JP2003133198A - Optical device, exposure device, and method for manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical device having a stable optical performance by preventing the vibration and position shift of a reflecting material, due to the effect of a gas flow introduced into a space. SOLUTION: The optical device, having a reflection member FM with two reflection surfaces M1 and M2 forming a prescribed angle with each other in the space a prescribed gas is introduced into, has a gas inlet device 128 which introduces the prescribed gas into the space that the states flow of the prescribed gas at two reflecting surfaces M1 and M2 become substantially equal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a microdevice such as a semiconductor integrated circuit, an image pickup device such as a CCD, a liquid crystal display, or a thin film magnetic head using a lithography technique, and an exposure apparatus used during the manufacturing. And a light source device suitable for the exposure apparatus.

[0002]

2. Description of the Related Art In recent years, with the miniaturization of circuit patterns of microdevices such as semiconductor integrated circuits, the wavelength of illumination light (exposure beam) for exposure used in exposure apparatuses such as steppers has been shortened year by year. There is. That is, as the exposure beam, KrF excimer laser light (wavelength: 248 nm) has become the mainstream in place of i-line (wavelength: 365 nm) and g-line (wavelength: 436 nm) of a mercury lamp that has been mainly used in the past. And further shorter wavelength ArF
Excimer laser light (wavelength: 193 nm) is being put to practical use. Further, for the purpose of further shortening the wavelength of the exposure beam, it has been attempted to use a halogen molecule laser such as an F ₂ laser (wavelength: 157 nm).

Beams having a wavelength of about 190 nm or less belong to the vacuum ultraviolet region, and these beams do not transmit air. This is because the energy of the beam is absorbed by substances such as oxygen molecules, water molecules and carbon dioxide molecules contained in the air (hereinafter referred to as light absorbing substances).

Therefore, in an exposure apparatus using an exposure beam in the vacuum ultraviolet region, in order to reach the substrate to be exposed with a sufficient illuminance, the light absorbing substance is reduced or eliminated from the space on the optical path of the exposure beam. There is a need to. For example, in an exposure apparatus using an F ₂ laser, it is necessary to fill (purge) all the spaces on the optical path of the exposure beam with a high-purity inert gas.

[0005]

By the way, when introducing the filling gas into the space on the optical path, the optical member may be vibrated or displaced due to the influence of the gas flow.
In particular, in a reflecting member having two reflecting surfaces forming a predetermined angle with each other, a difference in a gas flow state between the two reflecting surfaces causes a difference in a force received by each reflecting surface from the gas flow. The above-mentioned vibration and displacement are likely to occur. When such vibration or displacement occurs in the reflecting member, the light does not reach the desired position correctly, and the optical performance deteriorates.

The present invention has been made in view of the above circumstances, and prevents the reflection member from vibrating or shifting due to the influence of the flow of gas introduced into the space, and has an optical device having stable optical performance. The purpose is to provide. Another object of the present invention is to provide an exposure apparatus that can improve the exposure accuracy, and a device manufacturing method that can improve the accuracy of the formed pattern.

[0007]

In order to solve the above-mentioned problems, an optical device according to the present invention has two reflecting surfaces (M1, M1) which form a predetermined angle in a space into which a predetermined gas is introduced.
In the optical device (PL) in which the reflecting member (FM) having M2) is arranged, the flow of the predetermined gas is substantially the same in the two reflecting surfaces (M1, M2) in the space. A gas introduction device (1 for introducing the predetermined gas
28) is provided. This optical device (P
In L), the state of the flow of the predetermined gas introduced into the space is almost the same at the two reflecting surfaces (M1, M2) of the reflecting member (FM), so that the effect of the gas flow is two reflections. The surfaces (M1, M2) are almost the same, and the reflection member (FM)
Vibration and displacement of the can be prevented. Here, as the "reflecting member having two reflecting surfaces forming a predetermined angle with each other", one having two reflecting surfaces formed on one member and one having two reflecting surfaces formed on different members respectively Including both.

In this case, it is preferable that the predetermined gas flow state includes the flowing direction of the predetermined gas in each of the two reflecting surfaces (M1, M2).

Further, the gas introducing device (128) includes a surface including one of the two reflecting surfaces (M1 and M2) and a surface including the other reflecting surface (M2). The ridge line (127) from any one of the front side, the back side, and the side surface of the ridge line (127) formed by intersecting
The predetermined gas may be introduced so as to flow toward. This makes it possible to easily make the predetermined gas flow state substantially the same between the two reflecting surfaces (M1, M2) of the reflecting member (FM). Here, the "ridge line" includes both the one formed by the reflecting surface and the one formed by the surface including the reflecting surface.

Further, the gas introduction device (128) has the flow rate difference that suppresses the turbulent flow on the two reflecting surfaces (M1, M2), and the predetermined amount is directed toward the two reflecting surfaces (M1, M2). It is preferable to have a plurality of inlets (126) for introducing the gas. As a result, two reflecting surfaces (M1, M2)
The occurrence of turbulence in the is suppressed, and vibration and displacement of the reflection member (FM) are prevented.

In this case, the gas introduction device (1
28) may have a fin (140) arranged at an inlet (126) for introducing the predetermined gas into the space. This further suppresses the occurrence of turbulence on the two reflecting surfaces (M1, M2).

A turbulence suppressing member (135, 13) for suppressing turbulence of the flow of the predetermined gas in the space.
8) is preferable. This suppresses the generation of vortices and turbulence in the space, and prevents the reflection member (FM) from vibrating and being displaced.

In this case, the disturbance suppressing member (1
35, 138) preferably has a surface continuous with the two reflecting surfaces (M1, M2). This suppresses the generation of vortices and turbulence on the two reflecting surfaces (M1, M2).

