JP2015119127A - Light irradiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light irradiation device capable of maintaining the atmosphere required in a processing chamber, thereby efficiently processing a processing object in a short period of time.SOLUTION: A light irradiation device has two spaces partitioned by a sealing member arranged on a light-transmissive window member and a peripheral portion of the light-transmissive window member. A lamp chamber is formed by one of the spaces, and a processing chamber is formed by the other space. The processing chamber is provided with processing gas supply means for supplying processing gas containing an active species source which generates an active species from ultraviolet light emitted from an ultraviolet radiation lamp. The lamp chamber is provided with lamp chamber atmospheric gas supply means for supplying lamp chamber atmospheric gas. When the light irradiation device is in operation, the internal pressure in the processing chamber is kept higher than that in the lamp chamber.

Description

  The present invention relates to a light irradiation apparatus. More specifically, the present invention relates to, for example, a photo-ashing process of a resist in a manufacturing process of a semiconductor or a liquid crystal, a removal of a resist adhering to a template pattern surface in a nanoimprint apparatus, or a dry cleaning process of a glass substrate or a silicon wafer for liquid crystal The present invention relates to a light irradiation apparatus suitable for smear removal (desmear) processing in a printed circuit board manufacturing process.

  Currently, for example, photo-ashing of resist in the manufacturing process of semiconductors, liquid crystals, etc., removal of resist adhering to the pattern surface of the template in the nanoimprint apparatus, or dry cleaning processing of glass substrates and silicon wafers for liquid crystals, printed circuit board manufacturing As a method for removing smear in the method, a dry cleaning method using ultraviolet rays is known.

As a certain kind of light irradiation apparatus for performing these processes, as shown in FIG. 3, the interior of the casing 71 is partitioned by a light-transmitting window member 31, thereby processing chamber S and lamp chamber. There is one in which R is formed (for example, see Patent Document 1). In the processing chamber S, a workpiece support base 18 for arranging the workpiece W is arranged, while in the lamp chamber R, an ultraviolet radiation lamp 28 such as an excimer lamp is arranged. The light transmissive window member 31 is made of a light transmissive material that transmits ultraviolet rays emitted from the ultraviolet radiation lamp 28, specifically, for example, quartz glass. The light irradiation apparatus includes a processing gas supply means for supplying a processing gas containing an active species source such as oxygen gas to the processing chamber S, and a non-exhaust gas such as nitrogen gas to the lamp chamber R. A lamp chamber atmosphere gas supply means for supplying an active gas is provided.
This light irradiation apparatus irradiates ultraviolet rays from an ultraviolet radiation lamp 28 through a light-transmitting window member 31 onto a surface Wa of a workpiece (workpiece) W disposed in an atmosphere of a processing gas. By doing so, the surface treatment of the workpiece W is performed using activated species (specifically, ozone gas and oxygen radicals) generated from the activated species source by ultraviolet rays.
In FIG. 3, the processing gas supply means and the lamp chamber atmosphere gas supply means are detected by the control unit 75 by a pressure sensor 77 that detects the internal pressure of the processing chamber S and a pressure sensor 77 that detects the internal pressure of the lamp chamber R. The gas supply conditions are determined based on the internal pressure.
Specifically, the processing gas supply means includes processing gas supply sources 82A, 82B, and 82C and a vacuum pump 83. The processing gas supply sources 82A, 82B, and 82C are connected to a gas supply through hole 72A formed in the housing 71 via a gas flow path forming member 81A. Further, in the gas flow path formed by the gas flow path forming member 81A, valves 84A, 84B, and 84C are provided between the processing gas supply sources 82A, 82B, and 82C and the gas supply through hole 72A. Yes. On the other hand, the vacuum pump 83 is connected to a gas discharge through hole 72B formed in the housing 71 via a gas flow path forming member 81B. Further, a valve 84D is provided between the vacuum pump 83 and the gas discharge through hole 72B in the gas flow path formed by the gas flow path forming member 81B. And in this process gas supply means, valve | bulb 84A, 84B, 84C, 84D is adjusted by the control part 75 according to gas supply conditions.
The lamp chamber atmosphere gas supply means includes a lamp chamber atmosphere gas supply source 86 and a vacuum pump 87. The lamp chamber atmosphere gas supply source 86 is connected to a gas supply through-hole 73A formed in the housing 71 via a gas flow path forming member 85A. Further, a valve 88A is provided between the lamp chamber atmosphere gas supply source 86 and the gas supply through hole 73A in the gas flow path formed by the gas flow path forming member 85A. On the other hand, the vacuum pump 87 is connected to a gas discharge through hole 73B formed in the housing 71 through a gas flow path forming member 85B. Further, a valve 88B is provided between the vacuum pump 87 and the gas discharge through hole 73B in the gas flow path formed by the gas flow path forming member 85B. In the lamp chamber atmosphere gas supply means, the valves 88A and 88B are adjusted by the controller 75 in accordance with the gas supply conditions.

Moreover, in such a light irradiation apparatus, the housing 71 is provided with a support portion for supporting the light-transmissive window member 31. Then, by arranging the light transmissive window member 31 on the support portion via a seal member, an airtight structure of the light transmissive window member 31 (hereinafter also referred to as “window member airtight structure”) is formed. ing. As the sealing member, a material having high ultraviolet resistance and, if necessary, ozone resistance is used.
As a specific example of the window member hermetic structure, for example, one having a configuration using an O-ring made of a fluororesin or a silicon resin as a sealing member can be cited. When an O-ring is used as the seal member, for example, as shown in FIG. 4, a support portion made of a metal such as aluminum or stainless steel that protrudes inwardly on the inner peripheral surface of the housing over the entire inner periphery. 92 is provided, and a concave portion 93 for arranging the seal member 91 is formed in the support portion 92. And the window member airtight structure is formed by arrange | positioning the light transmissive window member 31 on the sealing member 91 arrange | positioned at this recessed part 93, and pressing with the pressing member 94. FIG.

