JP2006250587A - Measuring device, drive unit and manufacturing method thereof, optical unit, optical device, and exposing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely measure the position relationship between inner and outer rings. <P>SOLUTION: First/second sensor heads and first/second scale sections adjusted in an adjustment process (step 210) are fixed in a fixing process (step 212), and the scale section of each sensor is connected to an inner ring while they are being fixed, and each sensor head is connected to an outer ring (step 214). Then, in a releasing process (step 216), the fixation of the scale section and the sensor head is released, thus dispensing with the adjustment of the position posture relationship between the measuring axes of each sensor after mounting. The position posture relationship between measuring axes is adjusted before mounting, thus adjusting and setting the position posture relationship precisely. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a measurement apparatus, a drive unit and a manufacturing method thereof, an optical unit, an optical apparatus, and an exposure apparatus. More specifically, the first object and the second object are different including the first axis direction and the second axis direction. The present invention relates to a measurement apparatus that measures relative position information in a plurality of directions, a drive unit including the measurement apparatus and a manufacturing method thereof, an optical unit including the drive unit, an optical apparatus including the optical unit, and an exposure apparatus including the optical apparatus.

  Conventionally, in a lithography process for manufacturing a semiconductor element, a liquid crystal display element or the like, a resist or the like is applied to a pattern formed on a mask or a reticle (hereinafter, collectively referred to as “reticle”) via a projection optical system. In addition, an exposure apparatus is used that transfers onto a substrate such as a wafer or glass plate (hereinafter also referred to as “wafer” as appropriate). In recent years, as this type of apparatus, a step-and-repeat type reduction projection exposure apparatus (so-called “stepper”), a step-and-scan type scanning type improved from this stepper, from the viewpoint of emphasizing throughput. A sequential movement type projection exposure apparatus such as an exposure apparatus is mainly used.

  In such an exposure apparatus, conventionally, an ultraviolet ray from an ultra-high pressure mercury lamp, for example, i-line (wavelength 365 nm), KrF excimer laser light (wavelength 248 nm), or the like is used as illumination light (exposure beam) for exposure. It was. In recent years, in order to obtain a higher resolution (resolution), an exposure apparatus using an ArF excimer laser beam (wavelength 193 nm) as an exposure beam has been put into practical use. As a projection optical system of these exposure apparatuses, a refraction system consisting only of a refractive optical element (lens) has been mainly used.

  On the other hand, in order to manufacture a finer semiconductor element or the like, recently, an EUV exposure apparatus that uses light in a soft X-ray region having a wavelength of about 100 nm or less, that is, EUV (Extreme Ultraviolet) light, as an exposure beam. Development is also underway. In this EUV exposure apparatus, since there is no optical material that transmits EUV light at the present time, the illumination optical system and the projection optical system are all constituted by reflective optical elements (mirrors), and the reticle is also a reflective reticle.

  By the way, in order to transfer the image of the reticle pattern onto the wafer with high resolution, regardless of whether the refraction system, the catadioptric system, or the reflection system is used as the projection optical system, the imaging characteristics of the projection optical system ( It is necessary to adjust various aberrations, and means for adjusting the position and orientation of at least a part of optical members (hereinafter referred to as “movable optical members”) constituting the projection optical system (hereinafter referred to as “movable optical members”). Generally referred to as “position and orientation adjustment means”). As this position and orientation adjustment means, for example, one using a parallel link type adjustment mechanism employing a parallel link mechanism is known. Further, the position of the movable optical member may be measured using an interferometer, for example.

  However, when the position of the movable optical member is measured using an interferometer, the interferometer does not have an absolute origin and detects a change in distance from the point of reset. There is an inconvenience that the previous position is not known. Further, when using an interferometer, the position of the movable optical member is usually measured on a three-dimensional orthogonal coordinate system of X, Y, and Z. Therefore, when using a drive mechanism such as the parallel link described above, When calculating the drive amount of each link from the measurement value of the interferometer, a complicated coordinate conversion operation or the like is required.

  Further, in the position and orientation measurement of the movable optical member in the adjustment mechanism used in the conventional projection optical system, adjustment of the origin position of the position and orientation measurement system and adjustment of the relative positional relationship of each measurement axis are not particularly considered. The position and orientation relationship between the measurement axes was ensured only with the mounting accuracy of the measurement device.

  However, when the origin position of the position / orientation measurement system is not adjusted, the origin position is adjusted by adjusting the adjustment mechanism, so that the stroke of the adjustment mechanism for adjusting the position / orientation of the movable optical member is reduced. . In particular, when a drive mechanism composed of a parallel link with a short stroke is used, there is a possibility that the use stroke becomes too short and the position and orientation of the movable optical member itself cannot be adjusted. In addition, it has been difficult to construct a highly accurate measurement system for the position / orientation relationship between the measurement axes only by ensuring the position / orientation relationship between the measurement axes only with the mounting accuracy of the measurement device as in the past. For these reasons, it has been difficult for the conventional measurement system to accurately measure and adjust the position and orientation of the movable optical member.

  The present invention has been made under the circumstances described above. From the first viewpoint, the relative positions of the first object and the second object in different directions including the first axis direction and the second axis direction are different. A measuring device for measuring information, wherein the detection target is connected to one of the first and second objects, and is connected to the other of the first and second objects. First and second sensors each including a sensor head that outputs a signal corresponding to a position as position information, and the measurement axes of the first and second sensors are the first axial direction and the second sensor, respectively. The measuring device is adjusted in advance in the axial direction.

  According to this, the measuring device is connected to the detection object connected to one of the first and second objects and the other of the first and second objects, and corresponds to the position of the detection object. Each including a sensor head that outputs a signal as position information, and each measurement axis includes first and second sensors that are adjusted in advance in the first axis direction and the second axis direction. It is not necessary to adjust the position and orientation relationship between the measurement axes of the first and second sensors constituting the measurement device after being attached to the two objects. In addition, since the position / orientation relationship between the measurement axes is adjusted before the measurement device is attached to the first and second objects, the position / orientation relationship can be adjusted and set with high accuracy. Therefore, the positional relationship between the first object and the second object can be measured with high accuracy by the measuring device.

  From a second viewpoint, the present invention is a method of manufacturing a drive unit that drives a first object relative to a second object, wherein the first object and the second object are assembled via a drive mechanism. An attachment step; a detection target connected to one of the first and second objects; and a detection target connected to the other of the first and second objects; An adjusting step for preliminarily adjusting respective measurement axes of the first and second sensors including respective sensor heads that output corresponding signals as position information; and each of the first and second sensors. A fixing step of fixing the detection object and the sensor head in the adjusted state; connecting the detection object of each sensor to the one object side; and connecting each sensor head to the other object side. Connection process to connect to the object side; It is a manufacturing method of a drive unit comprising; releasing step and of releasing the fixing of the detection object with the sensor head.

  According to this, the detection target connected to one of the first and second objects and the signal corresponding to the position of the detection target connected to the other of the first and second objects are transmitted to the position information. Each of the sensor heads, and each of the measurement axes includes the first and second sensors whose first and second sensors are adjusted in advance in the first and second axial directions. A drive unit for driving the second object with respect to the second object is manufactured. Therefore, the positional relationship between the first object and the second object can be measured with high accuracy by the measuring device, and the first object is driven with respect to the second object by the drive unit based on the measurement result. Thus, the positional relationship between the two can be adjusted with high accuracy.

  From a third aspect, the present invention provides a first object; a second object physically separated from the first object; a drive mechanism that drives the first object with respect to the second object; A measuring unit according to the present invention, wherein the detection object of each sensor is connected to one of the first object and the second object, and the sensor head of each sensor is connected to the other. is there.

  According to this, the positional relationship between the first object and the second object can be measured with high accuracy by the measuring device, and the first object is moved relative to the second object by the drive mechanism based on the measurement result. By driving, the positional relationship between the two can be adjusted with high accuracy.

  According to a fourth aspect of the present invention, there is provided a first optical unit comprising: an optical member; and a drive unit manufactured by the method for manufacturing a drive unit of the present invention that holds the optical member on the first object. It is.

  According to this, the measurement device constituting the drive unit can measure the positional relationship between the first object and the second object with high accuracy, and based on the measurement result, the drive unit can detect the first object and the second object. The positional relationship between the first object or the optical member and the second object can be adjusted with high accuracy by driving the optical member held by the first object with respect to the second object.

  From a fifth aspect, the present invention is a second optical unit comprising: an optical member; and the drive unit of the present invention that holds the optical member with the first object.

  Accordingly, the positional relationship between the first object and the second object can be measured with high accuracy by the measurement device that constitutes the drive unit, and the first object is moved by the drive mechanism based on the measurement result. By driving the two objects, the positional relationship between the first object or the optical member and the second object can be adjusted with high accuracy.

  According to a sixth aspect of the present invention, there is provided an optical apparatus comprising: a lens barrel; and one of the first and second optical units according to the present invention disposed at a predetermined position in the lens barrel.

  According to this, since either the first optical unit or the second optical unit of the present invention is provided, the optical performance of the optical device can be adjusted by adjusting the position and orientation of the optical member using the optical unit. Can be kept high for a long time.

  According to a seventh aspect of the present invention, there is provided an exposure apparatus that irradiates a mask with an energy beam and transfers the mask pattern onto the substrate, and is disposed on an optical path of the energy beam from the mask to the substrate. An exposure apparatus comprising the optical device according to the present invention.

