Exposure apparatus and method for manufacturing article

Abstract

To provides an advantageous technique for improving exposure accuracy in a scanning exposure using a FLEX method.SOLUTION: An exposure apparatus for performing scanning exposure of a substrate by projecting a pattern of an original onto the substrate includes: a plurality of change sections that change a relative inclination amount between a surface of the substrate and an image-forming surface of the pattern on the original; and a control section that controls the scanning exposure with the relative inclination amount set to a target inclination amount by the plurality of change sections. The control section: assigns a target inclination amount to each of the plurality of change sections so that the relative inclination amount becomes the target inclination amount; and causes the relative inclination amount to be changed by the plurality of change sections based on the inclination amount assigned to each of the plurality of change sections.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an exposure apparatus and a method for manufacturing an article. [Background technology]

[0002] As a method for increasing the focal depth in an exposure apparatus, the FLEX (Focus Latitude Enhancement Exposure) method has been proposed, in which the pattern of an original (mask, reticle) is imaged at a different position in the optical axis direction (see Patent Document 1). When performing scanning exposure using the FLEX method in an exposure apparatus, the substrate is scanned while the substrate surface and the imaging plane of the original pattern are inclined relative to each other. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-71274 A Summary of the Invention [Problem to be solved by the invention]

[0004] In exposure apparatuses, for example, a substrate stage including a coarse stage movable in the XY directions and a fine stage capable of holding a substrate and moving on the coarse stage is often used. When performing scanning exposure using the FLEX method using such a substrate stage, the relative tilt amount between the substrate surface and the image plane of the original pattern can be changed by tilting the fine stage with respect to the coarse stage. However, in order to improve the exposure accuracy in scanning exposure using the FLEX method, it is required to increase the relative tilt amount between the substrate surface and the image plane of the original pattern, and it is not sufficient to change the relative tilt amount by using the substrate stage alone.

[0005] Therefore, an object of the present invention is to provide an advantageous technique for improving the exposure accuracy in scanning exposure using the FLEX method. [Means for solving the problem]

[0006] In order to achieve the above object, an exposure apparatus according to one aspect of the present invention projects a pattern of an original onto a substrate, of exposure do an exposure apparatus, comprising: a plurality of change units for changing a relative tilt amount between a surface of the substrate and an imaging plane of a pattern of the original; of and a control unit for controlling the 、 Based on the gradient amount assigned to each of the plurality of modification portions I The plurality of change units Control the The relative tilt amount is changed.

[0007] Further objects and other aspects of the present invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings. Effect of the Invention

[0008] According to the present invention, for example, it is possible to provide an advantageous technique for improving the exposure accuracy in scanning exposure using the FLEX method. [Brief description of the drawings]

[0009] [Figure 1] Schematic diagram showing the configuration of an exposure apparatus [Diagram 2] FIG. 13 is a diagram showing an example of changing the relative tilt amount between the substrate surface and the imaging surface in scanning exposure using the FLEX method. [Diagram 3] Schematic diagram showing a configuration example of a substrate stage [Figure 4] FIG. 13 is a diagram showing a change in the gap between the coarse movement stage and the fine movement stage in the substrate stage. [Diagram 5] Schematic diagram of fine stage tilt measurement by the measurement unit [Figure 6] Flowchart showing scanning exposure in the first embodiment [Figure 7] Flowchart showing scanning exposure in the second embodiment DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0011] First Embodiment A first embodiment of the present invention will be described. FIG. 1 is a schematic diagram showing the configuration of an exposure apparatus 100 of this embodiment. The exposure apparatus 100 is a scanning exposure apparatus used, for example, in a manufacturing process of a semiconductor device, and exposes a substrate 106 by a step-and-scan method to transfer a pattern of an original 102 onto the substrate. The exposure apparatus 100 of this embodiment includes, for example, an illumination optical system 101, an original stage 103 that holds the original 102, a projection optical system 104, a substrate stage 200 that holds the substrate 106, and a controller 108. The controller 108 is formed of, for example, a computer having a CPU, a memory, etc., and controls each component according to a program to control the scanning exposure of the substrate 106.

[0012] In the following, two axes that are orthogonal to each other in a plane parallel to the plane along which the substrate stage 200 moves (for example, the base surface 107a) are defined as the X-axis direction and the Y-axis direction, and the direction perpendicular to the plane is defined as the Z-axis direction. In the following description, when the term "X-axis direction" is mentioned, it is defined to include the +X direction and the -X direction. The same is true for the "Y-axis direction" and the "Z-axis direction." In addition, the scanning direction of the substrate 106 in scanning exposure is defined as the Y-axis direction (+Y direction or -Y direction).

[0013] The illumination optical system 101 shapes light emitted from a light source (not shown) and illuminates the original 102 with the shaped light. A pattern (e.g., a circuit pattern) to be transferred onto a substrate 106 is formed on the original 102. The original 102 is made of, for example, quartz glass, and is also called a mask or a reticle. The original stage 103 is a drive mechanism for driving the original 102 in each of a plurality of axial directions (e.g., six axial directions: X-axis, Y-axis, Z-axis, ωX-axis, ωY-axis, and ωZ-axis), and is configured to be movable while holding the original 102. The original stage 103 is configured to be movable on a mount 105 supported by a base frame 107.

[0014] The projection optical system 104 is supported by a support mechanism SM, and projects an image of the pattern of the original 102 illuminated with light from the illumination optical system 101 onto the substrate 106 at a predetermined projection magnification. The support mechanism SM may be configured by a base frame 107 and a mount 105 supported by the base frame 107 and movable in each of a plurality of axial directions (for example, six axial directions of the X-axis, the Y-axis, the Z-axis, the ωX-axis, the ωY-axis, and the ωZ-axis) relative to the base frame 107. The substrate 106 is a wafer made of, for example, single crystal silicon, with a resist (photosensitive agent) applied on its surface. The substrate stage 200 has a chuck for holding the substrate 106, and is a driving mechanism for driving the substrate 106 in each of a plurality of axial directions (for example, six axial directions of the X-axis, the Y-axis, the Z-axis, the ωX-axis, the ωY-axis, and the ωZ-axis), and may be configured to be movable while holding the substrate 106. In this embodiment, the substrate stage 200 is movable on a base surface 107a of the base frame 107 in the XY directions.

