JP2002033267A - Method and device for exhausting, and method and device for exposure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for exhausting, as well as method and device for exposure, to remove, with a simple configuration, the gas containing light-absorbing material present in an optical-path space for precision and stable exposure process. SOLUTION: An exposure device RX comprises an exhausting device S which exhausts the light-absorbing material having such characteristics as absorbs exposure light PL present in a space SP formed between a projection optical system PL and a photosensitized plate P. The exhausting device S comprises exhausting mechanisms 1 provided at a plurality of positions between a position in the space SP which corresponds to a projection region AR by the projection optical system PL on the photosensitized board P and a position at the outer edge of the space SP, and a control device CONT which controls the exhausting mechanisms 1 for exhausting while the pressure at the outer edge is set higher relative to the position corresponding to the projection region AR.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust method and an exhaust apparatus for exhausting a predetermined gas existing in a space formed between two opposing objects, and an exposure method and an exposure apparatus.

[0002]

2. Description of the Related Art Various types of exposure apparatuses are used in the manufacture of semiconductor elements, thin-film magnetic heads, liquid crystal display elements, and the like by a photolithography process. A photomask or reticle (hereinafter, referred to as a "mask") is used. An exposure apparatus which projects an image of a formed pattern onto a substrate having a surface coated with a photosensitive agent such as a photoresist through a projection optical system is generally used. In recent years, with the miniaturization of the shape of a pattern projected on a shot region on a substrate, the exposure illumination light used (hereinafter, referred to as “exposure light”) tends to have a shorter wavelength. That is, a KrF excimer laser (248 nm) and an ArF excimer laser (19
Exposure apparatuses using 3 nm) are being put to practical use. Exposure apparatuses using an F2 laser (157 nm) have also been developed with the aim of further miniaturizing the pattern shape.

When vacuum ultraviolet light having such a short wavelength is used as exposure light, light of such a wavelength range as oxygen molecules, water molecules, carbon dioxide molecules, etc. is placed in an optical path space through which the exposure light passes. If there is a substance having a strong absorption characteristic (hereinafter referred to as "light-absorbing substance") or an impurity such as particles, the exposure light is diminished and cannot reach the substrate with sufficient intensity, so that the exposure with high accuracy Processing cannot be performed. Therefore, in an exposure apparatus using vacuum ultraviolet light, it is necessary to reduce impurities such as light-absorbing substances existing in an optical path space through which exposure light passes.

Here, as a method of reducing the light absorbing substance (atmosphere) existing in the optical path space through which the exposure light passes, there is a method in which the inside of the optical path space is closed and then vacuum is maintained to maintain a reduced pressure state. After that, a method of filling with a substance having a property of less absorption property to exposure light (for example, an inert gas such as helium, argon, or nitrogen), or the like is used.

[0005]

However, the above-mentioned method is certainly effective as a method for removing the light-absorbing substance, but it is necessary to construct a closed chamber for keeping the optical path space in a closed state. For example, there is a problem that the cost of the entire apparatus increases due to the increase in size and complexity of the apparatus.

The present invention has been made in view of such circumstances, and in order to perform an accurate and stable exposure process, an exhaust method capable of removing a gas containing a light absorbing substance existing in an optical path space with a simple configuration. And an exhaust device, and an exposure method and an exposure apparatus.

[0007]

In order to solve the above-mentioned problems, the present invention employs the following structure corresponding to FIGS. 1 to 5 shown in the embodiment. The exhaust method according to claim 1 is an exhaust method for exhausting a predetermined gas existing in a space (SP, 6a) formed between two opposing objects (PL, P). Predetermined position (AR)
In contrast, the exhaust is performed while the pressure at the position of the outer edge of the space (SP) is set high.

According to the present invention, the pressure at the position of the outer edge of the space (SP) is changed to the predetermined position (AR) in the space (SP).
Space (SP)
The gas existing at the predetermined position (AR) in the space (SP) can be easily reduced while suppressing the gas entering from outside into the predetermined position (AR) in the space (SP) without making the airtight state. It is possible to stably exhaust with a simple configuration.

[0009] The exhaust device according to the fifth aspect is characterized in that the two exhaust devices are opposed to each other.
In an exhaust device (S) for exhausting a predetermined gas existing in a space (SP) formed between two objects (PL, P),
From a predetermined position (AR) in the space (SP), this space (S)
An exhaust mechanism (1) installed at a plurality of positions toward the outer edge position of P), and an exhaust mechanism (1) that performs exhaust while setting the pressure at the outer edge position higher than a predetermined position (AR). And a control device (CONT) for controlling (i.).

