Method of generation, method of exposure, exposure apparatus, method of manufacturing articles, and program

Abstract

This technology offers advantages in terms of productivity in generating baseline information. [Solution] A generation method for generating spacing information indicating the distance between optical axes in a plurality of scopes that detect marks on a substrate in different ways, using a first mark and a second mark on a substrate, includes: a measurement step of performing a measurement process to detect marks with the plurality of scopes and measure the spacing using the first mark on a first substrate; a prediction step of predicting the spacing obtained in the measurement process using the first mark on the first substrate based on the result of measuring the spacing using the first mark on a second substrate different from the first substrate and state information indicating the state of elements that cause the spacing to vary; and a decision step of deciding whether or not to perform the measurement process using the second mark on the first substrate based on the spacing measured in the measurement step and the spacing predicted in the prediction step.

Description

Technical Field

[0001] The present invention relates to a generation method, an exposure method, an exposure apparatus, an article manufacturing method, and a program.

Background Art

[0002] As one of the apparatuses used in manufacturing processes (lithography processes) such as semiconductor devices and liquid crystal displays, there is an exposure apparatus that exposes a substrate by projecting a pattern of a reticle onto the substrate through a projection optical system. In order to transfer the pattern of the reticle onto the substrate with high accuracy, it is required to accurately align (align) the reticle and the substrate. Therefore, before exposing the substrate, the alignment marks on the substrate and the reticle are detected (imaged) by a scope, and the positions of the alignment marks are measured.

[0003] There are roughly two types of detection methods for alignment marks. One detection method is a method of detecting the alignment marks on the substrate and the reticle through a projection optical system, and is sometimes called a Through The Mirror (TTM) method. Another detection method is a method of detecting only the alignment marks on the substrate without passing through a projection optical system, and is sometimes called an Off Axis method. The exposure apparatus is provided with a scope (alignment scope) that employs the through-the-mirror method and a scope (off-axis scope) that employs the off-axis format, and these scopes are each operated with a role.

[0004] The measured value of the position of the alignment mark obtained by detecting the alignment mark on the substrate with an off-axis scope is corrected based on interval information (so-called baseline information) indicating the interval between the optical axis of the alignment scope and the optical axis of the off-axis scope. The baseline information is generated, for example, by performing a measurement process (so-called baseline measurement) of measuring the interval by detecting the same alignment mark on the substrate with the alignment scope and the off-axis scope.

[0005] Incidentally, the distance between the optical axis of the alignment scope and the optical axis of the off-axis scope can fluctuate over time due to, for example, the effects of heat from exposure light and / or the effects of driving the stage, etc. Therefore, it is necessary to perform baseline measurements and regenerate baseline information in accordance with the fluctuations in this distance. Patent Document 1 describes a method for changing the baseline measurement interval based on the baseline fluctuation information obtained as a result of the measurement and the estimated baseline fluctuation information value each time a baseline measurement is performed on the substrate. Patent Document 2 also describes a method for determining whether to perform baseline measurements and baseline amount correction based on the amount of thermal expansion of the original plate due to exposure light. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2006-41015 [Patent Document 2] Japanese Patent Publication No. 2005-64371 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Baseline information can be generated using the alignment marks detected by the off-axis scope from among multiple alignment marks on the substrate. However, in recent years, there has been a trend to increase the number of alignment marks on a substrate in order to improve the accuracy of overlaying the master pattern onto the substrate. In this case, performing baseline measurements for all of the alignment marks in question may be disadvantageous in terms of productivity (throughput).

[0008] Therefore, the objective is to provide a technology that is advantageous in terms of productivity in generating baseline information. [Means for solving the problem]

[0009] To achieve the above objective, a generation method as one aspect of the present invention is a generation method for generating spacing information indicating the spacing between optical axes in a plurality of scopes that detect marks on a substrate in different ways, using a first mark and a second mark on a substrate, the method comprising: a measurement step of performing a measurement process to detect marks with the plurality of scopes and measure the spacing using the first mark on a first substrate; a prediction step of predicting the spacing obtained in the measurement process using the first mark on the first substrate based on the result of measuring the spacing using the first mark on a second substrate different from the first substrate and state information indicating the state of elements that cause the spacing to vary; and a decision step of deciding whether or not to perform the measurement process using the second mark on the first substrate based on the spacing measured in the measurement step and the spacing predicted in the prediction step.

[0010] Further objects or other aspects of the present invention will be revealed below by preferred embodiments described with reference to the accompanying drawings. [Effects of the Invention]

[0011] According to the present invention, for example, it is possible to provide a technology that is advantageous in terms of productivity in generating baseline information. [Brief explanation of the drawing]

[0012] [Figure 1] A schematic diagram showing an example of the configuration of an exposure apparatus in this embodiment. [Figure 2] Diagram showing examples of mark placement on the original plate and circuit board. [Figure 3] Flowchart showing a method for generating baseline information in one embodiment [Figure 4] This diagram shows how markings on a circuit board are detected using an alignment scope and / or off-axis scope. [Modes for carrying out the invention]

[0013] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims. While the embodiments describe multiple features, not all of these features are essential to the invention, and the features may be combined in any way. Furthermore, in the attached drawings, identical or similar configurations are given the same reference numerals, and redundant descriptions are omitted.

