JPH11204087A - Light source apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source apparatus capable of stabilizing the quantity of ultraviolet rays emitted out of a window member of a lamp house within a short time. SOLUTION: This light source apparatus comprises a dielectric barrier discharge lamp 10 capable of emitting ultraviolet rays by producing excimer laser in a discharge container 11 by dielectric barrier discharge, a lamp house 20 housing the dielectric barrier discharge lamp 10 and a window member 25 for transmitting ultraviolet rays out of the dielectric barrier discharge lamp 10, and a photo sensor 40 for detecting the quantity of the ultraviolet rays out of the dielectric barrier discharge lamp 10. The electric power to be applied to the dielectric barrier discharge lamp 10 of this light source is so controlled by feed back control as to keep the quantity of the ultraviolet rays detected by the photo sensor 40 constant. The distance D1 from the outer surface of the discharge container 11 of the dielectric barrier discharge lamp 10 to the light receiving part 41 of the photo sensor 40 is controlled to be practically the same as the distance D2 from the outer surface of the discharge container 11 of the dielectric barrier discharge lamp 10 to the inner face of the window member 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device having a dielectric barrier discharge lamp.

[0002]

2. Description of the Related Art In recent years, an object to be processed made of metal, glass, or another material is irradiated with vacuum ultraviolet rays having a wavelength of 200 nm or less. Technology
For example, a cleaning treatment technique for removing organic contaminants attached to the surface of the treatment object and an oxide film formation treatment technique for forming an oxide film on the surface of the treatment object have been developed and have been put to practical use.

A low-pressure mercury lamp that emits vacuum ultraviolet light having a wavelength of 185 nm, which is a resonance line of mercury, has been used as a lamp for performing such ultraviolet treatment. An appropriate excimer emission gas is filled in a discharge vessel constituted by a body, and a dielectric barrier discharge (also known as "ozonizer discharge" or "silent discharge") is issued in the discharge vessel. June 2001 Reprint, 7th edition second
See page 63. ), A dielectric barrier discharge lamp has been developed in which excimer is generated and excimer light is emitted. For example, Japanese Patent Application Laid-Open No. 1-144560
Japanese Patent Laid-Open Publication No. H11-15764 discloses a dielectric barrier discharge lamp in which a gas for excimer light emission is filled in a hollow cylindrical discharge vessel made of quartz glass, at least part of which is a dielectric.

In this dielectric barrier discharge lamp,
By using, for example, xenon gas as the gas for excimer emission, vacuum ultraviolet rays having a peak at a wavelength of 172 nm, which is excimer light by xenon excimer, are emitted, and a gas mixture of, for example, argon and chlorine gas is used as the gas for excimer emission. In this way, argon-
It is known that vacuum ultraviolet light having a peak at a wavelength of 175 nm, which is excimer light due to chlorine excimer, is emitted.

However, when the dielectric barrier discharge lamp is lit in air, the dielectric barrier discharge lamp is caused by vacuum ultraviolet rays from the dielectric barrier discharge lamp or corona discharge generated at the electrodes of the dielectric barrier discharge lamp. Since oxygen in the air around the body barrier discharge lamp reacts to generate ozone, there is a problem that the electrode is corroded by the generated ozone when used for a long time.
In addition, since the vacuum ultraviolet rays from the dielectric barrier discharge lamp are absorbed by oxygen in the air, there is a problem that the object to be processed cannot be irradiated with the vacuum ultraviolet rays with high efficiency. For this reason, when using the dielectric barrier discharge lamp, the light source device is configured by housing the dielectric barrier discharge lamp in a lamp house having a window member for extracting excimer light, Introducing an inert gas such as nitrogen gas into the lamp house of the light source device and discharging the gas in the lamp house reduce the concentration of oxygen and the like present in the lamp house. ing.

