JP2011108697A - Method of controlling amount of exposure, exposure method, and method of manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control the amount of exposure to a substrate by reducing irregularities in the amount of exposure and variations in illumination conditions when performing scanning exposure of the substrate in an irradiation region. <P>SOLUTION: A method of controlling the amount of exposure when exposing a wafer to light by scanning the wafer in the Y direction to the irradiation region 27W includes: a process of measuring light intensity distribution in the X direction of the irradiation region 27W; a process of adjusting width in the Y direction of the irradiation region 27W for each of a plurality of positions in the X direction according to the measurement results; and a process of adjusting width of one intensity inclination section 65B of the irradiation region 27W where light intensity of exposure light decreases gradually for each position in the X direction according to the width in the Y direction of the irradiation region 27W. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an exposure control technique for controlling an exposure amount on a substrate, an exposure technique using the exposure control technique, and a device manufacturing technique using the exposure technique.

  For example, when manufacturing a semiconductor device or the like, an exposure apparatus used to transfer and expose a pattern formed on a reticle (or a photomask or the like) onto a wafer (or glass plate or the like) coated with a resist. For example, light from the far ultraviolet region to the vacuum ultraviolet region such as an emission line of a mercury lamp or excimer laser light, or extreme ultraviolet light (Extreme Ultraviolet Light: hereinafter referred to as EUV light) having a wavelength of about 100 nm or less is used.

  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, an irradiation area for exposing the wafer is scanned. It is set to a slit shape such as an elongated rectangle or an arc shape in a direction orthogonal to the direction. Conventionally, in order to set the slit-shaped irradiation area, for example, a first blind having a plurality of movable blades defining the shape of one long side of the irradiation area, and the shape of the other long side of the irradiation area A variable blind having a second blind having a substantially straight or arcuate edge portion that defines the above is used (see, for example, Patent Document 1). In addition, when using pulsed light such as excimer laser light or EUV light as exposure light in a scanning exposure apparatus, a variable blind is placed on the object surface in order to reduce exposure unevenness due to energy variations for each pulsed light. Defocusing is performed from a plane conjugate with (image plane), and the light intensity distribution in the irradiation region is changed to a trapezoidal shape in the scanning direction.

International Publication No. 2005/48326 Pamphlet

  In a conventional scanning exposure apparatus, if there is a part where the accumulated exposure after scanning exposure is larger than the allowable range, the variable blind blade is driven to control the exposure. It is conceivable to narrow the width (slit width) in the scanning direction of the irradiation region to be performed. However, when the exposure light is pulsed light, simply narrowing the slit width of that part is caused by variations in the energy of the pulsed light emission under the exposure conditions where the number of exposure pulses to the exposed part of the wafer passing through that part is small. There is a problem that unevenness in exposure amount increases.

  In addition, in the strict sense, if the spread angle (coherence factor) of exposure light at each point in the irradiation area is regarded as one of the illumination conditions when the transmittance or reflectance of the reticle pattern area is uniform, the irradiation area in a strict sense. The lighting conditions are different for each point. Therefore, when the slit width of the irradiation region is partially adjusted to control the exposure amount, the average illumination condition in the irradiation region may change.

  SUMMARY OF THE INVENTION In view of such circumstances, an object of the present invention is to make it possible to control the exposure amount on a substrate by reducing unevenness in exposure amount or variation in illumination conditions when scanning exposure of a substrate in an irradiation region.

  According to the first aspect of the present invention, when the substrate is moved in the first direction and the substrate is exposed to the irradiation region irradiated with the exposure light via the optical system, the exposure to the substrate is performed. In the exposure amount control method for controlling the exposure amount of light, the step of measuring the light intensity distribution of the irradiation region in the second direction intersecting with the first direction, and depending on the measurement result of the light intensity distribution, The step of adjusting the width of the irradiation region in the first direction for each of a plurality of positions in the second direction, and the plurality of positions in the second direction according to the width of the irradiation region in the first direction Adjusting the width of at least one end of the irradiation region where the light intensity of the exposure light gradually decreases with respect to the light intensity of the exposure light at the center of the irradiation region with respect to the first direction; Exposure amount control method including .

  According to the second aspect of the present invention, the substrate is exposed to the irradiation region of the projection optical system in the first direction while exposing the substrate with the exposure light through the mask and the projection optical system, and In an exposure method in which the substrate is exposed in synchronization with the movement of the mask in the direction corresponding to the first direction, the second direction intersecting the first direction using the exposure amount control method of the present invention. The width of the irradiation region in the first direction and the width of the irradiation region in the first direction at which the light intensity of the exposure light gradually decreases in each of the plurality of positions. An exposure method is provided in which the substrate is scanned and exposed in the adjusted irradiation region.

  Further, according to the third aspect of the present invention, the substrate is exposed to the irradiation region of the projection optical system in the first direction while exposing the substrate with the exposure light through the mask and the projection optical system, In an exposure method in which the substrate is exposed in synchronization with the movement of the mask in a direction corresponding to the first direction, the irradiation region of the irradiation region at each of a plurality of positions in the second direction intersecting the first direction. Adjusting the width in the first direction, and depending on the width in the first direction of the irradiated region after adjustment, for each of the plurality of positions in the second direction, the central portion of the irradiated region with respect to the first direction An exposure method for adjusting the width of at least one end of the irradiation region where the light intensity of the exposure light gradually decreases with respect to the light intensity of the exposure light in the step, and scanning and exposing the substrate in the adjusted irradiation region Is provided.

  According to a fourth aspect of the present invention, there is provided a device manufacturing method comprising: exposing a photosensitive substrate using the exposure method of the present invention; and processing the exposed photosensitive substrate. Is done.

  According to the present invention, the exposure amount on the substrate can be partially controlled by adjusting the width of the irradiation region in the first direction for each of a plurality of positions in the second direction. Further, by adjusting the width of the end portion where the light intensity of the exposure light in the irradiation region gradually decreases in accordance with the width in the first direction of the irradiation region for each of the plurality of positions, without changing the exposure amount. Further, unevenness in exposure amount or variation in illumination conditions can be reduced.

