of a semiconductor having a band gap of 2.5 eV or more. The semiconductor _{film, ZnO, SnO 2, In 2} O 3, CdIn 2 O 4, MgIn 2 O 4, ZnGa 2 O 4, InGaZnO 4, GaN, copper aluminum oxide, copper gallium oxide, copper indium oxide, 6. The material according to claim 1, wherein the main component is a material selected from copper chromium oxide, copper scandium oxide, copper yttrium oxide, silver indium oxide, strontium copper oxide, and gallium nitride. The visible light transmissive semiconductor element according to any one of claims.   7. The semiconductor film according to claim 6, wherein one or more materials of Mg, Ca, Sr, Sb, B, Al, Ga, In, N, Ni, Sn, or Cr are added. Visible light transmissive semiconductor element.   7. The visible light transmitting electrode layer is formed between the transparent substrate and the semiconductor film formed on the transparent substrate, according to any one of claims 1 to 6. The visible light transmitting semiconductor element described. The visible light transmission electrode _{layer, ZnO, SnO 2, In 2} O 3, CdIn 2 O 4, MgIn 2 O 4, ZnGa 2 O 4, InGaZnO 4, GaN, copper aluminum oxide, copper gallium oxide, copper indium 9. The visible light according to claim 8, characterized by comprising as a main component a material selected from an oxide, a copper chromium oxide, a copper scandium oxide, a copper yttrium oxide, a silver indium oxide, and a strontium copper oxide. Transparent semiconductor element.   The visible light transmitting electrode layer is characterized in that one or more materials of Mg, Ca, Sr, Sb, B, Al, Ga, In, N, Ni, Sn or Cr are added. 10. A visible light transmitting semiconductor element according to 9,   4. The visible light according to claim 2, wherein a visible light transmitting intrinsic semiconductor layer or a visible light transmitting insulating layer is formed between the p-type semiconductor film and the n-type semiconductor film. Transparent semiconductor element. The visible light transmitting intrinsic semiconductor is characterized by comprising as a main component a material selected from ZnO, SnO ₂ , In ₂ O ₃ , CdIn ₂ O ₄ , MgIn ₂ O ₄ , ZnGa ₂ O ₄ , InGaZnO ₄ and GaN. 12. The visible light transmissive semiconductor element according to claim 11. The visible light transmission insulating _{layer, SiO 2, SnO 2, B} 2 O 3, P 2 O 5, ZnO, Y 2 O 3, ZrO 2, HfO 2, CeO, MgO, from Bi ₂ O ₃ and TiO ₂ 13. The visible light transmissive semiconductor element according to claim 11 or 12, wherein a selected material is a main component. 14. The visible light transmitting semiconductor element according to claim 1, wherein the temperature of the transparent substrate is controlled when light is emitted from the light emitting device. Production method.

Images