JP2004303808A - Aligner, exposure method, and film structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aligner and an exposure method which can hold the inside of an optical path space to the purity of at most several ppm level by sealing a gap between optical path space structural components which are divided for an adjustment mechanism while maintaining various alignment workability, even if it is an aligner using vacuum ultra-violet light, and to provide a film structure. <P>SOLUTION: The aligner 10 is provided with an exposure apparatus main body which transfers the pattern of a mask on a substrate W, and a segregation arrangement 71 which segregates a prescribed space S1 in the aligner main body from open air. The segregation arrangement 71 is provided with a first thin film member 72a, a second thin film member 72b which is arranged being isolated by a specified interval from the first thin film member 72a, and gas with which a space S3 between the first thin film member 72a and the second thin film member 72b is sealed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an exposure apparatus for manufacturing an electronic device such as a semiconductor device, a liquid crystal display device, an imaging device (such as a CCD), and a thin-film magnetic head.
[0002]
[Prior art]
When an electronic device such as a semiconductor element or a liquid crystal display element is manufactured by a photolithography process, a pattern image of a mask or a reticle (hereinafter, referred to as a reticle) having a pattern formed thereon is exposed to a photosensitive material (resist) via a projection optical system. There is used a projection exposure apparatus that projects onto each projection (shot) area on a substrate coated with. The circuit of the electronic device is transferred by exposing a circuit pattern on a substrate to be exposed by the projection exposure apparatus, and is formed by post-processing.
[0003]
In recent years, high-density integration of integrated circuits, that is, miniaturization of circuit patterns, has been promoted. Therefore, the wavelength of the exposure irradiation beam (exposure light) in the projection exposure apparatus tends to be shorter. That is, a short wavelength light source such as a KrF excimer laser (wavelength: 248 nm) is used instead of a mercury lamp that has been mainstream until now, and a practical use of an exposure apparatus using a shorter wavelength ArF excimer laser (193 nm) has been realized. Is also entering the final stage. Also, with the aim of high density integration, F ₂ Exposure equipment using a laser (157 nm) has been developed.
[0004]
Generally, a beam having a wavelength of about 190 nm or less belongs to the vacuum ultraviolet region, is called vacuum ultraviolet light, and has a property of not transmitting through air. This is because the energy of the beam is absorbed by substances (hereinafter, referred to as light absorbing substances) such as oxygen molecules, water molecules, and carbon dioxide molecules contained in the air. Further, in order to perform semiconductor manufacturing operations while securing sufficient productivity (throughput) using vacuum ultraviolet light, the concentration of the light absorbing substance must be suppressed to several ppm or less. As described above, the exposure apparatus using vacuum ultraviolet light is not easy to handle, because it is possible to transfer a finer light-shielding pattern, but it is necessary to remove light-absorbing substances.
[0005]
For this reason, in an exposure apparatus using vacuum ultraviolet light, a reticle stage system, a wafer stage system, and the like are housed in highly airtight chambers, respectively, and an illumination optical system is housed in a housing. Are housed in a lens barrel to reduce or eliminate light-absorbing substances in their internal spaces. Further, a single film-shaped bellows mechanism is used to mount between the housing and the lens barrel and the chamber containing the reticle stage system, and between the lens barrel and the chamber containing the wafer stage system and the like. (See Patent Document 1).
[0006]
[Patent Document 1]
WO 00/74120 pamphlet
[0007]
[Problems to be solved by the invention]
By the way, the kind of the light absorbing material to be suitably shielded differs depending on the kind of the film used in such a bellows mechanism. When the bellows mechanism made of this film is attached to the above-described exposure apparatus, the unshielded light-absorbing substance enters the exposure apparatus, the energy of the vacuum ultraviolet light is absorbed, and good exposure cannot be performed. In other words, there is a problem that semiconductor production with sufficient productivity cannot be performed.
[0008]
In view of the above, the present invention provides an exposure apparatus, an exposure method, and a film structure that allow a predetermined space in the exposure apparatus to be isolated from the outside air and keep the inside of the predetermined space at a desired atmosphere. The purpose is to do.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention employs the following configuration corresponding to FIGS. 1 to 9 showing the embodiment.
An exposure apparatus (10) of the present invention includes an exposure apparatus main body for transferring a pattern of a mask (R) onto a substrate (W) and an isolation mechanism (71) for isolating a predetermined space (S1) in the exposure apparatus main body from the outside air. In the exposure apparatus (10), the separating mechanism (71) includes a first thin film member (72a) and a second thin film member provided at a predetermined distance from the first thin film member (72a). (72b) and a gas sealed in a space (S3) between the first thin film member (72a) and the second thin film member (72b).
Therefore, in the exposure apparatus of the present invention, the invasion of the outside air into the space (S1) is suppressed by the isolation mechanism (71). Specifically, since the gas is sealed in the space (S3), even if the outside air permeates the second film (72b) of the isolation mechanism (71), the outside air enters the space (S1). Intrusion is suppressed. Further, even if the outside air in the space (S3) enters, since the isolation mechanism (71) further has the first film (72a), it can be prevented from entering the predetermined space (S1). That is, the predetermined space (S1) is kept airtight, and good exposure can be performed without the energy of the exposure light being absorbed by the outside air. Further, since the first thin film member (72a) and the second thin film member (72b) are formed of a flexible material, vibration propagation between the elements constituting the exposure apparatus (10) is suppressed. And stable optical characteristics can be obtained.
[0010]
Further, an exposure method of the present invention is characterized in that a mask pattern is transferred onto a substrate (W) using the above-described exposure apparatus (10).
Therefore, according to the exposure method of the present invention, the same effects as those of the above-described exposure apparatus (10) can be obtained, and the pattern accuracy can be improved.
[0011]
Further, the film structure (71) of the present invention is a film structure (71) for isolating a predetermined space (S1) in the exposure apparatus main body for transferring the pattern of the mask (R) onto the substrate (W) from the outside air. The film structure (71) includes a first thin film member (72a), a second thin film member (72b) provided at a predetermined distance from the first thin film member (72a), It is characterized by having a gas sealed in a space (S3) between the first thin film member (72a) and the second thin film member (72b).
