JP2020071274A - Exposure apparatus and method for manufacturing article - Google Patents

Abstract

To provide a technique advantageous for obtaining an enlarged depth of focus in an exposure apparatus that scans and exposes a substrate while inclining an original plate or the substrate with respect to an image plane of a projection optical system.SOLUTION: An exposure apparatus 50 has an illumination optical system IL for illuminating an original plate 17 and a projection optical system PO for projecting a pattern of the original plate onto a substrate 20, and exposes the substrate while scanning the original plate and the substrate under a condition of the original plate or the substrate being inclined with respect to an image plane of the projection optical system. The exposure apparatus has an adjusting unit 21 for adjusting inclination of the original plate or the substrate with respect to the image plane and a control unit 30 for controlling the adjusting unit. The control unit determines the direction of the inclination so as to reduce an error of a latent image to be formed on a shot region between a case when a shot region on the substrate is exposed while the original plate or the substrate is inclined in a first direction and a case when the shot region is exposed while the original plate or the substrate is inclined in a second direction that is an opposite direction to the first direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an exposure apparatus and an article manufacturing method, for example, an exposure apparatus that exposes a substrate in a state where an original plate or a substrate is tilted with respect to an image plane of a projection optical system, and an article for manufacturing an article using the exposure apparatus. It relates to a manufacturing method.

  As a method of increasing the depth of focus in an exposure apparatus, a FLEX (Focus Latitude Enhancement Exposure) method of forming an image of a mask pattern at different positions in the optical axis direction is known. When performing exposure by the FLEX method in the scanning exposure apparatus, scanning is driven with the substrate or mask inclined with respect to the image plane of the projection optical system. In the exposure by the FLEX method, in order to obtain the effect of uniformly increasing the depth of focus on the entire image plane of the projection optical system, the aperture (slit) region of the illumination field stop of the illumination optical system is along the direction orthogonal to the scanning direction. It needs to be symmetrical about a straight line. In the exposure by the FLEX method, since the substrate stage is tilted, when the slit area is asymmetric, the defocus amount changes at each position in the direction orthogonal to the scanning direction, and the effect of evenly increasing the depth of focus within the shot area is achieved. Can't get

  In Patent Document 1, when the mask or the substrate is tilted, the coma aberration generated due to the change in telecentricity between the front side and the back side of the slit is controlled to increase the depth of focus in the shot area. Techniques for making uniform have been proposed.

JP, 2009-164296, A

  At present, the effect of expanding the depth of focus when the exposure by the FLEX method is performed by the scanning exposure apparatus is not sufficient, and improvement is desired.

  According to one aspect of the present invention, an illumination optical system that illuminates an original plate and a projection optical system that projects a pattern of the original plate onto a substrate are provided, and the original plate or the substrate is tilted with respect to an image plane of the projection optical system. An exposure apparatus that exposes the substrate while scanning the original plate and the substrate in a kept state, an adjusting unit that adjusts an inclination of the original plate or the substrate with respect to the image plane, and a control unit that controls the adjusting unit. And a case where the original portion or the substrate is exposed in a shot area on the substrate in a state in which the original plate or the substrate is tilted in the first direction, and the original plate or the substrate is opposite to the first direction. The direction of the inclination is determined so that the error of the latent image formed on the shot area is reduced between the case where the shot area is exposed in a state of being inclined in the second direction. To Optical apparatus is provided.

  According to the present invention, for example, an advantageous technique is provided for obtaining an expanded depth of focus in an exposure apparatus that scans and exposes a substrate by inclining the original plate or the substrate with respect to the image plane of the projection optical system.

