JP2009151969A - Excimer lamp, its manufacturing method, and light source - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excimer lamp for radiating high output excimer lamp, and its manufacturing method, and a light source. <P>SOLUTION: The excimer lamp and the method for manufacturing the excimer lamp are characterized by that the excimer lamp includes a discharge vessel containing discharge gas therein, and a plurality of electrodes for applying a voltage to the discharge gas. Concentration of residual air in the discharge vessel is 2500 ppb or less. The manufacturing method of the excimer lamp is characterized by that the discharge gas is filled after the concentration of the residual air in the discharge vessel is controlled to be 2500 ppb or less in a state that the discharge gas is filled. The light source is characterized by the excimer lamp and a power supply for applying a high frequency voltage on a plurality of electrodes for forming the excimer lamp. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an excimer lamp that emits excimer light, a manufacturing method thereof, and a light source device.

  Conventionally, excimer light has been emitted to an object to be processed using an excimer lamp in order to cure a paint or to perform surface cleaning or surface modification of a semiconductor wafer or glass substrate. .

Excimer light is radiation generated by applying a voltage to a discharge gas such as a rare gas. For example, when xenon (Xe) is used as a discharge gas, xenon ( Xe) is (generated xenon excited atoms (Xe ^*) is by colliding with e) ((1) electronic), Xe excimer a triple collision of xenon excited atoms (Xe ^*) and xenon (Xe) ( Xe ₂ ^* ) is generated (formula (2)), and then when the Xe excimer (Xe ₂ ^* ) relaxes (returns to the ground state), vacuum ultraviolet (VUV) light having a high photon energy hν is emitted ( (Formula (3)) is known (for example, see Non-Patent Document 1).
(1) e + Xe → e + Xe ^*
(2) Xe ^* + Xe + Xe → Xe ₂ ^* + Xe
(3) Xe ₂ ^* → 2Xe + hν

  As a method for emitting such excimer light, a method using dielectric barrier discharge (ozonizer discharge) is known, but with the progress of microfabrication technology in the electronics field, higher output VUV light is emitted. Excimer lamps are now being sought.

Bee. B. Eliasson et al., “UV Excimer Radiation from Dielectric-Barrier Discharges”, Applied Physics B, 1988, Vol. 46, p. 299-303

An object of the present invention is to provide an excimer lamp capable of emitting excimer light with higher output under such circumstances.
Another object of the present invention is to provide a method and a light source device for manufacturing an excimer lamp.

  As a result of extensive studies by the present inventors, a discharge vessel including a discharge gas therein and a plurality of electrodes for applying a voltage to the discharge gas, the residual atmosphere in the discharge vessel The inventors have found that the above object can be achieved with an excimer lamp having a concentration ratio of 2500 ppb or less in partial pressure ratio, and have completed the present invention based on this finding.

That is, the present invention
(1) A discharge vessel comprising a discharge gas therein and a plurality of electrodes for applying a voltage to the discharge gas, wherein the concentration of residual air in the discharge vessel is 2500 ppb or less. Excimer lamp,
(2) The excimer lamp according to (1), wherein the discharge generated between the plurality of electrodes is a glow discharge.
(3) The excimer lamp according to (1) or (2), wherein the discharge gas includes xenon gas,
(4) A method for manufacturing the excimer lamp according to any one of (1) to (3) above, wherein the concentration of the residual air inside the discharge vessel is 2500 ppb or less after filling with the discharge gas. Excimer lamp manufacturing method characterized by filling discharge gas after adjustment,
(5) The excimer lamp manufacturing method according to (4), wherein the concentration adjustment of the residual air is performed by a decompression process,
(6) The method for manufacturing an excimer lamp according to (4) or (5), wherein the concentration adjustment of the residual air is performed by a replacement treatment with an inert gas,
(7) The excimer lamp manufacturing method according to (6), wherein the inert gas replacement treatment is repeated twice or more.
(8) The excimer lamp manufacturing method according to (6) or (7) above, wherein the inert gas is xenon gas, and (9) the excimer lamp according to any one of (1) to (3) above, A light source comprising: an excimer lamp obtained by the method according to any one of (4) to (8) above; and a power source for applying a high-frequency voltage to a plurality of electrodes constituting the excimer lamp. A device is provided.

  According to the present invention, it is possible to provide an excimer lamp capable of emitting higher-power excimer light, and according to the present invention, a method for manufacturing the excimer lamp and a light source device using the excimer lamp are provided. Can be provided.

First, the excimer lamp of the present invention will be described.
The excimer lamp of the present invention has a discharge vessel containing a discharge gas therein and a plurality of electrodes for applying a voltage to the discharge gas, and the concentration of residual air in the discharge vessel is 2500 ppb or less. It is characterized by being.

  In this specification, an excimer lamp means a discharge lamp that emits excimer light in its operation, but the name is not necessarily unified in general, and in this specification, these discharge lamps are collectively referred to. "Excimer lamp".

  Embodiments of an excimer lamp according to the present invention will be described below with reference to the drawings. Examples of the excimer lamp of the present invention include excimer lamps I and II described below.

