JP2005005395A - Gas feeding evacuation method and apparatus, mirror cylinder, exposure device, and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To construct an evacuation passage for gas easily with high workability. <P>SOLUTION: The evacuation passage 10 is formed in interior of a wall of a sealing room H, and an lower end of the passage 10 is connected continuously with the inside of the lower end of the sealing room H through an evacuation opening 11. The upper end of the passage 10 is prolonged to a height position of a partioning mirror cylinder 502 where a flange FL is formed. Gas in the sealing room H is evacuated together with degassing and dopant from an upper end of the passage 10 formed in the flange FL through the opening 11, and the passage 10 in the lower end of the sealing room H. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention provides a gas supply / exhaust method, a gas supply / exhaust device, and a gas supply / exhaust device for supplying gas into a sealed chamber while exhausting the gas and impurities in the sealed chamber, and holding an optical element The present invention relates to a lens barrel, an exposure apparatus that includes the lens barrel, and that transfers a pattern formed on a mask to a substrate and an exposure method.
[0001]
[Background]
Conventionally, when manufacturing semiconductor devices and liquid crystal display devices using lithography technology, exposure illumination light (exposure light) is irradiated onto the mask on which the pattern is formed, and an image of this mask pattern is projected. 2. Description of the Related Art An exposure apparatus that performs projection exposure on a photosensitive substrate such as a semiconductor wafer or a glass template coated with a photosensitive agent such as a photoresist via an optical system is used. In recent years, along with the demand for miniaturization of the pattern shape projected on the shot area on the substrate, the exposure light used tends to be shortened in wavelength. Instead of the conventional mercury lamp, KrF (krypton fluorine) is used. ) Exposure apparatuses using excimer laser (248 nm) and ArF (argon fluorine) excimer laser (193 nm) are being put into practical use. In addition, with the aim of further miniaturization of pattern shapes, F ₂ Development of an exposure apparatus using a (fluorine) laser (157 nm) is also in progress.
[0002]
In the case of vacuum ultraviolet light having a wavelength of exposure light of 180 nm or less, it is strong against light in such a wavelength range such as oxygen molecules, water molecules, carbon dioxide molecules, and organic substances in the optical path space where the exposure light passes. If a substance having absorption characteristics (hereinafter referred to as “light-absorbing substance”) exists, the exposure light is absorbed by the light-absorbing substance and cannot reach the substrate with sufficient intensity. Therefore, in an exposure apparatus using vacuum ultraviolet light, in order to transfer the pattern image of the mask onto the substrate with exposure light having a sufficient amount of light, an optical path space through which the exposure light passes is used as a sealed chamber for the absorption of light absorbing material from the outside. In addition to blocking the inflow, the work of reducing the light-absorbing substance existing in the optical path space is performed when performing the exposure process. Conventionally, as a method of reducing the light absorbing material in the optical path space, a material such as helium, argon, nitrogen, etc. (hereinafter referred to as “inert gas”) having a low absorption characteristic for exposure light is supplied into the optical path space. There is a method of filling the optical path space with an inert gas.
[0003]
By the way, in the exposure apparatus as described above, a plurality of optical elements (lenses) held by a lens barrel are arranged in an optical path space through which exposure light passes, and the optical path space is made a sealed chamber by the lens barrel. Yes. A gas supply pipe is connected to the upper part of the barrel, which is a sealed chamber, from the outside. The inert gas is supplied to the upper part of the barrel through this pipe, and the inert gas flows to the lower part of the barrel. Thereafter, impurities including inert gas and light-absorbing substances are exhausted from the lower part of the lens barrel through an exhaust pipe connected to the lower part of the lens barrel.
[0004]
[Problems to be solved by the invention]
The lens barrel is mounted on the body frame of the exposure apparatus via a flange formed at a predetermined height position on the outer peripheral surface, and the flange is fixed to the upper end surface of the body frame. The part above the flange of the lens barrel rises and projects from the upper end surface of the body frame, but the part below the flange of the lens barrel is inserted through the mounting hole formed in the upper end surface of the body frame and is inserted into the body frame. Be contained. For this reason, the part above the flange of the lens barrel is not surrounded by the body frame, and there is a relatively large space around it, whereas the part below the flange of the lens barrel has a mounting hole or body. Surrounded by a frame, there is no space around it. Also, the lowermost end of the lens barrel approaches the wafer stage, and peripheral devices related to the wafer stage are arranged around the wafer stage, and there is no particular space around the lowermost end of the lens barrel. .
[0005]
Therefore, when connecting the pipe from the outside to the lens barrel, it is difficult to connect the pipe at the lower part below the flange of the lens barrel, and it is particularly difficult to connect the pipe at the lowermost end of the lens barrel. It is very difficult.
[0006]
As described above, there is no space in the body frame of the exposure apparatus, the piping work becomes complicated, the work load becomes large, and the workability is lowered.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a gas supply / exhaust method and a gas supply / exhaust device capable of easily constructing a gas exhaust passage with good workability.
[0007]
It is another object of the present invention to provide a lens barrel in which a gas exhaust passage is constructed with good workability and the efficiency of assembling and adjusting work of the lens barrel itself can be improved.
[0008]
Furthermore, an exposure apparatus capable of performing an accurate exposure process by providing this lens barrel as a projection optical system, and an exposure method capable of performing an accurate exposure process by reducing light-absorbing substances in the optical path space are provided. The purpose is to do.
[0009]
[Means for Solving the Problems]
The gas supply / exhaust method according to claim 1 of the present invention, which achieves the above object, supplies gas from one end of the sealed chamber (H) (for example, the upper end of the sealed chamber), while the gas is in the sealed chamber. In the gas supply / exhaust method for exhausting the gas to the outside of the sealed chamber after flowing to the other end of the sealed chamber (for example, the lower end of the sealed chamber), the gas flowing to the other end of the sealed chamber is It is characterized by exhausting to the outside of the sealed chamber from a flange (FL) provided on the outer periphery of the sealed chamber or from between the flange (FL) and one end of the sealed chamber (H).
[0010]
In the air supply / exhaust device according to claim 5 of the present invention, the gas is supplied from one end of the sealed chamber (for example, the upper end of the sealed chamber), while the gas is supplied to the other end of the sealed chamber (for example, the sealed chamber). In the gas supply / exhaust device for exhausting the gas to the outside of the sealed chamber after flowing into the lower end of the sealed chamber, a flange provided on the outer periphery of the sealed chamber with the gas flowing to the other end of the sealed chamber (FL) or an exhaust mechanism (10, 11, 12, 20, 21, 211, 204) for exhausting the outside of the sealed chamber from between the flange and one end of the sealed chamber (H). It is characterized by that.
[0011]
That is, the gas that has flowed to the other end (lower end) of the sealed chamber is not exhausted from the other end to the outside of the sealed chamber, but once to the flange or flange and one end (upper end) of the sealed chamber. And then exhausted from the flange or from a position between the flange and one end of the sealed chamber to the outside of the sealed chamber.
[0012]
According to the air supply / exhaust method and apparatus of the present invention, the gas can be supplied without connecting the pipe to the lower part of the flange of the cylindrical body constituting the sealed chamber (without performing the piping work in a difficult place of the pipe). Exhaust can be performed. In addition, the gas supplied to the sealed chamber flows from one end (upper end) of the sealed chamber to the other end (lower end) (after flowing through the entire sealed chamber), and then escapes from the wall of the sealed chamber itself. Since the exhaust gas is exhausted together with the gas and the impurities present in the sealed chamber, the sealed chamber is gradually filled with a gas almost free of impurities by repeatedly supplying and exhausting the gas.
[0013]
In the gas supply / exhaust method and gas supply / exhaust device described above, an exhaust passage (10) is formed inside the wall of the sealed chamber, and the gas flowing to the other end of the sealed chamber via the exhaust passage is It is preferable to exhaust from the flange or between the flange and one end of the sealed chamber to the outside of the sealed chamber.
[0014]
As a result, the pipe that configures the sealed chamber with the pipe for temporarily returning the gas that has flowed to the other end (lower end) of the sealed chamber to a position between the flange and the flange and one end (upper end) of the sealed chamber. It is not necessary to connect to the body, gas can be supplied and exhausted without complicated piping work, and workability is improved.