FIG. 3 is a diagram showing a configuration of a scanning exposure apparatus in the embodiment. The figure explaining exposure by the FLEX method. The figure which shows the relationship between the shape of a slit area | region and a defocus amount. The figure explaining the calculation method of a defocus coefficient. 6 is a flowchart showing a process of determining the tilt direction of the substrate during FLEX exposure in the embodiment. 6A and 6B are diagrams illustrating a process of determining a tilt direction of a substrate during FLEX exposure according to the embodiment. 6 is a flowchart showing a process of determining the tilt direction of the substrate during FLEX exposure in the embodiment. 6A and 6B are diagrams illustrating a process of determining a tilt direction of a substrate during FLEX exposure according to the embodiment. The graph which shows the example of the aberration with respect to each of several inclination amount of a board | substrate. FIG. 6 is a diagram showing an example of distortion generated by tilting the substrate for each of a plurality of tilt amounts of the substrate. The figure which illustrates the arrangement | positioning of several shot area | region on a board | substrate, and the order of exposure.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following embodiments are merely examples of the practice of the present invention, and the present invention is not limited to the following embodiments. In addition, not all combinations of features described in the following embodiments are essential for solving the problems of the present invention.

<First Embodiment>
FIG. 1 is a diagram showing a schematic configuration of a scanning exposure apparatus 50 in this embodiment. The scanning exposure apparatus 50 is configured to scan and expose the substrate 20 by scanning the original (also referred to as a mask or reticle) 17 and the substrate 20 while projecting the pattern of the original 17 onto the substrate 20 by the projection optical system PO. ing.

  In this specification, the directions are shown in an XYZ orthogonal coordinate system in which the horizontal plane is the XY plane, the axis parallel to the optical axis AX of the projection optical system PO is the Z axis, and the X axis and the Y axis are orthogonal to the Z axis. To take. The directions parallel to the X axis, the Y axis, and the Z axis are the X direction, the Y direction, and the Z direction, respectively.

  In this embodiment, the illumination optical system IL is composed of elements arranged in the optical path from the light source 1 to the collimator lens 16. The light source 1 is, for example, an ArF excimer laser having an oscillation wavelength of about 193 nm or a KrF excimer laser having an oscillation wavelength of about 248 nm, but the type of the light source and the wavelength of light emitted from the light source are not limited in the present invention.

  The light emitted from the light source 1 is guided to the diffractive optical element 3 by the routing optical system 2. Typically, a plurality of diffractive optical elements 3 are mounted in each slot of a turret having a plurality of slots, and any diffractive optical element 3 can be arranged in the optical path by the actuator 4.

  The light emitted from the diffractive optical element 3 is condensed by the condenser lens 5 and forms a diffraction pattern on the diffraction pattern surface 6. By exchanging the diffractive optical element 3 located in the optical path by the actuator 4, the shape of the diffraction pattern can be changed.

  The diffraction pattern formed on the diffraction pattern surface 6 is incident on the mirror 9 after parameters such as the annular ratio and the σ value are adjusted by the prism group 7 and the zoom lens 8. The light flux reflected by the mirror 9 enters the optical integrator 10. The optical integrator 10 can be configured as, for example, a lens array (fly eye).

  The prism 7 group includes, for example, a prism 7a and a prism 7b. When the distance between the prism 7a and the prism 7b is sufficiently small, the prism 7a and the prism 7b can be regarded as an integrated single glass flat plate. The σ value of the diffraction pattern formed on the diffraction pattern surface 6 is adjusted by the zoom lens 8 while maintaining a substantially similar shape, and an image is formed on the incident surface of the optical integrator 10. By separating the positions of the prism 7a and the prism 7b, the annular pattern and the aperture angle of the diffraction pattern formed on the diffraction pattern surface 6 are adjusted.

  The light flux emitted from the optical integrator 10 is condensed by the condenser lens 11 and forms a desired light intensity distribution on the surface 13 conjugate with the original plate 17. The illumination field stop (light-shielding member) 12 is arranged at a position deviated from the surface 13 which is conjugate with the surface on which the original plate 17 is arranged, defines the illumination area of the original plate 17 by the exposure light, and determines the light intensity distribution in the illumination area. Control. More specifically, the light blocking member 12 controls the light intensity distribution of the exposure light so that the light intensity distribution of the original plate 17 and the substrate 20 along the scanning direction becomes trapezoidal. The trapezoidal light intensity distribution is effective for reducing the variation in the integrated exposure amount in the scanning direction due to the fact that the light generated by the light source 1 is pulsed light, that is, has discontinuity.