It is sectional drawing which shows schematic structure of the exposure apparatus of an example of embodiment. 1A is a plan view in which a part of the variable blind 35 in FIG. 1 is cut away, and FIG. 2B is a plan view of the variable blind 35 when the illumination area is rectangular. (A) is a perspective view which shows the principal part of the some blind unit 38 in FIG. 1, (B) is a side view which shows the rotation mechanism of FIG. 3 (A). (A) is sectional drawing which shows the blind unit 38, (B) is a figure which shows the state which rotated the blade 39 of FIG. 4 (A). (A) is a top view which shows the irradiation area | region 27W before adjustment of a slit width, (B) is a figure which shows an example of integrated exposure amount distribution after the scanning exposure by the irradiation area | region 27W. (A) is a plan view showing the irradiation region 27W after adjustment of the slit width, (B) is a diagram showing an example of the integrated exposure amount distribution after adjustment, (C) is Y of the irradiation region 27W in FIG. 6 (A). The figure which shows an example of the light intensity distribution of a direction, (D) is a figure which shows an example of the light intensity distribution of the Y direction of the irradiation area | region 27W after adjusting the width | variety of an intensity | strength inclination part. It is a flowchart which shows an example of exposure amount control operation | movement and exposure operation | movement. (A) is a plan view showing an example of a shot arrangement of a wafer, (B) is a diagram showing an example of setting a slit width of an irradiation region 27W in another example of the embodiment, and (C) is an irradiation of FIG. 8 (B). It is a figure which shows an example of the light intensity distribution of the Y direction of the area | region 27W. It is a flowchart which shows an example of the manufacturing process of an electronic device.

An example of an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 shows an exposure apparatus (EUV exposure apparatus) 100 that uses EUV light (Extreme Ultraviolet Light) such as 11 nm or 13 nm within a wavelength range of about 3 to 50 nm as exposure light EL (illumination light) of this embodiment. It is sectional drawing which shows the whole structure roughly. 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 the pattern formed on the pattern surface (reticle surface) of the reticle R onto the surface of the wafer W (substrate) coated with a photoresist (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 the wafer stage WST is placed, and within the plane perpendicular to the Z axis (substantially horizontal in this embodiment). The description will be made by taking the X axis perpendicular to the paper surface of FIG. 1 and the Y axis parallel to the paper surface of FIG. In this embodiment, the illumination optical system IL forms an elongated arc-shaped illumination area extending in the X direction on the reticle surface, 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 that is reflected by the curved mirror 24 is reflected by the concave mirror 25, and then ends in the −Y direction. However, it passes through the substantially arc-shaped edge portion of the blind plate 26 elongated in the X direction, and is formed into an arc shape. The exposure light EL shaped like an arc illuminates the pattern surface of the reticle R obliquely from below with a uniform illuminance distribution. Therefore, an arcuate illumination region 27R is formed on the pattern surface of the reticle R.

  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 reticle surface is partially shielded by the tips of the blades 39 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 irradiation area 27W (an area optically conjugate with the illumination area 27R) on the wafer W. In this case, a variable blind (variable field stop) 35 that defines the shape of the illumination region 27R and the shape of the irradiation region 27W when viewed from the projection optical system PO 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.

Further, at the start and end of scanning exposure of each shot area (die) on the wafer W, the irradiation area 27W is closed in the Y direction (scanning direction), and the width of the irradiation 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.
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. In addition to being driven with a predetermined stroke in the Y direction, it is also driven in minute amounts in the X direction and the θz direction (rotating direction around an axis parallel to 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 reticle surface side, an irradiation system that irradiates measurement light obliquely (eg, from the −X direction) to a plurality of positions in the illumination region 27R, and measurement light that is reflected obliquely (eg, in the + X direction) by the reticle R. An autofocus sensor (hereinafter referred to as a reticle AF system) 28 including a light receiving system for receiving light is disposed. The reticle AF system 28 measures the position in the Z direction at a plurality of locations in the illumination area 27 </ b> R within the reticle surface, and supplies the measured value to the main control system 31. The main control system 31 allows the position of the reticle surface in the Z direction (Z position) using, for example, a Z drive mechanism (not shown) in the reticle stage RST based on the measurement value of the reticle AF system 28 during scanning exposure. Set within the range. Further, for example, the main control system 31 is connected to the plurality of blind units 38 via the blind control system 33 so that the distance in the Z direction between the reticle surface and the tip of each blade 39 of the variable blind 35 is maintained within the set range. The rotation angle and the position of each blade 39 in the Z direction are controlled (details will be described later).

  As an example, the projection optical system PO is configured by holding six mirrors M1 to M6 with a lens barrel (not shown), non-telecentric on the object plane (reticle R) side, and on the image plane (wafer W) side. Telecentric reflection system. The projection magnification of the projection optical system PO 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 irradiation area 27W of the wafer W via the projection optical system PO.