(Excimer lamp I)
FIG. 1A is a schematic cross-sectional view for explaining the configuration of the excimer lamp I. FIG.
In FIG. 1A, an excimer lamp 1 has a discharge vessel 2 and a pair of discharge electrodes 3 disposed to face each other, and a discharge gas 4 in the discharge vessel 2 is provided with a discharge gas. Is filled.

  In FIG. 1A and FIG. 2, the discharge vessel 2 has a substantially rectangular parallelepiped shape, but the shape of the discharge vessel 2 has an airtight structure that can enclose a discharge gas therein. In addition to the rectangular parallelepiped shape, various shapes such as a cubic shape, a cylindrical shape, and a double cylindrical shape can be adopted. Further, in order to obtain high-output excimer light, a plurality of discharge spaces may be formed inside the discharge vessel. As such a discharge vessel, a plurality of discharge spaces are provided in parallel inside as described later. It is preferable to use a discharge vessel.

  The discharge vessel 2 in which the discharge space 4 is formed is formed of a dielectric material. As this dielectric material, a known material such as synthetic quartz glass, calcium fluoride, magnesium fluoride or the like is used. be able to.

  The discharge vessel 2 shown in FIG. 2 has a rectangular parallelepiped shape having a width of 60 mm, a height of 80 mm, and a thickness of 8 mm. The discharge vessel 2 preferably has a width of 20 to 500 mm and a height of 20 to 500 mm. It is preferable that the thickness is 2 to 20 mm.

  As shown in FIG. 1A, an excimer lamp is formed by providing electrodes 3 and 3 on the main surface of the discharge vessel 2, and the electrodes 3 and 3 and the high-frequency power source 6 provided outside are electrically connected. By connecting to, a light source device to be described later is formed. In FIG. 1A, the electrode 3 has a flat plate shape, but the shape of the electrode is not particularly limited, and various shapes can be taken in consideration of the shape of the discharge vessel and the like.

  When the electrode 3 has a flat plate shape, the size is preferably about 2 to 50 cm in length, 2 to 50 cm in width, and about 0.2 to 5.0 mm in thickness.

  The material of the electrode 3 is not particularly limited as long as it is a conductive material capable of generating excimer light between the electrodes, but various metal materials such as aluminum, stainless steel, and monel metal, and an aluminum film or a dielectric multilayer film on the metal surface. It is preferable that it is provided. The metal on which the aluminum film or the dielectric multilayer film is provided on the surface is preferably copper, silver, gold or the like in view of conductivity and thermal conductivity. Moreover, as the dielectric multilayer film, a film in which magnesium fluoride films and lithium fluoride films are alternately laminated is preferable. In addition, by making the electrode structure net-like or punching metal, excimer light can be emitted from a surface orthogonal to the discharge path (surface on which the electrode 3 is provided in the discharge vessel 2).

  In FIG. 1A, a discharge gas is enclosed in a discharge space 4 formed inside the discharge vessel 2, and a voltage is applied from a high frequency power source 6 to the flat electrodes 3 and 3. As a result, the discharge gas sealed in the discharge vessel 6 generates a discharge, and transmits excimer light through the light emission surface 21 parallel to the discharge path.

  Examples of the discharge gas include a rare gas such as xenon gas, or a mixed gas of rare gas and chlorine. The center wavelength of the obtained excimer light is determined by the type of discharge gas, and is, for example, around 170 nm in the case of xenon gas.

  The discharge type of the discharge gas is not particularly limited. For example, a dielectric barrier discharge that discharges an excimer lamp while repeatedly applying a high voltage of about 10 kV or a dielectric breakdown after applying a high voltage at the start of lighting is performed. An example is glow discharge in which discharge is performed by applying a relatively low high-frequency voltage.

(Excimer lamp II)
FIG. 1B is a schematic cross-sectional view for explaining the configuration of the excimer lamp II.
In FIG. 1B, the excimer lamp 1 has a light emission window 25 provided in the light emitting direction, and a plurality of electrodes 3 for voltage application arranged to face each other. The discharge gas existing in the discharge space 4 formed between the three generates discharge and emits excimer light, and the excimer discharge electrode 3 is a plate electrode, and the plate electrodes 3 having different polarities. Are alternately arranged via the dielectric 9, so that a plurality of the discharge spaces 4 are provided in parallel between the plate-like electrodes 3 and 3, and a light emission window 25 is provided in parallel to the discharge path of the discharge space It is what was done.

  Also in the excimer lamp II, a light source device to be described later can be formed by connecting the electrode 3 shown in FIG. 1B and the high frequency power source 6, and by applying a voltage from the high frequency power source 6, The discharge gas existing in the discharge space 4 generates a discharge, and excimer light can be emitted from the light emission window 25.