  The light flux that has passed through the aperture (slit) of the illumination field stop 12 illuminates the original plate 17 via the collimator lens 14, the mirror 15, and the collimator lens 16. The pattern of the original plate 17 is projected by the projection optical system PO onto the substrate 20 held by the substrate stage WS including the tilt stage 19. As a result, a latent image pattern is formed on the photosensitive material on the substrate 20.

  The tilt stage 19 is positioned so that the substrate 20 is scanned while the surface of the substrate 20 held thereby is tilted with respect to the image plane of the projection optical system PO. The tilt of the tilt stage 19 (that is, the tilt of the substrate 20) is adjusted by an adjusting unit 21 including a tilt mechanism. Although the original plate 17 may be tilted instead of tilting the substrate 20, a structure in which the substrate 20 is tilted is adopted here. In the example shown in FIG. 1, the scanning direction is along the Y-axis, and the axis that controls the tilt of the substrate 20 or the original plate 17 for expanding the depth of focus is rotation around the X-axis (ωX).

  The projection optical system PO has a drive mechanism 25 that changes the aberration of the projection optical system PO by moving, rotating, and / or deforming at least one lens 24 of the plurality of lenses forming the projection optical system PO. The drive mechanism 25 includes, for example, a mechanism for moving the lens 24 in a direction along the optical axis AX of the projection optical system PO and an axis parallel to two axes (X axis, Y axis) perpendicular to the optical axis AX. And a mechanism for rotating the lens 24. The sensitivity of the aberration change to the driving of the lens 24 may be previously determined through calculation or actual measurement, and characteristic data (for example, a table) indicating the sensitivity may be stored in the memory 32 of the control unit 30. The control unit 30 can determine the drive amount of the lens 24 based on the characteristic data and drive the lens 24 according to the drive amount.

  The control unit 30 controls each unit of the scanning exposure apparatus 50. The control unit 30 includes a memory 32 that stores programs and data, and executes the scanning exposure by executing the control program stored in the memory 32.

  The FLEX method is a method for improving the contrast and expanding the depth of focus by shifting the focus and performing multiple exposure. When performing scanning exposure by the FLEX method in the scanning exposure apparatus 50, as shown in FIG. 2, the original plate 17 and the substrate 20 are scanned and driven in the directions indicated by the arrows. Hereinafter, the substrate 20 will be described as being driven by scanning. In that case, when the substrate 20 is exposed by the FLEX method, the substrate 20 is scan-driven so that each point of the substrate 20 is defocused → best focus → defocused on the image plane side of the projection optical system PO. For example, the control unit 30 controls the substrate stage WS so that the point through which the optical axis AX on the surface of the substrate 20 passes matches the best focus position of the projection optical system PO. Further, the substrate stage WS is controlled by the control unit 30 so that the substrate 20 has a target inclination.

  Exposure by the FLEX method will be described with reference to FIG. In the exposure by the FLEX method, the traveling direction of the substrate stage is tilted with respect to the best focus plane (BF plane), so that multiple exposure can be continuously performed at a plurality of imaging positions near the BF plane. Here, the tilt amount of the substrate stage and the tilt amount of the substrate stage in the running direction are the same. In order to obtain the effect of uniformly increasing the depth of focus on the entire image plane of the projection optical system PO in such exposure by the FLEX method, as shown in FIG. 3 (A1), the aperture (slit) of the illumination field stop 12 is formed. It is necessary that the area be substantially rectangular. When the slit area is rectangular, the slit width is the same at each position (i1, i2, i3) in the direction (X direction) orthogonal to the scanning direction. In this case, as shown in FIG. 3 (A2), even if the tilt stage 19 tilts the substrate by the tilt amount M, the defocus amount at each position (i1, i2, i3) is made uniform in the shot area. Can be generated (Df1 = Df2 = Df3).