[0014] In this specification and the accompanying drawings, directions are indicated in an XYZ coordinate system with the substrate surface as the XY plane. The directions parallel to the X, Y, and Z axes in the XYZ coordinate system are defined as the X direction, Y direction, and Z direction, respectively, and the rotations around the X, Y, and Z axes are defined as θX, θY, and θZ, respectively. Control and driving (movement) related to the X, Y, and Z axes refer to control or driving (movement) related to the direction parallel to the X, Y, and Z axes, respectively. Furthermore, control or driving related to the θX, θY, and θZ axes refer to control or driving related to rotation around the axis parallel to the X, Y, and Z axes, respectively.

[0015] The following describes an exposure apparatus EXP according to one embodiment of the present invention. The exposure apparatus EXP is a lithography apparatus that forms patterns on a substrate (wafer, plate) and is used to manufacture semiconductor devices, flat panel displays (FPDs), and the like. The exposure apparatus EXP can transfer the pattern of a master plate (mask, reticle) onto a substrate by performing an exposure process that projects the pattern of a master plate onto the substrate via a projection optical system and exposes the substrate. The exposure process is performed for each of a plurality of shot regions on the substrate, and the pattern of the master plate can be transferred to each shot region.

[0016] The exposure apparatus EXP of this embodiment is an exposure apparatus for manufacturing flat panel displays, and is a step-and-scan type exposure apparatus (so-called scanner) that transfers the pattern of the original plate onto the substrate while relatively scanning the original plate and the substrate. However, the exposure apparatus EXP may be a step-and-repeat type exposure apparatus (so-called stepper) that transfers the pattern of the original plate onto the substrate while fixing the position of the original plate.

[0017] FIG. 1 is a schematic diagram showing a configuration example of the exposure apparatus EXP of this embodiment. The exposure apparatus EXP may include an illumination optical system 1, an original plate stage 2, a projection optical system 4, a substrate stage 9, and a control unit 12.

[0018] The illumination optical system 1 includes lenses, mirrors, etc., and illuminates the original plate 3 held by the original plate stage 2 with light (exposure light) having a uniform illuminance distribution. The illumination optical system 1 of this embodiment shapes the light emitted from a light source (not shown) into slit light having a predetermined cross-sectional shape (for example, a rectangular shape or an arc shape), and illuminates a part (illumination area) of the original plate 3 with the slit light. The light source may include, for example, a mercury lamp and an elliptical mirror.

[0019] The original plate stage 2 is configured to hold and drive the original plate 3 on which the pattern to be transferred to the substrate 8 is formed. The original plate stage 2 of this embodiment may be configured to drive the original plate 3 in the X direction, Y direction, and rotation direction (θZ direction). The original plate 3 is disposed on the object plane of the projection optical system 4.

[0020] The projection optical system 4 projects the pattern image of the original plate 3 illuminated by the illumination optical system 1 onto the substrate 8. The projection optical system 4 of this embodiment has a plane mirror 5, a concave mirror 6, and a convex mirror 7. The light from the original plate 3 is reflected in the order of the upper part of the plane mirror 5, the upper part of the concave mirror 6, the convex mirror 7, the lower part of the concave mirror 6, and the lower part of the plane mirror 5, and forms an image on the substrate 8. The projection optical system 4 may be any of an equal magnification system, an enlargement system, and a reduction system.

[0021] The substrate stage 9 holds and drives the substrate 8. The substrate stage 9 of the present embodiment can be configured to drive the substrate 8 in the X direction, Y direction, Z direction, rotation direction (θZ direction), and tilt directions (θX direction, θY direction). The substrate 8 is disposed on the image plane of the projection optical system 4.

[0022] The control unit 12 is constituted by a computer (information processing apparatus) including a processor such as a CPU (Central Processing Unit) and a storage unit such as a memory, and comprehensively controls each part of the exposure apparatus EXP. The control unit 12 of the present embodiment controls the exposure process for each of a plurality of shot regions on the substrate 8, and also controls the generation process of baseline information described later. Further, the control unit 12 controls the driving of the reticle stage 2 and the substrate stage 9 based on the positions and / or angles of the reticle stage 2 and the substrate stage 9 measured by a position sensor such as an interferometer or an encoder. Thereby, the positions and / or angles of the reticle 3 and the substrate 8 can be indirectly controlled.

[0023] Here, the exposure apparatus EXP is provided with a plurality of scopes (detection units) that detect the marks on the substrate 8 by different methods. Each of the plurality of scopes detects an alignment mark (hereinafter, may be simply referred to as a mark) used for aligning the reticle 3 and the substrate 8. In the exposure apparatus EXP of the present embodiment, an alignment scope 10 (first scope) and an off-axis scope 11 (second scope) are provided as the plurality of scopes.

[0024] The alignment scope 10 is a through-the-mirror (TTM) type scope that detects the marks 14 on the substrate 8 via the projection optical system 4. The alignment scope 10 detects the marks 13 on the original plate 3 and the marks 14 on the substrate 8 via the projection optical system 4 in order to measure the relative position between the marks 13 on the original plate 3 and the marks 14 on the substrate 8. The alignment scope 10 in this embodiment has an image sensor that images the marks 13 on the original plate 3 and the marks 14 on the substrate 8, and outputs the images of the marks 13 and 14 obtained by the image sensor to the control unit 12. As a result, the control unit 12 can control the alignment of the original plate 3 and the substrate 8 (i.e., the positioning of the original plate 3 and the substrate 8) based on the relative positions of the marks 13 and 14 in the image.