However, in the light irradiation apparatus having such a configuration, the ultraviolet light from the ultraviolet radiation lamp 28 is irradiated particularly when the light from the ultraviolet radiation lamp 28 includes ultraviolet light having a wavelength of 300 nm or less that particularly deteriorates resin or rubber. As a result, the seal member 91 may be deteriorated, and sufficient airtightness may not be obtained between the support portion 92 and the light transmissive window member 31. Further, when ultraviolet rays having a short wavelength of 220 nm or less are contained, ozone gas is generated from the activated species source contained in the processing gas, and therefore the seal member 91 is deteriorated by ozone gas, and light is transmitted through the support portion 92 and light. In some cases, sufficient airtightness may not be obtained between the conductive window member 31 and the conductive window member 31.
Further, as the seal member, a structure using a combination of an elastic member made of a polytetrafluoroethylene packing or a fluororesin soft sheet and a pure aluminum light shielding member (hereinafter also referred to as “combination member”) is used. There are also things. In this combination member, the elastic member mainly functions as an elastic material, and the light shielding member mainly has a light shielding function for suppressing the elastic member from being irradiated with light from the ultraviolet radiation lamp.

Further, in the light irradiation device, the thermal expansion coefficient of the metal constituting the support portion 92 of the light transmissive window member 31 is larger than the thermal expansion coefficient of the quartz glass constituting the light transmissive window member 31. Thus, there is also a problem that the intended processing cannot be efficiently performed on the workpiece W.
More specifically, the window member hermetic structure is designed in consideration of a difference in expansion coefficient between the support portion 92 and the light transmissive window member 31. That is, there is a portion where a slight gap 95 is formed between the support portion 92 and the light transmissive window member 31. For this reason, the support portion 92 and the light transmissive window member 31 are heated, for example, by being irradiated with light from the ultraviolet radiation lamp 28, so that the coefficient of thermal expansion is between the support portion 92 and the light transmissive window member 31. There is a possibility that relative displacement occurs due to the difference and sufficient airtightness cannot be obtained. That is, the airtightness of the processing chamber S and the lamp chamber R may not be maintained. In particular, when a combination member is used as the seal member 91, the combination member has a low sealing property between the support portion 92 and the light transmissive window member 31, and thus the support portion 92 and the light transmissive window member 31 There is a high possibility that sufficient airtightness cannot be obtained during this period.

As described above, sufficient airtightness cannot be obtained between the support portion 92 and the light transmissive window member 31, and as a result, the gas for the lamp chamber atmosphere flows from the lamp chamber R into the processing chamber S. When the lamp chamber atmosphere gas flows into the processing chamber S, the concentration of the active species source in the processing chamber S (specifically, for example, the oxygen gas concentration) decreases. In addition, in the processing chamber S, in order to perform processing with high uniformity and high efficiency on the processing surface Wa of the processing object W, the supply of processing gas from the processing gas supply means is relatively small. Since the gas flow rate, that is, a low gas flow rate is used, the concentration of the active species source greatly changes due to the inflow of the lamp chamber atmosphere gas. Therefore, since the amount of active species provided for the treatment is reduced, it takes more time to treat the workpiece W.
Such a problem becomes conspicuous in a light irradiation apparatus including a light-transmitting window member having a large area in which at least one of the vertical dimension and the horizontal dimension exceeds 400 mm. The reason is that a relative positional shift caused by a difference in thermal expansion coefficient between the support portion and the light transmissive window member becomes large.

JP 2003-144913 A

  The present invention has been made on the basis of the circumstances as described above, and the object thereof is to ensure the atmosphere required in the processing chamber, and therefore to efficiently process the object to be processed in a short time. It is in providing the light irradiation apparatus which can be used.

The light irradiation device of the present invention has two spaces formed by being partitioned by a light transmissive window member that transmits ultraviolet light from an ultraviolet radiation lamp and a seal member that is disposed at a peripheral portion of the light transmissive window member. Have
A lamp chamber in which the ultraviolet radiation lamp is disposed is formed by one of the two spaces, and ultraviolet light from the ultraviolet radiation lamp is irradiated through the light transmissive window member by the other space. A processing chamber in which workpieces are placed is formed,
A processing gas supply means for supplying a processing gas containing an active species source that generates active species by ultraviolet rays from the ultraviolet radiation lamp to the processing chamber, and a lamp chamber to the lamp chamber In a light irradiation apparatus provided with a lamp chamber atmosphere gas supply means for supplying an atmosphere gas,
During operation, the internal pressure of the processing chamber is maintained higher than the internal pressure of the lamp chamber.

  In the light irradiation apparatus of the present invention, the difference between the internal pressure of the processing chamber and the internal pressure of the lamp chamber is preferably 30 to 1000 Pa.

  According to the light irradiation apparatus of the present invention, since the internal pressure of the processing chamber is maintained higher than the internal pressure of the lamp chamber during the operation of the apparatus, the hermeticity of the processing chamber and the lamp chamber cannot be maintained. Even in this case, only the processing gas flows into the lamp chamber from the processing chamber, and the lamp chamber atmosphere gas does not flow into the processing chamber from the lamp chamber. Therefore, in the processing chamber, since the atmosphere is formed only by the processing gas supplied from the processing gas supply means, the concentration of the active species source is reduced due to the inflow of the lamp chamber atmosphere gas. Can be prevented. Therefore, since the atmosphere required in the processing chamber can be ensured, the object to be processed can be processed efficiently and in a short time.

It is sectional drawing for description which shows an example of a structure of the light irradiation apparatus of this invention. It is sectional drawing for description which shows the other example of a structure of the light irradiation apparatus of this invention. It is sectional drawing for description which shows an example of a structure of the conventional light irradiation apparatus. It is sectional drawing for description which shows an example of the airtight structure of the light transmissive window member in the conventional light irradiation apparatus.

  Embodiments of the present invention will be described below.

[First Embodiment]
FIG. 1 is an explanatory cross-sectional view showing an example of the configuration of the light irradiation apparatus of the present invention.
This light irradiation apparatus 10 includes a rectangular parallelepiped metal processing chamber housing 11 having an opening on the upper side and having a space for placing a workpiece (workpiece) W therein. . A light source unit 20 having a substantially rectangular parallelepiped outer shape is hermetically sealed on the processing chamber casing 11 by a rectangular annular processing chamber seal member 19 so as to close the opening of the processing chamber casing 11. Is provided. In this manner, a sealed processing chamber S is formed inside the processing chamber casing 11. That is, the processing chamber S is formed and sealed by the processing chamber casing 11, the processing chamber sealing member 19, and the light source unit 20.
In the example of this figure, the workpiece W has a rectangular flat plate shape, and the workpiece surface Wa of the workpiece is rectangular and has vertical and horizontal dimensions of 500 mm × 500 mm.
Further, in the processing chamber casing 11, a rectangular annular recess 14 is formed on a rectangular annular upper end surface 13a formed by the upper ends of the four side wall portions so as to surround the opening edge of the processing chamber casing 11. ing. A processing chamber seal member 19 made of a soft gasket such as an O-ring and a rubber sheet is disposed in the recess 14. The processing chamber seal member 19 is in pressure contact with the light source unit 20. Yes. Further, as the processing chamber seal member 19, the processing gas, the lamp chamber atmosphere gas, the active species generated by the ultraviolet rays, and the reaction product gas generated by processing the processing surface Wa of the workpiece W are processed. A highly resistant material is used.