  On the other hand, there may be a shape in which the slit area is asymmetrical with respect to a straight line along the direction orthogonal to the scanning direction for the purpose of correcting the uneven illuminance. For example, as shown in FIG. 3 (B1), the slit region has a shape in which the slit width is not the same at each position (i1, i2, i3) in the direction orthogonal to the scanning direction (hereinafter also referred to as “slit position”). Think In this case, as shown in FIG. 3B2, the defocus amount changes at each position in the shot area due to the tilt of the substrate by the tilt stage 19 (Df1 = Df3 ≠ Df2). In the example of FIG. 3B2, the defocus amount at the position i2 is + Df2 on the + Df side from the tilt axis center, whereas the defocus amounts + Df1 and + Df3 at the positions i1 and i2 are larger. Therefore, it is not possible to obtain the effect of uniformly increasing the depth of focus within the shot area.

  Since the FLEX method continuously performs multiple exposure with a plurality of image forming positions near the best focus plane, an error of a latent image formed on a shot area may occur due to superposition of defocused projected images. Occur. In the exposure apparatus, there are errors that cannot be eliminated even in the optical characteristics of the apparatus (slit asymmetry, telecentricity, image plane) or in the apparatus adjustment state. Furthermore, when performing exposure by the FLEX method, an error due to the tilt of the substrate may occur in the latent image formed on the shot area, and the error may increase. Therefore, the effect of expanding the depth of focus originally expected in the FLEX method cannot be obtained. The present embodiment focuses on such a problem.

In the present embodiment, the control unit 30 controls the tilt direction of the substrate 20 so as to reduce the error of the latent image formed on the shot area between the following cases (A) and (B). Is determined and the adjusting unit 21 is controlled. (A) When the shot area is exposed with the substrate 20 tilted in the first direction.
(B) When the shot area is exposed in a state where the substrate 20 is tilted in the second direction opposite to the first direction.

  Hereinafter, a specific example will be described. The error of the latent image formed on the shot area can be observed as displacement of the latent image, distortion, line width error, and the like. Therefore, the latent image error may be any of the latent image position shift, distortion, and line width error, for example. In the following, it is assumed that the latent image error is specified by the positional deviation of the latent image (hereinafter also referred to as “latent image deviation”).

First, with reference to FIG. 4, a method of calculating a defocus coefficient for calculating the amount of positional deviation will be described. The defocus coefficient is a value that depends on the width of each position in the direction orthogonal to the scanning direction of the slit formed by the illumination field stop 12. In FIG. 4, Ai and Bi represent the distance from the tilt axis center at the slit position i to the slit end. At this time, the defocus coefficient Ki indicating the ratio of the defocus amount at the slit position i is expressed by the following equation.
Ki = Bi / Ai

  Ideally, the projection optical system is expected to have no aberration, but in reality there are aberrations (adjustment residuals) that cannot be adjusted. The influence of this aberration can be observed, for example, as a positional shift of the latent image as shown in FIG. Such misalignment also appears during normal exposure without tilting the substrate. Further, in the exposure by the FLEX method (FLEX exposure) performed with the expectation of increasing the depth of focus, depending on the combination of the tilt amount of the substrate and the asymmetry of the slit width as shown in FIG. ) And (D), a new positional deviation Pm occurs. Due to such positional deviation, the deviation from the ideal image formation increases as if the aberration of the projection optical system increased. Therefore, in the present embodiment, based on the deviation of the latent image during normal exposure in which the shot area is exposed without tilting the substrate and the deviation of the latent image caused by tilting the substrate, the substrate during FLEX exposure Determine the tilt direction.

FIG. 5 shows a flowchart of the process for determining the amount of tilt of the substrate in this embodiment. In S11, the control unit 30 acquires the deviation L (first error) of the latent image when performing normal exposure. In S12, the control unit 30 determines the tilt amount of the latent image formed on the shot region when the shot region is exposed with the substrate tilted in the first direction by α [μrad] as the tilt amount M of the substrate. The resulting shift Pm1 (second error) is obtained. From the deviation Om1 of the latent image caused by the tilt amount M of the substrate at this time and the defocus coefficient Ki, the deviation Pm1 of the latent image theoretically generated from the slit shape is calculated by the following equation.
Pm1 = Ki · Om1

Further, the control unit 30 is formed on the shot area when exposing the shot area with the substrate tilted by α [μrad] in the second direction opposite to the first direction as the tilt amount M of the substrate. The deviation Pm2 (third error) due to the inclination of the latent image is calculated. From the latent image shift Om2 generated by the tilt amount M of the substrate at this time and the defocus coefficient Ki, the latent image shift Pm2 theoretically generated from the slit shape is calculated by the following equation.
Pm2 = Ki · Om2