[0015] The original stage 103, the mount 105, and the substrate stage 200 are provided with an actuator (not shown) and a position measurement sensor (not shown) to form a unit that can be positioned and driven. Each of the original stage 103, the mount 105, and the substrate stage 200 has a degree of freedom in six axial directions, namely, the X-axis direction, the Y-axis direction, the Z-axis direction, and the rotation directions of each axis (ωX direction, ωY direction, ωZ direction), and can be driven in the six axial directions by an actuator (not shown).

[0016] In the exposure apparatus 100, the original 102 held by the original stage 103 and the substrate 106 held by the substrate stage 200 are respectively disposed at optically conjugate positions (the object plane and image plane of the projection optical system 104) via the projection optical system 104. A control unit 108 drives the original stage 103 and the substrate stage 200 to relatively scan in the scanning direction (the Y-axis direction in this embodiment) at a speed ratio according to the projection magnification of the projection optical system 104 while synchronizing them with each other. This makes it possible to transfer the pattern of the original 102 onto the substrate 106.

[0017] [Scanning exposure using the FLEX method] In the exposure apparatus 100, the FLEX (Focus Latitude Enhancement Exposure) method may be applied in the scanning exposure of the substrate 106. The FLEX method is a method for improving contrast and expanding the depth of focus by performing multiple exposure with shifting the focus. In the FLEX method, scanning exposure is performed in a state in which the surface of the substrate 106 and the imaging surface of the pattern of the original 102 (hereinafter, simply referred to as the imaging surface) are inclined relative to each other. FIG. 2 shows an example of changing the relative inclination amount (relative inclination amount) between the surface of the substrate 106 and the imaging surface in the scanning exposure using the FLEX method. In the FLEX method, for example, as shown in FIG. 2(a), the substrate 106 is tilted by the substrate stage 200, so that the substrate 106 is scanned and driven in a state in which the surface of the substrate 106 and the imaging surface are inclined relatively in the ωX direction (rotation direction around the X axis). This allows each point (each position) on the substrate 106 to progress through the projection optical system 104 in the order of defocus → best focus → defocus, enabling multiple exposures to be performed at multiple image positions that change continuously near the image plane (best focus plane) of the projection optical system 104.

[0018] However, in order to improve the exposure accuracy in the scanning exposure by the FLEX method, it is required to increase the relative tilt amount between the surface of the substrate and the imaging surface, and it is not sufficient to change the relative tilt amount by the substrate stage. Therefore, in the exposure apparatus 100 of the present embodiment, a plurality of change units are provided to change the relative tilt amount between the surface of the substrate 106 and the imaging surface individually. Then, the target tilt amount is assigned (distributed) to each of the plurality of change units so that the target tilt amount is achieved by causing each of the plurality of change units to change the relative tilt amount. Such allocation of the target tilt amount is preferably performed when the target tilt amount is larger than the relative tilt amount that can be changed individually by each of the plurality of change units. Also, the target tilt amount can be defined as a target value of the relative tilt amount between the surface of the substrate and the imaging surface to achieve the exposure accuracy required for the scanning exposure by the FLEX method.

[0019] In this embodiment, the multiple change units can include at least two of the substrate stage 200 (first change unit) that holds the substrate 106, the original stage 103 (second change unit) that holds the original 102, and the support mechanism SM (third change unit) that supports the projection optical system 104. As described above, the support mechanism SM may be understood as a mechanism consisting of the mount 105 and the base frame 107. Note that, hereinafter, the relative tilt amount between the surface of the substrate 106 and the imaging plane may be referred to as the "FLEX amount," and the target tilt amount may be referred to as the "target FLEX amount."

[0020] The substrate stage 200 is configured to hold the substrate 106 and to be able to adjust the tilt of the substrate 106, and the amount of FLEX is changed by tilting the substrate 106. In the example shown in Fig. 2(a), the substrate stage 200 tilts the substrate 106 in the -ωX direction, thereby tilting the surface of the substrate 106 relative to the imaging plane. In this way, the amount of FLEX can be controlled by controlling the amount of tilt of the substrate 106 in the ±ωX directions using the substrate stage 200.

[0021] The support mechanism SM is configured to support the projection optical system 104 and adjust the inclination of the projection optical system 104, and changes the FLEX amount by tilting the projection optical system 104. The support mechanism SM is configured to change the inclination (posture) of the projection optical system 104 by tilting the mount 105 with respect to the base frame 107 by an actuator (not shown). In the example shown in FIG. 2(b), the support mechanism SM tilts the projection optical system 104 in the +ωX direction, thereby relatively inclining the surface of the substrate 106 and the image forming surface. In this way, the support mechanism SM controls the inclination amount of the projection optical system 104 in the ±ωX directions, thereby controlling the FLEX amount. Note that the direction of the relative inclination between the surface of the substrate 106 and the image forming surface is the same when the projection optical system 104 is tilted in the +ωX direction and when the substrate stage 200 is tilted in the -ωX direction.

[0022] The original stage 103 is configured to hold the original 102 and to be able to adjust the tilt of the original 102, and the FLEX amount is changed by tilting the original 102. In the example shown in FIG. 2(c), the original stage 103 tilts the original 102 in the -ωX direction, thereby tilting the surface of the substrate 106 and the imaging surface relatively. In this way, the FLEX amount can be controlled by controlling the tilt amount of the original 102 in the ±ωX directions using the original stage 103. However, when the tilt (posture) of the original 102 is changed relative to the projection optical system 104, aberration changes may occur. This may become an optical constraint in scanning exposure using the FLEX method.

[0023] Here, the projection optical system 104 includes an optical system that projects an inverted image of the pattern formed on the original 102 and an optical system that projects an upright image. In the former case, the direction of relative inclination between the surface of the substrate 106 and the imaging surface is the same when the original 102 is tilted in the -ωX direction by the original stage 103 and when the substrate 106 is tilted in the -ωX direction by the substrate stage 200. In the latter case, the direction of relative inclination between the surface of the substrate 106 and the imaging surface is the same when the original 102 is tilted in the +ωX direction by the original stage 103 and when the substrate 106 is tilted in the -ωX direction by the substrate stage 200.