  According to this, since the optical device of the present invention capable of maintaining high performance over a long period of time is arranged on the optical path of the energy beam from the mask to the substrate, a highly accurate mask pattern on the substrate It is possible to perform transfer to a long time using the optical device.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 schematically shows the overall configuration of an exposure apparatus 10 according to an embodiment. As will be described later, in the exposure apparatus 10, the projection optical apparatus PO is used. In the following, the optical axis direction of the projection optical apparatus PO is the Z-axis direction, and the plane orthogonal to this is shown in FIG. The description will be made assuming that the left-right direction in the drawing is the Y-axis direction and the direction orthogonal to the drawing is the X-axis direction.

  The exposure apparatus 10 projects an image of a part of a circuit pattern formed on a reticle R as a mask onto a wafer W as a substrate via a projection optical apparatus PO as an optical apparatus, and the reticle R and the wafer W. Are scanned relative to the projection optical apparatus PO in a one-dimensional direction (here, the Y-axis direction), so that the entire circuit pattern of the reticle R is stepped and scanned into each of a plurality of shot areas on the wafer W. It is transferred by the method.

  The exposure apparatus 10 emits EUV light (light in a soft X-ray region) EL as an energy beam, reflects the EUV light EL from the light source apparatus 12 and reflects a predetermined incident angle, for example, about 50 [mrad]. The illumination optical system including the folding mirror M that is bent so as to be incident on the pattern surface of the reticle R (the lower surface in FIG. 1 (the surface on the −Z side)) (the bending mirror M is disposed inside the lens barrel 52 of the projection optical apparatus PO). Although present, it is actually a part of the illumination optical system), the reticle stage RST that holds the reticle R, and the EUV light EL reflected by the pattern surface of the reticle R on the exposed surface of the wafer W (FIG. 1). Projection optical device PO that projects perpendicularly to the upper surface (the surface on the + Z side), a wafer stage WST that holds the wafer W, and the like. The exposure apparatus 10 is actually housed in a vacuum chamber (not shown).

  As the light source device 12, a laser excitation plasma light source is used as an example. This laser-excited plasma light source irradiates an EUV light generating substance (target) with high-intensity laser light, whereby the target is excited into a high-temperature plasma state and emitted when the target cools down, ultraviolet light, and ultraviolet light. , Visible light, and light in other wavelength ranges. In this embodiment, it is assumed that EUV light having a wavelength of 5 to 20 nm, for example, a wavelength of 11 nm is mainly used as the exposure beam.

  The illumination optical system includes an illumination mirror, a wavelength selection window and the like (all not shown), a bending mirror M, and the like. Moreover, the parabolic mirror as a condensing mirror in the light source device 12 also constitutes a part of the illumination optical system. The EUV light EL emitted from the light source device 12 and passing through the illumination optical system (the EUV light EL reflected by the bending mirror M) illuminates the pattern surface of the reticle R as arc-slit illumination light.

  The reticle stage RST is arranged on a reticle stage base 32 arranged along the XY plane, and the reticle stage base is generated by a magnetic levitation force generated by, for example, a magnetic levitation type two-dimensional linear actuator constituting the reticle stage drive system 34. 32 is levitated and supported. The reticle stage RST is driven with a predetermined stroke in the Y-axis direction by the driving force generated by the reticle stage drive system 34, and is also driven in a minute amount in the X-axis direction and the θz direction (rotation direction around the Z axis). It has become. In addition, this reticle stage RST has a Z-axis direction and an inclination direction with respect to the XY plane (the θx direction, which is the rotation direction around the X axis, and the Y axis) by adjusting the magnetic levitation force generated by the reticle stage drive system 34 at a plurality of locations. It can also be driven by a minute amount in the rotation direction (θy direction).

  An electrostatic chuck type (or mechanical chuck type) reticle holder (not shown) is provided on the lower surface side of the reticle stage RST, and the reticle R is held by the reticle holder. As the reticle R, a reflective reticle is used in correspondence with the illumination light EL being EUV light having a wavelength of 11 nm. The reticle R is held by a reticle holder with the pattern surface being the lower surface. The reticle R is made of a thin plate such as a silicon wafer, quartz, or low expansion glass, and a reflective film that reflects EUV light is formed on the surface (pattern surface) on the −Z side. This reflective film is a multilayer film in which about 50 pairs of molybdenum Mo and beryllium Be films are alternately laminated with a period of about 5.5 nm. This multilayer film has a reflectance of about 70% for EUV light having a wavelength of 11 nm. A multilayer film having the same configuration is also formed on the reflecting surfaces of the bending mirror M and other mirrors in the illumination optical system.

  On the multilayer film formed on the pattern surface of the reticle R, for example, nickel Ni or aluminum Al is applied on one surface as an absorption layer, and the absorption layer is patterned to form a circuit pattern.

  The EUV light that hits the part of the reticle R where the absorption layer remains is absorbed by the absorption layer, and the EUV light that hits the reflection film in the part where the absorption layer has been removed (the part from which the absorption layer has been removed). As a result, the EUV light including the circuit pattern information is directed to the projection optical apparatus PO described later as reflected light from the pattern surface of the reticle R.

  The position of reticle stage RST (reticle R) within the stage movement plane (position within the XY plane) is reticle laser interference that projects a laser beam onto a reflective surface provided (or formed) on the side surface of reticle stage RST. It is always detected by a meter (hereinafter referred to as “reticle interferometer”) 82R with a resolution of about 0.5 to 1 nm, for example. Here, actually, the reticle interferometer is a reticle X interferometer that measures the X-axis direction position (X position) of the reticle stage RST and a reticle Y interference that measures the Y-axis direction position (Y position) of the reticle stage RST. In FIG. 1, these are typically shown as a reticle interferometer 82R. At least one of the reticle Y interferometer and the reticle X interferometer, for example, the reticle Y interferometer, is a two-axis interferometer having two measurement axes, and the reticle stage RST ( In addition to the Y position of reticle R), the rotation amount (yawing amount) in the θz direction (rotation direction about the Z axis) can also be measured.

  The position of the reticle R in the Z-axis direction is composed of a light transmission system 13a that irradiates a detection beam obliquely with respect to the pattern surface, and a light reception system 13b that receives the detection beam reflected by the pattern surface of the reticle R. It is measured by a reticle focus sensor (13a, 13b). As this reticle focus sensor (13a, 13b), for example, a multipoint focal position detection system disclosed in Japanese Patent Laid-Open No. 6-283403 is used. For this reason, not only the Z position of the pattern surface of the reticle R but also the inclination (rotation amount in the θx and θy directions) with respect to the XY plane can be obtained based on the measurement value of the reticle focus sensor (13a, 13b).

  The measurement values of the reticle interferometer 82R and the reticle focus sensors (13a, 13b) are supplied to the main controller 20 (not shown in FIG. 1, refer to FIG. 10), and the main controller 20 passes the reticle stage drive unit 34 through. By driving the reticle stage RST, the position and orientation control of the reticle R in the 6-dimensional direction is performed. Note that wafer stage WST may be controlled via wafer stage drive unit 62 based on the measurement values of reticle interferometer 82R and reticle focus sensors (13a, 13b).

  The projection optical apparatus PO has a numerical aperture (NA) of 0.1, for example, and uses a reflection optical system composed of only a reflection optical element (mirror), as will be described later. That is 1/4 times larger is used. Therefore, the EUV light EL that is reflected by the reticle R and includes information on the pattern formed on the reticle R is projected onto the wafer W by the projection optical device PO, thereby reducing the pattern on the reticle R by 1/4 times. An image is transferred (formed) onto the wafer W. The specific configuration of the projection optical apparatus PO will be described in detail later.

  The wafer stage WST is disposed on a wafer stage base 60 disposed along the XY plane. For example, the wafer stage WST is mounted on the wafer stage base 60 by a wafer stage driving system 62 including a magnetic levitation type two-dimensional linear actuator. Has been supported by levitation. Wafer stage WST is driven by wafer stage drive system 62 in the X-axis direction and Y-axis direction with a predetermined stroke (the stroke is, for example, 300 to 400 mm) and in the θ direction (rotation direction about the Z-axis). Is driven by a minute amount. Wafer stage WST is configured to be able to be driven by a minute amount in the Z-axis direction and the tilt direction with respect to the XY plane by wafer stage drive system 62. The wafer stage drive system 62 includes a magnetically levitated two-dimensional linear actuator, etc., but is shown as a simple block in FIG. 1 for convenience of illustration.

  An electrostatic chuck type wafer holder (not shown) is placed on the upper surface of wafer stage WST, and wafer W is attracted and held by the wafer holder. The position of wafer stage WST is always detected by a wafer laser interferometer (hereinafter referred to as “wafer interferometer”) 82W arranged outside, for example, with a resolution of about 0.5 to 1 nm. In practice, an interferometer having a length measuring axis in the X-axis direction and an interferometer having a length measuring axis in the Y-axis direction are provided. In FIG. 1, these are typically shown as a wafer interferometer 82W. Has been. These interferometers are composed of multi-axis interferometers having a plurality of measurement axes, and in addition to the X and Y positions of wafer stage WST, rotation (yawing (θz rotation that is rotation around the Z axis)), pitching (X axis) Rotation around (θx rotation) and rolling (θy rotation around Y axis)) can also be measured.

  Further, the position of the wafer W in the Z-axis direction with respect to the lens barrel is measured by an oblique incidence type wafer focus sensor. As shown in FIG. 1, the wafer focus sensor is fixed to a column (not shown) that holds the lens barrel 52 of the projection optical apparatus PO, and irradiates a detection beam from an oblique direction to the upper surface of the wafer W. 14 a and a light receiving system 14 b that is fixed to a column (not shown) and receives a detection beam reflected by the wafer W surface. As this wafer focus sensor (14a, 14b), a multipoint focal position detection system similar to the reticle focus sensor (13a, 13b) is used.

