JP2005064210A - Method for exposure, and method of manufacturing electronic device and exposure device utilizing the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for exposure by which the intensity unevenness (illumination unevenness) of exposing light is reduced as much as possible by roughly uniformizing the distribution of the arriving amount of a gas discharged from a resist at the surface of an optical element at the lowermost position of a projection optical system. <P>SOLUTION: A local gas supplying/discharging section 180 is provided with two openings 183 and 184. The opening 183 is connected to an inert gas supplying device 203 or an inert gas recovering device 204 through an inert gas supplying/discharging pipe 196, a stop valve 208, and a switching valve 215. The opening 184 is connected to the inert gas supplying device 203 or inert gas recovering device 204 through an inert gas supplying/discharging pipe 197, a stop valve 212, and a switching valve 216. The distribution of the arriving amount of the gas discharged from the resist at the surface of the optical element at the lowermost position of the projection optical system is roughly uniformized, by making an inert gas flow toward the opening 184 from the opening 183 and toward the opening 183 from the opening 184 after a prescribed time interval. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an exposure method used in a fine pattern forming process required in a manufacturing process of an electronic device such as a semiconductor integrated circuit, a liquid crystal display, an imaging device, and a magnetic head, and an electronic device manufacturing method using the exposure method And an exposure apparatus.

  When manufacturing a semiconductor device or a liquid crystal display device in a photolithography process, the pattern image of the reticle is reduced to each projection (shot) region on the wafer coated with a photosensitive material (photoresist) via a projection optical system. Thus, a reduction projection exposure apparatus that projects in this manner is used. The circuit in the semiconductor element is formed by transferring the circuit pattern on the wafer by exposing it with the projection exposure apparatus, and performing post-processing on the wafer.

In recent years, integrated circuits have been integrated at high density, that is, circuit patterns have been miniaturized. For this reason, the projection light in the projection exposure apparatus also tends to be shortened in wavelength. In other words, KrF excimer laser (248 nm) is used in place of the emission lines of mercury lamps that have been the mainstream until now, and the practical use of projection exposure apparatus using short wavelength ArF excimer laser (193 nm) is also in the final stage. Entering. In addition, research on an exposure apparatus using an F ₂ laser (157 nm) is also progressing for further high-density integration.

In general, ultraviolet light having a wavelength of about 190 nm or less is also called vacuum ultraviolet light and does not transmit through air. This is because light is absorbed by substances (hereinafter referred to as light-absorbing substances) such as oxygen molecules (O ₂ ), water molecules (H ₂ O), and carbon dioxide molecules (CO ₂ ) contained in the air. For this reason, in an exposure apparatus using vacuum ultraviolet light, it is necessary to reduce or eliminate light-absorbing substances on the exposure optical path in order to allow the exposure light to reach the wafer surface with sufficient illuminance. In general, in order to perform a semiconductor manufacturing operation while ensuring sufficient productivity (throughput), it is necessary to purge the optical path space with a high purity inert gas so that the impurity concentration is several ppm or less. As described above, the exposure apparatus using vacuum ultraviolet light can transfer a finer light-shielding pattern (circuit pattern), but is not easy to handle because it is necessary to eliminate the light-absorbing substance.

In particular, the high-purity purge as described above is not easy in the space between the optical element at the lowermost end of the projection optical system and the wafer. this is,
1. If the productivity (throughput), which is important in semiconductor manufacturing equipment, is not reduced, it is not easy to seal the space between the optical element at the lowest end of the projection optical system and the wafer (mixing of outside air into the space). Reduction is not easy).

  2. Since the exposure of the wafer is performed by repeating the step-and-repeat operation, the mechanism around the wafer stage is complicated.

3. If high-purity purge gas (high-purity inert gas) leaks from the local purge mechanism, the error given to the measurement interferometer becomes a level that cannot be ignored.
This is the reason.

  If the wafer stage is installed in a sealed space by providing a partition wall on the outer periphery of the wafer stage, high-purity purge is easy. However, since it takes time to take in and out the wafer on which the semiconductor circuit is to be printed, the productivity (throughput) of the exposure apparatus is reduced, which is not a preferable countermeasure.

In exposure apparatuses using vacuum ultraviolet light (for example, F ₂ laser light), not only absorption of exposure light by organic substances and Si compounds as before, but also absorption of exposure light by O ₂ , H ₂ O molecules, etc. is a problem. It becomes. Also, the amount of absorption is so large that it cannot be compared with an exposure apparatus using a conventional KrF excimer laser or ArF excimer laser.

  For this reason, the optical path space of the exposure light needs to be purged to a ppm level or less with a high purity inert gas.

  However, purging in a narrow space between the optical element at the lowermost end of the projection optical system and the wafer is not easy because of the above reasons, and is particularly problematic. Further, the degassing (resist releasing gas) released from the resist is mainly composed of an organic compound, a Si compound, etc., and is directly subjected to an exposure light (photo CVD reaction) to directly project optical systems. This causes the surface of the optical element at the lowermost end to become cloudy (causes a decrease in illuminance), which is a serious problem.

  For this reason, the following local purge mechanism has been proposed.

A perforated plate (guide plate) is installed between the optical element at the lowest end of the projection optical system and the wafer, and gas is supplied from an arbitrary upper direction of the wafer, while gas is exhausted from the opposite direction. (Note that if exhaust is not performed from the opposing position, a strong downflow occurs in the hole of the guide plate, but as a bounce, an upflow of a gas flow containing a large amount of the resist emission gas component may occur.)
As a result, the space (local purge space) through which the exposure light passes between the optical element at the lowest end of the projection optical system and the wafer can be filled with high-purity gas.

  By providing the local purge mechanism, most of the problems described above are solved.

  However, as a first problem, even if the amount of arrival of the resist emission gas to the optical element surface at the lowermost end of the projection optical system can be greatly reduced, the arrival of the resist emission gas to the optical element surface If the amount is not uniform and varies, this may cause uneven illumination.

  As a second problem, a pipe is usually used for supplying and exhausting high-purity gas. However, if this pipe is directly connected to the local purge space, the gas flow near the inlet / outlet of the pipe is disturbed, and the purge gas in the local purge space The uniformity of the flow (distribution of the flow velocity vector) decreases, and the distribution of the amount of the resist emission gas reaching the surface of the optical element becomes uneven. This may cause illuminance unevenness as described above.

  There is no doubt about the effectiveness of the local purge mechanism, but it is desired to improve the degree of completeness and reduce the two problems.

  The present invention has been made in view of the above circumstances, and provides an exposure method, an electronic device manufacturing method using the exposure method, and an exposure apparatus that can uniformize the flow of purge gas in the local purge space. The purpose is to do.

An exposure method of the present invention that achieves the above object is an exposure method for exposing and transferring a predetermined pattern onto a substrate to be exposed (230) via a projection optical system (150), the projection optical system, the substrate to be exposed, A transmissive fluid that transmits the exposure light is supplied to a space (181) that includes the optical path of the exposure light, and a fluid that includes the transmissive fluid is discharged from the space, and the optical path of the exposure light is included at a predetermined interval. At least one of the supply direction of the permeable fluid to the space or the discharge direction of the fluid containing the permeable fluid is changed.

  According to the exposure method of the present invention, the distribution of the amount of arrival of the resist emission gas to the optical element surface at the lowest end of the projection optical system can be made substantially uniform, and unevenness of exposure light intensity (irradiance unevenness) can be achieved. It can be made as small as possible and almost negligible. Thereby, desired exposure performance can be maintained over a long period of time.

  The exposure method of the present invention has at least two openings (183, 184) that switch between a supply port that supplies the permeable fluid to the space and a discharge port that discharges the fluid containing the permeable fluid from the space. Then, at least one of the supply direction of the permeable fluid or the discharge direction of the fluid containing the permeable fluid is changed by alternately switching the at least two openings to the supply port and the discharge port. Preferably, it is done.

