JP5493100B2 - Discharge lamp - Google Patents

Description

  The present invention relates to a discharge lamp in which a rare gas is enclosed in a discharge tube and discharges light in the ultraviolet region.

  Ultraviolet rays are widely used in various industrial fields such as fluorescent lamps, photolithography light sources, sterilization treatment, UV curing, ozone generation, and mercury lamps are generally used as ultraviolet radiation lamps. Mercury and a rare gas are enclosed in a discharge vessel, and a voltage is applied between electrodes provided at both ends of the discharge tube, whereby discharge light emission due to mercury occurs, and ultraviolet light having a wavelength of 254 nm, 185 nm, or the like is emitted.

  In a mercury lamp, the ultraviolet radiation characteristics are likely to change due to changes in ambient temperature, and it is difficult to stabilize the required ultraviolet light output with high accuracy. Also, from the viewpoint of environmental problems, it is not desirable to continue to use harmful mercury in the future.

  As an ultraviolet light discharge lamp that does not use mercury, a discharge lamp in which carbon monoxide (CO) is sealed as a discharge gas has been proposed (see Patent Document 1 and Patent Document 2). In this method, carbon monoxide is enclosed in a discharge tube as a discharge gas by utilizing the strong ultraviolet rays emitted by the discharge plasma of carbon monoxide. During discharge, ultraviolet light is obtained from an ultraviolet region of 200 nm to 400 nm by carbon monoxide molecules and carbon monoxide ions.

Further, a deuterium lamp is known as a discharge lamp that can obtain a continuous spectrum in the vacuum ultraviolet to ultraviolet region instead of an emission line spectrum of a specific wavelength as in the above-described discharge lamp (see, for example, Patent Document 3). In the deuterium lamp, deuterium or a mixed gas of deuterium and hydrogen is enclosed in a discharge tube as a discharge gas.
JP 2004-111301 A JP 2002-358924 A JP 2007-335130 A

  The discharge lamps described in Patent Documents 1 and 2 cannot obtain high-intensity vacuum ultraviolet light. On the other hand, deuterium lamps are not configured to emit continuous ultraviolet light in the vacuum ultraviolet region and emit vacuum ultraviolet light of a specific wavelength at high output.

  The discharge lamp of the present invention is a lamp that emits ultraviolet light having a specific wavelength in the vacuum ultraviolet region at a high output, and a single carbon or a carbon compound is placed in a discharge tube in which neon gas (Ne) is sealed as a discharge gas. . Then, the emission is characterized in that emission of emission light is caused by carbon atoms (excitation thereof) as a light emission source in the vicinity of 156 nm in the vacuum ultraviolet region by a discharge mainly composed of neon gas.

  Here, “carbon alone or a carbon compound is included” means that carbon exists in various bonded states and phase states so that carbon atoms are present in the discharge tube at the time of discharge. This includes mixing a gas (hereinafter referred to as carbon-containing gas) with neon gas, mixing a liquid component containing carbon, or pre-depositing solid carbon in a discharge tube.

  In the discharge lamp of the present invention, a very strong emission line emission spectrum that cannot be obtained by a conventional discharge lamp is obtained in the vicinity of 156 nm in the vacuum ultraviolet region. This ultraviolet light is generated when carbon atoms are excited in a discharge plasma of neon gas. By mixing carbon in a discharge tube filled with neon gas, emission of light in the vacuum ultraviolet region, which was not possible with conventional discharge lamps, has been achieved.

  In the discharge lamp of one embodiment, the emission of the emission line near 156 nm is a peak emission in the wavelength range of 150 nm to 1800 nm, that is, in the vacuum ultraviolet region. That is, light around 156 nm is strongest in the vacuum ultraviolet region. Further, high-power ultraviolet light can be obtained even in the vicinity of 165 nm.

  Even if only neon gas is enclosed in the discharge tube, similar high-power emission line emission cannot be obtained in the vacuum ultraviolet region, and if emission gas other than neon gas is used as discharge gas, similar emission line emission can be obtained. I can't. The discharge lamp of the present invention achieves high output of vacuum ultraviolet light that could not be realized with conventional discharge lamps.