Therefore, in the film structure of the present invention, the same effects as those of the above-described exposure apparatus (10) can be obtained.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
Hereinafter, an embodiment of an exposure apparatus according to the present invention will be described with reference to the drawings. In this embodiment, the present invention is applied to a step-and-scan projection exposure apparatus using vacuum ultraviolet light as an energy beam for exposure.
[0013]
FIG. 1 is a diagram showing a schematic configuration of an exposure apparatus 10 of the present embodiment, and is a configuration diagram in which a part of the exposure apparatus 10 is cut away.
As shown in FIG. 1, the configuration of the exposure apparatus 10 is roughly divided into an illumination optical system 21, a reticle operation unit (element) 22, a projection optical system (element) PL, and a wafer operation unit (element) 23. Can be. Among them, the illumination optical system 21, the reticle operation unit 22, and the projection optical system PL are provided inside a box-shaped illumination system chamber 25, a reticle chamber (element) 26, and a lens barrel (element) 27, respectively. The exposure apparatus 10 is housed in an environment chamber (not shown) in which the temperature of the gas inside is controlled within a predetermined target range as a whole. ) Is stored inside. In the exposure apparatus 10, a transparent gas (gas) is supplied to an optical path space through which the exposure light IL passes.
[0014]
Here, since the exposure light IL of the present example is vacuum ultraviolet light having a wavelength of 157 nm, the gas (substance that hardly absorbs energy) that the exposure light IL transmits is nitrogen gas (N ₂ ), Hydrogen (H ₂ ), Helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). Hereinafter, the nitrogen gas and the rare gas will be collectively referred to as “permeable gas”. On the other hand, as a gas absorbing the exposure light IL, oxygen (O ₂ ), Water (steam: H ₂ O), carbon monoxide (CO), carbon gas (carbon dioxide: CO ₂ ), Organic substances, and halides. Hereinafter, such a substance is referred to as a “light absorbing substance”.
[0015]
The illumination optical system 21 includes a mirror 30, a beam shaping optical system 31, a fly array lens 32, a mirror 34, a relay lens 35, a field stop mechanism 36 (reticle blind), a relay lens 37, and a mirror 38. And a condenser lens system 39. These devices are arranged on the optical path of the exposure light IL emitted from the exposure light source 20, and perform predetermined processing described later on the exposure light IL.
[0016]
The exposure light source 20 generates an F-pulse laser beam having a wavelength of 157 nm in a vacuum ultraviolet region. ₂ It is composed of a laser light source and generates the above-mentioned exposure light IL. The beam shaping optical system 31 shapes the cross-sectional shape of the illumination system and controls the light amount of the exposure light IL emitted from the exposure light source 20 and reflected upward by the mirror 30. The fly array lens 32 is configured as an optical integrator (homogenizer) and uniforms the intensity distribution of the exposure light IL. Further, an automatic tracking unit (not shown) for positioning an optical axis shift due to vibration or the like is provided at a stage preceding the beam shaping optical system 31.
[0017]
The field stop mechanism 36 is set so that its arrangement surface is substantially optically conjugate to the pattern surface of the reticle R to be exposed, and is formed in an elongated rectangular (slit) shape on the pattern surface. A fixed blind for defining the shape of the illuminated area, and a movable blind for closing the illuminated area at the start and end of the scanning exposure in order to prevent exposure to unnecessary portions. The field stop mechanism 36 is formed in a rectangular shape on the pattern surface of the reticle R through the relay lenses 35 and 37 disposed at the front and rear stages of the exposure light IL reflected substantially horizontally by the mirror 34. This is for illuminating the illuminated area with a uniform illuminance distribution. The condenser lens system 39 generates an even parallel light beam for the exposure light IL reflected downward by the mirror 38.
[0018]
When the reticle R is irradiated with the exposure light IL that has been subjected to a predetermined process by the illumination optical system 21, a pattern image in the illumination area of the reticle R is projected through the projection optical system PL at a projection magnification β (β is, for example, 1 / (4, 1/5, etc.), and is projected onto the wafer W coated with the photosensitive material (photoresist). Here, the wafer W is a disk-shaped substrate such as a semiconductor (such as silicon) or an SOI (Silicon On Insulator).
[0019]
Further, as in this example, the exposure light IL is F ₂ In the case of laser light, the optical glass material having a good transmittance is fluorite (CaF ₂ Crystal), quartz glass doped with fluorine or hydrogen, and magnesium fluoride (MgF ₂ ), It is difficult to obtain the desired imaging characteristics (such as chromatic aberration characteristics) by configuring the projection optical system PL with only the refractive optical member. Therefore, the projection optical system PL of this example employs a catadioptric system combining a refractive optical member as a refractive optical element and a reflecting mirror as a reflective optical element, and these refractive optical members and reflecting mirrors are mirrors. It is housed in a tube 27.
In the following description, the X axis is defined as a direction crossing the optical axis AX (see FIG. 2) of the projection optical system PL from the left side to the right side in the plane of FIG. 1 and vertically penetrating the plane of FIG. The direction from to the back side is the Y axis. In addition, the illumination area on the reticle R in this example is an elongated rectangle in the X-axis direction, and the scanning direction of the reticle R and the wafer W during exposure is in the Y-axis direction.
[0020]
The reticle operating section 22 includes a reticle R, a reticle chamber 26, a reticle stage 40, a reticle base (not shown), a reticle transport path 28, and a reticle load lock chamber (element) 29. The reticle R is one selected from a plurality of reticle groups RX arranged in the reticle load lock chamber 29, and is held on the reticle stage 40 after being transferred through the reticle transfer path 28. . The reticle stage 40 continuously moves the reticle R in the Y-axis direction in synchronization with a wafer stage (described later) on the reticle base, and reduces a synchronization error in the X-axis direction, the Y-axis direction, and the rotation direction around the Z-axis. The reticle R is finely driven so that the reticle R is driven. At this time, the reticle stage 40 is driven based on measured values of the position and rotation angle of the reticle stage 40 and control information from a main control system (not shown). (Not shown) to measure with high accuracy. Further, when the reticle is conveyed from the reticle load lock chamber 29 into the reticle chamber 26 via the reticle conveyance path 28, the operation is performed based on the control information of the main control system. Here, the main control system is composed of a computer that controls the overall operation of the apparatus.