[0025] The off-axis scope 11 is an off-axis scope that detects the marks 14 on the substrate 8 without going through the projection optical system 4. The off-axis scope 11 detects only the marks 14 on the substrate 8 in order to measure the position of the marks 14 on the substrate 8, and does not detect the marks on the master plate 3. The off-axis scope 11 of this embodiment has an image sensor that images the marks 14 on the substrate 8, and outputs the image of the marks 14 obtained by the image sensor to the control unit 12. As a result, the control unit 12 can control the alignment of the master plate 3 and the substrate 8 (i.e., the positioning of the master plate 3 and the substrate 8) based on the position of the marks 14 in the image and baseline information described later.

[0026] The exposure apparatus EXP may be provided with a drive mechanism 15 that drives the alignment scope 10 to move its detection field (imaging field) on the substrate 8. It may also be provided with a drive mechanism 16 that drives the off-axis scope 11 to move its detection field (imaging field) on the substrate 8. By using these drive mechanisms 15-16, the positional relationship between the detection field of the alignment scope 10 and the detection field of the off-axis scope 11 on the substrate 8 can be adjusted.

[0027] Next, examples of mark placement on the master plate 3 and substrate 8 will be described. Figure 2 shows examples of mark placement on the master plate 3 and substrate 8. Figure 2(a) shows an example of the placement of multiple marks 13 on the master plate 3, and Figure 2(b) shows an example of the placement of marks 14 on the substrate 8. In this embodiment, the substrate 8 is provided with multiple (four) shot regions 8a on which the pattern of the master plate 3 is transferred, and multiple marks 14 are similarly placed in the multiple shot regions 8a.

[0028] The original plate 3 has three marks 13 positioned along the X direction at the top and bottom of the Y direction, and two marks 13 positioned along the X direction in the center of the Y direction. In other words, the original plate 3 has a total of eight marks 13. In Figure 2(a), the eight marks 13 on the original plate 3 are labeled M1 to M8. The marks M1 to M8 on the original plate 3 can be classified into marks M1 to M6, which are positioned in the left and right columns in the X direction, and marks M7 to M8, which are positioned in the center column in the X direction. Hereafter, marks M1 to M6 will be referred to as "outer marks" and marks M7 to M8 will be referred to as "inner marks".

[0029] Furthermore, each shot area 8a of the substrate 8 has three marks 14 positioned along the X direction at the top and bottom in the Y direction, and two marks 14 positioned along the X direction in the center in the Y direction. In other words, each shot area 8a of the substrate 8 has a total of eight marks 14. In Figure 2(b), the eight marks 14 on the substrate 8 (shot area 8a) are labeled P1 to P8. The marks P1 to P8 on the substrate 8 are positioned at locations corresponding to the positions (projected positions) of the marks M1 to M8 on the master plate 3. The marks P1 to P8 on the substrate 8 can be classified into marks P1 to P6, which are positioned in the left and right columns in the X direction, and marks P7 to P8, which are positioned in the central column in the X direction, similar to the marks M1 to M8 on the master plate 3. Hereafter, marks P1 to P6 will be referred to as "outer marks" and marks P7 to P8 as "inner marks".

[0030] When aligning the master plate 3 and the substrate 8 (each shot area 8a), the outer marks M3-M4 located in the center of the master plate 3 in the Y direction and the outer marks P3-P4 located in the center of the substrate 8 in the Y direction are detected by the alignment scope 10. In addition, the outer marks P1-P2, P5-P6 and inner marks P7-P8 located at the top and bottom of the substrate 8 in the Y direction are detected by the off-axis scope 11. The detection of marks M3-M4 and P3-P4 by the alignment scope 10 and the detection of marks P1-P2 and P5-P8 by the off-axis scope 11 may be performed in parallel.

[0031] The detection results (e.g., image data) from the alignment scope 10 and the off-axis scope 11 are supplied to the control unit 12. Based on the detection results from the alignment scope 10, the control unit 12 determines the relative positions of each outer mark M3 to M4 of the master plate 3 and the corresponding outer marks P3 to P4 of the substrate 8. The control unit 12 also determines the positions of each outer mark P1 to P2, P5 to P6 and each inner mark P7 to P8 of the substrate 8 based on the detection results from the off-axis scope 11 and baseline information. Specifically, the control unit 12 corrects the positions of each mark P1 to P2, P5 to P8 of the substrate 8 calculated from the detection results from the off-axis scope 11 based on the baseline information. This makes it possible to determine the positions of each mark P1 to P2, P5 to P8 of the substrate 8 with respect to the optical axis of the alignment scope 10. By aligning the master plate 3 and the substrate 8 based on the positions of these outer marks, the control unit 12 can accurately transfer the pattern of the master plate 3 to the substrate 8 (each shot area 8a) during the exposure process.