  The measurement values of the wafer interferometer 82W and the wafer focus sensors (14a, 14b) are supplied to the main controller 20 (not shown in FIG. 1, refer to FIG. 10), and the main controller 20 controls the wafer stage drive system 62. Thus, the position and orientation control of wafer stage WST in the six-dimensional direction is performed.

  To measure the relative position of the alignment system ALG described later (so-called baseline measurement) at one end of the upper surface of wafer stage WST and the position where the pattern drawn on reticle R is projected onto the wafer W surface. An aerial image measuring instrument FM is provided. This aerial image measuring instrument FM corresponds to a reference mark plate of a conventional DUV exposure apparatus.

  Further, in the present embodiment, as shown in FIG. 1, the alignment system ALG is fixed to the lens barrel 52 of the projection optical apparatus PO. As this alignment system ALG, for example, an FIA (Field Image Alignment) system that irradiates broadband light onto an alignment mark (or aerial image measuring instrument FM) on the wafer W, receives the reflected light, and performs mark detection by image processing. The alignment sensor can be used.

  Next, the projection optical apparatus PO will be described in detail with reference to FIGS.

  FIG. 2 shows a schematic perspective view of the projection optical apparatus PO. The projection optical device PO includes five partial lens barrels 152a, 152b, 152c, 152d, and 152e sequentially connected from top to bottom along the Z-axis direction, and a flange FLG provided between the partial lens barrels 152b and 152c. And the mirrors M1, M2, M3, M4, M5, and M6 (see FIGS. 3A, 3B, and 4) disposed inside the lens barrel 52. Has been. On the side wall on the −Y side of the lens barrel 52, an opening 52a is formed to straddle both the partial lens barrel 152a and the partial lens barrel 152b. The partial lens barrels 152a to 152e and the flange FLG are formed of a material with less degassing such as stainless steel (SUS).

  As shown in FIG. 2, the partial barrel 152a is provided with a projecting portion 152f projecting to the outside on a part (−Z side and + Y side portion) of the outer peripheral surface in the vicinity of the lower end portion, and the upper surface as a whole. It is formed by a closed substantially cylindrical member. The partial barrel 152a has a rectangular opening 52b penetrating vertically on the upper wall (+ Z side wall).

  The partial barrel 152b is formed of a cylindrical member having a slightly larger diameter than the partial barrel 152a, and is connected to the lower side (−Z side) of the partial barrel 152a. The flange portion FLG having a larger diameter than the other portions is connected to the lower side of the partial barrel 152b.

  The partial barrel 152c is formed of a cylindrical member having a slightly smaller diameter than the partial barrel 152b, and is connected to the lower side (−Z side) of the flange FLG.

  The partial barrel 152d is made of a cylindrical member having a slightly smaller diameter than the partial barrel 152c, and is connected to the lower side (−Z side) of the partial barrel 152c.

  The partial barrel 152e is formed of a cylindrical member having a slightly smaller diameter than the partial barrel 152d whose bottom is closed, and is connected to the lower side (−Z side) of the partial barrel 152d. Although not shown, an opening for allowing the EUV light EL to pass from the projection optical device PO toward the wafer W is formed in the bottom wall (the wall on the −Z side) of the partial barrel 152e.

  FIG. 3A shows a perspective view of the six mirrors M1 to M6 arranged inside the lens barrel 52 as seen obliquely from above, and FIG. 3B shows these six mirrors M1. -M6 is shown in the perspective view seen from diagonally downward. As can be seen from these drawings, the six mirrors M1 to M6 are arranged in the order of the mirror M2, the mirror M4, the mirror M3, the mirror M1, the mirror M6, and the mirror M5 from the top. In FIGS. 3A and 3B, the reflecting surface of each mirror is hatched.

  In the present embodiment, the reflecting surfaces of the mirrors M1 to M6 each have a processing accuracy that is unevenness of about 1/50 to 1/60 of the exposure wavelength with respect to the design value, and the RMS value (standard deviation). Is set so that there is only a flatness error of 0.2 nm to 0.3 nm or less. The shape of the reflecting surface of each mirror is formed by alternately repeating measurement and processing.

  As can be seen from FIG. 3A and FIG. 4, the mirror M1 has a rotationally symmetric reflecting surface such as a spherical surface or an aspherical surface, and its rotationally symmetric axis is substantially the optical axis AX of the projection optical apparatus PO. It is a concave mirror whose position is adjusted to match. The mirror M1 is disposed inside the partial barrel 152c. The mirror M1 is held inside the partial barrel 152c by a drive unit 92 that also serves as a mirror holding mechanism, as shown in FIG.

The drive unit 92 includes a parallel link mechanism 41 ₁ as a drive mechanism, a part of which is attached to the inner surface of the partial barrel 152c, and an upper surface of the inner ring 42 as a first object constituting the parallel link mechanism 41 _1. , Respectively, and are provided with mirror holding members 44A, 44B, and 44C that hold three portions on the side surface of the mirror M1.

The parallel link mechanism 41 ₁ includes an outer ring 48 as a second object formed of an annular member constituting a base portion provided in a state inscribed in the inner peripheral surface of the partial barrel 152 c, and the outer ring 48. The inner ring 42, which is an end effector disposed above the outer ring 48, is connected to the inner ring 42 and the inner ring 42. 6 degrees of freedom relative to the outer ring 48 in the X, Y and Z axis directions and θx (rotation direction around the X axis), θy (rotation direction around the Y axis), and θz (rotation direction around the Z axis). And a drive mechanism 46 for driving in the direction.

  The drive mechanism 46 includes six links 110 having the same configuration, one end and the other end being connected to the outer ring 48 and the inner ring 42 through spherical pairs. As shown in FIG. 5, each link 110 includes a first shaft member 113 and a second shaft member 115 coupled (or connected) to the first shaft member 113. One end (lower end) is attached to the outer ring 48 via a hinge 111 having the same degree of freedom of movement as that of the ball joint, and the other end (upper end) of the second shaft member 115 is a hinge similar to the hinge 111 (not fixed). It is attached to the inner ring 42 via the figure). Here, the six links 110 form a pair by two, and the links 110 constituting each pair are respectively connected via hinges (not shown) in a state where the upper ends of the respective second shaft members 115 are close to each other. It is attached to the inner ring 42.

  At least one of the second shaft member 115 and the first shaft member 113 constituting each link 110 has a length of the link 110, that is, a lower end of the first shaft member 113 and an upper end of the second shaft member 115. An actuator capable of changing the distance is provided. As such an actuator, it is conceivable to use a linear cylinder, a small motor, a piezoelectric element, or the like, but in this embodiment, a piezoelectric element is used as an example.

As can be seen from the above description, the parallel link mechanism 41 ₁ includes a stretchable link six, a parallel link mechanism called Stewart platform type.

  The mirror holding members 44A to 44C are arranged in a predetermined positional relationship on the upper surface (+ Z side surface) of the inner ring 42, and are divided into three portions on the outer peripheral surface of the mirror M1, for example, three equal parts on the outer periphery with a central angle of 120 ° intervals. Each point is held. Each of these mirror holding members 44 </ b> A to 44 </ b> C has a substantially inverted U shape, and is set so that the rigidity of the inner ring 42 in the radial direction is low.

  Each of the mirror holding members 44A to 44C and the mirror M1 are fixed by a mechanical clamp mechanism or an adhesive or the like, so that the mirror M1 maintains a predetermined positional relationship with the inner ring 42. Is held by.

  As described above, since the mirror M1 is held by the mirror holding members 44A to 44C having low rigidity in the radial direction of the inner ring 42, the mirror M1 is thermally expanded. Even in this case, deformation due to thermal expansion of the mirror M1 can be absorbed, and distortion of the mirror M1 can be suppressed.

  Furthermore, as shown in FIG. 5, measuring devices 71 </ b> A and 71 </ b> B that measure relative position information in a plurality of different directions between the inner ring 42 and the outer ring 48 while being sandwiched between each pair of two links 110. And 71C are provided.

  FIG. 6A shows a perspective view of one measuring device 71A among the three measuring devices 71A to 71C. The measuring device 71A shown in FIG. 6A is composed of two parts, a scale part 53A and a sensor head part 53B shown in FIG. 6B.

  As shown in FIG. 5, in a state where the measuring device 71A is incorporated in the drive unit 92, one end (upper end) of the scale portion 53A is fixed to the inner ring 42, and one end (lower end) of the sensor head portion 53B is fixed. The outer ring 48 is fixed.

  In FIG. 6A, for convenience of explanation, the direction of the axis corresponding to the tangential direction of the inner ring 42 (or outer ring 48) at the mounting position of the measuring device 71A is the X ′ axis direction, and the X ′ axis The direction of the axis perpendicular to the direction and the Z-axis direction (vertical direction) is shown as the Y′-axis direction. The same applies to FIG. 6B, FIG. 7, FIG. 8A, FIG. 8B, and FIG.

  As shown in FIG. 6B, the scale portion 53A has positional information in the X′-axis direction of the inner ring 42 with respect to the outer ring 48 (that is, relative to the X-axis direction between the inner ring 42 and the outer ring 48). A first scale portion 56a for measuring position information) is provided as a detection target provided along the X′-axis direction at one end (−Y ′ side) of the Y′-axis direction. 55A and the second scale 56b for measuring the Z-axis position information of the inner ring 42 relative to the outer ring 48 (that is, the relative position information of the inner ring 42 and the outer ring 48 in the Z-axis direction) is Y ′. A second scale portion 55B as a detection target provided at one end (−Y ′ side) in the axial direction in parallel to the X′Z plane, and first and second scale portions 55A and 55B. A first holding member 57 for holding in a predetermined positional relationship, and a.

