JP5272584B2 - Shielding unit, variable slit device, and exposure device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize a mechanism for adjusting an illumination area, a light quantity or the like of illuminating light and to enhance the reliability of the mechanism. <P>SOLUTION: A blind unit for adjusting illuminating light includes: a fixed part 39b; a blade part 39a shielding a part of the illuminating light; parallel translating members 39c and 39d supporting both end parts of the fixed part 39b from the blade part 39a; and an ultrasonic motor 40 which is disposed between the fixed part 39b and the blade part 39a and moves the blade part 39a with respect to the fixed part 39b in order to adjust the quantity of shielded light of the illuminating light. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to, for example, a light shielding unit for adjusting the amount of illumination light, a variable slit device for forming the shape of illumination light into a slit shape, an exposure technique using the variable slit apparatus, and a device using the exposure technique It relates to manufacturing technology.

  For example, when a semiconductor device or the like is manufactured, a mercury lamp is conventionally used as exposure light in order to transfer and expose a pattern formed on a reticle (or photomask or the like) onto a wafer (or glass plate or the like) coated with a resist. An exposure apparatus that uses light from the far ultraviolet region to the vacuum ultraviolet region, such as a bright line or an excimer laser beam, is used. Recently, an exposure apparatus that uses extreme ultraviolet light (hereinafter referred to as EUV light) having a wavelength of, for example, about 100 nm or less as exposure light in order to shorten the exposure wavelength and improve resolution (hereinafter referred to as EUV exposure apparatus). Is also being developed.

Among these exposure apparatuses, in a scanning exposure apparatus (such as a scanning stepper) that moves a reticle and a wafer synchronously with respect to a projection optical system to expose the wafer, the illumination area on the reticle is in the scanning direction. It is set in a slit shape such as an elongated rectangular shape or an arc shape in a non-scanning direction orthogonal to. Conventionally, in order to set the slit-shaped illumination area, for example, a first blind having a plurality of movable blades defining the shape of one long side of the illumination area, and the shape of the other of the illumination area are almost defined. A variable blind having a second blind having an edge portion such as a straight line or an arc is used (for example, see Patent Document 1). The drive mechanism of the movable blade is composed of, for example, a box-like support portion including a bearing that movably supports the movable blade, and a motor that moves the movable blade in and out of the support portion.
International Publication No. 2005/048326 Pamphlet

In order to control the shape of the illumination area with high accuracy in the variable blind, it is necessary to arrange a plurality of narrow-width movable blades close to each other in the non-scanning direction. For this purpose, it is necessary to downsize the drive mechanism of the movable blade.
Moreover, since the movable blind is provided with a plurality of movable blades, the maintenance interval of the movable blind is shortened if the reliability of the individual movable blades and the driving mechanism thereof is low. In particular, in an EUV exposure apparatus, an optical system including a variable blind is arranged in a vacuum chamber in order to keep the optical path of exposure light in a vacuum. Therefore, it is necessary to increase the reliability of the mechanism part of the movable blind in order to reduce the frequency of maintenance of the apparatus arranged in the vacuum chamber and improve the operating rate of the exposure apparatus.

  In view of such circumstances, the present invention is used for adjusting (controlling) an illumination area or a light amount of illumination light, and is easily reduced in size and highly reliable, and uses the optical device. An object is to provide an exposure technique and a device manufacturing technique.

A light shielding unit according to the present invention is provided in a unit main body having a fixed portion, a light shielding portion, and two parallel moving members that translate the light shielding portion relative to the fixed portion, and an internal space of the unit main body. And a drive mechanism for moving the light shielding portion relative to the fixed portion.
The variable slit device according to the present invention is a variable slit device that forms the shape of illumination light into a predetermined shape, and includes a plurality of light shielding units according to the present invention, and the light shielding portions of the plurality of light shielding units are arranged in parallel. It is a thing.

An exposure apparatus according to the present invention includes the variable slit device according to the present invention in an exposure apparatus that illuminates a pattern with exposure light and exposes the substrate with the exposure light through the pattern and the projection optical system. A part of the exposure light is shielded by the light shielding part of the apparatus.
A device manufacturing method according to the present invention includes exposing a photosensitive substrate using the exposure apparatus of the present invention and processing the exposed photosensitive substrate.

According to the present invention, it is possible to adjust (control) the illumination area or the light amount of illumination light by a mechanism that is easy to miniaturize and moves with high reliability by moving the light shielding unit with respect to the fixed unit.

