WO2009157512A1 - Capteur de rayonnement ultraviolet - Google Patents

Capteur de rayonnement ultraviolet Download PDF

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Publication number
WO2009157512A1
WO2009157512A1 PCT/JP2009/061614 JP2009061614W WO2009157512A1 WO 2009157512 A1 WO2009157512 A1 WO 2009157512A1 JP 2009061614 W JP2009061614 W JP 2009061614W WO 2009157512 A1 WO2009157512 A1 WO 2009157512A1
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Prior art keywords
ultraviolet
optical fiber
photodetector
fiber cable
light receiving
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PCT/JP2009/061614
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English (en)
Japanese (ja)
Inventor
武 瀬木
恵司 金田
正伸 日高
重男 大平
直樹 新井
Original Assignee
東海東洋アルミ販売株式会社
日本軽金属株式会社
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Publication of WO2009157512A1 publication Critical patent/WO2009157512A1/fr

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/0248—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies
    • H01L31/0256—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by the material
    • H01L31/0264—Inorganic materials
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/42—Coupling light guides with opto-electronic elements
    • G02B6/4201—Packages, e.g. shape, construction, internal or external details
    • G02B6/4202—Packages, e.g. shape, construction, internal or external details for coupling an active element with fibres without intermediate optical elements, e.g. fibres with plane ends, fibres with shaped ends, bundles
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/42—Coupling light guides with opto-electronic elements
    • G02B6/4201—Packages, e.g. shape, construction, internal or external details
    • G02B6/4204—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms
    • G02B6/4206—Optical features
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/42—Coupling light guides with opto-electronic elements
    • G02B6/4201—Packages, e.g. shape, construction, internal or external details
    • G02B6/4204—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms
    • G02B6/4214—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/08—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors
    • H01L31/10—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors characterised by potential barriers, e.g. phototransistors
    • H01L31/101—Devices sensitive to infrared, visible or ultraviolet radiation
    • H01L31/102—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier
    • H01L31/108—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier the potential barrier being of the Schottky type
    • H01L31/1085—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier the potential barrier being of the Schottky type the devices being of the Metal-Semiconductor-Metal [MSM] Schottky barrier type

Definitions

  • the present invention relates to an ultraviolet sensor, and more particularly to an ultraviolet sensor suitable for continuous monitoring and excellent in durability and electromagnetic noise resistance.
  • This application claims priority based on Japanese Patent Application No. 2008-167378 for which it applied to Japan on June 26, 2008, and uses the content here.
  • Ultraviolet emitting tools for example, ultraviolet lamps
  • ultraviolet light emitting tools that emit ultraviolet light having a short wavelength of 254 nm or less have become important in applications such as water purification, sterilization and sterilization in the food and medical fields. Since this type of ultraviolet emitting tool is a consumable item, it is important to determine the lifetime (time to replace the ultraviolet emitting tool).
  • a life time is set in advance as a guideline for replacing the ultraviolet emitting tool (for example, 2000 hours), and after using the set lifetime, I was trying to replace it.
  • the actual life of the ultraviolet light emitting device is not constant for each ultraviolet light emitting device, it may be shorter or longer than the set life.
  • the lifetime of the ultraviolet emitting tool becomes shorter than the set lifetime, there is a problem that the ultraviolet emitting tool continues to be used without generating ultraviolet rays. Therefore, if there is an apparatus capable of continuously monitoring the ultraviolet emitting tool, there is no concern that the ultraviolet emitting tool will reach the end of its life before replacement. Furthermore, when this apparatus is used, when the actual life of the ultraviolet emitting tool becomes longer than the set lifetime, it can be used efficiently until the ultraviolet emitting tool is consumed, resulting in an economic advantage.
  • UV sensors using semiconductors such as silicon (Si) and aluminum gallium nitride (AlGaN) are known as conventional devices for measuring the power of ultraviolet rays generated from ultraviolet emitting tools.
  • a filter is used to select a measurement wavelength. Therefore, in the short wavelength region of wavelength 254 nm or less, the bandwidth of the received light spectrum is wide, and this filter is easily deteriorated by ultraviolet rays, and the received light wavelength shifts with this deterioration. Calibration of the UV sensor is required.
  • the parts used around the filter have restrictions due to heat resistance (usually a use temperature of 40 ° C. or lower). In other words, it is necessary to frequently adjust the ultraviolet ray measurement location so that the temperature of these components does not become higher than the operating temperature.