[0024] Also, in this embodiment, an example has been shown in which the FLEX amount is controlled by controlling the tilt (posture) of the substrate 106, the original 102, and the projection optical system 104. That is, the substrate stage 200, the original stage 103, and the support mechanism SM have been exemplified as a change unit that changes the FLEX amount. However, this is not limited to this, and another unit capable of controlling the FLEX amount may be provided. For example, a unit capable of controlling the FLEX amount by driving an optical element that constitutes the projection optical system 104 may be provided in the exposure apparatus 100 as a change unit that changes the FLEX amount.

[0025] [Example of change section configuration] Next, a configuration example of each change unit that changes the FLEX amount will be described. Each change unit includes a mechanism having a first member and a second member supported by the first member, and can change the FLEX amount by driving the mechanism so as to tilt the second member relative to the first member. FIG. 3 is a schematic diagram showing a configuration example of a substrate stage 200 as an example of a change unit. The substrate stage 200 can be composed of a coarse movement stage 201 (first member) that has poor positioning accuracy but can be driven (moved) with a large stroke and large thrust, and a fine movement stage 202 (second member) that has a small stroke but high positioning accuracy. The fine movement stage 202 holds the substrate 106, is supported by the coarse movement stage 201, and is configured to be movable on the coarse movement stage 201. The coarse movement stage 201 and the fine movement stage 202 are equipped with an actuator and a position measurement sensor (not shown), and are a unit that can be positioned and driven. As an example, the coarse movement stage 201 is configured to be driven with two degrees of freedom in the X-axis direction and the Y-axis direction. Furthermore, the fine movement stage 202 is configured to be drivable with six degrees of freedom in the X-axis direction, the Y-axis direction, the Z-axis direction, and the rotational directions of each axis (ωX direction, ωY direction, ωZ direction).

[0026] As shown in FIG. 3, the substrate stage 200 of this embodiment is configured such that a convex portion provided on the lower surface of the fine stage 202 is disposed (inserted) into a concave portion provided on the upper surface of the coarse stage 201. The coarse stage 201 and the fine stage 202 are driven and positioned in a non-contact state by an air bearing or the like so that a gap (gap) is formed between them. FIG. 3 shows the positional relationship between the coarse stage 201 and the fine stage 202 in the normal state, and the coarse stage 201 and the fine stage 202 in the normal state are disposed such that their center of gravity positions (center positions) in the Y-axis direction are both located at the target position Y0. The normal state refers to, for example, a state in which the FLEX amount (tilt amount of the substrate 106) is set to zero and no acceleration or deceleration is being driven. The gap amount GAP between the coarse stage 201 and the fine stage 202 can be defined as the distance in the Y-axis direction between the concave portion of the coarse stage 201 and the convex portion of the fine stage 202. The gap amount GAP may be defined as the amount of drive until the coarse movement stage 201 and the fine movement stage 202 come into contact with each other when the fine movement stage 202 is driven in the -Y direction relative to the coarse movement stage 201 from the state shown in FIG. The gap amount GAP may be measured by a sensor provided on the substrate stage 200.

[0027] 4 is a diagram showing changes in the gap amount GAP between the coarse movement stage 201 and the fine movement stage 202 in the substrate stage 200. This gap amount GAP changes depending on the inclination (posture) and / or movement of the fine movement stage 202 relative to the coarse movement stage 201.

[0028] FIG. 4(a) shows a state in which the fine movement stage 202 is tilted by an amount of tilt θ in the direction of rotation (ωX direction) around the X-axis with respect to the coarse movement stage 201, centered on the center of rotation O. Compared to the example of FIG. 3, the position of the center of rotation O in the Y-axis direction is the target position Y0, but the gap amount GAP is reduced in FIG. 4(a). In scanning exposure using the FLEX method, when the fine movement stage 202 is tilted and driven, the gap amount GAP is reduced as shown in FIG. 4(a) even if the center of rotation O is located at the target position Y0. The reduction amount of the gap amount GAP (hereinafter, sometimes referred to as the gap reduction amount) can be calculated by geometric calculation based on the attitude of the fine movement stage 202 before and after tilting the fine movement stage 202 in the ωX direction with respect to the coarse movement stage 201. Specifically, if the center of rotation O is the origin, the position of portion A of fine movement stage 202 in the state shown in Fig. 3 is (Y, Z) = (Y1, Z1), and the position of portion A in the state shown in Fig. 4(a) is (Y, Z) = (Y2, Z2), then position Y2 can be calculated using equation (1). The amount of gap reduction can be calculated as the difference between position Y1 and position Y2 using equation (2). Y2 = cosθ·Y1 + sinθ·Z1 (1) Y1-Y2=Y1-(cosθ·Y1+sinθ·Z1) (2)

[0029] FIG. 4(b) shows a state in which the position of the fine movement stage 202 in the Y-axis direction relative to the coarse movement stage 201 has changed due to a control deviation that occurs when the substrate stage 200 is driven. The control deviation is the deviation between a target position and a current position, and generally tends to increase as the scanning speed (acceleration / deceleration) of the substrate stage 200 increases. In the state of FIG. 4(b), the gap amount GAP is smaller than in the state of FIG. 3. Specifically, the position of the center of gravity of the coarse movement stage 201 in the Y-axis direction is the current position Y0 relative to the target position Y0. c The center of gravity of the fine movement stage 202 in the Y-axis direction is displaced to the current position Y f At this time, the control deviation E c , and the control deviation E of the fine movement stage 202 fis calculated by the formulas (3) to (4), respectively. The amount of gap reduction is calculated by the control deviation E c and the control deviation E of the fine movement stage 202 f It is calculated as the difference between E c =Y0-Y c (3) E f =Y0-Y f (4) E f -E c =(Y0-Y f )-(Y0-Y c )=Y c -Y f (5)

[0030] In the substrate stage 200, servo control can be performed so that the relative positions of the coarse movement stage 201 and the fine movement stage 202 do not change, but when the substrate stage 200 is driven in the XY directions (for example, the Y-axis direction), a control deviation as described above can occur. Therefore, even when the fine movement stage 202 is not tilted relative to the coarse movement stage 201, as shown in Fig. 4(b), the gap amount GAP can decrease due to the control deviation occurring in each of the coarse movement stage 201 and the fine movement stage 202. In other words, as described above, a decrease in the gap amount GAP (i.e., a gap reduction amount) can also occur due to the difference between the control deviation of the coarse movement stage 201 and the control deviation of the fine movement stage 202.