  In addition, one of the at least two openings that is set as the supply port is set as the discharge port after a predetermined time has elapsed, and the one of the at least two openings is set as the discharge port. The other opening is preferably set to the supply port after a predetermined time has elapsed.

  In addition, at least one of the at least two openings (183, 184) is equipped with a fluid equalization mechanism (260) so that the permeable fluid or the fluid containing the permeable fluid in the space flows. Is preferably made uniform. This makes it possible to make the distribution of the amount of arrival of the resist emission gas reaching the surface of the optical element at the lowest end of the projection optical system substantially uniform, and to make the velocity distribution of the fluid flowing in the space including the optical path of the exposure light uniform. The exposure light intensity unevenness (illuminance unevenness) can be further reduced to a level that can be almost ignored, and desired exposure performance can be maintained over a long period of time. .

  The permeable fluid is preferably nitrogen gas or a rare gas.

  Another exposure method of the present invention is an exposure method in which a predetermined pattern is exposed and transferred onto a substrate to be exposed (230) via a projection optical system (150), and the projection optical system and the substrate to be exposed are exposed. A permeable fluid that transmits the exposure light is supplied to the space (181) including the optical path of the exposure light through the supply port, and the fluid containing the transmissive fluid is discharged from the space through the discharge port. Further, at least one of the supply port and the discharge port is equipped with a fluid homogenization mechanism (260), and the flow of the fluid containing the permeable fluid or the permeable fluid in the space is made uniform.

  According to another exposure method of the present invention, the velocity distribution of the fluid flowing in the space including the optical path of the exposure light between the projection optical system and the substrate to be exposed can be made uniform, and the exposure light intensity unevenness (illuminance) (Unevenness) can be reduced as much as possible and can be almost ignored. Thereby, desired exposure performance can be maintained over a long period of time.

In another exposure method of the present invention, the uniformizing mechanism (260) includes:
A plate member (261), and when the fluid is supplied into the space, the fluid collides with the plate member and is supplied into the space in a diverted state; or the fluid is supplied from the space. When the fluid is discharged, the fluid collides with the plate member and is discharged in a state of being once divided.
A slit (262), and when the fluid is supplied into the space, the fluid is supplied into the space in a state of being shunted by the slit, or when the fluid is discharged from the space, Allowing fluid to drain through the slit;
When the fluid is supplied into the space, the fluid is supplied into the space after being passed through the mesh, or when the fluid is discharged from the space. Allowing fluid to drain through the mesh;
A particle filter (264) is provided, and when the fluid is supplied into the space, the fluid is supplied into the space after passing through the particle filter, or the fluid is discharged from the space. Allowing the fluid to drain through the particle filter;
When the fluid is supplied into the space, the fluid is supplied into the space after passing through the porous body, or when the fluid is discharged from the space. To be discharged through the porous body,
Alternatively, a dividing path (265) that divides the inside into a plurality of flow paths is provided, and when the fluid is supplied into the space, the fluid flows into the space after passing through the dividing path. It is preferable that the fluid is supplied or discharged from the space after passing through the dividing path and flowing into the discharge port.

  The method for manufacturing an electronic device according to the present invention is a method for manufacturing an electronic device in which a predetermined pattern is exposed and transferred onto a substrate to be exposed via a projection optical system, and the exposure method according to any one of claims 1 to 11. To expose the substrate to be exposed.

  The exposure apparatus of the present invention is an exposure apparatus (100) that exposes and transfers a predetermined pattern onto a substrate (230) to be exposed via a projection optical system (150), between the projection optical system and the substrate to be exposed. A means (203) for supplying a transmissive fluid that transmits the exposure light to a space (181) that includes the optical path of the exposure light, a means (204) for discharging the fluid containing the transmissive fluid from the space, It is equipped with means (215, 216) for changing at least one of the supply direction of the permeable fluid to the space including the optical path of the exposure light and the discharge direction of the fluid containing the permeable fluid at intervals.

  According to the exposure apparatus of the present invention, with a simple configuration in which at least one of the supply direction of the permeable fluid or the discharge direction of the fluid containing the permeable fluid is changed, the resist emission gas is at the lowermost end of the projection optical system. The distribution of the amount reaching the element surface can be made substantially uniform, and the exposure light intensity unevenness (illuminance unevenness) can be made as small as possible and almost negligible. Thereby, desired exposure performance can be maintained over a long period of time.

  Another exposure apparatus of the present invention is an exposure apparatus (100) that exposes and transfers a predetermined pattern onto a substrate (230) to be exposed via a projection optical system (150), the projection optical system and the substrate to be exposed. Means (203) for supplying a transmissive fluid that transmits the exposure light to a space (181) including an optical path of the exposure light between the two through a supply port (183, 184), and a discharge port (184, 184). 183) is provided with means (204) for discharging the fluid containing the permeable fluid from the space through the space, and at least one of the supply port and the discharge port is equipped with a fluid equalization mechanism (260), so that the permeability in the space can be obtained. It is characterized in that the flow of fluid including fluid or permeable fluid is made uniform.

  According to another exposure apparatus of the present invention, the velocity distribution of the fluid flowing in the space including the optical path of the exposure light between the projection optical system and the substrate to be exposed can be made uniform, and the exposure light intensity unevenness (illuminance) (Unevenness) can be reduced as much as possible and can be almost ignored. Thereby, desired exposure performance can be maintained over a long period of time.

According to the exposure method of the present invention described in claim 1, at least one of the supply direction of the permeable fluid to the space including the optical path of the exposure light or the discharge direction of the fluid containing the transmissive fluid is changed at a predetermined interval. The distribution of the amount of the resist emission gas that reaches the optical element surface at the lowest end of the projection optical system can be made substantially uniform, and the exposure light intensity unevenness (illuminance unevenness) can be made as small as possible and almost ignored. To the extent that can be done. Thereby, desired exposure performance can be maintained over a long period of time.

  According to another exposure method of the present invention as set forth in claim 6, at least one of the supply port and the discharge port of the permeable fluid is equipped with a fluid equalizing mechanism, so that the permeable fluid or the permeability in the space is provided. Since the flow of the fluid including the fluid is made uniform, the velocity distribution of the fluid flowing in the space including the optical path of the exposure light can be made uniform, and the exposure light intensity unevenness (illuminance unevenness) is reduced as much as possible. It can be negligible. Thereby, desired exposure performance can be maintained over a long period of time.

  According to the electronic device manufacturing method of the present invention described in claim 13, the substrate to be exposed is exposed using the exposure method according to any one of claims 1 to 12. Throughput can be increased to increase productivity, and yield can be improved.

  According to the exposure apparatus of the present invention as set forth in claim 14, at least one of a supply direction of the permeable fluid to a space including the optical path of the exposure light and a discharge direction of the fluid containing the permeable fluid are changed at a predetermined interval. With a simple configuration, the distribution of the arrival amount of the resist emission gas reaching the surface of the optical element at the lowest end of the projection optical system can be made substantially uniform with a simple configuration, and the exposure light intensity unevenness (illuminance) (Unevenness) can be reduced as much as possible and can be almost ignored. Thereby, desired exposure performance can be maintained over a long period of time.

  According to another exposure apparatus of the present invention as set forth in claim 19, at least one of the fluid supply port and the fluid discharge port is equipped with a fluid homogenizing mechanism so that the permeable fluid or the permeable fluid in the space is supplied. Since the flow of the contained fluid is made uniform, the exposure light intensity unevenness (illuminance unevenness) can be reduced as much as possible and can be almost ignored. Thereby, desired exposure performance can be maintained over a long period of time.

