Information processing method, information processing device, lithography device, program, and method for manufacturing articles
The method improves alignment accuracy by equally dividing the substrate's outer perimeter to select shot regions, addressing uneven distribution and local variations, thereby reducing correction residuals.
Patent Information
- Application Number
- JP2022115054
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2021-11-10
- Filing Date
- 2022-07-19
- Publication Date
- 2026-05-14
- Estimated Expiration
- 2042-07-19
AI Technical Summary
Existing methods for selecting sample shot regions on substrates assume a circular shape and aspect ratio of 1:1, leading to uneven distribution and potential alignment accuracy issues due to local substrate variations.
An information processing method that selects shot regions by equally dividing the outer perimeter of the target area based on length, ensuring even distribution and improved alignment accuracy.
Enhances alignment accuracy by reducing correction residuals, particularly in substrates with non-1:1 aspect ratios, by evenly distributing sample shot regions.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to an information processing method, an information processing apparatus, a lithography apparatus, a program, and an article manufacturing method.
Background Art
[0002] For example, in a semiconductor exposure apparatus, when performing overlay exposure on each shot area of a substrate, alignment between the pattern of a reticle and the chip pattern within each shot area is performed. Conventionally, global alignment has been used in view of the balance between productivity and measurement accuracy. Global alignment is a technique for obtaining the arrangement positions of all other shot areas by statistical processing using measurement values of a predetermined number of shot areas (sample shot areas) in a substrate, and performing alignment of all shot areas based thereon. An exposure apparatus generally has a function of selecting a predetermined number of sample shot areas suitable for alignment and focus leveling.
[0003] Patent Document 1 describes selecting one sample shot area from each region obtained by dividing a substrate by a straight line passing through the center of the substrate so that the central angles are equal to each other.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] However, the selection method described in Patent Document 1 assumes that the substrate is circular and divides the region based on the central angle. Therefore, even if the substrate is circular, if the aspect ratio of the selected area of the sample shot region is not 1:1 as shown in Figure 5, the multiple sample shot regions to be selected may not be evenly distributed within that area, resulting in a bias. If a bias occurs, the alignment accuracy may decrease due to the influence of local changes in the substrate.
[0006] The present invention provides, for example, a technology that is advantageous for improving alignment accuracy. [Means for solving the problem]
[0007] According to one aspect of the present invention, an information processing method is provided, characterized by comprising: an acquisition step of acquiring a target area including a plurality of shot regions; and a selection step of selecting, from among the plurality of shot regions, shot regions corresponding to division positions in which the outer periphery of the target area is equally divided into a predetermined number of parts based on length, as sample shot regions to be used for substrate alignment. [Effects of the Invention]
[0008] According to the present invention, it is possible to provide a technology that is advantageous for improving alignment accuracy. [Brief explanation of the drawing]
[0009] [Figure 1] A diagram showing the configuration of an exposure apparatus. [Figure 2] A diagram showing an example of a shot layout. [Figure 3] Flowchart of the exposure sequence. [Figure 4] A diagram showing an example of the layout of shot areas on a rectangular substrate. [Figure 5] A diagram showing an example of the layout of shot areas on a circular substrate. [Figure 6] A diagram showing the functional configuration for implementing the sample shot selection process. [Figure 7]Flowchart of sample shot selection process. [Figure 8] Flowchart of automatic sample shot selection process. [Figure 9] Diagram explaining the automatic sample shot selection process. [Figure 10a] Diagram showing an example of the selection result of the sample shot area for a rectangular substrate. [Figure 10b] Diagram showing an example of the selection result of the sample shot area for a circular substrate. [Figure 10c] Diagram showing the effect of the embodiment on the prior art. [Figure 11] Diagram showing an example of the sample shot selection target area from which the peripheral shot area is excluded. [Figure 12] Diagram showing an example of the sample shot area selected within the sample shot selection target area from which the peripheral shot area is excluded. [Figure 13a] Diagram showing an example where the first sample shot area is set at the upper right corner. [Figure 13b] Diagram showing an example where sample shot areas are set at the four corners of a square substrate. [Figure 14] Diagram showing an example of the result where other sample shot areas are selected after the first sample shot area is set at the upper right corner. [Figure 15a] Diagram explaining the grouping of shot areas in the sample shot selection target area. [Figure 15b] Diagram exemplifying the group selected as candidates for the sample shot area. [Figure 15c] Diagram showing an example of the result of selecting the sample shot area from the group in Fig. 15b. [Figure 16a] Diagram explaining the grouping of shot areas in the sample shot selection target area from which the peripheral shot area is excluded. [Figure 16b] Diagram exemplifying the group selected as candidates for the sample shot area. [Figure 16c] Diagram showing an example of the result of selecting the sample shot area from the group in Fig. 16b. [Figure 17a] A diagram showing particles existing above the sample shot area. [Figure 17b] A diagram explaining changing the sample shot area to an adjacent shot area without particles.