[0021]
The wafer operation unit 23 includes a wafer holder 45 and a wafer stage 46. The wafer holder 45 is fixed on the wafer stage 46 in a state where the wafer W is suction-held on the mounting surface. The wafer stage 46 continuously moves the wafer W in the Y-axis direction in synchronization with the reticle stage 40 on a wafer base (not shown), and moves the wafer W stepwise in the X-axis direction and the Y-axis direction. is there. In addition, the wafer stage 46 uses the autofocus method to move the wafer W based on information about the position (focus position) in the direction of the optical axis AX (see FIG. 2) on the surface of the wafer W measured by an autofocus sensor (not shown). The surface is focused on the image plane of the projection optical system PL. The position of the wafer stage 46 in the X-axis direction and the Y-axis direction, the rotation angle around the X-axis (pitching amount), the rotation angle around the Y-axis (rolling amount), and the rotation angle around the Z-axis (yawing amount). Is measured with high precision by a laser interferometer (not shown), and based on the measured values and control information from the main control system, a wafer stage 46 is provided via a stage drive system (not shown). Is driven. The movable mirror 47a is mounted on the wafer stage 46 (wafer holder 45) and reflects a laser beam (length measurement beam) from a laser interferometer. The movable mirror 47a has an integrated L-shape. Various configurations can be applied, such as a mirror of a mold or a mirror in which the side surface of a wafer stage (wafer holder) is mirror-finished. This L-shaped mirror may be composed of separate prism mirrors. Further, the wafer operation unit 23 is configured by the wafer holder 45, the wafer stage 46, the wafer base, and the like, and a wafer loader or the like (not shown) as a transfer system is disposed beside the wafer operation unit 23.
[0022]
Further, the exposure apparatus 10 of the present embodiment is configured to absorb energy in the space on the optical path of the exposure light IL, that is, in each of the illumination system chamber 25, the reticle chamber 26, and the lens barrel 27 with respect to the beam in the vacuum ultraviolet region. A gas supply / exhaust system (gas supply) that supplies and fills a small amount of the above-mentioned permeable gas and makes the pressure equal to or higher than the atmospheric pressure (for example, within a range of 0.001 to 10% of the atmospheric pressure). Mechanism 50). The gas supply / exhaust system 50 includes exhaust pumps 51A, 51B and 51C for exhaust, a cylinder 53 in which a permeable gas is compressed or liquefied and stored in a high purity state, and valves 52A, 52B and 52C which are controlled to open and close. And so on. Note that the numbers and installation locations are not limited to those shown in the drawings. Nitrogen gas acts as a light absorbing substance for light having a wavelength of about 150 nm or less, and helium gas can be used as a transparent gas up to a wavelength of about 100 nm. Helium gas has a thermal conductivity about six times that of nitrogen gas, and the amount of change in the refractive index with respect to a change in atmospheric pressure is about の of that of nitrogen gas. Excellent in stability and cooling. Since helium gas is expensive, the wavelength of the exposure light is F ₂ If the thickness is 150 nm or more as in a laser, nitrogen gas may be used as the permeable gas in order to reduce operating costs.
[0023]
FIG. 2 is an enlarged cross-sectional view of a portion between the lower end of the projection optical system PL of FIG. 1 and the wafer (substrate) W, that is, the working distance portion WD.
A purge guide plate 70 surrounding the optical axis AX of the projection optical system PL and having an opening 70a through which exposure light IL emitted from the projection optical system PL passes is disposed in the working distance section WD. . The purge guide plate 70 has an exhaust device 64 and an air supply device 67, and is provided on a column (not shown). An isolation mechanism (film structure) 71 is provided between the purge guide plate 70 and the lens barrel 27 so as to surround the exposure light IL.
[0024]
The purge guide plate 70 is formed of stainless steel or ceramics. Here, a space provided between the purge guide plate 70 and the lens barrel 27, that is, a space from the projection optical system PL to the opening 70a is a space S1, and a space between the purge guide plate 70 and the wafer W is a space S2. And
[0025]
The exhaust device 64 includes an exhaust pump 60 for exhaust, an exhaust pipe 61, and an exhaust port 66. The gas in the space S <b> 1 is exhausted by the exhaust pump 60 through the exhaust pipe 61 and the exhaust port 66. It is supposed to. The air supply device 67 includes a valve 63, a gas supply pipe 62, and a gas supply port 65, and is configured to supply a light-transmissive gas to the space S1 from a cylinder 53 (described later). Further, the supply amount of the light transmitting gas supplied from the gas supply port 65 is set to be larger than the exhaust amount of the light transmitting gas exhausted from the exhaust port 66.
[0026]
The isolation mechanism 71 includes a first film (first thin film member) 72a located inside (space S1 side) of the isolation mechanism 71 and a second film (second thin film member) located outside (atmosphere side) thereof. 72b, and a holding member 73 for holding the first and second films 72a and 72b.
The holding member 73 includes a first holding member (first holding portion) 73 a having an attachment surface attached to the lens barrel 27 and a second holding member (second holding member) having an attachment surface attached to the purge guide plate 70. Part) 73b. The first holding member 73a and the second holding member 73b are each formed in a frame shape.
The first holding member 73a has a mounting portion to which the first film 72a and the second film 72b are mounted on a surface opposite to the mounting surface. Then, one end of the first film 72a and one end of the second film 72b are attached with the first film 72a having a cylindrical shape and the second film 72b having a cylindrical shape being separated from each other by a predetermined distance. Mounted on the part.
Further, the second holding member 73b has, on a surface opposite to the mounting surface, a mounting portion to which the first film 72a and the second film 73b are mounted. The other end of the first film 72a and the other end of the second film 72b are separated from each other by a predetermined distance between the first film 72a and the second film 72b. It is attached to the attachment part.
As a material of the first holding member 73a and the second holding member 73b, aluminum, stainless steel, or the like is adopted, and a material having excellent workability is preferable.
As described above, the space S3 is formed by holding the one end and the other end of the first film 72a and the second film 72b with the first holding member 73a and the second holding member 73b, respectively.