An example of an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 schematically shows the overall configuration of an exposure apparatus (EUV exposure apparatus) 100 that uses EUV light having a wavelength of, for example, 11 nm or 13 nm within a range of about 3 to 50 nm as exposure light EL (illumination light) of the present embodiment. FIG. In FIG. 1, an exposure apparatus 100 includes a laser plasma light source 10 that generates exposure light EL, an illumination optical system ILS that illuminates a reticle R (mask) with the exposure light EL, and a reticle stage RST that holds and moves the reticle R. And a projection optical system PO that projects an image of the pattern formed on the pattern surface (reticle surface) of the reticle R onto a wafer W (photosensitive substrate) coated with a resist (photosensitive material). Further, the exposure apparatus 100 includes a wafer stage WST that holds and moves the wafer W, a main control system 31 that includes a computer that controls the overall operation of the apparatus, and the like.

In the present embodiment, since EUV light is used as the exposure light EL, the illumination optical system ILS and the projection optical system PO are composed of a plurality of reflective optical members except for a specific filter or the like (not shown). R is also a reflection type. A multilayer reflective film that reflects EUV light is formed on the reflective surface and reticle surface of these reflective optical members. A circuit pattern is formed by an absorption layer on the reflective film on the reticle surface. In order to prevent the exposure light EL from being absorbed by the gas, the exposure apparatus 100 is accommodated in the box-like vacuum chamber 1 as a whole, and the space in the vacuum chamber 1 is evacuated through the exhaust pipes 32Aa, 32Ba and the like. Large vacuum pumps 32A, 32B and the like are provided. Further, a plurality of sub-chambers (not shown) are provided in order to further increase the degree of vacuum on the optical path of the exposure light EL in the vacuum chamber 1. As an example, the pressure in the vacuum chamber 1 is about 10 ⁻⁵ Pa, and the pressure in the subchamber (not shown) that houses the projection optical system PO in the vacuum chamber 1 is about 10 ⁻⁵ to 10 ⁻⁶ Pa.

  Hereinafter, in FIG. 1, the Z-axis is taken in the normal direction of the surface (bottom surface of the vacuum chamber 1) on which wafer stage WST is placed, and the X-axis is perpendicular to the paper surface of FIG. A description will be given taking the Y axis parallel to the paper surface of FIG. In the present embodiment, the illumination area 27R of the exposure light EL on the reticle surface has an arc shape elongated in the X direction, and the reticle R and the wafer W are in the Y direction (scanning direction) with respect to the projection optical system PO during exposure. Scanned synchronously.

  First, the laser plasma light source 10 includes a high-power laser light source (not shown), a condensing lens 12 that condenses laser light supplied from the laser light source through the window member 15 of the vacuum chamber 1, and xenon or The gas jet cluster type light source includes a nozzle 14 for ejecting a target gas such as krypton and a condensing mirror 13 having a spheroidal reflection surface. The exposure light EL emitted from the laser plasma light source 10 is condensed on the second focal point of the condenser mirror 13. The exposure light EL condensed at the second focal point becomes a substantially parallel light beam via the concave mirror 21, and an optical integrator comprising a pair of fly-eye optical systems 22 and 23 for uniformizing the illuminance distribution of the exposure light EL. Led to. More specific configurations and operations of the fly-eye optical systems 22 and 23 are disclosed in, for example, US Pat. No. 6,452,661.

  In FIG. 1, the surface in the vicinity of the reflecting surface of the fly-eye optical system 23 is the pupil surface of the illumination optical system ILS, and the aperture stop AS is disposed at this pupil surface or at a position near this pupil surface. The aperture stop AS typically represents a plurality of aperture stops having openings of various shapes. By changing the aperture stop AS under the control of the main control system 31, the illumination condition can be switched to normal illumination, annular illumination, dipole illumination, quadrupole illumination, or the like.

  The exposure light EL that has passed through the aperture stop AS is once condensed and then incident on the curved mirror 24. The exposure light EL reflected by the curved mirror 24 is reflected by the concave mirror 25 and then elongated in the X direction and in the + Y direction. After passing the edge portion of the substantially arc-shaped blind plate 26, the arc-shaped illumination region 27R on the pattern surface of the reticle R is illuminated obliquely from below with a uniform illuminance distribution. The curved mirror 24 and the concave mirror 25 constitute a condenser optical system. By the condenser optical system, light from a number of reflection mirror elements of the second fly's eye optical system 23 illuminates the illumination area 27R on the reticle surface in a superimposed manner. In the example of FIG. 1, the curved mirror 24 is a convex mirror, but the curved mirror 24 may be formed of a concave mirror, and the curvature of the concave mirror 25 may be reduced by that amount. The illumination optical system ILS includes the concave mirror 21, the fly-eye optical systems 22 and 23, the aperture stop AS, the curved mirror 24, and the concave mirror 25. The configuration of the illumination optical system ILS is arbitrary. For example, a mirror may be disposed between the concave mirror 25 and the reticle R in order to further reduce the incident angle of the exposure light EL with respect to the reticle surface.