  The discharge lamp may be configured as a light source that directly uses ultraviolet rays, such as sterilization and photolithography, or may be configured as an illumination lamp that excites phosphors with vacuum ultraviolet light and emits visible light to the outside.

  The type of discharge lamp and the discharge method are not particularly limited, but in order to prevent carbon from adhering to the electrode, an electrodeless discharge lamp in which no electrode is disposed in the discharge space is preferable. For example, it may be configured as a microwave discharge lamp. What is necessary is just to set the enclosure pressure of discharge gas which has neon gas as a main component to about 10 kPa or more at about normal temperature, for example, what is necessary is just to set an enclosure pressure to atmospheric pressure.

In order to adjust the amount of carbon mixed in the discharge tube, a carbon-containing gas is preferably sealed in the discharge tube together with neon gas. The carbon-containing gas to be mixed may be a molecular gas containing carbon, for example, any gas of carbon monoxide (CO), carbon dioxide (CO ₂ ), methane (CH ₄ ), or a mixed gas thereof. If it is. With the discharge gas in which such a carbon-containing gas is added to the neon gas, bright line emission in the vacuum ultraviolet region can be obtained from the carbon atoms.

  As for the degree of carbon mixing, carbon may be mixed in a range that does not prevent the vacuum ultraviolet light from being emitted at a high output. In order to obtain as high output vacuum ultraviolet light as possible, a small amount of carbon-containing gas may be enclosed in the discharge tube, and the gas concentration N (%) of the carbon-containing gas with respect to neon gas is in the range of 0 <N ≦ 5.0. It is desirable to be in Further, the gas concentration N (%) is more desirably in the range of 0 <N ≦ 0.5, and most desirably in the range of 0 <N ≦ 0.2.

  In order to stably obtain high-output vacuum ultraviolet light, it is desirable that atoms and molecules other than carbon atoms such as oxygen are not mixed in the discharge tube. Therefore, it is desirable that solid carbon is mixed in the discharge tube in advance to excite carbon atoms in the discharge plasma of neon gas.

  In order to facilitate the excitation of carbon atoms throughout the discharge tube, it is preferable that a carbon film is attached in advance to the inner wall of the discharge tube. Alternatively, in order to simplify the preparation for carbon mixing, carbon pieces may be mixed in the discharge tube in advance. The mixing amount of carbon may be determined in a range that does not hinder the high output of vacuum ultraviolet light.

  A method for manufacturing a discharge lamp according to the present invention is a method for manufacturing a discharge lamp in which a mixed gas of neon gas and carbon-containing gas is enclosed in a discharge tube, wherein the sealed pressure of the mixed gas is set to 10 kPa or more, and The gas concentration N (%) is defined in a range of 0 <N ≦ 5.0. Alternatively, as a method of manufacturing a discharge lamp in which solid carbon is mixed, neon gas is sealed as a discharge gas after a carbon film is attached to the inner wall of the discharge tube, and the sealing pressure of the neon gas is set to 10 kPa or more.

  In the discharge light emission method of the present invention, a carbon simple substance or a carbon compound is mixed in a discharge tube in which neon gas (Ne) is sealed as a discharge gas, and vacuum ultraviolet light around 156 nm originating from carbon atoms is emitted by discharge. It is characterized by. By emitting discharge light in a discharge tube containing carbon and neon gas, it can be used for a process requiring vacuum ultraviolet light such as a sterilization process.

  ADVANTAGE OF THE INVENTION According to this invention, the discharge lamp which can radiate | emit the vacuum ultraviolet light of a specific wavelength with high output can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a micro discharge lamp according to the first embodiment.

  A microwave discharge lamp 10 configured as a light source device is a discharge lamp in which a quartz discharge tube 12 is inserted into a hollow portion of a discharge microwave cavity (resonator) 20 and is discharged by supplying microwave power. Emits light. The open end 12 </ b> A of the discharge tube 12 is accommodated in the chamber 15 and sealed by an O-ring 17.