[0032] Here, baseline information refers to spacing information indicating the distance between the optical axes of the alignment scope 10 and the off-axis scope 11 (the so-called baseline). The baseline may fluctuate over time due to, for example, the effects of heat from exposure light and / or the effects of driving the stage, etc. Therefore, it is necessary to regenerate the baseline information in accordance with the fluctuations in the baseline. For example, baseline information is generated by performing a measurement process (so-called baseline measurement) in which the same marks on the substrate 8 are detected by the alignment scope 10 and the off-axis scope 11 and the baseline is measured. In this embodiment, baseline information can be generated using at least some of the marks P1 to P2, P5 to P8 that are detected by the off-axis scope 11 from among a plurality of marks P1 to P8 on the substrate 8.

[0033] In recent years, there has been a trend to increase the number of marks on the substrate 8 in order to improve the accuracy of superimposing the pattern of the master plate 3 onto the substrate 8 (each shot area 8a). In the example in Figure 2(b), inner marks P7 to P8 have been added to the outer marks P1 to P6 that were conventionally provided on the substrate 8. In this case, performing baseline measurements on all of the target marks P1 to P2 and P5 to P8 detected by the off-axis scope 11 may be disadvantageous in terms of productivity (throughput).

[0034] Therefore, in this embodiment, when generating baseline information using the first and second marks of the substrate 8, the decision of whether or not to perform baseline measurement using the second mark is made based on the difference between the measured baseline value and the predicted baseline value when using the first mark. If the difference is greater than or equal to a threshold, baseline measurement is performed using the second mark; if the difference is less than the threshold, baseline measurement using the second mark is omitted. Depending on the difference, this may shorten the time required for baseline measurement using the second mark, which can be advantageous in terms of productivity. Here, the first mark may be the outer marks P1-P2 and P5-P6 of the substrate 8, and the second mark may be the inner marks P7-P8 of the substrate 8.

[0035] Next, the method for generating baseline information (generation process) in this embodiment will be described with reference to Figures 3 and 4. Figure 3 is a flowchart of the baseline information generation method in this embodiment. The flowchart in Figure 3 shows an example of a process performed for one lot containing multiple substrates 8, and can be executed by the control unit 12 according to a program stored in the memory unit. Figure 4 shows the detection of marks in the shot area 8a of the substrate 8 by the alignment scope 10 and / or off-axis scope 11. Figure 4 shows the detection field of view 10a of the alignment scope 10 and / or the detection field of view 11a of the off-axis scope 11. In the following, the shot area 8a of the substrate 8 may be simply referred to as "substrate 8". In the following, the second and subsequent substrates 8 in a lot will be described as "first substrates", and the first substrate 8 will be described as "second substrates", but "second substrates" may be understood as substrates 8 on which focus measurement was performed before the first substrate.

[0036] Steps S101 to S103 are processes performed in common for each of the multiple substrates 8 included in the lot.

[0037] In step S101, the control unit 12 detects the outer marks P3 to P4 located in the center of the substrate 8 in the Y direction using the alignment scope 10. For example, as shown in Figure 4(a), the control unit 12 moves the substrate stage 9 and / or the alignment scope 10 so that the outer marks P3 to P4 of the substrate 8 are positioned within the detection field 10a of the alignment scope 10. Then, the alignment scope 10 is made to detect the outer marks P3 to P4 of the substrate 8.

[0038] In step S102, the control unit 12 uses the off-axis scope 11 to detect the outer marks P1-P2, P5-P6 and inner marks P7-P8 located on the upper and lower parts of the substrate 8 in the Y direction. For example, as shown in Figure 4(a), the control unit 12 moves the substrate stage 9 and / or the off-axis scope 11 so that the marks P1-P2, P5-P8 of the substrate 8 are positioned within the detection field 11a of the off-axis scope 11. Then, the off-axis scope 11 is made to detect the marks P1-P2, P5-P8 of the substrate 8.

[0039] Here, depending on the positional relationship between the alignment scope 10 and the off-axis scope 11, it is possible to simultaneously detect marks P3-P4 with the alignment scope 10 and detect marks P1-P2, P5-P8 with the off-axis scope 11. In this case, steps S101 and S102 may be performed in parallel. Figure 4(a) shows how steps S101 and S102 are performed in parallel.

[0040] In step S103, the control unit 12 uses the alignment scope 10 to detect the outer marks P1-P2 and P5-P6 located on the upper and lower parts of the substrate 8 in the Y direction. For example, as shown in Figure 4(b), the control unit 12 moves the substrate stage 9 so that the outer marks P1-P2 of the substrate 8 are located within the detection field 10a of the alignment scope 10, causing the alignment scope 10 to detect the outer marks P1-P2 of the substrate 8. Similarly, as shown in Figure 4(c), the control unit 12 moves the substrate stage 9 so that the outer marks P5-P6 of the substrate 8 are located within the detection field 10a of the alignment scope 10, causing the alignment scope 10 to detect the outer marks P5-P6 of the substrate 8.

[0041] In steps S102-S103, the same outer marks P1-P2 and P5-P6 are detected by the alignment scope 10 and the off-axis scope 11. In other words, steps S102-S103 perform baseline measurement using each outer mark P1-P2 and P5-P6. This yields the measured baseline value Ba_out when using each outer mark P1-P2 and P5-P6. Note that steps S102-S103 performed on the second and subsequent substrates 8 within a lot may be understood as a measurement process that performs baseline measurement using the first mark of the first substrate.

