JP2006120392A - Excimer lamp lighting device and excimer lamp lighting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excimer lamp lighting device capable of irradiation treatment of uniform excimer light when lowering the voltage to be impressed on the excimer lamp by keeping frequencies of high-frequency power to be supplied to the excimer lamp from 1MHz to 1GHz, by shortening the time needed until discharge plasma is uniformly distributed in a whole discharging space. <P>SOLUTION: The excimer lamp lighting device is composed of an excimer lamp 7 having a discharging container, in which discharge gas generating excimer molecules by discharge is filled; a lighting circuit part 20 lighting the excimer lamp 7 with supply of high-frequency electric power of 1MHz to 1GHz; and a control part 10. The control part 10 controls the lighting circuit part 20 so as to supply a power higher than the stationary power supplied at stationary lighting of the excimer lamp 7 during the starting period of the excimer lamp, and supply the stationary power after the excimer lamp is moved into a stationary lighting state. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an excimer lamp lighting device and an excimer lamp lighting method, and more particularly to an excimer lamp that is lit by being supplied with a high-frequency power of a high frequency such as 1 MHz to 1 GHz. The present invention relates to an excimer lamp lighting device having an excimer lamp that emits light emitted from the light source and an excimer lamp lighting method.

  Conventionally, an excimer lamp has been used as one of vacuum ultraviolet light radiation sources having high efficiency radiation performance for processing such as curing, dry cleaning, sterilization, surface modification, and photo-CVD using a photochemical reaction. A typical excimer lamp is an excimer lamp that uses an excimer-generating gas such as a rare gas and a dielectric between electrodes that supply high-frequency power, and uses discharge through the dielectric between the electrodes. ing.

  FIG. 6 is a diagram illustrating an example of a surface cleaning apparatus using an excimer lamp lighting device. In this figure, the surface cleaning apparatus 100 is configured such that a light extraction window member 107 made of, for example, quartz glass is disposed between a lamp house 101 and a processing chamber 102. In the lamp house 101, for example, a cooling block 117 made of aluminum is provided. On the lower surface of the cooling block 117, there are provided a plurality of groove portions 117a each having a semicircular cross section, as shown in FIG. The plurality of groove portions 117a are formed so that the longitudinal directions thereof are perpendicular to the paper surface and are arranged substantially parallel to each other. In each of the groove portions 117a, a cylindrical excimer lamp 104 having an outer diameter that matches the inner diameter of the groove portion 117a is disposed.

FIG. 7 is an explanatory view showing a configuration example of the excimer lamp 104 and shows a cross section along the tube axis.
In the excimer lamp 104, for example, a cylindrical outer tube 104a made of a dielectric such as quartz glass and a cylindrical inner tube 104b made of a dielectric such as quartz glass and having an outer diameter smaller than the inner diameter of the outer tube 104a. Are arranged coaxially. Both end portions of the outer tube 104a and the inner tube 104b are hermetically sealed to form a discharge vessel. For example, xenon is enclosed as a discharge gas in the discharge space 118 which is a sealed cylindrical space constituted by the outer tube 104a and the inner tube 104b. On the outer surface of the outer tube 104a, for example, a mesh electrode 103a made of nickel is disposed, and on the inner surface of the inner tube 104b, for example, a metal cylindrical electrode 103b made of aluminum is disposed.
High-frequency power is supplied from the high-frequency high-voltage power source 105 between the electrodes 103a and 103b. In FIG. 6, the high frequency high voltage power source 105 is connected to one excimer lamp 104, but actually, the high frequency high voltage power source 105 is connected to all the excimer lamps 104.
Here, the electrode 103a provided on the outer tube 104a side is grounded. Further, the connection between the electrode 103b provided on the inner tube 104b side and the high-frequency high-voltage power source 105 is made on one end side of the electrode 103b. Hereinafter, this connection portion is referred to as a power feeding unit 119.
When a high frequency voltage is supplied to the electrodes 103a and 103b, discharge plasma is generated in the discharge space 118, excimer molecules of the discharge gas sealed in the discharge space 118 are formed, and light is emitted from the excimer molecules. When the discharge gas is xenon, vacuum ultraviolet light having a center wavelength of 172 nm is emitted.