The chamber 15 has a tubular portion 15 </ b> A extending in the axial direction of the discharge tube 12, and the tubular portion 15 </ b> A communicates with the vacuum pump 40 and the gas tanks 42 and 44 via the gas conduit 50. A vacuum flange portion 19 provided with an MgF ₂ window 14 is connected to the end portion of the tubular portion 15A, and light from the discharge light is emitted through the MgF ₂ window 14 to the outside of the discharge tube. A vacuum ultraviolet spectrometer (not shown) or a vacuum container (not shown) containing an irradiation object can be attached to the MgF ₂ window 14.

  Carbon monoxide gas (CO) and neon gas (Ne) are sealed in the gas tanks 42 and 44, respectively, and a low pressure vacuum gauge (pressure gauge) 62 and a high pressure vacuum gauge 64 are connected to the gas conduit 50. Yes. Ne and CO gas are supplied to the discharge tube 12 by opening and closing the valves 52, 54, 55, 57 and 59.

  In the discharge tube 12, a mixed gas of CO in Ne is sealed as a discharge gas, and the gas supply is adjusted so that the CO gas concentration N (%) with respect to Ne becomes 5% or less. Further, the discharge gas sealing pressure (Pa) is adjusted to 100 kPa which is substantially the same as the atmospheric pressure.

  A coaxial output type microwave oscillator 22 connected to a power supply unit (not shown) supplies microwave power to the microwave cavity 20 via a coaxial cable 24. In the microwave cavity 20, a microwave electric field is applied in the cavity by microwave power. As a result, the discharge gas in the discharge tube 12 enters a plasma state and discharges light.

In discharge light emission, vacuum ultraviolet light having a specific wavelength resulting from excitation of carbon atoms (C) is emitted to the outside through the MgF ₂ window 14 together with light emission by Ne. Vacuum ultraviolet light is used for photoexcitation processes such as substrate surface treatment.

  FIG. 2 is a diagram showing an emission spectrum in the vacuum ultraviolet region observed by attaching the vacuum ultraviolet spectrometer to the discharge lamp 10. However, the sealing pressure of the discharge gas is 100 kPa, the gas concentration N is 0.5%, and the microwave power is 60 W.

  As shown in FIG. 2, when the discharge lamp 10 is made to emit light, a very strong emission line spectrum SP1 is obtained in the vicinity of a wavelength of 156 nm. Further, a strong emission line spectrum SP2 is obtained even in the vicinity of 165 nm. In the vacuum ultraviolet region, the bright line spectrum SP1 near the wavelength of 156 nm has the highest relative intensity, and the discharge lamp 10 emits a peak at around 156 nm. The relative intensity of the bright line spectrum SP2 near the wavelength of 165 nm is the next highest.

  This very strong spectrum near 156 nm is attributed to the carbon atom (C). The CO enclosed in the discharge tube 12 is decomposed during Ne plasma discharge to generate carbon atoms. The generated carbon atoms are excited by the microwave plasma and emit bright lines near a wavelength of 156 nm. The same applies to the emission of emission lines near the wavelength of 165 nm.

Since O and O ₂ generated by the decomposition of CO become an obstacle to vacuum ultraviolet light, the light output can be increased as the amount of mixed CO gas is smaller. FIG. 2 shows an emission spectrum when the gas concentration N is 0.5%, but by further reducing the gas concentration N, higher-power vacuum ultraviolet light can be obtained.

  As described above, in this embodiment, in the microwave discharge lamp 10 in which Ne gas is sealed in the discharge tube as the discharge gas, a small amount of CO gas (gas concentration N is 5% or less) is added to the Ne gas, and the microwave power is reduced. Discharge light emission by supplying. At this time, high-intensity emission line spectra are obtained at 156 nm and 165 nm.

  Since stable high-output spectral light is obtained in the vacuum ultraviolet region, it can be used as a light source device for exposure processing, sterilization processing, UV curing processing and the like that require high-power spectral light in a narrow band. Further, except for the discharge gas sealed in the discharge tube, it is the same as the conventional microwave discharge lamp, and high-power vacuum ultraviolet light can be obtained without changing the lamp structure.