  Further, the exposure light EL reflected by the illumination area 27R of the reticle R is partially shielded from light by the tip portions of the blade portions 39a of the plurality of blind units 38 arranged in the X direction and enters the projection optical system PO. The exposure light EL that has passed through the projection optical system PO is projected onto an exposure region (region conjugate to the illumination region 27R) 27W on the wafer W. In this case, a variable blind (variable field stop) 35 that defines the shape of the illumination area 27R and, consequently, the shape of the exposure area 27W, is configured including the blind plate 26 and a large number of blind units 38 (details will be described later). Note that the reticle surface and the arrangement surface of the fly-eye optical system 22 are conjugate, and the rough shape of the illumination area 27R is also defined by the shape of the individual mirror elements constituting the fly-eye optical system 22.

In addition, the exposure area 27W is closed in the Y direction (scanning direction) at the start and end of the scanning exposure of each shot area (die) on the wafer W, and the width of the exposure area 27W (illumination area 27R) in the X direction is defined. For example, a blind for opening and closing may be disposed in the vicinity of the blind plate 26 or on a conjugate plane with the reticle surface.
Next, the reticle R is attracted and held on the bottom surface of the reticle stage RST via the electrostatic chuck RH. Reticle stage RST is driven by a drive system (not shown) along a guide surface parallel to the XY plane of the outer surface of vacuum chamber 1 based on a measurement value of a laser interferometer (not shown) and control information of main control system 31. It is driven with a predetermined stroke in the Y direction, and is also driven by a minute amount in the X direction and the θz direction (rotating direction around the Z axis). A partition 8 is provided so as to cover the reticle stage RST on the vacuum chamber 1 side, and the inside of the partition 8 is maintained at an atmospheric pressure between the atmospheric pressure and the atmospheric pressure in the vacuum chamber 1 by a vacuum pump (not shown).

  On the pattern surface side of the reticle R, there is an optical reticle autofocus system (not shown) that measures the position in the Z direction (Z position) of the reticle surface by, for example, irradiating measurement light obliquely to the reticle surface. Has been placed. Based on the measurement value of the reticle autofocus system during scanning exposure, the main control system 31 uses the Z drive mechanism (not shown) in the reticle stage RST to bring the Z position in the Z direction of the reticle R within an allowable range. Set.

  As an example, the projection optical system PO is configured by holding six mirrors M1 to M6 with a lens barrel (not shown). The projection optical system PO is non-telecentric on the object (reticle R) side and telecentric on the image (wafer W) side. It is a reflection system, and the projection magnification is a reduction magnification such as 1/4. The exposure light EL reflected by the illumination area 27R of the reticle R forms a reduced image of a part of the pattern of the reticle R on the exposure area 27W on the wafer W via the projection optical system PO.

  In the projection optical system PO, the exposure light EL from the reticle R is reflected upward (+ Z direction) by the mirror M1, subsequently reflected downward by the mirror M2, then reflected upward by the mirror M3, and reflected by the mirror M4. Reflected downward. Next, the exposure light EL reflected upward by the mirror M5 is reflected downward by the mirror M6 to form an image of a part of the pattern of the reticle R on the wafer W. As an example, the mirrors M1, M2, M4, and M6 are concave mirrors, and the other mirrors M3 and M5 are convex mirrors. The projection optical system PO is not limited to the configuration shown in FIG. 1, and the number of reflection optical members may be any number other than six.

  On the other hand, wafer W is attracted and held on wafer stage WST via an electrostatic chuck (not shown). Wafer stage WST is arranged on a guide surface arranged along the XY plane. Wafer stage WST is driven at a predetermined stroke in the X and Y directions by a drive mechanism (not shown) based on the measurement value of a laser interferometer (not shown) and the control information of main control system 31, and is necessary. Accordingly, it is also driven in the θz direction.

  In the vicinity of wafer W on wafer stage WST, for example, a dose monitor 29 including a plurality of photoelectric sensors arranged in the X direction is installed, and a detection signal of dose monitor 29 is supplied to main control system 31. . Illuminance (or pulse energy) of exposure light EL for each measurement position in the X direction of exposure area 27W (illumination area 27R) by driving wafer stage WST and moving the light receiving surface of dose monitor 29 to exposure area 27W. ) Can be measured. Based on this measurement result, the main control system 31 uses the variable blind 35 so that the integrated exposure amount at each point on the wafer W scanned with respect to the exposure area 27W becomes uniform via the blind control system 33. The width in the Y direction (slit width) of each position in the X direction of the illumination area 27R is controlled (details will be described later).