  In the projection optical system PO, the exposure light EL reflected by the reticle surface is reflected upward (+ Z direction) by the mirror M1, subsequently reflected downward by the mirror M2, and then reflected upward by the mirror M3, and then by the mirror M4. Is 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 top of 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 large number 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. . As an example, the light receiving surface of the irradiation amount monitor 29 is set wider than the irradiation region 27W. The illuminance (or pulse energy) of the exposure light EL at each measurement position in the X direction of the irradiation region 27W can be measured by driving the wafer stage WST and moving the light receiving surface of the irradiation amount monitor 29 to the irradiation region 27W. Based on this measurement result, the main control system 31 illuminates with the variable blind 35 via the blind control system 33 so that the integrated exposure amount at each point of the wafer W scanned with respect to the irradiation area 27W becomes uniform. The width (slit width) in the Y direction of each position in the X direction of the region 27R (and thus the irradiation region 27W) is adjusted. Further, based on the adjusted slit width, the main control system 31 passes through the blind control system 33 so that the Z-direction interval (defocus amount) of each blade 39 with respect to the reticle surface becomes a predetermined value. The Z position of the blade 39 is adjusted (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 photoresist applied to the wafer W does not adversely affect the mirrors M1 to M6 of the projection optical system PO. 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 the wafer W, one shot area (die) of the wafer W is moved to the scanning start position by the step movement of the wafer stage WST in the X direction and the Y direction. Next, irradiation of the exposure light EL from the illumination optical system ILS to the reticle surface is started. Then, while exposing the irradiation area 27W on the surface of the wafer W with the image of the pattern in the illumination area 27R on the reticle surface by the projection optical system PO, the reticle R and the wafer W are exposed to the projection optical system PO. It moves synchronously in the Y direction at a speed ratio according to the projection magnification. Thus, the pattern image of the reticle R is scanned and exposed on the shot area of the wafer W. By repeating the step movement and the scanning exposure in this manner, a pattern image of the reticle R is sequentially exposed on a plurality of shot areas of 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.
FIG. 2A is a plan view in which a part of the variable blind 35 shown in FIG. 1 as viewed from the reticle R side is omitted. 2A, the shape of the edge portion 27Rb in the −Y direction of the arcuate illumination region 27R on the pattern surface of the reticle R is defined by the blind plate 26 in FIG. In addition, a plurality of blind units 38 are fixed in proximity to the X direction in a plurality of positions Pi (i = 1, 2,...) On the upper surface of the L-shaped rotary member 37. Blades 39 each having a tip portion that can be displaced in the Y direction and the Z direction are provided, and the tip portions of these blades 39 block the edge portion 27Ra in the + Y direction of the exposure light reflected from the illumination region 27R. In FIG. 2A, the plurality of blind units 38 on the −X direction side on the rotating member 37 are not shown.

As the number of blind units 38 (blades 39) increases, the shape of the illumination area 27R (and thus the irradiation area 27W on the surface of the wafer W) can be controlled with higher accuracy. The number of blind units 38 is, for example, about 10 to several tens.
In this case, since the edge portion 27Ra has an arc shape, the blades 39 of the plurality of blind units 38 are set so that the length in the Y direction is the shortest among the blades 39 at both ends (for example, the position P1), and is longer as the central blade 39. Has been. By controlling the position in the Y direction of the blade 39 of the blind unit 38 at the position Pi, the width hi in the Y direction of the illumination area 27R at the position Pi, and consequently the width in the Y direction (slit width) of the corresponding position of the irradiation area 27W. ) Can be controlled individually. For example, in the initial state, the shielding width in the Y direction of exposure light by the blades 39 of all the blind units 38 is set to be substantially the same (for example, the median value of the variable range), and the width hi of the illumination area 27R is also set to be substantially the same. ing.

  The rotating member 37 is formed with a plurality of positioning grooves 36a for positioning the bottom surface of the blind unit 38. Each blind unit 38 is placed on the corresponding positioning groove 36a and then bolted through the opening 36b. 50 (see FIG. 3A). The rotating member 37 is supported by a frame 36 so as to be rotatable around a rotating shaft 37 a parallel to the X axis, and one end of the rotating shaft 37 a can be rotated by a rotating motor 49 fixed to the frame 36. The frame 36 is supported on a side wall or the like of the vacuum chamber 1 of FIG. 1 via a connecting member (not shown), and the rotary motor 49 is controlled by the blind control system 33.

  As shown in FIG. 2B, the illumination optical system ILS may form, for example, a rectangular (rectangular) illumination region 27AR extending in the X direction on the reticle surface. In this case, the lengths of the blades 39 in the Y direction of the blind unit 38 at the respective positions Qi (i = 1, 2,...) On the rotating member 37 may be the same. In this configuration, by controlling the positions in the Y direction and the like of the blades 39 at a plurality of positions Qi, the width hi in the Y direction of the illumination region 27AR and the like are individually controlled.

  3A is a perspective view of a main part showing a support mechanism of the plurality of blind units 38 in the variable blind 35 of FIG. 2A, and FIG. 3B is a view of FIG. 3A in the + X direction. FIG. For convenience of explanation, in FIG. 3A, the shape of the blade 39 of the blind unit 38 is the same, but the shape of the blade 39 is actually different from each other. In FIG. 3A, the frame 36 of FIG. 3B is not shown.

  In FIG. 3A, the positions in the Y direction and Z direction of the tip of the blade 39 of each blind unit 38 can be controlled independently of each other, and each blind unit 38 is controlled by the blind control of FIG. It is connected to the system 33. Further, by rotating the rotary member 37 via the rotary motor 49, each blind unit 38 can be rotated integrally as shown in FIG. As a result, as indicated by the dotted line position 39B, the Z position of the edge portion at the tip of the blade 39 of each blind unit 38 can be adjusted in common by dZ. Such an operation is performed, for example, in order to maintain a constant distance between the reticle surface and the edge portion of the blade 39 when the Z position of the reticle surface measured by the reticle AF system 28 of FIG. Is called. Furthermore, in this embodiment, when the position of the edge portion of each blade 39 in the Y direction (the width of the corresponding irradiation region 27W in the Y direction) is adjusted, the uneven exposure amount due to the variation in the pulse energy of the exposure light EL. In order to reduce the Z, the Z position of the edge portion at the tip of the blade 39 is adjusted.

If the distance from the center of the rotation shaft 37a of the rotating member 37 to the edge portion of the blade 39 is L, and the Z position of the edge portion is changed by dZ, the position of the edge portion in the Y direction is approximately expressed by the following equation. It changes by dY.
dY = (L ² + dZ ² ) ^1/2 −L (1)
Therefore, when the Z position of the edge portion of the blade 39 is changed by dZ (approximately dZ / L (rad) converted into the tilt angle), the position of the blade 39 in the Y direction is maintained as it is. Therefore, the blind control system 33 moves the position of each blade 39 in the Y direction via the blind unit 38 by dY in Expression (1). Thereby, even when the blade 39 is uniformly inclined through the rotating member 37, the width of the illumination region 27R in the Y direction can be maintained constant.