[0015]
Further, an in-flange exhaust passage (20) that communicates with the exhaust passage is formed inside the flange, and the gas that has flowed to the other end of the sealed chamber is allowed to flow into the exhaust passage (10) and the in-flange exhaust passage ( It is preferable that the air is exhausted outside the sealed chamber via 20).
[0016]
Thereby, the length of the piping for exhausting gas or the like can be shortened as much as possible.
Further, an exhaust port (12) communicating with the exhaust passage is formed at a position between the flange and one end (upper end) of the sealed chamber, and the gas flowing to the other end of the sealed chamber is formed. It is preferable that the air is exhausted out of the sealed chamber through the exhaust passage (10) and the exhaust port (12).
[0017]
Thereby, piping for exhausting gas or the like becomes easier.
The lens barrel according to claim 9 of the present invention is a lens barrel (PK) that holds a plurality of optical elements (L1 to L13, etc.) and has a flange (FL) formed on the outer periphery. Gas supply device (203, 207, 215) for supplying gas from between one end of PK) and the flange (FL), and the gas flowing to the other end of the lens barrel (PK) Or an exhaust mechanism (10, 11, 12, 20, 21, 211, 204) for exhausting the outside of the lens barrel from between the flange and one end of the lens barrel.
[0018]
According to the lens barrel of the present invention, it is possible to supply and exhaust gas without connecting piping to the lower portion of the flange of the lens barrel (without performing piping work in places where piping is difficult). In addition, the gas supplied to the lens barrel flows from one end (upper end) of the lens barrel to the other end (lower end) (after flowing through the entire lens barrel), along with impurities present in the lens barrel. Since the gas is exhausted, the lens barrel is gradually filled with a gas having almost no impurities or the like by repeating the supply and exhaust of the gas.
[0019]
In the above-described lens barrel, an exhaust passage (10) extending from the other end portion of the lens barrel toward one end portion is formed inside the wall of the lens barrel, and the other end portion of the lens barrel is formed through the exhaust passage. It is preferable to exhaust the gas flowing to the outside of the lens barrel from the flange or between the flange and one end of the lens barrel.
[0020]
As a result, the gas that has flowed to the other end (lower end) of the lens barrel is temporarily connected to the flange or a pipe between the flange and one end (upper end) of the lens barrel without connecting to the lens barrel. In other words, gas can be supplied / exhausted without complicated piping work, and workability is improved.
[0021]
The exposure apparatus according to claim 13 of the present invention is an exposure apparatus comprising a projection optical system (150) for transferring a pattern formed on a mask (220) onto a predetermined surface, wherein the projection optical system includes a plurality of projection optical systems. The optical element (L1 thru | or L13 grade | etc.,) Is comprised, These optical elements are hold | maintained by the lens-barrel (PK) in any one of Claim 9 thru | or 12.
[0022]
According to the exposure apparatus of the present invention, by providing the above-described lens barrel of the present invention as a lens barrel that holds a plurality of optical elements of the projection optical system, a pipe is not connected to the lower portion of the flange of the lens barrel ( Gas can be supplied and exhausted without piping work in difficult locations). In addition, the gas supplied to the lens barrel flows from one end (upper end) of the lens barrel to the other end (lower end) (after flowing through the entire lens barrel), along with impurities present in the lens barrel. Since the gas is exhausted, the supply and exhaust of the gas is repeated, so that the lens barrel is gradually filled with a gas containing almost no impurities and the pattern can be transferred with high accuracy.
[0023]
An exposure method according to claim 18 of the present invention is an exposure method in which a pattern is exposed to exposure on a substrate (230) using exposure light (EL), and a space including the optical path of the exposure light is formed. While supplying gas into the sealed chamber (H), gas supply and exhaust for exhausting the gas out of the sealed chamber (H) after the gas flows to the other end of the sealed chamber (H), 5. The gas supply / exhaust method according to claim 1, wherein an exposure process is performed after the concentration of the gas in the sealed chamber (H) reaches a predetermined value.
[0024]
According to the exposure method of the present invention, the gas supply / exhaust of the sealed chamber forming the space including the optical path of the exposure light can be performed without connecting the piping to the lower portion of the flange of the cylindrical body constituting the sealed chamber (the piping (Without piping work in difficult places). In addition, the gas supplied to the sealed chamber flows from one end (upper end) of the sealed chamber to the other end (lower end) (after flowing through the entire sealed chamber) and then exhausted together with impurities existing in the sealed chamber. Therefore, by repeating the supply and exhaust of the gas, the sealed chamber is filled with a gas that hardly contains impurities, and the gas concentration in the sealed chamber reaches a predetermined value in a relatively short time. Furthermore, since the exposure process is performed after the gas concentration in the sealed chamber reaches a predetermined value, the exposure process can be performed with high accuracy.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of a gas supply / exhaust method, a gas supply / exhaust device, a lens barrel, an exposure apparatus, and an exposure method according to the present invention will be described with reference to FIGS.
[0026]
FIG. 1 is an overall configuration diagram showing an embodiment of a gas supply apparatus and an exposure apparatus of the present invention, and FIG. 2 is a longitudinal sectional view showing an embodiment of a projection optical system (lens barrel) equipped in the exposure apparatus of FIG. 3 is a longitudinal sectional view showing a modification of the projection optical system (lens barrel) in FIG. 2, and FIG. 4 (a) shows an exhaust passage formed in the wall portion of the split barrel 504 in FIG. 2 or FIG. 4B is a cross-sectional view taken along the line AA in FIG. 4A, and FIG. 5 is a vertical cross-sectional view showing a state in which the divided lens barrel 503 and the divided lens barrel 504 are connected. 6 is a partial longitudinal sectional view showing another embodiment of the connecting portion of the split lens barrel.
[0027]
First, the overall configuration and operation of the exposure apparatus of the present embodiment will be described with reference to FIG.
In the present embodiment, F is used as the exposure beam. ₂ The present invention will be described by exemplifying a step-and-scan type projection exposure apparatus using laser light.
[0028]
The exposure apparatus 100 includes a light source 110, an illumination optical system 120, a reticle operation unit 140, a projection optical system (PL) 150, a wafer operation unit 160, an alignment system 170, a local gas supply unit (purge unit) 180, an environment control system 200, and the like. It has a control part etc. which are not illustrated.
[0029]
In the following description, the direction orthogonal to the optical axis of the projection optical system 150 and perpendicular to the paper surface is the X direction, the direction orthogonal to the optical axis of the projection optical system 150 and parallel to the paper surface is the Y direction, and X A direction perpendicular to the Y direction and parallel to the optical axis of the projection optical system 150 is taken as a Z direction.
[0030]
The light source 110 generates a pulsed laser beam having a wavelength of 157 nm in the vacuum ultraviolet region. ₂ It is a laser. The light beam emitted from the light source 110 is incident on the illumination optical system 120.
[0031]
The illumination optical system 120 performs processing such as shaping the light beam emitted from the light source 110 and equalizing the illuminance, and irradiates the generated exposure light onto the reticle (R) 220 on which a pattern to be transferred is formed.
[0032]
The illumination optical system 120 includes a movable mirror, a beam matching unit (BMU) 121 that aligns the light beam emitted from the light source 110, and an optical attenuator 122 as a variable dimmer that adjusts the light beam attenuation rate. The beam shaping optical system 123 for shaping the light beam, the fly-eye lens 124 as an optical integrator for adjusting the light quantity distribution of the exposure light, and the light quantity distribution of the exposure light are determined by a circle, a plurality of eccentric regions, a ring band, etc. An aperture stop 125 that determines illumination conditions, a beam splitter 126 that branches a light beam to detect the amount of exposure light, mirrors 127 and 131, relay lenses 128 and 130, a reticle blind (field stop) 129 that defines an illumination area, and a condenser lens It has a system 132 and an illumination system chamber 133 that houses them.
[0033]
In such an illumination optical system 120, the light beam emitted from the light source 110 is adjusted in the beam matching unit 121 so that the optical axis coincides with the optical axis of the illumination optical system 120 and is incident on the optical attenuator 122. . The light attenuation rate of the optical attenuator 122 is adjusted stepwise or continuously based on a control signal from a control unit (not shown), thereby adjusting the amount of exposure light. Note that the adjustment of the amount of exposure light is performed together with the control of the output energy of the light beam in the light source 110.
