JP2011114001A - Exposure apparatus and device manufacturing method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exposure apparatus that efficiently prevents thermal deformation of a mirror in a mirror inside a projection optical system and suppresses fluctuations in the exposure light near a surface of the mirror so as to attain stable image performance. <P>SOLUTION: The exposure apparatus has a projection optical system, including a circular mirror 13 for reflecting exposure light, and a gas supply apparatus 14 for controlling the temperature of the circular mirror 13. The circular mirror 13 has an arcuate irradiation region 17; the gas supply apparatus 14 includes an air-blowing part 19 located in the central region on the surface of the circular mirror 13, while avoiding the irradiation region 17; the air-blowing part 19 is formed of a cylindrical member whose face facing the surface of the circular mirror 13 is closed; and temperature control air 18 is supplied radially, from the entire surface of the side face of the cylindrical member toward the outer-peripheral region of the circular mirror 13 so as to be along on the surface of the circular mirror 13. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an exposure apparatus and a device manufacturing method using the same.

  In a lithography process, which is a manufacturing process for semiconductor devices, liquid crystal display devices, and the like, an exposure apparatus uses a pattern of an original (reticle or mask) as a photosensitive substrate (a resist layer is formed on the surface) via a projection optical system. A transfer device to a wafer, a glass plate, or the like). For example, an exposure apparatus used for manufacturing a liquid crystal display device has a projection optical system including a plurality of mirrors for reflecting exposure light and irradiating the substrate to be processed. However, when this exposure apparatus is operated for a long time, the mirror in the projection optical system may be thermally deformed due to absorption of exposure heat. Therefore, as a method for suppressing thermal deformation of the mirror due to absorption of exposure heat, for example, Patent Document 1 includes a cooling mechanism having a nozzle that ejects a cooling medium to the mirror, and is not performing an exposure operation. An exposure apparatus for cooling the mirror surface is disclosed.

JP 2004-39905 A

  However, since the exposure apparatus shown in Patent Document 1 is a local cooling method in which a cooling medium is ejected from a nozzle, it is difficult to uniformly adjust the temperature of the exposure light irradiation region on the mirror. As a result, there is a possibility that thermal deformation occurs in a local part of the mirror and deteriorates the exposure performance. Further, in the exposure apparatus, there is a possibility that the cooling medium ejected from the nozzle entrains ambient air and disturbs the temperature environment of the atmosphere near the mirror. In this case, the exposure light fluctuates in the atmosphere near the mirror, and as a result, the exposure performance deteriorates.

  The present invention has been made in view of such a situation, and in the mirror in the projection optical system, the thermal deformation of the mirror is efficiently reduced, and the fluctuation of the exposure light near the surface of the mirror is reduced. An object of the present invention is to provide an exposure apparatus capable of obtaining stable image performance.

  In order to solve the above problems, an exposure apparatus having a projection optical system comprising a circular mirror that reflects exposure light and a gas supply device that controls the temperature of the circular mirror, the circular mirror having an arcuate irradiation The gas supply device includes a blower unit located in a central region of the surface of the circular mirror while avoiding the irradiation region, and the blower unit is a cylindrical member whose surface facing the surface of the circular mirror is blocked The temperature controlled air is supplied radially from the entire side surface of the cylindrical member toward the outer peripheral region of the circular mirror so as to extend along the surface of the circular mirror.

  According to the present invention, since the temperature of the circular mirror can be uniformly controlled, thermal deformation of the circular mirror is reduced, and fluctuation of exposure light near the surface of the circular mirror is reduced, thereby obtaining stable image performance. An exposure apparatus capable of performing the above can be provided.