  • AlGaN As a photodetector material having sensitivity in a short wavelength region of 254 nm or less, there is AlGaN (see, for example, Patent Document 1) other than silicon.
  • this AlGaN has a problem that it is deteriorated by oxidation. For this reason, it is difficult to monitor ultraviolet rays continuously and stably for a long period of time.
  • Phototube-type sensors also have sensitivity in this wavelength range, but also have sensitivity in the wavelength band of ultraviolet rays contained in sunlight (not solar blinds), sensitivity is likely to fluctuate, and heat resistance is not good.
  • the ultraviolet emitting tool In order to manage the life of the ultraviolet emitting tool based on quantitative data, it is essential to measure the ultraviolet power at the local area where the ultraviolet emitting tool is used. However, in reality, it cannot be realized due to problems such as the shape and heat resistance of the light receiving portion of the ultraviolet sensor and the life of the sensing portion. Moreover, if the ultraviolet light receiving part and the sensor head part are integrated as in the case of a conventional ultraviolet sensor, the remote monitoring becomes insufficient, the ultraviolet ray measurement location is restricted, and the monitoring is not always satisfactory. There is a problem that you can not.
  • the present invention has been made in order to solve such a conventional problem, and by continuously monitoring the life of the ultraviolet emitting tool, it is possible to obtain a predetermined replacement time for the ultraviolet emitting tool. It is an object of the present invention to provide an ultraviolet sensor that enables replacement of the ultraviolet emitting tool in accordance with the actual wear time and enables remote monitoring without restricting the ultraviolet measurement point.
  • An ultraviolet sensor of the present invention includes a photodetector that detects ultraviolet rays and one or a plurality of optical fiber cables that propagate the ultraviolet rays toward the photodetector, and the optical fiber cable receives the ultraviolet rays.
  • the photodetector includes a ⁇ -Ga 2 O 3 crystal and electrodes formed on the front and back surfaces of the ⁇ -Ga 2 O 3 crystal, respectively. According to the ultraviolet sensor as described in said (1), a photodetector can be arrange
  • ⁇ -Ga 2 O 3 crystal is excellent in durability and heat resistance, and is already an oxide, so there is no fear of deterioration due to oxidation.
  • the ultraviolet sensor described in the above (1) the shift of the light reception wavelength is difficult to occur. Therefore, it is possible to reduce or eliminate the calibration of the ultraviolet sensor that is performed for the shift of the light receiving wavelength. As a result, the power of the ultraviolet emitting tool can be continuously monitored, and the ultraviolet emitting tool can be replaced before the ultraviolet emitting tool is consumed and the generation of ultraviolet rays is eliminated.
  • the photodetector can be arranged apart from the ultraviolet emitting tool in a state where the light receiving unit is arranged in the vicinity of the ultraviolet emitting tool, so that remote monitoring is possible.
  • the electrode formed on the surface of the ⁇ -Ga 2 O 3 crystal is a Schottky electrode, and the ultraviolet light propagated through the optical fiber cable is converted into the shot sensor. It may be introduced into the key electrode.
  • ultraviolet rays can be received by the entire surface of the depletion layer of ⁇ -Ga 2 O 3 crystal extending under the Schottky electrode. Therefore, the utilization efficiency of the ⁇ -Ga 2 O 3 crystal is increased.
  • the ultraviolet sensor according to (1) may continuously monitor the ultraviolet light. (4) You may use the ultraviolet sensor as described in said (1) for the illumination intensity measurement of the ultraviolet-ray emitting tool which wash
  • the ultraviolet light in the incident direction that is largely shifted laterally from the optical axis of the ultraviolet light emitted from the ultraviolet light emitting tool can be efficiently received by the light receiving unit.
  • the light receiving unit may have a slope inclined with respect to the optical axis of the ultraviolet light. In the case of the above (8), the ultraviolet light incident from the side with respect to the inclined surface of the light receiving unit is reflected by this inclined surface and is incident on the optical fiber cable.
  • a condensing lens may be disposed in the light receiving unit. In the case of (9) above, ultraviolet rays can be more effectively incident on the optical fiber cable.
  • the light receiving unit may be a V-groove formed in the optical fiber cable. In the case of (10) above, ultraviolet light can be incident on the optical fiber cable from the side of the optical fiber cable.