The light source unit 20 includes a substantially rectangular parallelepiped metal lamp chamber housing 21 having an opening below. In the lamp chamber casing 21, the opening is formed in the center of the rectangular frame-shaped lower wall portion 25.
Further, a plurality of rod-shaped ultraviolet radiation lamps 28 are disposed in the lamp chamber housing 21. The plurality of ultraviolet radiation lamps 28 are arranged in parallel at regular intervals (equal intervals in FIG. 1) so that the central axes extend in parallel with each other in the same horizontal plane.
A light transmissive window member 31 is airtightly provided in the opening of the lamp chamber housing 21 by a support mechanism. In this way, a sealed lamp chamber R is formed inside the lamp chamber casing 21. Further, the lamp chamber R and the processing chamber S are partitioned by the light transmissive window member 31 and the lamp chamber sealing member 29, so that a plurality of ultraviolet radiation lamps 28 are disposed through the light transmissive window member 31. S is opposed to S.

The support mechanism sandwiches the peripheral portion of the light transmissive window member 31 through the rectangular annular lamp chamber sealing member 29 by the lower wall portion 25 of the lamp chamber casing 21 and the pressing member 26. In other words, the light transmissive window member 31 is airtightly supported by being sandwiched by the support mechanism via the lamp chamber seal member 29 disposed at the peripheral portion. In this way, an airtight structure of the light transmissive window member 31 is formed.
A rectangular annular recess 25A is formed on the lower surface of the lower wall portion 25 constituting the support mechanism so as to surround the opening edge of the lamp chamber casing 21, and a lamp chamber seal member 29 is disposed in the recess 25A. Has been.
The pressing member 26 has a rectangular frame-shaped pressing portion 26A having an opening having the same size as the opening of the lamp chamber housing 21 in the center, and a rectangular cylindrical shape provided on the outer peripheral edge of the pressing portion 26A. It is a metal thing which has the support part 26B. The pressing member 26 is disposed so as to press the light transmissive window member 31 through the lamp chamber sealing member 29, and thus the lamp chamber sealing member 29 is arranged at the periphery of the light transmissive window member 31. It is in a state of being in pressure contact with the upper surface of the part.
In the example of this figure, the lamp chamber sealing member 29 is shielded from light by the lower wall portion 25, so that direct light from the ultraviolet radiation lamp 28 is not irradiated.

The material constituting the light transmissive window member 31 is transmissive to ultraviolet rays emitted from the ultraviolet radiation lamp 28, and includes a processing gas, a lamp chamber atmosphere gas, active species generated by the ultraviolet rays, and an object to be processed. A material having resistance against a reaction product gas generated by processing the target surface Wa of W is used.
A specific example of the material constituting the light transmissive window member 31 is, for example, quartz glass.
The thickness of the light transmissive window member 31 is preferably 3 to 10 mm.
When the thickness of the light transmissive window member 31 is less than 3 mm, the light transmissive window member 31 may be greatly bent due to the difference between the internal pressure of the lamp chamber R and the internal pressure of the processing chamber S, and may be damaged due to the distortion. On the other hand, when the thickness of the light transmissive window member 31 exceeds 10 mm, the transmittance of ultraviolet rays decreases.
In the example of this figure, the light transmissive window member 31 has a rectangular flat plate shape, a vertical and horizontal dimension of 580 mm × 580 mm, and a thickness of 5 mm.

As the lamp chamber sealing member 29, for example, a soft gasket such as an O-ring and a rubber sheet is used.
The material constituting the lamp chamber sealing member 29 includes a processing gas, a lamp chamber atmosphere gas, active species generated by ultraviolet rays, and a reaction that occurs when the surface Wa of the workpiece W is processed. A material having high resistance to the generated gas and having high resistance to ultraviolet rays emitted from the ultraviolet radiation lamp 28 is used as necessary.
A specific example of the material constituting the lamp chamber sealing member 29 is, for example, fluororubber.
In the example of this figure, as the lamp chamber sealing member 29, an O-ring having an outer diameter of 4 mm made of fluororubber is used.

As the ultraviolet radiation lamp 28, various known lamps can be used as long as they emit ultraviolet light.
Specific examples of the ultraviolet radiation lamp 28 include a low-pressure mercury lamp that emits ultraviolet light having a wavelength of 185 nm and a wavelength of 254 nm, an excimer lamp that emits ultraviolet light having a central wavelength of 172 nm, and a high-pressure mercury lamp that emits ultraviolet light having a wavelength of 254 nm and 365 nm. Etc.
In the example of this figure, as the ultraviolet radiation lamp 28, a cylindrical excimer lamp that emits light including ultraviolet light having a center wavelength of 172 nm in a specific direction (downward direction in FIG. 1) is used. This excimer lamp has a light emission length of 700 mm, an outer diameter of 40 mm, and a rated power consumption of 500 W.

Further, the light source unit 20 is provided with a lamp chamber atmosphere gas supply means for supplying a lamp chamber atmosphere gas to the lamp chamber R.
Since the lamp chamber atmosphere gas supply means is provided, the ultraviolet radiation lamp 28 can be cooled by the supplied lamp chamber atmosphere gas. Therefore, even when the ultraviolet radiation lamp 28 is lit for a long time, the ultraviolet radiation lamp 28 can be controlled to an appropriate temperature.
In particular, when an ultraviolet radiation lamp that emits ultraviolet light having a wavelength of 220 nm or less (vacuum ultraviolet light) is used, an appropriate gas for the lamp chamber atmosphere (specifically, an inert gas such as nitrogen gas). ) Can be used effectively as the emitted light from the light source unit 20 from the ultraviolet radiation lamp 28. That is, in the lamp chamber housing 21, it is possible to prevent the vacuum ultraviolet rays from the ultraviolet radiation lamp 28 from being absorbed by the gas constituting the atmosphere in the lamp chamber housing 21.