[0034]
The light beam that has passed through the optical attenuator 122 has its cross-sectional shape shaped by the beam shaping optical system 123, the light quantity distribution is made uniform by the fly-eye lens 124, and then enters the beam splitter 126 through the aperture stop 125.
[0035]
The beam splitter 126 is a beam splitter 126 having a high transmittance and a low reflectance, and the light reflected thereby is incident on an integrator sensor (not shown) and the amount of light is measured. Based on the measured light quantity and the transmittance or reflectance of the beam splitter 126 stored in advance, the light quantity of the exposure light EL is detected by a control unit (not shown), and the light quantity is controlled based on this. Is done.
[0036]
The exposure light EL that has passed through the beam splitter 126 is reflected substantially in the horizontal direction by the mirror 127 and reaches the reticle blind 129 via the relay lens 128.
[0037]
Reticle blind 129 is disposed on a surface optically substantially conjugate with the pattern surface of reticle 220 to cover the outside of the illumination area (outside the exposure range) of the pattern surface of reticle 220, thereby shielding light that defines the illumination area of reticle 220. It is a board. The reticle blind 129 has a fixed blind and a movable blind, and extends in the X direction around the optical axis of the exposure light EL within the circular field of the projection optical system 150 within the illumination field of the reticle 220 irradiated with the exposure light EL. It is defined as a rectangular shape. The reticle blind 129 controls the width of the illumination area in the scanning direction (Y direction in the present embodiment) in which the reticle 220 is moved during scanning exposure to a predetermined width.
[0038]
The exposure light EL that has passed through the reticle blind 129 is incident on the reticle operation unit 140 via the relay lens 130, the mirror 131, and the condenser lens system 132, and illuminates a predetermined area on the pattern surface of the reticle 220.
[0039]
Each component from the beam matching unit 121 of the illumination optical system 120 to the condenser lens system 132 is an inert gas (transmitting gas such as helium, nitrogen, etc.) that absorbs little energy with respect to the exposure light EL that is F2 laser light. Or an illumination system chamber 133 filled with a mixed gas such as helium or nitrogen.
[0040]
The illumination system chamber 133 is connected to an inert gas recovery device 204 via a valve 209 and is connected to an inert gas supply device 203 via a valve 205. Accordingly, by opening the valve 205 and the valve 209, the air in the illumination system chamber 133 is exhausted, while the inert gas is supplied into the illumination system chamber 133, and the air in the illumination system chamber 133 is inactive. Replaced with gas.
[0041]
The reticle operation unit 140 is provided between the projection optical system 150 and the illumination optical system 120, holds a reticle (mask) 220, and applies the exposure light EL that is emitted from the illumination optical system 120 and incident on the projection optical system 150. The position and orientation are controlled so that a desired region of the pattern on the reticle 220 is appropriately irradiated.
[0042]
The reticle operation unit 140 includes a reticle stage 141, a laser interferometer system (not shown), and a reticle chamber 142.
The reticle stage 141 holds the reticle 220 so as to be movable in the Y direction with a predetermined stroke, and to be finely movable in the rotational direction and the translational direction within the XY plane. The reticle stage 141 is rotated by a laser interferometer system having at least six length measurement axes (not shown), and three rotation amounts (pitching amount, rolling amount, yawing) around the X, Y direction, X axis, Y axis, and Z axis. Amount) and a position in the Z direction (interval with the projection optical system 150) are measured. The reticle stage 141 adjusts the reticle 220 to a desired position and posture based on a control signal generated by a control unit (not shown) from these measurement results, and is synchronized with the movement of the wafer 230 during scanning exposure. Thus, the reticle 220 is moved at a predetermined speed in the scanning direction (Y direction) with respect to the illumination area of the exposure light EL.
[0043]
The reticle stage 141 is accommodated in a reticle chamber 142 filled with an inert gas that absorbs little energy with respect to the exposure light EL.
The reticle chamber 142 is connected to an inert gas recovery device 204 via a valve 210 and is connected to an inert gas supply device 203 via a valve 206. Accordingly, by opening the valve 206 and the valve 210, the air in the reticle chamber 142 is exhausted, while the inert gas is supplied into the reticle chamber 142, and the air in the reticle chamber 142 is replaced with the inert gas. Is done.
[0044]
The projection optical system 150 (PL) is a double-sided telecentric reduction system that forms a reduced image of the pattern of the reticle 220 in an exposure region conjugate with the illumination region of the exposure light EL (an irradiation region of the exposure light EL on the wafer 230). is there. That is, the pattern image of the reticle 220 is reduced by the projection optical system 150 at a predetermined reduction magnification α (α is, for example, 1/4, 1/5, etc.) and placed on the wafer stage of the wafer operation unit 160. Projected onto a wafer 230 having a surface coated with a photoresist.
[0045]
In this embodiment, the exposure light EL is F. ₂ Because it is a laser beam, an optical glass material with good transmittance is a meteorite (CaF ₂ ), Quartz glass doped with fluorine or hydrogen, and magnesium fluoride (MgF) ₂ ) Etc. Therefore, it is difficult to obtain the imaging characteristics such as desired chromatic aberration characteristics by configuring the projection optical system 150 only with the refractive optical member, and the projection optical system 150 is configured with the catadioptric system combining the refractive optical member and the reflecting mirror. To do.
[0046]
In the projection optical system 150, all optical members (all optical paths of the exposure light EL in the projection optical system 150) from the optical member (optical element) on the reticle 220 side to the optical member on the tip on the wafer 230 side are F ₂ It is accommodated in a lens barrel PK filled with an inert gas that absorbs little energy with respect to exposure light EL that is laser light.
[0047]
The lens barrel PK is mounted and fixed to a body frame (not shown) of the exposure apparatus via a flange FL (see FIG. 2 or 3) formed on the outer periphery thereof. The lens barrel PK is connected to an inert gas recovery device 204 via a valve 211 and is connected to an inert gas supply device 203 via a valve 207. Therefore, by opening each of the valve 207 and the valve 211, the air in the lens barrel PK is exhausted, while the inert gas is supplied into the lens barrel PK, and the air in the lens barrel PK is replaced with the inert gas. The
[0048]
Details of the inert gas supply / exhaust device S, the lens barrel PK equipped with the supply / exhaust device, and the projection optical system 150 will be described later with reference to FIGS.
The wafer operation unit 160 holds a wafer (sensitive substrate) 230 to be exposed, controls its position, and uses it as an irradiation target of the pattern image of the reticle 220 by the exposure light EL emitted from the projection optical system 150. Provide. At the time of scanning exposure, the position of the wafer 230 is sequentially moved in synchronization with the movement of the reticle 220 in the reticle operation unit 140.
[0049]
The wafer operation unit 160 includes a wafer stage 161 that holds the wafer 230, a laser interferometer system 162 that detects the position and orientation of the wafer stage, a stage drive system 163 that drives the wafer stage, and a wafer loader unit 164.
[0050]
The wafer stage 161 is supported on the base board and is supported on the stage main body by three Z-direction actuators, which is movable on the base board in an XY two-dimensional manner by a stage drive system. An adjustment stage for adjusting the inclination of the wafer, and a wafer holder that is supported on the adjustment stage and holds and holds the wafer 230 by a vacuum suction force from the suction holes formed on the surface, and is conveyed by the wafer loader unit 164 The mounted wafer 230 is held on the wafer holder in a desired posture and subjected to exposure.
[0051]
The laser interferometer system 162 has at least five measurement axes, irradiates a laser beam onto a reflection surface formed on the adjustment stage, position information in the X and Y directions of the wafer stage, and an X axis, Three rotation amounts around the Y axis and the Z axis, that is, a pitching amount, a rolling amount, and a yawing amount are measured.
[0052]
The stage drive system 163 moves the wafer stage supported on the base board freely in the X and Y two-dimensional directions.
The wafer loader unit 164 takes out the wafer 230 to be exposed from the wafer cassette loaded in the exposure apparatus 100 and places it on the wafer holder of the wafer stage 161. Further, the wafer 230 that has been subjected to the exposure processing is collected from the wafer stage and is stored in a predetermined position of a new wafer cassette.
[0053]
The alignment system 170 is provided on the alignment mark of the wafer 230 and the wafer stage of the wafer operation unit 160 in order to detect the position of the wafer 230 held by the wafer operation unit 160 and position the wafer 230 at a desired position. A reference mark or the like is detected, and the detection result is output to a control unit (not shown).