  As described above, the higher the emission spectrum is obtained as the gas concentration N of the mixed CO gas is lowered, it is preferable to reduce the gas concentration N (%) as much as possible. For example, the gas concentration N is preferably 0.2% or less. However, the gas concentration N may be determined within a range in which a spectrum having an intensity higher than that required for the discharge lamp 10 in the usage environment is obtained. If the gas concentration is set to 5% or less, a sufficient output spectrum can be obtained. Alternatively, a gas concentration N exceeding 5% may be set.

  The charging pressure of the discharge gas may be determined within a range in which a spectrum having a required intensity can be obtained, and may be equal to or lower than atmospheric pressure or equal to or higher than atmospheric pressure, for example, 10 kPa or higher.

In this embodiment, a small amount of CO gas is added to Ne gas, but other molecular gases containing carbon atoms (CO ₂ , CH _4, etc. are referred to as carbon-containing gas here) may be mixed. Very strong emission line spectra are similarly obtained at around 156 nm and 165 nm. When a molecular gas containing oxygen such as CO or CO ₂ is mixed, a getter material is disposed so as to absorb oxygen generated during discharge, for example, by coating a film such as Al or Ti on the inner wall of the discharge tube in advance. It is good.

  Next, the microwave discharge lamp which is 2nd Embodiment is demonstrated using FIG. In the second embodiment, one end of the discharge tube is cut off without being connected to a vacuum pump.

  FIG. 3 is a schematic configuration diagram of a microwave discharge lamp according to the second embodiment.

One end of the discharge tube 120 in the microwave discharge lamp 100 is cut off, and an MgF ₂ window 124 is attached to one end of the discharge tube 120 with a vacuum-tight adhesive (toll seal). A joint glass 122 is provided between the main body portion 120A of the quartz discharge tube 120 and the MgF ₂ window 124 in order to prevent distortion due to a difference in thermal expansion coefficient between the MgF ₂ window 124 and the discharge tube main body portion 120A. Yes.

  A carbon thin film is attached to the inner wall of the discharge tube 120, and before the discharge tube 120 is sealed off, a carbon thin film is attached by mixing with a gas such as CO before discharging light, and then a vacuum is drawn. Cut off the seal. When microwave power is supplied from the microwave oscillator 22, a microwave electric field is applied, and discharge light is emitted. During the plasma discharge of the neon gas, the carbon atoms attached to the inner wall of the discharge tube 120 are excited and a very strong emission line spectrum is obtained at around 156 nm and 165 nm.

In the second embodiment, since a carbon thin film, that is, solid carbon is mixed in the discharge tube 120, there is no obstacle to discharge light emission due to other molecules such as O and O ₂ generated when encapsulating the carbon thin film. As a result, the emission spectra in the vicinity of 156 nm and 165 nm have a high output equivalent to or higher than that of the first embodiment, and a discharge lamp having excellent luminous efficiency can be obtained.

  In addition, you may comprise so that a carbon piece may be previously provided in the discharge tube 120 instead of making a carbon thin film adhere. Further, in the first and second embodiments, the carbon-containing gas and solid carbon are mixed, but carbon simple substance or carbon compound containing carbon atoms with oil, organic solvent, plastic piece or the like is contained in the discharge tube 12. You may comprise so that it may mix.

  In the microwave discharge lamps of the first and second embodiments, ultraviolet light is radiated to the outside, but a phosphor may be attached to the inner wall of the discharge tube 12 to radiate visible light to the outside. Further, a microwave discharge lamp other than the type described above may be configured, and a microwave discharge lamp using a three-dimensional circuit element, a waveguide, or the like may be applied.

  Furthermore, it is also possible to apply a discharge method other than microwave discharge, which may be discharge by high frequency discharge, alternating current, direct current discharge, electrodeless discharge lamp other than microwave discharge lamp, internal electrode type The present invention can also be applied to various types of discharge lamps such as a discharge lamp.

  Below, based on the Example according to the microwave discharge lamp in 1st Embodiment, a spectral characteristic, ie, high output bright line light emission in a vacuum ultraviolet region, is demonstrated.

  FIG. 4 is a diagram comparing the emission spectrum of the microwave discharge lamp in Example 1 with the emission spectrum of the deuterium discharge lamp.