  • the power of the ultraviolet emitting tool can be continuously monitored, and the ultraviolet emitting tool can be replaced before the ultraviolet emitting tool is consumed and the generation of ultraviolet rays is eliminated. Yes. Therefore, continuous generation of ultraviolet rays can be maintained.
  • the deterioration of the UV sensor due to the heat generated by the UV emitting tool and electromagnetic waves is suppressed, and the heat resistance and durability requirements for the UV sensor are reduced. Therefore, calibration of the UV sensor due to the shift of the received light wavelength can be reduced or eliminated.
  • the photodetector can be installed apart from the ultraviolet emitting tool in a state where the light receiving unit is arranged in the vicinity of the ultraviolet emitting tool, so that the ultraviolet emitting tool can be remotely monitored.
  • the sensitivity of the ultraviolet sensor in an Example is a graph which shows irradiation power dependence. It is a graph which shows the electromotive current and irradiation power of the photodetector in the Example. It is a graph which shows the measurement result of the dark current in the Example.
  • FIG. 1 is a diagram illustrating a schematic configuration example of an ultraviolet sensor according to an embodiment of the present invention.
  • An ultraviolet sensor 1 shown in FIG. 1 includes a photodetector 2 that detects ultraviolet rays and an optical fiber cable 3 that propagates ultraviolet rays toward the photodetector 2, and the optical fiber cable 3 emits ultraviolet rays emitted from an ultraviolet emitting tool L. It has the light-receiving part 4 which receives light.
  • FIG. 2 shows an example of the configuration of the photodetector 2 and the vicinity thereof in more detail.
  • the photodetector 2 includes a ⁇ -Ga 2 O 3 ( ⁇ -type gallium oxide) crystal 10 and electrodes formed on the front and back thereof. That is, on the surface of the ⁇ -Ga 2 O 3 crystal 10, together with the Schottky electrode 11 of the ultraviolet ray for detection is formed on the back surface of the ⁇ -Ga 2 O 3 crystal 10 corresponds to the Schottky electrode 11
  • the ohmic electrode 12 is formed at the position where the A pad electrode 13 for wiring is formed on the Schottky electrode 11.
  • a test Schottky electrode 14 and an ohmic electrode 15 are formed on the front surface and the back surface of the ⁇ -Ga 2 O 3 crystal 10, respectively.
  • Figure 4A is ⁇ -Ga 2 O 3 each electrode of the crystal 10 surface shows the arrangement of (the Schottky electrode 11, the Schottky electrode 14 of the pad electrodes 13 and the test),
  • FIG. 4B is ⁇ -Ga 2 O 3 crystal 10 back surface The arrangement of each electrode (the ohmic electrode 12 and the test ohmic electrode 15) is shown.
  • the photodetector 2 is accommodated in the housing 6.
  • the housing 6 is made of a material that does not allow ultraviolet rays to pass through. It is desirable that the ultraviolet rays to be measured be introduced into the housing 6 only by propagation through the optical fiber cable 3. From the viewpoint of electrostatic shielding of the photodetector 2 housed inside the housing 6, the housing 6 is preferably made of a conductive material.
  • the housing 6 can be formed of a metal such as stainless steel, aluminum, brass, iron, or nickel.
  • the housing 6 may be configured such that a plurality of members are combined and integrated after the photo detector 2 is accommodated.
  • the photodetector 2 is fixed on a support plate 20 made of sapphire, quartz or the like using a binder 21 such as silver (Ag) paste.
  • the support plate 20 is die bonded to the bottom surface of the housing 6.
  • An opening 7 through which the optical fiber cable 3 is inserted is formed on the top surface of the housing 6.
  • the optical fiber cable 3 inserted through the opening 7 is arranged such that the emission part 5 faces the Schottky electrode 11 of the photodetector 2.
  • the emitting unit 5 for example, an end surface of the optical fiber cable 3 that is polished perpendicularly to the optical axis direction (the vertical direction in FIG. 2) can be used.
  • the upper surface of the Schottky electrode 11 serves as the light receiving surface 11r of the photodetector 2, and the photodetector 2 is disposed so that the light receiving surface 11r faces the light emitting portion 5 of the optical fiber cable 3.
  • a pair of leads 24 and 25 serving as terminals of the photodetector 2 are drawn out from the bottom surface side of the housing 6 to the outside of the housing 6.
  • the pad electrode 13 and the ohmic electrode 12 of the photodetector 2 are electrically connected to one end of a pair of leads 24 and 25 via a pair of bonding wires 22 and 23, respectively.