  Embodiments of an exposure method, an electronic device manufacturing method using the exposure method, and an exposure apparatus according to the present invention will be described below with reference to FIGS.

  FIG. 1 is an overall configuration diagram showing a first embodiment of an exposure apparatus of the present invention, and FIG. 2 is installed in a space including an optical path of exposure light between the projection optical system of the exposure apparatus of FIG. FIG. 3 is a side sectional view showing the flow of fluid in the local fluid supply / discharge portion shown in FIG. 2, and FIG. 3 is a side sectional view similar to FIG. 3 showing a case where the flow direction of the fluid shown in FIG. 3 is changed, and FIGS. 5 (a) to 5 (c) and FIGS. 6 (a) to 6 (c) are local fluid supply / discharge of FIG. It is a perspective view of the fluid equalization mechanism arrange | positioned at a part.

  First, the overall configuration and operation of the exposure apparatus of the first embodiment will be described with reference to FIG.

In the first embodiment, the present invention will be described by exemplifying a step-and-scan type projection exposure apparatus using F ₂ laser light as an exposure beam.

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.

  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.

The light source 110 is an F ₂ laser that generates pulsed laser light having a wavelength of 157 nm in the vacuum ultraviolet region. The light beam emitted from the light source 110 is incident on the illumination optical system 120.

  The illumination optical system 120 performs processing such as shaping of the light beam emitted from the light source 110 and equalization of illuminance, and irradiates the processed exposure light onto the reticle (R) 220 on which a pattern to be transferred is formed.

  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. A beam shaping optical system 123 for shaping the light beam, a fly-eye lens 124 as an optical integrator for adjusting the light quantity distribution of the exposure light, and setting the light quantity distribution of the exposure light in a circular shape, a plurality of eccentric regions, an annular shape, 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.

  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 in conjunction with the control of the output energy of the light beam in the light source 110.

  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.

  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.

  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.

  Reticle blind 129 is arranged 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 so as to define 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 in 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.

The exposure light EL that has passed through the reticle blind 129 passes through the relay lens 130 and the mirror 13.
1 and the condenser lens system 132 to enter the reticle operation unit 140 to illuminate a predetermined area on the pattern surface of the reticle 220.

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 F ₂ laser light. Etc.) or a lighting system chamber 133 filled with a mixed gas such as helium or nitrogen.

  The illumination system chamber 133 is connected to the inert gas recovery device 204 via the valve 209 and is connected to the inert gas supply device 203 via the 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.

  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 to 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.

  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.

  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. The inert gas is supplied into the reticle chamber 142 so that the pressure is about 1 to 10% higher than the atmospheric pressure.

  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.

In this embodiment, since the exposure light EL is F ₂ laser light, optical glass materials with good transmittance are meteorite (CaF ₂ ), quartz glass doped with fluorine or hydrogen, and magnesium fluoride (MgF _2). ) Etc. Therefore, in the case where the projection optical system 150 includes only a refractive optical member and a desired imaging characteristic such as a chromatic aberration characteristic cannot be obtained, the projection optical system 150 is a catadioptric system that combines a refractive optical member and a reflecting mirror. It consists of.

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 at 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.

  The lens barrel PK is mounted and fixed to a body frame (not shown) of the exposure apparatus via a flange (not shown) 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. Accordingly, 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 The inert gas is supplied into the barrel PK so that the pressure is about 1 to 10% higher than the atmospheric pressure.

  The wafer operation unit 160 holds the 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.

  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.

  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. And a wafer holder that is supported on the adjustment stage and sucks and holds the wafer 230 by a vacuum suction force from a suction hole formed on the surface, and is carried by the wafer loader unit 164. The mounted wafer 230 is held on the wafer holder in a desired posture and subjected to exposure.

  The laser interferometer system 162 has at least five measurement axes, and irradiates a reflection surface formed on the adjustment stage with a laser beam, and position information of the wafer stage in the X and Y directions, and the 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.

  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.

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.

  The local gas supply / discharge unit (local fluid supply / discharge unit) 180 is a space (including an optical path space of exposure light between the optical member at the tip of the projection optical system 150 and the wafer 230 held by the wafer operation unit 160 ( The light-absorbing substance in the specific space 181 is eliminated by flowing an inert gas into the specific space 181 from a predetermined direction. This also suppresses the outgas generated from the resist of the wafer 230 from adhering to the optical member at the tip.

  The detailed configuration of the local gas supply / discharge unit 180 will be described later with reference to FIGS.

  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, an inert gas supply device 203, and an inert gas recovery device 204.

  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.

  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.

The inert gas supply device 203 is F ₂ laser light for the illumination system chamber 133 of the illumination optical system 120, the reticle chamber 142 of the reticle operation unit 140, the lens barrel PK of the projection optical system 150, and the local gas supply / discharge unit 180. An inert gas with little energy absorption is supplied to the exposure light EL.

  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.

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) are used as the light-absorbing material of the exposure light EL. ₂ O), carbon monoxide (CO), carbon dioxide (carbon dioxide: CO ₂ ), organic matter, halides, and the like. On the other hand, as a gas that hardly absorbs energy and 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.

  In this embodiment mode, nitrogen gas is supplied as the inert gas (permeable gas) supplied by the inert gas supply device 203.

  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.

  Therefore, when it is desired to 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, the helium gas should be used as an inert gas, although the cost increases. Is desirable.

  The inert gas recovery device 204 is a portion 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, the reticle chamber 142 of the reticle operation unit 140, and the projection optical system. This is a vacuum pump that exhausts the 150 barrels PK and the local gas supply / discharge unit 180.

  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 PK 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.

  In addition, for the local gas supply / discharge unit 180, the inert gas recovery device 204 continues to apply a vacuum suction force through the valves 213 and 214 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.

  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.

  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.

  Next, the local gas supply / discharge unit 180 which is a characteristic part of the exposure apparatus of the present invention will be described in detail with reference to FIGS.

As described above, the local gas supply / exhaust unit 180 is located between the projection optical system 150 and the wafer 230, that is, among the optical members constituting the projection optical system 150, the optical tip at the end disposed closest to the wafer 230. In order to eliminate the light-absorbing substance from the optical path through which the exposure light EL passes between the member 151 and the wafer 230, and to prevent the outgas generated from the resist portion of the wafer 230 from adhering to the optical member 151 at the front end, This is a mechanism for flowing an inert gas into a specific space 181 between the optical member 151 and the wafer 230.

  As shown in FIGS. 2 to 4, the local gas supply / discharge unit 180 exhausts an inert gas supply port that supplies an inert gas to the specific space 181 and a gas containing the supplied inert gas. Two openings 183 and 184 having the same structure that switches to the exhaust port are provided. Further, the local gas discharge unit 180 is disposed on the bottom surface 191 outside the openings 183 and 184 with respect to the optical axis of the exposure light EL, and on the bottom surface 191 facing the wafer, between the bottom surface 191 and the wafer 230. A surrounding exhaust groove (suction port) 186 for sucking gas in the space 182 is provided.

  The openings 183 and 184 that switch to the inert gas supply port or the exhaust port are provided opposite to the scanning direction of the exposure apparatus 100 across the optical path of the exposure light EL. In addition, it is not limited to arrangement | positioning of such opening part 183,184, For example, you may provide opening part 183,184 facing the direction orthogonal to a scanning direction.

  The bottom surface portion 191 is disposed in parallel with the surface of the wafer 230, and a rectangular opening 191a is formed at the center portion thereof in accordance with the optical path of the exposure light EL and the AF optical path.

  The opening 183 is connected to the inert gas supply device 203 or the inert gas recovery device 204 via the inert gas supply / exhaust pipe 196, the opening / closing valve 208 and the switching valve 215.