In the present embodiment, a part of the first holding member 73a on the side where the mounting surface is formed may be embedded in a recess formed in a part of the lens barrel 27, A flange to which the first holding member 73a is attached may be provided in a part of the lens barrel 27, and the holding member 73 may be fastened to this flange.
[0027]
Further, the first holding member 73a has a gas supply port (gas supply port) 76 for supplying a permeable gas to the space S3, and the second holding member 73b has a gas (gas supply port) in the space S3. It has a gas exhaust port (gas exhaust port) 77 for exhausting a mixed gas containing several percent of a light absorbing substance in a permeable gas supplied from the port. One or a plurality of gas supply ports 76 are provided for the first holding member 73a at equal intervals. Further, one or more gas exhaust ports 77 are provided at equal intervals with respect to the second holding member 73b. In the present embodiment, the gas supply port 76 and the gas exhaust port 77 are provided so as to face each other.
Further, both the gas supply port 76 and the gas exhaust port 77 may be formed only in the first holding member 73a (or the second holding member 73b). In this case, it is desirable that a plurality of gas supply ports 76 and gas exhaust ports 77 are provided alternately with respect to the first holding member 73a. Further, at least one of the gas supply port 76 and the gas exhaust port 77 may be provided in the second film 72b.
[0028]
A gas supply pipe 75 is connected to the gas supply port 76, a valve 63 is provided at an arbitrary position of the gas supply pipe, and a permeable gas supplied from the cylinder 53 is supplied to the space S3. I have. Further, the gas exhaust port 77 is provided so as to penetrate a part of the purge guide plate 70, and the permeable gas in the space S3 is exhausted to the outside of the exposure apparatus 10. Here, the transparent gas supplied to the space S3 is preferably the same type as the transparent gas supplied to the space on the optical path of the exposure light IL. In this case, the refractive index does not change due to the mixing of different kinds of gases, and it is possible to prevent fluctuations and the like with respect to the interferometer, so that accurate measurement can be performed. When the space in the lens barrel 27 and the space S1 are spatially separated, the permeable gas supplied to the space in the lens barrel 27 and the permeable gas supplied to the space S1 are different from each other. However, the types may be different from each other. For example, He gas may be supplied to the space inside the lens barrel 27, and N2 gas may be supplied to the space S1.
In addition, it is desirable that at least one of the gas supply port 76 and the gas exhaust port 77 be provided with a particle filter for removing dust and a chemical filter for removing organic substances (light absorbing substances).
Further, in the present embodiment, the permeable gas is exhausted from the gas exhaust port 77, but the permeable gas supplied from the gas supply port 76 is provided in the space S3 without providing the gas exhaust port 77. In a sealed state. Further, the permeable gas exhausted from the gas exhaust port 77 to the outside of the exposure apparatus 10 may be collected by the exhaust pump 60.
[0029]
One end and the other end of the first film 72a and the second film 72b are connected to the O-ring and the clamp member (for example, the protrusion) of the first holding member 73a and the protrusion of the second holding member 73b. , A hose clamp), or an adhesive that suppresses the generation of a light-absorbing substance. Here, the fastening member, the adhesive and the like are preferably arranged outside the space S1, and more preferably arranged outside the exposure apparatus 10. In this case, it is possible to prevent gas released from the O-ring or the adhesive from entering the space S1.
[0030]
As described above, since the first and second films 72a and 72b are fastened to the lens barrel 27 and the purge guide plate 70 via the holding member 73, it is possible to prevent the lens barrel 27 from being distorted. .
Here, since the first and second films 72a and 72b are made of a flexible material, the distance between the lens barrel 27 and the purge guide plate 70 can be flexibly and easily displaced.
Note that the first and second films 72a and 72b may be bent in a bellows shape.
[0031]
The first film 72a has a shielding film (second thin film) formed of a thin film material (second material) that shields a light absorbing substance that enters the optical path space of the exposure light IL. As such a thin film material, for example, EVAL (manufactured by Kuraray Co., Ltd.), Kapton (manufactured by Dupont), Mylar (manufactured by Dupont), and the like are preferable. In this example, EVAL is employed. Further, the first film 72a is not limited to a single-layer structure including only the shielding film, and may have a laminated structure including a shielding film and a plurality of films. In the case of a laminated structure, a stretchable film (first material) formed of a stretchable thin film material (first material) via an adhesive is provided on the outer surface of a thin film material (second material) for shielding the light absorbing substance. A thin film), and further, a metal thin film (metal film) is coated on the inner surface of the thin film material (first material). Here, polyethylene, polyurethane, or the like is used as the material of the elastic film. Further, as a material of the metal thin film, an inorganic substance such as Al (aluminum) is adopted, and the metal thin film is preferably formed by a vapor deposition method using a vacuum device. According to such a laminated structure, the first film 72a which not only blocks the invasion of the light absorbing substance but also can be flexibly expanded and contracted, and is excellent in strength and UV resistance.
[0032]
In order to close the first film 72a thus configured in a cylindrical shape, after bending the ends of the film so that the stretchable films face each other, the stretchable films having excellent weldability are welded to each other, The first film 72a can be formed in a cylindrical shape. The inner surface of the first film 72a thus formed in a cylindrical shape is covered with a thin metal film. The second film 72b is also formed of a shielding film similar to the first film 72a, and is closed in a cylindrical shape.
[0033]
It is preferable that the first film 72a and the second film 72b be formed using a shielding film that shields all of the light absorbing substance.
However, the first film 72a and the second film 72b of the present embodiment may be configured as follows without using a shielding film having a property of shielding all the light absorbing substances.
For example, as the shielding film forming the first film 72a, among the light-absorbing substances, a material that hardly transmits oxygen but has a property of transmitting water vapor is used, and as the shielding film forming the second film 72b, It is difficult to transmit water vapor, but a material having a property of transmitting oxygen may be used. As described above, even if the first film 72a and the second film 72b are formed of the shielding films having different characteristics, it is possible to suppress the penetration of the light absorbing substance into the space S1 by supplementing the characteristics lacking in the respective films. Becomes possible.