  • a gold (Au) wire having a diameter of 25 ⁇ m is used for the pair of bonding wires 22 and 23.
  • a power source 8 such as a battery and an ammeter 9 are connected between the pair of leads 24 and 25. By measuring the current value using this ammeter 9, it is possible to detect ultraviolet rays and measure power.
  • the ⁇ -Ga 2 O 3 crystal 10 used in the photodetector 2 has a large sensitivity near a wavelength of 254 nm and is excellent in durability and heat resistance. Since ⁇ -Ga 2 O 3 is an oxide semiconductor having a high melting point of 1740 ° C. and a wide band gap of 4.7 to 4.9 eV, it becomes a solar blind sensor. Since ⁇ -Ga 2 O 3 is already an oxide, there is no fear of deterioration due to oxidation. Therefore, it is suitable for measuring the ultraviolet power in the ultraviolet wavelength region, particularly in the wavelength region of 200 to 254 nm.
  • the ⁇ -Ga 2 O 3 crystal 10 may be a single crystal of ⁇ -Ga 2 O 3 , a twin crystal or a polycrystal, and in either case, the same effect is obtained.
  • the ⁇ -Ga 2 O 3 single crystal 10 having excellent crystal quality can be manufactured by the following method.
  • Ga 2 O 3 powder having a purity of 4N (99.99% or more) is enclosed in a rubber tube, molded with a rubber press, sintered in an electric furnace at 1500 ° C. for 10 hours, A single crystal is grown by the FZ (Floating Zone) method using the bonded body as a raw material rod.
  • the single crystal growth conditions include a growth rate of 5 to 10 mm / h, a dry air atmosphere, and a pressure of 1 atm.
  • the ⁇ -Ga 2 O 3 single crystal 10 thus produced is sliced with a wire saw or the like in a plane parallel to the (100) plane having the strongest cleaving property, and this (100) plane is then subjected to chemical mechanical polishing (CMP). : Mirror polishing with Chemical Mechanical Polishing) to process into a wafer with a thickness of 0.4 to 0.5 mm.
  • CMP chemical mechanical polishing
  • This ⁇ -Ga 2 O 3 single crystal 10 has a specific resistance of 0.1 to 0.5 ⁇ cm and a carrier density of about 10 17 to 10 18 cm ⁇ 3 and is electrically conductive. Using this single crystal, the photodetector 2 can be produced without epitaxial growth.
  • FIG. 3 shows a cross-sectional structure of the photodetector 2.
  • a Schottky electrode 11 and an ohmic electrode 12 are formed on the front surface and the back surface of the ⁇ -Ga 2 O 3 crystal 10 respectively, so that a vertical Schottky diode is configured in the photodetector 2.
  • a depletion layer 10a is formed immediately below the Schottky electrode 11 on the surface, and a conductive layer 10b is formed therebelow.
  • the Schottky electrode 11 is formed of a thin electrode having a light receiving surface 11r formed on the surface thereof and having translucency with respect to ultraviolet rays to be detected.
  • the depletion layer it is preferable to use a depletion layer by Schottky contact instead of a pn junction. As a result, the structure of the photodetector 2 becomes an MSM (Metal-Semiconductor-Metal) type.
  • MSM Metal-Semiconductor-Metal
  • MSM type has horizontal structure and vertical structure.
  • a horizontal structure it is necessary to form a comb-shaped electrode by using photolithography or the like. Since it is difficult to increase the area of the comb-shaped electrode, and the depletion layer is formed only directly below the comb-shaped electrode, the utilization efficiency of gallium oxide decreases.
  • a vertical structure MSM type is employed as the structure of the photodetector 2.
  • the photodetector 2 sensor unit
  • the photodetector 2 only forms the Schottky electrode 11 on the surface of the ⁇ -Ga 2 O 3 crystal 10 and the ohmic electrode 12 on the back surface.
  • this vertical structure can receive ultraviolet light over the entire surface of the depletion layer 10a extending under the Schottky electrode 11, so that the utilization efficiency of the ⁇ -Ga 2 O 3 crystal 10 is increased.
  • the structure since it is not necessary to produce a comb-shaped electrode like a horizontal structure, the structure is simple and the manufacturing process is simple.
  • the ⁇ -Ga 2 O 3 single crystal 10 is washed in the order of hydrofluoric acid, sulfuric acid, acetone, ethanol, and pure water, and heat treatment is performed.