However, the above light source device has the following problems. (1) The material constituting the discharge vessel of the dielectric barrier discharge lamp includes a material having transparency to vacuum ultraviolet rays,
Specifically, so-called synthetic quartz glass having a high purity of silicon dioxide is used. However, in such a synthetic quartz glass, since the transmittance of vacuum ultraviolet rays decreases as the temperature increases, the period from when the dielectric barrier discharge lamp is turned on until the temperature of the discharge vessel becomes stable is increased. ,
As the lighting time elapses, the amount of vacuum ultraviolet rays emitted from the dielectric barrier discharge lamp decreases.

(2) FIG. 4 is a diagram showing the relationship between the introduction time of nitrogen gas into the lamp house and the oxygen concentration in the lamp house, and FIG. 5 is the introduction of nitrogen gas into the lamp house. It is a figure showing the relation between time and the amount of vacuum ultraviolet rays emitted from the window member of the lamp house. As shown in FIG. 4, the oxygen concentration in the lamp house becomes about 500 ppm in 15 minutes after the introduction of nitrogen gas is started, but thereafter gradually decreases. Requires a considerably long time after the introduction of nitrogen gas is started. Then, as shown in FIG. 5, from the start of the introduction of the nitrogen gas into the lamp house to the time when the oxygen concentration becomes a constant value, as the introduction time of the nitrogen gas elapses, that is, in the lamp house, As the oxygen concentration decreases, the amount of vacuum ultraviolet rays emitted from the window member of the lamp house increases.

For the above reasons, in the conventional light source device provided with the dielectric barrier discharge lamp, the operation is started until the amount of the vacuum ultraviolet rays radiated from the window member of the lamp house is stabilized after the operation is started. It took a fairly long time.

In order to solve such a problem, an optical sensor for detecting the amount of vacuum ultraviolet light from the dielectric barrier discharge lamp is disposed in the lamp house, and the amount of ultraviolet light detected by the optical sensor is constant. Means for feedback-controlling the power supplied to the dielectric barrier discharge lamp so that the value becomes a value can be considered. However, it has been found that simply arranging the optical sensor in the lamp house cannot stabilize the amount of vacuum ultraviolet rays emitted from the window member of the lamp house in a short time. The reason is,
It is estimated as follows.

FIG. 6 is a diagram showing the relationship between the oxygen concentration in the lamp house and the amount of vacuum ultraviolet rays emitted from the window member of the lamp house. As shown in this figure, when the oxygen concentration in the lamp house is 450 ppm or less, the amount of vacuum ultraviolet light radiated from the window member is stable regardless of the value of the oxygen concentration. That is, when the oxygen concentration in the lamp house is 450 ppm or less, it is considered that the absorption of vacuum ultraviolet rays by the oxygen in the lamp house is small enough to be ignored. On the other hand, when the oxygen concentration in the lamp house exceeds 450 ppm, the amount of vacuum ultraviolet rays radiated from the window member sharply increases as the oxygen concentration decreases. That is, when the oxygen concentration in the lamp house exceeds 450 ppm, it is considered that absorption of vacuum ultraviolet rays by oxygen in the lamp house cannot be ignored. Therefore, depending on where the optical sensor is located in the lamp house, a large difference occurs between the amount of vacuum ultraviolet light detected by the optical sensor and the amount of vacuum ultraviolet light emitted from the window member,
As a result, the amount of vacuum ultraviolet rays emitted from the window member cannot be stabilized until the oxygen concentration in the lamp house becomes 450 ppm or less.

[0011]

DISCLOSURE OF THE INVENTION The present invention has been made based on the above circumstances, and its object is to provide:
In a light source device in which a dielectric barrier discharge lamp that emits ultraviolet light is housed in a lamp house having a window member, a light source capable of stabilizing the amount of ultraviolet light emitted from the window member of the lamp house in a short time It is to provide a device.