Returning to FIG. 6, the light emitted from the excimer lamp 104 disposed in the lamp house 101 passes through the mesh portion of the mesh electrode 103a, for example, and passes through the light extraction window member 107 to the processing chamber 102 side. To be taken out.
Here, the cooling block 117 is for cooling each excimer lamp 104 by heat exchange. Depending on the lighting conditions of the excimer lamp 104, a space (not shown) may be provided in the cooling block 117, and the cooling water may be circulated in the space.
Further, the surface of the cooling block 117 facing the light extraction window member 107 may be processed into a mirror surface, for example. By processing in this way, the light emitted from the excimer lamp 104 efficiently reaches the light extraction window member 107.

An object 109 to be processed is placed on the sample stage 108 in the processing chamber 102. The object to be processed 109 is, for example, a glass substrate for liquid crystal display. When cleaning a glass substrate for liquid crystal display, for example, the processing chamber is filled with an oxidizing fluid. This oxidizing fluid contains oxygen. For example, a mixed gas of oxygen and nitrogen is used as the oxidizing fluid. That is, high-purity air is supplied into the processing chamber 102 from the gas supply means 116 a that supplies high-purity air through the oxidizing fluid inlet 106 a provided in a part of the processing chamber 102.
The discharge gas of each excimer lamp 104 is xenon, and vacuum ultraviolet light having a center wavelength of 172 nm emitted from the excimer lamp 104 side is introduced into the surface of the workpiece 109 and the processing chamber 102 through the light extraction window member 107. Irradiated to an oxidizing fluid (mixed gas of oxygen and nitrogen). Oxygen in the mixed gas of oxygen and nitrogen reacts with vacuum ultraviolet light to generate oxygen radicals. This oxygen radical reacts with the organic impurities on the object to be processed 109 (glass substrate for liquid crystal display) to generate hydrocarbons, carbon dioxide, and water in the processing chamber 102, which are discharged to the oxidizing fluid outlet. 106 b is exhausted by exhaust means 116 b connected to the oxidizing fluid discharge port 106 b.
Here, 120 is a control means, which sends on / off signals to the high-frequency high-voltage power supply 105 to control on / off of the high-frequency high-voltage power supply 105, thereby turning on / off each excimer lamp 104. Control. The control unit 120 is also configured to control the gas supply unit 116 a and the exhaust unit 116 b to comprehensively control the illuminance and timing of the gas supply, exhaust, and light irradiation of the excimer lamp 104 in the processing chamber 102. May be.

By the way, when the excimer lamp is turned on, conventionally, a high frequency power of a frequency of several tens of KHz is supplied as a high frequency power from the high frequency high voltage power source 105, and a discharge plasma is uniformly formed in the entire discharge space of the excimer lamp and stably maintained. The steady lighting state was realized.
However, when the excimer lamp is turned on with high frequency power of several tens of kilohertz, a very high voltage such as about 5 kV is required as an applied voltage, and sufficient measures are required for insulation of devices and the like. . Such countermeasures have problems that the apparatus itself becomes large and costs increase.
In order to cope with such a problem, there is a method of setting the frequency of the applied high frequency power to several MHz as described in Patent Document 1 for the purpose of reducing the applied voltage during steady lighting. In this case, for example, an excimer lamp that has been lit at an applied voltage of 5 kV can be steadily lit at an applied voltage of about 1 kV.
JP 2000-331649 A

  However, especially when a high-frequency power having a frequency of several MHz is applied to a large-sized, high-power excimer lamp, the discharge plasma is applied to the entire excimer lamp, that is, the entire discharge space after the high-frequency power is supplied. It has been found that a new problem occurs that takes time to spread evenly. This is a phenomenon that has not been confirmed when the excimer lamp is turned on with a high frequency power of several tens KHz as in the prior art.

FIG. 8 is a diagram schematically illustrating the result of detailed observation of this phenomenon. The growth of the discharge plasma is such that the discharge plasma 200 generated by dielectric breakdown in the vicinity of the power supply unit 119 of the excimer lamp 104 at the start of discharge starts from the power supply unit 119 side (in order of FIGS. 8A, 8B, 8C, and 8D). ) And gradually spread in the tube axis direction of the excimer lamp 104.
The phenomenon in which the discharge plasma gradually spreads in the tube axis direction of the excimer lamp 104 is particularly noticeable as the excimer lamp 104 has a longer overall length and as the pressure of the sealed gas sealed in the discharge space 118 of the excimer lamp 104 increases. Appeared. Further, the lower the steady power supplied when the excimer lamp 104 is steadily lit, the longer it takes to grow the discharge plasma. Depending on the supplied power, the phenomenon that the discharge plasma does not spread throughout the excimer lamp 104, for example, FIG. As shown in FIG. 9, a phenomenon has occurred in which the discharge plasma grows only about 30% of the length from the feeding portion 119 in the tube axis direction.
When the irradiation process is performed in such a state, a problem that the object to be processed is processed unevenly occurs. In addition, if processing is performed after the discharge plasma has sufficiently grown in the tube axis direction of the excimer lamp 104, non-uniform processing can be avoided, but the processing takes time, and in particular, production that repeats lighting and flashing repeatedly. The line had a problem that the throughput was greatly reduced.