  The light emission window 25 shown in FIG. 1 (b) has a main surface having a round shape, but the shape of the light emission window 25 is not particularly limited, and the main surface has a round shape. Various types such as a surface having a quadrangular shape can be employed, and those having a main surface having a round shape are preferable from the viewpoint of availability. The material of the light emission window 25 is not particularly limited, but in consideration of cost and strength, synthetic quartz glass, magnesium fluoride crystal, calcium fluoride crystal and the like are preferable. Moreover, when the size of the light emission window 25 is round, the diameter is preferably about 2 to 60 cm, and the thickness is preferably about 2 to 50 mm.

  In the excimer lamp II, the discharge vessel 2 has a cylindrical shape, but the shape of the discharge vessel is not particularly limited as long as it has an airtight structure that can enclose an inert gas therein. In addition to the cylindrical shape, various shapes such as a cubic shape and a rectangular parallelepiped shape can be employed. As described above, since the light emission window is preferably round from the viewpoint of availability, the shape of the discharge vessel is also preferably cylindrical. When the shape of the discharge vessel is cylindrical, the size is preferably about 10 to 70 cm in diameter, 10 to 80 cm in height, and about 1 to 10 mm in thickness of the side wall. In the excimer lamp II, the material of the discharge vessel is not particularly limited, but is preferably a material that easily dissipates heat and does not easily generate impurity gas, and examples thereof include stainless steel and aluminum. In the excimer lamp II, it is preferable to provide a gasket, an O-ring or the like between the light emission window 25 and the discharge vessel 2 to ensure airtightness.

  Also in the excimer lamp II, the shape, size, material, type of discharge gas, discharge type of the discharge gas, etc. are the same as those in the excimer lamp I.

  As shown in FIG. 1B, in the excimer lamp II, the light emitting unit 24 may have a top plate 29 or a reflection mirror 28.

  In the excimer lamp II, the electrode 3 is a flat electrode, a plurality of discharge spaces 4 are provided between the flat electrodes 3, and the light emission window 25 is provided in parallel with the discharge path of the discharge space. In addition, by forming the electrode into a flat plate shape, the distance between the excimer discharge electrodes 3 and 3 from the opposite side of the light emitting surface (the upper side of FIG. 1B) to the light emitting surface (the lower side of FIG. 1B). A wide discharge space 4 can be formed, and excimer light generated at an arbitrary position between the excimer discharge electrodes 3 and 3 can be integrated, and high-power excimer light can be extracted from the light exit window 25. It becomes.

  In the excimer lamp of the present invention, the most characteristic point is that the concentration of the residual atmosphere in the discharge vessel 2 is 2500 ppb or less.

  That is, the present inventors have found that the emission intensity of excimer light can be increased by controlling the concentration of the atmosphere remaining in the discharge vessel to 2500 ppb or less in the discharge vessel 2. The present invention has been achieved based on the findings.

  The lower the residual atmospheric concentration contained in the discharge gas, the higher the excimer light radiation intensity obtained, so the residual atmospheric concentration is preferably 1500 ppb or less, and more preferably 500 ppb or less.

  In the present specification, the residual atmospheric concentration is the pressure when the atmosphere in the discharge vessel is evacuated before filling the discharge gas (the pressure in the discharge vessel after evacuation), and the pressure after filling the discharge gas ( It means a value divided by the atmospheric pressure in the discharge vessel after filling the discharge gas, and is obtained by the following formula 1.

(Formula 1)

  As described above, the excimer lamp of the present invention is characterized in that the concentration of the residual atmosphere in the discharge vessel 2 is 2500 ppb or less. Therefore, this point will be described below with reference to FIGS. This will be described in detail.

  FIG. 3 is a diagram showing a device configuration for measuring the spectral radiation intensity of the vacuum ultraviolet light emitted from the excimer lamp 1 shown in FIG.

  The excimer lamp 1 is housed in an airtight lamp vessel 5 filled with nitrogen gas, and a pair of electrodes 3 and 3 are connected to a high frequency power source 6 provided outside.

  The voltage applied to the electrodes 3 and 3 is a high-frequency voltage of 700 Vrms and a frequency of 2 MHz. A glow discharge is generated in the discharge space 4 and excimer light is emitted.

  A light extraction window 52 made of magnesium fluoride is provided on the wall surface 51 of the lamp vessel 5 facing the light emission surface 21 of the discharge vessel 2, and excimer light including vacuum ultraviolet light emitted from the excimer lamp is supplied to the lamp vessel. It can be taken out.

  Excimer light that has passed through the light extraction window 52 is dispersed by a VUV spectrometer 7 (manufactured by ACTON: VM502), and is irradiated on a light receiving surface (not shown) of an X-ray CCD 8 (manufactured by Princeton Instrument: 7344-0004). .

  In this measurement, seven types of excimer lamps having a residual atmospheric concentration in the range of 0.4 ppb to 4000 ppb while having 500 Torr of xenon gas as the discharge gas inside the discharge vessel 2. (A) to (g) were manufactured, and the spectral radiant intensity of excimer light in the vacuum ultraviolet region emitted from each lamp was measured.

  FIG. 4 is a diagram showing the spectral radiation characteristics of excimer light emitted from the seven types of excimer lamps in the range of 140 nm to 210 nm.