It is the schematic which shows the structure of the exposure apparatus which concerns on embodiment of this invention. It is the schematic which shows the structure of the gas supply apparatus which concerns on 1st Embodiment of this invention. It is the schematic which shows the structure of the gas supply apparatus which concerns on 2nd Embodiment of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(First embodiment)
First, the configuration of the exposure apparatus according to the first embodiment of the present invention will be described. The exposure apparatus of the present invention is an apparatus that exposes a mask (original) pattern onto a glass plate (substrate) as a substrate to be processed by a step-and-scan method or a step-and-repeat method. In the present invention, the exposure method is not particularly limited. The exposure apparatus 1 first includes an exposure unit 3 that is an exposure apparatus main body housed in a constant temperature chamber 2 and an illumination optical system 4 that irradiates the exposure unit 3 with exposure light. The constant temperature chamber 2 includes an air conditioning machine room 5 and an air conditioning air supply unit 6, and is a device for keeping the surrounding environment surrounding the exposure unit 3 constant. The exposure unit 3 includes an imaging optical system 7 that converts exposure light from the illumination optical system 4 into a predetermined light beam, an original stage 8 that holds a mask on which a pattern is formed, a projection optical system 9, and a photosensitive agent. And a substrate stage 10 for positioning the coated glass plate. The projection optical system 9 is for reducing and projecting a mask pattern onto a glass plate at a predetermined magnification. The projection optical system 9 includes a trapezoidal mirror 11 that reflects exposure light, a convex mirror 12, a circular (concave) mirror 13, and a gas supply device 14 for supplying temperature-controlled air to the circular mirror 13. With. The mask stage 8 and the projection optical system 9 are both supported by the frame 15.

  Next, an outline of the exposure processing by the exposure apparatus 1 of the present embodiment will be described. First, the illumination optical system 4 introduces illumination light from a light source (discharge lamp such as an ultra-high pressure mercury lamp) 16 and converts it into a predetermined light beam by the imaging optical system 7, and then moves the mask on the original stage 8 upward. Illuminate from. Next, the pattern on the illuminated mask exposes the resist applied to the surface of the glass plate on the substrate stage 10 by the projection optical system 9 and performs an exposure process.

  Next, the configuration of the gas supply device 14 that is a feature of the present invention will be described. FIG. 2 is a schematic view showing the configuration of the gas supply device 14 according to the present embodiment, FIG. 2 (a) is a plan view including the circular mirror 13, and FIG. 2 (b) is a plan view of FIG. Is a cross-sectional view corresponding to FIG. As shown in FIG. 2A, the gas supply device 14 is a means for supplying temperature-controlled air 18 installed in the vicinity of the surface of the circular mirror 13 while avoiding the arc-shaped irradiation region 17 of the exposure light. The gas supply device 14 includes a blower 19 positioned at the center of the surface of the circular mirror 13, a supply path 20 that supplies the temperature-controlled air 18 to the blower 19, and an air guide 21 that collects the temperature-controlled air 18. And a temperature control unit (not shown) that adjusts the temperature of the temperature control air 18.

  The blower unit 19 is a blower unit that is located in the central region of the surface of the circular mirror 13 and is formed of a cylindrical member while closing the surface side of the circular mirror 13 with the rectifying plate 22. The blower unit 19 includes a rectifying filter 23 for uniformly blowing the temperature-controlled air 18 radially from the center of the circular mirror 13 toward the outer peripheral region over the entire cylindrical side surface. As the rectifying filter 23, a dust removing filter such as a ULPA filter or a thin mesh filter can be employed. In this case, the dust removal filter is excellent in the uniformity of the wind speed, while the mesh filter is excellent in space saving. In addition, it may replace with the rectification filter 23 and the structure which employ | adopts the plate in which several holes, such as punching metal, were penetrated may be used. As shown in FIG. 2B, the rectifying plate 22 desirably has a conical shape so that the temperature-controlled air 18 flows appropriately along the surface of the circular mirror 13.

  The supply path 20 is connected to an air supply device (not shown), and is a pipe line having two paths facing each other in order to supply the temperature-controlled air 18 uniformly to the blower unit 19. However, the pipe line may be a circular pipe or may have a rectangular cross section, and is not particularly limited. Further, it is desirable that both ends of the supply path 20 are fixed via vibration isolation members 24 such as anti-vibration rubber so that vibration is not transmitted to the circular mirror 13.

  The air guide unit 21 is a means for collecting the temperature-controlled air 18 installed so as to surround the side surface and the bottom surface of the circular mirror 13. In this case, in the vicinity of the side surface of the circular mirror 13 in the air guide portion 21, a recovery port 28 for efficiently recovering the temperature-controlled air 18 flowing along the surface of the circular mirror 13 over the entire outer peripheral portion. Is provided. Further, an exhaust passage 25 for collecting the temperature-controlled air 18 in the air supply device is provided near the bottom of the circular mirror 13 in the air guide portion 21.