[0042] In step S104, the control unit 12 determines whether the substrate 8 from which the outer marks P1 to P6 were detected in steps S101 to S103 is the first substrate 8 in the lot. If it is the first substrate 8, the process proceeds to step S105; otherwise, the process proceeds to step S108.

[0043] Steps S105 to S107 are processes performed on the first substrate 8 (second substrate) within the lot.

[0044] In step S105, the control unit 12 detects the inner marks P7 and P8 of the substrate 8 using the alignment scope 10. For example, as shown in Figure 4(d), the control unit 12 moves the substrate stage 9 so that the inner mark P7 of the substrate 8 is positioned within the detection field 10a of the alignment scope 10, causing the alignment scope 10 to detect the inner mark P7 of the substrate 8. Similarly, as shown in Figure 4(e), the control unit 12 moves the substrate stage 9 so that the inner mark P8 of the substrate 8 is positioned within the detection field 10a of the alignment scope 10, causing the alignment scope 10 to detect the inner mark P8 of the substrate 8.

[0045] In steps S102 and S105, the same inner marks P7 to P8 (second marks) are detected by the alignment scope 10 and the off-axis scope 11. In other words, in steps S102 and S105, baseline measurements are performed using each inner mark P7 to P8. As a result, the measured baseline value Ba_in is obtained when using each inner mark P7 to P8.

[0046] In step S106, the control unit 12 obtains the measured baseline values ​​Ba_out when using the outer marks P1~P2 and P5~P6, and the measured baseline values ​​Ba_in when using the inner marks P7~P8, and generates baseline information based on these. As mentioned above, the measured baseline values ​​Ba_out can be obtained in steps S102~S103. The measured baseline values ​​Ba_in can be obtained in steps S102 and S105.

[0047] In step S107, the control unit 12 acquires state information indicating the state of elements that cause the baseline to fluctuate (hereinafter sometimes referred to as fluctuating elements). The baseline may fluctuate due to the influence of physical changes in the master plate 3 (e.g., displacement, rotation, temperature, etc.). Therefore, the control unit 12 acquires state information indicating the state of fluctuating elements that cause the baseline to fluctuate. Here, examples of fluctuating elements include the temperature inside the apparatus where the multiple scopes 10-11 are provided (temperature inside the exposure apparatus EPX), and / or the master plate 3 having a pattern to be transferred onto the substrate 8. Therefore, the control unit 12 may acquire information on the temperature inside the apparatus (e.g., the temperature of the master plate 3) detected by the temperature sensor 17 (see Figure 1) as state information. The temperature sensor 17 may be configured to detect the temperature of the master plate 3. The control unit 12 may also acquire information indicating the orientation (displacement, rotation) of the master plate 3 obtained by detecting marks P1-P8 on the master plate 3 with the alignment scope 10 as state information. The acquired state information is stored in the memory unit and can be used to calculate baseline prediction values, as described later.

[0048] Steps S108 to S116 are processes performed on the second and subsequent substrates 8 (first substrates) within the lot.

[0049] In step S108, the control unit 12 obtains the measured baseline value Ba_out using the outer marks P1~P2 and P5~P6 and stores it in the memory unit. As mentioned above, the measured baseline value Ba_out can be obtained by steps S102~S103. Next, in step S109, the control unit 12 obtains state information indicating the state of the baseline fluctuation elements. Since step S109 is the same process as step S107 mentioned above, a detailed explanation is omitted here.

[0050] In step S110, the control unit 12 calculates a value representing the current state of each component (positional displacement, rotational displacement, magnification, etc.) of each outer mark P1-P2, P5-P6 and each inner mark P7-P8 as the current value Cn. The current value Cn_out for each outer mark P1-P2, P5-P6 can be calculated based on the baseline measured value Ba_out obtained in step S106 for the second substrate 8 and the state information obtained in step S109 for the second substrate 8. Similarly, the current value Cn_in for each inner mark P7-P8 can be calculated based on the baseline measured value Ba_in obtained in step S106 for the first substrate 8 and the state information obtained in step S109 for the second substrate 8. The positional displacement as a component of each mark can be calculated based on the results of baseline measurements performed by the alignment scope 10 and the off-axis scope 11. The amount of rotation can be calculated based on the results of detecting the marks on the original plate 3 using the alignment scope 10. The magnification can be calculated based on the temperature coefficient of change of the original plate 3 and the temperature. When calculating various components, they can be calculated using the difference from when the baseline measured value Ba_in was obtained using the inner marks P7~P8 of the substrate 8. In the following, the various components representing the state of each outer mark obtained from the baseline measurement of the first substrate 8 are defined as the reference value Cbase_out. Also, the various components representing the state of each inner mark obtained from the baseline measurement of the first substrate 8 are defined as the reference value Cbase_in.

[0051] In step S111, the control unit 12 calculates a predicted baseline Bp_out, which is expected to be obtained by baseline measurement using each outer mark P1~P2, P5~P6 (prediction step). The control unit 12 can calculate the predicted baseline Bp_out based on the measured baseline Ba_out obtained using each outer mark of the first substrate 8 and the current state Cn_out of each outer mark obtained in step S110. For example, the control unit 12 multiplies the difference between the current state Cn_out of each outer mark and the reference value Cbase_out by a coefficient Fcoef_out that represents the state change (state change rate) of the baseline fluctuation element.