  The opening 184 is connected to the inert gas supply device 203 or the inert gas recovery device 204 via the inert gas supply / exhaust pipe 197, the opening / closing valve 212 and the switching valve 216.

  The switching valves 215 and 216 are, for example, three-way valves, and the openings 183 and 184 are connected to the inert gas supply device 203 side and the inert gas recovery device 204 side at predetermined intervals by an electric signal from a control unit (not shown). When the switching valve 215 switches the opening 183 to the inert gas supply device 203 side, the switching valve 216 switches the opening 184 to the inert gas recovery device 204 side, and the switching valve 215 opens the opening. When 183 is switched to the inert gas recovery device 204 side, the switching valve 216 is controlled to switch the opening 184 to the inert gas supply device 203 side. Both the openings 183 and 184 are not switched to the inert gas supply device 203 side, or neither of the openings 183 and 184 is switched to the inert gas recovery device 204 side.

  The interval at which the switching valves 215 and 216 are switched is, for example, every time the wafer 230 is replaced (every wafer), every time a plurality of wafers 230 are processed (every lot), or every periodic maintenance. In addition, the length of time for switching, for example, the length of time for switching the opening 183 (184) to the inert gas supply device 203 side and the length of time for switching to the inert gas recovery device 204 side must be exactly the same time. There is no need to be almost the same.

  Two switching valves 215 may be equipped with two normal stop valves instead of the three-way valve. Further, the switching valve 216 may be equipped with two normal stop valves instead of the three-way valve.

  The three-way valve and stop valve can be easily remotely controlled by an electrical signal, and the effect on the cost increase of the apparatus is small.

In the state shown in FIG. 3, the opening 183 is connected to the inert gas supply device 203 side via the switching valve 215, and the inert gas blows out from the opening 183 from the inert gas supply device 203 and is exposed. It flows in the direction of the opening 184 across the optical path of the light EL. At this time, the opening 184 facing the opening 183 is connected to the inert gas recovery device 204 side via the switching valve 216, and includes the inert gas present in the specific space 181 including the optical path of the exposure light EL. The gas is sucked by the suction force acting on the opening 184 through the switching valve 216, the opening / closing valve 212 and the inert gas supply / exhaust pipe 197, and is exhausted outside the chamber 201 in which the exposure apparatus 100 is installed.

  In the state shown in FIG. 4, the opening 184 is connected to the inert gas supply device 203 side via the switching valve 216, and the inert gas blows out from the opening 184 from the inert gas supply device 203. The exposure light EL is caused to flow in the direction of the opening 183 across the optical path of the exposure light EL. At this time, the opening 183 facing the opening 184 is connected to the inert gas recovery device 204 side via the switching valve 215 and includes the inert gas present in the specific space 181 including the optical path of the exposure light EL. The gas is sucked by the suction force acting on the opening 183 via the switching valve 215, the opening / closing valve 208 and the inert gas supply / exhaust pipe 196, and is exhausted outside the chamber 201 in which the exposure apparatus 100 is installed.

  In order to close the gap between the front end surface of the projection optical system 150 and the upper surface of the local gas supply / discharge unit 180, a film is formed between the upper surface of the local gas supply / discharge unit 180 and the peripheral edge of the front end surface of the projection optical system 150. A sealing portion 195 is provided. This film-like sealing part 195 is a film-like member having high airtightness. The configuration for closing the gap is not limited to a film-like member having high airtightness but may be another member. For example, an elastic member may be used.

  Thereby, the gas containing the inert gas in the specific space 181 from the gap between the front end surface of the projection optical system 150 and the upper surface of the local gas supply / exhaust unit 180 (the upper surface of the opening 183 and the upper surface of the opening 184). However, it is possible to prevent leakage to the outside of the specific space 181, that is, around the wafer operation unit 160 in the exposure apparatus 100.

  The bottom surface portion of the opening 183 and the bottom surface portion of the exhaust port portion 184 are formed integrally with a series of bottom surface portions 191 that define the bottom surface of the local gas supply / discharge portion 180.

  The local gas supply / discharge unit 180 is projected by the film-like sealing unit 195 so that the bottom surface portion 191 of the local gas supply / discharge unit 180 is not in contact with the wafer at a predetermined interval. It is attached to the tip face of the system 150.

  Further, the local gas supply / discharge unit 180 has a peripheral surface so as to surround the specific space 181 outside the specific space 181 of the bottom surface portion 191 of the local gas supply / discharge unit 180 facing the wafer 230 at a predetermined distance. An exhaust groove 186 is provided.

  As shown in FIG. 2, the surrounding exhaust groove 186 is connected to exhaust pipes 198 and 199 at four locations, and each exhaust pipe 198 and 199 is connected to the inert gas recovery device 204 via the corresponding valves 213 and 214. Has been. As a result, the gas existing in the gap between the local gas supply / discharge unit 180 and the wafer 230 acts on the peripheral exhaust groove 186 from the inert gas recovery device 204 via the valves 213 and 214 and the exhaust pipes 198 and 199. Is sucked by the suction force and exhausted to the outside of the chamber 201.

The surrounding exhaust groove 186 exhausts a larger amount of gas than the difference between the supply amount of the ineffective gas from the opening 183 (opening 184) and the total exhaust amount of the gas from the opening 184 (opening 183). To do. In this way, even if the amount of inert gas supplied from the opening 183 (opening 184) is larger than the amount of gas discharged from the opening 184 (opening 183), the surrounding exhaust groove 186
Including the exhaust amount of the gas from the opening 184 and the surrounding exhaust groove 186, the total exhaust amount of the gas is larger than the supply amount of the inert gas from the opening 183 (opening 184). As a result, since the surrounding exhaust groove 186 is disposed so as to surround the specific space 181, the peripheral exhaust groove 186 is added to the gas containing the inert gas from the direction of the specific space 181 as shown in FIG. 3 or 4. Then, the air from the outside of the local gas supply / discharge unit 180 is also sucked together. That is, a gas flow toward the peripheral exhaust groove 186 is generated from the specific space 181 and from the outside. As a result, outside air is prevented from entering the specific space 181 and gas in the specific space 181 is also prevented from leaking into the external space.

  As shown in FIG. 2, the peripheral exhaust groove 186 has a notch 186 a at a location of an inert gas supply / exhaust pipe 196 connected to the opening 183 and an inert gas supply / exhaust pipe 197 connected to the opening 184. In addition, there is a notch 186b at the glass windows 250 and 250 for guiding AF light on a line orthogonal to the line connecting the inert gas supply / exhaust pipe 196 and the inert gas supply / exhaust pipe 197 to the exposure area. Since the cutout 186b is larger than the cutout 186a, it causes the outside air to flow into the local gas supply / discharge unit 180 through the cutout 186b. For this reason, the exhaust pipes 198 and 199 connected to the peripheral exhaust groove 186 are disposed on both sides of the notch 186b (glass window 250).

  Next, an embodiment of an exposure method and an electronic device manufacturing method by the exposure apparatus 100 will be described.

  During the exposure process for exposing the pattern of the reticle 220 onto the wafer 230, for example, as shown in FIG. 3, the opening 183 is switched to the inert gas supply device 203 side by the switching valve 215, and the opening 184 is switched by the switching valve 216. Is switched to the inert gas recovery device 204 side.

  As a result, the inert gas supplied from the inert gas supply device 203 through the valve 208 and the inert gas supply / exhaust pipe 196 is blown out from the opening 183 at a predetermined speed, and the optical member 151 at the tip and the wafer 230 are exposed. It is supplied to a specific space 181 including the optical path of the exposure light EL between the regions.