[0054]
The alignment system 170 irradiates a mark with, for example, broadband light generated from a halogen lamp, and outputs an image signal obtained by detecting the mark with an imaging device (CCD) to the control unit. In the control unit, this image signal is subjected to waveform processing to detect its position information.
[0055]
The local gas supply / exhaust unit (local fluid supply / discharge unit) 180 is an inert gas in a space (specific space) 181 between the optical member at the tip of the projection optical system 150 and the wafer 230 held by the wafer operation unit 160. Is caused to flow from a predetermined direction to eliminate the light-absorbing substance in the specific space 181. This also suppresses the outgas generated from the resist of the wafer 230 from adhering to the optical member at the tip.
[0056]
The environment control system 200 is a component for adjusting the installation environment of the exposure apparatus 100 main body and the path of the exposure light EL in the exposure apparatus 100 to a desired state.
The environment control system 200 includes a chamber 201, a filter 202, and an air supply / exhaust device S (inert gas supply device 203, inert gas recovery device 204).
[0057]
The chamber 201 is an environmental control chamber (environmental chamber) that accommodates the entire exposure apparatus 100. An air conditioner is provided in the chamber 201, and air whose temperature and humidity are adjusted is blown to the exposure apparatus 100, and the installation environment of the exposure apparatus 100 is maintained in a desired state.
[0058]
The filter 202 is an impurity removal filter that removes impurities such as chemical contamination by chemical adsorption and physical adsorption and a particle removal filter that removes dust in order to clean the inside of the chamber 201 in which the exposure apparatus 100 is installed. As described above, the exposure apparatus 100 is provided in the chamber 201, and the filter 202 is installed on the windward side of the air conditioner in the chamber 201. As a result, clean air is supplied to the exposure apparatus 100 in the chamber 201, and intrusion of impurities such as chemical contamination from the periphery of the exposure apparatus 100 to the exposure apparatus 100 can be prevented.
[0059]
The inert gas supply device 203 of the supply / exhaust device S includes an illumination system chamber 133 of the illumination optical system 120, a reticle chamber 142 of the reticle operation unit 140, a lens barrel 152 of the projection optical system 150, and a local gas supply / discharge unit 180. ₂ An inert gas with little energy absorption is supplied to the exposure light EL which is a laser beam.
[0060]
Specifically, the inert gas supply device 203 is a cylinder that is installed outside the chamber 201 in which the entire exposure apparatus 100 is accommodated and in which the inert gas is compressed or liquefied and stored in a high purity state. . Then, the valves 205 to 208 are each opened and closed under the control of a control unit (not shown), thereby supplying an inert gas to each component described above.
[0061]
In the exposure apparatus 100 of the present embodiment, vacuum ultraviolet light having a wavelength of 157 nm is used as the exposure light EL, and oxygen (O ₂ ), Water (water vapor: H ₂ O), carbon monoxide (CO), carbon dioxide (carbon dioxide: CO ₂ ), Organic substances, halides, etc., on the other hand, there is almost no energy absorption, and as a gas that permeates this, nitrogen gas (N ₂ ), Hydrogen (H ₂ ) And helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). In addition, when supplying a liquid between the projection optical system and the wafer, there are water and fluorine-based inert oil.
[0062]
Therefore, nitrogen gas or rare gas is suitable as the inert gas supplied by the inert gas supply device 203. In the present embodiment, the inert gas supply device 203 supplies nitrogen gas.
[0063]
Nitrogen gas can be used as a permeable gas up to a wavelength of about 150 nm, but acts as a light absorbing material for light of 150 nm or less. On the other hand, helium gas can be used as a permeable gas up to a wavelength of about 100 nm. Helium gas has a thermal conductivity of about 6 times that of nitrogen gas, and the amount of change in refractive index with respect to a change in atmospheric pressure is about 1/8 that of nitrogen gas.
[0064]
Therefore, when it is desired to further increase the transmittance and stabilize the characteristics of the optical system, or when the wavelength of the exposure light EL is 150 nm or less, helium is used as an inert gas (permeable gas), although the cost increases. It is desirable to use gas.
[0065]
The inert gas recovery device 204 of the air supply / exhaust device S has various portions to which the inert gas is supplied from the inert gas supply device 203, that is, the illumination system chamber 133 of the illumination optical system 120 and the reticle chamber of the reticle operation unit 140 described above. 142, a vacuum pump that exhausts the lens barrel 152 of the projection optical system 150 and the local gas supply / discharge unit 180.
[0066]
As described above, the inert gas recovery device 204 includes the illumination system chamber 133 of the illumination optical system 120, the reticle chamber 142 of the reticle operation unit 140, and the lens barrel 152 of the projection optical system 150 from the inert gas supply device 203. The air in each container is sucked and exhausted before the inert gas is supplied.
[0067]
Further, for the local gas supply / discharge unit 180, the inert gas recovery device 204 continuously applies the vacuum suction force through the valves 212 and 213 during the exposure process, and is supplied from the inert gas supply device 203. The gas in the specific space 181 containing the gas is exhausted. As a result, the inert gas flows in the specific space 181 at a certain speed, and the outgas generated from the wafer 230 can be exhausted from the specific space 181.
[0068]
A control unit (not shown) controls each component of the exposure apparatus 100 so that the exposure apparatus 100 can perform a desired exposure process as a whole.
Specifically, the wafer loader unit loads the wafer loaded into the exposure apparatus 100 onto the wafer stage, unloads the wafer after the exposure, and detects the position of the alignment mark based on the signal detected by the alignment system 170. Signal processing, control of the stage drive system based on the detected wafer stage and wafer position, movement of the reticle 220 and wafer 230 during scanning exposure, control of the position and orientation, and the like are performed.
[0069]
The control unit also projects the projection optical system 150 based on the amount of reflected light from the beam splitter 126 detected by the integrator sensor of the illumination optical system 120 and the transmittance or reflectance of the beam splitter 126 stored in advance. The amount of incident light and the amount of light on the wafer 230 are detected. Based on the detection result, the start and stop of light emission of the light source 110, the oscillation frequency, and the output determined by the pulse energy are controlled, the light attenuation rate in the optical attenuator 122 is adjusted, and finally the exposure to the wafer 230 is performed. Controls the amount of light EL.
[0070]
Next, the projection optical system 150 (PL) will be described in detail with reference to FIG.
The projection optical system 150 including the catadioptric optical system includes a refractive first imaging optical system G1 for forming a first intermediate image of the pattern of the reticle 220, a concave reflecting mirror CM, and two negative lenses L8 and L9. And a second imaging optical system G2 for forming a second intermediate image that is substantially the same size as the first intermediate image (second image of the reticle pattern that is a first intermediate image and a substantially equal magnification image). And a refractive third imaging optical system G3 for forming a final image of the reticle pattern (a reduced image of the reticle pattern) on the wafer (W) 230 based on the light from the second intermediate image. Yes.
[0071]
In the optical path between the first imaging optical system G1 and the second imaging optical system G2, in the vicinity of the position where the first intermediate image is formed, the light from the first imaging optical system G1 is sent to the second imaging optical system. A first optical path bending mirror 1 for deflecting toward the system G2 is arranged. Further, in the optical path between the second imaging optical system G2 and the third imaging optical system G3, the light from the second imaging optical system G2 is transmitted to the third optical in the vicinity of the formation position of the second intermediate image. A second optical path bending mirror 2 for deflecting toward the imaging system G3 is disposed. The first intermediate image and the second intermediate image are in the optical path between the first optical path folding mirror 1 and the second imaging optical system G2 and between the second imaging optical system G2 and the second optical path folding mirror 2. Each is formed in the optical path.
[0072]
The first imaging optical system G1 has a linearly extending optical axis AX1, and the third imaging optical system G3 has a linearly extending optical axis AX3. The optical axis AX1, the optical axis AX3, and the like. Are set to coincide with the reference optical axis AX which is a common single optical axis. The reference optical axis AX is positioned along the gravity direction (that is, the vertical direction). As a result, the reticle 220 and the wafer 230 are arranged in parallel to each other along a plane orthogonal to the direction of gravity, that is, a horizontal plane. In addition, all lenses constituting the first imaging optical system G1 and all lenses constituting the third imaging optical system G3 are also arranged along the horizontal plane on the reference optical axis AX.