The lamp chamber atmosphere gas supply means includes a lamp chamber atmosphere gas supply source (not shown), and a gas supply through hole 23 formed in the side wall portions 21A and 21C facing each other in the lamp chamber casing 21. In addition, the gas for the lamp chamber atmosphere is caused to flow into the lamp chamber R through the gas discharge through hole 24. The gas supply source for the lamp chamber atmosphere is connected to the gas supply through hole 23 via a gas flow path forming member, and a gas supply gas flow path formed by the gas flow path forming member includes a valve. (Not shown) is provided. Further, a gas flow path forming member is connected to the gas discharge through hole 24, and a valve (not shown) is provided in the discharge gas flow path formed by the gas flow path forming member. Yes.
In the lamp chamber atmosphere gas supply means, a valve disposed in the supply gas flow path is adjusted according to the lamp chamber atmosphere gas supply conditions. Further, based on the internal pressure difference measured by the differential pressure gauge between the lamp chamber R and the processing chamber S or the internal pressure detected by the pressure sensor disposed in each of the lamp chamber R and the processing chamber S, the exhaust gas The conductance of the flow path is adjusted. As a method for adjusting the conductance of the exhaust gas flow path, for example, a method of adjusting a valve provided in the exhaust gas flow path, a method of adjusting the diameter of the gas exhaust through-hole 24, and an exhaust gas flow Examples thereof include a method of adjusting the pipe diameter and pipe length of the gas flow path forming member that forms the path.

The lamp chamber atmosphere gas supplied from the lamp chamber atmosphere gas supply means to the lamp chamber R includes the type of the ultraviolet radiation lamp 28 and the wavelength range of the ultraviolet rays required for processing the workpiece W, that is, the light source. An inert gas such as nitrogen gas, air, or the like is used according to the wavelength range of ultraviolet rays required for the light emitted from the unit 20. Here, in the present specification, “air” includes a concept including air that has been treated such as air in the environmental atmosphere (air in the external atmosphere of the light source device 10) and low dew point high cleanliness air (CDA). It is. Specifically, when the emitted light from the light source unit 20 requires ultraviolet light having a wavelength of 220 nm or less, an inert gas is used. In addition, when the light emitted from the light source unit 20 requires ultraviolet light having a wavelength exceeding 220 nm, inert gas and low dew point high cleanliness air (CDA) can be used.
In the example of this figure, nitrogen gas is used as the lamp chamber atmosphere gas.

The gas supply condition for the lamp chamber atmosphere by the lamp chamber atmosphere gas supply means depends on the type of the ultraviolet radiation lamp 28, the number of the ultraviolet radiation lamps 28, etc., and the processing gas supply by the processing gas supply means. It is determined appropriately in consideration of conditions.
Then, by appropriately setting the lamp chamber atmosphere gas supply conditions, the ultraviolet radiation lamp 28 can be sufficiently cooled during the operation of the apparatus. Further, even when the processing gas flows into the lamp chamber R from the processing chamber S during the operation of the apparatus, the atmosphere of the lamp chamber R is used from the viewpoint of safety and effective use of the ultraviolet rays from the ultraviolet radiation lamp 28. The required atmospheric conditions can be met. Specifically, when the ultraviolet radiation lamp 28 that emits ultraviolet light having a wavelength of 220 nm or less is used, the atmosphere in the lamp chamber R is the required atmosphere in which the oxygen gas concentration is 1000 ppm or less and the ozone gas concentration is 1 ppm or less. The condition can be satisfied. In addition, when the ultraviolet radiation lamp 28 that emits only ultraviolet light having a wavelength exceeding 220 nm is used, the atmosphere of the lamp chamber R can satisfy the necessary atmospheric condition that the ozone gas concentration is 1 ppm or less. The reason why the ozone gas concentration is required to be 1 ppm or less is to reduce the absorption of ultraviolet rays by the lamp chamber atmosphere gas. Other reasons include preventing deterioration of the lamp constituent members of the ultraviolet radiation lamp 28 (specifically, external electrodes and external lead wires) due to oxidation, and a reflector ( This is for the purpose of preventing the deterioration of (not shown).
In the example of this figure, the lamp chamber atmosphere gas is supplied to the lamp chamber R by the lamp chamber atmosphere gas supply means under the lamp chamber atmosphere gas supply condition at a flow rate of 30 LPM.

In the processing chamber S, a processing object support 18 on which the processing object W is disposed is disposed so as to face the ultraviolet radiation lamp 28 through a light transmissive window member 31. The workpiece support table 18 has a workpiece mounting surface 18a that is a flat surface, and has larger vertical and horizontal dimensions than the workpiece surface Wa of the workpiece W.
An effective treatment region in which the treatment surface Wa can be treated with ultraviolet rays and active species (specifically, for example, ozone gas and oxygen radicals) is formed on the treatment object mounting surface 18a. And in this effective process area | region, the to-be-processed object W is arrange | positioned so that it may oppose in the state spaced apart from the transparent window member 31. FIG.
The distance between the workpiece W and the light transmissive window member 31 is appropriately determined according to the type of the ultraviolet radiation lamp 28. Specifically, when an ultraviolet radiation lamp 28 that emits ultraviolet light having a wavelength of 220 nm or less is used, it is preferably 3 mm or less, more preferably 0.1 to 1.0 mm. Moreover, when using what radiates | emits only the ultraviolet-ray over wavelength 220nm, it is preferable that it is 30 mm or less, Preferably it is 1-10 mm.
When the separation distance between the workpiece W and the light transmissive window member 31 is within the above range, the ultraviolet rays that reach the surface Wa to be processed can be set to a sufficiently large intensity (light quantity). Moreover, the active species can be stably generated from the active species source by ultraviolet rays.
In the example of this figure, the workpiece mounting surface 18a has a rectangular shape and has vertical and horizontal dimensions of 520 mm × 520 mm. The separation distance between the workpiece W and the light transmissive window member 31 is 0.7 mm.