Further, as the first film 72a and the second film 72b, among the light-absorbing substances, those having a property of hardly transmitting oxygen but having a property of transmitting water vapor may be used. As described above, when the shielding films having the same characteristics are used, the water vapor permeates the second film 72b and enters the space S3. However, the water vapor that has entered the space S2 can be discharged from the gas exhaust port 77 together with the permeable gas supplied to the space S3, so that the water vapor hardly permeates the space 1 through the first film 72a. .
[0034]
In the exposure apparatus 10 configured as described above, the air supply device 67 provided on the purge guide plate 70 supplies the permeable gas into the space S1, and the exhaust device 64 removes the light-absorbing substance existing in the space S1. Since the air is exhausted together with the permeable gas, the space S1 is filled with the permeable gas. Further, since the supply amount of the permeable gas of the air supply device 67 is set to be larger than the exhaust amount of the exhaust device 64, when a predetermined time elapses after the supply of the permeable gas into the space S1, the space S1 Is filled with a permeable gas, and the permeable gas is also supplied to the space S2 through the opening 70a. The supply of the permeable gas from the inside of the space S1 to the inside of the space S2 does not start after the space S1 is completely filled with the permeable gas. Supplies the permeable gas into the space S2.
[0035]
Further, in the isolation mechanism 71, the permeable gas is supplied from the cylinder 53 into the space S 3 via the gas supply pipe 75 and the gas supply port 76, and the permeable gas is exhausted from the gas exhaust port 77. Therefore, even if the gas newly entering the space S1 passes through the second film 72b of the isolation mechanism 71, the gas is exhausted from the gas exhaust port 77 together with the permeable gas flowing in the space S3. In addition, as the shielding film forming the first film 72a, among the light-absorbing substances, one having a property of hardly transmitting oxygen but having a property of transmitting water vapor is used, and as the shielding film forming the second film 72b, In the case of using a material that is difficult to transmit water vapor but has a property of transmitting oxygen, even if the oxygen concentration in the space S3 increases, the gas is exhausted from the gas exhaust port 77 together with the permeable gas flowing in the space S3. Is done. Further, since the shielding film forming the first film 72a has a property of hardly transmitting oxygen, it is possible to prevent oxygen from entering the space S3.
In addition, as another example of the configuration of the first film 72a and the second film 72b, the first film 72a has a laminated structure of the above-described shielding film such as Eval, a stretch film, and a metal thin film, and the second film 72b has You may comprise with an elastic film. In this case, since the second film 72b does not have the property of shielding the light absorbing substance, all of the light absorbing substance penetrates the second film 72b and enters the space S3. However, the light absorbing substance that has passed through the second film 72b is exhausted from the gas exhaust port 77 together with the permeable gas supplied to the space S3, and is shielded by the shielding film that constitutes a part of the first film 72b. , The space S1 is suppressed.
[0036]
Further, the exposure light IL irradiates the reticle R, and the pattern image of the reticle R is incident on the projection optical system PL and is transferred to the wafer W after being reduced by a predetermined projection magnification. Here, since the light absorbing material is excluded in the working distance portion WD, the exposure can be performed well without absorbing the energy of the exposure light IL due to the light absorbing material.
[0037]
In this example, the amount of supply of the permeable gas from the gas supply port 65 and the amount of the gas from the exhaust The displacement may be changed. The same applies when the wafer W is replaced. Further, a concentration meter for measuring the concentration of the light-absorbing substance in the working distance unit WD may be provided, and the concentration control may be performed by adjusting the supply amount and the exhaust amount of the permeable gas based on the measurement result. Further, in order to make the flow of the permeable gas into a desired state, a rectifying plate, a guide, or the like may be appropriately provided.
[0038]
In addition, the amount and type of degassing containing a light-absorbing substance from the photosensitive material (photoresist) applied on the wafer W differ depending on the type and temperature of the photosensitive material. In this case, the amount and type of outgassing from the photosensitive material may be investigated in advance, and the supply amount of the permeable gas may be adjusted depending on the photosensitive material. This makes it possible to reliably eliminate light-absorbing substances from the working distance unit WD, while minimizing the consumption of generally expensive permeable gas.
[0039]
Further, in order to eliminate the light absorbing substance from the optical path of the exposure light IL, it is preferable to perform a treatment for reducing the amount of outgas from the surface of the structural material in advance. For example, (1) the surface area of the structural material is reduced, (2) the surface of the structural material is polished by a method such as mechanical polishing, electrolytic polishing, buff polishing, chemical polishing, or GBB (Glass Beads Blasting) to obtain a surface roughness of the structural material. (3) cleaning the surface of the structural material by a technique such as ultrasonic cleaning, spraying a fluid such as clean dry air, or vacuum degassing (baking); and (4) removing hydrocarbons and halides. There is a method in which a wire coating material, a sealing member (such as an O-ring), an adhesive and the like are not installed in the optical path space as much as possible.
[0040]
In addition, a casing (a cylindrical body or the like) constituting a cover of the wafer operation unit 23 from the illumination system chamber 25 and a pipe for supplying a permeable gas are made of a material with little impurity gas (degassing), for example, stainless steel. , Titanium alloy, ceramics, tetrafluoroethylene, tetrafluoroethylene-terfluoro (alkyl vinyl ether), or various polymers such as tetrafluoroethylene-hexafluoropropene copolymer.
[0041]
Similarly, it is desirable that a cable for supplying electric power to a drive mechanism (reticle blind, stage, etc.) in each housing is similarly coated with the above-described material having a small amount of impurity gas (degassing).
[0042]
In the first embodiment, the configuration in which the isolation mechanism 71 as the film structure is disposed between the lens barrel 71 and the purge guide plate 70 has been described. However, the present invention is not limited to the configuration in which the isolation mechanism 71 is disposed between the lens barrel 71 and the purge guide plate 70. The isolation mechanism 71 can be appropriately used in a place where a predetermined space needs to be isolated from the outside air in the exposure apparatus main body. It is.
Hereinafter, other embodiments using the isolation mechanism 71 in the exposure apparatus main body, that is, second to fifth embodiments will be described.
Here, the same elements as those of the first embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted. Only different parts from the first embodiment will be described.
Since the structure of the film structure is the same as the structure described in the first embodiment, the description of the film structure is omitted here.