Further, the disturbance suppressing member (135) may be a supporting member (135) for supporting the reflecting mirror. Thereby, the disturbance suppressing member (135) can be efficiently arranged in the space.

Further, the exposure apparatus (10) of the present invention comprises an illumination optical system (21) for illuminating a mask (R) on which a pattern is formed with a beam, and the pattern of the mask (R) on a substrate (W). At least one of the projection optical system (PL) and the projection optical system to be transferred to is configured by the above-mentioned optical device.

Further, the present invention is a method of manufacturing a device including a lithography process, wherein the device is manufactured using the above-described exposure apparatus (10) in the lithography process.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 shows an overall configuration of a reduction projection exposure apparatus 10 for manufacturing a semiconductor device according to an embodiment, which includes the optical apparatus according to the present invention as a projection optical system. Further, in FIG. 1, an XYZ rectangular coordinate system is adopted. XYZ
In the orthogonal coordinate system, the X axis and the Y axis are set so as to be parallel to the wafer stage WS that holds the wafer W as a substrate (photosensitive substrate), and the Z axis is a direction orthogonal to the wafer stage WS. Is set to. Actually, X in the figure
In the YZ orthogonal coordinate system, the XY plane is set to a plane parallel to the horizontal plane, and the Z axis is set to the vertical direction.

The exposure apparatus according to this embodiment uses an F ₂ laser light source as an exposure light source. Further, one shot area on the wafer W is obtained by synchronously scanning the reticle R and the wafer W in a predetermined direction relative to an illumination area having a predetermined shape on the reticle R as a mask (projection original plate). In addition, a step-and-scan method for sequentially transferring the pattern image of the reticle R is adopted. In such a step-and-scan type exposure apparatus, the pattern of the reticle R can be exposed in an area on the substrate (wafer W) wider than the exposure field of the projection optical system.

In FIG. 1, an exposure apparatus 10 includes a laser light source 20, an illumination optical system 21 for illuminating a reticle R with an exposure beam IL from the laser light source 20, and an exposure beam IL emitted from the reticle R onto a wafer W. The projection optical system PL for projecting, and a main controller (not shown) that controls the entire apparatus are provided.

The laser light source 20 has, for example, an oscillation wavelength 157.
It has an F ₂ laser which outputs a pulsed ultraviolet light of nm. Further, the laser light source 20 is provided with a light source control device (not shown), and the light source control device has an oscillation center wavelength and a spectrum half width of the pulsed ultraviolet light emitted in response to an instruction from the main control device. Control, pulse oscillation trigger control, gas control in the laser chamber, etc. are performed.

The pulsed laser light (illumination light) from the laser light source 20 is deflected by the deflection mirror 30 and enters the variable light attenuator 31 as an optical attenuator. Variable dimmer 31
The extinction rate can be adjusted stepwise or continuously in order to control the exposure dose for the photoresist on the wafer. The illumination light emitted from the variable light attenuator 31 is deflected by the optical path deflecting mirror 32, and then reaches the second fly-eye lens 36 through the first fly-eye lens 33, the zoom lens 34, and the vibrating mirror 35 in this order. . On the exit side of the second fly-eye lens 36, a switching revolver 37 for the aperture stop of the illumination optical system for setting the size and shape of the effective light source as desired is arranged. In the present embodiment, in order to reduce the light amount loss at the aperture stop of the illumination optical system, the size of the light flux to the second fly-eye lens 36 by the zoom lens 34 is variable.

The light flux emitted from the aperture of the illumination optical system aperture stop illuminates an illumination field stop (reticle blind) 41 through a condenser lens group 40. The illumination field stop 41 is disclosed in JP-A-4-196513 and the corresponding US Pat. No. 5,473,410.

The light from the illumination field stop 41 is guided onto the reticle R via an illumination field stop image forming optical system (reticle blind image forming system) including deflection mirrors 42 and 45 and lens groups 43, 44 and 46. On the reticle R, an illumination area which is an image of the opening of the illumination field stop 41 is formed. Light from the illumination area on the reticle R is guided onto the wafer W via the projection optical system PL, and on the wafer W, the reticle R is lit.
A reduced image of the pattern in the illuminated area of is formed. The reticle stage RS holding the reticle R is two-dimensionally movable in the XY plane, and its position coordinates are measured and controlled by the interferometer 50. The wafer stage WS that holds the wafer W is also two-dimensionally movable in the XY plane, and its position coordinates are measured and controlled by the interferometer 51. With these, reticle R
Also, the wafer W can be synchronously scanned with high accuracy. An illumination optical system 21 is configured by the laser light source 20 to the illumination field stop imaging optical system described above.

2 and 3 each show an example of the configuration of the projection optical system PL. In this embodiment, a refraction type projection optical system is adopted. A configuration example of the refractive projection optical system will be described with reference to FIGS. In the configuration example of FIG. 2, the projection optical system PL includes a refraction type first imaging optical system K1 that forms an intermediate image of a pattern on a reticle R as a projection original plate, and an intermediate image formed by the first imaging optical system K1. Refraction-type second imaging optical system K for re-imaging the image (secondary image) of
2 and a refraction-type third imaging optical system K for re-imaging the secondary image by the second imaging optical system K2 on the wafer W as a work.
3 and 3. Here, the first imaging optical system K1 and the second imaging optical system K1
A reflecting surface M1 for bending the optical path for deflecting the optical path by 90 ° is arranged in the optical path between the imaging optical system K2 and the second imaging optical system K2 and the third imaging optical system K3. A reflecting surface M2 for bending the optical path for deflecting the optical path by 90 ° is disposed in the optical path between and. These reflecting surfaces M1 and M2 are provided on the optical path bending member FM.