At the time of exposure, the wafer W is disposed inside the partition 7 so that the gas generated from the resist on the wafer W does not adversely affect the mirrors M1 to M6 of the projection optical system PL. The partition 7 is formed with an opening through which the exposure light EL is passed, and the space in the partition 7 is evacuated by a vacuum pump (not shown).
When exposing one shot area (die) on the wafer W, the exposure light EL is irradiated onto the illumination area 27R of the reticle R by the illumination optical system ILS, and the reticle R and the wafer W are projected onto the projection optical system PO. It moves synchronously in the Y direction at a predetermined speed ratio according to the reduction magnification of the optical system PO (synchronous scanning). In this way, the reticle pattern is exposed to one shot area on the wafer W. Thereafter, after the wafer stage WST is driven to move the wafer W stepwise, the pattern of the reticle R is scanned and exposed to the next shot area on the wafer W. In this way, a pattern image of the reticle R is sequentially exposed to a plurality of shot areas on the wafer W by the step-and-scan method.

Next, the variable blind 35 of the exposure apparatus 100 of this embodiment will be described.
2A is a perspective view showing a main part of the variable blind 35 in FIG. 1, FIG. 2B is an enlarged view of a part of FIG. 2A viewed from the −Y direction, and FIG. It is the top view which abbreviate | omitted a part of 2 (A) variable blind 35. FIG. In FIG. 3, the shape of the edge portion 27Rb in the −Y direction of the arcuate illumination region 27R on the reticle R is defined by the blind plate 26 in FIG. Further, the shape of the edge portion 27Ra in the + Y direction of the arcuate illumination area 27R on the reticle R is at a plurality of positions Pi (i = 1, 2,...) Set in the X direction on the frame 36 at a predetermined cycle. , Defined by blind units 38 arranged close to the X direction. The blind unit 38 is fixed to the frame 36 by bolts 50 (see FIG. 2B) from the bottom side, for example. Note that the plurality of blind units 38 on the −X direction side in FIG. 3 are not shown. For convenience of explanation, the number of blind units 38 in FIG. 2A is different from the number of blind units 38 in FIG. Yes. As the number of blind units 38 (blades 39a) increases, the shape of the illumination area 27R can be controlled with higher accuracy (with a fine width in the X direction). The number of blind units 38 is, for example, about 10 to several tens.

The plurality of blind units 38 in FIG. 2 have substantially the same configuration except for the shape of the distal end portion of the blade portion 39a described later and the positions of the ultrasonic motor 40 and the encoder 43 in the Y direction. Therefore, the configuration of one blind unit 38 will be typically described.
FIG. 4 is an enlarged view showing one blind unit 38 among the plurality of blinds shown in FIG. In FIG. 4, the blind unit 38 includes a unit main body 39 and an ultrasonic motor 40 that drives the unit main body 39. The unit main body 39 is fixed to the frame 36 and has a fixing portion 39b elongated in the Y direction, a blade portion 39a, and a pair of parallel moving members 39c and 39d for displacing the blade portion 39a in the Y direction with respect to the fixing portion 39b. Is provided. The blade portion 39a includes a tip portion 39at that is gradually thinned at the tip and is directly irradiated with exposure light, and a support member 39au that supports the tip portion 39at, is elongated in the Y direction, and has substantially the same length as the fixed portion 39b. It is out. Each of the translation members 39c and 39b has a substantially rectangular cross section. The parallel movement member 39c connects one end (the end on the tip 39at side) of both ends of the support member 39au and one end (the end on the −Y direction side) of both ends of the fixed portion 39b. The parallel moving member 39d includes the other end (the end opposite to the tip 39at) of both ends of the support member 39au and the other end (the end on the + Y direction side) of both ends of the fixed portion 39b. ).

  In addition, in order to give flexibility to the four connecting portions of the translation members 39c and 39d, the fixed portion 39b, and the support member 39au, a hinge portion 39e made of a slit portion is provided. The unit main body 39 can be integrally formed from one flat plate by wire cutting or punching. In the unit main body 39 configured as described above, the tip end portion 39at protrudes in front of the parallel movement member 39c, and the fixing portion 39b is fixed to the frame 36 with a bolt 50 (FIG. 2B).

  As shown in FIG. 2A, since the illumination area 27R has an arc shape, the tip portions 39at (see FIG. 4) of the blade portions 39a of the plurality of blind units 38 have both ends (for example, position P1) in the Y direction. The length of the blade portion 39a is the shortest, and the central blade portion 39a is set longer. By controlling the position in the Y direction of the blade portion 39a of the blind unit 38 at the position Pi, the width (slit width) hi in the Y direction of the illumination area 27R at the position Pi can be individually controlled. For example, in the initial state, the light shielding width in the Y direction of the exposure light by the blade portions 39a of all the blind units 38 is substantially the same, and the slit width hi of the illumination region 27R is also set to be substantially the same.