The plurality of blind units 38 of the variable blind 35 in FIG. 3A have the same configuration except for the shape of the blade 39. Therefore, the configuration of one blind unit 38 will be typically described.
FIG. 4A is a diagram in which a part of the blind unit 38 is cut away. 4A, the blind unit 38 is attached to the front surface of the box-shaped member 40 with high pressure resistance and a predetermined range in the Y direction (a range including the movement stroke of the blade 39 in the Y direction). A flexible diaphragm 41 and a blade 39 fixed to the center of the diaphragm 41. The box-shaped member 40 and the diaphragm 41 are made of a metal with little degassing such as stainless steel. Further, a magnetic core member 39e is fixed to the end of the shaft portion 39a of the blade 39 in the box-shaped member 40, and the first and second core members 53A and 53B are sandwiched between the shaft portion 39a in the Z direction. The coils 52A and 52B are wound around the core members 53A and 53B, and a drive current is individually supplied to the coils 52A and 52B from the blind control system 33 via the signal cable CA. In addition, lower ends 39f and 39c are fixed to the bottom surface of the core member 39e so as to face the core members 53A and 53B, and the gap between the lower ends 39f and 39c is individually measured on the bottom surface of the box-shaped member 40. Capacitance sensors 43A and 43B are fixed. Further, the core member 39e is urged toward the bottom surface side of the box-shaped member 40 by the tension coil springs 55A, 55B fixed to the bottom surface of the box-shaped member 40 so as to face the core members 53A, 53B.

The blade 39 includes a rod-shaped shaft portion 39a driven by the coils 52A and 52B and the core members 53A and 53B (drive portion), and a stable + Y from the diaphragm 41 to the shaft portion 39a on the −Y direction side of the shaft portion 39a. The step part 39d for transmitting the urging | biasing force to a direction and the flat plate part 39b fixed to the front-end | tip of the -Y direction of the axial part 39a are included. Since the flat plate portion 39b is directly irradiated with EUV light, the flat plate portion 39b is formed of a high heat resistant ceramic such as zirconia, or a high heat resistant metal such as beryllium (Be) or chromium-molybdenum steel. The shaft part 39a and the step part 39d of the blade 39 are made of metal having high thermal conductivity.

  Further, the space between the box-shaped member 40 and the diaphragm 41 is sealed by the welded portion 41a, the space between the diaphragm 41 and the blade 39 is sealed by the welded portion 41b, and the inside of the box-shaped member 40 is hermetically sealed. . In the present embodiment, the outside of the box-shaped member 40 is set to a high vacuum in order to transmit EUV light, and the inside of the box-shaped member 40 is at almost atmospheric pressure. An air supply port and an exhaust port are provided on the bottom surface of the box-shaped member 40. In addition, a blower 47A for blowing a gas (refrigerant) such as cooled air and a suction unit 47B for sucking (collecting) the gas are disposed outside the vacuum chamber 1 in FIG. The cooled gas is supplied into the box-shaped member 40 through the pipe 48A and the air supply port, and the gas flowing through the box-shaped member 40 is collected by the suction unit 47B through the exhaust port and the pipe 48B. The blowing unit 47A and the suction unit 47B are controlled by the blind control system 33.

The detection results of the capacitance sensors 43A and 43B are supplied to the blind control system 33. From the detection result, the blind control system 33 can recognize the position in the Y direction and the Z direction of the edge portion of the blade 39 (the tip of the flat plate portion 39b of the blade 39).
According to the blind unit 38, the suction force between the core members 53A and 53B and the core member 39e can be independently controlled by controlling the current supplied to the coils 52A and 52B. Therefore, by controlling the two suction forces in common, the position of the blade 39 in the Y direction can be controlled. Further, by making the two suction forces different from each other, the blade 39 can be rotated around the center fulcrum B7 of the diaphragm 41, for example, as indicated by a dotted position B6 in FIG. As a result, the Z position of the edge portion of the blade 39 can be controlled by ΔZ.

However, when the position of the edge portion of the blade 39 in the Y direction is changed by rotating the blade 39, the position of the blade 39 in the Y direction may be adjusted so as to cancel the change in the position.
Thus, in this embodiment, since the position of the edge part of each braid | blade 39 in the Z direction can be adjusted, you may abbreviate | omit the mechanism containing the rotation member 37 which rotates all the blind units 38 simultaneously.

Next, an example of the exposure amount control operation and the exposure operation of the exposure apparatus 100 of the present embodiment will be described with reference to the flowchart of FIG. This operation is controlled by the main control system 31 and the blind control system 33.
First, in step 102 of FIG. 7, a measurement reticle (not shown) having a uniform high reflectance pattern region is loaded on the reticle stage RST of FIG. 1, the reticle stage RST is driven, and the illumination region 27R is driven. An area where the reflectance of the measurement reticle is high is arranged in the area. In the next step 104, the blind control system 33 sets the positions in the Y direction and Z direction of the edge portions of the blades 39 of all the blind units 38 of the variable blind 35 to the median value of the variable range. As a result, the slit width of the irradiation region 27W at each position in the X direction is set to the median value of the variable range.

  In the next step 106, wafer stage WST is driven to move the light receiving surface of irradiation amount monitor 29 to irradiation area 27W on the image plane of projection optical system PO, and exposure light EL having a predetermined number of pulses is emitted from illumination optical system ILS. The illumination area 27R of the measurement reticle is irradiated. In this state, the irradiation intensity monitor 29 measures the light intensity distribution of the exposure light EL over the entire irradiation area 27 </ b> W, and supplies the measurement result to the main control system 31.

For convenience of explanation, as shown in FIG. 5A, it is assumed that the arrangement direction of the irradiation region 27W is the same as that of the illumination region 27R in FIG. Therefore, the edge portion 62A in the −Y direction of the irradiation region 27W is defined by the edge portion of the blind plate 26 in FIG. 1, and the shape of the edge portion 62B in the + Y direction of the irradiation region 27W is in the X direction in FIG. It is defined by the edge portions of the image 39P of the blade 39 of the blind unit 38 at a plurality of positions Pi (i = 1 to I; I is an integer of 2 or more). The edge part 62B can be extended to the edge part 61 in the + Y direction indicated by the dotted line.