  The object of the present invention is to set the frequency of the high frequency power applied to the excimer lamp to 1 MHz to 1 GHz, which is higher than the conventional several tens of KHz, and lower the applied voltage when the excimer lamp is turned on than before. Even during lighting, there is no spatial non-uniformity in the discharge space of the discharge plasma, it is possible to reduce the time until the discharge plasma is uniformly distributed throughout the discharge space, and further lighting that repeats lighting flashing The present invention also provides an excimer lamp lighting device and an excimer lamp lighting method capable of performing uniform excimer light irradiation processing.

In order to solve the above problems, the present invention employs the following means. The first means includes an excimer lamp in which a discharge gas for generating excimer molecules by discharge is filled in a discharge vessel, and the excimer. In an excimer lamp lighting device comprising a lighting circuit section for turning on an excimer lamp by supplying high-frequency power having a frequency of 1 MHz to 1 GHz to the lamp, and a control section, the control section is configured so that the excimer lamp starts during the excimer lamp start-up period. Control the lighting circuit unit to supply the excimer lamp with power higher than the steady power supplied during steady lighting of the lamp, and after the excimer lamp enters the steady lighting state, supply the steady power to the excimer lamp. This is an excimer lamp lighting device.

  The second means is the first means, wherein the control unit has lighting detection means for detecting that the excimer lamp has shifted to steady lighting, and supplies the excimer lamp to the excimer lamp based on a signal from the lighting detection means. The excimer lamp lighting device is characterized in that a command signal for instructing to switch the power to be switched from higher power to steady power than during steady lighting is sent to the lighting circuit section.

  According to a third means, in the first means, the control unit has a timer means for sending a signal after a predetermined time from the start of the excimer lamp, and supplies the signal to the excimer lamp based on the signal from the timer means. An excimer lamp lighting device is characterized in that a command signal for instructing to switch power from higher power to steady power than during steady lighting is sent to the lighting circuit section.

  The fourth means is set in the third means so that the predetermined time substantially coincides with the time until the excimer lamp starts when the electric power higher than the steady power is supplied and shifts to the steady lighting. This is an excimer lamp lighting device.

  A fifth means is an excimer lamp lighting device according to any one of the first means to the fourth means, wherein the sealed pressure of the discharge gas is 10 kPa or more at room temperature.

  A sixth means is an excimer lamp lighting method in which a high frequency power having a frequency of 1 MHz to 1 GHz is supplied to an excimer lamp in which a discharge gas that generates excimer molecules by discharge is filled in a discharge vessel. During the start-up period, power higher than the steady power supplied when the excimer lamp is steadily lit is supplied to the excimer lamp, and after the excimer lamp enters the steady lit state, the steady power is supplied to the excimer lamp. Excimer lamp lighting method.

  According to the excimer lamp lighting device of the present invention, the frequency of the high-frequency power supplied to the excimer lamp is 1 MHz to 1 GHz, and higher power than the steady power supplied when the excimer lamp is steadily turned on is supplied during the excimer lamp start-up period. As a result, it is possible to shorten the start-up period, which is the time required from the start of the excimer lamp until the discharge plasma completely spreads over the entire discharge space of the excimer lamp.

  Furthermore, since the discharge plasma can be spread quickly and uniformly in the direction of the tube axis of the discharge space of the excimer lamp, even when this excimer lamp is applied to a production line that repeatedly turns on and off, it is instantaneously stable over a wide area. Excimer light can be irradiated.

In addition, after the excimer lamp shifts to the steady lighting state, the steady power is supplied to the excimer lamp, so there is no case where excessive power is applied during steady lighting, and the heat generation amount of the excimer lamp increases. There is no longer a problem.
Even when the discharge vessel of the excimer lamp is made of quartz glass, there are problems such as ultraviolet distortion of the quartz glass due to undesired intensity of excimer light (ultraviolet light, vacuum ultraviolet light) and a decrease in the excimer light transmittance of the quartz glass. It no longer occurs.