  In FIG. 3, on the upper surface of the blade portion 39a of the unit main body 39 constituting each blind unit 38, a scale portion 42 in which a lattice pattern having a predetermined period in the Y direction is formed by gradually changing the position in the Y direction. It is fixed. Further, a detector 41 indicated by a dotted line for detecting the displacement of the scale portion 42 in the Y direction is disposed above each scale portion 42. The scale unit 42 and the detector 41 constitute a detection device such as an encoder. The detector 41 is fixed to the bottom surface of the cover member 37 fixed to the frame 36 as shown in FIG. The encoder is, for example, a reflective optical linear encoder, and the detector 41 has a resolution of about 0.05 μm within a stroke of about 1 to several mm, for example, in the Y direction displacement of the scale unit 42 and eventually the blade unit 39a. And the measurement result is supplied to the blind control system 33 in FIG. In this case, the width of the detector 41 in the X direction is about three times the width of the unit body 39, and the length in the Y direction is about 1/3 or less of the length of the unit body 39. Therefore, by setting the Y-direction position of the scale portion 42 (encoder) on the blade portion 39a to three different positions, the unit main body 39 can be arranged in a state in which the plurality of unit main bodies 39 are arranged close to the X direction. The encoders can be arranged so that the upper scale portions 42 can be detected and do not interfere mechanically.

  Further, in FIG. 2A, an ultrasonic motor 40 that is operable in a vacuum for moving the blade portion 39a in the Y direction is fixed inside the unit main body 39 of the blind unit 38. That is, a part of the ultrasonic motor 40 is disposed in a space formed by the support member 39au, the pair of parallel movement members 39c and 39d, and the fixed portion 39b. The width of the ultrasonic motor 40 in the X direction is also about three times the width of the unit body 39 in the X direction. Then, the position of the ultrasonic motor 40 in the adjacent unit main body 39 in the Y direction is set in three stages so that the ultrasonic motor 40 does not mechanically interfere with the unit main body 39 placed close to the X direction. It has changed. Therefore, the remaining part of the ultrasonic motor 40 is accommodated in the adjacent unit main body 39.

  Further, as shown in FIG. 2B, the blind control system 33 is set so that the position of the blade portion 39a in the Y direction becomes the position set in the main control system 31 based on the detection result of the encoder. The blade portion 39a is driven in the Y direction via the sonic motor 40. Further, as an example, an extension portion 39f extending in the −X direction is provided at the tip portion of the blade portion 39a so that exposure light does not leak from between the tip portions of the blade portions 39a of the two adjacent blind units 38, and the extension portion. A recess 39g in which 39f is installed is formed.

  The unit main body 39 can be formed of a metal having high heat resistance such as beryllium (Be) or chromium-molybdenum steel. It should be noted that only the tip 39at that is actually irradiated with the exposure light is formed from a high heat-resistant ceramic such as zirconia, or a high heat-resistant metal such as beryllium or chromium-molybdenum steel, and the support member 39au and the translation member 39c. , 39d and the fixing portion 39b may be formed of an inexpensive and easy-to-work metal such as stainless steel.

  Further, the length L1 in the Y direction of the inner fixed portion 39b and the blade portion 39a of the parallel moving members 39c and 39d is set to a degree that is slightly more than three times the length L2 of the ultrasonic motor 40 in the Y direction. ing. Furthermore, in the embodiment of FIG. 4, convex portions 39h and 39i having a length of about 1/3 of L1 are formed inside the −Y-direction ends of the fixed portion 39b and the blade portion 39a, respectively. An ultrasonic motor 40 is installed between the convex portion 39i. The ultrasonic motor 40 is fixed by, for example, a bolt 51 from the fixing portion 39b side, and the drive chips 40a and 40b of the ultrasonic motor 40 disposed at predetermined intervals in the Y direction are in contact with the convex portion 39i. As an example, the ultrasonic motor 40 is a resonance type, and the tip portions of the drive chips 40a and 40b are elliptically moved, so that the blade portion 39a has a stroke of, for example, about 1 mm in the + Y direction or the −Y direction with respect to the fixed portion 39b. Can be translated.

  4 is disposed at the positions P1 and P4 in FIG. 2A, and the unit body 39 disposed at the position P2 in FIG. Convex portions 39h and 39i are formed on A11 and A21, respectively, and the ultrasonic motor 40 is installed therebetween. Similarly, in the unit main body 39 disposed at the position P3 and the like in FIG. 2A, convex portions 39h and 39i are formed at positions A12 and A22 in FIG. 4, respectively, and the ultrasonic motor 40 is installed therebetween. In FIG. 4, the scale portion 42 is fixed to the end portion side in the −Y direction on the upper surface of the blade portion 39 a, but the scale is provided in each of the unit main bodies 39 arranged at the positions P <b> 2 and P <b> 3 in FIG. The portion 42 is fixed to the central portion of the blade portion 39a and the end portion in the + Y direction. However, the position of the ultrasonic motor 40 in the Y direction may be different from the position of the scale portion 42 (encoder 41) in the Y direction, and the number of ultrasonic motors 40 arranged in the Y direction (in FIG. 2A). (3 rows) and the number of detectors 41 arranged in the Y direction may be different. Further, the convex portions 39h and 39i are not necessarily provided.