  FIG. 4 shows that in any excimer lamp, vacuum ultraviolet light is emitted in the wavelength range of 155 nm to 190 nm, and the residual atmospheric concentration in the discharge gas decreases (from (g) to (a). It can be seen that the peak radiation intensity around the wavelength of 170 nm increases as it goes.

  In the above measurement, the high frequency voltage applied to each of the excimer lamps having different residual air concentrations is set to 700 Vrms constant and the frequency is set to 2 MHz. Next, excimer light emission when the applied voltage is changed from 700 Vrms to 1000 Vrms. The change in intensity will be described.

  FIG. 5 shows the relationship between the high-frequency voltage applied to each excimer lamp and the peak radiation intensity of excimer light emitted from the excimer lamp.

  It is known that glow discharge occurs when power is supplied to an excimer lamp such as a xenon excimer lamp at a frequency in the MHz band used in this measurement.

  From FIG. 5, as the voltage applied to each excimer lamp is increased, the radiation intensity of the glow discharge increases in any excimer lamp, but the graph shows the lower the residual atmospheric concentration in the discharge vessel. It can be seen that the slope increases and the degree of increase in radiation intensity increases.

  Further, in glow discharge, it is known that several filament discharges are generated in the discharge space depending on the voltage application condition, and the radiation intensity rapidly decreases. The region that corresponds to the region where the filamentary discharge occurs, but the maximum applied voltage that can maintain the glow-like discharge can be applied to a lamp with a lower residual atmospheric concentration, As a result, it can be seen that excimer light with high radiation intensity can be obtained.

  FIG. 6 is a plot of the relationship between the residual atmospheric concentration in the discharge vessel of the excimer lamps (a) to (g) and the peak emission intensity of excimer light near the wavelength of 170 nm at the maximum applied voltage. The residual atmospheric concentration (ppb) and the vertical axis indicate the radiation intensity (relative value).

  As shown in FIG. 6, the excimer light radiation intensity gradually increases in the region where the residual atmospheric concentration is 2500 ppb or less. At the residual atmospheric concentration of 1500 ppb, the radiation intensity becomes 1.5 times the residual atmospheric concentration of 4000 ppb. It can be seen that the radiation intensity increases rapidly in the region of 500 ppb or less.

  Thus, in an excimer lamp that supplies a high frequency voltage to the discharge gas sealed in the discharge vessel 2 and emits excimer light, the residual atmospheric concentration contained in the discharge gas is set to 2500 ppb or less, It is possible to increase the radiation intensity of excimer light.

Next, the manufacturing method of the excimer lamp of this invention is demonstrated.
The excimer lamp manufacturing method of the present invention is a method of manufacturing the above-described excimer lamp of the present invention, wherein after adjusting the concentration of the residual air inside the discharge vessel to a concentration of 2500 ppb or less after charging the discharge gas. In addition, the discharge gas is filled.

  Preferred embodiments for carrying out the method of the present invention include the excimer lamp production method I and the excimer lamp production method II, as will be described below. Each embodiment will be described below with reference to the drawings. Shall.

<Excimer lamp manufacturing method I>
Excimer lamp manufacturing method I is a method in which the concentration of residual air is adjusted by a reduced pressure treatment, and specific examples thereof include manufacturing method I-1 and manufacturing method I-2.

(Production method I-1)
FIG. 7 is a schematic cross-sectional view of an apparatus configuration for explaining the production method I-1, and shows an apparatus configuration for filling the discharge vessel 2 shown in FIGS. 1 (a) and 2 with a discharge gas.

  The apparatus shown in FIG. 7 includes a discharge vessel 2, a pressure gauge 10, a discharge gas cylinder 11, a scroll pump 12, a turbo molecular pump 13, valves V <b> 1 to V <b> 4, and stainless steel tubes connecting them.

  The wall surface of the discharge vessel 2 facing the light exit surface 21 is provided with a filling port 23 for charging a discharge gas, and the filling port 23 is connected to the bulb V1.

  As shown in FIG. 7, valves V2, V3, V4 and a pressure gauge 10 are connected to the valve V1, a discharge gas cylinder 11 is connected to the valve V2, a turbo molecular pump 12 is connected to the valve V3, A scroll pump 13 is connected to V4.

  The exhaust side 121 of the turbo molecular pump 12 is connected to the intake side 131 of the scroll pump 13.

Below, the example of a procedure which fills the discharge gas to the discharge vessel 2 with the manufacturing method I-1 is shown.
[Exhaust step]
1. The valves V2 and V3 are closed, the valves V1 and V4 are opened, the scroll pump 13 is started, and the inside of the discharge vessel is exhausted.
2. When the pressure in the discharge vessel 2 is 1 × 10 ⁻² Torr or less, the valve V4 is closed, the valve V3 is opened, and the turbo molecular pump 12 is started.
3. When the inside of the discharge vessel 2 reaches a predetermined pressure, the valves V3 and V4 are closed, and the scroll pump 13 and the turbo molecular pump 12 are stopped.
[Encapsulation step]
1. With the valves V3 and V4 closed, the valve V2 is opened, and a discharge gas (for example, xenon gas) is filled until the inside of the discharge vessel reaches a predetermined pressure.
2. All the bulbs are closed and the filling port 23 of the discharge vessel 2 is sealed.