  FIG. 6B shows a latent image shift Pm1 that occurs when the FLEX exposure is performed with the substrate tilt amount M being tilted by α [μrad] in the + direction (first direction). FIG. 6D shows a latent image shift Pm2 that occurs when FLEX exposure is performed with the substrate tilt amount M tilted by α [μrad] in the − direction (second direction). Thus, the sign of the displacement of the latent image is inverted depending on the direction in which the substrate is tilted.

  The effect of the latent image shift during the actual exposure is a combination of the latent image shift L (first error) due to the adjustment residual and the latent image shift Pm generated during the FLEX exposure. In actual production, it is necessary to reduce the displacement of the latent image in the shot area. Therefore, in S13, the control unit 30 sets the latent image shift L (first error) due to the adjustment residual and the latent image shift Pm1 (second error) when the image is tilted by α [μrad] in the first direction. L + Pm1 (first combining error) obtained by combining is calculated (FIG. 6C). Further, the control unit 30 combines the latent image shift L (first error) due to the adjustment residual and the latent image shift Pm2 (second error) when the image is tilted in the second direction by α [μrad]. L + Pm2 (second synthesis error) is obtained (FIG. 6 (E)). Further, the control unit 30 determines the tilt direction of the substrate based on the result of the comparison between the first combining error and the second combining error. For example, the control unit 30 calculates the defocus amount at each image height in the X direction for each of L + Pm1 (FIG. 6C) and L + Pm2 (FIG. 6E), and detects the deviation of the latent image in the shot area. The tilt direction is determined so that the absolute value becomes small. In S14, the control unit 30 drives the tilt stage 19 according to the determined tilt direction to tilt the substrate.

<Second Embodiment>
In the first embodiment, the latent image error is specified by the positional shift of the latent image formed on the shot area. However, in the second embodiment, the latent image error is caused by the distortion of the latent image formed on the shot area. Identify the error. In the second embodiment, from the viewpoint of distortion, the image height in the X direction is increased due to the defocus amount and the telecentric component that occur when FLEX exposure is performed in an exposure apparatus having an asymmetric slit shape as shown in FIG. 3B2. Consider the shift component generated for each.

  Ideally, it is expected that the lens of the projection optical system has no distortion, but in reality, there is a distortion (adjustment residual) N that cannot be adjusted, as shown in FIG. .. This distortion also appears during normal exposure without tilting the substrate. Further, in the FLEX exposure which is performed with the expectation of increasing the depth of focus, depending on the combination of the tilt amount of the substrate and the asymmetry of the slit width as shown in FIG. 3B2, it is shown in FIGS. 8B and 8D. Distortion Qm as described above is newly generated. Therefore, in this embodiment, the tilt direction of the substrate during FLEX exposure is determined based on the distortion during normal exposure in which the substrate is not tilted and the distortion that occurs due to tilting the substrate.

FIG. 7 shows a flowchart of the process for determining the amount of tilt of the substrate in this embodiment. In S21, the control unit 30 acquires the distortion N during normal exposure. In S22, the control unit 30 calculates the distortion Qm that is theoretically generated by the slit shape from the distortion Rm generated by the amount M of tilt of the substrate and the defocus coefficient Ki by the following formula.
Qm = Ki ・ Rm

  FIG. 8B shows the distortion Qm1 that occurs when the FLEX exposure is performed with the substrate tilt amount M being + β [μrad]. FIG. 8D shows the distortion Qm2 that occurs when the FLEX exposure is performed with the substrate tilt amount M set to −β [μrad]. In this way, the direction of distortion is reversed depending on the direction in which the substrate is tilted.

  The effect of distortion during actual exposure is the sum of the adjustment residual distortion N and the distortion Qm that occurs during FLEX exposure. In actual production, it is necessary to reduce the distortion within the shot. Therefore, in S23, the control unit 30 calculates the distortion of each of N + Qm1 (FIG. 8C) and N + Qm2 (FIG. 8E), and determines the tilt direction so that the absolute value of the distortion in the shot becomes small. To do. In S24, the control unit 30 drives the tilt stage 19 according to the determined tilt direction to tilt the substrate.