  In this way, by shifting the positions of the ultrasonic motor 40 and the encoder (detector 41) in the adjacent unit main bodies 39 so as not to overlap in the Y direction, the ultrasonic motor whose width in the X direction is wider than the width of the unit main body 39. Even in the case of using 40 and the detector 41, the unit main body 39 (blind unit 38) can be arranged close to (or almost in close contact with) the X direction (non-scanning direction), and the variable blind 35 can be downsized. .

  When the blade portion 39a (tip portion 39at) of the unit main body 39 in FIG. 4 is displaced in the −Y direction, as shown in FIG. 5A, the blade portion 39a with respect to the fixed portion 39b by the ultrasonic motor 40. May be moved in the -Y direction. On the other hand, when the blade portion 39a is displaced in the + Y direction, the blade portion 39a may be moved in the + Y direction with respect to the fixed portion 39b by the ultrasonic motor 40 as shown in FIG. In these cases, the blade portion 39a (support member 39au) can be easily translated in the Y direction with respect to the fixed portion 39b by elastic deformation of the hinge portion 39e. The direction position can be smoothly controlled with high accuracy. In this case, the unit main body 39 is only elastically deformed, and the reliability is extremely high. Therefore, the members to be maintained in the blind unit 38 are substantially only the ultrasonic motor 40 and the detector 41, and the reliability of the blind unit 38 can be extremely increased.

Effects and the like of this embodiment are as follows.
(1) The blind unit 38 of the present embodiment is a unit for adjusting the shape of the illumination area 27R (or exposure area 27W) of exposure light, and includes a fixed portion 39b and a blade that blocks part of the exposure light. And an ultrasonic motor 40 that is disposed between the fixed portion 39b and the blade portion 39a and moves the blade portion 39a in the Y direction with respect to the fixed portion 39b.

Therefore, the shape (slit width) of the illumination area of the exposure light can be adjusted by moving the blade portion 39a in the Y direction by a small and highly reliable mechanism.
(2) Further, the fixed portion 39b and the blade portion 39a are arranged in parallel to the Y direction, and include translational members 39c and 39d that translate the blade portion 39a with respect to the fixed portion 39b. Therefore, the blade portion 39a can be driven in the Y direction with high accuracy without using a complicated mechanism such as a bearing.

(3) Further, the parallel moving members 39c and 39d connect both ends of the support member 39au of the blade portion 39a and both ends of the fixed portion 39b through hinge portions 39e, and a tip portion 39at that blocks exposure light is a link. It protrudes forward of the portion 39c. Therefore, only the tip 39at can be easily arranged in the optical path of the exposure light.
(4) Since the blade portion 39a is driven by the ultrasonic motor 40 with respect to the fixed portion 39b, the blade portion 39a can be driven with high accuracy even in a vacuum, for example. Furthermore, since the ultrasonic motor 40 has a holding power in a power-off state, the ultrasonic motor 40 can be turned off after the shape of the illumination area is set once during the exposure process, so that the control is easy. is there.

(5) Since the displacement of the scale portion 42 provided in the blade portion 39a is detected by the detector 41, the displacement of the blade portion 39a can be directly detected with high accuracy. Accordingly, the position of the blade portion 39a can be controlled with high accuracy.
(6) Further, in the variable blind 35 of FIG. 2A, the blade portions 39a of the plurality of blind units 38 are arranged close to each other in the X direction and along the same surface. Therefore, these blade portions 39a can be arranged on the field stop surface such as in the vicinity of the reticle R of the exposure apparatus, and the slit-like illumination region 27R (and thus the reticle R) on the reticle R can be controlled by controlling the position of the blade portion 39a in the Y direction. The width of the exposure area 27W) on the wafer W, and thus the amount of exposure light on the corresponding wafer W can be controlled with high accuracy.

  (7) In this case, the length in the Y direction of the fixed portion 39b and the blade portion 39a of the unit main body 39 of the variable blind 35 is preferably at least twice the length of the ultrasonic motor 40 in the Y direction. At this time, by arranging the ultrasonic motors 40 of the two adjacent variable blinds 35 at positions that do not overlap along the fixed portion 39b, the interval between the adjacent blade portions 39a in the X direction (non-scanning direction) is ultrasonic. Since the width of the motor 40 can be narrower than the width in the X direction, the variable blind 35 can be reduced in size.