  In the above procedure, by setting the atmospheric pressure in the discharge vessel after exhaust in the exhaust step to a predetermined value, the inside of the discharge vessel can be set to a desired residual atmospheric concentration based on Equation 1.

In the exhaust step, it is usually possible to exhaust with a scroll pump if the pressure is up to about 1 × 10 ⁻³ Torr, but it is necessary to enhance the exhaust capacity with a turbo molecular pump or the like in a region below this range Therefore, when manufacturing an excimer lamp having a residual atmospheric concentration of 200 ppb or less, it is preferable to perform exhaust using the turbo molecular pump 12 in combination.

  The excimer lamp can be manufactured by providing a plurality of electrodes on the main surface of the discharge vessel 2 after adjusting the concentration of the residual air in the discharge vessel 2 to a desired concentration by the above process. It should be noted that a desired excimer lamp can be manufactured by providing a plurality of electrodes on the main surface of the discharge vessel 2 in advance and adjusting the residual atmospheric concentration.

(Production method I-2)
FIG. 8 is a schematic sectional view of an apparatus configuration for explaining the production method I-2, and shows an apparatus configuration for filling the discharge vessel 2 shown in FIG. 1B with a discharge gas.

The production method I-2 is different from the production method I-1 only in the shape of the excimer lamp.
In FIG. 8, the excimer lamp 1 has a light emission window 25 provided in the light emitting direction, and a plurality of electrodes 3 for voltage application arranged to face each other, and is parallel between the opposed electrodes 3 and 3. The discharge gas present in the discharge space 4 formed in this way generates a discharge and emits excimer light.

  In the excimer lamp 1 shown in FIG. 8, the discharge spaces 4 are arranged in parallel between the plate-like electrodes 3 and 3 by arranging the plate-like electrodes 3 of different polarities alternately through the dielectrics 9 in the discharge vessel 2. A plurality of light emission windows 25 are provided in parallel to the discharge path of the discharge space 4.

  The discharge vessel 2 can be filled with the discharge gas in the same procedure as in the production method I-1.

  In the excimer lamp 1 shown in FIG. 8, the filling port is not sealed after the discharge gas is sealed in the discharge vessel, and the pressure is used to replenish the discharge gas when the discharge gas leaks from the discharge vessel 2. It is possible to keep the discharge gas filling device such as the total 10, the discharge gas cylinder 11, and each pump connected.

<Excimer lamp manufacturing method II>
In the excimer lamp manufacturing method II, the concentration of the residual air is adjusted by a replacement treatment with an inert gas.

  In the excimer lamp production method II, the inert gas replacement treatment may be performed only once, but may be repeated two or more times. If the number of replacement treatments is increased in this way, the residual air concentration is further reduced. Can do.

  The inert gas may be the same as or different from the discharge gas. For example, in addition to a rare gas such as helium gas, neon gas, argon gas, krypton gas, or xenon gas, nitrogen may be used. Gas etc. can be mentioned.

  In the excimer lamp manufacturing method II, the residual atmospheric concentration can be adjusted to a desired concentration in a short time by performing the inert gas substitution process as compared with the case where the pressure inside the discharge vessel is simply reduced.

  Specific embodiments of Excimer Lamp Production Method II include Production Method II-1 and Production Method II-2 as shown below.

(Production II-1)
In this aspect, by adding a replacement step and a secondary exhaust step to the process of filling the discharge gas, the pressure in the discharge vessel reached in each exhaust step is set high, and the exhaust in each exhaust step is The time required for this can be shortened.

  As shown in FIG. 9, the production method II-1 is an embodiment in which the discharge gas sealed in the discharge gas cylinder 11 is also used as an inert gas in the replacement process.

  FIG. 9 is a schematic cross-sectional view showing an apparatus configuration for filling the excimer lamp 1 with a discharge gas by the manufacturing method II-1, and the turbo molecular pump 12 and the valve V3 connected to the turbo molecular pump from the configuration shown in FIG. The configuration is excluded.

Below, the example of a procedure which fills the discharge container 2 with the gas for discharge by manufacturing method II-1.
[Primary exhaust step]
1. The valve V2 is closed, the valves V1 and V4 are opened, the scroll pump 13 is started, and the inside of the discharge vessel is exhausted.
2. When the inside of the discharge vessel 2 reaches a predetermined pressure, the valve V4 is closed and the scroll pump 13 is stopped.
[Replacement step]
1. With the bulb V4 closed, the bulb V2 is opened and the discharge vessel 2 is filled with a discharge gas (inert gas) until a predetermined atmospheric pressure is reached.
2. When the inside of the discharge vessel 2 reaches a predetermined pressure, the bulb V2 is closed.
[Secondary exhaust step]
1. With the valve V2 closed, the valve V4 is opened, the scroll pump 13 is activated, and the inside of the discharge vessel is exhausted.
2. When the inside of the discharge vessel reaches a predetermined pressure, the valve V4 is closed and the scroll pump 13 is stopped.
[Encapsulation step]
1. With the bulb V4 closed, the bulb V2 is opened and the discharge vessel 2 is filled with a discharge gas until a predetermined atmospheric pressure is reached.
2. When the inside of the discharge vessel reaches a predetermined pressure, all the valves are closed.