[0043]
(2nd Embodiment)
FIG. 3 is an enlarged cross-sectional view of the projection optical system PL showing the second embodiment.
In this example, the projection optical system PL includes a plurality of divided lens barrels 100a to 100k stacked in the optical axis AX direction, and is supported by a lens barrel base (not shown) via a flange F. The lens elements 101b, 101d, 101e, 101f, and 101g supported by the divided barrels 100b, 100d, 100e, 100f, and 100g among the plurality of divided barrels 100a to 100k are in the optical axis AX direction (Z direction). ) And a movable lens element that can be tilted about the X direction or the Y direction.
[0044]
The configuration of the split lens barrels 100b, 100d, 100e, 100f, and 100g holding the lens elements 101b, 101d, 101e, 101f, and 101g will be described with reference to the configuration of the split lens barrel 100b. Note that the configuration of the other divided lens barrels 100d, 100e, 100f, and 100g is almost the same as the configuration of the divided lens barrel 100b, and thus the description is omitted here.
The split barrel 100b includes an outer ring 102b connected to the split barrels 100a and 100c located above and below (in the Z direction) the split barrel 100b, and a lens holding unit 103b that holds the lens element 101b. The lens holding portion 103b is movable with respect to the outer ring 102b in the optical axis AX direction (Z direction) and tilted around an axis parallel to the X axis or an axis parallel to the Y axis. 102b is connected via a drive mechanism (piezo element or the like).
[0045]
The lens elements 101a, 101c, 101h, 101i, 101j, and 101k supported by the divided barrels 100a, 100c, 100h, 100i, 100j, and 100k among the divided barrels 100a to 100k illustrated in FIG. It is a fixed lens. For example, the split lens barrel 100c is connected to the split lens barrels 100b and 100d located above and below (in the Z direction) the split lens barrel 100c, and a lens attached to the outer ring 102c and holding the lens element 101c. And a holding unit 103c. Note that the lens elements 101a to 101k may be constituted by a single lens element, or may be constituted by a lens group obtained by combining a plurality of lens elements.
[0046]
Further, the projection optical system PL has an isolation mechanism 71, and the isolation mechanism 71 is arranged at a portion where the divided barrels 100a to 100k are stacked so as to surround the optical axis AX. The split barrels 100a to 100k each have a fastening portion T to which a mounting surface of the first holding member 73a and a mounting surface of the second holding member 73b of the isolation mechanism 71 are attached. The occurrence of distortion of the outer rings 102a to 102k and the flange F due to the fastening is prevented.
[0047]
In the split lens barrels 100a to 100k configured as described above, since the separation mechanism 71 is provided, it is possible to suppress the invasion of the light absorbing substance from the gap between the split lens barrels 100a to 100k. The same effects as those of the first embodiment can be obtained.
[0048]
Next, a modified example of the second embodiment will be described.
FIG. 4 is an enlarged cross-sectional view showing the projection optical system PL including the split lens barrel.
In this modification, only the differences between FIG. 3 and FIG. 4 will be described, and the other configuration is the same as that of the second embodiment. The isolation mechanism 71 shown in FIG. 3 has a configuration in which the divided lens barrels 100a to 100k and the flange F are arranged at a portion where they are stacked, but the isolation mechanism 71 of the present modified example has the entire outer rings 102a to 102k. Are disposed so as to cover. Here, a fastening portion T to which the mounting surface of the first holding member 73a and the mounting surface of the second holding member 73b of the separating mechanism 71 are mounted is formed in the divided barrels 100a and 100k and the flange F. As described above, the occurrence of distortion of the outer rings 102a and 102k is prevented.
In the projection optical system PL configured as described above, the same effect as described above is achieved, and the number of the fastening portions T is reduced by the split lens barrel 71 covering the entire outer rings 102a to 102k. It is possible to suppress the intrusion of the light absorbing substance from the joint surface between the part T and the isolation mechanism 71.
[0049]
Next, another modified example of the second embodiment will be described.
FIG. 5 is an enlarged cross-sectional view showing the divided lens barrels 100b and 100c in the projection optical system PL including the divided lens barrels. The divided lens barrels 100b and 100c shown in FIG. 5 are representatively shown as a part of the projection optical system PL, and the other divided lens barrels have the same configuration, and thus the description will be omitted.
In this modified example, only the differences between FIG. 3 and FIG. 5 will be described, and the other configuration is the same as that of the second embodiment. Although the split lens barrel 100b shown in FIG. 3 is stacked on the split lens barrel 100c, the split lens barrels 100b and 100c shown in FIG. 5 are arranged without contact and are separated from each other. An isolation mechanism 71 is provided so as to surround a space between the lens barrels 100b and 100c.
In the projection optical system PL configured as described above, since the first film 72a and the second film 72b of the isolation mechanism 71 have elasticity, the position of one of the split lens barrels 100b and 100c is changed. In this case, the other position does not shift, and no vibration is transmitted. Therefore, in this modification, the same effects as described above can be obtained, and when optical adjustment of the projection optical system PL is performed, only the necessary divided lens barrel can be adjusted, and the optical adjustment is performed with high precision. be able to.
[0050]
(Third embodiment)
FIG. 6 is an enlarged cross-sectional view between the reticle operating unit 22 and the projection optical system PL showing the third embodiment.
In this example, the reticle chamber 26 has an opening 26a through which the exposure light IL passes, and an isolation mechanism 71 is provided between the opening 26a and the lens barrel 27 so as to surround the exposure light IL. ing.
In such a configuration, the same effect as described above is obtained, and vibration generated in the reticle operation unit 22, for example, vibration of the reticle chamber 26 due to driving of the reticle stage 40 or conveyance of the reticle R is not transmitted to the lens barrel 27. Therefore, by passing through the lens barrel 27, the pattern image of the reticle R reduced by the predetermined projection magnification is transferred onto the wafer W without blurring, and good exposure can be performed.
In this example, a window material may be fitted into the opening 26a so that the exposure light IL passes through the window material.
[0051]
Next, a modified example of the third embodiment will be described.
FIG. 7 is an enlarged cross-sectional view between the reticle operation unit 22 and the projection optical system PL.