<Third Embodiment>
FIG. 9 is a graph showing an example of a latent image error caused by the tilt of the substrate for each of a plurality of tilt amounts of the substrate. In the present embodiment, for example, data according to this graph is stored in the memory 32 of the control unit 30 in advance. The control unit 30 obtains the error Om caused by the set tilt amount M of the substrate from the data stored in the memory 32. The control unit 30 calculates an error Pm, which is theoretically generated from the slit shape, from the obtained error Om and the defocus coefficient Ki by the following equation.
Pm = Ki · Om

  The control unit 30 adds the calculated error Pm to the above-mentioned characteristic data as a lens control parameter. In addition to Pm, the lens control parameter may include, for example, the Z position, the amount of inclination about the X axis, the amount of inclination about the Y axis, and the like. Then, the control unit 30 performs FLEX exposure while driving the lens 24 of the projection optical system PO by the drive mechanism 25 so as to correct the error Pm as the lens control parameter.

<Fourth Embodiment>
FIG. 10 is a diagram showing an example of distortion generated by the tilt of the substrate for each of the plurality of tilt amounts of the substrate. In the present embodiment, for example, the distortion data according to this figure is stored in advance in the memory 32 of the control unit 30. The control unit 30 obtains the distortion Rm caused by the amount M of inclination of the substrate from the distortion data stored in the memory 32. The control unit 30 calculates the distortion Qm, which is theoretically generated from the slit shape, from the calculated distortion Rm and defocus coefficient Ki by the following equation.
Qm = Ki ・ Rm

  The control unit 30 adds the calculated distortion Qm to the above-mentioned characteristic data as a lens control parameter. In addition to Qm, the lens control parameter can include, for example, the Z position, the amount of inclination about the X axis, the amount of inclination about the Y axis, and the like. Then, the control unit 30 performs FLEX exposure while driving the lens 24 of the projection optical system PO by the drive mechanism 25 so as to correct the distortion Qm as the lens control parameter.

<Fifth Embodiment>
In the above-described embodiment, the tilt of the substrate 20 is adjusted so that the error of the latent image is reduced in one shot area. Therefore, the control unit 30 can adjust the inclination of the substrate by the adjustment unit 21 for each of the plurality of shot areas arranged on the substrate 20. Thereby, it is possible to obtain the effect of uniformly increasing the depth of focus within each shot area, and it is possible to improve the exposure accuracy.

  However, adjusting the inclination for each of the plurality of shot areas on the substrate lowers the throughput. Therefore, the control unit 30 adjusts the inclination of the substrate by the adjustment unit 21 for each group of a plurality of shot areas arranged on the substrate 20 in which the exposure order is continuous and the scanning directions are the same, The tilt adjustment state may be fixed within each group. For example, in general, a plurality of shot areas are arranged in a matrix on a substrate, and the scanning direction of each shot area, the exposure order of each shot area, and the movement path of the substrate between the shot areas are predetermined as exposure conditions. ing. FIG. 11 shows an example of a plurality of shot areas arranged in a matrix on the substrate. In scanning exposure, generally, from the viewpoint of throughput, as shown in FIG. 11, the exposure order is set in a snake-like manner from the shot area at the edge of the substrate. In this case, the shot area group in one row is an example of a group in which the exposure order is continuous and the scanning directions are the same. This makes it possible to suppress a decrease in throughput due to the adjustment of the inclination of the substrate.

  In one embodiment, the control unit 30 has, as the exposure control modes, a user-selectable accuracy priority mode that prioritizes exposure accuracy and a throughput priority mode that prioritizes throughput. When the precision priority mode is selected, the adjustment of the inclination of the substrate is performed by the adjustment unit 21 for each of the plurality of shot areas arranged on the substrate 20. On the other hand, when the throughput priority mode is selected, the adjustment of the inclination of the substrate is performed by the adjustment unit 21 for each group of a plurality of shot areas in which the exposure order is continuous and the scanning directions are the same. Within the group, the adjustment state of the inclination of the substrate is fixed.