The first image forming optical system K1 has an optical axis Ax1.
It has a plurality of lens components arranged along with, and forms an intermediate image under the reduction magnification of about 1 / 1.5 to 1/3. The second imaging optical system K2 includes a single or a plurality of lens components arranged along the optical axis Ax2 and a concave reflecting mirror C.
M and M, and forms an intermediate image (secondary image) by the first imaging optical system K1 under substantially the same magnification. And
The third imaging optical system K3 has a plurality of lens components arranged along the optical axis Ax3, and is approximately 1 / 1.5 to 1 / 1.5.
Under a reduction magnification of about 3, the first and second imaging optical systems K
An image of a secondary image (a tertiary image) of 1 and K2 is formed on the wafer W. In this example, the optical axis Ax1 and the optical axis Ax3 coincide with each other, but the optical axis Ax1 and the optical axis Ax3 may be parallel to each other and may not coincide with each other, or the optical axis Ax2.
Need not be orthogonal to the optical axis Ax1 or the optical axis Ax3.

In the configuration example of FIG. 3, the projection optical system PL is a catadioptric type first imaging optical system K1 for forming an intermediate image of a pattern on a reticle R as a projection original plate, and a first imaging. It has a refraction type second imaging optical system K2 for re-imaging an intermediate image by the optical system K1 on a wafer W as a work. Here, the reticle R and the first imaging optical system K
In the optical path between the first imaging optical system K1 and the second imaging optical system K2, a reflecting surface M1 for bending the optical path for deflecting the optical path by 90 ° is arranged. A reflecting surface M2 for bending the optical path for deflecting the optical path by 90 ° is arranged in the optical path, that is, in the vicinity of the intermediate image. These reflecting surfaces M1 and M2 are provided on the optical path bending member FM.

The first image forming optical system K1 has a plurality of lens components arranged along the optical axis Ax2 and a concave reflecting mirror CM, and an intermediate image at a substantially equal magnification or a slightly reduced magnification. To form. The second imaging optical system K2 has a plurality of lens components arranged along an optical axis Ax3 orthogonal to the optical axis Ax2 and a variable aperture stop AS for controlling the coherence factor, and from the intermediate image. The image of the intermediate image, that is, the secondary image is formed based on the light of 1. Here, the optical axis Ax2 of the first imaging optical system K1 is bent by 90 ° by the optical path bending reflecting surface M1 to define the optical axis Ax1 between the reticle R and the reflecting surface M1. In this example, the optical axis Ax1 and the optical axis Ax3 are parallel to each other, but do not match. In this example, the optical axis Ax
1 and the optical axis Ax3 may be arranged so as to coincide with each other. Further, the angle formed by the optical axis Ax1 and the optical axis Ax2 is 90
It may be an angle different from °, preferably an angle obtained by rotating the concave reflecting mirror CM counterclockwise. At this time, the bending angle of the optical axis on the reflecting surface M2 is set to the reticle R and the wafer W.
It is preferable to set so that and are parallel to each other.

Now, returning to FIG. 1, when the light in the vacuum ultraviolet region is used as the exposure beam like the F ₂ laser light (wavelength: 157 nm) used in this embodiment, oxygen, water vapor, It is necessary to exclude a gas such as a hydrocarbon gas having a strong absorption characteristic for light in the wavelength band (hereinafter, appropriately referred to as “absorptive gas”). Therefore, in this embodiment, the illumination light path (the laser light source 20 to the reticle R) and the projection light path (the reticle R to the wafer W) are shielded from the external atmosphere, and the light paths are converted into vacuum ultraviolet light. On the other hand, it is filled with nitrogen, helium, argon, neon, krypton, or other gas as a specific gas having a property of low absorption, or a mixed gas thereof (hereinafter referred to as "low absorption gas" or "specific gas" as appropriate). ing.

Specifically, the optical path from the laser light source 20 to the variable dimmer 31 is blocked from the external atmosphere by the casing 60, and the optical path from the variable dimmer 31 to the illumination field stop 41 is blocked from the external atmosphere by the casing 61. The illumination and field stop imaging optical system is shielded from the external atmosphere by the casing 62, and the specific gas is filled in the optical paths thereof. The casing 61 and the casing 62 are connected by the casing 63. In addition, the projection optical system P
Also in L itself, the lens barrel 69 serves as a casing, and the internal light path thereof is filled with the specific gas.

The casing 64 shields the space between the casing 62 housing the illumination field diaphragm imaging optical system and the projection optical system PL from the external atmosphere, and holds the reticle R inside the reticle stage. Contains RS. The casing 64 is provided with a door 70 for loading and unloading the reticle R, and the outside of the door 70 prevents the atmosphere in the casing 64 from being polluted when the reticle R is loaded and unloaded. A gas replacement chamber 65 is provided for this purpose. The gas replacement chamber 65 is also provided with a door 71, and the reticle is delivered to and from the reticle stocker 66 that stores a plurality of types of reticles.

The casing 67 is a projection optical system PL.
The space between the wafer W and the wafer W is shielded from the external atmosphere, and the wafer stage WS for holding the wafer W via the wafer holder 80, the position (focus position) in the Z direction of the surface of the wafer W, and the inclination thereof are provided inside the space. Oblique incidence type autofocus sensor 81 for detecting an angle, off-axis type alignment sensor 82, wafer stage WS
A surface plate 83 and the like on which is mounted are stored. A door 72 for loading / unloading the wafer W is provided in the casing 67.
A casing 6 is provided outside the door 72.
A gas replacement chamber 68 is provided to prevent the atmosphere inside 7 from being contaminated. This gas replacement chamber 68 has a door 73
The wafer W is carried in and out of the apparatus through the door 73.