  The first holding member 57 as a whole has a complicated shape as shown in FIG. 7 which is an exploded perspective view of the measuring device 71A. That is, the first holding member 57 is provided so as to protrude toward the + Y ′ side at the first portion 157a parallel to the X′Z plane and having the Z-axis direction as the longitudinal direction and the upper end portion of the first portion 157a. A second portion 157b, a third portion 157c projecting toward the + Y ′ side at the lower end of the first portion 157a (this third portion 157c faces the second portion 157b), and A fourth portion 157d extending downward from the + Y ′ side end of the third portion 157c, a fifth portion 157e extending in the + X ′ direction from a portion other than the upper end of the fourth portion 157d, A sixth portion 157f parallel to the Y′Z surface projecting from the + X side end portion of the fifth portion 157e to the −Y ′ side, and X ′ connecting the sixth portion 157f and the fifth portion 157e. And a plate-like seventh portion 157g parallel to the Y ′ plane.

Two round holes 57e are formed in the second portion 157b, and the second portion 157b is screwed to the inner ring 42 through the round holes 57e, whereby the scale portion 53A (first 1 holding member 57) is attached to the parallel link mechanism 41 ₁ .

  In the state of FIG. 6, the first scale portion 55A is fixed to the upper surface 57a of the seventh portion 157g of the first holding member 57, and the second scale portion 55B is fixed to the lower surface 57b of the seventh portion 157g. Also, screw holes 57c and 57d are formed in the vicinity of the lower end portion of the surface on the −Y ′ side of the first portion 157a and separated by a predetermined distance in the X ′ axis direction.

  As can be seen from FIG. 7, the first scale portion 55 </ b> A has a reverse U-shaped Y′Z cross section, and the first scale portion 55 </ b> A extends in the X′-axis direction at the −Y ′ side end. Although not shown, the scale 56a is formed with a large number of slits at a predetermined pitch along the X′-axis direction. The lower surface of the + Y side end portion of the first scale portion 55A is fixed to the surface 57a of the first holding member 57, and in this fixed state, the first scale 56a is substantially parallel to the X′Z surface. (See FIG. 6B).

  As can be seen from FIG. 7, the second scale portion 55B has a substantially L shape when viewed from the + X ′ direction and a substantially L shape when viewed from the + Z direction. In the second scale 56b located at the end, a large number of slits are formed at a predetermined pitch along the Z-axis direction. The second scale portion 55B has its upper end surface (+ Z end surface) fixed to the surface 57b of the first holding member 57, and in this fixed state, the second scale 56b is substantially parallel to the X′Z surface. (See FIG. 6B).

  As shown in FIG. 6B, the sensor head portion 53B holds the first sensor head 59A, the second sensor head 59B, and the first and second sensor heads 59A and 59B in a predetermined positional relationship. A second holding member 61.

  The second holding member 61 has a special shape as shown in FIG. 7 as a whole. In other words, the second holding member 61 extends in the −X ′ direction to the first portion 61a having a substantially rectangular parallelepiped shape whose longitudinal direction is the Z-axis direction and the lower end portion of the end surface on the −X ′ side of the first portion 61a. There are three parts: a second part 61b provided and a flat plate-like third part 61c projecting toward the + X ′ side at the center in the height direction of the surface on the + X ′ side of the first part 61a. ing. Two screw holes 61d in the Z-axis direction are formed on the upper surface of the third portion 61c, and a screw hole 61f is formed substantially at the center of the + X ′ side surface of the third portion 61c. Two screw holes 61g are formed in a part below the center in the vertical direction (Z-axis direction) of the surface on the + X ′ side of the first portion 61a, and −X ′ of the first portion 61a. A screw hole 61e indicated by a dotted line in FIG. 7 is formed on the side surface.

  The first sensor head 59A has a housing having a substantially U-shaped cross section with a groove 59c formed on the upper surface thereof, and a light emitting element such as a light emitting diode (LED) provided inside the groove 59c (for example, + Y ′ side). And a slit plate provided at a position facing the light emitting element (for example, on the −Y ′ side in the groove 59c) (this slit plate has a small number of slits having the same pitch as the first scale 56a). ) And a light receiving element such as a photodiode (PD).

  The bolt 81 is screwed into the above-described two Z-axis direction screw holes 61d through the two through holes 59e in the vertical direction formed in the -Y 'side portion of the first sensor head 59A. One sensor head 59A is screwed to the upper surface of the third portion 61c. Here, the diameter of the through hole 59e is larger than the diameter of the bolt and smaller than the outer diameter of the head of the bolt.

  As shown in FIG. 6A, when the scale portion 53A and the sensor head portion 53B are combined, the first scale 56a described above is inserted into the groove 59c of the first sensor head 59A. It is like that. In this state, when light is emitted from the light emitting element, the light reaches the slit plate through the slit of the first scale 56a, or passes through the slit of the slit plate so as to reach the light receiving element. It has become. In this case, every time the first scale 56a moves by one pitch of the slit, the amount of light incident on the light receiving element changes from one place to another in a period from a bright place to a dark place. Accordingly, the amount of movement of the first scale 56a in the measurement direction (X′-axis direction) can be determined by measuring the number of output cycles of the light receiving element. That is, in this embodiment, the first scale 56a serves as a main scale, and the slit plate serves as an index scale. The first scale 56a is provided by these scales, the light emitting element, and the light receiving element. A first linear encoder that measures a change in relative position of the first scale portion 55A (scale portion 53A) in the X′-axis direction with respect to the first sensor head 59A is configured. The measurement resolution of the first linear encoder is determined by the slit pitch, and in the present embodiment, the resolution is about 0.5 to 1 nm as an example.

  The direction of the second sensor head 59B held by the second holding member 61 is different from that of the first sensor head 59A, but is configured similarly. That is, the second sensor head 59B is a light-emitting diode that is disposed so as to face each other through a U-shaped housing having a groove 59d formed on the + X ′ side surface and the groove 59d of the housing. A light-emitting element such as an LED, and a light-receiving element such as a slit plate (slits are arranged in the Z-axis direction) and a photodiode (PD).

  The bolt 83 is screwed into the two screw holes 61g through the two through holes 59f in the X′-axis direction formed in the −Y ′ side portion of the second sensor head 59B, whereby the second sensor The head 59B is screwed to the + X ′ side surface of the first portion 61a of the second holding member 61. Here, the diameter of the through hole 59f is larger than the diameter of the bolt and smaller than the outer diameter of the head of the bolt.

  As shown in FIG. 6A, when the scale portion 53A and the sensor head portion 53B are combined, the second scale 56b described above is inserted into the groove 59d of the second sensor head 59B. In this state, in the same manner as described above, the light emitting element emits light, the second scale 56b is moved in the Z-axis direction, and the number of output cycles of the light receiving element is measured. The amount of movement in the measurement direction (Z-axis direction) can be understood. That is, in the present embodiment, the second scale 56b serves as a main scale, and the slit plate serves as an index scale. The second scale 56b is provided by these scales, the light emitting element, and the light receiving element. A second linear encoder that measures a change in the relative position of the second scale portion 55B (scale portion 53A) in the Z-axis direction with respect to the second sensor head 59B is configured. The measurement resolution of the second linear encoder is determined by the slit pitch, and in the present embodiment, the resolution is about 0.5 to 1 nm as an example.

  The measuring device 71A is configured as described above. However, in the state where the measuring device 71A is incorporated in the drive unit 92 as shown in FIG. 5, the second portion 157b of the first holding member 57 described above. Is fixed to the inner ring 42 by screws or the like, and the second portion 61b of the second holding member 61 is fixed to the outer ring 48 by screws or the like. Accordingly, relative position information regarding the X′-axis direction (tangential direction) between the inner ring 42 (and mirror M1) and the outer ring 48, that is, the X′-axis direction (tangential direction) of the inner ring 42 (and mirror M1) with respect to the outer ring 48. ) Can be measured by the above-described first linear encoder, and the position change in the Z-axis direction of the inner ring 42 (and the mirror M1) with respect to the outer ring 48 can be measured by the above-described second linear encoder. It can be done. The measured values of the first linear encoder and the second linear encoder are sent to the main controller 20 shown in FIG.

  The other measuring devices 71B and 71C are configured in the same manner as the measuring device 71A, and the second portion 157b of the first holding member 57 and the second portion 61b of the second holding member 61 that constitute each of the measuring devices 71B and 71C are provided. The inner ring 42 and the outer ring 48 are respectively fixed. The measurement values of the first linear encoder and the second linear encoder that constitute each of these measuring devices 71B and 71C are sent to the main controller 20 in FIG.

Accordingly, the position information (movement amount information) of the inner ring 42 (and the mirror M1) with respect to the outer ring 48 is measured by each of the measurement devices 71A to 71C with respect to each of two different tangential directions and Z-axis directions. Therefore, based on the measurement results of the measuring devices 71A to 71C (that is, the output values of the first and second linear encoders constituting the measuring devices 71A to 71C, respectively), the X, Y, Z, θx, The position and orientation in the θy and θz directions can be calculated. Therefore, in the main controller 20, based on the output values of the first and second linear encoders constituting the measuring devices 71A to 71C, the parallel link mechanism 41 ₁ (more precisely, the length of each of the six links 110). ) Can be adjusted to adjust the position and orientation of the inner ring 42 and thus the mirror M1 held in the X, Y, Z, θx, θy, and θz directions.