According to the present invention, the exhaust mechanism (1) is provided at a plurality of positions from the predetermined position (AR) in the space (SP) to the position of the outer edge of the space (SP), and the predetermined position (A) is provided.
By performing the evacuation operation while setting the pressure at the outer edge position higher than that of R), a predetermined position (A) in the space (SP) can be externally obtained without closing the space (SP).
The gas existing at a predetermined position (AR) in the space (SP) can be stably exhausted with a simple configuration while suppressing the gas entering into the space (R).

In the exposure method according to the ninth aspect, the mask (M) is irradiated with exposure light (EL) and an image of a pattern of the mask (M) is projected on the substrate (P) via the projection optical system (PL).
In the exposure method of transferring onto the upper side, a light absorbing substance having a characteristic of absorbing exposure light (EL), which is present in a space (SP) formed between the projection optical system (PL) and the substrate (P), is exhausted. At this time, a space (SP) is set with respect to a position corresponding to the projection area (AR) on the substrate (P) by the projection optical system (PL).
It is characterized in that exhaust is performed while the pressure at the outer edge position is set to be high, and the transfer process to the substrate (P) is performed after the concentration of the light absorbing substance reaches a predetermined value.

According to the present invention, when exhausting the light absorbing substance existing in the space (SP) formed between the projection optical system (PL) and the substrate (P), the substrate ( Since the air is exhausted while the pressure at the outer edge of the space (SP) is set to be higher than the position corresponding to the projection area (AR) on P), the projection optical system (PL) and the substrate (P ) Can be stably reduced with a simple configuration without having to make the space (SP) between the space (SP) and the space (SP) closed. Then, by performing the transfer process after the concentration of the light absorbing substance reaches a predetermined value, it is possible to perform the transfer process with high accuracy.

According to a tenth aspect of the present invention, in the exposure apparatus, the mask (M) is irradiated with exposure light (EL) and an image of a pattern of the mask (M) is projected through the projection optical system (PL).
In the exposure apparatus (EX) for transferring the light onto the top, the light absorbing material having the characteristic of absorbing the exposure light (EL), which is present in the space formed between the projection optical system (PL) and the substrate (P), is exhausted. An exhaust device (S) is provided.
Are exhaust mechanisms installed at a plurality of positions from the position corresponding to the projection area (AR) on the substrate (P) by the projection optical system (PL) in the space (SP) toward the outer edge of the space (SP). (1) A control device (CON) that controls the exhaust mechanism (1) to perform exhaust while setting the pressure at the outer edge position higher than the position corresponding to the projection area (AR).
T).

According to the present invention, the projection area (AR) on the substrate (P) by the projection optical system (PL) in the space (SP) formed between the projection optical system (PL) and the substrate (P). ), The exhaust mechanism (1) is provided at a plurality of positions from the position corresponding to the outer edge of the space (SP) to the projection area (AR).
By performing the exhaust operation while setting the pressure at the outer edge position higher than the position corresponding to the above, the projection area (AR) in the space (SP) can be externally input to the projection area (AR) in the space (SP) without closing the space (SP). The light-absorbing substance that enters can be stably suppressed with a simple configuration. By exhausting the light-absorbing substance existing in the space (SP) in this state, the light-absorbing substance existing in the exposure area (AR) can be stably reduced with a simple configuration. Therefore, an accurate transfer process can be performed.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view showing an embodiment of the present invention. FIG. 1 is a schematic configuration diagram of an exposure apparatus EX including an exhaust device S of the present invention. FIG. 2 is a schematic configuration diagram for explaining the exhaust device S, and FIG. 3 is a plan view of FIG.

As shown in FIG. 1, an exposure apparatus EX includes an illumination optical system IL for illuminating a light beam from a light source 101 onto a mask M.
An illumination system unit IU, a blind portion B arranged in the illumination optical system IL to adjust an area of an opening through which the exposure light EL passes and to define an illumination range of the mask M by the exposure light EL; Mask stage M supporting M
ST, a projection system unit PU including a projection optical system PL supported by the casing PK and projecting an image of the pattern of the mask M illuminated with the exposure light EL onto the photosensitive substrate P, and a substrate supporting the photosensitive substrate P Stage PST and projection optical system P
Exhaust device S for exhausting gas existing in a space formed between L and photosensitive substrate P supported on substrate stage PST
And

The light source 101 has, for example, an oscillation wavelength of 193n.
m ArF laser excimer laser, oscillation wavelength 157
nm laser (F2 laser), oscillation wavelength 14
The exposure light EL is composed of a 6 nm krypton dimer laser (Kr2 laser), an argon dimer laser (Ar2 laser) having an oscillation wavelength of 126 nm, and the like.
Is to be injected. Further, as the light source 101, an ArF laser excimer laser having an oscillation wavelength of 193 nm or the like can be used.