Further, the average value of the slit width (width in the Y direction) of the irradiation area 27W defined by the image 39P of the blade 39 at each position Pi is set as the slit width at the position of the X coordinate Xi at the center of the image 39P. The slit width at each position Xi in the X direction of the irradiation region 27W in FIG. 5A is the median value H0.
Furthermore, the distribution of the light intensity Ei of the irradiation region 27W on the straight line having the X coordinate Xi is a trapezoidal light intensity distribution 64 of FIG. The slit width (here, H0) of the light intensity distribution 64 is defined by the interval in the Y direction between two points where the light intensity in the light intensity distribution 64 is the median between the maximum value and the minimum value. . Also, in the vicinity of the edge portions in the −Y direction and the + Y direction of the light intensity distribution 64, the light intensity Ei gradually decreases from the maximum value to the minimum value, and the intensity inclined portions 64A and 64B (of the irradiation region 27W). The width of the end portion in the Y direction is YA. The width YA of the intensity inclined portions 64A and 64B is determined according to the defocus amount from the reticle surface of the edge portions of the blind plate 26 and the blade 39. In the present embodiment, since the blind plate 26 is fixed, the width YA of the strength inclined portion 64A is constant.

Furthermore, when the length in the Y direction from the edge portion in the −Y direction of the intensity inclined portion 64A to the edge portion in the + Y direction of the intensity inclined portion 64B is the total length HY0 in the Y direction of the light intensity distribution 64 (irradiation region 27W), The total length HY0 is as follows.
HY0 = H0 + YA / 2 + YA / 2 = H0 + YA (2)
Further, since the exposure light EL of the present embodiment is pulse light, if the distance that the wafer stage WST (wafer W) moves in the Y direction during pulse emission during scanning exposure is ΔY in FIG. The number of exposure pulses N0 with respect to the point of the position Xi in the X direction of the wafer W by the irradiation region 27W is approximately as follows.

N0≈HY0 / ΔY (3)
In addition, since the exposure light EL has energy variations for each pulse emission, if the number of exposure pulses N0 is small, there is a risk that uneven exposure will occur. Therefore, the total length HY0 and the distance ΔY of the irradiation region 27W are set so that the number of exposure pulses N0 is equal to or greater than the predetermined reference value Nmin and the uneven exposure amount is within the allowable range. Note that the distance ΔY that wafer stage WST moves during pulsed emission is determined based on scanning speed VW of wafer stage WST and the emission frequency of exposure light EL. It should be noted that the intensity gradient portions 64A and 64B of the light intensity distribution 64 have an accumulated exposure amount of 1 to 2 pulses of pulse energy at each point of the wafer W due to slight variations in the timing of pulse emission of the exposure light EL. It is provided so that variations do not occur.

  In the next step 108, in the calculation unit of the main control system 31, the image of the blade 39 at the position Pi (i = 1 to I) in FIG. An integrated exposure amount ΣEi is obtained by integrating the light intensities in the shaded areas 63i having the same width as 39P. As shown in FIG. 5B, the integrated exposure amount ΣEi is obtained for each of a plurality of positions Xi in the X direction (non-scanning direction).

In the next step 110, in the calculation unit of the main control system 31, for example, a range having a predetermined width with respect to the obtained average value of the integrated exposure amounts ΣEi is set as the allowable range AE. Then, among the plurality of positions Xi, a position Xk where the integrated exposure amount ΣEi is larger than the allowable range AE and a position Xj where the integrated exposure amount ΣEi is larger than the allowable range AE are specified.
The amount of adjustment of the position in the Y direction of the corresponding blade 39 is determined so that the slit width of the irradiation area 27W becomes narrower, and at the position Xj where the integrated exposure amount ΣEi is smaller than the allowable range AE, the slit width of the irradiation region 27W is increased. The amount of adjustment of the position of the blade 39 in the Y direction is obtained, and information on the obtained amount of adjustment of the position in the Y direction is supplied to the blind control system 33. In response to this, the blind control system 33 adjusts the position of each blade 39 of the variable blind 35 in the Y direction.

  As a result, the irradiation area 27W by the adjusted projection optical system PO is set so that the edge portion 62C in the + Y direction changes stepwise as shown in FIG. 6A, and the image of the blade 39 at the position Pi. The slit width Hi of the irradiation region 27W defined by 39P can be a value different from the median value H0. Further, as shown in FIG. 6B, each slit width Hi is adjusted so that the total accumulated exposure amount ΣEi for each of the plurality of positions Xi in the X direction falls within the allowable range AE.

In this case, if the adjusted slit width Hi of the irradiation region 27W at the position Xi is narrower than the initial median value H0, the width in the Y direction of the intensity gradient portions 65A and 65B at both ends of the light intensity distribution 65 at the position Xi. Since YA is the same as the width before adjustment, the total length HY in the Y direction of the light intensity distribution 65 (adjusted irradiation region 27W) becomes narrower than the total length HY0 before adjustment as follows.
HY = Hi + YA <HY0 (4)
Therefore, the exposure pulse number N at the position Xi of the wafer W after the scanning exposure in the irradiation region 27W after adjusting the slit width is substantially equal to or less than the exposure pulse number N0 of the equation (3) as follows.

N≈HY / ΔY <HY0 / ΔY≈N0 (5)
Therefore, in the next step 112, the blind control system 33 determines that the total length HY of the irradiation region 27W becomes HY0 at the position Xi where the adjusted total length HY of the irradiation region 27W is narrower than the median value H0, for example, ΔY or more. As described above, the position of the edge portion of the corresponding blade 39 in the Z direction is adjusted in a direction away from the reticle surface. That is, the defocus amount at the edge portion is increased. In the light intensity distribution 66 of the irradiation region 27W after the adjustment, the width YB of the intensity inclined portion 66B in the + Y direction becomes wide as shown in FIG. Since the slit width of the light intensity distribution 66 is Hi and the width of the other intensity gradient portion 66A is YA, the following relationship is established.

YA / 2 + Hi + YB / 2 = HY0 (6)
Therefore, from the expressions (2) and (6), the position in the Z direction of the edge portion of the corresponding blade 39 may be adjusted so that the width YB of the intensity inclined portion 66B becomes the following value.
YB = 2 (H0-Hi) + YA (7)
Since the projection optical system PO in FIG. 1 is non-telecentric on the reticle side, when the Z position of the edge portion of the blade 39 is adjusted, more precisely, the edge portion is on the object plane side of the projection optical system PO. It is preferable to move parallel to the optical axis.