[0031] In this way, when the substrate 106 is tilted and driven by the substrate stage 200 in scanning exposure using the FLEX method, a gap reduction amount due to the amount of tilt of the fine movement stage 202 relative to the coarse movement stage 201 and a gap reduction amount due to a control deviation may occur. Therefore, depending on these gap reduction amounts, the coarse movement stage 201 and the fine movement stage 202 may come into contact (interfere). Therefore, in scanning exposure using the FLEX method, a mechanical constraint condition (first constraint condition) may be set to limit the tilt of the fine movement stage 202 relative to the coarse movement stage 201 so as to avoid contact between the coarse movement stage 201 and the fine movement stage 202.

[0032] Similarly to the substrate stage 200, the original stage 103 may also include a coarse movement stage (first member) and a fine movement stage (second member), with a gap formed between the coarse movement stage and the fine movement stage. Therefore, when the original 102 is tilted and driven by the original stage 103 in scanning exposure using the FLEX method, a gap reduction amount caused by the tilt amount of the fine movement stage relative to the coarse movement stage and a gap reduction amount caused by a control deviation may occur. Therefore, a mechanical constraint condition (first constraint condition) may also be set for the original stage 103 to limit the tilt of the fine movement stage relative to the coarse movement stage so as to avoid contact between the coarse movement stage and the fine movement stage.

[0033] Furthermore, the mount 105 and the base frame 107 in the support mechanism SM are also configured as a mechanism including a first member and a second member, similar to the coarse movement stage 201 and the fine movement stage 202 in the substrate stage 200 described above. In the support mechanism SM, the mount 105 may correspond to the first member, and the base frame 107 may correspond to the second member. As an example, the support mechanism SM may be configured such that a convex portion provided on the lower surface of the mount 105 is disposed (inserted) in a concave portion provided on the upper surface of the base frame 107, and a gap (gap) is formed between them. When the mount 105 is tilted with respect to the base frame 107 in scanning exposure, a gap reduction amount due to the tilt amount may occur. In addition, a gap reduction amount due to a control deviation may occur due to a driving reaction force of the original stage 103 and / or the substrate stage 200. Therefore, in the support mechanism SM, a mechanical constraint condition (first constraint condition) for limiting the tilt of the mount 105 with respect to the base frame 107 may be set so as to avoid contact between the mount 105 and the base frame 107. It should be noted that the “gap reduction amount caused by the tilt amount” in the support mechanism SM can be defined as the gap reduction amount caused by the tilt amount of the mount 105 relative to the base frame 107.

[0034] Another example of a mechanical constraint is a constraint on the measurement range of the measurement unit 300 that measures the tilt of the second member (the fine movement stage in the substrate stage 200 and the original stage 103, and the mount 105 in the support mechanism SM). For example, in the substrate stage 200, if the fine movement stage 202 is tilted too much in the ωX direction relative to the coarse movement stage 201, the tilt of the fine movement stage 202 may fall outside the measurement range of the measurement unit 300. FIG. 5 is a schematic diagram of the measurement of the tilt of the fine movement stage 202 by the measurement unit 300. In FIG. 5, a laser interferometer is exemplified as the measurement unit 300, and a laser beam indicated by a dashed line is output from the measurement unit 300, reflected by the surface (upper surface) of the fine movement stage 202, and enters the measurement unit 300. The measuring section 300 can use the laser beam reflected by the surface of the fine movement stage 202 and incident thereon to determine the inclination of the fine movement stage 202 (for example, the height of the surface of the fine movement stage 202).

[0035] 5(a) shows a state where the tilt of the fine movement stage 202 is within the measurement range of the measurement unit 300. In the state of FIG. 5(a), light reflected by the surface of the fine movement stage 202 enters the measurement unit 300, so that the measurement unit 300 can measure the tilt of the fine movement stage 202 (the height of the surface). On the other hand, FIG. 5(b) shows a state where the tilt of the fine movement stage 202 is out of the measurement range of the measurement unit 300. In the state of FIG. 5(b), the fine movement stage 202 is tilted too much, so that the light reflected by the surface of the fine movement stage 202 does not enter the measurement unit 300, so that the measurement unit 300 cannot measure the tilt of the fine movement stage 202 (the height of the surface). The master stage 103 and the support mechanism SM are also similar to those of the substrate stage 200. Therefore, in scanning exposure using the FLEX method, a mechanical constraint condition (second constraint condition) for restricting the inclination of the second member relative to the first member so that it falls within the measurement range of the measurement unit 300 can be set.

[0036] As described above, constraint conditions for changing the FLEX amount can be set for each of the multiple modification units (e.g., the substrate stage 200, the original stage 103, and the support mechanism SM). Therefore, in the exposure apparatus 100 of this embodiment, when allocating a target FLEX amount to each modification unit, the constraint conditions set for each modification unit can be used. In other words, the target FLEX amount can be allocated to each of the multiple modification units based on the constraint conditions set for each modification unit. Below, an example of allocating a target FLEX amount to each modification unit will be described.

[0037] [Example 1] Fig. 6 is a flowchart showing scanning exposure in the first embodiment (Example 1). The flowchart in Fig. 6 may include steps (S101 to S104) of allocating a target FLEX amount to a plurality of change units based on constraints set for each change unit. The target FLEX amount may be set in advance depending on, for example, the accuracy (exposure accuracy, transfer accuracy) of transferring the pattern of the original 102 onto the substrate. Moreover, each step in the flowchart in Fig. 6 may be executed by the control unit 108.