  • the purpose of the heat treatment is to recover defects such as oxygen vacancies remaining in the single crystal after crystal growth.
  • the heat treatment is preferably performed in an oxygen atmosphere at 1100 ° C. for 3 to 24 hours. The reason why the oxygen atmosphere is used is to replenish oxygen vacancies generated when the ⁇ -Ga 2 O 3 single crystal 10 is grown.
  • a protective film is formed on the surface of the ⁇ -Ga 2 O 3 single crystal 10.
  • a mounting wax used for fixing the analysis sample is used for the formation of the protective film. Since the mounting wax starts to melt from around 100 ° C., if the melted wax is applied to the slide glass, and the ⁇ -Ga 2 O 3 single crystal 10 is pressed against the slide glass coated with this wax and then cooled, a protective film Can be easily prepared.
  • Plasma irradiation on the back surface of ⁇ -Ga 2 O 3 single crystal 10 In order to make ohmic contact with the back surface of the ⁇ -Ga 2 O 3 single crystal 10, plasma irradiation is performed for the purpose of improving conductivity and reducing resistance. This is to forcibly generate defects and improve electrical conductivity due to generation of carrier electrons.
  • the plasma low-pressure glow discharge using residual gas can be used. It is preferable that the ion current is several hundred ⁇ A, and the current of the entire apparatus is 5 to 10 mA.
  • the irradiation time is preferably 20 to 40 minutes, more preferably about 30 minutes.
  • Schottky electrodes 11 and 14 gold (Au), platinum (Pt), or the like, which is a metal having a high work function, is used for an n-type semiconductor. After nickel (Ni) is deposited on the surface of ⁇ -Ga 2 O 3 single crystal 10 to a thickness of 2 to 5 nm (more preferably 2 nm), Au or Pt is deposited to a thickness of 6 to 10 nm, and Au / Ni or Pt / Ni is deposited. A semitransparent or transparent electrode is prepared.
  • the Schottky electrodes 11 and 14 may be made of Au or Pt alone without inserting a Ni layer.
  • the Schottky electrodes 11 and 14 As a material metal of the Schottky electrodes 11 and 14, in addition to Au and Pt, aluminum (Al), cobalt (Co), germanium (Ge), tin (Sn), indium (In), tungsten (W), molybdenum (Mo ), Chromium (Cr), copper (Cu), and the like.
  • Al aluminum
  • Co cobalt
  • germanium Ge
  • tin germanium
  • Sn tin
  • In indium
  • Mo molybdenum
  • Cr Chromium
  • Cu copper
  • the size of the Schottky electrode 11 is preferably 1 to 5 mm ⁇ , and more preferably 3 to 4 mm ⁇ . As the size of the Schottky electrode 11 is larger, the light receiving surface 11r can be enlarged.
  • a wiring pad electrode 13 is formed on the Schottky electrode 11.
  • Ni is deposited on the light receiving surface 11r with a thickness of 3 to 10 nm (more preferably 4 to 6 nm), and then Au or Pt is deposited with a thickness of 80 to 150 nm (more preferably 80 to 100 nm).
  • the size of the pad electrode 13 is preferably 0.05 to 1.5 mm ⁇ .
  • the structure is a pigtail type in which ultraviolet light received by the light receiving unit 4 at the tip of the optical fiber cable 3 is transmitted by the optical fiber cable 3 and detected by the photodetector 2. Since the optical fiber cable 3 is not affected by electromagnetic waves, it is not necessary to shield the surroundings with metal unlike the photodetector 2. Note that a ⁇ -Ga 2 O 3 single crystal, instead of a ⁇ -Ga 2 O 3 twin crystal or a polycrystal, can be similarly used.
  • the optical fiber cable 3 it is preferable to use a silica-based optical fiber in order to efficiently transmit ultraviolet rays in the measurement wavelength region.
  • the core diameter is preferably about 200 to 600 ⁇ m, and an extremely large one is used as compared with a general communication optical fiber.
  • the emitting portion 5 of the optical fiber cable 3 and the Schottky electrode 11 of the photodetector 2 can be directly coupled only through the atmosphere in the housing 6. For this reason, it is not necessary to provide the casing 6 with a member made of a material that transmits ultraviolet rays, such as a window material. Note that a window material may be provided depending on the applied ultraviolet sensor from the viewpoint of sealing the photodetector 2 and the emission part 5 of the optical fiber cable 3 in the housing 6.