  In the above embodiment, the replacement process with the inert gas is performed only once. However, when the residual atmospheric concentration is to be further reduced, it is preferable to repeat the replacement process twice or more.

(Production Method II-2)
As described above, the production method II-1 is an embodiment in which the discharge gas sealed in the discharge gas cylinder 11 is also used as an inert gas in the replacement processing step, whereas the production method II-2 includes: In this embodiment, a gas different from the discharge gas is used as the inert gas.

  FIG. 10 is an apparatus configuration diagram for explaining the production method II-2. FIG. 10 is different from FIG. 9 in that an inert gas cylinder 14 is provided separately from the discharge gas cylinder 11.

  Of the atmospheric components remaining in the discharge vessel, the oxygen atom is considered to have the greatest effect as a component that inhibits the emission of excimer light in the vacuum ultraviolet region. Therefore, in the substitution step shown in the above-mentioned production method II-1 Used a discharge gas as a replacement gas, but in the production method II-2, other inert gases such as nitrogen gas not containing oxygen atoms can be used.

  For example, as shown in FIG. 10, a cylinder 14 filled with an inert gas such as nitrogen gas is arranged in parallel with a cylinder 11 filled with a discharge gas such as xenon gas. In a case where the replacement step is changed to a procedure that is repeated not only once but also twice, the first replacement step may be performed using nitrogen gas.

  The production method II-2 has an advantage that a relatively inexpensive gas can be used, although the intensity of excimer light emitted from the obtained excimer lamp may be reduced as compared with the production method II-1.

Next, the light source device of the present invention will be described.
The light source device of the present invention comprises the excimer lamp of the present invention or the excimer lamp obtained by the method of the present invention, and a power source for applying a high-frequency voltage to a plurality of electrodes constituting the excimer lamp. To do.
Examples of the excimer lamp and the power source that constitute the light source device are the same as those described above.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.

Example 1 (Example of excimer lamp and light source device manufacture by excimer lamp manufacturing method I-1)
Excimer lamps were manufactured by the apparatus configuration shown in FIG.
In this example, xenon gas was used as the discharge gas, and the xenon gas was sealed in the discharge vessel 2 by the following procedure.
[Exhaust step]
1. The valves V2 and V3 were closed, the valves V1 and V4 were opened, the scroll pump 13 was started, and the inside of the discharge vessel 2 was exhausted.
2. The valve V4 was closed, the valve V3 was opened, and the turbo molecular pump 12 was started.
3. When the atmospheric pressure in the discharge vessel 2 reached 2 × 10 ⁻⁷ Torr, the valves V3 and V4 were closed, and the scroll pump 13 and the turbo molecular pump 12 were stopped.
[Encapsulation step]
1. With the bulbs V3 and V4 closed, the bulb V2 was opened and filled with xenon gas until the inside of the discharge vessel reached 500 Torr.
2. All the bulbs were closed and the filling port 23 of the discharge vessel 2 was sealed.
With the above operation, the residual atmospheric concentration in the discharge vessel 2 was set to 0.4 ppb.
An excimer lamp was manufactured by sandwiching the discharge vessel 2 between two flat electrodes, and a light source device was manufactured by connecting the flat electrode and a high-frequency power source.

Example 2 (Example of excimer lamp and light source device production by excimer lamp manufacturing method I-2)
An excimer lamp and a light source device were manufactured by an excimer lamp manufacturing method I-2 with an apparatus configuration as shown in FIG. The internal capacity of the discharge vessel 2 constituting the excimer lamp 1 used in the present embodiment is about 60 liters, and the discharge space is obtained by arranging the plate electrodes 3 having different polarities alternately through the dielectrics 9. 4 is provided in parallel between the flat electrodes 3, 3, and the light emission window 25 is provided in parallel with the discharge path of the discharge space 4.
The discharge vessel 2 was filled with xenon gas in the same procedure as in Example 1 to produce an excimer lamp having a residual atmospheric concentration of 0.4 ppb and a light source device having the excimer lamp.

  For comparison, an excimer lamp similar to the excimer lamp obtained in this example was manufactured except that the residual atmospheric concentration was 4000 ppb, and a light source device having the excimer lamp was manufactured.

