JP4123845B2 - UV sensor and UV illuminance meter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to improvements in ultraviolet sensors and ultraviolet illuminance meters for measuring the amount of ultraviolet rays such as excimer lamps and low-pressure mercury lamps.
[0002]
[Prior art]
In recent years, powerful short-wavelength ultraviolet rays such as excimer lasers such as ArF (193 nm) and F ₂ (157 nm), a mercury lamp (185 nm) emitting light in the vacuum ultraviolet region, and a xenon excimer lamp (172 nm) have begun to be used industrially. Accordingly, there is a demand for an ultraviolet sensor that can measure a strong short wavelength ultraviolet ray with high accuracy and continuously for a long period of time in a harsh environment where moisture or gas is generated.
[0003]
Conventional sensors for measuring the intensity of short-wavelength ultraviolet light have versatility detection such as phototube detectors, gallium nitride photovoltaic detectors, silicon photodiodes (silicon photovoltaic detectors) that are sensitive only to specific wavelengths. A combination of a filter that transmits only a specific wavelength or a fluorescent plate that converts ultraviolet light into visible light has been used.
[0004]
In addition, for example, an ultraviolet sensor has a substrate disposed on the inner bottom of a cylindrical metal cap formed by supporting quartz glass on a light receiving window, and a light receiving element is disposed on the substrate, and the quartz glass, the metal cap, the substrate, and the light receiving element. In this case, an epoxy resin is used for bonding.
Further, for example, in Japanese Patent Application Laid-Open No. 11-248531, an ultraviolet light transmissive glass window and a metal cap are bonded by airtight fusion, a substrate and a light receiving element are bonded by a heat resistant adhesive, and a substrate and a metal cap are mechanically welded. It is practiced to join.
[0005]
[Problems to be solved by the invention]
However, under strong ultraviolet light, the decrease in ultraviolet light transmittance cannot be ignored even with quartz glass. In addition, when quartz glass is used, ultraviolet rays of 160 nm or less are not transmitted, and the ultraviolet rays of a 157 nm F ₂ laser and a 146 nm krypton excimer lamp cannot be measured even when a diamond sensor having a light receiving sensitivity range of 120 nm to 225 nm is used.
In addition, when an ultraviolet transmissive glass that can be directly hermetically fused with a metal is used, ultraviolet rays of 230 nm or less are not transmitted, and the measurement range is further limited.
[0006]
Furthermore, conventionally, for example, an organic adhesive is generally used to reduce the difference in expansion coefficient when the quartz glass and the metal cap are joined. However, when an organic adhesive is used, the organic substance is caused by ultraviolet rays or heat. Since the organic gas is further deteriorated, the operation of the light receiving element is unstable.
[0007]
The present invention has been invented in view of the above-mentioned points, and the measurement range of ultraviolet rays is widened, the joints do not change for a long time, and the amount of ultraviolet rays such as excimer lamps and low-pressure mercury lamps can be accurately measured for a long time. An object is to provide a possible ultraviolet sensor and ultraviolet illuminance meter.
[0008]
[Means for Solving the Problems]
The present invention has the following configuration in order to solve the above problems.
In an ultraviolet sensor in which an ultraviolet light receiving element is hermetically arranged in a metal cap having an inert gas atmosphere inside, an F ₂ (157 nm) or ArF (193 nm) excimer laser, vacuum ultraviolet light emission It is configured to be able to measure short wavelength ultraviolet rays emitted from a mercury lamp (185 nm), a xenon excimer lamp (172 nm), etc., and a metal substrate is disposed in the metal cap, and a short wavelength of 120 nm to 225 nm is provided on the metal substrate. A diamond thin film photoconductive light-receiving element that is sensitive only to ultraviolet light is attached and mounted, and the light receiving window of the metal cap has a short wavelength in this wavelength range so as to have detection sensitivity only for short-wave ultraviolet light of 140 nm to 225 nm. A sapphire plate that transmits ultraviolet light is bonded and the metal cap and metal substrate are joined by resistance welding. Alternatively, the metal substrate is composed of a gold-tin alloy metal, and the metal substrate and the sapphire plate are bonded using a molybdenum-manganese alloy metal hermetic seal or a low-melting glass junction. Bonding the photoconductive light-receiving element is characterized in that no organic material is used .
[0010]
According to a second aspect of the present invention , the adhesion between the metal substrate and the diamond thin film photoconductive light-receiving element is constituted by metal bonding using a gold-silicon alloy or a gold-germanium alloy.
[0012]
UV intensity meter according to claim 3, it is constituted by mounting an ultraviolet sensor according to claim 1 or claim 2, wherein.