  • an optical fiber bundle including a plurality of optical fiber cables 3 can be used as the optical fiber cable 3.
  • optical fiber bundles in which a plurality of optical fiber cables 3 are arranged linearly (in a line), or in a planar shape, and any of them can be used.
  • the optical fiber bundle it is possible to introduce ultraviolet rays into the light receiving surface 11r in a wider range as compared with the case of using one optical fiber cable (see FIG. 5A).
  • the light receiving portion 4 of the optical fiber cable 3 can be formed by processing the tip of the optical fiber cable 3 as shown in FIGS. 6A to 6C, for example.
  • FIG. 6A shows the end of the core 31 exposed by removing the protective coating 33 and the clad 32 of the optical fiber cable 3 on an end face 34 perpendicular to the optical axis.
  • FIG. 6B shows the tip of the core 31 exposed by removing the protective coating 33 and the clad 32 of the optical fiber cable 3 in a conical shape 35. In this case, it is possible to efficiently receive even the ultraviolet rays in the incident direction that are largely shifted laterally from the optical axis.
  • FIG. 6A shows the end of the core 31 exposed by removing the protective coating 33 and the clad 32 of the optical fiber cable 3 on an end face 34 perpendicular to the optical axis.
  • FIG. 6B shows the tip of the core 31 exposed by removing the protective coating 33 and the clad 32 of the optical fiber cable 3 in a conical shape 35.
  • FIG. 6C shows a case where the tip of the core 31 exposed by removing the protective coating 33 and the clad 32 of the optical fiber cable 3 is a slope.
  • the ultraviolet light incident from the side with respect to the wedge-shaped portion 36 at the tip is reflected by the inclined surface and incident on the optical fiber cable 3.
  • a reflective portion 37 such as an aluminum vapor deposition film on this slope.
  • the structure of the light receiving unit 4 shown in FIG. 7 is such that a condensing lens 38 is attached to the tip of the optical fiber cable 30. It is preferable to use a cylindrical lens such as a GRIN lens as the condenser lens 38 because it can be directly fixed to the tip of the optical fiber cable 30 by adhesion or fusion.
  • the structure of the light receiving unit 4 shown in FIG. 8 is such that a V-groove 39 is formed on the side surface of the optical fiber cable 30 so that ultraviolet rays can be incident from the side of the optical fiber cable 30 through the V-groove 39. is there.
  • a plurality of light receiving portions 4 can be provided by the plurality of optical fiber cables 3. If the optical fiber bundle is integrated in the light receiving unit 4, the number of ultraviolet measurement points by one ultraviolet sensor 1 is one, but the incident sectional area in the light receiving unit 4 can be increased. In this case, the incident directions directed by the respective light receiving units 4 may be aligned in the same direction. Moreover, if each light-receiving part 4 is arrange
  • a plurality of optical fiber cables 3 are arrayed on the emission unit 5 side, while the optical fiber cable 3 is branched in the middle and separated on the light receiving unit 4 side. You can also. In this case, the total amount of ultraviolet power at a plurality of locations can be measured using one ultraviolet sensor 1.
  • the ultraviolet sensor 1 of the present embodiment since the distance between the light receiving unit 4 and the photodetector 2 can be secured by the optical fiber cable 3, the ultraviolet sensor 1 (photodetector 2) caused by heat generated by the ultraviolet emitting tool L, electromagnetic waves, or the like. ) Degradation can be suppressed. Furthermore, since the heat resistance and durability requirements for the ultraviolet sensor 1 (photodetector 2) are reduced, the shift of the light receiving wavelength is less likely to occur, and the number of calibrations of the ultraviolet sensor can be reduced or eliminated. . Thereby, continuous monitoring can be realized.
  • the power of the ultraviolet ray emitting tool L is continuously monitored, so that the ultraviolet ray emitting tool can be replaced before the ultraviolet ray emitting tool L is consumed and no ultraviolet ray is generated. Therefore, continuous generation of ultraviolet rays from the ultraviolet emitting tool L can be maintained. Furthermore, since the ultraviolet rays propagate through the optical fiber cable 3, the optical fiber is not limited by the positional relationship between the light receiving unit 4 and the ultraviolet ray measurement location (there is no need to provide the photodetector 2 in the immediate vicinity of the ultraviolet ray measurement location). The photodetector 2 can be freely installed via the cable 3. As a result, the ultraviolet emitting tool L can be monitored remotely.