  The inert gas supplied to the specific space 181 is sucked through the opening 184 disposed to face the optical path of the exposure light EL, and passes through the inert gas supply / exhaust pipe 197 and the inert gas recovery device 204. The air is exhausted outside the chamber 201.

  Air or the like containing the light-absorbing substance in the specific space 181 is substantially exhausted to the outside of the exposure apparatus 100 along with the flow of the inert gas from the opening 183 toward the opening 184, and the specific space 181 is inactive. The gas is full.

  Next, as shown in FIG. 4, the switching valve 215 switches the opening 183 to the inert gas recovery device 204 side, and the switching valve 216 switches the opening 184 to the inert gas supply device 203 side.

  As a result, the inert gas supplied from the inert gas supply device 203 through the valve 212 and the inert gas supply / exhaust pipe 197 is blown out from the opening 184 at a predetermined speed, and exposure of the optical member 151 at the front end and the wafer 230 is performed. It is supplied to a specific space 181 including the optical path of the exposure light EL between the regions.

The inert gas supplied to the specific space 181 is sucked through the opening 183 arranged to face the optical path of the exposure light EL, and the inert gas supply / exhaust pipe 196 and the inert gas recovery device 2 are sucked.
The air is exhausted out of the chamber 201 through 04.

  The air containing the light-absorbing substance in the specific space 181 is substantially exhausted to the outside of the exposure apparatus 100 along with the flow of the inert gas from the opening 184 opposite to the previous one toward the opening 183. The interior of 181 is filled with an inert gas.

  In the specific space 181, as shown in FIG. 3, the optical member 151 and the wafer from the opening 183 toward the opening 184 and as shown in FIG. 4 from the opening 184 toward the opening 183, that is, the tip. An inert gas flow is formed in a direction parallel to the surface of 230 and perpendicular to the optical path of the exposure light EL.

  As a result, the outgas generated from the resist in the exposure region of the wafer 230 is forcibly forced by the flow of the inert gas while being diffused in the optical axis direction of the exposure light EL, that is, in the direction of the optical member 151 at the tip. Alternatively, the air flows in the direction of the opening 183) and is exhausted from the opening 184 (or the opening 183).

  By changing the direction in which the inert gas flows in a direction from the opening 183 to the opening 184 and from the opening 184 to the opening 183 with a predetermined interval, the resist in the exposure region of the wafer 230 is changed. Even if the generated outgas diffuses into the specific space 181, the distribution amount of the outgas reaching the optical member 151 can be made substantially uniform, and exposure light intensity unevenness (illuminance unevenness) can be reduced as much as possible. Can be negligible. Thereby, desired exposure performance can be maintained over a long period of time.

  The amount of the inert gas supplied from the opening 183 (or the opening 184) is larger than the amount of gas exhausted from the opening 184 (or the opening 183), and the upper surface of the local gas supply / discharge unit 180 Since the projection optical system 150 is sealed with a film-shaped sealing unit 195, the excess inert gas supplied to the specific space 181 is formed in the gap between the local gas supply / discharge unit 180 and the wafer 230. It flows into the space 182 and flows out of the specific space 181.

  On the other hand, in the space 182 of the gap, gas is exhausted from a peripheral exhaust groove 186 provided over the entire area so as to surround the specific space 181. Therefore, the gas containing the inert gas flowing from the specific space 181 to the space 182 is sucked by the surrounding exhaust groove 186 and finally exhausted out of the chamber 201.

  Further, the amount of gas exhausted in the peripheral exhaust groove 186 is larger than the amount of gas flowing out from the specific space 181 to the space 182 in the gap (the space between the local gas supply / discharge unit 180 and the wafer 230). In the exhaust groove 186, together with the gas flowing out from the specific space 181, the air around the wafer operation unit 160 outside the specific space 181 is also sucked and exhausted. Therefore, in the space 182 in the gap outside the peripheral exhaust groove 186, an air flow from the outside toward the peripheral exhaust groove 186 is formed.

  As a result, an air flow is generated from both the specific space 181 and the outside with respect to the surrounding exhaust groove 186, preventing leakage of gas in the specific space 181 to the periphery of the wafer operation unit 160, and air outside the specific space 181. Both prevention of intrusion into the specific space 181 is achieved.

  The electronic device performs an exposure process for exposing the pattern of the reticle 220 onto the wafer 230 by the exposure apparatus 100 of the above-described embodiment, and then performs a device assembly step (including a dicing process, a bonding process, a package process, etc.), and an inspection step. It is manufactured through.

  As described above, in the exposure apparatus 100 of the present embodiment, the exposure method using the exposure apparatus 100, and the manufacturing method of the electronic device, an opening is formed in the specific space 181 that is the optical path of the exposure light EL irradiated onto the wafer 230. The inert gas supplied from the portion 183 (or the opening 184) is filled, and a gas such as air containing a light-absorbing substance is exhausted from the specific space 181.

  Therefore, the energy of the exposure light EL is absorbed by the light-absorbing substance and the light amount of the exposure light EL is prevented from decreasing, and the illuminance reduction of the exposure light EL on the wafer surface during exposure is suppressed, improving the throughput of exposure processing. Can be made.

  In addition, a peripheral exhaust groove 186 is disposed so as to surround the specific space 181 and the space 182 between the local gas supply / discharge unit 180 around the specific space 181 and the wafer 230, and the peripheral exhaust groove 186 is inactive from the specific space 181. Both the gas and the air from the periphery of the wafer operation unit 160 outside the specific space 181 are sucked and exhausted. Accordingly, an air flow is generated in the direction of the surrounding exhaust groove 186 from the inside of the specific space 181 and from the outside of the specific space 181, and the air outside the specific space 181 enters the specific space 181 and the space 182, and the specific space 181. In addition, the inert gas in the space 182 is prevented from leaking around the wafer operation unit 160. As a result, the local inert gas purge of only the specific space 181 can be appropriately performed.

  As a result, it is possible to reduce the outgas from diffusing into the specific space 181 and to reduce the outgas reaching the projection optical system 150 and adhering to the optical member 151 at the tip. As a result, it is possible to prevent the optical member 151 at the tip from becoming dirty and reduce the transmittance, to suppress a decrease in the illuminance of the exposure light EL on the wafer surface during exposure, and to improve the throughput of the exposure process.

  Further, since the distribution amount of the outgas reaching the optical member 151 at the tip can be made substantially uniform and unevenness in illuminance can be suppressed, the exposure process can be appropriately performed with high accuracy and defective electrons can be obtained. The device can be prevented from being generated and the yield can be improved.

  Further, in the exposure apparatus 100 of the present embodiment, it is not necessary to increase the amount of inert gas supplied to the specific space 181 of the local gas supply / discharge unit 180 in order to obtain such an effect. Therefore, an increase in the consumption of inert gas can be suppressed and an increase in running cost can be prevented.

  In addition, since the supply of an inert gas and the manufacture of an efficient electronic device can be performed, the lifetime of the exposure apparatus can be extended.

  Next, a second embodiment of the exposure apparatus of the present invention will be described.

  In the exposure apparatus of the second embodiment, the fluid equalization mechanism 260 (FIGS. 5A to 5C and FIGS. 6A to 6C) is provided in the opening 183 and the opening 184 of the local fluid supply / discharge unit 180. Is equipped).

  The exposure apparatus of the second embodiment has the same configuration as the exposure apparatus of the first embodiment except that the fluid uniformizing mechanism 260 is provided in the openings 183 and 184.

  FIG. 5A shows an embodiment of the fluid equalizing mechanism 260. The fluid equalizing mechanism 260 is formed in a hood shape whose lateral width gradually increases from the base end connected to the inert gas supply / exhaust pipe 196 (or the inert gas supply / exhaust pipe 197) to the side facing the specific space 181. ing. About the height dimension of the fluid equalization mechanism 260, it does not change from the base end part to the side which faces the specific space 181, and is constant.