[0012]

SUMMARY OF THE INVENTION A light source device according to the present invention includes a dielectric barrier discharge lamp in which excimer is generated in a discharge vessel by dielectric barrier discharge and ultraviolet rays are emitted, and the dielectric barrier discharge lamp is housed therein. A lamp house having a window member for extracting ultraviolet rays from the dielectric barrier discharge lamp; and an optical sensor provided in the lamp house for detecting the amount of ultraviolet rays from the dielectric barrier discharge lamp. A light source device in which electric power supplied to the dielectric barrier discharge lamp is feedback-controlled so that the amount of ultraviolet light detected by the optical sensor becomes a constant value, wherein the discharge container of the dielectric barrier discharge lamp is The distance from the outer surface of the light sensor to the light receiving portion of the optical sensor is from the outer surface of the discharge vessel of the dielectric barrier discharge lamp to the inner surface of the window member. Characterized in that substantially equal to the distance.

In the light source device according to the present invention, when xenon gas is sealed as a gas for excimer emission in the discharge vessel of the dielectric barrier discharge lamp, the outer surface of the discharge vessel of the dielectric barrier discharge lamp is provided. And the distance from the outer surface of the discharge vessel of the dielectric barrier discharge lamp to the inner surface of the window member is 16
mm or less.

[0014]

In the light source device described above, the light sensor detects the amount of ultraviolet light emitted from the dielectric barrier discharge lamp, and the power supplied to the dielectric barrier discharge lamp is adjusted so that the amount of ultraviolet light becomes a constant value. Feedback controlled. Thus, the distance from the outer surface of the discharge vessel of the dielectric barrier discharge lamp to the light receiving portion of the optical sensor is substantially equal to the distance from the outer surface of the discharge vessel of the dielectric barrier discharge lamp to the inner surface of the window member. Irrespective of the value of the oxygen concentration in the lamp house, the amount of ultraviolet light detected by the optical sensor is substantially equal to the amount of ultraviolet light radiated from the window member. The amount of ultraviolet light emitted from the window member can be stabilized in a short time.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a light source device according to the present invention will be described in detail. FIG. 1 is an explanatory cross-sectional view showing the configuration of an example of the light source device of the present invention. In this light source device, four dielectric barrier discharge lamps 10 each emitting vacuum ultraviolet rays are housed in a rectangular box-shaped lamp house 20 as a whole.

In the dielectric barrier discharge lamp 10,
As shown in FIG. 2, a hollow cylindrical discharge vessel 11 is provided. The discharge vessel 11 has a cylindrical one wall portion 12 made of a dielectric, and an outer diameter smaller than the inner diameter of the one wall material 12 arranged in the one wall material 12 along the cylinder axis. And the other wall material 13 made of a dielectric material having the following configuration. Both ends of the one wall material 12 and the other wall material 13 are joined by a sealing wall portion 14, and one wall material is formed. A cylindrical discharge space S is formed between the material 12 and the other wall material 13. The discharge vessel 11 is filled with an excimer emission gas.

The one wall member 12 of the discharge vessel 11 is provided with one ultraviolet-permeable electrode 16 made of a conductive material such as a wire mesh in close contact with the outer surface 15 thereof. The wall material 13 is provided with the other film-shaped electrode 18 made of aluminum so as to cover the outer surface 17 which is the inner peripheral surface thereof.

In the illustrated example, a deformed portion 19 is formed on one end of one wall member 12 of the discharge vessel 11 so as to protrude inward along the circumferential direction.
A getter accommodating chamber K communicating with the discharge space S is formed between the deformed portion 19 and the sealing wall section 14 on one end side, and a getter G made of, for example, a barium alloy is accommodated in the getter accommodating chamber K. I have. The getter G is heated by, for example, high frequency, so that a thin film made of barium is formed on the inner wall surface of the getter accommodating chamber K.

The dielectric material constituting the one wall member 12 and the other wall member 13 in the discharge vessel 11 is a dielectric material having a property of transmitting excimer light emitted in the discharge vessel 11, for example, synthetic quartz glass. Can be used. As the gas for excimer emission sealed in the discharge vessel 11, a gas that generates excimer that emits excimer light with a wavelength of 200 nm or less, for example, a xenon gas or a mixed gas of argon and chlorine can be used.