  When the entire length of the irradiation region 27W is set to HY0 in this way, the number of exposure pulses at the position Xi of the wafer W after scanning exposure is N0. Therefore, even if the exposure light EL has a variation in energy for each pulse emission, The unevenness of the exposure amount does not increase. Furthermore, since the slit width of the irradiation region 27W (light intensity distribution 66) remains Hi, the integrated exposure amount ΣEi is within the allowable range.

  Since the integrated exposure amount ΣEi is smaller than the allowable range AE, the number of exposure pulses becomes N0 or more at the position where the slit width Hi of the irradiation region 27W is widened. There is no need to adjust. With the above operation, the setting of the slit width Hi at each position Xi in the X direction of the irradiation region 27W and the width YB of the intensity inclined portion 66B in the + Y direction of the irradiation region 27W is completed.

In the next step 114, the reticle R is applied to the reticle stage RST of the exposure apparatus 100.
And align reticle R using an alignment system (not shown). In the next step 116, an unexposed wafer W coated with a photoresist is loaded onto wafer stage WST, and alignment is performed using an alignment system (not shown). In the next step 118, the reticle R and the wafer W are projected while stepping the wafer W and exposing the image of the pattern in the illumination area 27R of the reticle R to the irradiation area 27W of the wafer W via the projection optical system PO. The operation of moving in synchronization with the optical system PO in the Y direction is repeated to scan and expose a plurality of shot areas of the wafer W with the irradiation area 27W. The exposed wafer W is unloaded. In the next step 120, when there is an unexposed wafer, steps 116 and 118 are repeated.

According to the present embodiment, the image of the pattern of the reticle R can be exposed to the entire surface of the plurality of shot areas of the wafer W with an appropriate integrated exposure amount and with a small uneven exposure amount.
The effects and the like of this embodiment are as follows.
(1) In the exposure amount control method by the exposure apparatus 100 of this embodiment, the wafer W is moved in the Y direction (first direction) with respect to the irradiation region 27W irradiated with the exposure light EL via the projection optical system PO (optical system). The exposure amount of the exposure light EL for the wafer W is controlled when the wafer W is exposed by moving in the direction). The exposure amount control method includes steps 106 and 108 for measuring the light intensity distribution of the irradiation region 27W in the X direction (second direction) orthogonal to the Y direction, and the X direction in accordance with the measurement result of the light intensity distribution. Irradiation is performed in the Y direction for each of the plurality of positions Xi in the X direction according to the step 110 for adjusting the width (slit width) in the Y direction of the irradiation region 27W for each of the plurality of positions Xi and the adjusted slit width Hi. Step 112 of adjusting the width YA of one intensity inclined portion 65B (end) of the irradiation region 27W where the light intensity of the exposure light EL gradually decreases with respect to the light intensity of the exposure light EL in the central portion of the region 27W to the width YB. Including.

  According to this embodiment, by adjusting the slit width of the irradiation region 27W for each of a plurality of positions in the X direction, the integrated exposure amount after scanning exposure on the wafer W can be controlled to an appropriate exposure amount. Further, the width of the intensity inclined portion 65B of the irradiation region 27W is adjusted so that the total length in the Y direction of the irradiation region 27W becomes the total length before adjustment according to the slit width of the irradiation region 27W for each of the plurality of positions. Thus, even when the exposure light EL is pulsed light without changing the integrated exposure amount, the uneven exposure amount can be reduced.

In the present embodiment, the width of one intensity inclined portion 65B of the irradiation region 27W is adjusted, but the width in the Y direction of both intensity inclined portions 65A and 65B of the irradiation region 27W may be adjusted.
(2) Further, the irradiation region 27W is defocused from the reticle surface optically conjugate with respect to the surface of the wafer W and the projection optical system PO, and independently from each other in the Y direction (direction corresponding to the Y direction of the irradiation region 27W). Is set by a variable blind 35 having a plurality of blades 39 (light shielding members) arranged in the X direction (direction corresponding to the X direction of the irradiation region 27W). In step 110, the positions of the plurality of blades 39 in the Y direction are individually adjusted. In step 112, the defocus amounts of the edge portions of the plurality of blades 39 from the reticle surface are individually adjusted. Therefore, the width in the Y direction of the intensity inclined portion 65B of the irradiation region 27W can be easily adjusted.

(3) The exposure light EL is pulsed light, and in step 112, the width of the intensity gradient portion 65B is adjusted so that the number of exposure pulses for each point of the wafer W irradiated in the irradiation region 27W is substantially constant. The As a result, even if the pulse energy of the exposure light EL varies, the uneven exposure amount is reduced.
(4) In the exposure method by the exposure apparatus 100, the wafer W is exposed to the irradiation area 27W of the projection optical system PO in the Y direction while exposing the wafer W with the exposure light EL via the reticle R and the projection optical system PO. In the exposure method in which the movement and the movement of the reticle R in the direction corresponding to the Y direction are performed in synchronization to expose the wafer W, the exposure amount control method of the present embodiment is used for each of a plurality of positions in the X direction. Steps 106 to 112 for adjusting the slit width of the irradiation region 27W and the width in the Y direction of one intensity inclined portion 65B of the irradiation region 27W, and step 118 for scanning and exposing the wafer W with the adjusted irradiation region 27W, Have

Therefore, the entire surface of each shot area of the wafer W can be exposed with an appropriate integrated exposure amount and with a small uneven exposure amount. Also in this exposure method, the widths of both intensity inclined portions 65A and 65B in the irradiation region 27W may be adjusted.
In the present embodiment, the width of the intensity gradient portion 65B of the irradiation region 27W is adjusted so that the number of exposure pulses for the wafer W is substantially constant. However, for example, when the variation of the pulse energy is small, the adjustment of the width of the intensity inclined portion 65B (or 65A, 65B) of the irradiation region 27W in step 112 is performed for the irradiation region 27W for each of a plurality of positions in the X direction. You may carry out so that illumination conditions may become substantially constant.