  (8) The exposure apparatus 100 in FIG. 1 is a variable blind in an exposure apparatus that illuminates the pattern of the reticle R with the exposure light EL and exposes the wafer W with the exposure light EL through the pattern and the projection optical system PO. Part of the exposure light EL is shielded by the blade portions 39a of the 35 blind units 38. Therefore, by controlling the position of the blade portion 39a and controlling the amount of light shielding, the shape of the illumination area on the reticle R, and hence the shape of the exposure area on the wafer W, can be easily set to a desired shape, and scanning is performed. The integrated exposure amount at each point on the wafer W after exposure can be controlled with high accuracy. At this time, since the reliability of each blind unit 38 is improved, the frequency of maintenance of the variable blind 35 is reduced, and the operating rate of the exposure apparatus can be improved.

  (9) In this case, for example, the illuminance distribution in the X direction of the exposure area 27W is measured in advance by the dose monitor 29 on the wafer stage WST, and the illuminance distribution, for example, is determined by the blind control system 33 from the measurement result. By controlling the position of the blade portion 39a of each blind unit 38 so as to be uniform, the uniformity of the integrated exposure amount on the wafer W is improved.

The above embodiment can be modified as follows.
First, the unit main body 39A of FIG. 6 can be used instead of the unit main body 39 of the blind unit 38 of FIG. In FIG. 6, the unit main body 39A connects the end portions in the −Y direction of the fixed portion 39b and the blade portion 39a via the parallel moving member 39c and the hinge portion 39e, and the + Y direction between the fixed portion 39b and the blade portion 39a. Are connected by a tension coil spring 43. The other configuration is the same as that of FIG. 4, and an ultrasonic motor 40 for driving the blade portion 39i in the Y direction is installed between the convex portion 39h of the fixing portion 39b and the convex portion 39i of the blade portion 39a. ing.

According to the modified example of FIG. 6, the pressing force applied from the blade portion 39a to the ultrasonic motor 40 can be controlled by the biasing force of the tension coil spring 43 toward the fixed portion 39b, so that the ultrasonic motor 40 can be driven stably. .
In addition, as the unit main body 39, it is possible to use a link mechanism or the like in which a rotation shaft is provided in a portion corresponding to the hinge portion 39e.

  In the above-described embodiment, the arcuate illumination area 27R is set on the reticle surface. However, as shown in FIG. 7, a rectangular illumination area 27AR can be set on the reticle surface. In the case of FIG. 7, the length in the Y-axis direction of the blade portion 39a of the blind unit 38 at each position Qi (i = 1, 2,...) On the frame 36 may be the same. In this case, by controlling the position in the Y direction of the blade portion 39a at the position Qi so that the exposure amount distribution in the X direction in the exposure area corresponding to the illumination area 27AR is the same, the Y direction of the illumination area 27AR is controlled. The slit width hi is individually controlled.

In the above embodiment, an optical encoder is used to detect the displacement of the blade portion 39a. However, other sensors such as a capacitive sensor or a magnetic encoder are used for detecting the displacement. Can also be used.
In the above embodiment, the ultrasonic motor 40 is used to drive the blade portion 39a with respect to the fixed portion 39b. However, other driving mechanisms such as a voice coil motor or an EI core type actuator are also available. Can also be used.

In the above embodiment, the variable blind 35 in FIG. 1 is arranged in the vicinity of the reticle surface. However, the blind plate 26 and / or a large number of blind units 38 are conjugated with the reticle surface in the illumination optical system ILS. You may arrange | position in the vicinity of a surface.
Further, the variable blind 35 of FIG. 1 may be disposed between the projection optical system PO and the wafer W. In this case, the partition 7 may be omitted.
In the above-described embodiment, the laser plasma light source is used as the exposure light source. However, the present invention is not limited to this, and any of a SOR (Synchrotron Orbital Radiation) ring, a betatron light source, a discharged light source, an X-ray laser, and the like is used. May be.

  In the above embodiment, EUV light is used as exposure light. However, in the present invention, excimer laser light such as KrF (wavelength 248 nm) and ArF (wavelength 193 nm), or harmonics of a solid-state laser is used as exposure light. It is also applicable to an exposure apparatus using Further, when using exposure light that is transmitted even in a gas, the illumination optical system and the projection optical system may be a refractive system or a catadioptric system. In this case, the reticle may be a transmission type, and an illumination area as shown in FIG. 7 may be set on the reticle.

  When an electronic device (or microdevice) such as a semiconductor device is manufactured using the exposure apparatus of the above embodiment, the electronic device performs function / performance design of the electronic device as shown in FIG. Step 222 for manufacturing a mask (reticle) based on this design step, Step 223 for manufacturing a substrate (wafer) as a base material of the device and applying a resist, Exposure apparatus (EUV exposure apparatus) of the above-described embodiment The substrate processing step 224 including the step of exposing the mask pattern to the substrate (sensitive substrate), the step of developing the exposed substrate, the heating (curing) and etching step of the developed substrate, the device assembly step (dicing step, bonding) (Including processing processes such as process and package process) 225 and inspection It is produced through the step 226 or the like.