In the lamp house 20, a rectangular cylindrical frame member 21 is provided, and the frame member 21 receives the dielectric barrier discharge lamp 10 from the dielectric barrier discharge lamp 10 so as to hermetically close the lower opening 22 thereof. A window member 25 for extracting vacuum ultraviolet rays to the outside is provided, and a cooling block 30 made of aluminum is provided so as to close the upper opening 23 of the frame member 21. As a material for forming the window member 25, a material having transparency to vacuum ultraviolet rays from the dielectric barrier discharge lamp 10, for example, synthetic quartz glass can be used. The lamp house 2 is provided on one side of the frame member 21.
A gas introduction hole 26 for introducing an inert gas is formed in the inside of the frame member 21.
A gas exhaust hole 27 for exhausting the gas in 0 is formed.

On the lower surface of the cooling block 30 in the lamp house 20, a dielectric barrier discharge lamp 10 is provided, respectively.
Four grooves 3 having a semi-circular cross section having a diameter larger than the outer diameter of
1 are formed so as to be spaced apart from each other, and the dielectric barrier discharge lamp 10 is arranged along each of these grooves 31. Reference numeral 32 denotes a cooling fluid flow passage formed through the cooling block 30 for flowing the cooling fluid.

The cooling block 30 of the lamp house 20 is provided with an optical sensor 40 for detecting the amount of vacuum ultraviolet light from the dielectric barrier discharge lamp 10. More specifically, a recess 33 for receiving the optical sensor 40 is formed on the upper surface of the cooling block 30 at a position directly above the groove 31. A hole 34 is formed, and the optical sensor 40 is arranged in the recess 33 of the cooling block 30 so that the light receiving portion 41 faces the dielectric barrier discharge lamp 10 via the light introducing hole 34. The cooling block 30 has a side hole 35 that extends from the light introducing hole 34 to the lower surface of the cooling block 30. The distance D1 from the outer surface of the discharge vessel 11 of the dielectric barrier discharge lamp 10 to the light receiving portion 41 of the optical sensor 40 is equal to the distance D1 of the discharge vessel 11 of the dielectric barrier discharge lamp 10.
Is substantially equal to a distance D2 from the outer surface of the lamp housing 20 to the inner surface of the window member 25 of the lamp house 20.

In the above-described light source device, an inert gas such as nitrogen gas is introduced from the gas introduction hole 26 of the lamp house 20, and the lamp house 2 is introduced from the gas discharge hole 27.
The gas in the lamp house 20 is discharged by discharging the gas in the lamp house 20.
The inside is filled with an inert gas. At this time, the inert gas is also filled in the light introducing hole 34 of the cooling block 30 via the gap between the groove 31 of the cooling block 30 and the dielectric barrier discharge lamp 10 and the side hole 35. In the dielectric barrier discharge lamp 10,
When a voltage is applied between one electrode 16 and the other electrode 18, a dielectric barrier discharge occurs in a discharge space S in the discharge vessel 11. Excimer is generated, and excimer light by this excimer is radiated from the mesh of one electrode 16 through one wall member 12, and this excimer light is transmitted through the window member 25 of the lamp house 20 to the window member 25. Irradiation is performed on an object to be processed disposed immediately below. On the other hand, in the optical sensor 40, the light receiving portion 41 is irradiated with the vacuum ultraviolet rays from the dielectric barrier discharge lamp 10 through the light introducing hole 34 of the cooling block 30,
The amount of vacuum ultraviolet light is detected. Then, the power supplied to the dielectric barrier discharge lamp 10 is feedback-controlled so that the light amount detected by the optical sensor 40 becomes a constant value.