  The temperature adjustment control unit is connected to the air supply device, and measures and controls the temperature of the temperature adjustment air 18 based on a predetermined set temperature and the value of the temperature sensor 26 installed in the blower unit 19. It is. As the temperature sensor 26, it is desirable to employ a sensor having a quick response such as a thermocouple. 2B, at least one temperature sensor 27 is installed on the outer periphery of the circular mirror 13, thereby measuring the temperature of the circular mirror 13 itself and controlling the temperature of the temperature control air 18. You may carry out. Further, in this case, the temperature control unit may change the supply amount of the temperature control air 18 so that the value of the temperature sensor 27 becomes a predetermined value, and uniformize the temperature of the circular mirror 13. Thereby, when the temperature rise of the circular mirror 13 is small, such as during non-exposure, it is possible to take measures such as reducing the supply amount of the temperature control air 18, which contributes to energy saving. The temperature sensor 27 in this case is not limited to a contact type such as a thermistor or a thermocouple, and a non-contact type radiation thermometer or the like can also be employed.

  Next, the operation and effect of the gas supply device 14 will be described. In general, the surface of the circular mirror 13 is coated with various films in order to obtain predetermined exposure performance. When the circular mirror 13 reflects exposure light, the circular mirror 13 absorbs part of the exposure light by the film and generates heat. Due to this heat generation, the circular mirror 13 is thermally deformed due to heat being transmitted to the inside, and further, the air in the vicinity space is warmed, thereby causing a refraction change of the air. Therefore, the gas supply device 14 of this embodiment controls the temperature of the circular mirror 13 by supplying the rectified temperature control air 18 along the surface of the circular mirror 13. In the exposure apparatus for the glass plate as in the present embodiment, the exposure light is cut out in an arc shape in order to obtain predetermined exposure performance from the circular exposure light. When the arc-shaped exposure light is irradiated onto the circular mirror 13 as described above, uniform temperature control is required for the arc-shaped irradiation region 17 as shown in FIG. Therefore, the gas supply device 14 further supplies the temperature control air 18 radially from the center of the arc in the radial direction, so that the temperature of the circular mirror 13 can be uniformly and efficiently controlled.

  Moreover, since the gas supply apparatus 14 is provided with the rectifying filter 23 in the ventilation part 19, and supplies the temperature control air 18 which removed dust, it prevents that the dust which exists in an atmosphere adheres to a reflective surface, Deterioration of exposure performance due to contamination can be suppressed. Further, the gas supply device 14 includes an air guide portion 21 that surrounds the circular mirror 13, and collects the temperature-controlled air 18 that has flowed on the surface of the circular mirror 13. The temperature can be adjusted efficiently.

  As described above, according to the exposure apparatus 1 of the present invention, fluctuation of exposure light is prevented by preventing thermal deformation of the circular mirror 13 and reducing air pressure change and temperature change in the vicinity of the surface of the circular mirror 13. By suppressing the above, stable image performance can be obtained.

(Second Embodiment)
Next, the configuration of an exposure apparatus according to the second embodiment of the present invention will be described. FIG. 3 is a schematic view showing the configuration of the gas supply device in the exposure apparatus according to the second embodiment, and is a cross-sectional view corresponding to the gas supply device 14 of FIG. In FIG. 3, the same components as those in FIG. 2 are denoted by the same reference numerals, and description thereof is omitted. The gas supply device 30 of the present embodiment is characterized in that the blower unit 19 includes a blower fan 31, a chemical filter 32, and a heat exchanger 33 instead of the supply path 20. The blower fan 31 is a blower unit that takes in atmospheric air and supplies it to the circular mirror 13. As the blower fan 31, a fan that controls the fan rotation speed by inverter control and changes the blower amount is desirable. The chemical filter 32 is a filter installed on the primary side of the blower fan 31 and removes chemical components in the air taken in by the blower fan 31 to clean the air. As the chemical filter 32, an ion exchange type that removes acid gas, alkaline gas, or the like, an activated carbon filter that removes organic gas, or the like can be adopted, and may be used properly according to the situation. Since the chemical filter 32 can prevent the chemical component from adhering to the surface of the circular mirror 13, the deterioration of the exposure performance due to fogging of the reflecting surface can be suppressed. Further, the heat exchanger 33 is heat exchange means installed on the secondary side of the blower fan 31 and processes heat generated by the blower fan 31 itself and regulates the temperature of the air taken in. In this case, the refrigerant for the heat exchanger 33 is supplied through the support member 34 that supports the blower unit 19. Further, the temperature adjustment in this case is performed by changing the flow rate of the refrigerant based on a certain predetermined set temperature and the value of the temperature sensor 26. In the gas supply device 30 of this embodiment, the temperature of the circular mirror 13 is also controlled by controlling the rotation speed of the blower fan 31 and changing the amount of the temperature-controlled air 18 based on the value of the temperature sensor 27. It may be made uniform. With these configurations, the same effects as those of the first embodiment can be obtained.