  In this case, the edge portion of each blade 39 of the variable blind 35 is defocused from the reticle surface, and as the defocus amount increases, the opening angle of the exposure light EL in the irradiation region 27W (substantially the coherence of the exposure light EL). (Corresponding to the factor (σ value)) becomes smaller. Therefore, when the variation of the σ value of the exposure light EL irradiated from the illumination optical system ILS to the illumination area 27R (and hence the irradiation area 27W) is known in advance, the slit width of the irradiation area 27W is set at step 110. After the adjustment, when the σ value decreases on average at the position Xi at which the slit width is adjusted, the defocus amount at the edge portion of the blade 39 is reduced (the width of the intensity inclined portion 65B is reduced) instead of step 112. ) May be increased. In addition, after adjusting the slit width of the irradiation region 27W, when the σ value is increased on average at the position Xi where the slit width is adjusted, the defocus amount of the edge portion of the blade 39 is increased instead of step 112. The σ value may be reduced (by increasing the width of the strength inclined portion 65B). Thereby, after adjusting the slit width of the irradiation region 27W, the σ value (illumination condition) can be kept constant at each position in the X direction.

Next, another example of the embodiment of the present invention will be described with reference to FIGS. 8 (A) to 8 (C). Also in this embodiment, the exposure apparatus 100 provided with the variable blind 35 of FIG. 1 is used. Hereinafter, in FIGS. 8A, 8B, and 8C, portions corresponding to those in FIGS. 6A and 6D are denoted by the same reference numerals, and detailed description thereof is omitted. To do.
In this embodiment, it is assumed that the slit width at each position in the X direction of the irradiation region 27W is set in advance so that the integrated exposure amount after scanning exposure becomes a predetermined target value ΣEa. The set value of the slit width is H0. The target value ΣEa of the integrated exposure amount is an appropriate exposure amount when the thickness of the photoresist applied to the wafer W is a predetermined specified value d0.

  As shown in FIG. 8A, the surface of the wafer W exposed in the present embodiment has a plurality of shot areas SAi (i = 1 to N; N is a predetermined interval in the X direction and the Y direction (scanning direction). An integer of 2 or more). In this embodiment, before the exposure of the wafer W, the thickness distribution of the photoresist applied to the surface of the wafer W in advance by a film thickness inspection apparatus (not shown) is measured. As a result of the measurement, for example, the average thickness dp in the region 68A at the end in the + X direction of the shot region SAi is thicker than d0, the average thickness in the central region 68B is approximately d0, and It is assumed that the average thickness dm in the end region 68C is thinner than d0. In this case, the integrated exposure amount in the area 68A of the shot area SAi is preferably larger than the target value ΣEa, and the integrated exposure amount in the area 68C is preferably smaller than the target value ΣEa.

Therefore, when the shot area SAi of the wafer W is moved in the + Y direction, for example, with respect to the irradiation area 27W to scan and expose the shot area SAi, the position of each blade 39 of the variable blind 35 in FIG. As shown in FIG. 8B, the regions 68A and 68B
, And 68C, the slit widths are set to Hp, H0 wider than H0, and Hm narrower than H0, respectively. The adjusted slit widths Hp and Hm are set so that the integrated exposure amount after scanning exposure is an appropriate exposure amount for photoresists of thickness dp and dm, respectively.

  Further, the light intensity distribution 69 at the position of the slit width Hm (the position of the image 39P of the blade 39 corresponding to the position Pm) in the region 68C of the irradiation region 27W is the Y direction as shown by the dotted line in FIG. The total length HY is narrower than the full length HY0 of the light intensity distribution 64 having the slit width H0. Therefore, the number of exposure pulses in the region 68C decreases as it is, and the exposure amount unevenness due to the variation in pulse energy increases. Therefore, in order to reduce the unevenness of the exposure amount, the defocus amount with respect to the reticle surface of the edge portion of the blade 39 at the corresponding position Pm is increased, and the light intensity distribution 69 in FIG. Adjust to 71. The width YA of the intensity gradient portion 71A in the -Y direction of the light intensity distribution 71 is the same, and the width YC of the intensity gradient portion 71B in the + Y direction is set so that the total length of the light intensity distribution 71 is HY0. Then, the shot area SAi of the wafer W is scanned and exposed by the irradiation area 27W having the light intensity distribution 71 in the area 68C.

Similarly, in the other shot areas SAi, the slit width and the intensity gradient portion of the irradiation area 27W can be exposed with an appropriate exposure amount according to the thickness of the photoresist, and the uneven exposure amount can be suppressed. The width is adjusted.
In the exposure method of the present embodiment, the wafer W (substrate) is exposed to the irradiation area 27W of the projection optical system PO while exposing the wafer W (substrate) with the exposure light EL via the reticle R and the projection optical system PO. ) And the movement of the reticle R in the direction corresponding to the Y direction are performed in synchronization with each other to expose the wafer W. In this exposure method, the slit width (width in the Y direction) of the irradiation region 27W is adjusted for each of a plurality of positions related to the X direction orthogonal to the Y direction, and the X direction is related to the adjusted slit width. For each of a plurality of positions, a step of adjusting the width of one intensity inclined portion of the irradiation region 27W with respect to the Y direction and a step of scanning and exposing the wafer W in the adjusted irradiation region 27W are included.

  Further, the adjustment of the slit width of the irradiation region 27W is performed according to the uneven application of the photoresist on the wafer W. Therefore, even if there is uneven application of photoresist on the surface of the wafer W, the entire surface of each shot area SAi of the wafer W can be exposed with a substantially appropriate exposure amount, and uneven exposure amount due to variations in pulse energy can be reduced. In this case as well, the width of the intensity gradient portion on both sides of the irradiation region 27W may be adjusted.

In the above embodiments, the following modifications are possible.
(1) In FIG. 1, the blind plate 26 and the variable blind 35 are arranged in the vicinity of the reticle surface. However, a conjugate surface with the reticle surface is formed in the illumination optical system ILS, and at least the blind plate 26 and the variable blind 35 are arranged. One may be arranged in the vicinity of a conjugate plane with the reticle surface. In addition, the variable blind 35 may be disposed between the projection optical system PO and the wafer W, for example.