The exposure light EL emitted from the light source 101 is
Mirror 1 of illumination unit IU passing through window 102a
03a, the light is reflected by the mirror 103b and enters the illumination optical system IL. The illumination optical system IL includes a relay lens and an exposure light EL.
A plurality of lenses such as an optical integrator for equalizing the light, an input lens for exposing the exposure light EL to the optical integrator, a relay lens for condensing the exposure light EL emitted from the optical integrator on the mask M, and a condenser lens. Optical member).

The blind portion B is formed, for example, by a pair of blades which are bent into a plane L-shape and are combined in a plane orthogonal to the optical axis AX of the exposure light EL to form a rectangular opening. A drive mechanism D for displacing in a plane orthogonal to the axis AX. At this time, the size of the opening of the blind portion B changes with the displacement of the blade, and of the incident exposure light EL, only the passed exposure light EL is sent to the mask M side. The exposure light EL defined by the opening of the blind portion B illuminates a specific region of the mask M with substantially uniform illuminance.

Each of the optical members and the blind portion B of the illumination optical system IL is a casing I which is a closed space.
They are arranged in a predetermined positional relationship within K. In this case, the blind portion B is arranged on a plane conjugate with the pattern plane of the mask M.

The mask stage MST includes a mask holder for holding the mask M by vacuum suction, is disposed in a mask chamber MK which is a closed section, and is provided in a pattern area where a pattern on the mask M is formed. It has a corresponding opening. The mask stage MST can be finely moved in the X direction, the Y direction, and the θ direction (the rotation direction around the Z axis) by a driving mechanism (not shown).
The mask M can be positioned so that the center of the pattern area passes through the optical axis AX of the projection optical system PL.

In the ceiling of the mask room MK, the internal space of the illumination system unit IU and the mask room M in which the mask M is arranged
The window 102b is arranged so as to be separated from the K internal space. Then, the exposure light EL emitted from the illumination optical system IL is transmitted to the mirror 103 disposed in the casing IK.
c, passes through the window 102b, and passes through the mask stage M
The light enters the mask M on the ST.

The exposure light EL transmitted through the mask M passes through the window 1
02c via the projection optical system PL in the projection system unit PU
Incident on. The projection optical system PL forms an image of a pattern existing in the illumination range of the mask M defined by the opening of the blind portion B by the exposure light EL on the photosensitive substrate P, and a specific area (shot area) of the photosensitive substrate P To expose a pattern image. The projection optical system PL is composed of a plurality of optical members such as a lens and a reflecting mirror, and is arranged in a casing PK which is a closed space. Then, the exposure light EL transmitted through the mask M is transmitted through the projection optical system PL and is incident on the photosensitive substrate P.
Is formed on the surface of the photosensitive substrate P.

At this time, the mask chamber MK is joined to the casing IK of the illumination system unit IU and the casing PK of the projection system unit PU without any gap. The optical path space formed by the illumination system unit IU, the mask room MK, and the projection system unit PU is a closed space.

The photosensitive substrate P is held by a substrate holder PH for holding the photosensitive substrate P.
H is set on a substrate stage PST that can move in a three-dimensional direction (XYZ directions). The substrate holder PH holds the photosensitive substrate P by, for example, an electrostatic chuck using electrostatic force. Then, when the photosensitive substrate P is held by the substrate holder PH, the surface (exposure processing surface) of the photosensitive substrate P and the substrate stage PST are set to have the same height (same plane).

The position of the substrate stage PST in the XY plane is measured by the laser interferometer 105, while the position of the substrate stage PST in the Z direction is determined by a focus detection system (not shown) having a light projecting system and a light receiving system. (Shown). The measurement results of the laser interferometer and the focus detection system are output to the control unit CONT, and the substrate stage PST is moved via the drive mechanism PSTD based on an instruction from the control unit CONT.

The exposure apparatus EX according to the present embodiment
Means that the mask M and the photosensitive substrate P are stationary and the mask M
Is a step-and-repeat type exposure apparatus that exposes the pattern and sequentially moves the photosensitive substrate P stepwise.

Here, the illumination system unit IU, the mask room M
K, the optical path space of the exposure light EL, which is a closed space formed by the projection system unit PU, is an optically inert gas in which impurities (including light absorbing substances and particles) are reduced by a gas replacement device (not shown). Is satisfied by Specifically, nitrogen, helium, argon, neon,
It is a gas such as krypton or a mixed gas thereof, and has a characteristic of low absorption of light in a vacuum ultraviolet region (hereinafter, referred to as “inert gas”). That is, when light having a wavelength in the vacuum ultraviolet region is used as the exposure light EL, a gas having a strong absorption characteristic for light in such a wavelength band, such as oxygen, water vapor, or a hydrocarbon-based gas (hereinafter, referred to as the light). , "Light-absorbing substance"). For this reason, the gas in the optical path space is exhausted by the gas replacement device, and the inert gas is supplied to the optical path space, thereby reducing the concentration of the light absorbing substance in the optical path space.