<Embodiment of article manufacturing method>
The article manufacturing method according to the 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. In the article manufacturing method of the present embodiment, a step of forming a latent image pattern on the photosensitive agent applied to the substrate using the above-mentioned exposure apparatus (step of exposing the substrate), and the latent image pattern is formed in the step. Developing the substrate. Further, the manufacturing method includes other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.). The article manufacturing method of the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article as compared with the conventional method.

IL: illumination optical system, PO: projection optical system, 17: original plate (reticle), RS: original plate stage, 19: tilt stage, 20: substrate, WS: substrate stage, 30: control unit, 32: memory, 50: scanning Exposure equipment

Claims (10)

An illumination optical system for illuminating an original plate and a projection optical system for projecting a pattern of the original plate onto a substrate, and the original plate and the substrate in a state in which the original plate or the substrate is inclined with respect to an image plane of the projection optical system. An exposure apparatus for exposing the substrate while scanning
An adjusting unit for adjusting the inclination of the original plate or the substrate with respect to the image plane,
A control unit for controlling the adjustment unit,
The control unit exposes a shot area on the substrate in a state in which the original plate or the substrate is tilted in a first direction, and a case where the original plate or the substrate is in a second direction opposite to the first direction. The exposure apparatus is characterized in that the tilt direction is determined so that an error in a latent image formed on the shot area is reduced between the case where the shot area is exposed in a state of being tilted. The control unit is
When exposing the shot area in a state where the original plate or the substrate is not tilted, a first error which is an error of a latent image formed on the shot area is acquired,
When the shot area is exposed with the original plate or the substrate tilted in the first direction, a second error which is an error due to the tilt of the latent image formed on the shot area is obtained. ,
When the shot area is exposed with the original plate or the substrate tilted in the second direction, a third error, which is an error caused by the tilt, of the latent image formed on the shot area is obtained. ,
Based on the result of comparison between a first combined error obtained by combining the first error and the second error and a second combined error obtained by combining the first error and the third error, the direction of the tilt is determined. The exposure apparatus according to claim 1, wherein the exposure apparatus is determined. The illumination optical system includes an illumination field stop that defines an illumination area of the original plate,
The controller is formed on the shot area due to the defocus coefficient depending on the width of each position in the direction orthogonal to the scanning direction of the slit formed by the illumination field stop, and the tilt of the substrate. The error of the latent image according to the shape of the slit, which is calculated based on the error of the latent image, is obtained as the second error or the third error. Exposure equipment.   The control unit performs exposure while driving a lens included in the projection optical system so as to correct the second error or the third error. The exposure apparatus described.   The control unit obtains the second error and the third error based on data of an error caused by the inclination of the substrate for each of a plurality of inclination amounts of the substrate. Exposure equipment.   The exposure apparatus according to claim 1, wherein the control unit adjusts the inclination by the adjustment unit for each of a plurality of shot areas arranged on the substrate. ..   The control unit adjusts the inclination by the adjustment unit for each group in which a plurality of shot areas arranged on the substrate have a continuous exposure order and the same scanning direction, and within each group. 6. The exposure apparatus according to claim 1, wherein the adjustment state of the tilt is fixed.   As the exposure control mode, the control unit has a precision priority mode that prioritizes exposure precision and a throughput priority mode that prioritizes throughput. When the precision priority mode is selected, the control unit is arranged on the substrate. When the inclination is adjusted by the adjusting unit for each of the plurality of shot areas and the throughput priority mode is selected, the exposure order of the plurality of shot areas is continuous and the scanning directions are the same. 6. The exposure apparatus according to claim 1, wherein the adjustment unit adjusts the inclination for each group, and the adjustment state of the inclination is fixed in each group. ..   9. The exposure apparatus according to claim 1, wherein the latent image error is one of a latent image position shift, distortion, and line width error. Exposing a substrate using the exposure apparatus according to any one of claims 1 to 9;
Developing the exposed substrate in the step,
Including,
An article manufacturing method, comprising manufacturing an article from the developed substrate.