Nitrogen or helium is preferably used as the specific gas filled in each optical path. Nitrogen has a wavelength of 1
The light absorption characteristic is strong with respect to light with a wavelength of about 50 nm or less, and helium has a strong light absorption characteristic with respect to light with a wavelength of about 100 nm or less. Helium has a thermal conductivity about 6 times that of nitrogen, and the amount of fluctuation in the refractive index with respect to changes in atmospheric pressure is about 1/8 of that of nitrogen. Therefore, particularly high transmittance and stability of the imaging characteristics of the optical system and cooling properties are possible. And is excellent at. Helium may be used as the specific gas for the lens barrel of the projection optical system PL, and nitrogen may be used as the specific gas for the other optical paths (for example, the illumination optical path from the laser light source 20 to the reticle R).

Here, the casings 61, 62, 64, 6
7, each of the air supply valves 100, 101, 102, 1
03 are provided, and these air supply valves 100 to 103 are provided.
Is connected to an air supply line connected to a gas supply device (see FIG. 4, reference numeral 123). Also, the casings 61 and 6
Exhaust valves 110, 11 are provided at 2, 64, 67, respectively.
1, 112, 113 are provided, and these exhaust valves 110-113 are connected to a gas exhaust device (not shown) via exhaust pipe lines, respectively. The specific gas from the gas supply device is controlled to a predetermined target temperature by a temperature adjusting device (not shown). When helium is used as the specific gas, the temperature adjusting device is preferably arranged near each casing.

Similarly, the gas replacement chambers 65 and 68 are also provided with air supply valves 104 and 105 and exhaust valves 114 and 115, and the air supply valves 104 and 105 are connected to the exhaust valve 114 via an air supply line. , 115 are connected to the gas supply device via exhaust pipes, respectively. Furthermore, the projection optical system PL
The lens barrel 69 is also provided with an air supply valve 106 and an exhaust valve 116, and the air supply valve 106 is connected to the exhaust valve 1 via an air supply line.
Reference numeral 16 is connected to the gas supply device via an exhaust pipe line.

It should be noted that dust (particles) such as a HEPA filter or ULPA filter is removed from the air supply line provided with the air supply valves 100 to 106 and the exhaust line provided with the exhaust valves 110 to 116. Filter for
A chemical filter for removing absorbing gas such as oxygen is provided.

In the gas replacement chambers 65 and 68,
It is necessary to perform gas replacement at the time of reticle exchange or wafer exchange. For example, when replacing the reticle, the door 71 is opened and the reticle is moved from the reticle stocker 66 to the gas replacement chamber 6
5, the door 71 is closed and the gas replacement chamber 65 is filled with the specific gas, then the door 70 is opened and the reticle is placed on the reticle stage RS. When the wafer is replaced, the door 73 is opened to carry the wafer into the gas replacement chamber 68, and the door 73 is closed to fill the gas replacement chamber 68 with the specific gas. Thereafter, the door 72 is opened and the wafer is placed on the wafer holder 80. The reverse procedure is used for reticle carry-out and wafer carry-out. Also, the gas replacement chamber 65,
In the gas replacement of 68, the atmosphere in the gas replacement chamber may be depressurized and then the specific gas may be supplied from the air supply valve.

In the casings 64 and 67,
There is a possibility that the gas that has undergone the gas replacement by the gas replacement chambers 65 and 68 may be mixed, and a considerable amount of absorbing gas such as oxygen may be mixed into the gas of the gas replacement chambers 65 and 68. high. Therefore, it is desirable to perform gas replacement at the same timing as gas replacement in the gas replacement chambers 65 and 68. Further, it is preferable that the casing and the gas replacement chamber are filled with a specific gas having a pressure higher than the pressure of the external atmosphere.

FIG. 4 shows the projection optical system PL shown in FIG.
FIG. 3 is a schematic cross-sectional view showing the flow of a specific gas in the lens barrel of FIG. In the present embodiment, the specific gas is specified in the lens barrel 69 so that the flow state of the specific gas in the lens barrel 69 of the projection optical system PL is substantially the same in the two reflecting surfaces M1 and M2 of the optical path bending member FM described above. Gas is introduced.

That is, in FIG. 4, the lens barrel 69 has a first axis provided with the optical axes Ax1 and Ax3 as central axes.
It includes a lens barrel 120 and a second lens barrel 121 provided with the optical axis Ax2 as a central axis so as to intersect with the first lens barrel 120, and an optical path bending member in the internal space of these lens barrels. The first lens barrel 120 and the second lens barrel 1 in which the FM is arranged
The specific gas introduced from the second lens barrel 121 mainly flows in the intersection with 21. Second lens barrel 1
21 is provided with a plurality of introduction nozzles 122 for introducing gas, and a part of the specific gas supplied from the gas supply device 123 to the lens barrel 69 via the air supply valve 106 and the air supply pipeline 125 is provided. , The inlets 12 of the plurality of inlet nozzles 122
It is introduced into the second lens barrel 121 via 6 and then flows toward the first lens barrel 120. The gas supply device 123, the air supply valve 106, the air supply pipe 125, the plurality of introduction nozzles 122, and the like described above constitute a gas introduction device 128 that introduces a specific gas into the space inside the lens barrel 69. In addition, in the inner space of the lens barrel, other than this intersection,
The specific gas is appropriately introduced through another inlet.