The exhaust device S is provided with an opposing projection optical system PL.
A gas (light-absorbing substance, air) existing in a space SP formed between the (projection system unit PU) and the photosensitive substrate P supported on the substrate stage PST, and supports the photosensitive substrate P. It is arranged above substrate stage PST. This space SP is a space that is open to the outside atmosphere, and contains the atmosphere (light absorbing material).

As shown in FIGS. 1 and 2, the substrate stage P
The exhaust devices S disposed above the ST are installed at a plurality of positions from the position corresponding to the projection area AR on the photosensitive substrate P by the projection optical system PL in the space SP to the outside of the space SP. An exhaust mechanism 1 is provided.

As shown in FIGS. 2 and 3, the exhaust mechanism 1
A plurality of annular exhaust pipes 2 for exhausting gas existing in the space SP, and vacuum pumps (exhaust driving devices) 4 connected to the exhaust pipes 2 via connection pipes 3 respectively.
And A plurality of exhaust pipes 2 formed in an annular shape
Is a projection area AR on the photosensitive substrate P by the projection optical system PL.
(I.e., the optical axis AX of the projection optical system PL) are concentrically arranged with respect to the center of the projection optical system PL, and are supported by the exhaust pipe support 5 respectively. At this time, the separation distance between the plurality of exhaust pipes 2 supported by the exhaust pipe support 5 and the photosensitive substrate P is set to be equal.

Exhaust pipe support 5 supporting exhaust pipe 2
Is connected to the projection system unit PU via the tubular support 6. At this time, the shape of the space 6a inside the cylindrical support portion 6 is set so as not to obstruct the projection area AR of the projection optical system PL with respect to the photosensitive substrate P. The space 6 a inside the cylindrical support 6 is also connected to the vacuum pump 4 via the connection pipe 3.

The photosensitive substrate P of each exhaust pipe 2
, The surface of the exhaust pipe support 5 facing the photosensitive substrate P, and the lower end surface of the cylindrical support 6 are set to be at the same height (same plane).

When the vacuum pump 4 is driven, the gas (atmosphere, light-absorbing substance) in the space SP is exposed through a plurality of small holes (exhaust ports) provided at equal intervals in the circumferential direction of the exhaust pipe 2. The gas (atmosphere, light-absorbing substance) in the internal space 6a of the cylindrical support 6 is also exhausted to the outside of the exposure apparatus EX while being exhausted to the outside of the apparatus EX. At this time, the driving amount (displacement amount) of each vacuum pump 4 is controlled independently by the control device CONT. Accordingly, the amount of gas around the exhaust pipe 2 connected to the vacuum pump 4 and the amount of gas exhausted in the space 6a of the cylindrical support 6 are independently adjusted.

That is, the gas is provided at a plurality of positions radially outward of the space SP around the projection area AR of the projection optical system PL so as to be independently exhausted at each position.

After the gas (atmosphere, light-absorbing substance) existing in the space SP is exhausted by the exposure apparatus EX having the exhaust device S having the above-described configuration, the mask M
A method of transferring the image of the pattern formed on the photosensitive substrate P via the projection optical system PL will be described.

Here, the exhaust method of the present invention includes a step (step 1) of disposing a substrate stage PST supporting the photosensitive substrate P below the projection optical system PL and the exhaust apparatus S, and forming the exhaust apparatus S concentrically. Of the plurality of exhaust pipes 2 arranged, the outermost exhaust pipe 2a exhausts gas existing in the space SP, and the exhaust pipe 2b gradually disposed inside (the center side of the projection area AR). , 2c,... At the time when the light-absorbing substance in the space SP formed between the projection system unit PU and the photosensitive substrate P becomes equal to or lower than a predetermined concentration. A step of performing an exposure process on the photosensitive substrate P (Step 3).

<Step 1> A drive mechanism PS for supporting the photosensitive substrate P to be exposed on the substrate stage PST
The substrate stage PST is projected to the projection system unit PU by TD.
Move to a position away from. At this time, the driving mechanism PS
The TD moves the substrate stage PST outside the position where the exhaust device S is installed. Then, the photosensitive substrate P, the surface of which is coated with a photosensitive agent, is loaded into the substrate holder PH of the substrate stage PST by a substrate loader (not shown). When the photosensitive substrate P is loaded on the substrate holder PH, the substrate stage PST supporting the photosensitive substrate P is moved to a position directly below the projection optical system PL by the drive mechanism PSTD. At this time, the surface of the photosensitive substrate P and the substrate stage PST
Are on the same plane.

<Step 2> When the photosensitive substrate P is disposed immediately below the projection optical system PL, the control unit CONT is provided with a predetermined exhaust pipe 2 among a plurality of exhaust pipes 2 arranged concentrically of the exhaust apparatus S. Control is performed to exhaust the SP gas. In this case, the control unit CONT controls the gas in the space SP to be exhausted from the outermost exhaust pipe 2a. At this time, the exhaust operation by the other exhaust pipes 2 (2b, 2c) is not performed.