An example of the specifications of the light source device of the present invention is as follows. Dielectric barrier discharge lamp 10: discharge vessel 11; effective length 700 mm, one wall 12; made of synthetic quartz glass, outer diameter 26.5 m
m, thickness 1 mm, other wall 13; synthetic quartz glass, outer diameter 16 mm, thickness 1 mm, one electrode 16; stainless steel wire mesh, the other electrode 18; aluminum, excimer emission gas; xenon (radiation Peak wavelength of ultraviolet rays 172 nm), Rated power: 1800 W (13 lamps), Lamp house 20: Dimensions: 1000 mm × 920 mm × 100 mm, Window member 25: Synthetic quartz glass, 5.5 mm thick, Dielectric barrier discharge lamp 10 D1 from the outer surface of the discharge vessel 11 to the light receiving portion 41 of the optical sensor 40; 27 m
m, distance D2 from the outer surface of the discharge vessel 11 of the dielectric barrier discharge lamp 10 to the inner surface of the window member 25; 27 mm

The dielectric barrier discharge lamp 10 is turned on using the light source device A having the above-mentioned specifications while introducing nitrogen gas into the lamp house 20 at a flow rate of 40 l / min. The amount of emitted vacuum ultraviolet light was measured over time. In addition, the optical sensor 4 is placed on the outer surface of the discharge vessel 11 of the dielectric barrier discharge lamp 10.
Using a light source device B having the same specifications as the light source device A except that the distance D1 to the light receiving unit 41 of 0 is 52 mm, while introducing nitrogen gas into the lamp house 20 at a flow rate of 40 l / min, The body barrier discharge lamp 10 was turned on, and the amount of vacuum ultraviolet rays emitted from the window member 25 of the lamp house 20 was measured over time. The above results are shown in FIG.
Shown in In FIG. 3, the horizontal axis represents the lamp house 20.
The vertical axis indicates the amount of vacuum ultraviolet light emitted from the window member 25 of the lamp house 20 (100 hours after the start of the introduction of the nitrogen gas). Relative value when the value is set to 100). The plot indicated by the symbol ● indicates the light source device A (when the distance D1 from the outer surface of the discharge vessel 11 of the dielectric barrier discharge lamp 10 to the light receiving portion 41 of the optical sensor 40 is 27 mm).
The plots indicated by the symbols □ indicate the light source device B (the discharge vessel 11 of the dielectric barrier discharge lamp 10).
D1 from the outer surface of the optical sensor 40 to the light receiving section 41 of the optical sensor 40
Shows a measurement result of 52 mm).

As is apparent from FIG. 3, in the light source device A according to the present invention, one hour after the introduction of nitrogen gas is started.
It was confirmed that the amount of vacuum ultraviolet light emitted from the window member 25 of the lamp house 20 was stabilized in 5 minutes. On the other hand, in the light source device B, it took about one hour from the start of the introduction of the nitrogen gas until the amount of the vacuum ultraviolet rays emitted from the window member of the lamp house 20 was stabilized. .

According to the light source device described above, the distance D1 from the outer surface of the discharge vessel 11 of the dielectric barrier discharge lamp 10 to the light receiving portion 41 of the optical sensor 40 is equal to the distance D1 of the discharge vessel 11 of the dielectric barrier discharge lamp 10. Is substantially equal to the distance D2 from the outer surface of the lamp member 20 to the inner surface of the window member 25. Therefore, regardless of the value of the oxygen concentration in the lamp house 20, the amount of vacuum ultraviolet light detected by the optical sensor 40 The value is substantially equal to the amount of the emitted vacuum ultraviolet light.
Therefore, the dielectric barrier discharge lamp 1 is controlled so that the amount of vacuum ultraviolet light detected by the optical sensor 40 becomes a constant value.
The feedback control of the input power to zero makes it possible to stabilize the amount of vacuum ultraviolet rays emitted from the window member 25 of the lamp house 20 in a short time.