[0013]
According to the ultraviolet sensor of claim 1, the measurement range of ultraviolet rays is widened, the joint can stably measure ultraviolet rays for a long time, and the ultraviolet illuminometer equipped with the ultraviolet sensor is accurate for a long time. In addition, the amount of ultraviolet rays such as excimer lamps and low-pressure mercury lamps can be measured.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to FIGS. 1 and 2 are diagrams showing an embodiment of the ultraviolet sensor of the present invention. FIG. 1 is a front view and FIG. 2 is a cross-sectional view. 1 and 2, reference numeral 1 denotes an ultraviolet resistant metal cap, which is made of, for example, an iron alloy in a cylindrical shape or a box shape. A metal substrate 2 is hermetically arranged at the bottom of the metal cap 1 and is formed of, for example, an iron alloy in a circular or square shape. Reference numeral 3 denotes a diamond thin film photoconductive light-receiving element which is bonded and mounted on the upper surface of the metal substrate 2. The diamond thin film photoconductive light-receiving element 3 is configured to be sensitive to short wavelength ultraviolet rays. Short wavelength ultraviolet rays are approximately 120 nm to 225 nm. Reference numeral 4 denotes a sapphire plate that is hermetically arranged in the light receiving window of the metal cap 1 and transmits short-wavelength ultraviolet rays. Short wavelength ultraviolet rays are approximately 140 nm to 225 nm. If quartz glass is used instead of the sapphire plate, the transmittance is reduced by irradiation with short wavelength ultraviolet rays. The internal space formed by the metal cap 1 and the metal substrate 2 formed by bonding and mounting the diamond thin film photoconductive light receiving element 3 on the upper surface is configured as an inert gas atmosphere. As the inert gas, for example, nitrogen gas or argon gas is used.
[0015]
The metal cap 1 and the metal substrate 2 are bonded together, the metal substrate 2 and the diamond thin film photoconductive light receiving element 3 are bonded, and the metal cap 1 and the sapphire plate 4 are bonded without using an organic material.
[0016]
The above-described joining of the metal cap 1 and the metal substrate 2 is configured by resistance welding or metal joining of a gold-tin alloy.
According to this bonding, after irradiating with a low-pressure mercury lamp for 500 hours, when the ultraviolet intensity of the low-pressure mercury lamp was measured again under humid conditions, the indicated value was not different from that before irradiation and was stable. .
Here, when an experiment was performed under the same conditions using an epoxy resin adhesive widely used for bonding semiconductors, it was confirmed that the indicated value may be large or small and unstable.
[0017]
The adhesion between the metal substrate 2 and the diamond thin film photoconductive light-receiving element 3 is constituted by metal bonding using a gold-silicon alloy or a gold-germanium alloy.
According to this bonding, after irradiating with a low-pressure mercury lamp for 500 hours, when the UV intensity of the low-pressure mercury lamp was measured again under high humidity conditions, the indicated value was irradiated as in the case of the metal cap 1 and the metal substrate 2. There was no difference and it was stable.
In the adhesion between the metal substrate 2 and the diamond thin film photoconductive light-receiving element 3, when an experiment is performed under the same conditions using an epoxy resin adhesive widely used for semiconductor adhesion, the indicated value decreases as the value increases. In some cases, it was confirmed to be unstable.
[0018]
The metal cap 1 and the sapphire plate 4 are bonded by using a molybdenum-manganese alloy metal hermetic seal or a low melting point glass bonding.
According to this bonding, after irradiating with a low-pressure mercury lamp for 500 hours, when the ultraviolet intensity of the low-pressure mercury lamp was measured again under high humidity conditions, the metal cap 1 and metal substrate 2 case, metal substrate 2 and diamond As in the case of the thin-film photoconductive light-receiving element 3, the indicated value was not different from that before irradiation and was stable.
In this case, even when a joining with a low melting point glass was used instead of the metal hermetic seal of the molybdenum-manganese alloy, the indicated value was not different from that before irradiation and was stable.
Here, when an experiment was performed under the same conditions using an epoxy resin adhesive widely used for bonding semiconductors, it was confirmed that the indicated value may be large or small and unstable.
[0019]
Reference numeral 5 denotes a pair of lead terminals for obtaining a signal from the diamond thin film photoconductive light-receiving element 3, which is configured to penetrate the metal substrate 2. Reference numeral 6 denotes a lead wire, which is configured by connecting the diamond thin film photoconductive light-receiving element 3 and the lead terminal 5.