The control unit CONT uses an exhaust mechanism 1 having an exhaust pipe 2a disposed at the outermost side so that the pressure around the exhaust pipe 2a is substantially equal to the atmosphere (external atmosphere). adjust. Next, when the pressure around the outermost exhaust pipe 2a in the space SP is adjusted to be substantially equal to the atmosphere, the control device C
ONT is the second exhaust pipe 2 from the outermost to the innermost.
The exhaust mechanism 1 provided with the exhaust pipe 2b is driven, and the pressure adjusted by the exhaust pipe 2b located inside is adjusted to be lower than the pressure adjusted by the exhaust pipe 2a arranged outside. At this time, the exhaust operation by the exhaust pipes 2a and 2b is performed, but the exhaust operation by the exhaust pipe 2c is not performed.

When the pressure around the exhaust pipe 2b is adjusted to be lower than the pressure around the exhaust pipe 2a, the control unit CONT moves inward from the outermost side to the inner side. The exhaust mechanism 1 including the third exhaust pipe 2c is driven, and the pressure adjusted by the exhaust pipe 2c located inside is adjusted so as to be lower than the pressure adjusted by the exhaust pipe 2b. At this time, the exhaust pipes 2a to 2
Exhaust operation is performed by all exhaust pipes of c.

As described above, by using the exhaust mechanism 1 having the plurality of exhaust pipes 2 arranged concentrically, the space SP
The pressure at a plurality of positions from the outer position to the inner position is adjusted so as to gradually decrease.

Then, the pressure in the space corresponding to the projection area AR, that is, the space 6a, which is the space immediately below the projection optical system PL, is connected to the space 6a by using the vacuum pump 4 connected to the space 6a via the connection pipe 3. Adjust so that it is almost vacuum.

Thus, the exhaust pipes 2 arranged concentrically
Drive mechanism 1 having an exhaust pipe 2 provided outside
From the outside position toward the inside position (projection area AR), the pressure at a plurality of positions (positions where the exhaust pipes 2 are arranged) gradually decreases toward the inside. Set as follows. Then, the pressure at the outermost position in the space SP is adjusted to be substantially equal to the pressure (atmospheric pressure) of the external atmosphere, and the pressure in the space 6a corresponding to the projection area AR is adjusted to be substantially vacuum. I do.

At this time, by setting the outermost pressure of the space SP to approximately the atmospheric pressure, the projection area AR
The inflow of the atmosphere (gas) toward the side (the center side of the space SP) is suppressed. Then, by adjusting the pressure distribution so as to gradually decrease toward the projection area AR, the air in the projection area AR is exhausted while preventing the air from flowing into the projection area AR, and the light absorbing material is reduced. Can be.

Then, the evacuation operation is performed until the light-absorbing substance in the projection area AR becomes lower than a predetermined concentration. The predetermined density is a density sufficient to obtain a predetermined accuracy of an image of a pattern formed on the photosensitive substrate P when illuminated with the exposure light EL. A pattern having accuracy can be obtained. At this time, the light absorbing substance concentration can be measured by providing a sensor capable of measuring the light absorbing substance concentration in the space SP or the space 6a. On the other hand, the time required for the light-absorbing substance to be reduced to a predetermined concentration or less may be determined in advance by experiments, simulations, or the like, and the exhaust operation may be performed for this time, thereby eliminating the need for a sensor.

<Step 3> When the evacuation operation is performed until the light absorbing substance in the space SP (projection area AR) becomes equal to or less than a predetermined concentration,
The alignment of the photosensitive substrate P with respect to the projection optical system PL is performed. Note that this alignment process may be performed during the exhaust operation by the exhaust device S.

When the light-absorbing substance in the space SP is reduced to a predetermined concentration or less, the control unit CONT moves the mask M held on the mask stage MST with respect to the aligned photosensitive substrate P. Illumination optical system I
The substrate stage PST is irradiated with the exposure light EL from
The image of the pattern formed on the mask M is transferred to the photosensitive substrate P held by the projection optical system PL via the projection optical system PL. Note that the exhaust operation by the exhaust device S is performed during the exposure process.

When the exposure process for one photosensitive substrate P is completed, the control unit CONT drives the drive mechanism PSTD of the substrate stage PST to remove the exposed photosensitive substrate P from the projection optical system PL and the exhaust device S. Move from just below to the outside. Then, the photosensitive substrate P subjected to this exposure processing
And a new photosensitive substrate P is loaded on the substrate stage PST. Then, the substrate stage PST supporting the photosensitive substrate P is moved directly below the projection optical system PL (exhaust device S), and the photosensitive substrate P is exposed. When the photosensitive substrate P is loaded / unloaded to / from immediately below the projection optical system PL, the exhaust device S is constantly driven to reduce the light absorbing material in the space immediately below the projection optical system PL. Since the operation is continuously performed, the efficiency of the exhaust operation is improved.