  In the fluid equalizing mechanism 260 provided in the opening 183 (or the opening 184) connected to the inert gas supply device 203 side, the gas is supplied from the inert gas supply / exhaust pipe 196 (or the inert gas supply / exhaust pipe 197). Immediately after flowing into the fluid homogenization mechanism 260, the flow rate of the inert gas is high in the portion on the extended line of the inert gas supply / exhaust pipe 196 (or the inert gas supply / exhaust pipe 197), and otherwise. In part, it becomes slow as it leaves | separates from an extension line, and the velocity distribution of an inert gas is non-uniform | heterogenous. As the inert gas flows through the fluid equalization mechanism 260 toward the specific space 181, the flow rate of the portion on the extended line of the inert gas supply / exhaust pipe 196 (or the inert gas supply / exhaust pipe 197) decreases. It becomes almost the same as the flow velocity of the other parts. At the time of flowing into the specific space 181 from the opening 183 (or the opening 184) through the fluid uniformizing mechanism 260, the velocity distribution of the inert gas becomes substantially uniform. In the specific space 181, the inert gas flows from the opening 183 toward the opening 184 or from the opening 184 toward the opening 183 with a substantially uniform velocity distribution.

  In addition, in the fluid homogenization mechanism 260 provided in the opening 184 (or opening 183) connected to the inert gas recovery device 204 side, the fluid flows from the specific space 181 through the opening 184 (or opening 183). In the process of reaching the inert gas supply / exhaust pipe 197 (or the inert gas supply / exhaust pipe 196), the flow rate of the inert gas is gradually increased by the fluid equalizing mechanism 260 without abrupt change. Therefore, the flow of the inert gas is not disturbed near the opening 184 (or the opening 183), and the velocity distribution of the inert gas is kept substantially uniform.

  Thus, in the specific space 181, the inert gas velocity distribution is kept uniform not only in the portion between the opening 183 and the opening 184 but also in the vicinity of the opening 183 and in the vicinity of the opening 184. . Therefore, even for outgas generated from the resist in the exposure region of the wafer 230 carried by the flow of the inert gas, the amount of distribution reaching the optical member 151 can be made substantially uniform, and the exposure light intensity unevenness (illuminance) (Unevenness) can be reduced as much as possible and can be almost ignored. Thereby, desired exposure performance can be maintained over a long period of time.

  FIGS. 5B and 5C and FIGS. 6A, 6B, and 6C show modified examples of the fluid equalizing mechanism 260. FIG.

  In the modification shown in FIG. 5 (b), the side (opening 183 or opening 184) facing the specific space 181 of the fluid uniformizing mechanism 260 shown in FIG. A plate member 261 is arranged on the extended line of 196 (or the inert gas supply / exhaust pipe 197). The total value of the cross-sectional areas of the gaps 261a on both sides of the plate member 261 is set larger than the cross-sectional area of the inert gas supply / exhaust pipe 196 (or the inert gas supply / exhaust pipe 197).

  According to this modification, the inert gas supplied from the inert gas supply / exhaust pipe 196 (or inert gas supply / exhaust pipe 197) is converted into the inert gas supply / exhaust pipe 196 (or inert gas supply / exhaust pipe 197). After colliding with the plate member 260a on the extended line of the plate and losing the momentum (after being decelerated), it flows into the specific space 181 from the gap 261a on the left and right of the plate member 261. Thereby, the velocity distribution of the inert gas flowing into the specific space 181 becomes more uniform as compared with the fluid homogenizing mechanism 260 shown in FIG. Further, the inert gas in the specific space 181 passes through the gaps 261 a on the left and right of the plate member 261, and is discharged to the inert gas supply / exhaust pipe 197 (or the inert gas supply / exhaust pipe 196). Does not disturb the flow of active gas. Even for the outgas generated from the resist in the exposure region of the wafer 230, which is conveyed by the flow of the inert gas having a uniform velocity distribution, the amount of distribution reaching the optical member 151 can be made substantially uniform, and the exposure light intensity can be made uniform. Unevenness (irradiance unevenness) can be reduced as much as possible, and can be made almost negligible.

  In the modification shown in FIG. 5C, the slit 262 is provided over substantially the entire side (opening 183 or opening 184) facing the specific space 181 of the fluid equalizing mechanism 260 shown in FIG. 5A. . The slit 262 is set so that the vertical width thereof is sufficiently smaller than the inner diameter of the inert gas supply / exhaust pipe 196 (or the inert gas supply / exhaust pipe 197).

  According to this modification, the inert gas supplied from the inert gas supply / exhaust pipe 196 (or the inert gas supply / exhaust pipe 197) flows into the specific space 181 through the slit 262. The active gas supply / exhaust pipe 196 (or the inert gas supply / exhaust pipe 197) cannot flow into the specific space 181 only from the slit 262 on the extended line, and the inert gas supply / exhaust pipe 196 (or the inert gas supply / exhaust pipe 196). The gas supply / exhaust pipe 197) also flows into the specific space 181 from the portion of the slit 262 away from the extended line, and the velocity distribution of the inert gas flowing into the specific space 181 is shown in FIG. It becomes more uniform than the fluid equalizing mechanism 260 shown in FIG. Further, the inert gas in the specific space 181 passes through the slit 262 and is discharged to the inert gas supply / exhaust pipe 197 (or the inert gas supply / exhaust pipe 196), and does not disturb the flow of the inert gas in the specific space 181. . Even for the outgas generated from the resist in the exposure region of the wafer 230, which is conveyed by the flow of the inert gas having a uniform velocity distribution, the amount of distribution reaching the optical member 151 can be made substantially uniform, and the exposure light intensity can be made uniform. Unevenness (irradiance unevenness) can be reduced as much as possible, and can be made almost negligible.

  In the above modification, the case where the vertical widths of the slits 262 provided in the fluid equalizing mechanism 260 are the same is shown, but on the extended line of the inert gas supply / exhaust pipe 196 (or the inert gas supply / exhaust pipe 197). By reducing the vertical width of the slit 262 in the vicinity of, and increasing the vertical width of the slit 262 in other portions, the velocity distribution of the inert gas can be made more uniform.

  In the modification shown in FIG. 6A, the mesh 263 is provided on the side (opening 183 or opening 184) facing the specific space 181 of the fluid uniformizing mechanism 260 shown in FIG. This mesh 263 has a greater resistance to fluid than it looks (reduced fluid conductance), and in particular, an inert gas having a large momentum on the extended line of the inert gas supply / exhaust pipe 196 (or the inert gas supply / exhaust pipe 197). When the gas hits the mesh 263, the inert gas is scattered.

  According to this modification, the resistance of the mesh 263 to the fluid is large, and the inert gas is not only the portion of the mesh 263 on the extended line of the inert gas supply / exhaust pipe 196 (or the inert gas supply / exhaust pipe 197). From other parts, it passes through the mesh 263 and flows into the specific space 181, and the velocity distribution of the inert gas flowing into the specific space 181 shows the fluid homogenization mechanism 260 shown in FIG. It becomes more uniform than Further, the inert gas in the specific space 181 passes through the mesh 263 and is discharged to the inert gas supply / exhaust pipe 197 (or the inert gas supply / exhaust pipe 196), so that the flow of the inert gas in the specific space 181 is not disturbed. . Even for the outgas generated from the resist in the exposure region of the wafer 230, which is conveyed by the flow of the inert gas having a uniform velocity distribution, the amount of distribution reaching the optical member 151 can be made substantially uniform, and the exposure light intensity can be made uniform. Unevenness (irradiance unevenness) can be reduced as much as possible, and can be made almost negligible.

  It goes without saying that the same effect can be obtained even if a porous body is used instead of the mesh 263.