[0020]
Further, as described above, when the diamond thin film photoconductive light receiving element is housed in a sealed container and the inside thereof is an inert gas atmosphere, the diamond thin film photoconductive light receiving element does not come into contact with moisture, gas, and dust. The amount of ultraviolet rays can be measured for a long time without being affected by the measurement atmosphere. Moreover, since the sapphire plate is closely arranged in the light receiving window of the metal cap 1, short wavelength ultraviolet rays in the range of about 140 nm to 225 nm are accurately transmitted.
[0021]
Next, experimental examples of the ultraviolet sensor according to the present invention will be described.
First, when a xenon excimer lamp is turned on using quartz glass for the light receiving window of the metal cap 1 having the above-described configuration, the transmittance of ultraviolet rays is reduced by 20% after 360 hours of lighting. On the other hand, when a xenon excimer lamp was similarly turned on using a sapphire plate for the light receiving window of the metal cap 1, it was confirmed that there was no change in the transmittance of ultraviolet rays after 360 hours of lighting.
[0022]
Next, an ultraviolet illuminometer equipped with the above-described ultraviolet sensor will be described with reference to FIG. In FIG. 3, reference numeral 10 denotes an ultraviolet illuminance meter light receiving unit on which the ultraviolet sensor according to any one of claims 1 to 4 is mounted, 11 denotes an ultraviolet illuminance meter body, 12 denotes an ultraviolet illuminance meter light receiving unit 10 and an ultraviolet illuminance meter body 11. The connection cable 13 formed by connecting is a display, for example, digitally displayed. 14 is a power switch formed on the constituent wall of the ultraviolet illuminance meter main body 11, and 15 is an external output terminal.
According to the ultraviolet illuminance meter shown in FIG. 3, since the light receiving portion has an airtight structure, the light receiving element does not touch moisture, gas, and dust, the indicated value is stable, and the light receiving portion transmits short wavelength ultraviolet light. Since sapphire is used, there is little decrease in transmittance due to ultraviolet rays. Furthermore, there are organic bonding methods for bonding metal caps and metal substrates, bonding metal substrates and diamond thin film photoconductive light-receiving elements, and bonding metal caps and sapphire plates. Since no material is used, the junction does not change for a long time, and the amount of ultraviolet light from an excimer lamp, a low-pressure mercury lamp, or the like can be accurately measured for a long time.
[0023]
【The invention's effect】
The ultraviolet sensor according to claim 1 and claim 2 has a wide ultraviolet ray measurement range, a small decrease in transmittance due to ultraviolet rays, and since no organic material is used, the inside of the ultraviolet sensor does not deteriorate and decompose, There is a special effect that can be measured stably without changing the joint for a long time.
[0024]
The ultraviolet illuminance meter according to claim 3 has a special effect capable of measuring the amount of ultraviolet rays of a wide range of excimer lamps, low-pressure mercury lamps and the like.
[Brief description of the drawings]
FIG. 1 is a front view of an ultraviolet sensor according to the present invention.
FIG. 2 is a cross-sectional view of the ultraviolet sensor of FIG.
FIG. 3 is a front view of an ultraviolet illuminance meter according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Metal cap 2 Metal substrate 3 Diamond thin film photoconductive type light receiving element 4 Sapphire plate 5 Lead terminal 6 Lead wire 10 UV illuminance meter light-receiving part 11 UV illuminance meter main body 12 Connection cable 13 Display part 14 Power switch 15 External output terminal

Claims (3)

In an ultraviolet sensor in which an ultraviolet light receiving element is hermetically arranged in a metal cap that has an inert gas atmosphere inside,
F ₂ (157 nm) or ArF (193 nm) excimer laser, vacuum ultraviolet light emitting mercury lamp (185 nm), xenon excimer lamp (172 nm), etc.
A metal substrate is disposed in the metal cap, and a diamond thin film photoconductive light-receiving element having sensitivity only to short-wavelength ultraviolet rays of 120 nm to 225 nm is bonded and mounted on the metal substrate. A sapphire plate that transmits short-wavelength ultraviolet light in this wavelength range is bonded and disposed so as to have detection sensitivity only for short-wavelength ultraviolet light of 225 nm, and the metal cap and the metal substrate are bonded by resistance welding or a gold-tin alloy. The metal substrate and the sapphire plate are bonded using a molybdenum-manganese alloy metal hermetic seal or a low melting point glass bond, and the metal substrate and the diamond thin film photoconductive photo detector The UV sensor is characterized by not using an organic material. 2. The ultraviolet sensor according to claim 1, wherein the metal substrate and the diamond thin film photoconductive light-receiving element are bonded to each other by metal bonding using a gold-silicon alloy or a gold-germanium alloy.   An ultraviolet illuminance meter comprising the ultraviolet sensor according to claim 1 or 2 mounted thereon.

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