  Here, the manufacturing method of the drive unit 92 described above will be described based on the flowchart of FIG. 9 and FIGS.

  First, in step 202 of FIG. 9, the inner ring 42 and the outer ring 48 are assembled via the six links 110. Note that the inner ring 42 and the outer ring 48 are manufactured by being processed into predetermined dimensions in advance using a known metal processing machine or the like.

  Next, in step 204 of FIG. 9, for each of the measuring devices 71A, 71B, and 71C, the first scale portion 55A is fixed to the surface 57a of the first holding member 57, and the second scale portion 55B is fixed to the surface 57b. In this case, for example, in the manufacturing stage of the first holding member 57, positioning concave portions (guides) or the like are provided in the portions for fixing the first and second scale portions 55A and 55B, respectively. The first and second scale portions 55A and 55B are mechanically positioned with respect to the first holding member 57 in a desired state. By this positioning, the first scale 56a can be set in the tangential direction of the inner ring 42 (for example, the X′-axis direction in the case of the first scale 56a of the measuring device 71A), and the second scale 56b can be set to Z. It can be set in the axial direction. In this way, the scale portion 53A shown in FIG. 6B is assembled.

  In the next step 206, the first sensor head portion 59A and the second sensor head portion 59B are temporarily fixed to the second holding member 61 for each of the measuring devices 71A, 71B, and 71C. In this case, the first sensor head portion 59A and the second sensor head portion 59B are temporarily fixed to the second holding member 61 by the screwing described above. In this way, provisional assembly of the sensor head portion 53B shown in FIG. 6B is performed.

  In the next step 208, for each of the measuring devices 71A, 71B and 71C, the scale part 53A and the sensor head part 53B assembled above are assembled as shown in FIG. In each of the measuring devices 71A, 71B and 71C, the wirings of the first and second linear encoders and the power source are connected to start measurement by the first and second linear encoders, and based on the outputs of the respective linear encoders. The position (including rotation) of the first and second sensor head portions 59A and 59B is finely adjusted.

  This fine adjustment will be described by taking the measuring device 71A as an example. First, while loosening the aforementioned bolt 81 and monitoring the output of the first linear encoder, the first sensor head portion 59A is slightly moved in the X′-axis direction on the third portion 61c of the second holding member 61 and Z Make a slight rotation around the axis. Then, based on the output of the first linear encoder, the origin of the main scale coincides with the origin of the index scale, and the measurement axis of the first linear encoder coincides with the X′-axis direction, that is, the groove 59c of the first sensor head portion 59A. The bolt 81 is tightened by setting the position of the first sensor head 59A in the X′-axis direction and the rotation around the Z-axis so that the longitudinal direction of the first sensor head 59A coincides with the longitudinal direction (X′-axis direction) of the first scale 56a. Next, the bolt 83 is loosened and the second sensor head portion 59B is slightly moved in the Z-axis direction and slightly rotated around the X ′ axis while monitoring the output of the second linear encoder. Then, based on the output of the second linear encoder, the origin of the main scale coincides with the origin of the index scale, and the measurement axis of the second linear encoder coincides with the Z-axis direction. The direction position and the rotation about X ′ are set and the bolt 83 is tightened to fix the second sensor head portion 59B to the first portion 61a of the second holding member 61. After finely adjusting the positions (including rotation) of the first and second sensor head portions 59A and 59B in this way, the connection between the first and second linear encoders and the power supply is released.

  Next, in step 212, the fixture 65 shown in FIG. 8A is used for each of the measuring devices 71A, 71B, and 71C so as to maintain the positional relationship between the scale unit 53A and the sensor head unit 53B at that time. The scale part 53A and the sensor head part 53B are fixed via

  Here, as shown in FIG. 8A, the fixture 65 includes a plate-like portion 65f having a substantially plate-like shape, and both ends in the X′-axis direction on the −Y ′ side of the lower surface of the plate-like portion 65f. The first leg portion 65g and the second leg portion 65h are provided to protrude from the portion toward the −Z direction.

  A notch 65e is formed at the + Y ′ side end of the plate-like portion 65f, and round holes 65a, 65b are formed in the Y′-axis direction so as to penetrate through the −Y′-side end surface of the plate-like portion 65f. Has been. In addition, a round hole 65c is formed in a state of penetrating in the X′-axis direction somewhat below the center of the first leg 65g in the Z-axis direction, and is somewhat lower than the center of the second leg 65g in the Z-axis direction. On the side, a round hole 65d is formed in a state of penetrating in the X′-axis direction so as to face the round hole 65c.

  Accordingly, in a state where the positional relationship between the scale portion 53A and the sensor head portion 53B is adjusted, the fixture 65 is engaged with each measuring device (the fixture 65 is connected to the first via the notch portion 65e of the fixture 65). The first holding member 57 with a bolt (not shown) via the round holes 65a and 65b and screw holes 57c and 57d formed in the first holding member 57 of the scale portion 53A. The scale portion 53A and the sensor are secured by screwing and screwing bolts (not shown) into the screw holes 61e and 61f formed in the second holding member 61 of the sensor head portion 73B through the round holes 65c and 65d. Both can be fixed while maintaining the positional relationship with the head portion 53B. FIG. 8B shows a state in which the fixture 65, the scale portion 53A, and the sensor head portion 53B are integrated in this way.

  Next, in step 214 of FIG. 9, each of the measuring devices 71A, 71B, and 71C is incorporated into the drive unit 92. That is, for each of the measuring devices 71A, 71B, and 71C, the second portion 157b of the first holding member 57 constituting the scale portion 53A is fixed to the upper surface of the inner ring 42 by screwing or the like to constitute the sensor head portion 53B. The second portion 61b of the second holding member 61 is fixed to the upper surface of the outer ring 48 by screwing or the like.

  Next, in step 216, the fixture 65 is removed from each of the measuring devices 71A to 71C incorporated in the drive unit 92 in step 214. That is, the fixing between the scale unit 53A and the sensor head unit 53B of each of the measuring devices 71A to 71C is released.

  As described above, the manufacture of the drive unit 92 in which the measuring devices 71A to 71C in which the positional relationships including the origin positions of two different measurement axes (measurement axes of the first and second linear motors) are adjusted is incorporated. finish.

Returning to FIG. 3A, the position of the mirror M2 is adjusted so that its lower surface is a rotationally symmetric reflecting surface such as a spherical surface or an aspherical surface, and its rotationally symmetric axis coincides with the optical axis AX of the projection optical apparatus PO. (See FIGS. 3B and 4). The mirror M2 is held in the partial barrel 152a of FIG. 2 by a drive unit that also serves as a mirror holding mechanism that is configured in the same manner as the drive unit 92 described above, and the parallel link mechanism 41 ₁ that forms the drive unit. The parallel link mechanism 41 ₂ (see FIG. 10) having the same configuration as that shown in FIG. Further, the mirror M2 is constituted in the same manner as the above-described measuring device 71 a to 71 c, the same way the measuring device attached to the parallel link mechanism 41 ₂ 72A to 72C (see FIG. 10), the directions of six degrees of freedom Each position is measured.

As shown in FIGS. 3A, 3B, and 4, the mirror M3 is a convex mirror whose upper surface is a reflecting surface, and is located away from the optical axis AX of the projection optical apparatus PO. Is arranged. However, as shown in FIG. 4, the reflecting surface of the mirror M3 is a part of a rotationally symmetric surface such as a spherical surface or an aspherical surface indicated by a broken line 94a, and the rotationally symmetric axis substantially coincides with the optical axis AX. The position of the mirror M3 is adjusted to the position. This mirror M3 is held in the partial barrel 152b of FIG. 2 by a drive unit that also serves as a mirror holding mechanism configured similarly to the drive unit 92 described above, and the parallel link mechanism 41 ₁ that constitutes the drive unit. It can be driven in the direction of 6 degrees of freedom by a parallel link mechanism 41 ₃ (see FIG. 10) having the same configuration as in FIG. Further, the mirror M3 is configured in the same manner as the above-described measuring devices 71A to 71C, and similarly, the measuring devices 73A to 73C (see FIG. 10) attached to the parallel link mechanism 41 ₃ are arranged in the direction of 6 degrees of freedom. Each position is measured.

3A, 3B, and 4, the mirror M4 is a concave mirror whose lower surface is a reflecting surface, and is greatly deviated from the optical axis AX of the projection optical apparatus PO. Placed in position. However, as shown in FIG. 4, the reflecting surface of the mirror M4 is a part of a rotationally symmetric surface such as a spherical surface or an aspherical surface indicated by a broken line 94b, and the rotational symmetry axis substantially coincides with the optical axis AX. The position of the mirror M4 is adjusted to the position. The mirror M4 is held in the partial barrel 152a of FIG. 2 in a state where, for example, one link protrudes from the overhanging portion 152f by a drive unit that also serves as a mirror holding mechanism configured in the same manner as the drive unit 92 described above. The parallel link mechanism 41 ₄ (see FIG. 10) having the same configuration as the above-described parallel link mechanism 41 ₁ constituting the drive unit can be driven in the direction of six degrees of freedom. Further, the mirror M4 is constituted in the same manner as the previously described measuring device 71 a to 71 c, the same way the measuring device attached to the parallel link mechanism 41 ₄ 74A to 74C (see FIG. 10), the directions of six degrees of freedom Each position is measured.