[0052] The method for calculating the coefficient Fcoef_out will be explained using magnification as an example of the various components of each mark. If "T" is the temperature inside the device (e.g., original plate 3) detected by the temperature sensor 17, "M" is the magnification of original plate 3, and "M(T)" is the function showing the correlation between these, then the coefficient Fcoef_out can be calculated by the following equation (1). In equation (1), "M(0)" represents the magnification of original plate 3 when the reference value Cbase_out is obtained. Coefficients for other various components can be calculated in the same way. JPEG2026090070000002.jpg12170

[0053] The baseline predicted value Bp_out is calculated by multiplying the difference between the current value Cn_out and the reference value Cbase_out by the coefficient Fcoef_out, as shown in equation (2) below, and adding the measured baseline value Ba_out when using the first substrate 8. The baseline predicted value Bp_out may also be calculated for each component of each outer mark. JPEG2026090070000003.jpg12170

[0054] Here, the predicted baseline value Bp_out when using each outer mark may be understood as being calculated based on the measured baseline value Ba_out obtained on the first substrate 8 and state information indicating the state of the baseline fluctuation factors. In this case, the state information may be the state information obtained in step S109 for the second substrate 8. Alternatively, the state information may be information representing the change in the state of the fluctuation elements since the baseline measurement was performed using the first substrate 8. Information representing the change in the state of the fluctuation elements can be obtained, for example, as information showing the difference between the state of the fluctuation elements obtained in step S107 for the first substrate 8 and the state of the fluctuation elements obtained in step S109 for the second substrate 8.

[0055] In step S112, the control unit 12 determines whether the difference between the measured value Ba_out obtained in step S108 and the predicted value Bp_out obtained in step S111 is greater than or equal to a threshold for each outer mark P1~P2, P5~P6. The control unit 12 calculates the difference between the measured value Ba_out and the predicted value Bp_out (|Ba_out-Bp_out|) as shown in equation (3) below, and determines whether this difference is greater than or equal to the threshold Tol. In this embodiment, based on the difference between the measured value Ba_out and the predicted value Bp_out, it is determined whether or not to perform baseline measurement using each inner mark P7~P8 on the second substrate 8 (determination step). JPEG2026090070000004.jpg12170

[0056] If the difference between the measured value Ba_out and the predicted value Bp_out is greater than or equal to the threshold Tol, it can be determined that the baseline is significantly fluctuating due to unpredictable factors originating from the projection optical system 4, excluding the predictable factors among the factors that cause the baseline to fluctuate (fluctuating elements). Using the baseline of the inner mark on the substrate for baseline correction will reduce the overlay accuracy.

[0057] Therefore, if the difference between the measured value Ba_out and the predicted value Bp_out is greater than or equal to the threshold Tol, baseline measurement is performed in steps S113 to S114 using each of the inner marks P7 to P8. Specifically, in step S113, the control unit 12 detects the inner marks P7 to P8 of the substrate 8 using the alignment scope 10. Steps S102 and S113 perform baseline measurement using each of the inner marks P7 to P8, and the measured baseline value Ba_in is obtained when using each of the inner marks P7 to P8. Next, in step S114, the control unit 12 generates baseline information based on the measured baseline value Ba_out when using the outer marks P1 to P2 and P5 to P6, and the measured baseline value Ba_in when using the inner marks P7 to P8. Note that steps S113 to S114 are the same process as steps S105 to S106, so a detailed explanation is omitted here.

[0058] On the other hand, if the difference between the measured value Ba_out and the predicted value Bp_out is less than the threshold Tol, baseline measurement using each inner mark P7~P8 is omitted, and steps S115~S116 are performed.

[0059] In step S115, the control unit 12 calculates the predicted baseline Bp_in, which is expected to be obtained by baseline measurement using each of the inner marks P7 to P8. The control unit 12 can calculate the predicted baseline Bp_in based on the measured baseline Ba_in obtained using each of the inner marks of the first substrate 8 and the current value Cn_in of the state of each inner mark obtained in step S110.

[0060] For example, the control unit 12 multiplies the difference between the current value Cn_in and the reference value Cbase_in of the state of each inner mark by a coefficient Fcoef_in that represents the state change (state change rate) of the baseline variable element. The coefficient Fcoef_in can be calculated by the following equation (4), similar to the coefficient Fcoef_out described in step S111 above. The predicted baseline value Bp_in is calculated by multiplying the difference between the current value Cn_in and the reference value Cbase_in by the coefficient Fcoef_in, as shown in the following equation (5), and adding the measured baseline value Ba_in when the first substrate 8 was used. The predicted baseline value Bp_in may be calculated for each component of each outer mark. Step S115 may be performed in step S111. JPEG2026090070000005.jpg12170JPEG2026090070000006.jpg12170

[0061] In step S116, the control unit 12 generates baseline information based on the measured baseline value Ba_out when using the outer marks P1~P2 and P5~P6, and the predicted baseline value Bp_in when using the inner marks P7~P8. In this way, if the difference between the measured value Ba_out and the predicted value Bp_out is less than the threshold Tol, baseline information is generated based on the predicted baseline value Bp_in when using the inner marks P7~P8.