  The microwave discharge lamp of Example 1 is configured to use the same microwave cavity as that of the first embodiment, and a coaxial output type microwave oscillator is connected to a microwave cavity (MC-III manufactured by Nippon High Frequency Co., Ltd.) via a coaxial cable. ) Is connected. Moreover, the spectrum of the vacuum ultraviolet light was measured using the vacuum ultraviolet spectrometer (VM-504 by Acton Research) and the photomultiplier tube (DA-780-VUV by Acton Research).

A discharge glass tube with a length of 500 mm and a diameter of 15 mm and made of quartz glass is prepared. The discharge tube is connected to the chamber (gauge port adapter) and the MgF ₂ window material is coaxially coupled to the chamber. The incident port of the vacuum ultraviolet spectrometer was attached to the MgF ₂ window. In order to accurately measure the vacuum ultraviolet light, the vacuum ultraviolet spectrometer itself was evacuated to a high vacuum and a tube was attached to the vacuum flange to evacuate the remaining air. Further, high vacuum evacuation was performed between the MgF ₂ window and the entrance slit of the vacuum ultraviolet spectrometer, and the entrance port of the vacuum ultraviolet spectrometer was vacuum sealed with the MgF ₂ window.

  The procedure for charging the discharge gas will be described with reference to the reference numeral in FIG. 1. After the inside of the discharge tube was evacuated, the valve 52 was opened in a state where the low-pressure vacuum gauge could be used, and CO gas was supplied. Then, while adjusting the bulb 55, CO gas was sealed in the discharge tube until the low-pressure vacuum gauge display reached 1 kPa.

  After removing the CO gas remaining in the gas pipeline, the valve 54 was opened in a state where the high-pressure vacuum gauge could be used, and Ne gas was supplied. Then, while adjusting the bulb 55, Ne gas was sealed in the discharge tube until the display of the high-pressure vacuum gauge reached 100 kPa.

  The discharge tube inserted and fixed in the microwave cavity was discharged with a microwave power of 60 W and a microwave frequency of 2.45 GHz. An electron multiplier tube was installed at the emission port of the vacuum ultraviolet spectrometer, and the light intensity was measured by a voltage value (mV).

  On the other hand, as a deuterium lamp as a comparative example, a deuterium lamp (L10366 type) manufactured by Hamamatsu Photonics was prepared, and the vacuum ultraviolet spectrometer was connected to the light emission portion of the deuterium lamp. The distance between the light outlet of the deuterium lamp and the incident port of the vacuum ultraviolet spectrometer is set so that the distance between the discharge light emitting region of the discharge lamp and the incident port is the same distance. Then, the deuterium lamp was discharged with the same power of 60 W.

  In FIG. 4A, the relative spectral intensity on the vertical axis is defined according to the spectral intensity level of the microwave discharge lamp. The emission spectrum of the microwave discharge lamp in FIG. 4A corresponds to the emission spectrum shown in FIG. On the other hand, in FIG. 4B, the relative spectral intensity on the vertical axis is defined in accordance with the spectral intensity level of the deuterium lamp.

  As is clear from FIGS. 4A and 4B, it is confirmed that the microwave discharge lamp can obtain a strong spectrum of about 40 times or more around 156 nm and 165 nm. This indicates that it is very useful as a light source device that emits vacuum ultraviolet light having a specific wavelength.

FIG. 5 is a diagram showing an emission spectrum when the concentration of the mixed CO ₂ gas is changed in the microwave discharge lamp of Example 2. The gas concentration N of CO ₂ with respect to Ne was set to 0.2%, 0.5%, and 5%, and the emission spectrum was measured. The configuration of the microwave discharge lamp is the same as that of the first embodiment, and the experimental conditions other than the concentration of the enclosed gas are substantially the same as the conditions shown in the first embodiment.

As shown in FIG. 5, it is confirmed that the lower the CO ₂ gas concentration N, the higher the spectral intensities at wavelengths of 156 nm and 165 nm. Although not shown here, the spectrum intensity when the gas concentration N of CO ₂ is 1.0% is between the gas concentration of 0.5% and the gas concentration of 5.0%, and the gas concentration of 0.7%. % Spectral intensity is between 0.5% gas concentration and 1.0% gas concentration. This is the same except for the CO ₂ gas. In the gas concentration range of 0.2% to 5%, the lower the gas concentration of CO, CH ₄ or the like, the higher the spectral intensity.