As shown in FIG. 3 (A), FIG. 3 (B), and FIG. 4, the mirror M5 has a generally horseshoe shape as a whole in which the upper surface is a reflective surface and a notch is formed in a part thereof. It is a convex mirror. The mirror M5 has a reflecting surface that is a part of a rotationally symmetric surface such as a spherical surface or an aspherical surface, and the position of the mirror M5 is adjusted so that the rotationally symmetric axis substantially coincides with the optical axis AX of the projection optical apparatus PO. Yes. In the mirror M5, the above-described notch serving as the optical path of the illumination light EL is formed in a portion on the −Y side from the optical axis AX. The mirror M5 is held in the partial barrel 152e of FIG. 2 by a drive unit that also serves as a mirror holding mechanism that is configured in the same manner as the drive unit 92 described above, and the parallel link mechanism 41 ₁ that forms the drive unit. It can be driven in the direction of 6 degrees of freedom by a parallel link mechanism 41 ₅ (see FIG. 10) having the same configuration as in FIG. Further, the mirror M5 is constituted in the same manner as the above-described measuring device 71 a to 71 c, the same way the measuring device attached to the parallel link mechanism 41 ₅ 75a to 75c (see FIG. 10), the directions of six degrees of freedom Each position is measured.

As shown in FIGS. 3A, 3B, and 4, the mirror M6 has a substantially horseshoe shape as a whole in which the lower surface is a reflecting surface and a notch is formed in a part thereof. It is a concave mirror. The mirror M6 has a reflection surface that is part of a rotationally symmetric surface such as a spherical surface or an aspherical surface, and the position of the mirror M6 is adjusted so that the rotationally symmetric axis substantially coincides with the optical axis AX of the projection optical apparatus PO. Yes. In the mirror M6, the above-described notch serving as the optical path of the illumination light EL is formed on the + Y side of the optical axis AX. The mirror M6 is held in the partial barrel 152e of FIG. 2 by a drive unit that also serves as a mirror holding mechanism configured in the same manner as the drive unit 92 described above, and the parallel link mechanism 41 ₁ that constitutes the drive unit. It can be driven in the direction of 6 degrees of freedom by a parallel link mechanism 41 ₆ (see FIG. 10) having the same configuration as in FIG. Further, the mirror M6 is configured similarly to the above-described measuring device 71 a to 71 c, the same way the measuring device attached to the parallel linkage 41 ₆₂ 76a to 76c (see FIG. 10), the directions of six degrees of freedom Each position is measured.

In the present embodiment, as shown in FIG. 10, the position information of the mirror M2 measured by the measuring devices 72A to 72C and the mirror M3 measured by the measuring devices 73A to 73C, similarly to the position information of the mirror M1. Position information of the mirror M4 measured by the measuring devices 74A to 74C, position information of the mirror M5 measured by the measuring devices 75A to 75C, and position of the mirror M6 measured by the measuring devices 76A to 76C. Information is supplied to the main controller 20. Main controller 20 adjusts the positions of mirrors M2 to M6 in the 6-degree-of-freedom direction via parallel link mechanisms 41 _{2 to} 41 ₆ based on the position information of mirrors M2 to M6, as with mirror M1.

  Here, the operation of the projection optical apparatus PO configured as described above will be described with reference to FIGS. The EUV light EL emitted from the light source device 12 and incident on the inside of the lens barrel 52 through the opening 52 a formed in the lens barrel 52 of the projection optical device PO is emitted from the illumination optical system disposed in the lens barrel 52. The light is reflected substantially upward by the bending mirror M constituting a part, and enters the reticle R through the opening 52b of the lens barrel 52 at a predetermined incident angle. Then, the EUV light EL reflected by the pattern surface of the reticle R is reflected by the mirror M1 and collected on the reflection surface of the mirror M2. Next, the EUV light EL reflected by the reflecting surface of the mirror M2 is sequentially reflected by the mirrors M3 and M4, passes through the notch of the mirror M6, enters the mirror M5, and is reflected by the reflecting surface of the mirror M5. Thereafter, the EUV light EL reflected by the mirror M5 is reflected by the mirror M6, and is irradiated onto the wafer W through the notch of the mirror M5 as a pattern imaging light beam.

  FIG. 10 schematically shows the main configuration of the control system of the exposure apparatus 10 of the present embodiment. This control system is mainly configured of a main controller 20 that controls the entire apparatus in an integrated manner.

  Next, regarding the manufacturing method of the projection optical apparatus PO of the present embodiment, the manufacturing procedure of the projection optical apparatus PO will be briefly described with reference to FIG.

[Step 1]
In Step 1 of FIG. 11, first, as described above, the drive units corresponding to each of the mirrors M1 to M6 are manufactured, and the optical members constituting the projection optical apparatus PO are configured according to the design values based on predetermined design mirror data. The mirror barrels 152a to 152e into which the mirrors M1 to M6 and each mirror and the drive unit are incorporated are manufactured.

  That is, each mirror is processed from a predetermined optical material according to a predetermined design value using a known mirror processing machine, and the divided lens barrels 152a to 152e are processed using a predetermined material using a known metal processing machine or the like. (Stainless steel, brass, ceramic, etc.) are processed into shapes having predetermined dimensions. For each mirror, it is necessary to measure the aspherical axis and the like.

[Step 2]
In step 2, six units (hereinafter referred to as “mirror units”) each composed of each mirror and a drive unit having a mirror holding member that holds each mirror are assembled according to preset design values. Although not shown, three adjustment devices described in the pamphlet of International Publication No. 02/16993 are provided in the portions (three places) corresponding to the measurement devices on the lower surface side of the outer ring 48 of each mirror unit. Is provided.

[Step 3]
In step 3, each mirror unit assembled in step 2 is incorporated in the corresponding split lens barrel.

[Step 4]
Next, in step 4, the eccentricity of each of the divided lens barrels is adjusted using a device that can guarantee straightness such as a rotary table using an air spindle, and each of the divided lens barrels is separated into an adjacent divided lens barrel (ring). The lens barrel 52 is once assembled by temporarily fixing it via a washer. Then, the distance between adjacent divided lens barrels (specifically, the thickness of the separation ring (ring washer)) is obtained, and the assembled barrels are disassembled to obtain the thickness of each separation ring (ring washer). The thickness is changed to a predetermined thickness. Note that a plurality of types of ring washers may be prepared, and adjustment may be performed by selecting an optimal ring washer. Then, each of the divided lens barrels and a plurality of separation rings (ring washers) whose thicknesses are adjusted are divided in the order of a divided lens barrel, a separated ring, a divided lens barrel, a separated ring, a divided lens barrel, and so on. Then, assembling is performed sequentially, and the eccentric amount of each assembled barrel is adjusted with a known eccentricity adjusting machine. After the adjustment, each of the divided lens barrels is bolted to the adjacent divided lens barrels via a separation ring, whereby the assembly (and coarse adjustment) of the projection optical device is temporarily completed.

[Step 5]
In step 5, the optical characteristics of the projection optical apparatus PO assembled in step 4, such as wavefront aberration, are measured using a wavefront aberration measuring device, and based on the measurement result of the wavefront aberration, the projection optical apparatus PO of each mirror is measured. The amount of positional deviation in the X-axis direction and the Y-axis direction with respect to the optical axis, that is, the amount of eccentricity of each divided lens barrel in which each mirror is incorporated is obtained, and based on this, each of each mirror is obtained by the three adjusting devices described above. Adjust the positional relationship with respect to the split lens barrel. Here, with the three adjusting devices described above, the relative positional relationship of the mirror unit with respect to the divided lens barrel can be adjusted with six degrees of freedom.

  Thereafter, Step 5 is repeated until the wavefront aberration reaches a desired value, and the projection optical apparatus PO is completed when the wavefront aberration reaches the desired value.

  Although the description will be mixed, as described above, each mirror can be driven in the direction of 6 degrees of freedom by the parallel link mechanism. However, the drive range of each mirror by the parallel link mechanism is very narrow. In order to maximize the drive range of each mirror, it is necessary to set each parallel link to the neutral position (origin position) of the movable range during assembly manufacture. Therefore, in the present embodiment, each of the parallel link mechanisms being assembled and manufactured is assembled in the state where the movable range is set to the neutral position (origin position). In the manufacturing and assembly stage, the mirror is not driven by the parallel link mechanism, so that the fixtures of the measuring devices 71A to 76C are not removed until the projection optical device is assembled. It's also good.

  Next, the operation of the exposure process by the exposure apparatus 10 of the present embodiment configured as described above will be described.

  First, reticle R is transported by a reticle transport system (not shown) and held on reticle stage RST in the loading position. Next, main controller 20 (see FIG. 10) controls the positions of wafer stage WST and reticle stage RST, and a projection image of a reticle alignment mark (not shown) formed on reticle R onto the surface of wafer W is a space. The projection position of the reticle pattern image on the surface of the wafer W is obtained based on the detection result and the measurement values of the interferometers 82R and 82W. That is, reticle alignment is performed.

  Next, main controller 20 moves wafer stage WST so that aerial image measuring instrument FM is positioned directly below alignment system ALG, and the detection signal of alignment system ALG and the measured value of wafer interferometer 82W at that time are detected. Based on the above, the relative position between the projection position of the pattern image of the reticle R on the wafer W surface and the alignment system ALG, that is, the baseline of the alignment system ALG is obtained.

  When the baseline measurement is completed, the main controller 20 performs so-called EGA wafer alignment, and obtains the position coordinates of all shot areas on the wafer W.