Using the light source device having an excimer lamp having a residual atmospheric concentration of 0.4 ppb and the light source device having an excimer lamp having a residual atmospheric concentration of 4000 ppb, a glow discharge can be maintained from the high frequency power source 6 to the electrode 3. A high frequency voltage of 2 MHz was applied at the maximum voltage, and the radiation intensity of excimer light having a peak wavelength near 170 nm was measured.
As a measurement method, a light-receiving surface of an ultraviolet intensity meter (manufactured by Ushio Electric: UIT150 / VUV-S172) (not shown) was brought into close contact with the light emission window 25 in the vicinity of the center of the light emission window 25 on the emission side.

As a result of the measurement, the vacuum ultraviolet light of the light source device having an excimer lamp having a residual atmospheric concentration of 0.4 ppb against the vacuum ultraviolet light radiation intensity of 43 mW / cm ² of the light source device having an excimer lamp having a residual atmospheric concentration of 4000 ppb. The radiant intensity was 170 mW / cm ² , and excimer light having a radiant intensity of about 4 times was obtained.

Example 3 (Example of manufacturing excimer lamp and light source device by excimer lamp manufacturing method II-1)
An excimer lamp and a light source device were manufactured by an apparatus configuration as shown in FIG.
In this example, xenon gas was used as the discharge gas, and the xenon gas was sealed in the discharge vessel 2 by the following procedure.
[Primary exhaust step]
1. The valve V2 was closed and the valves V1 and V4 were opened to activate the scroll pump 13 to evacuate the discharge vessel.
2. When the atmospheric pressure in the discharge vessel reached 1 × 10 ⁻² Torr, the valve V4 was closed and the scroll pump 13 was stopped.
[Replacement step]
1. With the bulb V4 closed, the bulb V2 was opened, and the discharge vessel 2 was filled with xenon gas until the atmospheric pressure in the vessel reached 500 Torr.
2. After the atmospheric pressure in the discharge vessel 2 reached 500 Torr, the bulb V2 was closed.
At this time, the residual atmospheric concentration in the discharge vessel 2 was 20 ppm. The time required from the start of the primary exhaust step to the end of the replacement step was about 20 minutes.
[Secondary exhaust step]
1. With the valve V2 closed, the valve V4 was opened and the scroll pump 13 was started to evacuate the discharge vessel.
2. When the atmospheric pressure in the discharge vessel reached 1 × 10 ⁻² Torr, the valve V4 was closed and the scroll pump 13 was stopped.
[Encapsulation step]
1. With the bulb V4 closed, the bulb V2 was opened and filled with xenon gas until the pressure inside the discharge vessel 2 reached 500 Torr.
2. When the inside of the discharge vessel reached 500 Torr, all the bulbs were closed.

  At this time, the residual atmospheric concentration in the discharge vessel 2 was 0.4 ppb. The time required from the start of the secondary exhaust step to the end of the sealing step was about 20 minutes.

  The excimer lamp having a residual atmospheric concentration of 0.4 ppb obtained in Example 2 required about 50 hours to reduce the atmospheric components remaining in the discharge vessel to a predetermined amount in one exhaust step. However, by adding a replacement step and a secondary exhaust step to the discharge gas sealing procedure, it is possible to perform a process that previously required 50 hours in 40 minutes, which significantly increases the time required for charging the discharge gas. Could be shortened.

  Further, according to the procedure for sealing the discharge gas into the discharge vessel 2 according to the present embodiment, it is possible to use an exhaust pump having a relatively low exhaust capability as the exhaust pump of the discharge vessel 2, so that Cost could be reduced.

Example 4 (Example of excimer lamp and light source device manufacture by excimer lamp manufacturing method II-1)
An excimer lamp and a light source device were manufactured by an apparatus configuration as shown in FIG.
In this example, xenon gas was used as the discharge gas, and the xenon gas was sealed in the discharge vessel 2 by the following procedure.
[Primary exhaust step]
1. The valve V2 was closed and the valves V1 and V4 were opened to activate the scroll pump 13 to evacuate the discharge vessel.
2. When the pressure inside the discharge vessel reached 5 × 10 ⁻¹ Torr, the valve V4 was closed and the scroll pump 13 was stopped.
[Primary replacement step]
1. With the bulb V4 closed, the bulb V2 was opened, and the discharge vessel 2 was filled with xenon gas until the atmospheric pressure in the vessel reached 500 Torr.
2. After the atmospheric pressure in the discharge vessel 2 reached 500 Torr, the bulb V2 was closed.
At this time, the residual atmospheric concentration in the discharge vessel 2 was 1000 ppm. Further, the time required from the start of the primary exhaust step to the end of the primary replacement step was about 6 minutes.
[Secondary exhaust step]
1. With the valve V2 closed, the valve V4 was opened and the scroll pump 13 was activated to evacuate the discharge vessel.
2. When the atmospheric pressure in the discharge vessel reached 5 × 10 ⁻¹ Torr, the valve V4 was closed and the scroll pump 13 was stopped.
[Secondary replacement step]
1. With the bulb V4 closed, the bulb V2 was opened, and the discharge vessel 2 was filled with xenon gas until the atmospheric pressure in the vessel reached 500 Torr.
2. After the atmospheric pressure in the discharge vessel 2 reached 500 Torr, the bulb V2 was closed.
At this time, the residual atmospheric concentration in the discharge vessel 2 was 1 ppm. The time required from the start of the secondary exhaust step to the end of the secondary replacement step was about 6 minutes.
[Tertiary exhaust step]
1. With the valve V2 closed, the valve V4 was opened and the scroll pump 13 was started to evacuate the discharge vessel.
2. When the atmospheric pressure in the discharge vessel reached 2 × 10 ⁻¹ Torr, the valve V4 was closed and the scroll pump 13 was stopped.
[Encapsulation step]
1. With the bulb V4 closed, the bulb V2 was opened and filled with xenon gas until the pressure inside the discharge vessel 2 reached 500 Torr.
2. When the inside of the discharge vessel reached 500 Torr, all the bulbs were closed.