[0062] As described above, when generating baseline information using the outer and inner marks of the substrate 8, the decision of whether or not to perform baseline measurement using the inner marks is made based on the difference between the measured and predicted baseline values ​​when using the outer marks. This allows for variable decimation (omission) of baseline measurements using the inner marks, which can be advantageous in terms of productivity.

[0063] In this embodiment, an example was described in which the decision of whether or not to perform baseline measurement using inner marks is made based on the difference between the measured baseline value Ba_out and the predicted baseline value Bp_out when using outer marks. However, the indicator used to decide whether or not to perform baseline measurement using inner marks is not limited to the difference between the measured value Ba_out and the predicted value Bp_out, but may also be, for example, the ratio of the measured value Ba_out to the predicted value Bp_out.

[0064] Furthermore, in this embodiment, as shown in Figure 2, an example was described in which two inner marks are provided on both the original plate 3 and the substrate 8. However, the number of inner marks is not limited to two; it may be one or three or more. In addition, in this embodiment, an example was described in which baseline measurement is determined for the inner marks, but the decision may also be made for the outer marks. For example, depending on whether the difference between the measured baseline value and the predicted baseline value when using some of the outer marks is greater than or equal to a threshold, the decision may be made whether or not to perform baseline measurement on the other outer marks, and whether or not to perform baseline measurement on the inner marks. In this case, baseline measurement may be omitted for both the other outer marks and the inner marks.

[0065] <Embodiment of Article Manufacturing Method> The article manufacturing method according to an embodiment of the present invention is suitable for manufacturing articles such as microdevices such as semiconductor devices and elements having a microstructure. The article manufacturing method of this embodiment includes an exposure step of exposing a substrate using the above-described exposure apparatus (exposure method), a processing step of processing the substrate exposed in the exposure step, and a manufacturing step of manufacturing an article from the substrate processed in the processing step. The exposure step may include a step of forming a latent image pattern on a photosensitive agent coated on the substrate by exposing the substrate using the above-described exposure apparatus. The processing step may also include a step of developing the substrate on which the latent image pattern has been formed. Furthermore, the article 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 this embodiment is advantageous over conventional methods in at least one of the performance, quality, productivity, and production cost of the article.

[0066] <Other examples> The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0067] <Summary of Embodiments> The disclosures herein include at least the following generation methods, exposure methods, exposure apparatuses, article manufacturing methods, and programs. (Item 1) A generation method for generating spacing information indicating the distance between optical axes in multiple scopes that detect marks on a substrate using different methods, using the first and second marks on the substrate, respectively. A measurement step in which a measurement process is performed using the first mark on the first substrate to detect marks using the plurality of scopes and measure the interval, A prediction step that predicts the interval obtained in the measurement process using the first mark on the first substrate, based on the result of measuring the interval using the first mark on a second substrate different from the first substrate, and state information indicating the state of the elements that cause the interval to vary, A decision step, which determines whether or not to perform the measurement process using the second mark on the first substrate, based on the interval measured in the measurement step and the interval predicted in the prediction step, A method for generating a product, characterized by including the following: (Item 2) The generation method according to item 1, characterized in that in the determination step, it is determined whether or not to perform the measurement process using the second mark on the first substrate based on the difference between the interval measured in the measurement step and the interval predicted in the prediction step. (Item 3) The generation method according to item 2, characterized in that, in the determination step, if the difference is greater than or equal to a threshold, the measurement process is performed using the second mark on the first substrate, and if the difference is less than a threshold, the measurement process using the second mark on the first substrate is omitted. (Item 4) In the aforementioned decision process, If the difference is greater than or equal to a threshold, the measurement process is performed using the second mark on the first substrate to generate the interval information using the second mark. The generation method according to item 2 or 3, characterized in that, if the difference is less than the threshold, the interval information is generated by predicting the interval obtained in the measurement process using the second mark of the first substrate based on the result of measuring the interval using the second mark of the second substrate and the state information. (Item 5) The generation method according to any one of items 1 to 4, characterized in that the measurement step generates the interval information by performing the measurement process using the first mark on the first substrate. (Item 6) The generation method according to any one of items 1 to 5, characterized in that the element whose state is indicated by the state information includes the temperature inside the apparatus provided with the plurality of scopes. (Item 7) The generation method according to any one of items 1 to 6, characterized in that the element whose state is indicated by the state information includes a master plate having a pattern to be transferred onto the first substrate. (Item 8) The generation method according to any one of items 1 to 7, characterized in that the state information includes information indicating the change in the state of the element after measuring the gap using the second substrate. (Item 9) The generation method according to any one of items 1 to 8, characterized in that the plurality of scopes are provided in an exposure apparatus that exposes a substrate via a projection optical system, and include a first scope that detects marks on the substrate via the projection optical system, and a second scope that detects marks on the substrate without going through the projection optical system. (Item 10) A generation step in which spacing information indicating the spacing between optical axes in multiple scopes that detect marks on a substrate in different ways is generated using the generation method described in any one of items 1 to 9, using the first mark and second mark on the substrate, respectively. Based on the spacing information generated in the generation process, a positioning distance is used to position the substrate, An exposure step in which the substrate positioned in the positioning step is exposed, An exposure method characterized by including the following. (Item 11) A program that causes a computer to execute one of the generation methods described in item 1 through 9. (Item 12) An exposure apparatus for exposing a substrate, Multiple scopes that detect marks on a circuit board using different methods, The system includes a control unit that generates spacing information indicating the distance between optical axes in the plurality of scopes using a first mark and a second mark on the substrate, and controls the positioning of the substrate based on the spacing information, The aforementioned generation process is A measurement step in which a measurement process is performed using the first mark on the first substrate to detect marks using the plurality of scopes and measure the interval, A prediction step that predicts the interval obtained in the measurement process using the first mark on the first substrate, based on the result of measuring the interval using the first mark on a second substrate different from the first substrate, and state information indicating the state of the elements that cause the interval to vary, An exposure apparatus characterized by including a determination step of determining whether or not to perform the measurement process using the second mark on the first substrate, based on the interval measured in the measurement step and the interval predicted in the prediction step. (Item 13) An exposure process in which a substrate is exposed using the exposure apparatus described in item 12, A processing step for processing the substrate exposed in the exposure step, A manufacturing process for producing an article from the substrate processed in the above-mentioned processing step, A method for manufacturing articles, characterized by including the following:

[0068] The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, claims are attached to disclose the scope of the invention. [Explanation of Symbols]

[0069] 1: Illumination optics, 2: Master stage, 3: Master plate, 4: Projection optics, 8: Substrate, 9: Substrate stage, 10: Alignment scope, 11: Off-axis scope, 12: Control unit, EXP: Exposure apparatus

Claims

1. A generation method for generating spacing information indicating the distance between optical axes in multiple scopes that detect marks on a substrate using different methods, using a first mark and a second mark on the substrate, respectively. A measurement step in which a measurement process is performed using the first mark on the first substrate to detect marks using the plurality of scopes and measure the interval, A prediction step in which the interval obtained in the measurement process using the first mark on the first substrate is predicted based on the result of measuring the interval using the first mark on a second substrate which is different from the first substrate, and state information indicating the state of the elements that cause the interval to vary, A decision step, which determines whether or not to perform the measurement process using the second mark on the first substrate, based on the interval measured in the measurement step and the interval predicted in the prediction step, A method for generating a product, characterized by including the following:

2. The generation method according to claim 1, characterized in that the determination step determines whether or not to perform the measurement process using the second mark on the first substrate, based on the difference between the interval measured in the measurement step and the interval predicted in the prediction step.

3. The generation method according to claim 2, characterized in that, in the determination step, if the difference is greater than or equal to a threshold, the measurement process is performed using the second mark on the first substrate, and if the difference is less than a threshold, the measurement process using the second mark on the first substrate is omitted.

4. In the aforementioned decision process, If the difference is greater than or equal to a threshold, the measurement process is performed using the second mark on the first substrate to generate the interval information using the second mark. The generation method according to claim 2, characterized in that, if the difference is less than the threshold, the interval information is generated by predicting the interval obtained in the measurement process using the second mark of the first substrate based on the result of measuring the interval using the second mark of the second substrate and the state information.

5. The generation method according to claim 1, characterized in that the measurement step generates the interval information by performing the measurement process using the first mark on the first substrate.

6. The generation method according to claim 1, characterized in that the element whose state is indicated by the state information includes the temperature inside the apparatus provided with the plurality of scopes.

7. The generation method according to claim 1, characterized in that the element whose state is indicated by the state information includes a master plate having a pattern to be transferred onto the first substrate.

8. The generation method according to claim 1, characterized in that the state information includes information indicating the change in the state of the element after measuring the gap using the second substrate.

9. The generation method according to claim 1, characterized in that the plurality of scopes are provided in an exposure apparatus that exposes a substrate via a projection optical system, and include a first scope that detects marks on the substrate via the projection optical system, and a second scope that detects marks on the substrate without going through the projection optical system.

10. A generation step of generating spacing information indicating the spacing between optical axes in a plurality of scopes that detect marks on a substrate in different ways, using the generation method described in any one of claims 1 to 9, using the first mark and the second mark on the substrate, respectively; Based on the spacing information generated in the generation process, a positioning distance is used to position the substrate, An exposure step in which the substrate positioned in the positioning step is exposed, An exposure method characterized by including

11. A program for causing a computer to execute the generation method described in any one of claims 1 to 9.

12. An exposure apparatus for exposing a substrate, Multiple scopes that detect marks on a circuit board using different methods, The system includes a control unit that generates spacing information indicating the distance between optical axes in the plurality of scopes using a first mark and a second mark on the substrate, and controls the positioning of the substrate based on the spacing information, The aforementioned generation process is A measurement step in which a measurement process is performed using the first mark on the first substrate to detect marks using the plurality of scopes and measure the interval, A prediction step in which the interval obtained in the measurement process using the first mark on the first substrate is predicted based on the result of measuring the interval using the first mark on a second substrate which is different from the first substrate, and state information indicating the state of the elements that cause the interval to vary, An exposure apparatus characterized by including a determination step of determining whether or not to perform the measurement process using the second mark on the first substrate, based on the interval measured in the measurement step and the interval predicted in the prediction step.

13. An exposure step of exposing a substrate using the exposure apparatus described in claim 12, A processing step for processing the substrate exposed in the exposure step, A manufacturing process for producing an article from the substrate processed in the above-mentioned processing step, A method for manufacturing articles, characterized by including the following:

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