  Further, a lighting detection means for detecting that the excimer lamp has shifted to the steady lighting state is provided, and the power supplied to the excimer lamp based on the lighting detection signal from the lighting detection means is steady from a higher power than that during steady lighting. Since switching to electric power has been made, it has become possible to reliably switch the power supplied to the excimer lamp.

  The excimer lamp is provided with a timer means for sending a signal after a lapse of a certain time from when the excimer lamp is started after the power supply until the discharge plasma is uniformly generated in the entire discharge space, and based on the signal from the timer means. Since the power supplied to the power source is switched from higher power to steady power than during steady lighting, the power supplied to the excimer lamp can be switched reliably.

  In addition, since the frequency of the high frequency power supplied to the excimer lamp is set to 1 MHz to 1 GHz, the applied voltage to the excimer lamp can be made lower than that in the case of supplying high frequency power having a frequency of several tens of KHz. It can also have conventional effects.

First, the background to the invention of each embodiment shown below will be described. As a result of diligent research on the excimer lamp lighting device, the inventors have increased the power supplied to the excimer lamp when the high-frequency excimer lamp is turned on by supplying high-frequency power having a frequency of 1 MHz or higher. It has been found that the discharge plasma grows in the discharge space and the spatial non-uniformity is eliminated, and the time until the discharge plasma is uniformly distributed throughout the discharge space is shortened.
Therefore, the time until the discharge plasma is reliably generated uniformly in the entire discharge space is short, and the discharge plasma in the discharge space as shown in FIG. It has been found that the problem as described above can be avoided by supplying the excimer lamp with such a power that does not occur.

The reason for this is not clear, but is considered as follows. That is, the discharge part formed from the discharge gas in the outer tube 104a, the inner tube 104b, the electrodes 103a and 103b, and the discharge space 118 of the excimer lamp seems to form a distributed constant circuit. Therefore, the potential at the electrode 103a decreases as the distance from the power supply unit 119 increases in the tube axis direction.
This tendency becomes conspicuous when the frequency of the high frequency high voltage applied between the electrodes 103a and 103b becomes a high frequency of 1 MHz or more. Therefore, the phenomenon in which discharge plasma grows along the tube axis direction in order from the portion close to the power feeding unit 119 in the discharge space becomes significant.
Therefore, if the power supplied to the excimer lamp is increased, sufficient power to cause dielectric breakdown in the discharge space 118 can be obtained at a position near the power supply unit 119 even at a position away from the power supply unit 119 in the tube axis direction. It can be supplied almost simultaneously. It is considered that the time until the discharge plasma is reliably generated uniformly in the entire discharge space can be shortened.

  When the frequency of the high-frequency power supplied to the excimer lamp is about several tens of KHz in the related art, the rate at which the potential at the electrode 103a decreases as it moves away from the power supply unit 119 in the tube axis direction is small. Therefore, when power for turning on the excimer lamp is supplied, it is considered that discharge plasma was generated uniformly in the entire discharge space 118 in an instant.

  By the way, in general, when electric power is supplied to an excimer lamp and dielectric breakdown occurs in the discharge space to form discharge plasma, the discharge impedance in the region where the discharge plasma is formed decreases. Therefore, once the discharge plasma is formed, the power for maintaining the discharge plasma, that is, the steady power supplied when the excimer lamp is steadily lit, may be lower than the power supplied when the discharge breakdown is generated.

Therefore, based on the knowledge found by the inventors, the time until the discharge plasma is reliably and uniformly generated in the entire discharge space is short, and the discharge plasma in the discharge space is generated unevenly. If power that does not result in the above state is continuously supplied to the excimer lamp, excessive power may be supplied during steady lighting after the discharge plasma is uniformly generated in the entire discharge space.
In other words, the excimer lamp is supplied with power that is larger than the steady power that is necessary for maintaining the discharge plasma during steady lighting. In this case, the amount of heat generated in the excimer lamp becomes large and the cooling structure becomes large. Further, since the supplied power is larger than the steady power, the intensity of excimer light becomes larger than that during steady power supply. Therefore, when the discharge vessel of the excimer lamp is made of quartz glass, problems such as ultraviolet distortion of the quartz glass caused by undesired intensity of excimer light (ultraviolet light, vacuum ultraviolet light) and a decrease in the excimer light transmittance of the quartz glass may occur. Is also possible.