  At this time, the residual atmospheric concentration in the discharge vessel 2 was 0.4 ppb. Further, the time required from the start of the tertiary exhaust step to the end of the sealing step was about 8 minutes.

  The excimer lamp obtained in Example 3 required 40 minutes to make the residual atmospheric concentration in the discharge vessel 0.4 ppb, but in Example 4, the secondary replacement step and the tertiary exhaust step were performed. By combining, it was possible to carry out the above treatment in 20 minutes, and the time required for enclosing the discharge gas could be further shortened.

  Further, according to the procedure of filling the discharge gas into the discharge vessel 2 according to the present embodiment, an exhaust pump having a relatively low exhaust capability can be used as the exhaust pump of the discharge vessel 2 as in the third embodiment. Therefore, the cost for manufacturing equipment could be reduced.

  Using the light source devices having the excimer lamps obtained in Example 3 and Example 4, respectively, in the same manner as in Example 2, the maximum voltage capable of maintaining glow discharge from the high-frequency power source 6 to the electrode 3 with a frequency of 2 MHz. A high frequency voltage was applied, and the radiation intensity of excimer light having a peak wavelength near 170 nm was measured. As a result, in any light source device, as in the excimer lamp shown in the second embodiment, it is possible to obtain excimer light having a radiation intensity about four times that of the excimer lamp having a residual atmospheric concentration of 4000 ppb. It was.

  ADVANTAGE OF THE INVENTION According to this invention, the excimer lamp which can radiate | emit higher output excimer light can be provided, and the method and light source device which manufacture the said excimer lamp can be provided.

It is a schematic sectional drawing of the excimer lamp for demonstrating the structure of the excimer lamp of this invention. It is explanatory drawing of the discharge vessel which comprises the excimer lamp of this invention. It is a figure which shows the apparatus structure for measuring the spectrum radiation intensity of the vacuum ultraviolet light radiated | emitted from an excimer lamp. It is a figure which shows the spectral radiation characteristic in the range of 140 nm to 210 nm of the excimer light radiated | emitted from an excimer lamp. It is a relationship figure between the high frequency voltage applied to an excimer lamp, and the peak radiation intensity of the excimer light radiated | emitted from an excimer lamp. It is the figure which plotted the relationship between the residual atmospheric concentration in the discharge vessel which comprises an excimer lamp, and the peak radiation intensity of the excimer light of wavelength 170nm vicinity in the maximum applied voltage. It is a figure explaining an example of the manufacturing method of the excimer lamp in this invention. It is a figure explaining an example of the manufacturing method of the excimer lamp in this invention. It is a figure explaining an example of the manufacturing method of the excimer lamp in this invention. It is a figure explaining an example of the manufacturing method of the excimer lamp in this invention.

Explanation of symbols

1 Excimer lamp 2 Discharge vessel 3 Electrode 4 Discharge space 5 Vessel 6 High frequency power supply

Claims (9)

  An excimer comprising: a discharge vessel containing a discharge gas therein; and a plurality of electrodes for applying a voltage to the discharge gas, wherein the concentration of residual air in the discharge vessel is 2500 ppb or less. lamp.   The excimer lamp according to claim 1, wherein the discharge generated between the plurality of electrodes is a glow discharge.   The excimer lamp according to claim 1, wherein the discharge gas contains xenon gas.   A method for producing an excimer lamp according to any one of claims 1 to 3, wherein the concentration of the residual air inside the discharge vessel is adjusted to a concentration of 2500 ppb or less after charging the discharge gas. A method for manufacturing an excimer lamp, which is filled with a discharge gas.   The excimer lamp manufacturing method according to claim 4, wherein the concentration adjustment of the residual atmosphere is performed by a decompression process.   6. The method of manufacturing an excimer lamp according to claim 4, wherein the concentration adjustment of the residual atmosphere is performed by an inert gas replacement process.   The excimer lamp manufacturing method according to claim 6, wherein the inert gas replacement treatment is repeated twice or more.   The method for manufacturing an excimer lamp according to claim 6 or 7, wherein the inert gas is xenon gas.   The excimer lamp according to any one of claims 1 to 3 or the excimer lamp obtained by the method according to any one of claims 4 to 8, and a plurality of electrodes constituting the excimer lamp, a high frequency voltage And a power source for applying the light source.

Images