In the light source device of the present invention, when the discharge vessel 11 of the dielectric barrier discharge lamp 10 is filled with xenon gas as an excimer emission gas, that is, the dielectric barrier discharge lamp 10 has a peak at a wavelength of 172 nm. In the case of emitting vacuum ultraviolet light having
The distance D1 from the outer surface of the discharge vessel 11 of the dielectric barrier discharge lamp 10 to the light receiving portion 41 of the optical sensor 40, and the distance from the outer surface of the discharge vessel 11 of the dielectric barrier discharge lamp 10 to the inner surface of the window member 25. The difference from D2 is preferably 16 mm or less. Hereinafter, the reason will be described.

Generally, the transmittance T of light to a light absorbing medium
Is represented by the following equation (1), where c is an absorption coefficient and x is a transmission distance.

[0030]

## EQU1 ## Equation (1) T = exp (-c.x)

When the measurement result (see FIG. 3) of the amount of vacuum ultraviolet light emitted from the window member 25 of the lamp house 20 in the light source device B is analyzed, the maximum value of the amount of vacuum ultraviolet light is 116 (nitrogen gas). (The value when 15 minutes have passed since the start of the introduction), and an error of 16% has occurred. At this time, the oxygen concentration in the lamp house 20 is about 500 ppm (see FIG. 4). And this 16
% Error, the actual light amount value detected by the optical sensor 40 is 100, but the dielectric barrier discharge lamp 10
From the outer surface of the discharge vessel 11 to the light receiving portion 41 of the optical sensor 40.
Between the outer surface of the discharge vessel 11 of the dielectric barrier discharge lamp 10 and the inner surface of the window member 25, that is, the difference in the transmission distance of vacuum ultraviolet rays. It is considered something. Therefore, the absorption coefficient c of the gas in the lamp house 20 at the time when 15 minutes have elapsed since the introduction of the nitrogen gas was started is:
From the above equation (1), it is as follows.

[0032]

100/116 = exp１００−c · (52-2)
7) Δc = 0.0059

After starting the introduction of nitrogen gas, 1
When 5 minutes have elapsed, that is, when the oxygen concentration in the lamp house 20 is about 500 ppm, the maximum error between the amount of vacuum ultraviolet light radiated from the window member 25 and the amount of vacuum ultraviolet light detected by the optical sensor 40. Is controlled to 10% or less which is a practical error range, the distance D1 from the outer surface of the discharge vessel 11 of the dielectric barrier discharge lamp 10 to the light receiving portion 41 of the optical sensor 40 and the dielectric barrier discharge The window member 25 extends from the outer surface of the discharge vessel 11 of the lamp 10.
The difference X from the distance D2 to the inner surface may be set to a maximum of 16 mm from the following formula.

[0034]

## EQU3 ## 100/110 = exp (−0.0059 ·
X) X ≒ 16

Accordingly, when the discharge vessel 11 of the dielectric barrier discharge lamp 10 contains xenon gas as an excimer emission gas, light from the outer surface of the discharge vessel 11 of the dielectric barrier discharge lamp 10 is emitted. The distance D1 to the light receiving portion 41 of the sensor 40 and the dielectric barrier discharge lamp 1
By setting the difference between the distance D2 from the outer surface of the discharge vessel 11 to the inner surface of the window member 25 to 16 mm or less, the amount of vacuum ultraviolet rays radiated from the window member 25 of the lamp house 20 can be reduced for a short time, for example, by nitrogen gas. 1 since we started introducing
It can be stabilized within 5 minutes. The value of the absorption coefficient c does not match the known absorption coefficient of oxygen for ultraviolet rays. The reason is that gases other than nitrogen and oxygen, such as ozone and water vapor, are present in the lamp house 20, and the ultraviolet light absorption coefficient of these gases is much larger than that of oxygen. It is believed that there is. In FIG. 4, the rate of decrease of the oxygen concentration with respect to the elapsed time from the start of the introduction of the nitrogen gas is smaller than the rate of decrease of the oxygen concentration expected from the inner volume of the lamp house 20 and the flow rate of the nitrogen gas. Low. It is considered that the reason is that it takes time to release the adsorbed and stored oxygen between the surfaces inside the lamp house 20 and the joint surfaces of the assembled parts. It is considered that such a phenomenon also occurs for water vapor.