  Therefore, the discharge plasma is reliably generated uniformly throughout the discharge space during the excimer lamp start-up period, which is the period from when power is supplied and the excimer lamp starts until the discharge plasma is uniformly generated throughout the discharge space. Power is supplied to the excimer lamp so that the discharge plasma in the discharge space is not generated in a non-uniform manner, and the discharge plasma is uniformly generated in the entire discharge space. After that, it is desirable to reduce the power supplied to the excimer lamp to the above-described steady power. By doing so, it is possible to obtain a desired excimer light intensity when the excimer lamp is steadily lit. Further, the heat generation amount of the excimer lamp can be suppressed to a predetermined value.

Next, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a diagram showing a configuration of an excimer lamp lighting device according to the invention of this embodiment.
The excimer lamp lighting device of the present embodiment includes an excimer lamp 7, a lighting circuit unit 20 that supplies power to the excimer lamp, and a control unit 10 that is a control unit that controls the operation of the lighting circuit unit 20. In general, it is preferable to provide a matching circuit 6 including a capacitor and an inductance between the lighting circuit unit 20 and the excimer lamp 7 for impedance matching between the lighting circuit unit 20 and the excimer lamp 7.
A specific configuration example of the excimer lamp 7 is shown in FIG. Since this specific configuration example is the same as that shown in FIG. 7, the detailed description is omitted here.

  The control unit 10 detects the lighting switch circuit 1, the logic circuit 4 that performs AND operation, and the steady lighting state of the excimer lamp 7, that is, the state in which the discharge plasma is uniformly generated in the discharge space 118 of the excimer lamp shown in FIG. And a lighting detection circuit 9 that outputs a lighting detection signal based on a light detection signal from the lighting detection means 8.

  The lighting detection means 8 is composed of, for example, a photodiode or the like, and outputs a light detection signal when receiving light. As shown in FIG. 2, when a discharge occurs in the discharge space 118 of the excimer lamp 7, visible light and near infrared light are also emitted in addition to the excimer light. Therefore, the wavelength of the light received by the detection means 8 may be the wavelength of excimer light, the wavelength of visible light, or near infrared light.

As described above with reference to FIG. 8, the discharge plasma generated in the discharge space 118 of the excimer lamp 7 grows from the power supply unit 119 to which the power from the lighting circuit unit 20 is supplied. The power feeding unit 119 is often provided on one end side of the excimer lamp 7 as shown in FIG. 2 in view of ease of actual assembly of the excimer lamp 7 and measures against heat of wiring.
Therefore, if the lighting detection means 8 is arranged at the other end portion of the excimer lamp 7 where the discharge plasma grows and reaches, the discharge plasma is discharged into the entire discharge space 118 when the lighting detection means 8 detects the light from the excimer lamp 7. Can be detected.
If two lighting detection means 8 are installed so as to detect the light at both ends of the excimer lamp 7 as shown in the figure, the discharge plasma is spread over the entire discharge space 118 regardless of the position where the power supply unit 119 is provided. Can be detected as a complete spread.

  The lighting circuit unit 20 includes a function generator 2 that transmits a high-frequency sine wave signal, and amplifier means 5 that amplifies the high-frequency sine wave signal from the function generator 2 and outputs high-frequency power. The lighting circuit unit 20 corresponds to the high frequency high voltage power source 105 in FIG.

Here, the frequency range of the high frequency sine wave signal transmitted from the action generator 2 is 1 MHz to 1 GHz. Therefore, the frequency range of the high frequency power output from the amplifier means 5 is 1 MHz to 1 GHz.
As described above, in the high-frequency power supplied to the excimer lamp 7, when the frequency is lower than 1 MHz, the voltage applied to the excimer lamp 7 becomes a high voltage, and sufficient measures are required for insulation of the device or the like. It is not preferable.
If the frequency exceeds 1 GHz, the power transmission structure becomes large. Therefore, in practice, the frequency range of the high frequency power supplied to the excimer lamp 7 is desirably 1 MHz to 1 GHz.

Next, the operation of the excimer lamp lighting device according to the invention of this embodiment will be described with reference to the timing charts shown in FIGS. As shown in FIG. 2, it is assumed that two (81, 82) lighting detection means 8 are provided near both ends of the excimer lamp 7.
First, from the lighting switch circuit 1 of the control unit 10, a start signal which is a lighting start command for the excimer lamp 7 is sent to the function generator 2 and the logic circuit 4 of the lighting circuit unit 20 (S101). The function generator 2 receives the start signal and sends a high-frequency sine wave signal to the amplifier means 5 (S102). The amplifier means 5 receives the high frequency sine wave signal from the function generator 2 and outputs high frequency power (S103). The output power is supplied to the excimer lamp 7 via the matching circuit 6.