[0073]
On the other hand, the second imaging optical system G2 also has a linearly extending optical axis AX2, and this optical axis AX2 is set to be orthogonal to the reference optical axis AX. Furthermore, the first optical path folding mirror 1 and the second optical path folding mirror 2 both have a planar reflecting surface, and are integrally configured as one optical member (one optical path folding mirror FM) having two reflecting surfaces. ing. The intersecting line of the two reflecting surfaces (strictly speaking, the intersecting line of the virtual extension surface) is AX1 of the first imaging optical system G1, AX2 of the second imaging optical system G2, and the third imaging optical system. It is set to intersect with AX3 of G3 at one point.
[0074]
The first imaging optical system G1 for forming a primary image (first intermediate image) of the pattern of the reticle 220 is composed of lenses L2 to L7. Further, on the most side of the projection optical system 150 on the reticle 220 side, a plane parallel plate L1 having a function of a lid for a purge space in the projection optical system 150 is provided. The plane parallel plate L1 and the lenses L2 to L7 are housed in divided lens barrels (sub-barrels) 301 to 307, respectively.
[0075]
The plane parallel plate 1L and the lenses L2 to L7 are connected to the divided lens barrels 301 to 307 via frames 311 to 317, respectively. The frames 311 to 317 are provided with openings for passing an inert gas (helium, nitrogen, etc.) flowing into the projection optical system 150 at a plurality of positions along the circumferential direction. . Note that an airtight structure is formed between the plane-parallel plate L1, the frame 311 and the divided barrel 301.
[0076]
The first imaging optical system G1 is provided with an actuator for moving the lenses L2, L3, L4, L5, L6, and L7 in the optical axis direction (Z direction) and tilting in the θx and θy directions. This actuator is provided at three positions that are equidistant from the optical axis and differ in the circumferential direction (θz method) at a pitch of 120 °. As the actuator, a linear motor, a piezo element, a cylinder mechanism driven by a pressurized fluid, or gas can be used. If the driving amounts of the three actuators are the same, each of the lenses can be moved in the optical axis direction. Further, by setting the driving amounts of the three actuators to be different from each other, each of the lenses can be inclined in the θx and θy directions. An actuator for moving the lens L3 in the XY plane is provided.
[0077]
The projection optical system 150 (PL) includes an optical path bending mirror FM in which the first optical path bending mirror 1 and the second optical path bending mirror 2 are integrally formed. The optical path bending mirror FM is formed, for example, by vapor-depositing a metal such as aluminum on two side surfaces of a triangular prism-shaped member whose upper surface and lower surface are right-angled isosceles triangles. A dielectric multilayer film may be deposited instead of the metal film. Further, instead of forming the first optical path bending mirror 1 and the second optical path bending mirror 2 on one member, the two plane mirrors may be held so as to be orthogonal to each other.
[0078]
The second imaging optical system G2 includes lenses L8 and L9 and a concave reflecting mirror CM. As the material of the concave reflecting mirror CM, SiC or a composite material of SiC and Si can be used. At this time, it is preferable to coat the entire concave reflecting mirror CM with SiC in order to prevent degassing. The reflecting surface of the concave reflecting mirror CM is formed by evaporating a metal such as aluminum. A dielectric multilayer film may be deposited instead of the metal film. A low thermal expansion material may be used as the concave reflecting mirror material.
[0079]
The optical path bending mirror FM and the lens L8 are housed in the split barrel 401, the lens L9 is housed in the split barrel 402, and the concave reflecting mirror CM is housed in the split barrel 403. A holding member 410 for holding the optical path bending mirror FM is attached to the split barrel 401. A mechanism is provided between the holding member 410 and the split lens barrel 401 for adjusting the orientation in the θx, θy, and θz directions and the position in the XYZ directions of the optical path folding mirror FM (first and second optical path folding mirrors). May be. The lenses L8 and L9 of the second imaging optical system G2 are supported by support members 411 and 412, respectively, and the concave reflecting mirror CM is supported by a support member 413.
[0080]
The third imaging optical system G3 includes lenses L10 to L13 and a variable aperture stop unit AS. Here, the lens L <b> 10 is housed in the split lens barrel 501, and the lens L <b> 11 is housed in the split lens barrel 502. The split lens barrel 502 is provided with a flange FL supported by a body frame (not shown) of the exposure apparatus at a predetermined height position on the outer periphery thereof.
[0081]
The variable aperture stop unit AS is housed in the divided lens barrel 503, and the lenses 12 and L13 are housed in the divided lens barrels 504 and 505, respectively. The lenses L10 to L13 are held by cells. The divided lens barrels 501, 502, 504, and 505 are connected to the cells by frames 521, 522, 524, and 525, respectively. The frames 521, 522, and 524 have openings for passing an inert gas (helium, nitrogen, etc.) flowing into the projection optical system 150 (PL) at a plurality of positions along the circumferential direction. Is provided. An airtight structure is formed between the lens L13 and the cell. The third imaging optical system G3 is provided with an actuator for moving the lenses L10 to L12 in the optical axis direction (Z direction) and tilting them in the θx and θy directions.
[0082]
The plurality of divided lens barrels constitute a lens barrel PK that holds each lens (optical element) of the projection optical system 150 (PL). By connecting each of these divided lens barrels, the projection optical system 150 (PL) The inside of the lens barrel PK, which is the optical path space of the exposure light EL, is a sealed chamber H.
[0083]
Next, an inert gas is supplied to the sealed chamber H in the barrel PK of the projection optical system 150 (PL), and the inert gas supplied from the sealed chamber H is removed from the wall of the sealed chamber H itself. The air supply / exhaust device S that exhausts gas and impurities together will be described in detail.
[0084]
A plurality of air supply / exhaust devices S are formed inside the wall of the sealed chamber H that exhausts the inert gas after the inert gas supplied from the upper end of the sealed chamber H flows to the lower end of the sealed chamber H. The exhaust passage 10 and a plurality of in-flange exhaust passages 20 formed in the flange FL and communicating with the exhaust passage 10 are provided.
[0085]
The upper end of the sealed chamber H is connected to an inert gas supply device 203 via a pipe 215 and a pipe valve 207.
The exhaust passage 10 extends in the direction of the optical axis AX3 inside the wall of the barrel PK (divided barrels 502, 503, 504, and 505) that holds the lenses L11 to L13 of the third imaging optical system G3 and the variable aperture unit AS. Is formed.
[0086]
The lower end of the exhaust passage 10 communicates with the inside of the lower end portion of the sealed chamber H via the exhaust opening 11 formed on the inner peripheral surface of the divided lens barrel 505, and the inert gas flowing to the lower end portion of the sealed chamber H is The gas flows into the exhaust passage 10 together with degassed and impurities from the exhaust opening 11. The upper end of the exhaust passage 10 extends to the height position of the split lens barrel 502 in which the flange FL is formed, and the upper end of the exhaust passage 10 is the inner end of the in-flange exhaust passage 20 (the end of the flange FL on the split lens barrel 502 side). The inert gas or the like that has risen in the exhaust passage 10 flows into the flange internal passage 20 from the upper end of the exhaust passage 10. The outer end of the flange inner passage 20 is connected to the pipe 21 on the outer peripheral surface of the flange FL, and is connected to the inert gas recovery device 204 through the pipe 21 and the pipe valve 211 from the outer end. The inert gas or the like flowing into the flange exhaust passage 20 is recovered by the inert gas recovery device 204 via the pipe 21 and the pipe valve 211.
[0087]
As shown in FIG. 4A, six exhaust passages 10 are formed at equal intervals in the circumferential direction of the divided lens barrel 504 (502, 503, 505). The exhaust passage 10 is a through hole provided by, for example, drilling. By using the exhaust passage 10 as a through hole formed by drilling or the like, the inner diameter of the hole can be arbitrarily set in order to obtain an exhaust amount corresponding to the inflow amount of the inert gas, for example.
[0088]
The flange FL is provided with a plurality of mounting holes (not shown) penetrating in the axial direction for fastening members (bolts) for fixing to the body frame of the exposure apparatus. In order to avoid the hole, it is formed to extend radially at six locations at equal intervals in the circumferential direction.