Embodiments for Carrying Out the Invention
[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiments, not all of these plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Further, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and duplicate descriptions are omitted.
[0011] <First Embodiment> The present invention relates to an information processing method, an information processing apparatus, a lithography apparatus, a program, and an article manufacturing method. In the following first embodiment, an exposure apparatus which is a specific example of a lithography apparatus will be described. In the first embodiment, the exposure apparatus will be described as including a CPU 9 that functions as a control unit for controlling the operation of the entire exposure apparatus. However, such an information processing apparatus including the CPU 9 may be an external apparatus of the exposure apparatus. In other words, although the upper processing apparatus is embodied as an exposure apparatus in the present embodiment, the information processing apparatus is not limited to the exposure apparatus. Further, the information processing method of the present invention can be realized by the information processing apparatus. FIG. 1 is a diagram showing the configuration of the exposure apparatus in the embodiment. In this specification and the drawings, directions are indicated in the XYZ coordinate system with the horizontal plane being the XY plane. Generally, the substrate W1 is placed on the substrate stage 11 such that its surface is parallel to the horizontal plane (XY plane). Therefore, hereinafter, the directions orthogonal to each other within the plane along the surface of the substrate W1 are taken as the X-axis and the Y-axis, and the direction perpendicular to the X-axis and the Y-axis is taken as the Z-axis. Further, hereinafter, the directions parallel to the X-axis, the Y-axis, and the Z-axis in the XYZ coordinate system are referred to as the X direction, the Y direction, and the Z direction, respectively.
[0012] In Figure 1, an exposure beam from an exposure illumination system (not shown) is irradiated onto a circuit pattern formed on a reticle R. The pattern irradiated by the exposure beam is projected onto a substrate W1 via a projection optical system 1 and exposed. As the illumination light for exposure, g-line and i-line light from a mercury lamp, or ultraviolet pulsed light from an excimer laser light source may be used. The substrate W1 is held by a chuck CK provided on a substrate stage 11 that is movable in the X and Y directions. An alignment optical system SHO detects the position of the substrate W1 in the X direction. A similar alignment optical system (not shown) is also installed to detect the position of the substrate W1 in the Y direction. The CPU 9 functions as a control unit that controls the operation of the entire exposure apparatus. In this embodiment, the CPU 9 also functions as a processing unit of an information processing device that performs the process of selecting multiple sample shot areas from among multiple shot areas arranged on the substrate. The storage device 12 can store various data, including a control program executed by the CPU 9. The storage device 12 may include a memory or a storage medium such as a hard disk drive. An optical autofocus device (AF) may include a light-emitting unit (LD) and a light-receiving unit (PD) for measuring the position on the substrate surface.
[0013] The alignment optical system SHO comprises a light source 2 that generates light in a frequency band that does not expose the resist (photosensitive material) coated on the substrate W1, a beam splitter 3, an imaging optical system 4, and an imaging device 5 that photoelectrically converts the image formed by the imaging optical system 4. The A / D converter 6 converts the output of the imaging device 5 into a two-dimensional digital signal. The integrator 7 applies a processing window to this digitized two-dimensional image signal and performs moving average processing in the Y direction within the window to obtain a one-dimensional digital signal sequence S(x). The position detection device 8 performs pattern matching on the one-dimensional digital signal sequence S(x) output from the integrator 7 using a pre-stored template pattern and outputs the address position of S(x) to the CPU 9 based on the degree of agreement with the template pattern. The stage drive device 10 drives the substrate stage 11 based on drive command values from the control unit CPU 9.