FIG. 6 is a diagram showing a spectral distribution when the carbon-containing gas added to neon is changed in the microwave discharge lamp of Example 3. However, the spectrum at a predetermined time from the start of discharge is shown. The discharge lamp with a gas concentration of 0.2% for CO, CO ₂ , and CH ₄ with respect to Ne was mixed, and the spectral distribution of the discharge lamp with a discharge gas sealing pressure of 100 kPa was measured. The configuration and discharge conditions of the microwave discharge lamp are substantially the same as those in Example 1 except for the type of discharge gas to be sealed and the gas concentration.

As shown in FIG. 6, it is confirmed that the emission line spectrum having the highest intensity is obtained at about 156 nm in any of CO, CO ₂ and CH ₄ gases. Then, it is confirmed that bright line emission with the next highest spectral intensity is obtained in the vicinity of 165 nm.

FIG. 7 is a diagram showing the time course of the spectral intensity of 156 nm of three discharge lamps each containing CO, CO ₂ , and CH ₄ as mixed gases in the microwave discharge lamp of Example 4. FIG. 8 is a graph showing the time course of the spectral intensity of 165 nm in the microwave discharge lamp of Example 4. The configuration and discharge conditions of the microwave discharge lamp are substantially the same as those of the first embodiment except for the type of discharge gas to be sealed and the gas concentration.

The gas concentration N with respect to Ne was set at 0.2%, and the time course of spectral intensities of 156 nm and 165 nm was measured for a discharge lamp mixed with CO, CO ₂ and CH ₄ , respectively. The spectrum intensity changes to some extent until 12 minutes have elapsed from the start of discharge, the spectrum intensity starts to converge after 15 to 20 minutes, and the spectrum intensity is almost stabilized after 30 minutes.

  As is clear from FIGS. 7 and 8, it is confirmed that when the discharge emission becomes stable, the high-output emission line emission near wavelengths of 156 nm and 165 nm is maintained as it is. That is, it is confirmed that stable and high-power vacuum ultraviolet light can be obtained even when used as a discharge lamp for a long time.

  FIG. 9 is a diagram showing the spectral distribution in the vacuum ultraviolet region in the microwave discharge lamp of Example 5 in which a carbon thin film was previously attached to the inner wall of the discharge tube. Regarding the configuration and discharge conditions of the microwave discharge lamp, the microwave power is 50 W, the carbon thin film is adhered in the discharge tube, and pure neon gas is sealed instead of sealing the mixed gas with the carbon-containing gas. Except this, it is the same as the first embodiment.

  As is clear from FIG. 9, high-output emission line spectra are obtained at about 156 nm and 165 nm. This indicates that a similar spectrum can be obtained by mixing carbon as a solid in the discharge tube instead of mixing the carbon-containing gas.

  FIG. 10 is a diagram showing an emission spectrum when a rare gas other than neon gas is sealed in the microwave discharge lamp of Example 6. The configuration of the microwave discharge lamp and the discharge conditions are substantially the same as those in Example 5 except for the discharge conditions other than the rare gas to be enclosed.

  As shown in FIG. 10, a similar emission spectrum cannot be obtained using rare gases other than neon, xenon (Xe), krypton (Kr), argon (Ar), and helium (He) as discharge gases. Further, even when a small amount of CO gas was added, an emission spectrum similar to that when pure Ne gas was sealed could not be obtained. From this, it was confirmed that a very strong emission line emission was obtained in the vacuum ultraviolet region for the first time by a combination of Ne and carbon.