In the modification shown in FIG. 6B, the particle filter 264 is provided on the side (opening 183 or opening 184) facing the specific space 181 of the fluid uniformizing mechanism 260 shown in FIG. Similar to the mesh 263, the particle filter 264 has a greater resistance to the fluid than it looks (decreases the conductance of the fluid), and the velocity distribution of the inert gas flowing into the specific space 181 through the particle filter 264 is uniform. Make it.

  According to this modification, the flow velocity portion distribution of the inert gas that passes through the particle filter 264 and flows into the specific space 181 becomes more uniform than the fluid homogenization mechanism 260 shown in FIG. Further, the inert gas in the specific space 181 passes through the particle filter 264 and is discharged to the inert gas supply / exhaust pipe 197 (or the inert gas supply / exhaust pipe 196), thereby disturbing the flow of the inert gas in the specific space 181. Absent. Even for the outgas generated from the resist in the exposure region of the wafer 230, which is conveyed by the flow of the inert gas having a uniform velocity distribution, the amount of distribution reaching the optical member 151 can be made substantially uniform, and the exposure light intensity can be made uniform. Unevenness (irradiance unevenness) can be reduced as much as possible, and can be made almost negligible.

  The particle filter 264 can not only make the velocity distribution of the inert gas uniform, but also can remove the fine particles contained in the inert gas and significantly reduce the particle content.

  In the modified example shown in FIG. 6C, the inside of the fluid equalizing mechanism 260 shown in FIG. 5A is partitioned into a plurality of dividing paths 265, and the active gas supply / exhaust pipe 196 (or the inert gas supply / exhaust pipe 197). The inert gas supplied from the air is divided into a plurality of flows before flowing into the specific space 181, and the inert gas is supplied into the specific space 181 in a diffused state, thereby uniforming the velocity distribution of the inert gas. I have to.

  According to this modification, the velocity distribution of the inert gas supplied in a state of being diffused into the specific space 181 through each dividing path 265 is higher than that of the fluid homogenizing mechanism 260 shown in FIG. It becomes more uniform. Further, the inert gas in the specific space 181 passes through the dividing path 265 and is discharged to the inert gas supply / exhaust pipe 197 (or the inert gas supply / exhaust pipe 196), thereby disturbing the flow of the inert gas in the specific space 181. Absent. Even for the outgas generated from the resist in the exposure region of the wafer 230, which is conveyed by the flow of the inert gas having a uniform velocity distribution, the amount of distribution reaching the optical member 151 can be made substantially uniform, and the exposure light intensity can be made uniform. Unevenness (irradiance unevenness) can be reduced as much as possible, and can be made almost negligible.

  In the exposure apparatus of the second embodiment, the case where both the openings 183 and 184 are equipped with the fluid equalizing mechanism 260 is shown, but the present invention is not limited to this. At least one of the openings 183 and 184 The same effect can be achieved even if equipped on either side.

  Moreover, although the case where the fluid equalizing mechanism 260 is provided in the openings 183 and 184 that alternately switch to the supply port and the discharge port of the inert gas has been shown, the opening and the discharge port fixed to the supply port of the inert gas A fluid equalizing mechanism 260 may be provided in at least one of the openings fixed to the. Even in this case, the velocity distribution of the inert gas in the specific space 181 is made uniform by the fluid homogenizing mechanism 260, and the optical member is also used for outgas generated from the resist in the exposure region of the wafer 230 that is carried by the inert gas. Of course, the amount of distribution reaching 151 can be made substantially uniform, the exposure light intensity unevenness (illuminance unevenness) can be made as small as possible, and almost negligible.

About the exposure method by the exposure apparatus of the said 2nd Embodiment, and the manufacturing method of an electronic device, it carries out similarly to the case of the exposure apparatus of the said 1st embodiment. When the exposure apparatus of the second embodiment is used, the distribution of the arrival amount of the resist emission gas reaching the surface of the optical element at the lowest end of the projection optical system can be made substantially uniform, and the specific space 181 can be obtained. In combination with the fact that the velocity distribution of the inert gas flowing through the substrate can be made uniform, the exposure light intensity unevenness (illuminance unevenness) can be further reduced to a level that can be almost neglected, and desired over a long period of time. The exposure performance can be maintained and the yield can be improved.

  The first and second embodiments are described for facilitating understanding of the present invention, and do not limit the present invention. Each element disclosed in the present embodiment includes all design changes and equivalents belonging to the technical scope of the present invention, and various suitable modifications are possible.

  In the present embodiment, the case where the pair of opening portions 183 and 184 facing each other, which are switched to the supply port and the discharge port of the inert gas, is shown, but the present invention is not limited to this. A plurality of may be provided.

  In the present embodiment, the fluid uniformizing mechanism 260 illustrated in FIGS. 5 to 6 is exemplified, but the present invention is not limited to this, and the point is that the inert gas in the specific space 181 is important. Any device that uniformizes the velocity distribution may be used.

  In the present embodiment, the illumination optical system 120 is configured such that all the components of the beam matching unit 121 to the condenser lens system 132 are accommodated in one chamber 133. However, for example, the beam matching unit 121 to the beam splitter 126 are accommodated in one chamber as a first illumination optical system, and are provided on a stand different from a column on which an exposure apparatus main body such as a projection optical system is placed, and a mirror 127 to the condenser lens system 132 are accommodated in one chamber as a second illumination optical system and provided in the same column as the exposure apparatus main body, and the illumination optical system is appropriately divided and accommodated in the chamber as an exposure apparatus. You may make it mount.

In the present embodiment, the present invention has been described by exemplifying an exposure apparatus that uses an F ₂ laser as a light source. However, the present invention has been described with reference to an exposure apparatus that uses a high-pressure mercury lamp, a KrF excimer laser, and an ArF excimer laser as a light source. Is also applicable.

  Further, in the present embodiment, the present invention has been described by exemplifying a case where an inert gas is supplied to the specific space 181. However, exposure by a so-called immersion method in which a liquid is sandwiched between the optical member at the tip and the wafer. When performing the above, for example, a predetermined liquid such as water or fluorine-based inert oil is supplied to the same method and discharged. The present invention is applicable to such a case, and it is obvious that this case is also within the scope of the present invention.

1 is an overall configuration diagram showing a first embodiment of an exposure apparatus of the present invention. FIG. 1 is a plan view of a local fluid supply / discharge unit provided in a space including the optical path of exposure light between the projection optical system of the exposure apparatus of FIG. 1 and the substrate to be exposed (plan view viewed from the optical member 151 side at the tip). It is. It is explanatory side sectional drawing which shows the flow of the fluid in the local fluid supply / discharge part shown in FIG. FIG. 4 is an explanatory side cross-sectional view similar to FIG. 3 illustrating a case where the flow direction of the fluid illustrated in FIG. 3 is changed. It is a perspective view which shows the embodiment of the fluid equalization mechanism. It is a perspective view which shows the embodiment of the fluid equalization mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Exposure apparatus 110 ... Light source 120 ... Illumination optical system 150 ... Projection optical system 160 ... Wafer operation part 180 ... Local gas supply / discharge part 181 ... Specific space 182 ... Gap space 183 ... Opening part 184 ... Opening part 186 ... Surrounding exhaust groove 191: Bottom portion 196, 197 ... Inert gas supply / discharge pipe 203: Inert gas supply device 204 ... Inert gas recovery device 216, 216 ... Switching valve 260 ... Fluid equalization mechanism 261 ... Plate member 262 ... Slit 263 ... Mesh 264 ... Particle filter 265 ... Dividing path

Claims (26)