(Device manufacturing method)
Next, a method for manufacturing a device (semiconductor device, liquid crystal display device, etc.) according to an embodiment of the present invention will be described. A semiconductor device is manufactured through a pre-process for producing an integrated circuit on a wafer and a post-process for completing an integrated circuit chip on the wafer produced in the pre-process as a product. The pre-process includes a step of exposing a wafer coated with a photosensitive agent using the above-described exposure apparatus, and a step of developing the wafer. The post-process includes an assembly process (dicing and bonding) and a packaging process (encapsulation). A liquid crystal display device is manufactured through a process of forming a transparent electrode. The step of forming the transparent electrode includes a step of applying a photosensitive agent to a glass substrate on which a transparent conductive film is deposited, a step of exposing the glass substrate on which the photosensitive agent is applied using the above-described exposure apparatus, and a glass substrate. The process of developing is included. According to the device manufacturing method of the present embodiment, it is possible to manufacture a higher quality device than before.

(Other embodiments)
As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

  In the said embodiment, although the shape of the circular mirror 13 was demonstrated as a concave surface, this invention is not limited to this, If it is circular, it is applicable also to a plane mirror or a convex mirror. Moreover, in the said embodiment, although it is set as the structure which supplies the temperature control air 18 from the ventilation part 19 installed in the surface center of the circular mirror 13, on the contrary, the temperature control air 18 is supplied from the outer peripheral part of the circular mirror 13, for example. However, it may be configured to collect at the center of the surface of the circular mirror 13. In this case as well, the same effects as in the above embodiment are achieved.

DESCRIPTION OF SYMBOLS 1 Exposure apparatus 3 Projection optical system 13 Circular mirror 14 Gas supply apparatus 18 Temperature control air 19 Blower part 20 Supply path 21 Air guide part 22 Rectifier plate 23 Rectification filter 26 Temperature sensor 27 Temperature sensor 30 Gas supply apparatus 31 Blower fan 32 Heat exchange 33 Chemical filter 34 Support member

Claims (9)

An exposure apparatus having a projection optical system including a circular mirror that reflects exposure light and a gas supply device that controls the temperature of the circular mirror,
The circular mirror has an arc-shaped irradiation area,
The gas supply device includes a blower unit located in a central region of the surface of the circular mirror while avoiding the irradiation region,
The air blowing part is formed of a cylindrical member whose surface facing the surface of the circular mirror is closed, and temperature-controlled air is drawn from the entire side surface of the cylindrical member along the surface of the circular mirror. An exposure apparatus characterized by supplying radially toward the outer peripheral area of the mirror. The gas supply device further includes an air supply device for supplying the temperature-controlled air,
The exposure apparatus according to claim 1, wherein the temperature-controlled air is supplied to the air blowing unit through a supply path that is installed while avoiding the irradiation region.   2. The exposure apparatus according to claim 1, wherein the blower is supported by a support member installed while avoiding the irradiation region, and includes a blower fan, a heat exchanger, and a filter.   The exposure apparatus according to any one of claims 1 to 3, wherein the blower unit includes a filter or a baffle plate for rectifying the flow of the temperature-controlled air.   5. The exposure apparatus according to claim 1, wherein the gas supply device includes a collection unit for collecting the temperature-controlled air installed so as to surround a side surface and a bottom surface of the circular mirror. . The blower unit has a temperature sensor that measures the temperature of the temperature-controlled air,
The exposure apparatus according to claim 1, wherein the gas supply device controls the temperature of the temperature-controlled air based on a value of the temperature sensor. The gas supply device has a temperature sensor that measures the temperature of the surface of the circular mirror,
The exposure apparatus according to claim 1, wherein the temperature of the temperature-controlled air is controlled based on the temperature of the circular mirror measured by the temperature sensor. The gas supply device has a temperature sensor that measures the temperature of the surface of the circular mirror,
The exposure apparatus according to claim 1, wherein a supply amount of the temperature-controlled air is controlled based on a temperature of the circular mirror measured by the temperature sensor. Exposing the substrate using the exposure apparatus according to claim 8;
Developing the exposed substrate;
A device manufacturing method comprising:

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