[0036]

According to the light source device of the present invention, the distance from the outer surface of the discharge vessel of the dielectric barrier discharge lamp to the light receiving portion of the optical sensor is determined by the distance from the outer surface of the discharge vessel of the dielectric barrier discharge lamp. Since it is substantially equal to the distance to the inner surface of the window member of the house, the amount of ultraviolet light detected by the optical sensor is substantially equal to the amount of ultraviolet light emitted from the window member regardless of the value of the oxygen concentration in the lamp house. Values are equal. Therefore, the power supplied to the dielectric barrier discharge lamp is feedback-controlled so that the amount of ultraviolet light detected by the optical sensor becomes a constant value, so that the amount of vacuum ultraviolet light radiated from the window member of the lamp house is reduced. It can be stabilized in a short time.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view schematically showing a configuration of an example of a light source device of the present invention.

FIG. 2 is an explanatory sectional view showing a configuration of an example of a dielectric barrier discharge lamp used in the present invention.

FIG. 3 is a diagram showing the relationship between the introduction time of nitrogen gas into a lamp house and the amount of vacuum ultraviolet light emitted from a window member of the lamp house in the light source device of the present invention.

FIG. 4 is a diagram showing the relationship between the introduction time of nitrogen gas into a lamp house and the oxygen concentration in the lamp house.

FIG. 5 is a diagram showing the relationship between the introduction time of nitrogen gas into a lamp house and the amount of vacuum ultraviolet light emitted from a window member of the lamp house in a conventional light source device.

FIG. 6 is a diagram showing the relationship between the oxygen concentration in a lamp house and the amount of vacuum ultraviolet light emitted from a window member of the lamp house in a conventional light source device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Dielectric barrier discharge lamp 11 Discharge container 12 One wall part 13 The other wall part 14 Sealing wall part 15 Outer surface of one wall part 16 One electrode 17 Outer surface of the other wall part 18 The other electrode 19 Deformation part 20 Lamp house 21 Frame material 22, 23 Opening 25 Window member 26 Gas introduction hole 27 Gas exhaust hole 30 Cooling block 31 Groove 32 Cooling fluid flow passage 33 Depression 34 Light introduction hole 35 Side hole 40 Optical sensor 41 Light receiving unit G Getter K Getter storage room S discharge space

Claims (2)

[Claims] 1. A dielectric barrier discharge lamp in which an excimer is generated in a discharge vessel by a dielectric barrier discharge to emit ultraviolet rays, an ultraviolet ray containing the dielectric barrier discharge lamp, and the ultraviolet rays from the dielectric barrier discharge lamp A lamp house having a window member for taking out the light, and an optical sensor provided in the lamp house, for detecting the amount of ultraviolet light from the dielectric barrier discharge lamp. A light source device in which the input power to the dielectric barrier discharge lamp is feedback-controlled so that the light amount becomes a constant value, wherein the power from the outer surface of the discharge vessel of the dielectric barrier discharge lamp to the light receiving unit of the optical sensor is adjusted. The distance is substantially equal to the distance from the outer surface of the discharge vessel of the dielectric barrier discharge lamp to the inner surface of the window member. Light source device. 2. A discharge vessel of a dielectric barrier discharge lamp is filled with xenon gas as an excimer emission gas, and a gas from an outer surface of the discharge vessel of the dielectric barrier discharge lamp to a light receiving portion of an optical sensor is provided. The light source device according to claim 1, wherein a difference between the distance and a distance from an outer surface of a discharge vessel of the dielectric barrier discharge lamp to an inner surface of the window member is 16 mm or less.