Moreover, it is preferable that the workpiece support base 18 is provided with a heating means (not shown) for heating the workpiece W.
By providing the heating means on the workpiece support 18, the action of the active species can be promoted as the temperature of the surface Wa is increased, so that the treatment can be performed efficiently. it can.
Further, in the workpiece support table 18, the vertical and horizontal dimensions of the workpiece mounting surface 18a are larger than the vertical and horizontal dimensions of the workpiece surface Wa, so that the workpiece surface Wa can be heated uniformly.
The heating condition by the heating means is a condition in which the temperature of the workpiece placement surface 18a is, for example, 80 to 200 ° C.

Further, the light irradiation apparatus 10 is provided with a gas supply means for supplying a processing gas to the processing chamber S.
This processing gas supply means is provided with a processing gas supply source (not shown), a gas supply through-hole 15 formed in the side wall portions 11A and 11C facing each other in the processing chamber casing 11, and gas discharge. The processing gas is caused to flow into the processing chamber S through the through hole 16. The processing gas supply source is connected to the gas supply through hole 15 through a gas flow path forming member, and a valve (see FIG. Not shown). Further, a gas flow path forming member is connected to the gas discharge through hole 16, and a valve (not shown) is provided in the gas discharge gas flow path formed by the gas flow path forming member. ing.
The gas supply through-hole 15 has a horizontally long gas supply opening 15a disposed on the inner surface of the side wall portion 11A facing the processing chamber S along the direction in which the side wall portion 11A extends (direction perpendicular to the paper surface in FIG. 1). I have it. On the other hand, the gas discharge through-hole 16 is a horizontally long gas discharge opening disposed on the inner surface of the side wall portion 11C facing the processing chamber S along the direction in which the side wall portion 11C extends (direction perpendicular to the paper surface in FIG. 1). 16a. The gas discharge opening 16a is disposed opposite to the gas supply opening 15a.
Here, each of the gas supply opening 15a and the gas discharge opening 16a may be formed by one horizontally long slit or may be formed by a plurality of holes.
In the processing gas supply means, a valve disposed in the supply gas flow path is adjusted according to the processing gas supply conditions. In order to adjust the internal pressure of the processing chamber S in relation to the internal pressure of the lamp chamber R, the conductance of the exhaust gas flow path is adjusted. As a method for adjusting the conductance of the exhaust gas passage, for example, a method of adjusting a valve provided in the gas exhaust gas passage, a method of adjusting the diameter of the gas exhaust through-hole 16, and a gas exhaust Examples thereof include a method of adjusting the pipe diameter and pipe length of the gas flow path forming member that forms the gas flow path.
In the example of this figure, the gas supply opening 15a and the gas discharge opening 16a are formed by horizontally elongated slits extending over the entire area of the inner surface of the side portions 11A and 11C facing the workpiece support base 18.

As the processing gas supplied from the processing gas supply means to the processing chamber S, a gas containing an active species source that generates active species by ultraviolet rays from the ultraviolet radiation lamp 28 is used. Here, examples of the active species source include oxygen gas and ozone gas.
As the processing gas, when the light source unit 20 emits ultraviolet rays having a wavelength of 220 nm or less, for example, oxygen gas, a mixed gas of oxygen gas and ozone gas, or the like is used. Further, when the light source unit 20 emits ultraviolet rays having a wavelength exceeding 220 nm, for example, a mixed gas of oxygen gas and ozone gas is used from the viewpoint of shortening the processing time. The processing gas may contain water vapor.
In the example of this figure, oxygen gas is used as the processing gas, and this oxygen gas contains water vapor so that the humidity becomes 50 Rh%.

In the processing gas, the concentration of the active species source is preferably 70% by volume or more.
By setting the concentration of the active species source in the processing gas within the above range, the amount of active species generated by the ultraviolet rays can be increased, and the intended processing can be reliably performed.
Moreover, when using what contains ozone gas as processing gas, it is preferable that the density | concentration of ozone gas in processing gas is 12 volume% or less from a viewpoint of safety | security.

The processing gas supply condition by the processing gas supply means depends on the size of the processing surface Wa and the like, the type of the ultraviolet radiation lamp 28, the type of the processing object W, and the type of processing required for the processing surface Wa. It is determined as appropriate in consideration of the type and composition of the processing gas.
Then, by appropriately determining the processing gas supply conditions, it is possible to perform processing with high uniformity and high efficiency on the object to be processed.
In the example of this figure, the processing gas is supplied to the processing chamber S under the processing gas supply conditions with a flow rate of 1 LPM by the processing gas supply means.

During the operation of the light irradiation device 10, the internal pressure of the processing chamber S (differential pressure with respect to the atmosphere) is maintained higher than the internal pressure of the lamp chamber R.
Even when the internal pressure of the processing chamber S is maintained higher than the internal pressure of the lamp chamber R during the operation of the apparatus, the processing chamber S and the lamp chamber R can no longer maintain the airtightness. It is possible to prevent or suppress the flow of the lamp chamber atmosphere gas from the lamp chamber S into the chamber S.
In the example of this figure, the internal pressure of the processing chamber S is 100 Pa, and the internal pressure of the lamp chamber R is 60 Pa.

Further, the difference between the internal pressure of the processing chamber S and the internal pressure of the lamp chamber R is preferably 30 to 1000 Pa, more preferably 30 to 500 Pa, and particularly preferably 30 to 300 Pa.
When the difference between the internal pressure of the processing chamber S and the internal pressure of the lamp chamber R is excessively small, the processing chamber S can be used when the airtightness of the processing chamber S and the lamp chamber R cannot be maintained during the operation of the apparatus. The internal pressure of the lamp chamber R may not be maintained higher than the internal pressure of the lamp chamber R. On the other hand, when the difference between the internal pressure of the processing chamber S and the internal pressure of the lamp chamber R is excessive, the light transmissive window member 31 is bent, and as a result, the workpiece W and the light transmissive window are bent. Uniformity cannot be obtained in the thickness of the gap formed between the member 31 (the vertical dimension in FIG. 1), and therefore there is a possibility that the processing cannot be performed with high uniformity. Further, the light transmissive window member 31 may be damaged.
In the example of this figure, the difference between the internal pressure of the processing chamber S and the internal pressure of the lamp chamber R is 40 Pa.