  Then, step-and-scan exposure is performed using the EUV light EL as exposure illumination light as follows. That is, main controller 20 monitors the position information from wafer interferometer 82W according to the position information of each shot area on wafer W obtained as a result of the wafer alignment, and causes wafer stage WST to expose the first shot area. And the reticle stage RST is moved to the scan start position (acceleration start position), and scanning exposure of the first shot is performed. At the time of this scanning exposure, main controller 20 drives reticle stage RST and wafer stage WST in opposite directions, and the speeds of both stages so that the speed ratio between the two accurately matches the projection magnification of projection optical apparatus PO. Is controlled to perform exposure (reticle pattern transfer). Thereby, a transfer image of a circuit pattern of, for example, 25 mm (width) × 50 mm (length in the scanning direction) is formed in the first shot region on the wafer W.

  When scanning exposure of the first shot area is completed as described above, main controller 20 performs stepping operation between shots to move wafer stage WST to a scanning start position (acceleration start position) for exposure of the second shot area. I do. Then, scanning exposure of the second shot area is performed in the same manner as described above. Thereafter, the same operation is performed after the third shot area.

  In this way, the stepping operation between shots and the scanning exposure operation for the shots are repeated, and the pattern of the reticle R is transferred to all shot regions on the wafer W by the step-and-scan method.

  Here, during the above-described scanning exposure and alignment, the distance between the surface of the wafer W and the projection optical device PO and the inclination with respect to the XY plane are measured by the wafer focus sensor (14a, 14b), and the main controller 20 measures the wafer W. Wafer stage WST is controlled so that the distance and parallelism between the surface and projection optical apparatus PO are always constant. Further, in main controller 20, the distance between projection optical apparatus PO during exposure (during reticle pattern transfer) and pattern surface of reticle R is always constant based on the measurement values of reticle focus sensors (13a, 13b). The reticle stage RST and wafer stage WST are synchronously moved along the Y-axis direction while adjusting the position of the reticle R in the optical axis direction (Z direction) of the projection optical apparatus PO so as to be maintained.

  Further, in the exposure apparatus 10 of the present embodiment, for example, based on an operator's instruction, the main controller 20 adjusts predetermined imaging characteristics of the projection optical apparatus PO. As a premise for adjusting the imaging characteristics of the projection optical apparatus, it is necessary to accurately measure the imaging characteristics. As the measurement method, for example, measurement is performed by measuring a resist image obtained by performing exposure using a measurement mask on which a predetermined measurement pattern is formed and developing a wafer on which a projection image of the measurement pattern is transferred and formed. A method (printing method) for calculating imaging characteristics based on the result is mainly employed.

When the calculation result of the imaging characteristic is input by the operator, the main controller 20 performs a predetermined calculation to adjust the imaging characteristic of the projection optical apparatus PO to a desired state. The driving amounts (including zero) in the X-axis and Y-axis directions of M1 to M6 are calculated, and the positions of the mirrors M1 to M6 are adjusted via the parallel link mechanisms 41 _{1 to} 41 ₆ according to the calculation results. At the time of this adjustment, the main controller 20 uses the position information of the mirror M1 measured by the measuring devices 71A to 71C, the position information of the mirror M2 measured by the measuring devices 72A to 72C, and the mirror measured by the measuring devices 73A to 73C. The position information of M3, the position information of the mirror M4 measured by the measuring devices 74A to 74C, the position information of the mirror M5 measured by the measuring devices 75A to 75C, and the position information of the mirror M6 measured by the measuring devices 76A to 76C. Based on this, the parallel link mechanisms 41 _{1 to} 41 ₆ are feedback-controlled so that the positions of the mirrors M1 to M6 coincide with the target positions. Thereby, the imaging characteristics of the projection optical apparatus PO are adjusted to a desired state.

Even during actual exposure, the measured values of the measuring devices 71A to 76C are constantly monitored, and the measured values become desired values (for example, initial values adjusted as described above). As described above, the parallel link mechanisms 41 _{1 to} 41 ₆ may be feedback-controlled.

  As can be seen from the above description, in the present embodiment, the mirror M1 (M2 to M6) and the drive unit 92 constitute the optical unit of the present invention.

As described above in detail, according to the measurement device of the present embodiment, the measurement devices 71A to 71C are connected to the scale portion 53A connected to the inner ring 42 and the outer ring 48, depending on the position of the scale portion 53A. Sensor heads 53B that output the received signals as position information, and each of the measurement axes includes first and second linear encoders that are adjusted in advance in the tangential direction (X′-axis direction) and the Z-axis direction. Therefore, it is not necessary to adjust the position and orientation relationship between the measurement axes of the first and second linear encoders constituting the measurement devices 71A to 71C after being attached to the inner ring 42 and the outer ring 48. Further, since the position and orientation relationship between the measurement axes is adjusted before the measuring devices 71A to 71C are attached to the inner ring 42 and the outer ring 48, the position and orientation relationship can be adjusted and set with high accuracy. Therefore, the positional relationship between the inner ring 42 and the outer ring 48 can be measured with high accuracy by the measuring device. In addition, since each of the first and second linear encoders is adjusted in advance, it is not necessary to adjust after the first and second linear encoders are attached to the inner ring 42 and the outer ring 48. Therefore, the inner ring 42 and the outer ring 48 are relatively driven. using the driving mechanism 41 _{1-41 6,} it is not necessary to adjust the linear encoder, since there is no consume the stroke of the drive mechanism 41 _{1-41 6} for adjustment, after assembling the measuring device Relative driving of the inner ring 42 and the outer ring 48 can be performed in a wide range.

Moreover, according to the mirror holding mechanism of this embodiment and the mirror holding mechanism manufactured by the manufacturing method of this embodiment, the inner ring 42 and the outer ring 48 are driven by the driving mechanisms 41 _{1 to} 41 ₆ , and the measuring devices 71A to 71A Since the relative positional relationship between the inner ring 42 and the outer ring 48 is measured by 71C, the positional relationship between the inner ring 42 and the outer ring 48 can be measured with high accuracy by the measuring devices 71A to 71C. By driving the inner ring 42 with respect to the outer ring 48 by the drive mechanism based on the measurement result, the positional relationship between the two can be adjusted with high accuracy.

  Further, according to the mirror holding mechanism of the present embodiment, the sensor head portion 53B is fixed to the outer ring 48 (fixed side), and the scale portion 53A is fixed to the inner ring 42 (movable side). Since the wiring of the measuring device is not connected, vibration transmission does not occur, and it is possible to prevent the drive accuracy of the inner ring 42 from being lowered by dragging the wiring.

  Further, according to the mirror holding mechanism of the present embodiment, a part (upper end portion) of the scale portion 53A of the measuring devices 71A to 76C is fixed near the portion where the one end portion of the link 110 of the inner ring 42 is fixed. Yes. That is, even if the inner ring 42 is deformed, the inner ring 42 is fixed to a portion that is least affected by the deformation, so that the position / posture of the inner ring 42 can be measured with high precision (and the positions of the mirrors M1 to M6).・ Attitude measurement is possible.

  Further, according to the mirror unit of the present embodiment, the mirrors M1 to M6 are held by the inner ring 42 of the drive unit 92 of the present embodiment, and therefore the inner ring 42 is measured by the measuring devices 71A to 71C that constitute the mirror holding mechanism. The positional relationship between the outer ring 48 and the outer ring 48 can be measured with high accuracy, and the inner ring 42 and the mirror held by the inner ring 42 are driven with respect to the outer ring 48 by the mirror holding mechanism based on the measurement result. Thus, the positional relationship between the inner ring 42 or the mirror and the outer ring 48 can be adjusted with high accuracy.

  In addition, according to the projection optical apparatus of the present embodiment, the mirror unit of the present embodiment is included, and the mirror can be driven over a wide range. By doing so, it is possible to maintain the optical performance high over a long period of time.

  Further, according to the exposure apparatus of the present embodiment, since the projection optical apparatus of the present embodiment capable of maintaining high performance over a long period of time is provided, the transfer of the reticle pattern to the wafer over a long period of time. It is possible to carry out with high precision.

  In the above embodiment, the inner ring 42 and the outer ring 48 are adjusted in a state in which the origin of the sensors of the measuring devices 71A to 76C and the posture relationship between the measurement axes of the first and second linear encoders are adjusted. However, the present invention is not limited to this, and it is sufficient that at least the attitude relationship between the measurement axes of the first and second linear encoders is adjusted.

  In the above embodiment, the case where the linear encoder is employed as the sensor provided in the measuring devices 71A to 76C has been described. However, the present invention is not limited thereto, and a sensor such as a capacitance sensor, an eddy current sensor, or a contact sensor is used. It may be used.

  In the above embodiment, the case where the measuring devices 71A to 71C are separately assembled to the mirror holding mechanism has been described. However, the present invention is not limited to this, and for example, the sensor head unit and the scale unit are fixed. The measurement devices 71A to 71C in the state are integrally coupled with each other in a predetermined positional relationship using ring-shaped coupling members, and the measurement devices are connected to the inner ring and the outer ring while maintaining the coupled state ( It is good also as attaching to a mirror holding mechanism.

  In the above embodiment, the scale and the sensor head are arranged as shown in FIG. 6A. However, the arrangement is not limited to this, and the arrangement shown in FIG. 12 (that is, the first sensor head 59A). And the groove 59d of the second sensor head 59B may be formed on the + B side surface). In this case, the shapes of the first and second scales are simplified.