In this modification, the reticle chamber 26 and the lens barrel 27 have a fastening portion T, and the isolation mechanism 71 is provided in the fastening portion T. An O-ring OR having low degassing property is arranged between the isolation mechanism 71 and the fastening part T, and a screw SC arranged outside the O-ring OR fastens the isolation mechanism 71 and the fastening part T. ing. Here, the isolation mechanism 71 and the fastening portion T can be hermetically sealed by tightening with a hose clamp, but in this case, the direction perpendicular to the optical axis AX (X direction, Y direction). , A non-removable distortion occurs in the reticle chamber 26 and the lens barrel 27, the optical axis AX is shifted, and desired exposure characteristics cannot be obtained. In this modification, the screw SC fastens the isolation mechanism 71 to the fastening portion T, so that the fastening force acts in the axial direction (Z direction) of the optical axis AX. The fastening using the screw SC is not limited, and another fastening member such as a claw clamp may be used as long as the fastening force acts in the Z direction. The screw hole in which the screw SC is arranged is preferably an unpenetrated screw hole. In this case, a high degree of sealing is obtained.
In such a configuration, the same effect as described above is achieved, and since the O-ring OR is arranged, it is possible to suppress the intrusion of the light absorbing substance from the joint surface between the isolation mechanism 71 and the fastening portion T. . Further, since the tightening force of the screw SC acts in the Z direction, the distortion of the lens barrel 27 due to the tightening force is suppressed to a minimum, so that the desired exposure can be performed without impairing the positional accuracy of the pattern image of the reticle R. It can be carried out.
[0052]
(Fourth embodiment)
FIG. 8 is an enlarged side view of the reticle operation unit 22 showing the fourth embodiment.
In this example, the reticle transport path 28 is covered by an isolation mechanism 71, and the isolation mechanism 71 is disposed between the reticle chamber 26 and the reticle load lock chamber 29.
In the reticle operating section 22 configured as described above, the same effect as described above is obtained, and the vibration accompanying the transport of the reticle R is not transmitted to the reticle chamber 26. Accordingly, there is no error of the laser interferometer with respect to the movable mirror (not shown), and the fine driving of the reticle R and the positional accuracy thereof are kept high, so that good exposure can be performed.
[0053]
(Fifth embodiment)
FIG. 9 is an enlarged cross-sectional view of the wafer operation unit 23 according to the fifth embodiment.
In this example, the wafer operation unit 23 maintains the wafer W in a sealed state, the stage base 203 having the wafer stage 46 in the chamber 201, and a vibration removing mechanism that eliminates vibration transmitted to the stage base 202. The configuration includes a force canceller 203. The chamber 201 is provided with the above-described cylinder 53, gas supply pipe 62, valve 63, exhaust pump 60, and exhaust pipe 61, and the light-transmitting gas is supplied while the inside of the chamber 201 is kept airtight. It has become. An isolation mechanism 71 is provided in the opening 201a of the chamber 201, and suppresses intrusion of a light absorbing substance from between the projection optical system PL and the wafer operation unit 23. An isolation mechanism 71 is provided at a portion Q where the reaction force canceller 203 is inserted into the chamber 201. One holding member 73d of the isolation mechanism 71 is outside the chamber 201, and the other holding member 73e is a reaction force canceller. 203.
In the wafer operation unit 23 thus configured, since the isolation mechanism 71 is provided at the portion Q, the chamber 201 is air-tightly filled with the light transmitting gas while eliminating the vibration by the reaction force canceller 203. The same effect as described above is achieved.
[0054]
As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings. However, it is needless to say that the present invention is not limited to the embodiments. It is obvious that those skilled in the art can conceive various changes or modifications within the scope of the technical idea described in the claims, and it is obvious that the technical scope of the present invention can also be conceived. It is understood that it belongs to.
[0055]
In the present invention, the position where the isolation mechanism 71 is installed is not limited to the position shown in the above embodiment, and among the plurality of components included in the exposure apparatus 10, the mutual transmission of the components whose vibration transmission is suppressed is reduced. It may be arranged between them.
[0056]
It is apparent that the present invention can be applied to not only a scanning exposure type projection exposure apparatus but also a batch exposure type (stepper type) projection exposure apparatus. The projection optical system provided therein may be not only a catadioptric system but also a dioptric system or a reflective system. Further, the magnification of the projection optical system may be not only the reduction magnification but also an equal magnification or an enlargement.
[0057]
Further, the present invention relates to a case where an ArF excimer laser beam (wavelength 193 nm) is used as an energy beam, ₂ Laser light (wavelength 146 nm), Ar ₂ The present invention can also be applied to vacuum ultraviolet light having a wavelength of about 200 nm to 100 nm, such as laser light (having a wavelength of 126 nm), a harmonic such as a YAG laser, or a harmonic of a semiconductor laser.
Further, the present invention can be used not only in an exposure apparatus using vacuum ultraviolet light, but also in an exposure apparatus using a charged particle beam such as an X-ray or an electron beam. As a projection optical system, when a far ultraviolet ray such as an excimer laser is used, a material that transmits the far ultraviolet ray such as quartz or fluorite is used as a glass material, and when a X-ray is used, a reflection optical system is used. In the case of using an electron beam, an electron optical system including an electron lens and a deflector may be used as an optical system. It goes without saying that the optical path through which the electron beam passes is set in a vacuum state.
[0058]
Excimer laser or F ₂ Instead of a laser or the like, a single-wavelength laser in an infrared region or a visible region oscillated from a DFB (Distributed feedback) semiconductor laser or a fiber laser, for example, erbium (Er) (or erbium and ytterbium (Yb)) Both of them may be amplified by a doped fiber amplifier, and a high wavelength converted to ultraviolet light using a nonlinear optical crystal may be used.
[0059]
In addition, the application of the exposure apparatus is not limited to the exposure apparatus for manufacturing a semiconductor, and for example, manufactures an exposure apparatus for a liquid crystal that exposes a liquid crystal display element pattern of a square glass plate and a thin film magnetic head. Can be widely applied to an exposing apparatus.
[0060]
When a linear motor is used for the wafer stage or the reticle stage, either an air levitation type using an air bearing or a magnetic levitation type using Lorentz force or reactance force may be used. Further, the stage may be of a type that moves along a guide, or may be a guideless type in which a guide is not provided.