  As a method for maintaining the internal pressure of the processing chamber S higher than the internal pressure of the lamp chamber R during the operation of the apparatus, there is a method of adjusting the conductance of the gas discharge gas flow path communicating with the lamp chamber R and the processing chamber S. Can be mentioned. Specifically, based on an internal pressure difference measured by a differential pressure gauge between the lamp chamber R and the processing chamber S, or an internal pressure detected by a pressure sensor disposed in each of the lamp chamber R and the processing chamber S, The gas discharge conditions in the lamp chamber R and the processing chamber S are adjusted so that the difference between the internal pressure of the lamp chamber R and the internal pressure of the processing chamber S falls within the intended range.

In the light irradiation apparatus 10 having such a configuration, ultraviolet rays from an ultraviolet radiation lamp (specifically, an excimer lamp that emits light including ultraviolet rays having a central wavelength of 172 nm) are arranged in an atmosphere of a processing gas. By irradiating the processed surface Wa of the processed object W through the light transmissive window member 31, the surface treatment of the processed object W is performed.
More specifically, the processing gas (specifically, oxygen gas) is supplied to the processing chamber S in which the workpiece W is disposed under the predetermined processing gas supply conditions via the gas supply opening 15a. Supplied. In this way, the processing gas is continuously supplied to the processing chamber S, and thereby the processing chamber S is set to the processing gas atmosphere. The lamp chamber R is supplied with lamp chamber atmosphere gas (specifically, nitrogen gas) from the lamp chamber atmosphere gas supply means under the desired lamp chamber atmosphere gas supply conditions. The gas atmosphere is assumed to be. Then, the plurality of ultraviolet radiation lamps 28 constituting the light source unit 20 are turned on all at once, so that the ultraviolet rays from the plurality of ultraviolet radiation lamps 28 are directed toward the surface Wa to be processed through the light transmissive window member 31. Irradiated. Thereby, the processing of the processing surface Wa is performed by the ultraviolet rays that reach the processing surface Wa and the active species (specifically, ozone gas and oxygen radicals) generated by the ultraviolet rays. In the processing chamber S, a reaction product gas (specifically, for example, carbon dioxide gas) generated by processing the surface Wa in the processing gas flowing through the processing chamber S is processed. Mixed with industrial gas. The gas mixed with the reaction product gas (hereinafter also referred to as “exhaust gas”) is discharged outside the processing chamber S through the gas discharge opening 16a.

During the operation of the light irradiation device 10, a difference in thermal expansion occurs between the light transmissive window member 31 and the members constituting the support mechanism (specifically, the lower wall portion 25 and the pressing member 26). As a result, a relative displacement may occur, and the lamp chamber seal member 29 may be deteriorated by ultraviolet rays, so that sufficient airtightness may not be obtained. In such a case, the light-transmitting window member 31 and the lamp chamber sealing member 29 are partitioned by a slight gap generated between the light-transmitting member 31 and the member constituting the support mechanism. The processing chamber S and the lamp chamber R which have been in communication with each other are brought into communication.
However, in the light irradiation apparatus 10, since the internal pressure of the processing chamber S is maintained higher than the internal pressure of the lamp chamber during the operation of the apparatus, only the processing gas flows from the processing chamber S into the lamp chamber R. The lamp chamber atmosphere gas does not flow into the processing chamber S from the lamp chamber R. Therefore, in the processing chamber S, since the atmosphere is formed only by the processing gas supplied from the processing gas supply means, the concentration of the active species source is reduced due to the inflow of the lamp chamber atmospheric gas. Can be prevented.
Moreover, in the lamp chamber R, the lamp chamber atmosphere gas flows at a large gas flow rate by determining the lamp chamber atmosphere gas supply conditions within the range required for the processing. Even when the working gas flows in, the processing gas that flows in by the gas flow of the lamp chamber atmosphere gas can be discharged. As a result, the atmosphere of the lamp chamber R can satisfy the atmospheric conditions required from the viewpoint of safety and effective use of the ultraviolet rays from the ultraviolet radiation lamp 28.
Therefore, according to the light irradiation apparatus 10, since the atmosphere required in the processing chamber S can be secured, the surface Wa to be processed can be processed efficiently in a short time.

  Moreover, in the light irradiation apparatus 10, the internal pressure of the processing chamber S is reliably kept higher than the internal pressure of the lamp chamber R by setting the difference between the internal pressure of the processing chamber S and the internal pressure of the lamp chamber R to 30 to 1000 Pa. be able to. Further, the difference between the internal pressure of the processing chamber S and the internal pressure of the lamp chamber R causes the light transmissive window member 31 to bend, and as a result, the desired processing cannot be performed, or the light transmissive window member. There is no adverse effect that 31 is broken.

  This light irradiation apparatus 10 is, for example, a photo ashing process of resist in a manufacturing process of semiconductors, liquid crystals, etc., removal of a resist adhering to a pattern surface of a template in a nanoimprint apparatus, or a dry cleaning process of a glass substrate for liquid crystal or a silicon wafer. It is suitably used for smear removal (desmear) treatment in a printed circuit board manufacturing process.

[Second Embodiment]
FIG. 2 is an explanatory sectional view showing another example of the configuration of the light irradiation apparatus of the present invention.
The light irradiation device 40 has the same configuration as the light irradiation device 10 of FIG. 1 except that the configuration of the light source unit 50 is different. In the light source unit 50, the interior space of the lamp chamber housing 21 is vertically divided, the concave reflecting mirror 58 is disposed inside the lamp chamber housing 21, and the lamp chamber atmosphere gas. The supply unit has the same configuration as that of the light source unit 20 according to the light irradiation apparatus 10 of FIG. 1 except that the supply unit circulates the gas for the lamp chamber atmosphere.
In the example of this figure, as the ultraviolet radiation lamp 28, a cylindrical high-pressure mercury lamp that emits light including ultraviolet light having a wavelength of 254 nm and a wavelength of 364 nm is used. This high-pressure mercury lamp has a light emission length of 600 mm, an outer diameter of 25 mm, and a rated power consumption of 10 kW.
Further, as the lamp chamber atmosphere gas, environmental atmosphere air is used.
In addition, a mixed gas of oxygen gas and ozone gas is used as the processing gas, and in this mixed gas, the oxygen gas concentration is 90% by volume and the ozone gas concentration is 10% by volume. This processing gas may contain water vapor so that the humidity becomes 50% Rh.