As described above, the projection optical system PL and the photosensitive substrate P
By providing the exhaust device S for exhausting the light absorbing substance (atmosphere) existing in the space SP formed between
It is possible to prevent a decrease in the exposure amount due to the light absorbing material. Therefore, stable and accurate exposure processing can be performed.

In the present embodiment, unlike the configuration in which the projection optical system PL and the substrate stage PST are provided in a closed chamber and the entire chamber is evacuated or replaced with gas, the atmosphere (light absorbing material) existing in the open space SP It is not necessary to construct a closed chamber, provide a transfer device for transferring the photosensitive substrate P to the closed chamber, and provide a mechanism for opening and closing the closed chamber when transferring the sealed substrate to the closed chamber. Therefore, simplification of the apparatus and cost reduction can be realized.

When the gas (atmosphere) existing in the open space SP is exhausted, an exhaust mechanism 1 having an exhaust pipe 2 arranged concentrically with the space SP is used to exhaust gas from the outside to the inside of the space SP. The exhaust is performed while the pressure is gradually reduced toward, so that the inflow of the atmosphere from the external atmosphere into the projection area AR can be suppressed.

That is, first, when the atmosphere in the space corresponding to the projection area AR is exhausted, the pressure in the space corresponding to the projection area AR decreases, and gas (atmosphere) flows from the outside atmosphere, and the projection optical system In some cases, a desired effect of reducing the light-absorbing substance immediately below the PL cannot be obtained. However, by adjusting the pressure from the outside of the space SP and adjusting the pressure in a stepwise manner toward the inside, the air is present in the space of the projection area AR while suppressing the inflow of the atmosphere into the projection area AR. Light-absorbing substances can be stably reduced.

At this time, by setting the pressure at the outermost side (outer edge) of the space SP to be substantially equal to the pressure (atmospheric pressure) of the external atmosphere, the inflow of the air from the external atmosphere into the projection area AR is more reliably suppressed. be able to.

Then, the space 6a corresponding to the projection area AR
By setting a vacuum state, the light-absorbing substance in the projection area AR is sufficiently reduced, so that it is possible to prevent a decrease in the exposure amount due to the light-absorbing substance. Therefore, accurate exposure processing can be performed.

By setting the surface of the photosensitive substrate P and the upper surface of the substrate stage PST on the same plane, the workability when moving the photosensitive substrate P supported by the substrate stage PST directly below the projection optical system PL is set. Can be improved. In addition, since the exhaust pipe 2 and the exhaust pipe supporting portion 5 are set so as to be flush with each other, when the photosensitive substrate P supported by the substrate stage PST faces the projection optical system PL and the exhaust device S, the gas is exhausted. Flows smoothly. Therefore, the efficiency of the exhaust operation can be improved.

In the present embodiment, the exhaust pipe 2 is formed in an annular shape. However, the exhaust pipe 2 is set so that the pressure distribution in the space SP, such as an elliptical shape or a polygonal shape, becomes lower from the outside to the inside. Any shape is possible if possible. Further, the exhaust pipe 2 only needs to be arranged at a predetermined position from the outside to the inside of the space SP.
As shown in (1), a configuration in which a plurality of arc-shaped exhaust pipes are provided is also possible.

In this embodiment, of the exhaust pipes 2 arranged concentrically, the exhaust operation is first performed using the outermost exhaust pipe 2a, and the exhaust operation is sequentially performed using the inner exhaust pipe. However, if it is possible to set a pressure distribution such that the pressure outside the space SP is substantially equal to the atmospheric pressure, the pressure is gradually reduced toward the inside, and the pressure inside the space becomes a vacuum pressure,
It is also possible to simultaneously perform the exhaust operation by each exhaust pipe.

The substrate holder PH for holding the photosensitive substrate P is
For example, the substrate is held by an electrostatic chuck using electrostatic force. At this time, the holding force of the substrate holder PH on the photosensitive substrate P is smaller than the suction force on the photosensitive substrate P by the exhaust operation of the exhaust device S. It is only necessary to have a large force. Therefore, if the photosensitive substrate P can be stably held, various configurations such as using a vacuum chuck or increasing the number of vacuum chucks can be adopted.