[0038] In step S101, the control unit 108 obtains the maximum amount of gap reduction caused by control deviation for each of the multiple change units (substrate stage 200, original stage 103, and support mechanism SM). The maximum amount of gap reduction caused by control deviation may be understood as the maximum amount of "gap reduction caused by control deviation" that may occur due to the scanning speed (including acceleration and deceleration) of the substrate 106 and original 102 used in scanning exposure. The purpose of this step S101 is to confirm the amount of gap reduction caused by control deviation that may occur when each change unit is actually driven for scanning. Below, the "maximum amount of gap reduction caused by control deviation" for the substrate stage 200, original stage 103, and support mechanism SM is respectively referred to as A W , A R , A M It is sometimes written as:

[0039] For example, the control unit 108 acquires (measures) the target position and the current position for each change unit while performing the scan drive with the FLEX amount set to zero. As a result, as described above with reference to FIG. 4(b), the "gap reduction amount caused by the control deviation" can be obtained by the formulas (3) to (5). Note that the scan drive here is a drive that does not involve exposure of the substrate, and may be understood as a drive that imitates the scan drive of each unit in the scan exposure. In addition, in the case where a sensor that measures the gap amount GAP is provided, the control unit 108 may obtain the maximum value of the gap reduction amount caused by the control deviation based on the measurement result of the sensor. Furthermore, in the case where the maximum value of the gap reduction amount caused by the control deviation is measured in advance and stored in a storage unit (memory), the control unit 108 may obtain information indicating the maximum value of the gap reduction amount caused by the control deviation from the storage unit.

[0040] In step S102, the control unit 108 sets the amount of gap reduction caused by the amount of tilt for each of the multiple change units (substrate stage 200, original stage 103, and support mechanism SM). As described above with reference to FIG. 4(a), the "amount of gap reduction caused by the amount of tilt" for the substrate stage 200 can be calculated by geometric calculation using equations (1) and (2) from the attitudes of each change unit before and after driving. The "amount of gap reduction caused by the amount of tilt" for the original stage 103 and support mechanism SM can also be calculated using a similar method. Below, the "maximum amount of gap reduction caused by the amount of tilt" for the substrate stage 200, original stage 103, and support mechanism SM will be referred to as B W , B R , B M It is sometimes written as:

[0041] In step S103, the control unit 108 sets a constraint condition for the gap amount GAP for each change unit. In this embodiment, a mechanical constraint condition (first constraint condition) for limiting the inclination of the second member relative to the first member so as to avoid contact between the first member and the second member is described as the constraint condition for the gap amount GAP. The following Table 1 shows the constraint condition (first constraint condition) for the gap amount GAP and the items required for it.

[0042] [Table 1]

[0043] The "FLEX amount" item in Table 1 is a variable indicating the FLEX amount (change amount) to be changed by each change unit. The FLEX amounts (change amounts) for the substrate stage 200, the original stage 103, and the support mechanism SM are respectively represented as F W , F R , F M In addition, the item "Maximum amount of gap reduction caused by control deviation" in Table 1 is the value obtained in step S101 above (A W , A R , A M The item "Gap reduction amount due to tilt amount" in Table 1 is the variable (B W , B R , B M ) where the gap reduction amount B due to the inclination amount is W is the FLEX amount F allocated in step S104 described later. W This is the amount of gap reduction when the substrate 106 is tilted by the substrate stage 200 so as to generate the gap reduction amount B W is the FLEX amount F W Similarly, the gap reduction amount B R is the FLEX amount F R is a function of the gap reduction amount B M is the FLEX amount F M is a function of .

[0044] In addition, the "gap amount constraint" in Table 1 indicates the first constraint as described above. W , G R , G M "A" indicates the gap amount GAP in normal state for the substrate stage 200, the original stage 103, and the support mechanism SM. The normal gap amount GAP is the gap amount GAP when the FLEX amount is zero and no acceleration or deceleration is being performed (i.e., in the state shown in FIG. 3). W +B W " is the FLEX amount F W It means the maximum value of the total gap reduction amount when the substrate 106 is tilted by the substrate stage 200 and scanned and exposed so as to generate a gap reduction amount G. The total gap reduction amount is the sum (combination) of the "gap reduction amount due to the tilt amount" and the "gap reduction amount due to the control deviation." Therefore, "G W >(A W +B W In the case of "G )", scanning exposure can be performed without contact between the coarse movement stage 201 (first member) and the fine movement stage 202 (second member). W ≦(A W +B W )”, there is a high possibility that the coarse movement stage 201 (first member) and the fine movement stage 202 (second member) will come into contact with each other during scanning exposure. W >(A W +B W The FLEX amount F of the substrate stage 200 is set so as to satisfy the first constraint. W Similarly, for the master stage 103 and the support mechanism SM, R >(A R +B R )" and "G M >(A M +B M The FLEX amount F of the master stage 103 is set so as to satisfy the first constraints. R and the FLEX amount F of the support mechanism SM M is determined.

[0045] In step S104, the control unit 108 allocates (distributes) a target FLEX amount to each of the multiple change units based on the constraint conditions set in step S103. That is, the control unit 108 determines the FLEX amount to be changed for each of the substrate stage 200, the original stage 103, and the support mechanism SM. The target FLEX amount required for scanning exposure is F all Then, the control unit 108 determines whether the total of the FLEX amounts changed by each change unit is equal to the target FLEX amount F all So that "F all =F W +F R +F M ". Next, in step S105, the control unit 108 performs scanning exposure while controlling each modification unit (substrate stage 200, original stage 103, support mechanism SM) based on the FLEX amount assigned to each modification unit in step S104. That is, in step S104, the control unit 108 assigns a target FLEX amount to each modification unit so that the relative tilt amount between the surface of the substrate 106 and the imaging surface becomes the target FLEX amount (target tilt amount). Then, based on the FLEX amount (tilt amount) assigned to each modification unit, the control unit 108 controls the scanning exposure to be performed with each modification unit setting the relative tilt amount to the target FLEX amount.