In the light source unit 50, the lamp chamber casing 21 includes a rectangular parallelepiped box-shaped lower space forming member 51 having an opening below, and a rectangular parallelepiped having an opening below disposed on the lower space forming member 51. The box-shaped upper space forming member 54 is integrally joined. Here, the opening of the lamp chamber housing 21 is formed at the center of the lower wall portion 25 of the rectangular frame shape in the lower space forming member 51. In the lamp chamber housing 21, an intake chamber I is formed by a space located above the upper wall portion 51A of the lower space forming member 51, and a space located below the upper wall portion 51A. As a result, a lamp chamber R is formed. In addition, a plurality of gas circulation ports 52 formed of slits are formed in the upper wall portion 51A of the lower space forming member 51, and the gas circulation ports 52 arranged at regular intervals (equal intervals in FIG. 2). The intake chamber I and the lamp chamber R are in communication with each other.
In the lamp chamber R, a plurality of bar-shaped ultraviolet radiation lamps 28 are arranged in parallel at regular intervals (equal intervals in FIG. 2) so that the central axes extend in parallel with each other in the same horizontal plane, and the light transmissive window member 31 is arranged. It is set as the state which opposed the process chamber S through. Each of the plurality of ultraviolet radiation lamps 28 surrounds the ultraviolet radiation lamp 28 and emits light emitted from the ultraviolet radiation lamp 28 in a direction other than the direction toward the light transmissive window member 31. A concave reflecting mirror 58 that reflects toward the member 31 is provided.
In the example of this figure, the slit constituting the gas flow port 52 has a rectangular shape extending in the tube axis direction of the ultraviolet radiation lamp 28.

Further, in the light source unit 50, the lamp chamber atmosphere gas supply means includes a gas flow path forming member 61 having a tube structure having a branch pipe 62, and one end of the gas flow path forming member 61 is an upper space forming member 54. Is connected to a gas inlet 53 formed in the upper wall portion 54A. A plurality (three in FIG. 2) of branch pipes 62 penetrates the upper wall portion 54A of the upper space forming member 54 and the upper wall portion 51A of the lower space forming member 51 in an airtight manner. The other ends of the gas flow path forming members 61 related to the plurality of branch pipes 62 are each connected to a gas exhaust port 59 formed at the proximal end portion of the concave reflecting mirror 58. In this way, the gas flow path formed by the gas flow path forming member 61 communicates with the intake chamber I at one end and communicates with the lamp chamber R at the other end. Further, an ozone removing means 67 made of, for example, an ozone filter, a cooling means 66 made of, for example, a radiator, and an air blowing means 65 made of, for example, a blower are provided in a region from the branch portion 61a to the gas inlet 53 in the gas flow path. It is provided in order. Further, in the region from the gas exhaust port 59 to the branch portion 61a in the gas flow path, that is, in the branch pipe 62, a flow rate adjusting means 68 made of, for example, a damper is provided.
The lamp chamber atmosphere gas supply means circulates the lamp chamber atmosphere gas in the lamp chamber R through the gas flow ports 52 in the intake chamber I and the upper wall portion 51A of the lower space forming member 51. Then, the circulation condition of the lamp chamber atmosphere gas, that is, the supply condition of the lamp chamber atmosphere gas to the lamp chamber R is appropriately determined by adjusting the blowing means 65 and the flow rate adjusting means 68. Further, the temperature of the lamp chamber atmosphere gas supplied to the lamp chamber R is adjusted by the cooling means 66 and ozone in the process of flowing through the region from the branch portion 61a to the gas inlet 53 in the gas flow path. The ozone gas is removed by the removing means 67.
In the example of this figure, a radiator is used as the cooling means 66, and its cooling capacity is 15 kW. Further, the flow direction of the lamp chamber atmosphere gas is indicated by an arrow.

The gas supply conditions by the gas supply means for the lamp chamber atmosphere take into account the type of the processing gas and the gas supply conditions by the processing gas supply means according to the type of the ultraviolet radiation lamp 28 and the number of the ultraviolet radiation lamps 28. It is determined as appropriate.
Then, by appropriately setting the lamp chamber atmosphere gas supply conditions, the ultraviolet radiation lamp 28 can be sufficiently cooled during the operation of the apparatus. Further, even when the processing gas flows into the lamp chamber R from the processing chamber S during the operation of the apparatus, the atmosphere of the lamp chamber R is used from the viewpoint of safety and effective use of the ultraviolet rays from the ultraviolet radiation lamp 28. The required atmospheric conditions can be met.
In the example of this figure, the lamp chamber atmosphere gas is supplied to the lamp chamber R by the lamp chamber atmosphere gas supply means under the lamp chamber atmosphere gas supply conditions at a flow rate of 30 m ³ / min.

During the operation of the light irradiation device 40, the internal pressure of the processing chamber S is maintained higher than the internal pressure of the lamp chamber R.
Further, the difference between the internal pressure of the processing chamber S and the internal pressure of the lamp chamber R is preferably 30 to 1000 Pa, more preferably 30 to 500 Pa, and particularly preferably 30 to 300 Pa.
By setting the difference between the internal pressure of the processing chamber S and the internal pressure of the lamp chamber R to 30 to 1000 Pa, the internal pressure of the processing chamber S can be reliably kept higher than the internal pressure of the lamp chamber R. Further, the difference between the internal pressure of the processing chamber S and the internal pressure of the lamp chamber R causes the light transmissive window member 31 to bend, and as a result, the processing cannot be performed with high uniformity, or the light transmissive window. There is no problem that the member 31 is damaged.
In the example of this figure, the internal pressure of the processing chamber S is 500 Pa, the internal pressure of the lamp chamber R is 300 Pa, and the difference between the internal pressure of the processing chamber S and the internal pressure of the lamp chamber R is 200 Pa.

As a method for maintaining the internal pressure of the processing chamber S higher than the internal pressure of the lamp chamber R during the operation of the apparatus, conductance of the gas discharge gas flow path communicating with the processing chamber S, and the gas flow path forming member 61 A method for adjusting the conductance on the gas exhaust port 59 side is mentioned. Specifically, based on an internal pressure difference measured by a differential pressure gauge between the lamp chamber R and the processing chamber S, or an internal pressure detected by a pressure sensor disposed in each of the lamp chamber R and the processing chamber S, The gas discharge conditions in the lamp chamber R and the processing chamber S are adjusted so that the difference between the internal pressure of the lamp chamber R and the internal pressure of the processing chamber S falls within the intended range.
Here, as a method of adjusting the conductance of the gas flow path forming member 61 on the gas exhaust port 59 side, a method of adjusting the flow rate adjusting means 68 and the like can be mentioned.