[0089]
The upper end surface of the divided barrel 504 is appropriately polished, and as shown in FIG. 4A, the upper end surface of the divided barrel 504 has an exhaust passage 10 with respect to the inner peripheral surface of the divided barrel 504. A seal member 30 is disposed at the outer position. The seal member 30 is configured by, for example, an O-ring. According to the arrangement of the seal member 30, the inert gas in the lens barrel PK does not leak to the outside. Instead of the O-ring, a sheet made of a fluorine-based resin or polytetrafluoroethylene (Teflon (registered trademark)) provided outside the exhaust passage 10 by coating or pasting may be used as the seal member 30. Is possible.
[0090]
A modified example in the case of providing a sealing member such as an O-ring between the divided lens barrels will be described.
In the present embodiment, as shown in FIG. 4A, the case where the seal member 30 such as an O-ring is disposed outside the exhaust passage 10 with respect to the inner peripheral surface of the divided lens barrel 504 is shown. A configuration in which a seal member 30 such as an O-ring is provided at an inner position of the exhaust passage 10 with respect to the inner peripheral surface of the lens barrel 504 may be employed. With this arrangement of the seal member 30, the gas in the exhaust passage 10 may leak out of the apparatus, but the inert gas in the lens barrel PK will not leak out. Further, a sealing member 30 such as an O-ring may be disposed around each exhaust passage 10. In this case, the O-ring having a shape that is slightly larger than the exhaust passage 10 may be used.
[0091]
Further, it is possible to seal by eliminating a leaking substance by forming a groove in the joint portion of the divided lens barrel and exhausting the groove under reduced pressure. This decompression groove method is more preferable because it can be used in combination with a seal member 30 such as an O-ring.
[0092]
The split lens barrel 504 has been described above, but the other split lens barrels 501, 502, 503, and 505 of the third imaging optical system G3 have the same configuration. In addition, the seal member 30 is also disposed in the divided barrels 301, 302, 303, 304, 305, 306, 307 of the first imaging optical system G1, the divided barrel 401 of the second imaging optical system G2, and the like. .
[0093]
As described above, the lens barrel PK of the projection optical system 150 (PL) is configured by connecting a plurality of divided lens barrels. FIG. 5 shows a state in which the split lens barrel 503 that supports the variable aperture unit AS and the split lens barrel 504 that supports the lens 12 are connected. As shown in FIG. 5, the exhaust passage 10 of the split barrel 503 and the exhaust passage 10 of the split barrel 504 are also connected to each other.
[0094]
A seal member 30 is provided between the divided lens barrel 503 and the divided lens barrel 504 and outside the exhaust passage 10. Therefore, impurity gas (absorbing substance such as oxygen) does not enter from the outside of the lens barrel PK through the connection surface between the segmented lens barrel 503 and the segmented lens barrel 504. Even if it has entered, it will flow into the exhaust passage 10 before reaching the interior of the lens barrel PK, and will be carried along with the inert gas etc. flowing through the exhaust passage 10 to the exhaust passage 20 in the flange and exhausted. Absent.
[0095]
When connecting the divided barrel 503 and the divided barrel 504, the divided barrel 503 is placed on the divided barrel 504 so that the exhaust passages 10 of the respective divided barrels 503 and 504 are connected to each other. Positioning is performed by sliding the divided barrel 503 on the divided barrel 504 so that the central axes (optical axes) of the divided barrels 503 and 504 coincide with each other. Like the other divided lens barrels, the divided lens barrel 503 is heavy, so that the divided lens barrel 503 is slightly lifted so as to be slidable on the divided lens barrel 504, and the sealing effect of the seal member 30 is increased. Move while maintaining and align. After the alignment is completed, the divided lens barrel 503 and the divided lens barrel 504 are fixed by a fixing member (not shown) such as a bolt. As shown in FIG. 5, in the present embodiment, each of the divided lens barrels has a straight barrel shape. However, as shown in FIG. 6, a flange portion 31 is provided at the end of the divided lens barrel. The divided lens barrels may be connected to each other by a fixing member such as a bolt. In this case, since the connection surface becomes large, it becomes easy to provide the seal member 30, and when fixing the divided lens barrel, it becomes easy to provide fixing members such as bolts and clamps.
[0096]
The case where the divided lens barrel 503 and the divided lens barrel 504 are connected has been described above. However, the other divided lens barrels 501, 502, 503, 505 and the first image forming optical system G1 of the third image forming optical system G3 are described. The connection between the divided lens barrels 301, 302, 303, 304, 305, 306, 307 and the divided lens barrel 401 of the second imaging optical system G2 is similarly performed.
[0097]
Next, a method for supplying and exhausting an inert gas into the sealed chamber H which is an optical path space of the exposure light EL formed in the lens barrel PK by the supply / exhaust device S configured as described above, and the sealed chamber H A method for exposing the wafer 230 with a pattern image formed on the reticle 220 using the exposure apparatus 100 supplied with an inert gas will be described.
[0098]
An inert gas is supplied from the inert gas supply device 203 to the upper end of the sealed chamber H through the pipe 215 and the pipe valve 207. The supplied inert gas reaches the whole sealed chamber H through an opening formed in a frame that supports each lens. After the inert gas flows to the lower end portion of the sealed chamber H, the inert gas degass from the wall portion itself of the sealed chamber H and from the exhaust opening 11 at the lower end portion of the sealed chamber H together with impurities such as oxygen that absorbs exposure light. It flows into the exhaust passage 10. Next, the inert gas, degassing, impurities, and the like rise in the exhaust passage 10 and reach the upper end portion of the exhaust passage 10 that is substantially the same as the height position at which the flange FL is formed. It flows into the exhaust passage 20. Thereafter, the inert gas, degassed, impurities and the like are sent from the in-flange exhaust passage 20 to the inert gas recovery device 204 through the piping valve 211 and the piping 21. The inert gas recovery device 204 recovers and regenerates the inert gas.
[0099]
The method for supplying the inert gas into the lens barrel PK of the projection optical system 150 (PL) has been described above. However, the valves 205 and 209 are also opened in the illumination system chamber 133 of the illumination optical system 120 and the interior of the illumination system chamber 133 is set. The air is exhausted while an inert gas is supplied into the illumination system chamber 133 to fill the illumination system chamber 133 with the inert gas. Further, the valves 206 and 210 are also opened for the reticle chamber 142 to exhaust the air in the reticle chamber 142 while supplying the inert gas into the reticle chamber 142 to fill the reticle chamber 142 with the inert gas. Further, for the space (specific space) 181 between the front end of the projection optical system 150 and the wafer 230 held by the wafer operation unit 160, the valves 208, 212, and 213 are opened and inactivated by the local gas supply / exhaust unit 180. The light-absorbing substance in the specific space 181 is excluded by flowing the gas from a predetermined direction.
[0100]
The reticle chamber 142 may also be configured not to be sealed like the specific space 181 and may be purged locally so that an inert gas is allowed to flow from a predetermined direction so as to eliminate light-absorbing substances in the reticle chamber 142. Good.
[0101]
In this way, an atmosphere in which the exposure light EL is hardly absorbed is formed over the entire optical path from the light source 110 to the wafer 230. When the concentration of the inert gas in the sealed chamber H forming the optical path space reaches a predetermined value, the exposure light EL is illuminated from the illumination optical system 120 onto the reticle 220 supported by the reticle stage 141, and the reticle 220 is formed on the reticle 220. The pattern image is transferred to the wafer 230 via the projection optical system 150. Here, the predetermined value of the concentration of the inert gas is an inert gas concentration value that allows a pattern to be formed with a desired accuracy without attenuating the amount of exposure light EL that is vacuum ultraviolet light. Whether or not the concentration of the inert gas in the optical path space has reached a predetermined value is determined based on a measured value of an inert gas concentration meter or a light-absorbing substance concentration meter provided in a part of the optical path space.