  Here, the electric power amplified and output by the amplifier means 5 has a voltage frequency of 1 MHz to 1 GHz, and in the excimer lamp 7, the discharge plasma reliably grows in the entire discharge space 118 in a short time. It is set to such a value.

  When the excimer lamp 7 emits light and the lighting detection means 81 and 82 detect light emitted from the excimer lamp 7, a light detection signal is sent from the lighting detection means 81 and 82 to the lighting detection circuit 9 (S104, S105). ). When all the signals from the lighting detection means 81 and 82 are received, the lighting detection circuit 9 sends a lighting detection signal to the logic circuit 4 (S106). The logic circuit 4 calculates the logical product of the start signal from the lighting switch circuit 1 and the lighting detection signal from the lighting detection circuit 9, and sends a gain control signal to the amplifier means 5 (S107). Based on the gain control signal received from the lighting detection circuit 9, the amplifier means 5 changes the amplification factor and changes the value of the high-frequency power to be output (region to the right of the broken line in S103).

  Here, the power output from the amplifier means 5 with the amplification factor changed is the steady power supplied when the excimer lamp 7 is steadily lit. This steady power is set so that, for example, an excimer light intensity required in an optical processing apparatus using excimer light can be obtained.

Next, a description will be given of the results of a comparative experiment on the applied power during the start-up period using the excimer lamp lighting device. The structure of the excimer lamp used here is the same as that shown in FIG.
In the experiment, an excimer lamp having an outer diameter of 40 mm of the outer tube 104a and a length of 25 cm in the tube axis direction sealed with 50 kPa of xenon as a discharge gas was used. A power feeding unit 119 was connected to one end of the electrode 103b of the excimer lamp, and the time required for growth of the discharge plasma when the supplied power was changed was measured. Here, the frequency of the high-frequency power supplied to the excimer lamp was set to 4 MHz.

  First, when the power supplied to the excimer lamp during the start-up period is 200 W and the power supply after the discharge plasma spreads in the entire discharge space 118 is set to 100 W, the discharge plasma is completely spread over the entire discharge space 118 from the start. The time required for spreading (that is, the starting period) was 0.4 seconds. Further, even after the supply power was switched to 100 W, the discharge was maintained in a state where it spread over the entire discharge space 118. That is, a steady lighting state with an applied power of 100 W could be maintained.

  On the other hand, when the power supplied to the excimer lamp was fixed at 100 W from the start, it took 3 seconds for the discharge plasma to grow throughout the discharge space 118. Note that the steady lighting state was maintained after the discharge plasma spread.

  That is, during the start-up period of the excimer lamp, when power 200W larger than the power 100W at the time of steady lighting is applied to the excimer lamp, compared with the case where power of 100W is applied constantly from the start, the discharge space 118 from the start. It was confirmed that the time until the discharge plasma spreads throughout can be shortened.

Thus, according to the excimer lamp lighting device according to the invention of the present embodiment, the frequency of the high-frequency power supplied to the excimer lamp is set to 1 MHz to 1 GHz, and the power higher than the steady power supplied during steady lighting of the excimer lamp is obtained. Since the excimer lamp is supplied during the start-up period, it is possible to shorten the start-up period, which is the time required from the start of the excimer lamp until the discharge plasma completely spreads over the entire discharge space 118 of the excimer lamp. .
Furthermore, since the discharge plasma can be spread quickly and uniformly in the direction of the tube axis of the discharge space of the excimer lamp, even if this excimer lamp lighting device is applied to a production line that repeatedly turns on and off, an instantaneously stable excimer can be obtained. There is an advantage that light can be provided.

In addition, after the excimer lamp shifts to the steady lighting state, the steady power is supplied to the excimer lamp, so there is no case where excessive power is applied during steady lighting, and the heat generation amount of the excimer lamp increases. There is no longer a problem.
Even when the discharge vessel of the excimer lamp is made of quartz glass, there are problems such as ultraviolet distortion of the quartz glass due to undesired intensity of excimer light (ultraviolet light, vacuum ultraviolet light) and a decrease in the excimer light transmittance of the quartz glass. It no longer occurs.