  • the photodetector 2 can be arranged outside the water tank, clean room, or the like where the ultraviolet light emitting tool L is provided. For this reason, deterioration of the ultraviolet sensor 1 (photodetector 2) due to heat generation or electromagnetic waves of the ultraviolet emitting tool L described above does not occur, and the ultraviolet emitting tool L can be monitored stably for a long period of time. Moreover, since ultraviolet rays are cut according to the wire diameter of the optical fiber cable 3, the illuminance to the photodetector 2 is reduced. Thereby, the deterioration of the photodetector 2 due to ultraviolet irradiation is further reduced, and the durability of the ultraviolet sensor 1 is improved.
  • the ultraviolet illuminance can be measured in a narrow place. Moreover, it becomes possible to make only the optical fiber cable 3 a consumable item. In this case, only the photodetector 2 is sealed, a sealing window cap is provided on the housing 6, and the optical fiber cable 3 is connected to the sealing window cap. Therefore, it is not necessary to perform sealing at the introduction portion (opening portion 7) for introducing the optical fiber cable 3 into the housing 6. As a result, the sealing life in the housing 6 is improved.
  • the ultraviolet sensor of this embodiment can also be suitably used for illuminance measurement of an ultraviolet emitting tool that cleans water.
  • the ultraviolet-ray emitting tool which sterilizes or sterilizes in the foodstuffs and the medical field.
  • it is applicable not only to these uses but also to illuminance measurement of ultraviolet emitting tools such as printing, semiconductor, observation, resist exposure, adhesion, and molding.
  • Gallium oxide powder having a purity of 4N (99.99% or more) was sealed in a rubber tube, subjected to isostatic pressing, and sintered at 1500 ° C. for 10 hours in the atmosphere.
  • a single crystal was grown using an optical FZ apparatus to obtain a ⁇ -Ga 2 O 3 single crystal.
  • the (100) plane of the obtained ⁇ -Ga 2 O 3 single crystal was cut out and polished by CMP to obtain a wafer-like substrate.
  • the substrate size is approximately 8 mm ⁇ 8 mm.
  • Electrodes were formed on the front and back of the ⁇ -Ga 2 O 3 single crystal by the processes of S1 to S7 described above, and a photodetector was manufactured. Each electrode arrangement is as shown in FIG.
  • the Schottky electrode on the surface of the ⁇ -Ga 2 O 3 single crystal has a diameter of 4 mm and is made of a deposited film of Au (film thickness 8 nm) / Ni (film thickness 2 nm).
  • the ohmic electrode on the back surface of the ⁇ -Ga 2 O 3 single crystal is disposed at a position corresponding to the Schottky electrode, and has a diameter of 4 mm and is formed of a deposited film of Au (film thickness 100 nm) / Ni (film thickness 50 nm).
  • the pad electrode is disposed in the center of the Schottky electrode, and has a diameter of 1 mm and is formed of a vapor deposition film of Au (film thickness: 100 nm) / Ni (film thickness: 5 nm).
  • a power source (voltage Vs) and a resistor (resistor R) were connected in series between the electrodes of the photodetector.
  • Vs voltage
  • resistor R resistor
  • Vs is the voltage of the power supply
  • the resistance value of R is the resistor
  • V R is the voltage between the terminals of the resistor
  • I pd is electromotive current
  • FIG. 1 ultraviolet rays were incident on the photodetector through an optical fiber cable.
  • the output end of an optical fiber cable having a core diameter of 400 ⁇ m is coupled to a Schottky electrode of a photodetector, and the wavelength from an ultraviolet lamp (ultraviolet generator SLUV-6 manufactured by ASONE Corporation) is directed toward the incident end of the optical fiber cable.
  • UV light of 254 nm was continuously irradiated.
  • the distance between the light receiving portion of the optical fiber cable and the ultraviolet lamp is 20 cm as described above.
  • FIG. 9 the measurement result of the sensitivity and irradiation power of the ultraviolet sensor of a present Example is shown.
  • FIG. 9 the measurement result of the sensitivity and irradiation power of the ultraviolet sensor of a present Example is shown.
  • FIG. 10 shows the measurement results of the electromotive current and irradiation power of the photodetector. From FIG. 9 and FIG. 10, the sensitivity of the ultraviolet sensor of this example and the electromotive current of the photodetector showed dependency on the ultraviolet irradiation power. Moreover, the sensitivity was comparable (several A / W) to that shown in Table 1 without the optical fiber cable.