In this embodiment, a photosensitive substrate P to be exposed is processed by a substrate loader on a substrate stage PST.
When loading the substrate stage PST, the substrate stage PST is moved to a position distant from the projection optical system PL and the exhaust device S, loading is performed at this distant position, and the substrate stage PST supporting the photosensitive substrate P is moved to the projection optical system PL. Although it is a configuration to convey to just below, by adopting such a configuration,
Exhaust pipe support 5 supporting exhaust pipe 2 and substrate stage PS
Even if the separation distance from the photosensitive substrate P on T is small, interference between the exhaust device S or the substrate stage PST and the substrate loader does not occur, so that the photosensitive substrate P can be stably arranged directly below the projection optical system PL. it can. While the substrate stage PST is kept directly below the projection optical system PL, the photosensitive substrate P to be exposed by the substrate loader is moved to the substrate stage PST.
Of course, it is also possible to adopt a configuration in which the data is loaded into the memory.

In the present embodiment, the exhaust pipe 2 is composed of 2a
~ 2c, but of course 4
It is possible to install any number of one or more exhaust pipes.

As the exposure apparatus EX of the present embodiment, the present invention can be applied to a scanning type exposure apparatus that exposes the pattern of the mask M by synchronously moving the mask M and the substrate P.

The application of the exposure apparatus EX is not limited to an exposure apparatus for manufacturing a semiconductor. For example, an exposure apparatus for a liquid crystal for exposing a liquid crystal display element pattern to a square glass plate, and a method for manufacturing a thin film magnetic head. It can be widely applied to an exposure apparatus for performing the above.

The magnification of the projection optical system PL may be not only a reduction system but also an equal magnification or an enlargement system.

As the projection optical system PL, when far-ultraviolet light such as excimer laser is used, a material which transmits far-ultraviolet light such as quartz or fluorite is used as a glass material. When F2 laser or X-ray is used, a catadioptric system or An optical system of a refraction system (a reticle of a reflection type is used), and when an electron beam is used, an electron optical system including an electron lens and a deflector may be used as the optical system. It goes without saying that the optical path through which the electron beam passes is in a vacuum state.

The substrate stage PST and the mask stage MS
When a linear motor is used for T, either an air levitation type using an air bearing or a magnetic levitation type using Lorentz force or reactance force may be used. Also,
The stage may be a type that moves along a guide or a guideless type that does not have a guide.

When a plane motor is used as the stage driving device, one of the magnet unit (permanent magnet) and the armature unit is connected to the stage, and the other of the magnet unit and the armature unit is connected to the moving surface side of the stage. (Base).

The reaction force generated by the movement of the substrate stage PST may be mechanically released to the floor (ground) by using a frame member as described in Japanese Patent Application Laid-Open No. 8-166475. The present invention is also applicable to an exposure apparatus having such a structure.

The reaction force generated by the movement of the mask stage MST is mechanically moved to the floor (ground) using a frame member as described in Japanese Patent Application Laid-Open No. 8-330224.
You may escape to The present invention is also applicable to an exposure apparatus having such a structure.

As described above, the exposure apparatus of the present embodiment
It is manufactured by assembling various subsystems including each component recited in the claims of the present application so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. Before and after this assembly, adjustments to achieve optical accuracy for various optical systems, adjustments to achieve mechanical accuracy for various mechanical systems, and various electric systems to ensure these various accuracy Are adjusted to achieve electrical accuracy. The process of assembling the various subsystems into the exposure apparatus includes mechanical connection, wiring connection of an electric circuit, and piping connection of a pneumatic circuit between the various subsystems. It goes without saying that there is an assembling process for each subsystem before the assembling process from these various subsystems to the exposure apparatus. When the process of assembling the various subsystems into the exposure apparatus is completed, comprehensive adjustment is performed, and various precisions of the entire exposure apparatus are secured. It is desirable that the exposure apparatus be manufactured in a clean room in which the temperature, cleanliness, and the like are controlled.

As shown in FIG. 5, for a semiconductor device, a step 201 for designing the function and performance of the device, a step 202 for manufacturing a mask (reticle) based on the design step, and a substrate (wafer) from a silicon material are manufactured. Step 203, a substrate processing step 204 of exposing a mask pattern to a substrate using the exposure apparatus of the above-described embodiment, and a device assembling step (dicing step,
(Including a bonding step and a package step) 205, an inspection step 206, and the like.

[0072]

The exhaust method and exhaust apparatus, exposure method and exposure apparatus of the present invention have the following effects. According to the exhaust method according to the first aspect and the exhaust device according to the fifth aspect, the space is sealed by setting the pressure at the position of the outer edge of the space higher than the pressure at the predetermined position in the space. Even if the state is not set, gas from the outside does not enter a predetermined position in the space. Then, by exhausting a predetermined gas existing in the space in this state,
The gas existing at a predetermined position can be stably exhausted with a simple configuration.

The exhaust method according to claim 2 and claim 6,
According to the exhaust device described in Item 7, the pressure at a plurality of positions from the position outside the space to the predetermined position is gradually increased by the exhaust pipe provided at these positions and the exhaust driving device connected to the exhaust pipe. , It is possible to suppress the intrusion of gas from the external atmosphere to a predetermined position in the space.