The plurality of introduction nozzles 122 are arranged on the front side (concave reflecting mirror CM side) of the ridge line 127 formed by intersecting surfaces including the two reflecting surfaces M1 and M2 of the optical path bending member FM, and the ridge line 127. Two reflective surfaces M across
They are separately arranged on the respective sides of 1 and M2. Further, the plurality of introduction nozzles 122 are arranged so as to be inclined with respect to the optical axis Ax3 so that the respective introduction ports 126 face a position slightly ahead of the ridge line 127 of the optical path bending member FM. In addition, the distance from the optical path bending member FM to the plurality of introduction nozzles 122, the arrangement angle of the plurality of introduction nozzles 122, and the number of arrangement of the introduction nozzles 122 are stable such that the specific gas introduced from the plurality of introduction nozzles 122 is less disturbed. In such a state, it is determined that the optical path bending member FM is reached.

FIG. 5 is a view taken along the line AA in FIG.
An example of arrangement of the plurality of introduction nozzles 122 described above is shown. In FIG. 5, the plurality of introduction nozzles 122 are arranged such that the specific gas is introduced toward the two reflecting surfaces M1 and M2 with a flow rate difference that suppresses turbulent flow in at least two reflecting surfaces M1 and M2. It is set up. That is, the plurality of introduction nozzles 122 are arranged symmetrically on each side of the two reflection surfaces M1 and M2 of the optical path bending member FM (three in this case), with the ridge line 127 interposed therebetween. Further, the opening areas of the respective introduction nozzles 122 (introduction ports 126) have the same size so that the specific gas having substantially the same flow rate is introduced into the respective sides of the two reflecting surfaces M1 and M2.

Returning to FIG. 4, as described above, the first lens barrel 1
At the intersection of 20 and the second lens barrel 121, each of the introduction ports 126 of the plurality of introduction nozzles 122 has an optical path bending member F.
Since it faces a position slightly ahead of the ridgeline 127 of M, the specific gas introduced from the plurality of inlets 126 merges before the ridgeline 127, and then moves to the second position along the optical axis Ax3.
It flows from the lens barrel 121 toward the first lens barrel 120. After that, the specific gas branches off along the ridge 127 and flows along each of the two reflecting surfaces M1 and M2 of the optical path bending member FM. From the plurality of inlets 126, the specific gas of substantially the same flow rate is introduced to the respective sides of the two reflecting surfaces M1 and M2 of the optical path bending member FM, and therefore, to the respective surfaces of the two reflecting surfaces M1 and M2. The states of the flow of the specific gas along the two reflection surfaces M1 and M2 are substantially the same.

In this embodiment, since the state of the flow of the specific gas is substantially the same on the two reflecting surfaces M1 and M2 of the optical path bending member FM, the flow of the specific gas on the two reflecting surfaces M1 and M2 is the same. The influence is less biased, and the influence of the flow is substantially the same on the two reflecting surfaces M1 and M2. That is, the two reflecting surfaces M1 and M2 both receive the force of the specific gas flowing along the optical axis Ax3, and the direction of the force is mainly in the direction substantially parallel to the optical axis Ax3. Also,
The flow rates of the specific gas flowing through the two reflecting surfaces M1 and M2 are substantially the same, and at least the turbulence is suppressed, so that the magnitude of the force exerted by the specific gas on the reflecting surfaces M1 and M2 is substantially the same. is there. In this way, the influence of the flow of the specific gas, especially the force received from the flow, is reflected by the two reflecting surfaces M1,
The optical path bending member F becomes the same in M2.
Vibration and displacement of M are prevented.

6 and 7 are schematic sectional views showing an example of a supporting member for supporting the optical path bending member FM shown in FIG. In FIG. 6, the optical path bending member FM is supported by a flat plate-shaped supporting member 130. That is, one end of the support member 130 is fixed to the back surface 131 of the optical path bending member FM, and the other end of the support member 130 is fixed to the inner peripheral surface of the lens barrel 69, whereby the optical path bending member FM is fixed to the lens barrel 6.
It is positioned in the inner space of 9.

In the case of FIG. 6, the specific gas flowing along each of the two reflection surfaces M1 and M2 of the optical path bending member FM is swirled or disturbed by the step between the back surface 131 of the optical path bending member FM and the support member 130. Generate a flow. Such vortices and turbulent flow are likely to cause vibration and displacement of the optical path bending member FM. Therefore, in the present embodiment, as shown in FIG. 7, the support member of the optical path bending member FM is provided so as to suppress the disturbance of the flow of the specific gas.

That is, in FIG. 7, the support member 132 of the optical path bending member FM has the same shape and size as the back surface 131 of the optical path bending member FM so that no step is formed between the support member 132 and the back surface 131 of the optical path bending member FM. Connection surface 1
33 is formed. Further, the support member 132
Is the rear surface 1 of the optical path bending member FM.
It has surfaces 134 and 135 formed so as to be continuous (smoothly connected) with the two reflecting surfaces M1 and M2 of the optical path bending member FM, respectively, when connected to 31.
The surfaces 134 and 135 are formed, for example, in a curved shape so that swirl, turbulence, or a separation region does not occur in the specific gas flowing along the two reflecting surfaces M1 and M2 of the optical path bending member FM. .

In the case of FIG. 7, the specific gas flowing along each of the two reflecting surfaces M1 and M2 of the optical path bending member FM does not generate a large vortex, turbulence, or a separation region, and the specific gas of the supporting member 132 does not change. Flows along surfaces 134 and 135. Therefore, it is possible to suppress the vibration and displacement of the optical path bending member FM.

Further, in this case, since there is no step between the optical path bending member FM and the supporting member 132, it is difficult for the gas to stagnate and stay. The stagnation of the gas on the optical path causes the absorption gas to remain, which easily leads to a reduction in the illuminance of the exposure beam and unevenness of the illuminance. Note that, as shown in FIG. 7, the specific gas flowing along the two reflecting surfaces M1 and M2 of the optical path bending member FM and the surfaces 134 and 135 of the supporting member 132 does not significantly change the direction of the flow. The exhaust port 136 (exhaust pipe line) is connected to the support member 1 so that it is discharged.
It may be provided around 32. As a result, stagnation of gas can be reliably prevented.

FIG. 8 shows an optical path bending member F shown in FIG.
FIG. 6 is a view of M and the support member 132 as viewed in a light incident direction (Z direction) on a reflecting surface M1. As described above, in this embodiment, the specific gas introduction nozzle 122 shown in FIG. 4 is used.
Is disposed on the front side of the ridgeline 127 of the optical path bending member FM, the specific gas flows from the front side of the ridgeline 127 toward the ridgeline 127. Therefore, the specific gas is branched off along the ridge 127, and the state of the flow of the specific gas is changed to the two reflecting surfaces M1 and M2 of the optical path bending member FM (FIG. 7).
(See) has the advantage that it tends to be almost the same. However, the flow direction of the specific gas is not limited to the direction shown in FIG. 8 and may be another direction.

For example, as shown in FIG. 9, a specific gas introduction nozzle is arranged on the side surface side of the ridge line 127 (not shown), and the specific gas is directed from the side surface side of the ridge line 127 of the optical path bending member FM toward the ridge line 127. You may make it flow. In this case, the specific gas flows substantially parallel to the ridge line 127, and the flow state of the specific gas is substantially the same on the two reflecting surfaces M1 and M2 of the optical path bending member FM. Further, as described later, the specific gas may be flown from the back side of the ridgeline 127 of the optical path bending member FM toward the ridgeline 127. In this way, by introducing the specific gas so as to flow toward the ridge line 127 from any one of the front side, the back side, and the side surface side of the ridge line 127 of the optical path bending member FM, 2
The flow rate of the specific gas flowing through the two reflecting surfaces M1 and M2 and the flow direction thereof are substantially the same, and the influence of the flow is substantially the same between the two reflecting surfaces M1 and M2. When the specific gas flows from the side surface side or the back surface side of the ridgeline 127 toward the ridgeline 127, it is preferable to consider so that the optical path bending member FM and its supporting member do not become a flow resistance.

FIG. 10 shows an optical path bending member F for a specific gas.
FIG. 10 is a diagram showing an example in which the optical path bending member FM and its supporting member are configured so as not to resist the flow when flowing from the side surface side of the ridge line 127 of M toward the ridge line 127. In FIG. 10, the support member 137 of the optical path bending member FM is formed with a small cross-sectional area in the flow direction of the specific gas so that the resistance to the flow of the specific gas is reduced. Further, turbulence suppressing members 138 are disposed on both side surfaces of the optical path bending member FM so that the resistance of the optical path bending member FM against the flow of the specific gas is reduced. The turbulence suppressing member 138 has a connecting surface having the same shape and size as the side surface of the optical path bending member FM and the optical path bending member F so that a step is not formed between the disturbance suppressing member 138 and the optical path bending member FM.
It is formed by having two reflecting surfaces M1 and M2 of M and a surface formed so as to be respectively continuous (smoothly connected). Further, the turbulence suppressing member 138 reaches the side surface of the optical path bending member FM with its cross-sectional area gradually increasing from the minimum toward the flow direction of the specific gas, and gradually decreases from the other side surface. Is formed to be the smallest. As described above, by providing the support member and the turbulence suppressing member so that the resistance to the flow of the specific gas is reduced, the generation of the vortex, the turbulence, or the separation region is reliably suppressed.

11 and 12 show an example of the structure of the introduction nozzle 122 for introducing the specific gas shown in FIG. In FIG. 11, a fin 140 is arranged inside the introduction nozzle 122. The fin 140 is
It is made up of plate-shaped members that are combined so as to have a cross-shaped cross section, and is provided so as to extend from the introduction port 126 of the introduction nozzle 122 to the inside. In this case, the fin 140 divides the flow path of the specific gas at the introduction port 126, thereby suppressing the generation of turbulence due to the specific gas introduced through the introduction nozzle 122. The shape, size, and quantity of the fins are not limited to those shown in FIG. 11, and as shown in FIG. 12, a fin 141 in which a plurality of cylindrical plate-shaped members are combined may be used, or a star may be used. A plate-shaped member of a mold may be used.

As described above, in the exposure apparatus 10 of the present embodiment, the two gas-reflecting surfaces M1 and M2 of the optical path bending member FM of the projection optical system PL have substantially the same flow state of the specific gas, so The influence of the gas flow is almost the same on the two reflecting surfaces M1 and M2, and the vibration and displacement of the optical path bending member FM are prevented. Moreover, since the occurrence of a phenomenon that exerts a force on the optical path bending member FM such as a vortex, a turbulence, or a separation region is suppressed, the above-described vibration and displacement are less likely to occur. Therefore, the exposure beam
Stably and correctly, the pattern image of the reticle R is accurately transferred (exposed) onto the wafer W.

FIG. 13 shows another form of the gas introduction device in the projection optical system PL described above. In FIG. 13, a lens barrel 69 includes a first lens barrel 151 provided with the optical axis Ax1 and the optical axis Ax3 as a central axis, and the first lens barrel 150.
A second lens barrel 151 provided with the optical axis Ax2 as a central axis so as to intersect with the optical axis Ax2, and the inner space of the second lens barrel 151 centered on the optical axis Ax2 by the partition member 152 is the other lens barrel. It is isolated from the interior space of. The partition member 152 is mainly made of a transmissive member that transmits an exposure beam (a parallel flat plate made of fluorite, fluorine-doped quartz, glass, plastic, or the like), and is connected to the inner peripheral surface of the second lens barrel 151 as smoothly as possible. Formed and arranged as follows. Further, a plurality of introduction nozzles 154 are arranged on the back side of the ridge line 127 of the optical path bending member FM supported by the support member 153, and the gas supply device 123, the air supply valve 106, the air supply pipeline 125, and the plurality of gas supply devices 123. Introduction nozzle 154
Through the ridge line 12 of the optical path bending member FM.
It is configured so as to flow from the back side of 7 toward the ridge line 127. A gas introduction device 155 is configured by the gas supply device 123, the air supply valve 106, the air supply pipe 125, the partition member 152, the plurality of introduction nozzles 154 and the like described above.

In the case of FIG. 13, the internal space of the second lens barrel 151 surrounding the optical path bending member FM is isolated, and the permeated gas is introduced and flows along the axial direction of the second lens barrel 151. The flow is easy, and the generation of vortices, turbulence, separation regions, etc. is suppressed not only around the optical path bending member FM but also in the entire inner space of the second lens barrel 151. As a result, vibration and displacement of the optical path bending member FM are reliably prevented. The partition member 152 only needs to reduce the resistance of the specific gas flowing in the inner space of the second lens barrel 151, and does not need to completely isolate the second lens barrel 151 from the inner spaces of the other lens barrels. In addition, the partition member 152
The material is not limited to glass, plastic, or the like, and a gas curtain or the like that partitions a space by using a gas flow may be used.

The operation procedure shown in the above-described embodiment, the shapes and combinations of the respective constituent members, etc. are merely examples, and various changes may be made based on process conditions, design requirements, etc. without departing from the spirit of the present invention. It is possible.

As described above, the "reflecting member having two reflecting surfaces forming a predetermined angle with each other" in the present invention is one in which two reflecting surfaces are formed into one member, and
Both include two reflective surfaces formed on different members. Examples of the two reflecting surfaces formed on different members include, for example, a combination of two reflecting members FM1 and FM2 as shown in FIG. In this case, the ridge 160 is formed by the surface including each reflection surface.

As the gas supply device, for example, a cylinder installed outside the chamber in which the entire exposure apparatus is housed is compressed or compressed with a specific gas (helium gas, nitrogen gas, etc.) in a highly pure state. The thing liquefied and stored is used. Then, if necessary, the specific gas taken out from the cylinder is supplied into each casing or the lens barrel. As the gas exhaust device, for example, a device having a vacuum pump or a device having a cryopump is used. Here, the cryopump is a type of vacuum pump, and is a type in which a sorbent such as activated carbon or synthetic fluoride is cooled with a refrigerant such as nitrogen, and it has an extremely low temperature (10 to 1
A cooled surface (cryopanel) is placed at 5K), and a gas other than gas (H ₂ , He, Ne, for example, N ₂ ,
It adsorbs Ar) and creates a high vacuum.

The specific gas is not limited to helium gas, but nitrogen, argon, or an inert gas such as neon, krypton, xenon, or radon may be used.

In the case of using far ultraviolet rays such as an excimer laser as the projection optical system, a material that transmits far ultraviolet rays such as quartz, fluorite, quartz doped with fluorine, barium fluoride and lithium fluoride is used as a glass material. To use.

The casing, the lens barrel, the supply pipe for the specific gas, and the like are made of a material such as stainless steel (SUS) whose surface roughness is reduced by a treatment such as polishing to suppress the generation of degassing. it can.

Further, the exposure apparatus to which the present invention is applied is a scanning exposure method (for example, a step-and-scan method or the like) in which a mask (reticle) and a substrate (wafer) are moved relative to an exposure illumination beam. The present invention is not limited to this, and a static exposure method, for example, a step-and-repeat method, in which the mask pattern is transferred onto the substrate in a state where the mask and the substrate are substantially stationary may be used. Further, the present invention can be applied to a step-and-stitch type exposure apparatus that transfers a pattern to each of a plurality of shot areas whose peripheral portions overlap each other on a substrate. The projection optical system may be a reduction system, a unity magnification system, or a magnification system, or may be a catadioptric system or a reflection system. Furthermore, the present invention can be applied to, for example, a proximity type exposure apparatus that does not use a projection optical system.

Further, the light source is not limited to the F ₂ laser, but a KrF excimer laser with an oscillation wavelength of 248 nm, an ArF excimer laser with an oscillation wavelength of 193 nm, a wavelength of about 12
A laser emitting light belonging to the vacuum ultraviolet region of 0 nm to about 180 nm, for example, a krypton dimer laser (Kr2 laser) having an oscillation wavelength of 146 nm, an argon dimer laser (Ar2 laser) having an oscillation wavelength of 126 nm, or the like may be used. In addition to the laser light source that emits ultraviolet light,
The light source may be a harmonic generator such as a YAG laser or a semiconductor laser, SOR, a laser plasma light source, or the like.

The exposure apparatus to which the present invention is applied is not limited to the semiconductor device manufacturing, but a liquid crystal display device, a display device, a thin film magnetic head, an image pickup device (CCD, etc.), a micromachine, a DNA chip, etc. For manufacturing microdevices (electronic devices), or for manufacturing photomasks and reticles used in exposure apparatuses.

Further, the present invention can be applied not only to the exposure apparatus but also to other manufacturing apparatus (including an inspection apparatus) provided with the light source device and used in the device manufacturing process.

When a linear motor is used for the wafer stage or reticle stage described above, 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 that does not have a guide.
Further, when a plane motor is used as the drive system of the stage, 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 ( It may be provided on the surface plate or base).

The reaction force generated by the movement of the wafer stage is mechanically fixed to the floor (ground) by using a frame member, as described in JP-A-8-166475.
You may let me escape. The present invention can also be applied to an exposure apparatus having such a structure.

The reaction force generated by the movement of the reticle stage may be mechanically released to the floor (ground) by using a frame member, as described in JP-A-8-330224. The present invention can also be applied to an exposure apparatus having such a structure.

In the exposure apparatus to which the present invention is applied, various subsystems including the constituent elements recited in the claims of the present application are provided so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. It is manufactured by assembling. Before and after this assembly, adjustments to achieve optical precision for various optical systems, adjustments to achieve mechanical precision for various mechanical systems, and various electrical systems to ensure these various types of precision are made. Are adjusted to achieve electrical accuracy. The process of assembling the exposure apparatus from the various subsystems includes mechanical connection, electrical circuit wiring connection, air pressure circuit pipe connection, and the like between the various subsystems. It goes without saying that there is an individual assembly process for each subsystem before the assembly 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 to ensure various accuracies of the exposure apparatus as a whole. It is desirable that the exposure apparatus be manufactured in a clean room where the temperature and cleanliness are controlled.

For semiconductor devices, the process of designing the function / performance of the device, the process of manufacturing a mask (reticle) based on this design step, the process of manufacturing a wafer from a silicon material, and the exposure apparatus described above Wafer processing process of exposing a pattern to a wafer, device assembly process (dicing process, bonding process,
It is manufactured through a packaging process) and an inspection process.

[0071]

As described above, according to the optical device of the present invention, the state of the flow of the predetermined gas introduced into the space is substantially the same on the two reflecting surfaces of the reflecting member.
The influence of the gas flow on the reflecting surface is almost the same between the two reflecting surfaces, and the vibration and the positional displacement of the reflecting member are prevented.
Therefore, stable optical performance can be obtained. Further, since the beam illuminating the mask stably and correctly reaches the wafer, the pattern image of the reticle can be accurately transferred onto the wafer. Further, according to the device manufacturing method of the present invention, it is possible to provide a device in which the accuracy of the formed pattern is improved by improving the exposure accuracy.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of a reduction projection exposure apparatus for manufacturing a semiconductor device according to an embodiment, which includes an optical apparatus according to the present invention as a projection optical system.

FIG. 2 is a diagram showing an example of a configuration of a projection optical system.

FIG. 3 is a diagram showing another example of the configuration of the projection optical system.

FIG. 4 is a schematic cross-sectional view showing the flow of a specific gas in the barrel of the projection optical system.

5 is a view taken along the line AA in FIG.

FIG. 6 is a schematic cross-sectional view showing an example of a support member that supports the optical path bending member.

FIG. 7 is a schematic cross-sectional view showing another example of a support member that supports an optical path bending member.

FIG. 8 is a view on arrow B shown in FIG. 7.

FIG. 9 is a diagram showing an example of flowing a specific gas from another direction.

FIG. 10 is a diagram showing an example in which an optical path bending member and its supporting member are configured so as not to resist the flow of a specific gas.

FIG. 11 is a diagram showing an example of a structure of an introduction nozzle.

FIG. 12 is a diagram showing another example of the structure of the introduction nozzle.

FIG. 13 is a diagram showing another form of the gas introduction device in the projection optical system.

FIG. 14 is a diagram showing an example of a reflecting member in which two reflecting surfaces are formed on different members.

[Explanation of symbols]

R reticle (mask) W wafer (substrate) M1, M2 reflective surface FM reflective member PL projection optical system (optical device) 10 Exposure equipment 21 Illumination optical system 122 Introduction nozzle 126 entrance 127 ridge 128 gas introduction device 140,141 fins 135 Supporting member (disturbance suppressing member) 138 Disturbance suppression member

Claims (10)

[Claims] 1. An optical device in which a reflecting member having two reflecting surfaces forming a predetermined angle with each other is arranged in a space into which a predetermined gas is introduced, wherein a state of a flow of the predetermined gas is the two reflections. An optical device comprising a gas introduction device for introducing the predetermined gas into the space so that the surfaces are substantially the same. 2. The state of the predetermined gas flow is the
The optical device according to claim 1, further comprising a direction in which the predetermined gas flows on each of the two reflecting surfaces. 3. The gas introducing device includes a front side, a back side, and a ridge line formed by intersecting one of the two reflecting surfaces and a surface including the other reflecting surface. The optical device according to claim 1 or 2, wherein the predetermined gas is introduced so as to flow from any one of the side surfaces toward the ridgeline. 4. The gas introducing device has a plurality of inlets for introducing the predetermined gas toward the two reflecting surfaces with a flow rate difference that suppresses turbulence in the two reflecting surfaces. The optical device according to any one of claims 1 to 3, which is characterized. 5. The optical device according to claim 4, wherein the gas introduction device has a fin arranged at an introduction port for introducing the predetermined gas into the space. 6. The optical device according to claim 1, further comprising a turbulence suppressing member that suppresses turbulence of the flow of the predetermined gas in the space. 7. The optical device according to claim 6, wherein the turbulence suppressing member has a surface continuous with the two reflecting surfaces. 8. The optical device according to claim 6, wherein the disturbance suppressing member is a supporting member that supports the reflecting mirror. 9. The method according to claim 1, wherein at least one of an illumination optical system that illuminates a mask on which a pattern is formed with a beam and a projection optical system that transfers the pattern of the mask onto a substrate. An exposure apparatus comprising the optical device according to claim 1. 10. A method of manufacturing a device including a lithography step, wherein the exposure apparatus according to claim 9 is used to manufacture the device in the lithography step.