In other words, the device manufacturing method exposes a substrate (wafer) placed on the projection plane using the exposure apparatus of the above-described embodiment, and processes the exposed substrate (step 224). Including. At this time, according to the exposure apparatus of the above embodiment, since the operating rate of the exposure apparatus can be maintained high, a device can be manufactured with high accuracy and high throughput.
In addition, this invention is not limited to the above-mentioned embodiment, A various structure can be taken in the range which does not deviate from the summary of this invention.

It is sectional drawing which shows schematic structure of the exposure apparatus of an example of embodiment of this invention. (A) is a perspective view which shows the principal part of the variable blind 35 in FIG. 1, (B) is the one part enlarged view which looked at the variable blind 35 of FIG. 2 (A) from -Y direction. It is the top view which abbreviate | omitted a part which shows the variable blind 35 of FIG. 2 (A). It is an enlarged view which shows the parallel displacement member 39 of the blind unit 38 of FIG. 2, and its drive mechanism. FIG. 5A is a diagram showing a state where the blade portion 39a of FIG. 4 is moved in the −Y direction, and FIG. 5B is a diagram showing a state where the blade portion 39a of FIG. 4 is moved in the + Y direction. It is a figure which shows the modification of a parallel displacement member. It is a perspective view which shows the structural example of the variable blind for setting a rectangular illumination area. It is a flowchart which shows an example of the manufacturing process of a device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vacuum chamber, ILS ... Illumination optical system, R ... Reticle, PO ... Projection optical system, W ... Wafer, 10 ... Laser plasma light source, 26 ... Blind plate, 27R ... Illumination area, 29 ... Irradiation monitor, 33 ... Blind Control system, 35 ... variable blind, 38 ... blind unit, 39 ... unit main body, 39a ... blade part, 39b ... fixed part, 39c, 39d ... translation member, 39e ... hinge part, 40 ... ultrasonic motor, 41 ... detection Vessel, 42 ... scale section

Claims (12)

A shading unit,
A unit body having a fixed part, a light shielding part, and two parallel movement members that translate the light shielding part relative to the fixed part ;
A drive mechanism that is provided in an internal space of the unit main body and moves the light shielding portion relative to the fixed portion;
A light-shielding unit comprising: The light-shielding unit according to claim 1 , wherein the fixing part and the light-shielding part are arranged in parallel to each other. The fixing portion is configured by a member having a shape extending in a direction in which the light shielding portion is moved in parallel.
The light shielding portion includes a blade that shields a part of the illumination light, and a support member that supports the blade and extends in a direction of translation by the translation member,
The translation member, the light shielding unit according to claim 1 or 2, characterized in that for connecting the at least one of both end portions of at least one said support member at both ends of the fixed part. The light-shielding unit according to claim 3, further comprising a hinge portion that connects the parallel movement member to at least one of both end portions of the fixed portion and at least one end portion of the support member. The light-shielding unit according to claim 4 , wherein the fixed portion, the support member, the parallel movement member, and the hinge portion are integrally formed with one member. The drive mechanism is, the light shielding unit according to claim 1, any one of 5, characterized in that it comprises an ultrasonic motor which is fixed to the fixed portion. And a detector that detects a displacement of the light shielding part with respect to the fixed part, the scale part being provided in a part of the light shielding part, and a detector that detects a displacement of the scale part. Item 7. The light shielding unit according to any one of Items 1 to 6 . A variable slit device that forms a shape of illumination light into a predetermined shape,
A plurality of the light shielding units according to any one of claims 1 to 7 ,
The variable slit device, wherein the light shielding portions of the plurality of light shielding units are arranged in parallel. The length of the light shielding unit in the direction of relative movement of the fixed portion and the light shielding portion is at least twice the length of the drive mechanism,
The variable slit device according to claim 8 , wherein the drive mechanisms of the two adjacent light shielding units are arranged at positions that do not overlap with the fixed portion. In an exposure apparatus that illuminates a pattern with exposure light and exposes the substrate through the pattern and the projection optical system with the exposure light,
The variable slit device according to claim 8 or 9 ,
An exposure apparatus characterized in that a part of the exposure light is shielded by the light shielding portion of the variable slit device. A measuring device for measuring light quantity information of the exposure light;
The exposure apparatus according to claim 10 , further comprising: an adjustment device that adjusts a light shielding amount of the exposure light by the light shielding unit of the variable slit device according to a measurement result of the measurement device. Exposing a photosensitive substrate using the exposure apparatus according to claim 10 or 11,
Processing the exposed photosensitive substrate.

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