  • FIG. 11 shows the measurement result of dark current. From FIG. 10 and FIG. 11, it was confirmed that the dark current was sufficiently small relative to the electromotive current and did not affect the measurement of the ultraviolet power.
  • UV emitting tool 1 UV sensor 2 Photo detector 3 Optical fiber cable 4 Light receiving part 10 ⁇ -Ga 2 O 3 single crystal 11 Schottky electrode 12 Ohmic electrode 13 Pad electrode

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  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Electromagnetism (AREA)
  • Power Engineering (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Light Receiving Elements (AREA)
  • Photometry And Measurement Of Optical Pulse Characteristics (AREA)
  • Lasers (AREA)
  • Optical Couplings Of Light Guides (AREA)

Abstract

La présente invention a trait à un capteur de rayonnement ultraviolet comprenant un photodétecteur destiné à détecter tout rayonnement ultraviolet et un ou plusieurs câbles à fibre optique permettant de transmettre le rayonnement ultraviolet au photodétecteur. Chaque câble à fibre optique est équipé d’une partie de réception de rayonnement destinée à recevoir le rayonnement ultraviolet et le photodétecteur comprend un cristal β-Ga2O3 et des électrodes respectivement formées sur la surface avant et la surface arrière du cristal β-Ga2O3.
PCT/JP2009/061614 2008-06-26 2009-06-25 Capteur de rayonnement ultraviolet WO2009157512A1 (fr)

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WO2011105251A1 (fr) * 2010-02-24 2011-09-01 日本軽金属株式会社 Détecteur d'ultraviolets et procédé de fabrication associé
CN102455213A (zh) * 2010-10-30 2012-05-16 比亚迪股份有限公司 光照传感器及雨量传感器
JP2013227160A (ja) * 2012-04-24 2013-11-07 Namiki Precision Jewel Co Ltd 酸化ガリウム単結晶、及び、酸化ガリウム単結晶基板
CN107515365A (zh) * 2017-06-29 2017-12-26 成都旭光光电技术有限责任公司 一种紫外光敏管的配对方法及设备
US20180374980A1 (en) * 2016-12-08 2018-12-27 Xidian University METHOD FOR MANUFACTURING ULTRAVIOLET PHOTODETECTOR BASED ON Ga2O3 MATERIAL
CN111477699A (zh) * 2020-04-16 2020-07-31 杭州紫芯光电有限公司 基于α-Ga2O3/TiO2异质结的日盲紫外探测器及其制备方法

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KR20230174446A (ko) * 2022-06-21 2023-12-28 아주대학교산학협력단 변전 효과를 이용한 광센서 및 이를 구비하는 바이오 진단 장치

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Publication number Priority date Publication date Assignee Title
WO2011105251A1 (fr) * 2010-02-24 2011-09-01 日本軽金属株式会社 Détecteur d'ultraviolets et procédé de fabrication associé
CN102455213A (zh) * 2010-10-30 2012-05-16 比亚迪股份有限公司 光照传感器及雨量传感器
JP2013227160A (ja) * 2012-04-24 2013-11-07 Namiki Precision Jewel Co Ltd 酸化ガリウム単結晶、及び、酸化ガリウム単結晶基板
US20180374980A1 (en) * 2016-12-08 2018-12-27 Xidian University METHOD FOR MANUFACTURING ULTRAVIOLET PHOTODETECTOR BASED ON Ga2O3 MATERIAL
US10629766B2 (en) * 2016-12-08 2020-04-21 Xidian University Method for manufacturing ultraviolet photodetector based on Ga2O3 material
CN107515365A (zh) * 2017-06-29 2017-12-26 成都旭光光电技术有限责任公司 一种紫外光敏管的配对方法及设备
CN107515365B (zh) * 2017-06-29 2019-12-13 成都旭光光电技术有限责任公司 一种紫外光敏管的配对方法及设备
CN111477699A (zh) * 2020-04-16 2020-07-31 杭州紫芯光电有限公司 基于α-Ga2O3/TiO2异质结的日盲紫外探测器及其制备方法
CN111477699B (zh) * 2020-04-16 2022-03-29 杭州紫芯光电有限公司 基于α-Ga2O3/TiO2异质结的日盲紫外探测器及其制备方法

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