[0061]
When a planar 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 stage moving surface side (base). May be provided.
[0062]
Further, the reaction force generated by the movement of the wafer stage may be mechanically released to the floor (ground) by using a frame member as described in JP-A-8-166475. The present invention is also applicable to an exposure apparatus having such a structure.
[0063]
Further, the reaction force generated by the movement of the reticle stage may be mechanically released to the floor (ground) using a frame member as described in JP-A-8-330224. The present invention is also applicable to an exposure apparatus having such a structure.
[0064]
As described above, the exposure apparatus according to the embodiment of the present application allows various subsystems including each component listed in the claims of the present application to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy, It is manufactured by assembling. 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 exposure apparatus from the various subsystems 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, the degree of cleanliness, and the like are controlled.
[0065]
As shown in FIG. 10, in the semiconductor device, a step 301 for designing the function and performance of the device, a step 302 for manufacturing a mask (reticle) based on the design step, a step 303 for manufacturing a substrate which is a base material of the device It is manufactured through a substrate processing step 304 of exposing a mask pattern to a substrate by the exposure apparatus EX of the above-described embodiment, a device assembling step (including a dicing step, a bonding step, and a package step) 305, an inspection step 306, and the like.
[0066]
【The invention's effect】
As described above, according to the exposure apparatus of the present invention, since the exposure apparatus includes the film structure, it is possible to suppress the invasion of the light-absorbing substance into the inside of the exposure apparatus, and to reduce the vibration propagation between the elements constituting the exposure apparatus. Since it is suppressed, stable optical characteristics can be obtained. Further, according to the exposure method of the present invention, pattern accuracy can be improved.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an exposure apparatus shown as a first embodiment of the present invention.
FIG. 2 is an enlarged sectional view of a working distance section of the exposure apparatus shown as the first embodiment of the present invention.
FIG. 3 is an enlarged sectional view of a projection optical system of an exposure apparatus shown as a second embodiment of the present invention.
FIG. 4 is an enlarged sectional view of a projection optical system of an exposure apparatus shown as a modification of the second embodiment of the present invention.
FIG. 5 is an enlarged sectional view of a projection optical system of an exposure apparatus shown as another modification of the second embodiment of the present invention.
FIG. 6 is an enlarged cross-sectional view between a reticle operation unit and a projection optical system of an exposure apparatus shown as a third embodiment of the present invention.
FIG. 7 is an enlarged cross-sectional view between a reticle operating unit and a projection optical system of an exposure apparatus shown as a modification of the third embodiment of the present invention.
FIG. 8 is an enlarged side view of a reticle operation unit of an exposure apparatus shown as a fourth embodiment of the present invention.
FIG. 9 is an enlarged cross-sectional view of a wafer operation unit of an exposure apparatus shown as a fifth embodiment of the present invention.
FIG. 10 is a flowchart illustrating an example of a semiconductor device manufacturing process.
[Explanation of symbols]
10 Exposure equipment
22 Reticle operation unit (element)
23 Wafer operation unit (element)
26 Reticle room (element)
27 Lens tube (element)
29 reticle load lock room (element)
50 Gas supply / exhaust system (gas supply mechanism)
71 Isolation mechanism (film structure)
72a first film (first thin film member)
72b second film (second thin film member)
73a First holding member (first holding section)
73b Second holding member (second holding portion)
76 Gas supply port (gas supply port)
77 Gas outlet (gas outlet)
R reticle (mask)
S1 space
S3 space

Claims (13)

An exposure apparatus main body that transfers a pattern of a mask onto a substrate; and an exposure apparatus including an isolation mechanism that isolates a predetermined space in the exposure apparatus main body from the outside air.
The separating mechanism includes a first thin-film member, a second thin-film member provided at a predetermined distance from the first thin-film member, and a first thin-film member and the second thin-film member. An exposure apparatus comprising: a gas sealed in a space between the two. The separation mechanism includes a first holding unit that holds the first thin film member, a second holding unit that holds the second thin film member, and a first holding unit that holds the first thin film member and the second thin film member. The exposure apparatus according to claim 1, further comprising a gas supply port that supplies the gas to a space therebetween. Either the first holding part or the second holding part has a gas exhaust port for exhausting the gas supplied to the space between the first thin film member and the second thin film member. The exposure apparatus according to claim 2, further comprising: 4. The gas supply mechanism according to claim 1, further comprising: a gas supply mechanism that supplies a gas that transmits exposure light for transferring the pattern of the mask onto the substrate in the predetermined space. Exposure apparatus according to 1. The gas supplied into the predetermined space and the gas sealed in a space between the first thin film member and the second thin film member are the same, wherein Exposure apparatus according to the above. The first thin-film member has a function of blocking intrusion of the first substance, out of the plurality of substances included in the outside air, into the predetermined space,
The second thin film member has a function of blocking intrusion of a second substance different from the first substance among a plurality of substances contained in the outside air into the predetermined space. The exposure apparatus according to claim 1. The exposure apparatus according to any one of claims 1 to 6, wherein the first thin film member and the second thin film member are provided in this order from the predetermined space side. The first thin film member includes a first thin film made of a first material having elasticity, a second thin film made of a second material that blocks the invasion of the outside air into the predetermined space, and a metal film. Formed,
The exposure apparatus according to claim 7, wherein the second thin film member is formed of the first thin film. An exposure method for transferring the mask pattern onto the substrate using the exposure apparatus according to claim 1. A film structure that isolates a predetermined space in the exposure apparatus main body that transfers a pattern of a mask onto a substrate from outside air,
The film structure includes a first thin-film member, a second thin-film member provided at a predetermined distance from the first thin-film member, and the first thin-film member and the second thin-film member. And a gas sealed in a space between the film structures. The film structure according to claim 10, wherein the first thin film member and the second thin film member are formed by laminating a plurality of thin films. The film structure according to claim 11, wherein the first thin film member and the second thin film member are different in the type of thin film to be laminated. The film structure according to any one of claims 10 to 12, wherein the film structure is arranged between a plurality of elements of the exposure apparatus main body, the vibration transmission between the elements being suppressed.

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