In the light irradiation apparatus 40 having such a configuration, ultraviolet rays from an ultraviolet radiation lamp (specifically, a high-pressure mercury lamp that emits ultraviolet rays having a wavelength of 254 nm and a wavelength of 365 nm) 28 are arranged in an atmosphere of a processing gas. Surface treatment of the workpiece W is performed by irradiating the workpiece surface Wa of the workpiece W through the light transmissive window member 31.
More specifically, the processing gas (mixed gas of oxygen gas and ozone gas) is supplied to the processing chamber S in which the workpiece W is disposed through the gas supply opening 15a. Supplied in. In this way, the processing gas is continuously supplied to the processing chamber S, and thereby the processing chamber S is set to the processing gas atmosphere. Further, in the lamp chamber R, the lamp chamber atmosphere gas (specifically, air in an environmental atmosphere) is circulated by the lamp chamber atmosphere gas supply means, so that the lamp chamber atmosphere gas supply condition is satisfied. Lamp room atmosphere gas is supplied. Then, the plurality of ultraviolet radiation lamps 28 constituting the light source unit 50 are turned on at the same time, so that the ultraviolet rays from the plurality of ultraviolet radiation lamps 28 are directed toward the surface Wa through the light transmissive window member 31. Irradiated. As a result, the surface Wa is treated by the ultraviolet rays that reach the surface Wa and the active species (specifically, oxygen radicals) generated by the ultraviolet rays. In the processing chamber S, a reaction product gas (specifically, for example, carbon dioxide gas) generated by processing the surface Wa in the processing gas flowing through the processing chamber S is processed. Mixed with industrial gas. The exhaust gas mixed with the reaction product gas is discharged outside the processing chamber S through the gas discharge opening 16a.
In the example of this figure, the separation distance between the workpiece W and the light transmissive window member 31 is 2 mm.

Thus, according to the light irradiation device 40, the same effect as the light irradiation device 10 of FIG. 1 can be obtained. That is, according to the light irradiation apparatus 40, since the atmosphere required in the processing chamber S can be ensured, the surface Wa to be processed can be processed efficiently and in a short time.
This light irradiator 40 is similar to the light irradiator 10 of FIG. 1, for example, photo-ashing resist in the manufacturing process of semiconductors, liquid crystals, etc., removing resist adhered to the pattern surface of the template in the nanoimprint apparatus, It is suitably used for dry cleaning processing of glass substrates and silicon wafers, and smear removal (desmear) processing in printed circuit board manufacturing processes.

The light irradiation apparatus of the present invention is not limited to the above embodiment, and various modifications can be made.
For example, in the light irradiation apparatus according to the second embodiment, the lamp chamber atmosphere gas supply means does not circulate the lamp chamber atmosphere gas in the lamp chamber but includes a lamp chamber atmosphere gas supply source. In addition, the lamp chamber housing may be provided with a gas supply through hole and a gas discharge through hole. Specifically, the lamp chamber atmosphere gas supply means and the lamp chamber housing have the same configuration as the lamp chamber atmosphere gas supply means and the lamp chamber housing in the light irradiation apparatus 10 according to the first embodiment, for example. You may have. In this case, low dew point highly purified air or inert gas may be used as the lamp chamber atmosphere gas.

DESCRIPTION OF SYMBOLS 10 Light irradiation apparatus 11 Processing chamber housing | casing 11A, 11C Side wall part 13a Upper end surface 14 Recessed part 15 Gas supply through-hole 15a Gas supply opening 16 Gas discharge through-hole 16a Gas discharge opening 18 To-be-processed object support stand 18a Object placement surface 19 Processing chamber seal member 20 Light source unit 21 Lamp chamber housings 21A, 21C Side wall portion 23 Gas supply through hole 24 Gas discharge through hole 25 Lower wall portion 25A Recess 26 Press member 26A Press portion 26B Support portion 28 Ultraviolet radiation lamp 29 Lamp chamber sealing member 31 Light transmissive window member 40 Light irradiation device 50 Light source unit 51 Lower space forming member 51A Upper wall portion 52 Gas flow port 53 Gas inlet port 54 Upper space forming member 54A Upper wall portion 58 Concave reflecting mirror 59 Gas exhaust port 61 Gas flow path forming member 61a Branching portion 62 Branching tube 65 Blowing means 66 Cooling means 67 Ozone removing means 68 Flow rate adjusting means 71 Housing 72A Gas supply through-hole 72B Gas discharge through-hole 73A Gas supply through-hole 73B Gas discharge through-hole 75 Control section 76, 77 Pressure sensor 81A, 81B Gas flow path forming member 82A, 82B, 82C Processing gas supply source 83 Vacuum pumps 84A, 84B, 84C, 84D Valves 85A, 85B Gas flow path forming member 86 Lamp chamber atmosphere gas supply source 87 Vacuum pumps 88A, 88B Valve 91 Seal member 92 Support section 93 Concave portion 94 Holding member 95 Gap

Claims (2)

A light-transmitting window member that transmits ultraviolet light from the ultraviolet radiation lamp and two spaces formed by being partitioned by a seal member disposed at a peripheral portion of the light-transmitting window member;
A lamp chamber in which the ultraviolet radiation lamp is disposed is formed by one of the two spaces, and ultraviolet light from the ultraviolet radiation lamp is irradiated through the light transmissive window member by the other space. A processing chamber in which workpieces are placed is formed,
A processing gas supply means for supplying a processing gas containing an active species source that generates active species by ultraviolet rays from the ultraviolet radiation lamp to the processing chamber, and a lamp chamber to the lamp chamber In a light irradiation apparatus provided with a lamp chamber atmosphere gas supply means for supplying an atmosphere gas,
During the operation, the light irradiation apparatus is characterized in that an internal pressure of the processing chamber is maintained higher than an internal pressure of the lamp chamber. The light irradiation apparatus according to claim 1, wherein a difference between an internal pressure of the processing chamber and an internal pressure of the lamp chamber is 30 to 1000 Pa.

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