It is a typical block diagram of the micro discharge lamp which is 1st Embodiment. It is the figure which showed the emission spectrum of the vacuum ultraviolet region observed by attaching a vacuum ultraviolet spectrometer to a discharge lamp. It is a typical block diagram of the microwave discharge lamp which is 2nd Embodiment. In the microwave discharge lamp of Example 1, it is the figure which compared the emission spectrum of the microwave discharge lamp, and the emission spectrum of the deuterium discharge lamp. In the microwave discharge lamp of Example 2 is a diagram showing an emission spectrum when varying concentrations of contaminating CO ₂ gas. In the microwave discharge lamp of Example 3, it is the figure which showed the spectrum distribution when changing the carbon containing gas added with respect to neon. In the microwave discharge lamp of Example 4 is a diagram showing the time course of the spectral intensity of 156nm of the three discharge lamps CO as a gas to be mixed, CO _2, CH ₄ were sealed, respectively. In the microwave discharge lamp of Example 5, it is the figure which showed the time passage of the spectrum intensity of 165 nm. In the microwave discharge lamp of Example 5, it is the figure which showed the spectrum distribution of the vacuum ultraviolet region in the microwave discharge lamp which made the carbon thin film adhere to the discharge tube inner wall. In the microwave discharge lamp of Example 6, it is the figure which showed the emission spectrum when noble gases other than Ne were enclosed.

Explanation of symbols

10, 100 Microwave discharge lamp 12, 120 Discharge tube 20 Microwave cavity 40 Vacuum pump

Claims (16)

As the discharge gas, a mixed gas of neon gas (Ne) and carbon-containing gas is enclosed in the discharge tube,
The discharge pressure of the discharge gas is 100 kPa or more,
The gas volume concentration N (%) of the carbon-containing gas with respect to the neon gas is in the range of 0 <N ≦ 5.0,
A discharge lamp characterized in that emission of bright lines occurs when a carbon atom (C) is excited in the vicinity of 156 nm in a vacuum ultraviolet region by a discharge mainly composed of neon gas.   The discharge lamp according to claim 1, wherein the relative spectral intensity of emission line emission in the vicinity of 156 nm is the highest in the vacuum ultraviolet region.   3. The discharge lamp according to claim 2, wherein a bright line is emitted when the carbon atom (C) is excited in the vicinity of 165 nm in the vacuum ultraviolet region.   4. The discharge lamp according to claim 3, wherein the relative spectral intensity of emission line emission in the vicinity of 165 nm is next to the relative spectral intensity of emission line emission in the vicinity of 156 nm in the vacuum ultraviolet region. The discharge lamp according to claim 4, wherein the carbon-containing gas contains at least one of carbon monoxide (CO), carbon dioxide (CO ₂ ), and methane (CH ₄ ).   The discharge lamp according to claim 5, wherein the carbon-containing gas is carbon monoxide.   2. The discharge lamp according to claim 1, wherein the gas capacity concentration N (%) is in a range of 0 <N ≦ 0.5.   8. The discharge lamp according to claim 7, wherein the gas capacity concentration N (%) is in a range of 0 <N ≦ 0.2. Solid carbon is put in a discharge tube filled with neon gas (Ne) as a discharge gas,
Neon gas sealing pressure is 100 kPa or more,
A discharge lamp characterized in that emission of bright lines occurs when a carbon atom (C) is excited in the vicinity of 156 nm in a vacuum ultraviolet region by a plasma discharge of neon gas.   The discharge lamp according to claim 9, wherein the carbon film is attached to the inner wall of the discharge tube.   The discharge lamp according to claim 9, wherein carbon pieces are mixed in the discharge tube.   The discharge lamp according to claim 1, wherein the discharge lamp is an electrodeless discharge lamp.   The discharge lamp according to claim 1, wherein the discharge lamp is a microwave discharge lamp.   The discharge lamp according to any one of claims 1 to 13, wherein an enclosure pressure of the discharge gas is set to atmospheric pressure. A method for manufacturing a discharge lamp, comprising:
Enclose a mixture of neon gas and carbon-containing gas in the discharge tube,
The sealing pressure of the mixed gas is set to 100 kPa or more,
A method for manufacturing a discharge lamp, characterized in that a gas capacity concentration N (%) of a carbon-containing gas with respect to a neon gas is set in a range of 0 <N ≦ 5.0. A method for manufacturing a discharge lamp, comprising:
Neon gas is sealed as a discharge gas in a discharge tube with a carbon film attached to the inner wall,
A method for manufacturing a discharge lamp, wherein a sealing pressure of neon gas is set to 100 kPa or more.

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