[0046] Here, the allocation (distribution) of the target FLEX amount to each of the multiple change units can be performed based on a preset allocation condition. In this embodiment, an example will be described in which a condition related to the accuracy of changing the FLEX amount (i.e., driving accuracy) is used as the allocation condition. The driving accuracy can be defined as the maximum value of the control deviation during scanning driving. As an example, it is assumed that the maximum value of the control deviation during scanning driving is smallest in the order of the substrate stage 200, the original stage 103, and the support mechanism SM. In this case, the control unit 108 allocates the target FLEX amount to the substrate stage 200, the original stage 103, and the support mechanism SM. First, the maximum FLEX amount that satisfies the constraint condition (e.g., the first constraint condition) of the substrate stage 200 is allocated to the substrate stage 200. Next, the maximum FLEX amount that satisfies the constraint condition (e.g., the first constraint condition) of the original stage 103 is allocated to the original stage 103. Then, the remaining FLEX amount is allocated to the support mechanism SM within a range that satisfies the constraint condition (e.g., the first constraint condition) of the support mechanism SM. Incidentally, if the target FLEX amount cannot be achieved even if the maximum FLEX amount that satisfies the constraints of the support mechanism SM is allocated, the shortage of the FLEX amount is not executed.

[0047] [Example 2] In the first embodiment, an example was described in which the target FLEX amount was assigned to each of the multiple change units based on the constraint condition (first constraint condition) of the gap amount GAP. In the second embodiment, an example was described in which the constraint condition (second constraint condition) of the measurement range and the constraint condition (third constraint condition) of the optical aberration were further added, and the target FLEX amount was assigned to each of the multiple change units based on the first to third constraint conditions. Table 2 below shows the constraint conditions (first to third constraint conditions) of each change unit in the second embodiment, and the items required therefor. Note that the second embodiment basically follows the first embodiment, and the items other than those described below are as described in the first embodiment. In the second embodiment, all of the first to third constraint conditions are used when assigning the target FLEX amount to each of the multiple change units, but this is not limited thereto, and at least one of the first to third constraint conditions may be used.

[0048] [Table 2]

[0049] The item "ωX drive amount" in Table 2 is the drive amount when tilting the second member in the ωX direction relative to the first member so as to generate a FLEX amount in each variable portion. For example, the ωX drive amount X of the substrate stage 200 W is the FLEX amount F W In other words, the ωX driving amount X W is the FLEX amount F W The driving amount ωX of the original stage 103 is a function of R , and the ωX drive amount X of the support mechanism SM M Regarding the substrate stage 200, the ωX driving amount X W It is the same as ωX drive amount X R is the FLEX amount F R is a function of ωX, and the driving amount X M is the FLEX amount F M is a function of .

[0050] The "Constraints on the Measurement Range" in Table 2 indicates the mechanical constraints (second constraints) for restricting the inclination of the second member relative to the first member so as to fall within the measurement range of the measurement unit 300. The lower limit of the measurement range in the ωX direction of the measurement unit 300 provided on the substrate stage 200, the original stage 103, and the support mechanism SM is set as S W1 , S R1 , S M1 , the upper limit is S W2 , S R2 , S M2 In this case, "S W1 <X W W2 The FLEX amount F of the substrate stage 200 is set so as to satisfy the second constraint condition. W Similarly, "S R1 <X R R2 The FLEX amount F of the master stage 103 is set so as to satisfy the second constraint. R was decided, and "S M1 <X M <S​​M2 The FLEX amount F of the support mechanism SM is set so as to satisfy the second constraint. M is determined.

[0051] The "Optical Aberration Constraint" in Table 2 indicates the constraint (third constraint) for keeping the optical aberration caused by the change in the FLEX amount within the allowable range. For example, when the original 102 is tilted in the ωX direction by the original stage 103, the optical aberration caused in the image of the pattern of the original 102 may change accordingly. Therefore, the ωX drive amount X of the original stage 103 is changed so that the optical aberration falls within the allowable range. R The lower limit of the ωX drive of the original stage 103 for keeping the optical aberration within the allowable range can be set to O R1 , the upper limit O R2 In this case, "O R1 <X R <O R2 The FLEX amount F of the master stage 103 is set so as to satisfy the third constraint. R The allowable range of optical aberration can be set in advance depending on the accuracy (exposure accuracy, transfer accuracy) of transferring the pattern of the original 102 onto the substrate.

[0052] In the second embodiment, a target FLEX amount is assigned to each change unit based on the constraints shown in Table 2. Specifically, the FLEX amount F of the substrate stage 200 W and the FLEX amount F of the support mechanism SM M is determined so as to satisfy the first and second constraints. R is determined so that the first to third constraints are satisfied.

[0053] [Example 3] In the first embodiment, an example was described in which a condition related to the accuracy of changing the FLEX amount (driving accuracy) is used as an allocation condition, and a target FLEX amount is allocated to each change unit in descending order of driving accuracy. In the third embodiment, an example is described in which a target FLEX amount is allocated to each change unit according to the ratio of driving accuracy. Note that the third embodiment basically follows on from the first embodiment, and the matters other than those described below are as described in the first embodiment. In the third embodiment, as described in the second embodiment, at least one of the first to third constraints may be used when allocating a target FLEX amount to each of a plurality of change units.

[0054] For example, the reciprocals of the maximum control deviations during scanning drive of the substrate stage 200, the original stage 103, and the support mechanism SM are respectively set as α W , α R , α M In this case, the control unit 108 sets the target FLEX amount F all Of these, "(F all ×α W ) / (α W +α R +α M )" corresponds to the amount of FLEX W Similarly, the control unit 108 assigns "(F all ×α R ) / (α W +α R +α M )" corresponds to the amount of FLEX R Assigned to original stage 103 as "(F all ×α M ) / (α W +α R +α M )" FLEX amount F M to the support mechanism SM.