Further, the first holding member 57 and the second holding member 61 are not limited to those having the special shape described in the embodiment, and the first and second scale portions 55A and 55B are related to the first holding member 57. The first and second sensor heads 59A and 59B can be held with respect to the second holding member 61 as long as the second holding member 61 can be held and can be fixed to the inner ring 42. Any shape can be used as long as it can be fixed to the outer ring 48.

  In the above embodiment, the case where the parallel link mechanism is used as the drive mechanism provided in the mirror holding mechanism has been described. However, the present invention is not limited to this, and other actuators may be used.

  In the above-described embodiment, the case where the mirror holding mechanism adopts the Stewart platform type parallel link mechanism having three parallel link pairs including two parallel links has been described. For example, a parallel link mechanism in which the links are arranged at equal intervals along the outer peripheries of the outer ring 48 and the inner ring 42 may be employed.

  In the above embodiment, each of the six mirrors has been described as being driven in the direction of six degrees of freedom. However, it is sufficient that at least one mirror can be driven. The at least one mirror may be drivable in a two-degree-of-freedom direction, a three-degree-of-freedom direction, a four-degree-of-freedom direction, or a five-degree-of-freedom direction excluding rotation about the Z axis.

  In the above embodiment, the case where all the mirrors in the projection optical device PO are held by the optical member holding device of the present invention has been described. However, one or more mirrors in the projection optical device PO are optical members of the present invention. Even in this case, the mirror can be finely driven with high accuracy. Therefore, the mirror can be finely adjusted in the projection optical PO, and thus the projection optical apparatus PO. Can be adjusted with high accuracy. The mirrors M1 to M5 may be movable and only the mirror M6 may be fixed.

  In the above embodiment, the case where the optical member is a mirror has been described. However, the present invention is not limited to this, and the optical member may be a lens.

In the above embodiment, the case where the EUV light is used as the exposure light and the all-reflection projection optical apparatus including only six mirrors is used has been described as an example, and the present invention is not limited to this. Of course. That is, for example, a VUV light source having a wavelength of 100 to 160 nm as a light source as well as an exposure apparatus provided with a projection optical system (projection optical apparatus) including only four mirrors as disclosed in Japanese Patent Application Laid-Open No. 11-345761. For example, the present invention can be suitably applied to a projection optical system (projection optical apparatus) having 4 to 8 mirrors using an Ar ₂ laser (wavelength 126 nm). In addition, the present invention can be preferably applied to both a refractive projection optical system (projection optical apparatus) including only a lens and a catadioptric projection optical system (projection optical apparatus) including a lens in part. it can.

  In the above embodiment, the case where the optical apparatus of the present invention is employed as a projection optical apparatus constituting the exposure apparatus has been described. However, the present invention is not limited to this, and for example, the optical apparatus of the present invention is used. It may be employed as an illumination optical system. The measurement apparatus of the present invention is not limited to the case where it is used in an exposure apparatus, and is another apparatus that includes a first object and a second object, and the positional relationship between the first object and the second object. Of course, it is also possible to employ in a measuring device.

  In the above embodiment, the case where EUV light having a wavelength of 11 nm is used as exposure light has been described. However, the present invention is not limited to this, and EUV light having a wavelength of 13 nm may be used as exposure light. In this case, in order to secure a reflectance of about 70% with respect to EUV light having a wavelength of 13 nm, it is necessary to use a multilayer film in which molybdenum Mo and silicon Si are alternately laminated as the reflection film of each mirror.

  In the above embodiment, the laser excitation plasma light source is used as the exposure light source. However, the present invention is not limited to this, and any of SOR, betatron light source, discharged light source, X-ray laser, and the like may be used.

  As described above, the measurement apparatus of the present invention is suitable for measuring relative position information of a first object and a second object in a plurality of different directions including the first axis direction and the second axis direction. The method for manufacturing a drive unit according to the present invention is suitable for manufacturing a drive unit that drives a first object with respect to a second object. The drive unit of the present invention is suitable for driving the first object with respect to the second object. Further, the optical unit of the present invention is suitable for being incorporated in a proof optical system of an exposure apparatus or a projection optical apparatus. The optical apparatus of the present invention is suitable for use as an illumination optical system or projection optical apparatus of an exposure apparatus. The exposure apparatus is suitable for transferring a mask pattern onto a photosensitive object.

It is the schematic which shows the exposure apparatus which concerns on one Embodiment. It is a schematic perspective view of the projection optical apparatus of FIG. FIG. 3A and FIG. 3B are diagrams for explaining the arrangement of mirrors constituting the projection optical apparatus. It is a figure for demonstrating the effect | action of the mirror which comprises a projection optical apparatus. It is a perspective view which fractures | ruptures and shows a part of division | segmentation lens barrel 152c. 6A is a perspective view showing the measuring device 71A in FIG. 5 taken out, and FIG. 6B is a perspective view showing the sensor head portion and the scale portion in FIG. 6A separately. is there. It is a disassembled perspective view of the measuring apparatus 71A of FIG. 6 (A). FIG. 8A is a perspective view showing a fixture, and FIG. 8B is a perspective view showing a state where the sensor head portion and the scale portion are fixed by the fixture. It is a flowchart (flow diagram) which shows the process in which a mirror holding mechanism is manufactured. It is a block diagram which shows the control system of one Embodiment of this invention. 6 is a flowchart (flow diagram) illustrating a process in which the projection optical apparatus is manufactured. It is a figure which shows the modification of a measuring device.

Explanation of symbols

10 ... exposure apparatus, 42 ... inner ring (first object), 41 _{1-41 6} ... drive mechanism, 48 ... outer ring (second object), 52 ... barrel, 55A, 55B ... first, second scale part (Detection object), 57 ... first holding member, 59A, 59B ... first and second sensor heads, 61 ... second holding member, 65 ... fixture, 71A to 76C ... measuring device, 92 ... drive Unit (part of optical unit), 110 ... link, EL ... EUV light (energy beam), M1 to M6 ... mirror (optical member, part of optical unit), PO ... projection optical device (optical device), R ... Reticle (mask), W ... wafer (substrate).

Claims (18)

A measuring device that measures relative position information of a plurality of different directions including a first axis direction and a second axis direction of a first object and a second object,
A detection target connected to one of the first and second objects and a signal corresponding to the position of the detection target connected to the other of the first and second objects are output as position information. A first sensor and a second sensor each including a sensor head,
The measuring apparatus according to claim 1, wherein the measurement axes of the first and second sensors are adjusted in advance in the first axis direction and the second axis direction. Each of the sensors has a measurement origin,
The said each sensor head and each said detection target are further adjusted beforehand by the positional relationship which each sensor head outputs the positional information on the said origin as said positional information. Measuring device.   The measuring apparatus according to claim 1, wherein each sensor is a linear encoder. A first holding member that integrally holds the respective detection objects after the adjustment;
The measurement device according to claim 1, further comprising: a second holding member that integrally holds the sensor heads after the adjustment.   The measuring apparatus according to claim 4, further comprising a fixture that fixes a space between the first holding member and the second holding member in the adjusted state. A method of manufacturing a drive unit for driving a first object relative to a second object,
An assembly step of assembling the first object and the second object via a drive mechanism;
A detection target connected to one of the first and second objects, and a signal corresponding to the position of the detection target connected to the other of the first and second objects. An adjustment step of previously adjusting the measurement axes of the first and second sensors respectively including sensor heads that output position information;
A fixing step of fixing the detection object and the sensor head of each of the first and second sensors in the adjusted state;
Connecting a detection target of each sensor to the one object side and connecting each sensor head to the other object side;
A release step of releasing the fixation between the detection object and the sensor head. Each of the sensors has a measurement origin,
In the adjustment step, the positional relationship between each sensor head and each detection object is further adjusted to a positional relationship in which each sensor head outputs the positional information of the origin as the positional information. The manufacturing method of the drive unit of Claim 6. And further including a coupling step of integrally coupling the detection target and the sensor head included in each of the first and second sensors fixed in the fixing step in a predetermined positional relationship.
In the connecting step, the detection object and the sensor head included in each of the first and second sensors are connected to the first and second objects in the integrally coupled state. The manufacturing method of the drive unit of Claim 6 or 7. A first object;
A second object physically separated from the first object;
A drive mechanism for driving the first object relative to the second object;
The detection target of each sensor is connected to one of the first object and the second object, and the sensor head of each sensor is connected to the other. And a driving unit comprising:   The drive unit according to claim 9, wherein the drive mechanism drives the first object in a direction of six degrees of freedom with respect to the second object.   The drive unit according to claim 9 or 10, wherein the drive mechanism is a parallel link mechanism.   The drive unit according to claim 11, wherein the parallel link mechanism includes three link pairs including two links.   The drive unit according to claim 12, comprising three measurement devices corresponding to the three link pairs. An optical member;
An optical unit comprising: a drive unit manufactured by the method for manufacturing a drive unit according to any one of claims 6 to 8, wherein the optical member is held by the first object. An optical member;
An optical unit comprising: the drive unit according to any one of claims 9 to 13, wherein the optical member is held by the first object.   16. The optical unit according to claim 14, wherein a detection target of each sensor is connected to the first object side, and a sensor head of each sensor is connected to the second object side. With a lens barrel;
An optical device comprising: the optical unit according to any one of claims 14 to 16 disposed at a predetermined position in the lens barrel. An exposure apparatus that irradiates a mask with an energy beam and transfers a pattern of the mask onto a substrate,
An exposure apparatus comprising: the optical apparatus according to claim 17 disposed on an optical path of the energy beam from the mask to the substrate.

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