  In particular, lighting detection means 8 (81, 82) for detecting that the excimer lamp has shifted to the steady lighting state and lighting detection means comprising the lighting detection circuit 9 are provided, and the excimer lamp is based on a signal from the lighting detection means. Since the power supplied to the power source is switched from higher power to steady power than during steady lighting, the power supplied to the excimer lamp can be switched reliably.

In addition, it is preferable that the enclosure pressure of discharge gas (for example, xenon) enclosed in the discharge space of an excimer lamp shall be 10 kPa or more at normal temperature. If it is less than 10 kPa, the intensity of excimer light taken out from the excimer lamp becomes small, which is not practical.
As described above, when the discharge gas charging pressure of the excimer lamp is increased, the start-up period becomes longer. By using the excimer lamp of the present invention, the discharge gas sealing pressure is 10 kPa or more at room temperature. It has become possible to shorten the starting period.

  Moreover, since the frequency of the high frequency power supplied to the excimer lamp is 1 MHz to 1 GHz in the excimer lamp lighting device according to the invention of the present embodiment, the applied voltage is compared with the case where high frequency power having a frequency of several tens of KHz is supplied. The conventional effect that can be reduced to a low voltage.

Next, a second embodiment of the present invention will be described with reference to FIGS.
FIG. 4 is a diagram showing the configuration of the excimer lamp lighting device according to the invention of this embodiment.
In the first embodiment of the present invention shown in FIG. 1, the excimer lighting device according to the present embodiment includes a timer circuit 30 instead of the logic circuit 4, the lighting detection means 8, and the lighting detection circuit 9 included in the control unit 10. It is provided. Other configurations correspond to the configurations of the same reference numerals shown in FIG.

  The timer circuit 30 starts the time counting operation simultaneously with receiving the start signal sent from the lighting switch circuit 1. Then, after counting a predetermined time set in advance, the timing is terminated and a gain control signal is sent to the amplifier means 5.

Next, the operation of the excimer lamp lighting device according to the present invention will be described with reference to timing charts shown in FIGS.
First, from the lighting switch circuit 1 of the control unit 10, a start signal, which is a lighting start command for the excimer lamp 7, is sent to the function generator 2 and the timer circuit 30 of the lighting circuit unit 20 (S111). The function generator 2 receives the start signal and sends a high-frequency sine wave signal to the amplifier means 5 (S112). The amplifier means 5 receives the high frequency sine wave signal from the function generator 2 and outputs high frequency power (S113). The output power is applied to the excimer lamp 7 via the matching circuit 6.

  Here, the electric power amplified and output by the amplifier means 5 has a voltage frequency of 1 MHz to 1 GHz, and in the excimer lamp 7, the discharge plasma reliably grows in the entire discharge space 118 in a short time. It is set to such a value.

  On the other hand, the timer circuit 30 starts the time counting operation at the same time as receiving the start signal from the lighting switch circuit 1. Then, after measuring a predetermined time, a gain control signal is sent to the amplifier means 5 (S114). The amplifier means 5 changes the amplification factor based on the gain control signal received from the timer circuit 30 and changes the value of the high-frequency power to be output (region to the right of the broken line in S113).

  Here, the predetermined time set in the timer circuit 30 is a period from when power is supplied to the excimer lamp to start the excimer lamp until discharge plasma is uniformly generated in the entire discharge space. This is a time corresponding to the excimer lamp start-up period, for example, 0.5 seconds.

  The power output from the amplifier means 5 with the amplification factor changed is steady power supplied when the excimer lamp 7 is steadily lit. This steady power is set so that, for example, an excimer light intensity required in an optical processing apparatus using excimer light can be obtained.

  Thus, also in the excimer lamp lighting device according to the invention of the present embodiment, the same effects as the excimer lamp lighting device according to the invention of the first embodiment can be achieved.

  In particular, in this embodiment, there is provided a timer means (timer circuit 30) that sends a signal after a lapse of a certain time from when power is supplied to the excimer lamp until discharge plasma is uniformly generated in the entire discharge space. Based on the signal from the timer means, the power supplied to the excimer lamp is switched from higher power to steady power than during steady lighting, so it is possible to reliably switch the power supplied to the excimer lamp. .

  Further, according to the present embodiment, since the timer circuit 30 is provided in place of the logic circuit 4, the detection means 8, and the lighting detection circuit 9 of the first embodiment, the configuration becomes simple and the apparatus can be downsized. Is possible.

  In this embodiment as well, as in the first embodiment, the sealing pressure of the discharge gas (for example, xenon) sealed in the discharge space of the excimer lamp is preferably 10 kPa or more at room temperature.