[0102]
According to the present embodiment, an inert gas is supplied from the upper end of the sealed chamber H, and after the inert gas flows to the lower end of the sealed chamber H, the height of the flange FL is increased from the exhaust opening 11 through the exhaust passage 10. Since the exhaust gas is exhausted through the in-flange exhaust passage 20 provided in the flange FL, the exhaust gas is exhausted to a portion below the flange FL of the lens barrel PK (a place where piping work is difficult). It is not necessary to connect the pipes for use. Further, since the exhaust passage 20 is formed in the flange FL, the flange FL can be effectively used, and the length of the exhaust pipe can be shortened as much as possible. Further, the flange FL itself supports the weight of the lens barrel PK, and is sufficiently strong. Even if the in-flange exhaust passage 20 is formed, no problem occurs. Furthermore, after the inert gas has spread over the entire sealed chamber H, it can be exhausted with degassing, impurities, etc., and the entire sealed chamber H can be filled with the inert gas in a relatively short time.
[0103]
In addition, since the exposure process is performed after the concentration of the inert gas in the sealed chamber H reaches a predetermined value, the exposure process can be accurately performed with the exposure light EL having a sufficient amount of light.
[0104]
FIG. 3 is a longitudinal sectional view showing a modification of the projection optical system (lens barrel) of FIG. In FIG. 3, the same components as those shown in FIG.
In this modification, the exhaust passage 10a is placed in the wall of the barrel PK (divided barrels 502, 503, 504, and 505) along the optical axis so that the upper end of the exhaust passage 10a exceeds the height position of the flange FL. The exhaust passage 10a is communicated with the exhaust port 12 formed on the outer peripheral surface at a position between the upper end portion of the lens barrel PK and the flange FL (a position higher than the flange FL of the divided lens barrel 502). . The exhaust port 12 is connected to an inert gas recovery device 204 via a piping valve 211 and a piping 21. Six exhaust passages 10a are formed at equal intervals along the circumferential direction of the lens barrel PK, and six exhaust ports 12 are formed at equal intervals along the circumferential direction of the lens barrel PK according to the exhaust passage 10a.
[0105]
Also in this modification, the inert gas is supplied from the inert gas supply device 203 to the upper end portion of the sealed chamber H through the pipe 215 and the pipe valve 207, and the supplied inert gas is supplied to the frame that supports each lens. It reaches the entire sealed chamber H through the formed opening. After the inert gas flows to the lower end portion of the sealed chamber H, the inert gas degass from the wall portion itself of the sealed chamber H and from the exhaust opening 11 at the lower end portion of the sealed chamber H together with impurities such as oxygen that absorbs exposure light. The gas flows into the exhaust passage 10a, rises in the exhaust passage 10a, reaches the upper end portion of the exhaust passage 10a, and passes through the pipe valve 211 and the pipe 21 from the exhaust port 12 at a position higher than the flange FL from the upper end portion. To the inert gas recovery device 204. The inert gas recovery device 204 recovers and regenerates the inert gas.
[0106]
According to this modification, it is not necessary to connect the exhaust pipe to the portion below the flange FL of the lens barrel PK (a place where piping work is difficult). Further, instead of forming the in-flange exhaust passage 20 inside the flange FL, the exhaust passage 10a is extended to a position higher than the height position where the flange FL is formed, and is formed on the outer peripheral surface of the lens barrel PK (divided lens barrel 502). Since the exhaust port 12 communicating with the exhaust passage 10a is provided, the processing is simpler than the case where the in-flange exhaust passage 20 is formed inside the flange FL. Further, in the case shown in FIG. 2, the flange exhaust passage 20 is formed so as to avoid the position of the mounting hole of the flange FL and is restrained by the position of the mounting hole of the flange FL. In the modified example, the position of the exhaust port 12 does not have such a restriction, and there is a degree of freedom in design.
[0107]
In the present embodiment of FIG. 2 and the modification of FIG. 3, the exhaust passages 10 and 10a are both formed inside the wall of the lens barrel PK, but for example, on the outer peripheral surface or inner peripheral surface of the lens barrel PK. A pipe may be fixed along the pipe, and the pipe may be used as the exhaust passages 10 and 10a. Further, the pipe may be formed in a spiral shape in addition to a linear shape extending in the optical axis direction.
[0108]
The case where the inert gas recovered from the inert gas, degassed, impurities, etc. exhausted from the sealed chamber H is recovered and recovered by the inert gas recovery device 204 has been described. However, the inert gas is recovered and recovered. Instead, it may be exhausted to the outside as it is degassed.
[0109]
In the present embodiment, the projection optical system configured by the catadioptric system has been described, but the configuration of the projection optical system is not limited to this configuration. For example, a refractive projection optical system constituted by a refractive optical member (lens) or a reflective projection optical system constituted by a reflective optical member (reflection mirror) may be used.
[0110]
Although the step-and-scan type projection exposure apparatus is exemplified as the exposure apparatus of the present embodiment, the present invention is not limited to this. For example, the pattern of the reticle 220 is illuminated while the reticle 220 and the wafer 230 are stationary. The present invention can also be applied to a step-and-repeat type exposure apparatus that sequentially moves the wafer 230 in steps.
[0111]
The use of the exposure apparatus is not limited to the exposure apparatus for manufacturing a semiconductor, but for example, an exposure apparatus for liquid crystal that exposes a liquid crystal display element pattern on a square glass plate and an exposure apparatus for manufacturing a thin film magnetic head. Widely applicable.
[0112]
In the present embodiment, F is used as the exposure beam. ₂ Although the case where laser light is used is shown, the present invention is not limited to this. For example, a KrF excimer laser (248 nm), an ArF excimer laser (193 nm), or the like can be used.
[0113]
【The invention's effect】
According to the gas supply / exhaust method of claim 1 and the supply / exhaust device of claim 5, the gas flowing to the other end of the sealed chamber is exhausted from the other end to the outside of the sealed chamber. Rather than return to the flange or the position between the flange and one end of the sealed chamber (the part above the flange), and from the flange or from the position between the flange and one end of the sealed chamber, Since exhaust is exhausted outside, piping is not connected between the flange of the cylinder that forms the sealed chamber and the other end of the cylinder (the part below the flange) (where piping is difficult) Gas supply / exhaust can be performed without piping work). In addition, after the gas supplied to the sealed chamber flows from one end of the sealed chamber to the other end (after flowing through the entire sealed chamber), degassing from the wall of the sealed chamber itself or impurities present in the sealed chamber Therefore, by repeating the gas supply and exhaust, the sealed chamber is gradually filled with a gas that is almost free of impurities and the like.
[0114]
According to the gas supply / exhaust method according to claim 2 or the supply / exhaust device according to claim 6, an exhaust passage is formed inside the wall of the sealed chamber, and the other end of the sealed chamber is formed through this exhaust passage. Since the flowed gas is exhausted from the flange or between the flange and one end of the sealed chamber to the outside of the sealed chamber, the gas flowing to the other end of the sealed chamber is once sealed with the flange or the flange. It is not necessary to connect the pipe for returning to the position between one end of the chamber to the cylinder that forms the sealed chamber, and gas can be supplied and exhausted without complicated piping work, improving workability. To do.
[0115]
According to the gas supply / exhaust method according to claim 3 and the supply / exhaust device according to claim 7, an in-flange exhaust passage communicating with the exhaust passage is formed inside the flange and flows to the other end of the sealed chamber. Since the exhausted gas is exhausted to the outside of the sealed chamber through the exhaust passage and the exhaust passage in the flange, the length of the pipe for exhausting the gas or the like can be shortened as much as possible. .
[0116]
According to the gas supply / exhaust method of claim 4 and the supply / exhaust device of claim 8, the exhaust passage communicates with a position (a portion above the flange) between the flange and one end of the sealed chamber. An exhaust port is formed so that the gas flowing to the other end of the sealed chamber is exhausted to the outside of the sealed chamber through the exhaust passage and the exhaust port. It becomes easier.
[0117]
According to the lens barrel of the ninth aspect, the gas supply device that supplies gas from between one end of the lens barrel and the flange, and the gas that has flowed to the other end of the lens barrel from the flange or the flange and the mirror. Since it includes an exhaust mechanism that exhausts air from the space between one end of the tube (portion above the flange) to the outside of the tube, the space between the flange of the tube and the other end of the tube (below the flange) It is possible to supply and exhaust gas without connecting pipes to (part) (without performing piping work in places where piping is difficult). In addition, the gas supplied to the lens barrel flows from one end of the lens barrel to the other end (after flowing through the entire lens barrel) and is then exhausted together with impurities present in the lens barrel. By repeating the evacuation, the lens barrel is gradually filled with a gas that hardly contains impurities.