[0055] [Example 4] In the fourth embodiment, an example will be described in which a condition related to the exposure performance obtained by changing the FLEX amount is used as an allocation condition, and a target FLEX amount is allocated to each change unit based on the exposure performance. Note that the fourth embodiment basically follows on from the first embodiment, and is as described in the first embodiment except for the matters described below. In the fourth embodiment, the "condition related to the driving accuracy" described in the first and third embodiments may be further used as an allocation condition. That is, at least one of the "condition related to the driving condition" and the "condition related to the exposure performance" may be used as an allocation condition. Furthermore, in the fourth embodiment, as described in the second embodiment, at least one of the first to third constraint conditions may be used when allocating the target FLEX amount to each of the multiple change units.

[0056] For example, the results of scanning exposure are obtained for each of the cases where a specific FLEX amount is assigned only to the substrate stage 200, where the specific FLEX amount is assigned only to the original stage 103, and where the specific FLEX amount is assigned only to the support mechanism SM. The specific FLEX amount may be understood as a provisional FLEX amount that is arbitrarily set. The results of scanning exposure include, for example, distortion and / or overlay accuracy of a pattern formed on a substrate, and are used as exposure performance. Then, based on the result of comparing the exposure performances, the target FLEX amount F is determined in order of the highest exposure performance. all As an example, if the exposure performance is highest in the order of the substrate stage 200, the support mechanism SM, and the original stage 103, the control unit 108 assigns the target flex amount to the substrate stage 200, the support mechanism SM, and the original stage 103 in that order. First, the target flex amount F all Among these, the maximum FLEX amount that satisfies the constraints of the substrate stage 200 is allocated to the substrate stage 200. Next, the maximum FLEX amount that satisfies the constraints of the support mechanism SM is allocated to the support mechanism SM. Then, the remaining FLEX amount is allocated to the original stage 103 within a range that satisfies the constraints of the original stage 103.

[0057] As described above, the exposure apparatus 100 of the first embodiment includes a plurality of change units (substrate stage 200, original stage 103, support mechanism SM) that can each change the FLEX amount. Then, a target FLEX amount is assigned to each of the plurality of change units so that the target FLEX amount is achieved by causing each of the plurality of change units to change the FLEX amount. This increases the FLEX amount that can be realized in the exposure apparatus 100, and allows scanning exposure using the FLEX method to be performed with higher accuracy.

[0058] <Second embodiment> A second embodiment of the present invention will be described. In this embodiment, an example of controlling scanning exposure with priority given to a specific item will be described. The specific items include exposure accuracy and throughput. The control unit 108 of this embodiment can include an exposure accuracy priority mode and a throughput priority mode as control modes of scanning exposure. The exposure accuracy priority mode is a mode in which the FLEX amount is increased with priority (for example, maximized) so as to improve the exposure accuracy. On the other hand, the throughput priority mode is a mode in which the scanning speed (acceleration / deceleration) of the original 102 and the substrate 106 in scanning exposure is increased (for example, maximized) so as to improve the throughput. The control unit 108 controls scanning exposure according to a control mode selected by the user from the exposure accuracy priority mode and the throughput priority mode. Note that this embodiment basically inherits the first embodiment, and is as described in the first embodiment except for the matters described below.

[0059] 7 is a flowchart showing scanning exposure in the second embodiment. Each step in the flowchart in FIG.

[0060] In step S201, the control unit 108 determines whether the control mode selected by the user is the exposure accuracy priority mode or the throughput priority mode. For example, the control unit 108 can determine whether the exposure accuracy priority mode or the throughput priority mode has been selected by the user based on information input by the user via a user interface of the exposure apparatus 100. If the exposure accuracy priority mode has been selected by the user, the process proceeds to step S202, and if the throughput priority mode has been selected by the user, the process proceeds to step S206.

[0061] Steps S202 to S205 show the process in the exposure accuracy priority mode. Here, the FLEX amount of each change unit can be determined so that the target FLEX amount (i.e., the sum of the FLEX amounts changed by the multiple change units) is maximized and the constraints of each change unit are satisfied.

[0062] In step S202, the control unit 108 sets constraint conditions for each change unit. This step S202 corresponds to steps S101 to S103 in the flowchart of FIG. 6 described in the first embodiment, and the constraint conditions are as described in the first embodiment. Next, in step S203, the control unit 108 allocates the target FLEX amount to each change unit based on the constraint conditions set in step S202. This step S203 corresponds to step S104 in the flowchart of FIG. 6 described in the first embodiment, and the distribution method of the target FLEX amount is as described in the first embodiment.

[0063] In step S204, the control unit 108 determines whether the target FLEX amount is maximized. For example, the control unit 108 can determine whether the target FLEX amount is maximized by determining whether the constraints of each change unit can be satisfied when the target FLEX amount is further increased. As an example, the control unit 108 can determine that the target FLEX amount is maximized when it determines that the substrate stage 200 will not satisfy the first constraint when the target FLEX amount is further increased, that is, the coarse movement stage 201 and the fine movement stage 202 will come into contact with each other. In this case, the control unit 108 proceeds to step S210. On the other hand, when the control unit 108 determines that the substrate stage 200 satisfies the first constraint even if the target FLEX amount is further increased, it determines that the target FLEX amount is not maximized, increases the target FLEX amount in step S205, and then proceeds to step S203. Here, the increase amount of the target FLEX amount in step S205 can be arbitrarily set using experiments, simulations, and the like.

[0064] Steps S206 to S209 show the process in the throughput priority mode. Here, the FLEX amount of each variable part can be determined so that the scanning speed (acceleration / deceleration) of the original 102 and the substrate 106 in the scanning exposure is maximized and the constraints of each variable part are satisfied.

[0065] In step S206, the control unit 108 sets constraint conditions for each change unit. This step S206 corresponds to steps S101 to S103 in the flowchart of FIG. 6 described in the first embodiment, and the constraint conditions are as described in the first embodiment. Next, in step S207, the control unit 108 allocates the target FLEX amount to each change unit based on the constraint conditions set in step S202. This step S207 corresponds to step S104 in the flowchart of FIG. 6 described in the first embodiment, and the distribution method of the target FLEX amount is as described in the first embodiment.