According to the third aspect of the present invention, by setting the pressure at the outer edge of the space to be equal to the pressure of the outer atmosphere of the space, the gas of the outer atmosphere enters the predetermined position in the space. Can be more reliably suppressed.

According to the exhaust method of the fourth aspect, by setting the pressure at the predetermined position in the space to the vacuum pressure, the predetermined gas existing at the predetermined position can be sufficiently reduced.

According to the eighth aspect of the present invention, a desired pressure distribution can be easily and accurately obtained inside the space by independently controlling each exhaust mechanism.

The exposure method according to claim 9 and the exposure method according to claim 10
According to the exposure apparatus described in the above, when exhausting the light absorbing substance existing in the space formed between the projection optical system and the substrate, the space of the space corresponding to the position corresponding to the projection area on the substrate by the projection optical system Since the exhaust is performed while the pressure at the outer edge is set to be high, the light-absorbing substance existing in the projection area in the space can be easily reduced without sealing the space between the projection optical system and the substrate. With the configuration, it can be stably reduced. The transfer process (exposure process) can be performed with high accuracy by performing the transfer process after the concentration of the light-absorbing substance reaches a predetermined value.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram for explaining an embodiment of an exposure apparatus provided with an exhaust device of the present invention.

FIG. 2 is a schematic configuration diagram of an exhaust device of the present invention.

FIG. 3 is a plan view of FIG. 2;

FIG. 4 is a plan view for explaining another embodiment of the present invention.

FIG. 5 is a flowchart illustrating an example of a manufacturing process of a semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exhaust mechanism 2 Exhaust pipe 3 Connection pipe 4 Vacuum pump (exhaust drive device) 5 Exhaust pipe support part (object) 6a Space AR Projection area (predetermined position) CONT control apparatus EL Exposure light EX Exposure apparatus M Mask P Photosensitive substrate ( Object) PL Projection optical system (Object) PST Substrate stage (Object) S Exhaust device SP Space

Claims (10)

[Claims] An exhaust method for exhausting a predetermined gas existing in a space formed between two opposing objects, wherein a pressure at an outer edge of the space is set higher than a predetermined position in the space. Exhaust method while performing the exhaust. 2. The exhaust method according to claim 1, wherein pressures at a plurality of positions from the position of the outer edge toward the predetermined position are gradually reduced. 3. The exhaust method according to claim 1, wherein a pressure at the outer edge is set equal to a pressure outside the space. 4. The exhaust method according to claim 1, wherein the pressure at the predetermined position is set to a vacuum pressure. 5. An exhaust device for exhausting a predetermined gas existing in a space formed between two opposing objects, wherein the exhaust device is installed at a plurality of positions from a predetermined position in the space to a position of an outer edge of the space. An exhaust device, comprising: a set exhaust mechanism; and a control device that controls the exhaust mechanism so as to perform exhaust while setting the pressure at the outer edge position higher than the predetermined position. 6. The exhaust device according to claim 5, wherein the exhaust mechanism includes an annular exhaust pipe arranged concentrically with respect to a predetermined position in the space, and a plurality of exhaust pipes connected to the exhaust pipe. An exhaust device comprising: an exhaust driving device. 7. The exhaust device according to claim 5, wherein the control device controls the exhaust mechanism such that pressures at a plurality of positions from the position of the outer edge toward the predetermined position gradually decrease. An exhaust device characterized by being controlled. 8. The exhaust device according to claim 5, wherein the control device is capable of controlling each of the exhaust mechanisms independently. 9. An exposure method for irradiating a mask with exposure light to transfer an image of a pattern of the mask onto a substrate via a projection optical system, wherein the image is formed in a space formed between the projection optical system and the substrate. When exhausting the light-absorbing substance having the characteristic of absorbing the exposure light, the pressure is set high at the position of the outer edge of the space with respect to the position corresponding to the projection area on the substrate by the projection optical system. An exposure method, wherein the transfer process is performed on the substrate after the gas is exhausted and the concentration of the light absorbing substance reaches a predetermined value. 10. An exposure apparatus for irradiating a mask with exposure light and transferring an image of a pattern of the mask onto a substrate via a projection optical system, wherein an image is formed in a space formed between the projection optical system and the substrate. An exhaust device for exhausting an existing light-absorbing substance having a characteristic of absorbing the exposure light, wherein the exhaust device is provided at an outer edge of the space from a position corresponding to a projection area on the substrate by the projection optical system in the space. An exhaust mechanism installed at a plurality of positions toward the position, and a control device that controls the exhaust mechanism to perform exhaust while setting the pressure at the position of the outer edge higher than the position corresponding to the projection area. An exposure apparatus comprising: