JP2006128192A - Holding apparatus, barrel, exposure apparatus, and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the holding apparatus of an optical element for maintaining air-tightness of the internal space of the barrel and also for maintaining the focusing performance of an optical element. <P>SOLUTION: The holding apparatus 1 holds an optical element 2F allocated at the boundary between the internal space K1 of the barrel and an external space K2 different from the internal space K1. Moreover, there are also provided with a first frame member 41 for supporting the circumferential edge 38 of the optical element 2F; a second frame member 42 mounted to the first frame member 41 to include an opposing surface 43 opposing to an internal circumferential surface 39 at the internal side from the circumferential edge 38 among the surface of the optical element 2F; and a first sealing member 30 allocated between the internal circumferential surface 39 and the opposing surface 43 under the condition that it is in contact with the opposing surface 43, but is not in contact with the internal circumferential surface 39 in order to control flow of the air between the internal space K1 and external space K2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a holding device that holds an optical element, a lens barrel, an exposure apparatus, and a device manufacturing method.

Semiconductor devices and liquid crystal display devices are manufactured by a so-called photolithography technique in which a pattern formed on a mask is transferred onto a photosensitive substrate. An exposure apparatus used in this photolithography process has a mask stage for supporting a mask and a substrate stage for supporting a substrate, and a mask pattern is transferred via a projection optical system while sequentially moving the mask stage and the substrate stage. It is transferred to the substrate. The projection optical system includes a plurality of optical elements, and these optical elements are held by a holding device including a lens barrel. Patent Document 1 below discloses an example of a technique related to a holding device that holds an optical element. The holding device disclosed in Patent Document 1 holds an optical element in a kinematic manner, and can hold the optical element without causing distortion in the optical element even when the optical element is thermally expanded, for example. This is effective because the imaging performance can be maintained.
JP 2002-162549 A

  However, the above prior art has the following problems. For example, when vacuum ultraviolet light is used as exposure light, it has a strong absorption characteristic for light in such a wavelength region such as oxygen molecules, water molecules, carbon dioxide molecules, and organic matter in the optical path space that is the space through which the exposure light passes. If a light-absorbing material is present, the exposure light is absorbed by the light-absorbing material and cannot reach the substrate with sufficient light intensity. Therefore, a configuration is conceivable in which the interior space of the lens barrel, which is the optical path space through which the exposure light EL passes, is filled with a predetermined gas (specifically, an inert gas). However, in the holding device disclosed in Patent Document 1, since the gap is formed between the optical element and the holding portion, the airtightness of the internal space of the lens barrel is not maintained. Therefore, even if it is intended to replace the internal space of the lens barrel with a predetermined gas, the gas flows between the internal space of the lens barrel and the external space through the gap, and the internal space of the lens barrel is filled with the predetermined gas. Inconvenience that cannot be done. Then, the exposure light is absorbed by the light-absorbing substance and cannot reach the substrate with sufficient light intensity, leading to deterioration in exposure accuracy.

  The present invention has been made in view of such circumstances, and provides an optical element holding device and a lens barrel that can maintain the airtightness of the internal space of the lens barrel and maintain the imaging performance of the optical element. For the purpose. It is another object of the present invention to provide an exposure apparatus that can satisfactorily expose a substrate using such a holding apparatus and a projection optical system having an optical element held in a lens barrel, and a device manufacturing method using the exposure apparatus. To do.

  In order to solve the above-described problems, the present invention adopts the following configuration corresponding to FIGS. 1 to 11 shown in the embodiment. However, the reference numerals with parentheses attached to each element are merely examples of the element and do not limit each element.

  According to the first aspect of the present invention, the holding for holding the optical element (2F) arranged at the boundary between the first space (K1) and the second space (K2) different from the first space (K1). It is an apparatus, Comprising: The 1st frame member (41) which supports the peripheral part (38) of an optical element (2F), and it attaches to a 1st frame member (41), Out of the surface of an optical element (2F), a periphery A second frame member (42) having a facing surface (43) facing the inner peripheral surface (39) inside the portion (38), and between the first space (K1) and the second space (K2) In order to suppress the flow of gas, it is disposed between the inner peripheral surface (39) and the opposing surface (43) in contact with the opposing surface (43) and in a non-contact state with respect to the inner peripheral surface (39). A holding device (1) comprising a first seal member (30) is provided.

  According to the first aspect of the present invention, the first seal member suppresses the gas flow between the first space and the second space, so that airtightness can be maintained. Further, since the first seal member is disposed in a non-contact state with respect to the inner peripheral surface of the optical element, the optical element is satisfactorily held without receiving a force from the first seal member.

  According to the second aspect of the present invention, in the lens barrel that holds the plurality of optical elements (2A to 2F), the inner space (K1) of the lens barrel (PK) among the plurality of optical elements (2A to 2F). A lens barrel (PK) is provided that holds the optical element (2F) disposed between the lens and the external space (K2) of the lens barrel (PK) with the holding device (1) of the above aspect.

  According to the second aspect of the present invention, the airtightness of the internal space of the lens barrel can be maintained by the first seal member. Therefore, the internal space of the lens barrel can be satisfactorily replaced with the predetermined gas.

  According to the third aspect of the present invention, in the exposure apparatus that exposes the substrate (P) through the projection optical system (PL), the projection optical system (PL) includes a plurality of optical elements (2A to 2F). Among the plurality of optical elements (2A to 2F), an exposure apparatus (1F) that holds the optical element (2F) arranged closest to the image plane side of the projection optical system (PL) with the holding apparatus (1) of the above aspect. EX1, EX2) are provided.

  According to the third aspect of the present invention, since the optical element disposed on the most image plane side of the projection optical system is not distorted, the imaging performance of the projection optical system is maintained and the mirror is maintained. The substrate can be satisfactorily exposed in a state in which the airtightness of the internal space of the cylinder is well maintained.

  According to the fourth aspect of the present invention, a device manufacturing method using the exposure apparatus (EX1, EX2) of the above aspect is provided.

  According to the fourth aspect of the present invention, since the substrate can be exposed with high accuracy, a device having desired performance can be manufactured.

  According to the present invention, since the airtightness of the internal space of the lens barrel can be maintained and the imaging performance of the optical element can be maintained, the substrate can be exposed using a projection optical system having good imaging characteristics. . Thereby, the device which has desired performance can be manufactured.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.

<First Embodiment>
FIG. 1 is a schematic block diagram that shows the first embodiment of the exposure apparatus. In FIG. 1, an exposure apparatus EX1 includes a mask stage MST that supports a mask M, a substrate stage PST that supports a substrate P, and an illumination optical system IL that illuminates the mask M supported by the mask stage MST with exposure light EL. A projection optical system PL that projects and exposes the pattern image of the mask M illuminated by the exposure light EL onto the substrate P supported by the substrate stage PST, and a control device CONT that controls the overall operation of the exposure apparatus EX1. I have.

  In the present embodiment, the exposure apparatus EX1 is a scanning exposure apparatus that exposes the pattern formed on the mask M to the substrate P while moving the mask M and the substrate P in synchronization with each other, for example, in different directions (reverse directions). The case where a so-called scanning stepper) is used will be described as an example. In the following description, the direction that coincides with the optical axis AX of the projection optical system PL is the Z-axis direction, the synchronous movement direction (scanning direction) between the mask M and the substrate P in the plane perpendicular to the Z-axis direction is the X-axis direction, A direction (non-scanning direction) perpendicular to the Z-axis direction and the X-axis direction is defined as a Y-axis direction. Further, the rotation (inclination) directions around the X axis, Y axis, and Z axis are the θX, θY, and θZ directions, respectively.

The illumination optical system IL illuminates the mask M supported by the mask stage MST with the exposure light EL, and the exposure light source, and an optical integrator and an optical integrator for uniformizing the illuminance of the light beam emitted from the exposure light source A condenser lens that collects the exposure light EL from the light source, a relay lens system, a variable field stop that sets the illumination area on the mask M by the exposure light EL in a slit shape, and the like. A predetermined illumination area on the mask M is illuminated with the exposure light EL having a uniform illuminance distribution by the illumination optical system IL. As the exposure light EL emitted from the illumination optical system IL, for example, far ultraviolet light (g-line, h-line, i-line) and KrF excimer laser light (wavelength 248 nm) emitted from a mercury lamp, DUV light), vacuum ultraviolet light (VUV light) such as ArF excimer laser light (wavelength 193 nm) and F ₂ laser light (wavelength 157 nm), or the like is used. In this embodiment, ArF excimer laser light is used.

  The mask stage MST is movable while holding the mask M. For example, the mask M is fixed by vacuum suction (or electrostatic suction). The mask stage MST can be moved two-dimensionally in the plane perpendicular to the optical axis AX of the projection optical system PL, that is, the XY plane, and can be slightly rotated in the θZ direction by a mask stage driving device MSTD including a linear motor or the like. The mask stage MST is movable at a scanning speed specified in the X-axis direction, and the movement stroke in the X-axis direction is such that the entire surface of the mask M can cross at least the optical axis AX of the projection optical system PL. have.

  A movable mirror 4 is provided on the mask stage MST. A laser interferometer 5 is provided at a position facing the movable mirror 4. The position of the mask M on the mask stage MST in the two-dimensional direction and the rotation angle in the θZ direction (including rotation angles in the θX and θY directions in some cases) are measured in real time by the laser interferometer 5, and the measurement result is a control device. Output to CONT. The control device CONT controls the position of the mask M supported by the mask stage MST by driving the mask stage drive device MSTD based on the measurement result of the laser interferometer 5.

  The projection optical system PL projects and exposes the pattern of the mask M onto the substrate P at a predetermined projection magnification β, and is composed of a plurality of optical elements 2 (2A to 2F), and these optical elements 2A to 2F. Is supported by a lens barrel PK. In the present embodiment, the projection optical system PL is a reduction system having a projection magnification β of, for example, 1/4 or 1/5. Note that the projection optical system PL may be either an equal magnification system or an enlargement system.

  The lens barrel PK has a configuration in which a plurality of lens barrel modules (divided lens barrels) SB are combined, and the plurality of optical elements 2A to 2F are held inside these lens barrel modules SB. In particular, among the plurality of optical elements 2A to 2F, the optical element 2F disposed on the most image plane side (−Z side) of the projection optical system PL is the lowermost (−Z side) among the plurality of lens barrel modules SB. Is held by a holding device 1 including a lens barrel module SB provided in the. The optical element 2F held by the holding device 1 is disposed at the boundary between the internal space K1 and the external space K2 of the lens barrel PK.

  The optical element 2F of the projection optical system PL of the present embodiment is disposed at a position close to the image plane of the projection optical system PL next to the optical element 2F among the plurality of optical elements 2A to 2F and the lower surface 2s facing the substrate P. And an upper surface 2t facing the optical element 2E. Each of the upper surface 2t and the lower surface 2s is a flat surface. The upper surface 2t and the lower surface 2s of the optical element 2F are parallel to each other. The upper surface 2t and the lower surface 2s are substantially parallel to the XY plane. That is, the optical element 2F is a non-refractive optical element that is a plane parallel plate and has no lens action.

  The internal space K1 of the lens barrel PK of the projection optical system PL is substantially sealed, and is maintained in a predetermined gas environment by the gas replacement device 3. The gas replacement device 3 supplies a predetermined gas to the inner space K1 of the lens barrel PK via the pipe 3A and collects the gas in the inner space K1 of the lens barrel PK via the pipe 3B. The internal space K1 is maintained in a predetermined gas environment. In the present embodiment, the internal space K1 of the lens barrel PK is filled with an inert gas such as helium, argon, or nitrogen. When the exposure light EL is vacuum ultraviolet light, a substance having strong absorption characteristics with respect to light in such a wavelength region, such as oxygen molecules, water molecules, carbon dioxide molecules, organic matter, etc. in the optical path space through which the exposure light EL passes. If the light-absorbing material is present, the exposure light EL is absorbed by the light-absorbing material and cannot reach the substrate P with sufficient light intensity. However, the inner space K1 of the lens barrel PK, which is the optical path space through which the exposure light EL passes, is substantially sealed to block inflow of light-absorbing substances from the outside, and the inner space K1 of the lens barrel PK is filled with an inert gas. Thus, the exposure light EL can reach the substrate P with sufficient light intensity. The gas replacement device 3 may supply dry air in addition to the inert gas.

  The substrate stage PST is movable while holding the substrate P, and includes an XY stage 9 and a Z tilt stage 8 mounted on the XY stage 9. The XY stage 9 is supported in a non-contact manner above the upper surface of the stage base SB via a gas bearing (air bearing) which is a non-contact bearing (not shown). The XY stage 9 (substrate stage PST) is supported in a non-contact manner with respect to the upper surface of the stage base SB, and is in a plane perpendicular to the optical axis AX of the projection optical system PL by the substrate stage driving device PSTD including a linear motor and the like. That is, it can move two-dimensionally in the XY plane and can rotate in the θZ direction. A Z tilt stage 8 is mounted on the XY stage 9, and the substrate P is held on the Z tilt stage 8 via a substrate holder (not shown) by, for example, vacuum suction. The Z tilt stage 8 is movably provided in the Z-axis direction, the θX direction, and the θY direction. The substrate stage driving device PSTD is controlled by the control device CONT.

  A movable mirror 6 is provided on the substrate stage PST (Z tilt stage 8). A laser interferometer 7 is provided at a position facing the moving mirror 6. The two-dimensional direction position and rotation angle of the substrate P on the substrate stage PST are measured in real time by the laser interferometer 7, and the measurement result is output to the control device CONT. The controller CONT positions the substrate P supported by the substrate stage PST by driving the substrate stage driving device PSTD including a linear motor or the like based on the measurement result of the laser interferometer 7.

  In addition, the exposure apparatus EX1 includes a focus / leveling detection system (not shown) that detects the position of the surface of the substrate P supported by the substrate stage PST. As the configuration of the focus / leveling detection system, for example, the one disclosed in JP-A-8-37149 can be used. The detection result of the focus / leveling detection system is output to the control device CONT. The control device CONT can detect the position information of the surface of the substrate P in the Z-axis direction and the tilt information of the substrate P in the θX and θY directions based on the detection result of the focus / leveling detection system. The Z tilt stage 8 controls the focus position and the tilt angle of the substrate P to adjust the surface of the substrate P to the image plane of the projection optical system PL by the auto focus method and the auto leveling method. Positioning is performed in the axial direction and the Y-axis direction. Needless to say, the Z tilt stage and the XY stage may be provided integrally.

  Next, the holding device 1 will be described with reference to FIG. FIG. 2 is a cross-sectional view showing the holding device 1 in a state where the optical element 2F is held.

  As described above, the optical element 2F arranged on the most image plane side of the projection optical system PL is a parallel plane plate having a flat upper surface 2t and a lower surface 2s. The outer diameter of the upper surface 2t is larger than the outer diameter of the lower surface 2s, and a flange portion 38A is formed on the peripheral portion 38 of the optical element 2F. Furthermore, a ring-shaped inner peripheral surface 39 facing the lower side (−Z side) is formed on the inner side of the peripheral portion 38 in the surface of the optical element 2F. The inner peripheral surface 39 is substantially parallel to the XY plane.

  The holding device 1 is provided so as to surround the peripheral portion 38 of the optical element 2F, is attached to the first frame member 41 that supports the peripheral portion 38, and the inner peripheral surface 39 of the optical element 2F. The second frame member 42 having a facing surface 43 facing the first frame member 42, and the first seal member 30 disposed between the facing surface 43 of the second frame member 42 and the inner peripheral surface 39 of the optical element 2F. . As described above, the holding device 1 is configured to include the ring-shaped lens barrel module SB provided at the lowermost portion among the plurality of lens barrel modules SB, and the lens barrel module SB includes: A part of the first frame member 41 is configured. The first frame member 41 includes the lens barrel module SB and three holding portions 40 that are arranged on the lens barrel module SB at equal angular intervals and hold the flange portion 38A of the optical element 2F. It has a configuration. The holding unit 40 holds the optical element 2F in a kinematic manner.

  The lens barrel module SB of the first frame member 41 and the second frame member 42 are fixed by screws 42N in a state where the lower surface SBA of the lens barrel module SB and the upper surface 42J of the second frame member 42 are in contact with each other. Has been.

  The first seal member 30 is formed in a ring shape and is supported on the facing surface 43 of the second frame member 42. The second frame member 42 also has a ring shape as a whole, and the facing surface 43 is also formed in a ring shape. The first seal member 30 is made of, for example, stainless steel or brass. The forming material for the first seal member 30 may be a synthetic resin including a rubber material. The upper surface 31 of the first seal member 30 is processed to have very good flatness (surface roughness (arithmetic average roughness Ra) is, for example, about 1 μm).

  The upper surface 31 of the first seal member 30 supported by the second frame member 42 faces the inner peripheral surface 39 of the optical element 2F supported by the first frame member 41 and is substantially parallel to the XY plane. It is a flat surface. Note that the lower surface 32 of the first seal member 30 facing the facing surface 43 of the second frame member 42 is also a surface substantially parallel to the XY plane. Furthermore, the facing surface 43 of the second frame member 42 is also a surface substantially parallel to the XY plane. There is a gap between the upper surface (plane) 31 of the first seal member 30 supported by the second frame member 42 and the inner peripheral surface 39 of the optical element 2F supported by the first frame member 41. (Gap) G1 is provided to have a predetermined value, and the upper surface 31 of the first seal member 30 and the inner peripheral surface 39 of the optical element 2F are not in contact with each other. Further, the inner peripheral surface 42A of the second frame member 42 and the outer peripheral surface 30A of the first seal member 30 are in contact with each other. However, the inner peripheral surface 42A and the outer peripheral surface 30A do not necessarily have to be in contact with each other.

  A spacer member 33 is disposed between the lower surface 32 of the first seal member 30 and the facing surface 43 of the second frame member 42. The spacer member 33 has a function as an adjustment mechanism that adjusts the gap G1 between the inner peripheral surface 39 of the optical element 2F and the upper surface 31 of the first seal member 30. In the present embodiment, the spacer member 33 is constituted by a washer member. The spacer members 33 are arranged on the facing surface 43 at predetermined angular intervals. The gap G1 can be adjusted by appropriately changing the thickness of the spacer member 33 to be used or by appropriately changing the number of stacked spacer members 33. Then, in a state where the spacer member 33 is disposed between the lower surface 32 of the first seal member 30 and the facing surface 43 of the second frame member 42, the first seal member 30 and the second frame member 42 are screwed to 33N. It is fixed by.

  The upper surface of the spacer member 33 is also a facing surface facing the inner peripheral surface 39 of the optical element 2F, and the lower surface 32 of the first seal member 30 is supported by the upper surface of the spacer member 33. The second frame member 42 supports the first seal member 30 through the spacer member 33 so as to form a predetermined gap G1.

  In the present embodiment, the gap G1 is set to about 1 μm to 20 μm, preferably about 10 μm. In this way, by setting the gap G1 to a predetermined value, the flow of gas through the gap G1 between the internal space K1 and the external space K2 of the lens barrel PK is suppressed, and the internal space K1 of the lens barrel PK. Airtightness is ensured.

  In the present embodiment, since the spacer member 33 is disposed between the first seal member 31 and the second frame member 42, the lower surface 32 of the first seal member 30 and the second frame member 42 are disposed. A gap (gap) G <b> 2 is also formed between the opposite surface 43. Therefore, a second seal member 34 made of, for example, an O-ring is disposed between the first seal member 30 and the facing surface 43 of the second frame member 42. Specifically, a recess 43A is formed in a part of the facing surface 43 of the second frame member 42, and the position of the second seal member 34 is fixed by being disposed in the recess 43A. As described above, since the inner peripheral surface 42A of the second frame member 42 and the outer peripheral surface 30A of the first seal member 30 are in contact, the inner peripheral surface 42A of the second frame member 42 and the first seal member Between the 30 outer peripheral surfaces 30A, the circulation of gas is suppressed. Thus, by providing the second seal member 34, the gas flow between the internal space K1 of the lens barrel PK and the external space K2 through the gap G2 is suppressed, and the internal space K1 of the lens barrel PK. Airtightness is ensured. Even if there is a gap between the inner peripheral surface 42A and the outer peripheral surface 30A, if there is the second seal member 34, the gas flow through the gap G2 is suppressed.

  Hereinafter, an adjustment procedure for setting the gap G1 to a desired value will be described with reference to FIGS.

  First, as shown in FIG. 3A, the optical element 2F is held by the first frame member 41 (step 1). The optical element used here may be the optical element 2F actually mounted on the projection optical system PL, or a dummy optical element similar to the optical element 2F. Moreover, although not shown in FIG. 3, the optical element 2F is held by a holding unit 40 described later. Next, as shown in FIG. 3B, the first frame member 41 holding the optical element 2F is placed on the adjustment surface plate so that the upper surface 2t of the optical element 2F and the reference surface F of the adjustment surface plate face each other. Place on top. Then, the measuring instrument 100 measures the position (height) of the lower surface SBA of the first frame member 41 (lens barrel module SB) with respect to the reference surface F and the position (height) of the inner peripheral surface 39 of the optical element 2F with respect to the reference surface F. Use to measure. Thereby, the positional relationship (height difference) between the lower surface SBA of the first frame member 41 and the inner peripheral surface 39 of the optical element 2F with reference to the reference surface F can be obtained (step 2). Next, as shown in FIG. 3C, the second frame member 42 is placed on the adjustment surface plate, and the position (height) of the upper surface 42J of the second frame member 42 with respect to the reference plane F, and the second The position (height) of the facing surface 43 of the two-frame member 42 with respect to the reference surface F is measured using the measuring instrument 100. Thereby, the positional relationship (height difference) between the upper surface 42J of the second frame member 42 and the opposing surface 43 with the reference surface F as a reference can be obtained (step 3).

  Next, as shown in FIG. 4A, the first seal member 30 is placed on the adjustment surface plate, and the position (height) of the upper surface 31 of the first seal member 30 with respect to the reference plane F is measured by a measuring instrument. Measurement is performed using 100 (step 4). Based on the measurement results of Step 2 and Step 3 above, the reference plane F when the first frame member 41 and the second frame member 42 are connected and the optical element 2F is held by the first frame member 41 is used as a reference. The positional relationship between the inner peripheral surface 39 of the optical element 2F and the opposing surface 43 of the second frame member 42, that is, the distance between the inner peripheral surface 39 and the opposing surface 43 can be obtained. Therefore, the spacer member 33 having an optimum thickness for setting the gap G1 to a desired value is selected (determined) based on the obtained distance between the inner peripheral surface 39 and the facing surface 43 and the measurement result of step 4. can do. Then, as shown in FIG. 4B, the selected (determined) spacer member 33 is disposed between the facing surface 43 of the second frame member 42 and the lower surface 32 of the first seal member 30 (step S5). ).

  Next, as shown in FIG. 4C, it is tested using the test apparatus 105 whether or not the gas flow is suppressed in the gap G1 (step 6). 4C includes a cover member 101 that is connected to the first frame member 41 and forms an internal space K1 between the optical element 2F and the first frame member 41. A gas (for example, nitrogen gas) is supplied to the formed internal space K <b> 1 through the supply pipe 102. On the other hand, the gas in the internal space K <b> 1 is discharged to the outside through the discharge pipe 103. A first sensor 102A that measures a gas flow rate (or pressure) per unit time flowing through the supply pipe 102 is provided in the middle of the supply pipe 102, and per unit time that flows through the discharge pipe 103 in the middle of the discharge pipe 103. A second sensor 103A for measuring the gas flow rate (or pressure) is provided. When the gas flow is suppressed in the gap G1, the measurement result of the first sensor 102A and the measurement result of the second sensor 103A are substantially equal. On the other hand, when a gas flow occurs in the gap G1, there is a difference between the measurement result of the first sensor 102A and the measurement result of the second sensor 103A. Based on the measurement results of the first and second sensors 102A and 103A, the test apparatus 105 can determine whether or not the gas flow is suppressed in the gap G1. If it is determined that gas is flowing between the internal space K1 and the external space K2 via the gap G1, the gap G1 is readjusted, for example, by replacing with another spacer member 33. Good.

  The spacer member 33 may be a ring-shaped member formed so as to correspond to the lower surface 32 of the first seal member 30, or is processed to have a surface roughness equivalent to that of the first seal member 30, It may be a ring-shaped member that functions as: In that case, the second seal member 34 made of an O-ring as shown in FIG. 2 can be omitted.

  Alternatively, if the gap G1 between the inner peripheral surface 39 of the optical element 2F and the upper surface 31 of the first seal member 30 can be set to a desired value, the first seal member is not provided without providing the spacer member 33. 30 may be directly supported so as to contact the facing surface 43 of the second frame member 42. Even in this case, since no gap is formed between the lower surface 32 of the first seal member 30 and the opposing surface 43 of the second frame member 42, the second seal member 34 as shown in FIG. Good.

  As described above, the first frame member 41 has the holding portion 40 that holds the optical element 2F in a kinematic manner. Hereinafter, the holding unit 40 will be described with reference to FIGS. 5 is a perspective view of the holding device 1 viewed from below with the second frame member 42 and the first seal member 30 of FIG. 2 removed, FIG. 6 is a perspective view of the holding portion 40, and FIG. 7 is a perspective view of the holding portion 40. FIG. 8 is a side sectional view of the holding unit 40 as viewed from below. Here, as described above, three holding portions 40 are arranged on the lens barrel module SB at equal angular intervals, and each of the three holding portions 40 has an equivalent configuration. In the following description, an XYZ rectangular coordinate system is set, and one holding unit 40 among the three holding units 40 will be described with reference to the XYZ rectangular coordinate system. 6-8, the radial direction of the optical element 2F is the X-axis direction, the tangential direction of the optical element 2F is the Y-axis direction, and the direction parallel to the optical axis (AX) of the optical element 2F is used. The description will be made on the Z-axis direction.

  The holding unit 40 includes a base member 45 and a clamp member 46. A mounting groove 44 for arranging the clamp member 46 is formed on the lower surface of the lens barrel module SB. As described above, the holding portions 40 are arranged at equal angular intervals on the lens barrel module SB, and the mounting grooves 44 are formed at equal angular intervals on the lower surface of the lens barrel module SB. Yes. Furthermore, a housing recess 60 for housing the seat block 50A of the base member 45 is formed on the inner peripheral surface of the lens barrel module SB. The housing recess 60 is formed at a position corresponding to the mounting groove 44. The base member 45 is fixed to the upper surface of the lens barrel module SB opposite to the lower surface where the mounting groove 44 is formed by a pair of bolts.

  The base member 45 forms a seating surface block 50A having a seating surface 49 that contacts the upper surface of the flange portion 38A of the optical element 2F, and a seating surface block support mechanism 51 that supports the posture of the seating surface block 50A in an adjustable manner. Support block 50B.

  The seating surface block 50A is arranged so that its longitudinal direction coincides with the Y-axis direction. The seating surface 49 is formed at each of both ends in the longitudinal direction of the seating surface block 50A so as to protrude downward from the surface (lower surface) of the seating surface block 50A.

  A plurality of slits 53 penetrating in the X-axis direction are formed between the seating block 50A and the support block 50B and in the support block 50B. When the plurality of slits 53 are formed, a portion that is not processed is left between the slits 53 so that all the slits 53 are not continuous with each other. And the process which engraves from the + X direction with respect to the part which does not give this process, and the process which engraves from -X direction are given, and the engraved part 54 is formed. By the engraving process from each of the + X direction and the −X direction, a plurality of first to fourth neck portions 55A to 55D are formed between the seating block 50A and the support block 50B and in the support block 50B. .

  Here, the support block 50 </ b> B is roughly divided into three parts by a plurality of slits 53. That is, the support block 50B is divided into a base portion 56 fixed to the lens barrel module SB, a first block 57A, and a second block 58A. Furthermore, a first neck portion 55A for connecting the base portion 56 and the first block 57A, a second neck portion 55B for connecting the base portion 56 and the second block 58A, a first block 57A and a second block 58A, The third neck portion 55C for connecting the second block 58A and the fourth neck portion 55D for connecting the second block 58A and the seating surface block 50A are formed. Each of the plurality of neck portions 55A to 55D is square in cross section, and has a cross-sectional area that is significantly smaller than the cross-sectional areas of the first block 57A, the second block 58A, the base portion 56, and the seating surface block 50A. ing.

  The first block 57A is fixed to the base portion 56 and the second block 58A by the first neck portion 55A and the third neck portion 55C. The first block 57A is rotatably held in the θY direction by the first neck portion 55A and the third neck portion 55C, but the displacement in the Y-axis direction is restricted. That is, the first block 57A, the first neck portion 55A, and the third neck portion 55C form a tangential restriction link 57 that restricts displacement of the optical element 2F in the tangential direction (Y-axis direction).

  The second block 58A is fixed to the base portion 56 and the seat block 50A by the second neck portion 55B and the fourth neck portion 55D. The second block 58A is rotatably held in the θZ direction by the second neck portion 55B and the fourth neck portion 55D, but the displacement in the Z-axis direction is restricted. That is, the second block 58A, the second neck portion 55B, and the fourth neck portion 55D form an optical axis direction restraint link 58 that restrains displacement in the direction parallel to the optical axis of the optical element 2F (Z axis direction). Yes.

  The restraining direction of the tangential direction restraining link 57 and the restraining direction of the optical axis direction restraining link 58 are substantially orthogonal to each other. In other words, the rotation axis of the tangential direction restriction link 57 and the rotation axis of the optical axis direction restriction link 58 are substantially orthogonal to each other.

  The seat block 50A is connected to the support block 50B by the fourth neck 55D.

  Of the first to fourth neck portions 55A to 55D, the second neck portion 55B and the fourth neck portion 55D are arranged on a line passing through an intermediate position of the seating surface 49 of the seating surface block 50B. The line is orthogonal to the line connecting the pair of seating surfaces 49 and is parallel to the Z-axis direction. On the other hand, the first neck portion 55 </ b> A and the third neck portion 55 </ b> C are disposed on a line parallel to a line connecting the pair of seating surfaces 49. Further, the third neck portion 55C is disposed in the vicinity of the fourth neck portion 55D.

  In the base member 45 configured as described above, the seat block 50A is moved in the θX direction, the θY direction, and the θZ direction with respect to the base portion 56 by the tangential direction restriction link 57 and the optical axis direction restriction link 58. It is supported so that the displacement in the Y-axis direction and the Z-axis direction is suppressed. Further, the seat block 50A is supported by the fourth neck portion 55D so as to be displaceable in the X-axis direction. That is, the seat block support mechanism 51 includes a tangential direction restraint link 57, an optical axis direction restraint link 58, and a fourth neck portion 55D that can be displaced in the X-axis direction.

  In addition, a seating surface side mounting portion 59 extending in the −Z direction (that is, the thickness direction of the flange portion 38A of the optical element 2F) with respect to the seating surface 49 is formed in the seating surface block 50A. In other words, the seating surface side attachment portion 59 is provided at a position lower than the seating surface 49.

  The clamp member 46 includes a clamp body 62 and a pad member 47, and is disposed corresponding to the lower side of the seating surface block 50A.

  The clamp body 62 includes a pressing surface block 63 and a pressing surface block support mechanism 64 that is formed integrally with the pressing surface block 63 and supports the pressing surface block 63. At both ends of the upper surface of the pressing surface block 63, pressing surfaces 65 are formed so as to face the seating surface 49 of the seating surface block 50A. The pressing surface 65 is formed in a triangular cross section having a ridge line along the Y-axis direction. The ridge line of both pressing surfaces 65 is formed so that the midpoint of the straight line connecting the two ridge lines is located above the fourth neck portion 55d that connects the seat surface block 50A and the optical axis direction restraint link 58. Yes.

  The pressing surface block support mechanism 64 includes an arm portion 66 and a pressing surface side mounting portion 67. The pressing surface side mounting portion 67 and the pressing surface block 63 are separated from each other with a predetermined interval. Then, the clamp member 62 is fastened with the bolt 68 in a state where the pressing surface side mounting portion 67 of the clamp body 62 and the seating surface side mounting portion 59 of the seating surface block 50A are joined via the pad member 47. 46 is fixed to the seating block 50A. A pair of arm portions 66 are provided so as to connect both ends of the pressing surface block 63 and the pressing surface side mounting portion 67. The arm portion 66 is formed with a length that can be elastically deformed in a state where the pressing surface side mounting portion 67 and the seating surface side mounting portion 59 are joined via the pad member 47.

  The pad member 47 includes a sandwiching portion 71 disposed between the seating surface side mounting portion 59 and the pressing surface side mounting portion 67, and an action portion disposed between the pressing surface 65 and the flange portion 38A of the optical element 2F. 72, and a thin plate portion 73 that connects the sandwiching portion 71 and the action portion 72 and is elastically deformable. On the upper surface of the action portion 72, an action surface 74 that abuts against the lower surface of the flange portion 38A of the optical element 2F is formed. The action surface 74 is formed in a flat shape so as to correspond to the seating surface 49. The working surface 74 has a configuration similar to that of the seating surface 49, and the periphery thereof is formed in a curved surface shape having a predetermined curvature.

  When the bolt 68 is tightened in a state where the flange portion 38A of the optical element 2F is disposed between the seat surface 49 of the base member 45 and the working surface 74 of the clamp member 46, the arm portion 66 is elastically deformed, A pressing force toward the seat surface block 50 </ b> A is applied to the pressing surface 65 of the pressing surface block 63. This pressing force acts on the flange portion 38A of the optical element 2F via the action surface 74 of the pad member 47. Accordingly, the flange portion 38A of the optical element 2F is held between the seating surface 49 of the seating surface block 50A and the working surface 74 of the pad member 47.

  In the configuration described above, the optical element 2F and the lens barrel module SB are formed of different materials, and there may be a difference in linear expansion coefficient between the optical element 2F and the lens barrel module SB. For this reason, when the optical element 2F or the like generates heat due to the exposure light EL irradiation, there is a difference in expansion / contraction length in the radial direction of the optical element 2F between the optical element 2F and the lens barrel module SB. is there. When such a difference in expansion / contraction length occurs, the seating surface that holds the optical element 2F by the cooperative action of the restraining links 57 and 58 of the seating surface block support mechanism 51 and the neck portions 55A to 55A. The block 50A and the pressing surface block 63 are relatively moved in the radial direction of the optical element 2F with respect to the lens barrel module SB. Thereby, the difference in the expansion / contraction length is absorbed, and there is no possibility that a large expansion / contraction load is directly applied to the optical element 2F.

  Further, when stacking the lens barrel module SB, there is a risk that slight distortion will occur in the lens barrel module SB. Even if the lens barrel module SB is distorted in this way, the optical element 2F can be moved into the lens barrel module SB by the cooperative action of the restraining links 57 and 58 and the neck portions 55A to 55D of the seat block support mechanisms 51. Therefore, the distortion is prevented from affecting the optical element 2F.

  For example, when thermal deformation occurs in the optical element 2F, the optical element 2F expands or contracts in the radial direction. When such expansion or contraction occurs, the fourth neck portion 55D is connected to the diameter of the optical element 2F. Force acts in the direction to be displaced in the direction. In response to this force, each of the restraining links 57 and 58 is rotated with the line connecting the first neck portion 55A and the second neck portion 55B forming the connection point with the lens barrel module SB as an axis, and the optical element 2F is rotated by the rotational movement. The displacement of the peripheral edge of the optical element 2F due to the thermal deformation of is absorbed. Thereby, it is suppressed that distortion arises in optical element 2F.

  As described above, the first frame member 41 is configured to hold the optical element 2F in a kinematic manner, and thus can hold the optical element 2F without causing distortion in the optical element 2F. In addition, since the first seal member 30 suppresses the gas flow between the internal space K1 and the external space K2 of the lens barrel PK, the airtightness of the internal space K1 of the lens barrel PK can be maintained. Therefore, it is possible to satisfactorily replace the internal space K1 of the lens barrel PK with the predetermined gas using the gas replacement device 3. Accordingly, even when vacuum ultraviolet light is used as the exposure light EL, the airtightness of the internal space K1 of the lens barrel PK, which is the optical path space through which the exposure light EL passes, is maintained, and the inflow of the light-absorbing substance from the external space K2 And the inner space K1 of the lens barrel PK can be filled with an inert gas, and the exposure light EL can reach the substrate P with sufficient light intensity. In this way, the optical element 2F is not distorted, the exposure light EL can reach the substrate P with sufficient light intensity, and the substrate P is maintained in a state in which the good imaging performance of the projection optical system PL is maintained. Can be exposed. Since the first seal member 30 is disposed in a non-contact state with respect to the inner peripheral surface 39 of the optical element 2F, the optical element 2F does not receive a force directly from the first seal member 30. Therefore, the deformation and displacement of the optical element 2F can be prevented and the substrate P can be exposed satisfactorily.

  In the present embodiment, the optical element 2F is a plane parallel plate, but may not be a plane parallel plate. For example, at least one of the upper surface 2t and the lower surface 2s of the optical element 2F may have a curvature.

<Second Embodiment>
Next, a second embodiment of the exposure apparatus will be described with reference to FIG. In the following description, the same reference numerals are given to the same or equivalent components as those in the first embodiment described above, and the description thereof is simplified or omitted.

  An exposure apparatus EX2 according to the second embodiment is an immersion exposure apparatus to which an immersion method is applied in order to improve the resolution by substantially shortening the exposure wavelength and substantially increase the depth of focus. An immersion mechanism 150 that fills the liquid LQ is provided between the optical system PL and the substrate P. The liquid immersion mechanism 150 is a nozzle that is provided above the substrate P (substrate stage PST) and is an annular member that is provided so as to surround the side surface of the optical element 2F disposed closest to the image plane in the projection optical system PL. The member 70, the liquid supply mechanism 10 that supplies the liquid LQ onto the substrate P through the liquid supply port 12 provided in the nozzle member 70, and the substrate P through the liquid recovery port 22 provided in the nozzle member 70. And a liquid recovery mechanism 20 for recovering the liquid LQ.

  The liquid supply mechanism 10 includes a liquid supply unit 11 that can deliver the liquid LQ, and a supply pipe 13 that connects one end of the liquid supply unit 11 to the liquid supply unit 11. The other end of the supply pipe 13 is connected to the nozzle member 70. The liquid supply unit 11 includes a tank that stores the liquid LQ, a pressure pump, a filter unit, and the like. The liquid recovery mechanism 20 is for recovering the liquid LQ on the image plane side of the projection optical system PL. The liquid recovery unit 21 can recover the liquid LQ, and one end of the liquid recovery unit 21 is connected to the liquid recovery unit 21. And a recovery pipe 23 to be connected. The other end of the recovery pipe 23 is connected to the nozzle member 70. The liquid recovery unit 21 includes, for example, a vacuum system (a suction device) such as a vacuum pump, a gas-liquid separator that separates the recovered liquid LQ and gas, and a tank that stores the recovered liquid LQ.

  The nozzle member 70 is provided above the substrate P (substrate stage PST), and the lower surface 70A of the nozzle member 70 faces the surface of the substrate P. The liquid supply port 12 is provided on the lower surface 70A of the nozzle member 70A. In addition, an internal flow path that connects the supply pipe 13 and the liquid supply port 12 is provided inside the nozzle member 70. The liquid recovery port 22 is also provided on the lower surface 70A of the nozzle member 70, and is provided outside the liquid supply port 12 with respect to the optical axis AX of the projection optical system PL (optical element 2F). In addition, an internal flow path that connects the recovery pipe 23 and the liquid recovery port 22 is provided inside the nozzle member 70.

  The operation of the liquid supply unit 11 is controlled by the control device CONT. When supplying the liquid LQ onto the substrate P, the control device CONT sends the liquid LQ from the liquid supply unit 11 and is provided above the substrate P via the supply pipe 13 and the internal flow path of the nozzle member 70. The liquid LQ is supplied onto the substrate P from the liquid supply port 12. The liquid recovery operation of the liquid recovery unit 21 is controlled by the control device CONT. The control device CONT can control the liquid recovery amount per unit time by the liquid recovery unit 21. The liquid LQ on the substrate P recovered from the liquid recovery port 22 provided above the substrate P is recovered by the liquid recovery part 21 via the internal flow path of the nozzle member 70 and the recovery pipe 23.

  While transferring at least the pattern image of the mask M onto the substrate P, the control device CONT projects the projection onto a part of the substrate P including the projection area of the projection optical system PL by the liquid LQ supplied from the liquid supply mechanism 10. A liquid immersion region LR that is larger than the region and smaller than the substrate P is locally formed. Specifically, the exposure apparatus EX2 employs a local immersion method in which the liquid LQ is filled between the optical element 2F disposed on the most image plane side of the projection optical system PL and the surface of the substrate P. The pattern of the mask M is projected and exposed to the substrate P by irradiating the substrate P with the exposure light EL that has passed through the mask M via the liquid LQ between the system PL and the substrate P and the projection optical system PL. Therefore, the liquid LQ in the liquid immersion area LR comes into contact with the optical element 2F.

  Each of the lower surface 2s of the optical element 2F of the projection optical system PL and the lower surface 70A of the nozzle member 70 is a flat surface, and the lower surface 2s of the optical element 2F of the projection optical system PL and the lower surface 70A of the nozzle member 70. Is almost the same. Further, a recess 8A is provided on the substrate stage PST (Z stage 8), and a substrate holder PH for holding the substrate P is disposed in the recess 8A. The upper surface 8S of the Z stage 8 other than the recess 8A is a flat surface that is substantially the same height (level) as the upper surface of the substrate P held by the substrate holder PH. Thereby, the liquid immersion region LR can be satisfactorily formed between the lower surface 70A of the nozzle member 70 and the lower surface 2s of the optical element 2F and the substrate P (substrate stage PST). Further, by providing the upper surface 8S, the liquid immersion region LR can be favorably formed by holding the liquid LQ on the image plane side of the projection optical system PL even when the peripheral edge of the substrate P is subjected to liquid immersion exposure. it can.

  FIG. 10 is a side sectional view of the optical element 2F and the nozzle member 70 provided so as to surround the side surface thereof.

  As shown in FIG. 10, the exposure apparatus EX2 according to the present embodiment performs a liquid LQ between the side surface 2r of the optical element 2F that contacts the liquid LQ in the liquid immersion area LR formed on the substrate P and the nozzle member 70. The third seal member 80 is provided to prevent the intrusion. The third seal member 80 is configured by a so-called V-ring, and is formed in an annular shape so as to surround the optical element 2F. The third seal member 80 has flexibility and liquid repellency. In the present embodiment, the third seal member 80 is made of fluororubber. Fluoro rubber is preferable because it has flexibility and liquid repellency, has little outgas, is insoluble in the liquid LQ, and has little influence on the exposure process. In addition, as the 3rd seal member 80, you may make it coat a liquid repellent material on the surface of the cyclic | annular member formed with the predetermined material which has flexibility. The third seal member 80 includes a main body portion 81 attached to the inner side surface 70T of the nozzle member 70, and a contact portion 83 that is connected to the main body portion 81 via the hinge portion 82 and contacts the side surface 2r of the optical element 2F. ing. The contact portion 83 is a substantially annular (conical) member. Further, a recess 71 capable of holding the main body 81 of the third seal member 80 is formed in the vicinity of the lower end portion of the inner surface 70T of the nozzle member 70. The recess 71 is formed in a substantially annular shape in plan view so as to follow the inner side surface 70 </ b> T of the nozzle member 70. By fitting the main body portion 81 of the third seal member 80 into the recess 71, the main body portion 81 is attached near the lower end portion of the inner side surface 70 </ b> T of the nozzle member 70. Then, in a state where the main body portion 81 of the third seal member 80 is attached to the inner side surface 70T (recessed portion 71) of the nozzle member 70, the contact portion 83 contacts the vicinity of the lower end portion of the side surface 2r of the optical element 2F. The contact portion 83 is thinner than the main body portion 81, and can be largely bent while being in contact with the side surface 2 of the optical element 2F.

  Then, in a state where the main body portion 81 of the third seal member 80 is attached to the inner side surface 70T of the nozzle member 70, the contact portion 83 generates a force in the direction of pushing the side surface 2r of the optical element 2F. Thereby, the contact part 83 and the side surface 2r of the optical element 2F are adhered. This prevents the liquid LQ in the liquid immersion region LR from entering the gap (gap) G3 between the side surface 2r of the optical element 2F and the nozzle member 70. Further, by preventing the liquid LQ from entering the gap G3, it is possible to more reliably prevent the liquid LQ (or wet gas) from entering the internal space K1 of the lens barrel PK.

  Further, since the contact portion 83 has flexibility, even if vibration is generated in the nozzle member 70, for example, the contact portion 83 is absorbed by bending or the hinge portion 82 is elastically deformed. it can. Therefore, it is possible to prevent vibration generated in the nozzle member 70 from being transmitted to the optical element 2F of the projection optical system PL. Moreover, the force which the 3rd seal member 80 (contact part 83) gives to the optical element 2F can be reduced because the contact part 83 bends or the hinge part 82 elastically deforms. Accordingly, it is possible to prevent the occurrence of inconvenience such as the optical element 2F being distorted or displaced.

  Here, the main body portion 81 of the third seal member 80 is attached to the nozzle member 70 and the contact portion 83 is in contact with the optical element 2F. However, the main body portion 81 of the third seal member 80 is connected to the side surface of the optical element 2F. 2r may be attached so that the contact portion 83 is brought into contact with the inner surface 70T of the nozzle member 70.

  Each of the side surface 2r of the optical element 2F forming the gap G3 and the inner side surface 70T of the nozzle member 70 facing the side surface 2r of the optical element 2F are liquid repellent. Specifically, each of the inner side surface 70T and the side surface 2r has liquid repellency by being subjected to a liquid repellency treatment. Examples of the liquid repellency treatment include a process of applying a liquid repellent material such as a fluorine resin material, an acrylic resin material, or a silicon resin material, or applying a thin film made of the liquid repellent material. Since each of the third seal member 80, the side surface 2r of the optical element 2F, and the inner side surface 70T of the nozzle member 70 has liquid repellency, for example, even when the liquid LQ enters the gap G3 by capillary action, The entered liquid LQ is repelled and does not stay in the gap G3.

  Also in the present embodiment, the optical element 2F is held kinematically by the first frame member 41 as in the first embodiment described above. Here, the upper surface 2t of the optical element 2F of the present embodiment is formed in a convex shape toward the object surface side (mask M side, + Z side) as shown in FIG. 10, and has a positive refractive index. is doing. By using such an optical element 2F, it is possible to adjust optical characteristics of the projection optical system PL, for example, aberrations (spherical aberration, coma aberration, etc.). In the projection optical system PL used in the immersion exposure apparatus EX2, the upper surface 2t of the optical element 2F that contacts the liquid LQ in the immersion area LR has a reflection loss of light (exposure light EL) incident on the upper surface 2t. In order to reduce and to secure a large image-side numerical aperture, it may be formed in a convex shape toward the object plane side. However, when the optical element 2F having such a refractive index (lens action) is displaced, there is a possibility that the imaging performance of the projection optical system PL will change significantly. However, even such an optical element 2 </ b> F can be kinematically held by the above-described first frame member 41 to prevent the above-described inconvenience.

  Further, the second frame member 42 of the holding device 1 in the present embodiment includes a cover member 90 formed of a material different from that of the second frame member 42. The cover member 90 is attached to the lower surface 42K of the second frame member 42, is formed in a ring shape, and is provided so as to cover the lower surface 42K of the second frame member 42. In the present embodiment, the second frame member 42 is made of a metal such as stainless steel, and the cover member 90 is made of a fluorine-based resin such as PTFE (polytetrafluoroethylene). When the second frame member 42 is made of metal, there is a possibility that inconvenience such as rusting occurs when the liquid LQ in the liquid immersion region LR adheres. Conversely, eluents such as metal ions enter the liquid LQ in the immersion area LR from the second frame member 42 made of metal, and affect the liquid LQ in the immersion area LR. If the liquid recovery mechanism 20 recovers the contained liquid LQ, there is a possibility that the liquid recovery mechanism 20 may be affected. Therefore, in order to prevent such inconvenience, a cover member 90 is provided on the second frame member 42. In addition, as a material for forming the cover member 90, the influence on the exposure process can be reduced by adopting a fluorine-based resin having advantages such as less outgas and insolubility in the liquid LQ.

  Note that the cover member 90 prevents the second frame member 42 and the liquid LQ in the liquid immersion region LR from affecting each other, so that the attachment position thereof is the lower surface 42K of the second frame member 42. Not limited to this, it may be disposed between the second frame member 42 and the liquid LQ in the liquid immersion region LR. For example, when the outer diameter of the nozzle member 70 is smaller than the outer diameter of the second frame member 42, the cover member 90 may be provided so as to surround the outer surface of the nozzle member 70.

  In the second embodiment described above, pure water is used as the liquid LQ. Pure water has an advantage that it can be easily obtained in large quantities at a semiconductor manufacturing factory or the like, and has no adverse effect on the photoresist, optical element (lens), etc. on the substrate P. In addition, pure water has no adverse effects on the environment, and since the impurity content is extremely low, it can be expected to clean the surface of the substrate P and the surface of the optical element provided on the front end surface of the projection optical system PL. . When the purity of pure water supplied from a factory or the like is low, the exposure apparatus may have an ultrapure water production device.

  The refractive index n of pure water (water) with respect to the exposure light EL having a wavelength of about 193 nm is said to be approximately 1.44. When ArF excimer laser light (wavelength 193 nm) is used as the light source of the exposure light EL, On the substrate P, the wavelength is shortened to 1 / n, that is, about 134 nm, and a high resolution can be obtained. Furthermore, since the depth of focus is enlarged by about n times, that is, about 1.44 times compared with that in the air, the projection optical system PL can be used when it is sufficient to ensure the same depth of focus as that in the air. The numerical aperture can be further increased, and the resolution is improved in this respect as well.

  As described above, when the liquid immersion method is used, the numerical aperture NA of the projection optical system may be 0.9 to 1.3. When the numerical aperture NA of the projection optical system becomes large in this way, the imaging performance may deteriorate due to the polarization effect with random polarized light conventionally used as exposure light. desirable. In that case, linearly polarized illumination is performed in accordance with the longitudinal direction of the line pattern of the mask (reticle) line-and-space pattern. From the mask (reticle) pattern, the S-polarized light component (TE-polarized light component), that is, the line pattern It is preferable that a large amount of diffracted light having a polarization direction component is emitted along the longitudinal direction. When the space between the projection optical system PL and the resist applied on the surface of the substrate P is filled with a liquid, the space between the projection optical system PL and the resist applied on the surface of the substrate P is filled with air (gas). Compared with the case where the transmittance of the diffracted light of the S-polarized component (TE-polarized component) contributing to the improvement of the contrast is high on the resist surface, the numerical aperture NA of the projection optical system exceeds 1.0. Even in this case, high imaging performance can be obtained. Further, it is more effective to appropriately combine a phase shift mask or an oblique incidence illumination method (particularly a die ball illumination method) or the like according to the longitudinal direction of the line pattern as disclosed in JP-A-6-188169. In particular, the combination of the linearly polarized illumination method and the diball illumination method is used when the periodic direction of the line-and-space pattern is limited to a predetermined direction, or when the hole pattern is closely packed along the predetermined direction It is effective when For example, when illuminating a halftone phase shift mask with a transmittance of 6% (a pattern with a half pitch of about 45 nm) using both the linearly polarized illumination method and the dieball illumination method, a dieball is formed on the pupil plane of the illumination system. If the illumination σ defined by the circumscribed circle of the two luminous fluxes is 0.95, the radius of each luminous flux on the pupil plane is 0.125σ, and the numerical aperture of the projection optical system PL is NA = 1.2, the randomly polarized light is The depth of focus (DOF) can be increased by about 150 nm rather than using it.

  A combination of linearly polarized illumination and the small σ illumination method (an illumination method in which the σ value indicating the ratio between the numerical aperture NAi of the illumination system and the numerical aperture NAp of the projection optical system is 0.4 or less) is also effective.

  Further, for example, an ArF excimer laser is used as the exposure light, and a fine line and space pattern (for example, a line and space of about 25 to 50 nm) is formed on the substrate by using the projection optical system PL with a reduction magnification of about 1/4. When exposing on P, depending on the structure of the mask M (for example, the fineness of the pattern and the thickness of chrome), the mask M acts as a polarizing plate due to the Wave guide effect, and the P-polarized component (TM polarized light) that lowers the contrast. More diffracted light of the S-polarized component (TE polarized component) is emitted from the mask M than the diffracted light of the component. In this case, it is desirable to use the above-mentioned linearly polarized illumination, but even if the mask M is illuminated with random polarized light, it is high even when the numerical aperture NA of the projection optical system PL is as large as 0.9 to 1.3. Resolution performance can be obtained.

  When an extremely fine line-and-space pattern on the mask M is exposed on the substrate P, the P-polarized component (TM-polarized component) is larger than the S-polarized component (TE-polarized component) due to the Wire Grid effect. For example, an ArF excimer laser is used as exposure light, and a line and space pattern larger than 25 nm is exposed on the substrate P using the projection optical system PL with a reduction magnification of about 1/4. In this case, since the diffracted light of the S polarization component (TE polarization component) is emitted from the mask M more than the diffracted light of the P polarization component (TM polarization component), the numerical aperture NA of the projection optical system PL is 0.9. High resolution performance can be obtained even when the value is as large as -1.3.

  Furthermore, not only linearly polarized illumination (S-polarized illumination) matched to the longitudinal direction of the line pattern of the mask (reticle) but also a circle centered on the optical axis as disclosed in JP-A-6-53120. A combination of the polarization illumination method that linearly polarizes in the tangential (circumferential) direction and the oblique incidence illumination method is also effective. In particular, when not only a line pattern extending in a predetermined direction but also a plurality of line patterns extending in different directions (a mixture of line and space patterns having different periodic directions) is included in the mask (reticle) pattern, Similarly, as disclosed in Japanese Patent Laid-Open No. 6-53120, an aperture of the projection optical system can be obtained by using both the polarization illumination method that linearly polarizes in the tangential direction of the circle centered on the optical axis and the annular illumination method. Even when the number NA is large, high imaging performance can be obtained. For example, a polarized illumination method and an annular illumination method (annular ratio) in which a half-tone phase shift mask having a transmittance of 6% (a pattern having a half pitch of about 63 nm) is linearly polarized in a tangential direction of a circle around the optical axis. 3/4), when the illumination σ is 0.95 and the numerical aperture of the projection optical system PL is NA = 1.00, the depth of focus (DOF) is more than that of using randomly polarized light. If the projection optical system has a numerical aperture NA = 1.2 with a pattern with a half pitch of about 55 nm, the depth of focus can be increased by about 100 nm.

  Further, in addition to the above-described various illumination methods, for example, a progressive focus exposure method disclosed in JP-A-4-277612 and JP-A-2001-345245, or exposure light with multiple wavelengths (for example, two wavelengths) is used. It is also effective to apply a multi-wavelength exposure method that obtains the same effect as the progressive focus exposure method.

  As described above, in the projection optical system PL in the second embodiment, the optical characteristics of the projection optical system PL, for example, aberration (spherical aberration, coma aberration, etc.) can be adjusted by the optical element 2F. The optical element attached to the tip of the projection optical system PL may be an optical plate used for adjusting the optical characteristics of the projection optical system PL. Alternatively, also in the second embodiment, as in the first embodiment, the optical element 2F may be a plane parallel plate that can transmit the exposure light EL.

  When the pressure between the optical element at the tip of the projection optical system PL generated by the flow of the liquid LQ and the substrate P is large, the optical element is not exchangeable but the optical element is moved by the pressure. It may be fixed firmly so that there is no.

  In the second embodiment, the space between the projection optical system PL and the surface of the substrate P is filled with the liquid LQ. For example, a state in which a cover glass made of a plane parallel plate is attached to the surface of the substrate P. The liquid LQ may be filled.

The liquid LQ for forming the immersion region LR is water, but may be a liquid other than water. For example, when the light source of the exposure light EL is an F ₂ laser, the F ₂ laser light is Since it does not transmit water, the liquid LQ may be, for example, a fluorinated fluid such as perfluorinated polyether (PFPE) or fluorinated oil that can transmit F ₂ laser light. In this case, the lyophilic treatment is performed by forming a thin film with a substance having a molecular structure having a small polarity including fluorine, for example, at a portion in contact with the liquid LQ. In addition, as the liquid LQ, the liquid LQ is transmissive to the exposure light EL, has a refractive index as high as possible, and is stable with respect to the photoresist applied to the projection optical system PL and the surface of the substrate P (for example, Cedar). Oil) can also be used. Also in this case, the surface treatment is performed according to the polarity of the liquid LQ to be used.

  The substrate P of the first and second embodiments described above is used not only for semiconductor wafers for manufacturing semiconductor devices, but also for glass substrates for display devices, ceramic wafers for thin film magnetic heads, or exposure apparatuses. A mask or reticle master (synthetic quartz, silicon wafer) or the like to be applied is applied.

  As the exposure apparatuses EX1 and EX2, in addition to a step-and-scan type scanning exposure apparatus (scanning stepper) that scans and exposes the pattern of the mask M by synchronously moving the mask M and the substrate P, the mask M and the substrate The present invention can also be applied to a step-and-repeat projection exposure apparatus (stepper) in which the pattern of the mask M is collectively exposed while P is stationary, and the substrate P is sequentially moved stepwise.

  Further, as the exposure apparatuses EX1 and EX2, the reduced image of the first pattern is projected in a state where the first pattern and the substrate P are substantially stationary (for example, a refraction type projection optical system that does not include a reflective element at 1/8 reduction magnification). The present invention can also be applied to an exposure apparatus that performs batch exposure on the substrate P using a system. In this case, after that, with the second pattern and the substrate P substantially stationary, a reduced image of the second pattern is collectively exposed onto the substrate P by partially overlapping the first pattern using the projection optical system. It can also be applied to a stitch type batch exposure apparatus. Further, the stitch type exposure apparatus can be applied to a step-and-stitch type exposure apparatus in which at least two patterns are partially transferred on the substrate P, and the substrate P is sequentially moved.

  The present invention can also be applied to a twin stage type exposure apparatus disclosed in Japanese Patent Application Laid-Open No. 10-163099, Japanese Patent Application Laid-Open No. 10-214783, and Japanese Translation of PCT International Publication No. 2000-505958.

  The present invention can also be applied to an exposure apparatus having a substrate stage and a measurement stage as disclosed in JP-A-11-135400.

  The types of the exposure apparatuses EX1 and EX2 are not limited to the exposure apparatus for manufacturing a semiconductor element that exposes a semiconductor element pattern onto the substrate P. The exposure apparatus for manufacturing a liquid crystal display element or display, a thin film magnetic head, and an imaging element (CCD) or an exposure apparatus for manufacturing a reticle or mask can be widely applied.

  As described above, the exposure apparatus EX according to the present embodiment maintains various mechanical subsystems including the respective constituent elements recited in the claims of the present application so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. Manufactured by assembling. In order to ensure these various accuracies, before and after assembly, various optical systems are adjusted to achieve optical accuracy, various mechanical systems are adjusted to achieve mechanical accuracy, and various electrical systems are Adjustments are made to achieve electrical accuracy. The assembly process from the various subsystems to the exposure apparatus includes mechanical connection, electrical circuit wiring connection, pneumatic circuit piping connection and the like between the various subsystems. Needless to say, there is an assembly process for each subsystem before the assembly process from the various subsystems to the exposure apparatus. When the assembly process of the various subsystems to the exposure apparatus is completed, comprehensive adjustment is performed to ensure various accuracies as the entire exposure apparatus. The exposure apparatus is preferably manufactured in a clean room where the temperature, cleanliness, etc. are controlled.

  As shown in FIG. 11, a microdevice such as a semiconductor device includes a step 201 for designing a function / performance of the microdevice, a step 202 for producing a mask (reticle) based on the design step, and a substrate as a substrate of the device. Manufacturing step 203, exposure processing step 204 for exposing the mask pattern onto the substrate by the exposure apparatus EX of the above-described embodiment, device assembly step (including dicing process, bonding process, packaging process) 205, inspection step 206, etc. It is manufactured after.

It is a schematic block diagram which shows the exposure apparatus which concerns on 1st Embodiment. It is sectional drawing which shows the holding | maintenance apparatus which concerns on 1st Embodiment. It is a schematic diagram which shows the adjustment procedure of a holding | maintenance apparatus. It is a schematic diagram which shows the adjustment procedure of a holding | maintenance apparatus. It is a figure which shows the state which removed some members of the holding | maintenance apparatus. It is a perspective view for demonstrating the holding part of a holding device. It is a sectional side view of a holding device. It is the figure which looked at the holding | maintenance apparatus from the bottom. It is a schematic block diagram which shows the exposure apparatus which concerns on 2nd Embodiment. It is sectional drawing which shows the holding | maintenance apparatus which concerns on 2nd Embodiment. It is a flowchart figure which shows an example of the manufacturing process of a semiconductor device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Holding device, 2A-2F ... Optical element, 12 ... Liquid supply port, 22 ... Liquid recovery port, 30 ... 1st sealing member, 31 ... Upper surface (plane), 33 ... Spacer member (adjustment mechanism), 34 ... First 2 seal members, 38 ... peripheral edge, 39 ... inner peripheral surface, 41 ... first frame member, 42 ... second frame member, 43 ... opposed surface, 70 ... nozzle member (annular member), 80 ... third seal member, 90 ... cover member, 150 ... immersion mechanism, EX1, EX2 ... exposure device, G1 ... gap (gap), K1 ... internal space (first space), K2 ... external space (second space), LQ ... liquid, P ... Substrate, PK ... Tube, PL ... Projection optical system

Claims (12)

A holding device that holds an optical element disposed at a boundary between a first space and a second space different from the first space,
A first frame member that supports a peripheral portion of the optical element;
A second frame member attached to the first frame member and having a facing surface facing an inner circumferential surface inside the peripheral edge portion of the surface of the optical element;
In order to suppress the flow of gas between the first space and the second space, between the inner peripheral surface and the facing surface, the surface is in contact with the facing surface and is not in contact with the inner peripheral surface. A holding device comprising: a first seal member arranged in contact.   The holding device according to claim 1, wherein the first seal member has a flat surface facing the inner peripheral surface and is formed in a ring shape.   The holding apparatus according to claim 2, further comprising an adjustment mechanism that adjusts a gap between an inner peripheral surface of the optical element and a plane of the first seal member.   The holding device according to claim 3, wherein the adjustment mechanism includes a spacer member disposed between the first seal member and the facing surface.   In order to suppress the flow of gas between the first space and the second space, a second seal member disposed between the first seal member and the facing surface is provided. The holding device according to any one of claims 1 to 4.   The holding device according to claim 1, wherein the second frame member includes a cover member formed of a material different from that of the second frame member. In a lens barrel that holds a plurality of optical elements,
The optical device disposed between the internal space of the lens barrel and the external space of the lens barrel among the plurality of optical elements is held by the holding device according to any one of claims 1 to 6. A lens barrel characterized by that. In an exposure apparatus that exposes a substrate via a projection optical system,
The projection optical system is composed of a plurality of optical elements,
The exposure apparatus characterized in that an optical element arranged closest to the image plane of the projection optical system among the plurality of optical elements is held by the holding device according to any one of claims 1 to 6. apparatus. An immersion mechanism for filling a liquid between the projection optical system and the substrate;
The exposure apparatus according to claim 8, wherein the substrate is exposed through the projection optical system and the liquid. The liquid immersion mechanism is provided so as to surround a side surface of the optical element in contact with the liquid in the projection optical system, and includes an annular member having at least one of a liquid supply port and a liquid recovery port,
The exposure apparatus according to claim 9, further comprising a third seal member that prevents liquid from entering between a side surface of the optical element and the annular member.   The exposure apparatus according to claim 9, wherein the cover member is disposed between the second frame member and the liquid on the substrate.   A device manufacturing method using the exposure apparatus according to any one of claims 8 to 11.

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