An exposure method for exposing and transferring a predetermined pattern onto a substrate to be exposed through a projection optical system,
Supplying a transmissive fluid that transmits the exposure light to a space including an optical path of the exposure light between the projection optical system and the substrate to be exposed;
Draining the fluid containing the permeable fluid from the space;
An exposure method comprising: changing at least one of a supply direction of the permeable fluid to a space including an optical path of the exposure light or a discharge direction of the fluid containing the permeable fluid at a predetermined interval. The exposure method according to claim 1, wherein
Having at least two openings switched to a supply port for supplying the permeable fluid to the space and a discharge port for discharging a fluid containing the permeable fluid from the space;
At least one of the supply direction of the permeable fluid or the discharge direction of the fluid containing the permeable fluid is changed by alternately switching the at least two openings to the supply port and the discharge port. An exposure method characterized by the above. The exposure method according to claim 2, wherein
Of the at least two openings, one opening set as the supply port is set as the discharge port after a predetermined time, and the other of the at least two openings is set as the discharge port. The opening is set in the supply port after a predetermined time has elapsed. In the exposure method according to claim 2 or 3,
The exposure is characterized in that at least one of the at least two openings is equipped with a fluid homogenizing mechanism to equalize the flow of the permeable fluid or the fluid containing the permeable fluid in the space. Method. In the exposure method according to any one of claims 1 to 4,
An exposure method, wherein the transmissive fluid is nitrogen gas or a rare gas. An exposure method for exposing and transferring a predetermined pattern onto a substrate to be exposed through a projection optical system,
Supplying a transmissive fluid that transmits the exposure light to the space including the optical path of the exposure light between the projection optical system and the substrate to be exposed through a supply port;
Discharging the fluid containing the permeable fluid from the space through the outlet;
An exposure method, wherein a fluid uniformizing mechanism is provided in at least one of the supply port and the discharge port to uniformize a flow of the permeable fluid or the fluid containing the permeable fluid in the space. The exposure method according to claim 6, wherein
The homogenizing mechanism includes a plate member, and when the fluid is supplied into the space, the fluid collides with the plate member and is supplied into the space in a diverted state, or from within the space. An exposure method, wherein when the fluid is discharged, the fluid collides with the plate member and is discharged in a state of being once divided. The exposure method according to claim 6, wherein
When the uniformizing mechanism includes a slit and the fluid is supplied into the space, the fluid is supplied into the space in a state of being divided by the slit, or the fluid is discharged from the space. An exposure method characterized in that the fluid is discharged through the slit. The exposure method according to claim 6, wherein
When the uniformizing mechanism includes a mesh, and the fluid is supplied into the space, the fluid is supplied into the space after passing through the mesh, or the fluid is discharged from the space. An exposure method characterized in that the fluid is discharged through the mesh. The exposure method according to claim 6, wherein
When the uniformizing mechanism includes a particle filter, and the fluid is supplied into the space, the fluid passes through the particle filter and is then supplied into the space, or the fluid is discharged from the space. In the exposure method, the fluid is discharged through the particle filter. The exposure method according to claim 6, wherein
When the uniformizing mechanism includes a porous body and the fluid is supplied into the space, the fluid is supplied into the space after passing through the porous body, or the fluid is discharged from the space. In the exposure method, the fluid is discharged through the porous body. The exposure method according to claim 6, wherein
The homogenizing mechanism includes a dividing path that divides the inside into a plurality of flow paths, and when the fluid is supplied into the space, the fluid flows into the space after passing through the dividing path. An exposure method comprising: supplying or discharging the fluid from the space after passing through the dividing path and flowing into the discharge port. In an electronic device manufacturing method for exposing and transferring a predetermined pattern onto a substrate to be exposed through a projection optical system,
13. A method of manufacturing an electronic device, wherein the substrate to be exposed is exposed using the exposure method according to any one of claims 1 to 12. An exposure apparatus that exposes and transfers a predetermined pattern onto a substrate to be exposed via a projection optical system,
Means for supplying a transmissive fluid that transmits the exposure light to a space including an optical path of the exposure light between the projection optical system and the substrate to be exposed;
Means for discharging fluid containing the permeable fluid from the space;
An exposure apparatus comprising: means for changing at least one of a supply direction of the permeable fluid to a space including the optical path of the exposure light at a predetermined interval or a discharge direction of the fluid containing the permeable fluid. . The exposure apparatus according to claim 14, wherein
Having at least two openings switched to a supply port for supplying the permeable fluid to the space and a discharge port for discharging a fluid containing the permeable fluid from the space;
The means for changing at least one of the supply direction of the permeable fluid or the discharge direction of the fluid containing the permeable fluid is a means for alternately switching each of the at least two openings to the supply port and the discharge port. An exposure apparatus including the exposure apparatus. The exposure apparatus according to claim 15, wherein
The switching means sets one of the at least two openings, which is set as the supply port, as the discharge port after a lapse of a predetermined time, and sets the discharge port as the discharge port among the at least two openings. An exposure apparatus characterized in that the other set opening is set to the supply port after a predetermined time has elapsed. The exposure apparatus according to claim 15 or 16,
The exposure is characterized in that at least one of the at least two openings is equipped with a fluid homogenizing mechanism to equalize the flow of the permeable fluid or the fluid containing the permeable fluid in the space. apparatus. The exposure apparatus according to any one of claims 14 to 17,
An exposure apparatus wherein the transmissive fluid is nitrogen gas or a rare gas. An exposure apparatus that exposes and transfers a predetermined pattern onto a substrate to be exposed via a projection optical system,
Means for supplying a transmissive fluid that transmits the exposure light to a space including an optical path of exposure light between the projection optical system and the substrate to be exposed through a supply port;
Means for discharging fluid containing the permeable fluid from the space through a discharge port;
Equipped with a fluid equalizing mechanism at least one of the supply port or the discharge port,
An exposure apparatus characterized by uniformizing a flow of the permeable fluid or the fluid containing the permeable fluid in the space. The exposure apparatus according to claim 19,
The homogenizing mechanism includes a plate member, and when the fluid is supplied into the space, the fluid collides with the plate member and is supplied into the space in a diverted state, or from within the space. An exposure apparatus characterized in that when the fluid is discharged, the fluid collides with the plate member and is discharged in a state of being once divided. The exposure apparatus according to claim 19,
When the uniformizing mechanism includes a slit and the fluid is supplied into the space, the fluid is supplied into the space in a state of being divided by the slit, or the fluid is discharged from the space. An exposure apparatus characterized in that the fluid is discharged through the slit. The exposure apparatus according to claim 19,
When the uniformizing mechanism includes a mesh, and the fluid is supplied into the space, the fluid is supplied into the space after passing through the mesh, or the fluid is discharged from the space. An exposure apparatus characterized in that the fluid is discharged through the mesh. The exposure apparatus according to claim 19,
When the uniformizing mechanism includes a particle filter, and the fluid is supplied into the space, the fluid passes through the particle filter and is then supplied into the space, or the fluid is discharged from the space. An exposure apparatus characterized in that the fluid passes through the particle filter and is discharged. The exposure apparatus according to claim 19,
When the uniformizing mechanism includes a porous body, and the fluid is supplied into the space, the fluid passes through the porous body, and then is supplied into the space, or the fluid is discharged from the space. An exposure apparatus characterized in that the fluid passes through the porous body and is discharged. The exposure apparatus according to claim 19,
The homogenizing mechanism includes a dividing path that divides the inside into a plurality of flow paths, and when the fluid is supplied into the space, the fluid flows into the space after passing through the dividing path. An exposure apparatus, wherein the fluid is supplied or the fluid passes through the dividing path from the space and then flows into the discharge port to be discharged. In the exposure apparatus according to any one of claims 19 to 23,
An exposure apparatus wherein the transmissive fluid is nitrogen gas or a rare gas.

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