[0118]
According to the lens barrel of the tenth aspect, an exhaust passage extending from the other end portion of the lens barrel toward the one end portion is formed inside the wall of the lens barrel, and the other end portion of the lens barrel is formed through the exhaust passage. Since the gas that has flowed to the outside of the lens barrel is exhausted from the flange or between the flange and one end of the lens barrel, the gas that has flowed to the other end of the lens barrel is temporarily It is not necessary to connect the piping for returning to the position between the one end of the lens barrel to the lens barrel. Gas can be supplied and exhausted without performing complicated piping work, and workability is improved.
[0119]
According to the exposure apparatus of the thirteenth aspect, the projection optical system is composed of a plurality of optical elements, and the plurality of optical elements are held by the lens barrel according to any one of the ninth to twelfth aspects. Without connecting the pipe between the flange of the lens barrel and the other end of the lens barrel (the part below the flange of the lens barrel) (without performing piping work in difficult locations), Supply and exhaust can be performed. In addition, the gas supplied to the lens barrel flows from one end of the lens barrel to the other end (after flowing through the entire lens barrel) and is then exhausted together with impurities present in the lens barrel. By repeating the evacuation, the lens barrel is gradually filled with a gas that hardly contains impurities and the pattern can be transferred with high accuracy.
[0120]
According to the exposure method of claim 18, the gas is supplied into the sealed chamber forming the space including the optical path of the exposure light, and after the gas flows to the other end of the sealed chamber, the gas is supplied to the outside of the sealed chamber. The gas supply / exhaust method is performed by the gas supply / exhaust method according to any one of claims 1 to 4, and the exposure process is performed after the concentration of the gas in the sealed chamber reaches a predetermined value. The gas supply / exhaust of the sealed chamber forming the space including the optical path of the exposure light is performed by connecting a pipe between the flange of the cylinder constituting the sealed chamber and the other end of the cylinder (a portion below the flange). It can be performed without connection (without performing piping work in difficult piping locations). In addition, after the gas supplied to the sealed chamber flows from one end of the sealed chamber to the other end (lower end) (after flowing through the entire sealed chamber), it is exhausted together with impurities existing in the sealed chamber. By repeating the supply and exhaust of the gas, the sealed chamber is filled with a gas that hardly contains impurities, and the gas concentration in the sealed chamber reaches a predetermined value in a relatively short time. Furthermore, since the exposure process is performed after the gas concentration in the sealed chamber reaches a predetermined value, the exposure process can be performed with high accuracy.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing an embodiment of a gas supply apparatus and an exposure apparatus of the present invention.
2 is a longitudinal sectional view showing an embodiment of a projection optical system (lens barrel) equipped in the exposure apparatus of FIG.
3 is a longitudinal sectional view showing a modification of the projection optical system (lens barrel) in FIG. 2;
4A is a cross-sectional view showing an exhaust passage formed in the wall portion of the split lens barrel 504 of FIG. 2 or FIG. FIG. 4B is a cross-sectional view taken along line AA in FIG.
FIG. 5 is a longitudinal sectional view showing a state in which a divided lens barrel 503 and a divided lens barrel 504 are joined.
FIG. 6 is a partial longitudinal sectional view showing another embodiment of the connecting portion of the split lens barrel.
[Explanation of symbols]
10 Exhaust passage
11 Exhaust opening
12 Exhaust port
20 Exhaust passage in flange
21 Piping
150 Projection optical system
203 Inert gas supply device
204 Inert gas recovery device
207, 211 Piping valve
215 piping
PK tube
H Sealed room
S air supply and exhaust system

Claims (21)

In the gas supply / exhaust method for supplying gas from one end of the sealed chamber, and after exhausting the gas to the other end of the sealed chamber, the gas is exhausted out of the sealed chamber.
The gas flowing to the other end of the sealed chamber is exhausted from a flange provided on the outer periphery of the sealed chamber or between the flange and one end of the sealed chamber to the outside of the sealed chamber. How to supply and exhaust gas. The gas supply / exhaust method according to claim 1,
The gas that has flowed to the other end of the hermetic chamber passes through an exhaust passage formed inside the wall of the hermetic chamber and from the flange or between the flange and one end of the hermetic chamber. A gas supply / exhaust method, characterized by being exhausted outside. The gas supply / exhaust method according to claim 2,
A gas supply / exhaust method according to claim 1, wherein the gas is exhausted out of the sealed chamber through an in-flange exhaust passage formed in the flange, which communicates with the exhaust passage. The gas supply / exhaust method according to claim 2,
The gas supply is characterized in that the gas is exhausted outside the sealed chamber through an exhaust port formed at a predetermined position between the flange and one end of the sealed chamber, which communicates with the exhaust passage. Exhaust method. In the gas supply / exhaust device for exhausting the gas out of the sealed chamber after supplying the gas from one end of the sealed chamber while the gas flows to the other end of the sealed chamber,
An exhaust mechanism for exhausting the gas flowing to the other end of the sealed chamber from a flange provided on the outer periphery of the sealed chamber or from between the flange and one end of the sealed chamber to the outside of the sealed chamber; A gas supply / exhaust device. The gas supply / exhaust device according to claim 5,
The gas supply / exhaust device, wherein the exhaust mechanism includes an exhaust passage formed in a wall of the sealed chamber that extends from the other end of the sealed chamber toward one end. The gas supply / exhaust device according to claim 6,
The gas supply / exhaust device, wherein the exhaust mechanism includes an in-flange exhaust passage formed in the flange and communicating with the exhaust passage. The gas supply / exhaust device according to claim 6,
The gas supply / exhaust device, wherein the exhaust mechanism includes an exhaust port formed at a predetermined position between the flange and one end of the sealed chamber and communicating with the exhaust passage. In a lens barrel that holds a plurality of optical elements and has a flange formed on the outer periphery,
A gas supply device for supplying gas from between one end of the lens barrel and the flange;
A lens barrel comprising: an exhaust mechanism that exhausts the gas flowing to the other end portion of the lens barrel from the flange or between the flange and one end portion of the lens barrel to the outside of the lens barrel. . The lens barrel according to claim 9, wherein
2. The lens barrel according to claim 1, wherein the exhaust mechanism includes an exhaust passage formed in a wall of the lens barrel extending from the other end of the lens barrel toward one end. The lens barrel according to claim 10,
The lens barrel characterized in that the exhaust mechanism includes an in-flange exhaust passage formed in the flange and communicating with the exhaust passage. The lens barrel according to claim 10,
The lens barrel characterized in that the exhaust mechanism includes an exhaust port formed at a predetermined position between the flange and one end of the lens barrel and communicating with the exhaust passage. In an exposure apparatus including a projection optical system that transfers a pattern formed on a mask onto a predetermined surface,
The exposure apparatus according to claim 9, wherein the projection optical system includes a plurality of optical elements, and the plurality of optical elements are held by the lens barrel according to any one of claims 9 to 12. The exposure apparatus according to claim 13, wherein
The exposure apparatus characterized in that the exhaust passage extends in the optical axis direction of the projection optical system. The exposure apparatus according to claim 12 or 13,
An exposure apparatus wherein light passing through the lens barrel is light having a wavelength of 200 nm or less. The exposure apparatus according to any one of claims 13 to 15,
An exposure apparatus, wherein the gas is a gas that absorbs little light passing through the lens barrel or has a low absorption rate of the light. The exposure apparatus according to any one of claims 13 to 16,
An exposure apparatus wherein the gas is nitrogen gas or a rare gas. In an exposure method of transferring and exposing a pattern to an exposed substrate using exposure light,
A gas supply / exhaust for supplying gas into a sealed chamber forming a space including the optical path of the exposure light, and exhausting the gas out of the sealed chamber after the gas has flowed to the other end of the sealed chamber. An exposure method comprising: performing the exposure process after the gas concentration in the sealed chamber reaches a predetermined value by the gas supply / exhaust method according to any one of claims 1 to 4. The exposure method according to claim 18, wherein
The exposure method, wherein the exposure light is light having a wavelength of 180 nm or less. The exposure method according to claim 18 or 19,
An exposure method, wherein the gas is a gas that does not absorb the exposure light or has a low absorptivity of the exposure light. The exposure method according to any one of claims 18 to 20,
An exposure method, wherein the gas is nitrogen gas or a rare gas.

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