  In the above embodiment, the high-frequency high-voltage power supply 105 and the power feeding part 119 of the electrode 103 are formed at one end of the electrode, but the present invention is not limited to this, and can be provided at the center of a long electrode. . The advantage of forming the electrode at one end is that the electrode can be easily formed, and the advantage of providing it at the center of the electrode can shorten the growth time of the discharge plasma.

  In the present invention, in addition to enclosing xenon gas as the discharge gas for the excimer lamp, other gases can be encapsulated. The light having a single wavelength emitted from the excimer lamp is determined by the sealed gas in the discharge vessel. In the case of xenon gas (Xe), light having a wavelength of 172 nm, in the case of argon gas (Ar), the light having a wavelength of 126 nm, krypton gas. In the case of (Kr), light having a wavelength of 146 nm, in the case of a mixed gas of argon gas (Ar) and chlorine gas (Cl), in the case of a light of wavelength 175 nm, in the case of a mixed gas of krypton gas (Kr) and iodine gas (I) Light having a wavelength of 191 nm, light having a wavelength of 193 nm in the case of a mixed gas of argon gas (Ar) and fluorine gas (F), light having a wavelength of 207 nm in the case of a mixed gas of krypton gas (Kr) and iodine gas (I), krypton In the case of a mixed gas of gas (Kr) and chlorine gas (Cl), light having a wavelength of 222 nm is emitted.

It is a figure which shows the structure of the excimer lamp lighting device which concerns on invention of 1st Embodiment. It is a figure which shows the specific structural example of an excimer lamp. It is a figure which shows the timing chart of operation | movement of the excimer lamp lighting device which concerns on invention of 1st Embodiment. It is a figure which shows the structure of the excimer lamp lighting device which concerns on invention of 2nd Embodiment. It is a figure which shows the timing chart of operation | movement of the excimer lamp lighting device which concerns on invention of 2nd Embodiment. It is a figure which shows an example of the surface cleaning apparatus using an excimer lamp lighting device. It is a figure which shows the specific structural example of an excimer lamp. It is a figure explaining the process in which discharge plasma grows in the conventional excimer lamp.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lighting switch circuit 2 Function generator 4 Logic circuit 5 Amplifier means 6 Matching circuit 7 Excimer lamp 8, 81, 82 Lighting detection means 9 Lighting detection circuit 10 Control part 20 Lighting circuit part 30 Timer circuit

Claims (6)

An excimer lamp in which a discharge gas for generating excimer molecules by discharge is filled in a discharge vessel, a lighting circuit unit for turning on the excimer lamp by supplying high frequency power having a frequency of 1 MHz to 1 GHz to the excimer lamp, and a control unit In the excimer lamp lighting device consisting of
The control unit causes the excimer lamp to supply power higher than the steady power supplied when the excimer lamp is steadily lit during the start-up period of the excimer lamp. An excimer lamp lighting device that controls the lighting circuit unit so as to be supplied to an excimer lamp.   The control unit has lighting detection means for detecting that the excimer lamp has shifted to steady lighting, and the power supplied to the excimer lamp based on a signal from the lighting detection means is steady from higher power than that during steady lighting. The excimer lamp lighting device according to claim 1, wherein a command signal for commanding switching to electric power is sent to the lighting circuit unit.   The control unit has timer means for sending a signal after a predetermined time from the start of the excimer lamp, and the power supplied to the excimer lamp based on the signal from the timer means is changed from a higher power than the steady lighting to a steady power. 2. The excimer lamp lighting device according to claim 1, wherein a command signal instructing to switch to is sent to the lighting circuit section.   The fixed time is set so as to substantially coincide with a time until the excimer lamp is started when electric power higher than the normal power is supplied and the excimer lamp is started. Excimer lamp lighting device.   The excimer lamp lighting device according to any one of claims 1 to 4, wherein an enclosure pressure of the discharge gas is 10 kPa or more at room temperature. In an excimer lamp lighting method, a high frequency power having a frequency of 1 MHz to 1 GHz is supplied to an excimer lamp filled with a discharge gas that generates excimer molecules by discharge.
During the excimer lamp start-up period, power higher than the steady power supplied when the excimer lamp is steadily lit is supplied to the excimer lamp, and after the excimer lamp has shifted to the steady lit state, the steady power is supplied to the excimer lamp. Excimer lamp lighting method characterized by that.

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