[0066] In step S208, the control unit 108 judges whether the scanning speed is maximized. For example, the control unit 108 can judge whether the scanning speed is maximized by judging whether the constraint conditions of each change unit can be satisfied when the scanning speed is further increased. As an example, the control unit 108 can judge that the scanning speed is maximized when it judges that the substrate stage 200 will not satisfy the first constraint condition when the scanning speed is further increased, that is, the coarse movement stage 201 and the fine movement stage 202 will come into contact with each other. In this case, the control unit 108 proceeds to step S210. On the other hand, when the control unit 108 judges that the substrate stage 200 satisfies the first constraint condition even if the scanning speed is further increased, it judges that the scanning speed is not maximized, increases the scanning speed in step S209, and then proceeds to step S207. Here, the increase amount of the scanning speed in step S209 can be arbitrarily set using experiments, simulations, and the like.

[0067] In step S210, the control unit 108 executes scanning exposure. In the scanning exposure in step S201, the FLEX amount of each change unit that was last determined in step S203 or step S207 can be applied.

[0068] As described above, in the second embodiment, scanning exposure is performed using a control mode selected by the user from the exposure accuracy priority mode and the throughput priority mode. This makes it possible to select and execute either an increase in the FLEX amount or an increase in the scanning speed, which are in a trade-off relationship, according to the user's request.

[0069] <Embodiments of the method for manufacturing an article> The method for manufacturing an article according to an embodiment of the present invention is suitable for manufacturing an article such as a microdevice such as a semiconductor device or an element having a fine structure. The method for manufacturing an article according to this embodiment includes a step of forming a latent image pattern on a photosensitive agent applied to a substrate using the above-mentioned exposure apparatus (a step of exposing the substrate) and a step of developing (processing) the substrate on which the latent image pattern has been formed in this step. Furthermore, this manufacturing method includes other well-known steps (oxidation, film formation, deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.). The method for manufacturing an article according to this embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article compared to conventional methods.

[0070] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0071] 100: exposure apparatus, 101: illumination optical system, 102: original, 103: original stage, 104: projection optical system, 105: mount, 106: substrate, 107: base frame, 200: substrate stage, SM: support mechanism

Claims

1. 1. An exposure apparatus that projects a pattern of an original onto a substrate to expose the substrate, comprising: a plurality of change units for changing a relative tilt amount between the surface of the substrate and an imaging plane of the pattern of the original; A control unit that controls the plurality of change units; Equipped with The exposure apparatus, wherein the control unit controls the plurality of change units based on an amount of tilt assigned to each of the plurality of change units, thereby changing the relative amount of tilt.

2. a projection optical system that projects the pattern of the original onto the substrate; 2. The exposure apparatus of claim 1, wherein the multiple change units include at least two of a first change unit that changes the relative tilt amount by tilting the substrate, a second change unit that changes the relative tilt amount by tilting the original, and a third change unit that changes the relative tilt amount by tilting the projection optical system.

3. the first change unit is a substrate stage that holds the substrate and is capable of adjusting a tilt of the substrate, the second change unit is an original stage that holds the original and is capable of adjusting a tilt of the original, 3. The exposure apparatus according to claim 2, wherein the third change unit is a support mechanism that supports the projection optical system and is capable of adjusting the tilt of the projection optical system.

4. An exposure apparatus as described in any one of claims 1 to 3, characterized in that the control unit controls the scanning exposure of the substrate while the relative tilt amount is set to a target tilt amount by the multiple modification units.

5. The exposure apparatus described in Claim 4, characterized in that the control unit changes the relative tilt amount by assigning the target tilt amount to each of the multiple modification units and controlling the multiple modification units.

6. The exposure apparatus described in Claim 5, characterized in that the control unit assigns the target tilt amount to each of the multiple modification units when the target tilt amount is greater than the relative tilt amount that can be changed individually by each of the multiple modification units.

7. 7. The exposure apparatus according to claim 5, wherein each of the plurality of change units includes a mechanism having a first member and a second member supported by the first member, and changes the relative tilt amount by tilting the second member with respect to the first member.

8. The exposure apparatus according to claim 7, wherein the control unit assigns the target tilt amount to each of the multiple modification units so that a first constraint condition for limiting the tilt of the second member relative to the first member is satisfied to avoid contact between the first member and the second member during the scanning exposure.

9. Each of the plurality of change units includes a measurement unit that measures the inclination of the second member, 9. The exposure apparatus according to claim 7, wherein the control unit assigns the target tilt amount to each of the multiple change units so that a second constraint condition for limiting the tilt of the second member within the measurement range of the measurement unit is satisfied.

10. An exposure apparatus according to any one of claims 5 to 9, characterized in that the control unit assigns the target tilt amount to each of the multiple change units so that a third constraint condition for keeping optical aberration caused by changing the relative tilt amount within an acceptable range is satisfied.

11. the control unit assigns the target tilt amount to each of the plurality of change units based on an assignment condition for assigning the target tilt amount to each of the plurality of change units; 11. The exposure apparatus according to claim 5, wherein the allocation conditions include at least one of a condition related to accuracy with which the relative tilt amount is changed, and a condition related to exposure performance obtained by changing the relative tilt amount.

12. 12. The exposure apparatus according to claim 4, wherein the control unit determines the relative tilt amount to be changed by each of the multiple change units so that a sum of the relative tilt amounts changed by the multiple change units is maximized.

13. 12. The exposure apparatus according to claim 4, wherein the control unit determines the relative tilt amount to be changed by each of the multiple change units so that acceleration / deceleration of the substrate during the scanning exposure is maximized.

14. 1. An exposure method for projecting a pattern of an original onto a substrate and exposing the substrate, comprising the steps of: a changing step of changing a relative tilt amount between the surface of the substrate and an imaging plane of the pattern of the original by a plurality of changing units; an exposure step of exposing the substrate in a state where the relative tilt amount is changed by the plurality of change units; having The exposure method, wherein in the changing step, the plurality of change units are controlled based on tilt amounts assigned to the respective plurality of change units to change the relative tilt amount.

15. an exposure step of exposing a substrate using the exposure method according to claim 14; a processing step of processing the substrate exposed in the exposure step, A method for manufacturing an article, comprising the steps of: manufacturing an article from the substrate processed in the processing step.

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