  (2) The blind unit 38 of FIG. 4 (A) drives the blade 39 with two degrees of freedom by a drive unit including two coils 52A and 52B. In addition, the blade 39 may be driven by a drive unit that combines, for example, a first slide mechanism that moves in the Y direction and a second slide mechanism that moves in the Z direction. When this drive unit is used, the position of the edge portion of the blade 39 in the Z direction can be adjusted by moving the blade 39 in parallel.

(3) In the above-described embodiment, the inside of the box-shaped member 40 of the blind unit 38 is set to atmospheric pressure, but the inside of the box-shaped member 40 may be evacuated. For example, the pressure of the box-shaped member 40 can be the same as that in the vacuum chamber 1. In this case, the temperature of the box-shaped member 40 may be adjusted by fixing a Peltier element to the side surface of the box-shaped member 40.
Further, when an electronic device (or microdevice) such as a semiconductor device is manufactured using the exposure method of the exposure apparatus (EUV exposure apparatus) of the above embodiment, the electronic device is an electronic device as shown in FIG. Step 221 for performing functional / performance design, 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, and the embodiment described above A substrate processing step 224 including a step of exposing a mask pattern to a substrate (photosensitive substrate) by the exposure method, a step of developing the exposed substrate, a heating (curing) and etching step of the developed substrate, and a device assembly step ( (Including processing processes such as dicing, bonding, and packaging) And an inspection step 226, and the like.

  In other words, the device manufacturing method includes exposing the photosensitive substrate (wafer) using the exposure method of the above-described embodiment, and processing the exposed photosensitive substrate (step 224). Yes. At this time, according to the exposure apparatus of the above embodiment, the integrated exposure amount for each point of the substrate can be controlled to an appropriate value with high accuracy, and the uneven exposure amount due to variations in pulse energy can be reduced. Electronic devices can be manufactured with high accuracy.

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 illumination area may be set on the reticle of the transmissive type by installing the variable blind 35 in the arrangement as shown in FIG.

  In addition, this invention is not limited to the above-mentioned embodiment, Of course, a various structure can be taken in the range which does not deviate from the summary of this invention.

  ILS ... illumination optical system, R ... reticle, PO ... projection optical system, W ... wafer, 26 ... blind plate, 27R ... illumination area, 27W ... irradiation area, 28 ... reticle AF system, 29 ... irradiation dose monitor, 33 ... blind Control system, 35 ... variable blind, 38 ... blind unit, 39 ... blade

Claims (9)

An exposure amount control method for controlling an exposure amount of the exposure light to the substrate when the substrate is exposed in the first direction with respect to an irradiation region irradiated with the exposure light via the optical system In
Measuring a light intensity distribution of the irradiation region with respect to a second direction intersecting the first direction;
Adjusting the width of the irradiation region in the first direction for each of a plurality of positions in the second direction according to the measurement result of the light intensity distribution;
Depending on the width of the irradiation region in the first direction, the exposure is performed with respect to the light intensity of the exposure light in the central portion of the irradiation region with respect to the first direction for each of the plurality of positions with respect to the second direction. Adjusting the width of at least one end of the irradiated region where the light intensity of light gradually decreases; and
An exposure amount control method comprising: The irradiation region is defocused from an optically conjugate plane with respect to the surface of the substrate and the optical system, and the position in the direction corresponding to the first direction is variable independently of each other. Is set by a variable blind having a plurality of light shielding members arranged in a direction corresponding to
The step of adjusting the width of the irradiation region in the first direction individually adjusts the position of the plurality of light shielding members in the direction corresponding to the first direction,
2. The exposure amount according to claim 1, wherein the step of adjusting the width of the end portion individually adjusts a defocus amount from the optically conjugate surface of the edge portions of the plurality of light shielding members. Control method. The exposure light is pulsed light,
3. The step of adjusting the width of the end portion is performed so that the number of exposure pulses for each point of the substrate irradiated in the irradiation region is substantially constant. Exposure amount control method.   The exposure amount control method according to claim 1, wherein the step of adjusting the width of the end portion is performed such that illumination conditions of the irradiation region are substantially constant with respect to the second direction. . While exposing the substrate with exposure light through the mask and the projection optical system, the substrate moves in the first direction relative to the irradiation area of the projection optical system, and the mask moves in the direction corresponding to the first direction. In the exposure method of exposing the substrate in synchronization with,
The width of the irradiation region in the first direction for each of a plurality of positions in the second direction intersecting the first direction using the exposure amount control method according to any one of claims 1 to 4. And adjusting the width in the first direction of at least one end of the first direction in which the light intensity of the exposure light in the irradiation region gradually decreases,
Scanning and exposing the substrate in the adjusted irradiation region;
An exposure method characterized by the above. While exposing the substrate with exposure light through the mask and the projection optical system, the substrate moves in the first direction relative to the irradiation area of the projection optical system, and the mask moves in the direction corresponding to the first direction. In the exposure method of exposing the substrate in synchronization with,
Adjusting the width of the irradiation region in the first direction for each of a plurality of positions related to the second direction intersecting the first direction;
According to the width of the irradiation region in the first direction after adjustment, the light intensity of the exposure light at the central portion of the irradiation region with respect to the first direction for each of the plurality of positions with respect to the second direction. Adjusting the width of at least one end of the irradiation region where the light intensity of the exposure light gradually decreases,
Scanning exposure of the substrate in the irradiated area after adjustment;
An exposure method characterized by the above. The irradiation area is defocused from an optically conjugate plane with respect to the surface of the substrate and the projection optical system, and the position in the direction corresponding to the first direction is variable independently of each other. Set by a variable blind having a plurality of light blocking members arranged in a direction corresponding to the direction,
In order to adjust the width of the irradiation region in the first direction, individually adjust the position of the plurality of light shielding members in the direction corresponding to the first direction,
7. The defocus amount from the optically conjugate surface of the edge portions of the plurality of light shielding members is individually adjusted in order to adjust the width of the end portion of the irradiation region. The exposure method as described.   The exposure method according to claim 6 or 7, wherein the adjustment of the width of the irradiation region in the first direction is performed according to uneven application of the photosensitive material on the surface of the substrate. Exposing the photosensitive substrate using the exposure method according to any one of claims 5 to 8,
Processing the exposed photosensitive substrate.

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