[0014] Figure 2 shows an example of the layout of multiple shot regions on a substrate W1. The substrate W1 illustrated in Figure 2 has eight pre-selected sample shot regions SS1 to SS8. Alignment marks M1 to M8 are placed in each of the sample shot regions SS1 to SS8. Alignment marks are, for example, multiple rectangular patterns of the same shape placed at a constant pitch. In the following text, "shot region" may simply be referred to as "shot".
[0015] Next, with reference to Figure 3, the exposure sequence by the exposure apparatus in this embodiment will be described. In this embodiment, multiple sample shot regions are selected according to the method described later. When the exposure sequence is started, prior to exposure, measurements for relative alignment and focus leveling between the reticle R and the substrate W1 are performed in S81 to S87.
[0016] First, in S81, the substrate W1 is brought into the apparatus by a substrate transport device (not shown) and placed on the chuck CK on the substrate stage 11. The chuck CK then grips the placed substrate W1.
[0017] In S82, the CPU 9 controls the substrate stage 11 via the stage drive unit 10 so that the sample shot area of interest is positioned at the measurement position of the optical autofocus device AF. Next, in S83, the CPU 9 controls the optical autofocus device AF to perform focus measurement on the sample shot area. In S84, the CPU 9 determines whether focus measurement has been completed for all sample shot areas. If focus measurement has not been completed for all sample shot areas, the process returns to S82, and focus measurement is performed on the next sample shot area. In this way, focus measurement is performed for all sample shot areas SS1 to SS8 in S82 to S84.
[0018] Once focus measurement is complete in all sample shot areas, the process proceeds to S85. In S85, the CPU 9 sends a command to the stage drive unit 10 to drive the substrate stage 11 so that the alignment mark of the sample shot area of interest (here, for example, sample shot area SS1) is located within the field of view of the alignment optical system SHO. In S86, the CPU 9 performs alignment measurement on the sample shot area SS1. Specifically, the CPU 9 controls the alignment optical system SHO to illuminate the alignment mark M1 of the sample shot area SS1. The light beam reflected from the alignment mark M1 reaches the beam splitter 3 again via the projection optical system 1 and reticle R, where it is reflected and forms an image of the alignment mark M1 on the imaging surface of the imaging device 5 via the imaging optical system 4. This image is photoelectrically converted in the imaging device 5, converted into a two-dimensional digital signal in the A / D converter 6, and further converted into a one-dimensional digital signal sequence S(x) by the integrator 7. The position detection device 8 performs pattern matching on this digital signal sequence S(x), and detects the address position of S(x) with the highest degree of agreement with the template pattern. This output signal is the position of the alignment mark M1 relative to the imaging surface of the imaging device 5. The CPU 9, acting as the measurement unit, calculates the position of the alignment mark M1 relative to the reticle R from the relative positions of the imaging device 5 and the reticle R, which have been determined in advance by a method not shown. This gives the X-direction positional displacement of the first measurement shot S1 as the measurement result. Next, the CPU 9 measures the Y-direction positional displacement using the same procedure as the X-direction measurement. This completes the alignment measurement for the sample shot region SS1.
[0019] Furthermore, alignment measurements are performed for alignment marks M2 to M8 in the other sample shot areas using the same procedure. If it is determined in S87 that alignment measurements have been performed for all alignment marks, the process proceeds to S88.
[0020] In S88, the CPU9 performs focus leveling based on the results of measurements for focus leveling. In S89, the CPU9 performs alignment correction based on the results of alignment measurements. For example, global alignment is used for alignment correction. Specifically, the CPU9 performs statistical calculations using the measured values of the alignment marks of the sample shot area obtained in S85 to S87 to determine the arrangement positions of all other shot areas, and aligns all shot areas based on that. In S90, the CPU9 performs step-and-repeat exposure. In this way, the exposure apparatus of this embodiment forms a pattern on the substrate while controlling the substrate stage 11 so that the position of the substrate is corrected based on the measurement results. In S91, when it is determined that the exposure of all shot areas has been completed, in S92 the substrate W1 is unloaded by a substrate transport device (not shown).
[0021] The sequence from S81 to S92 described above is repeated until there are no more unprocessed substrates. In S93, when it is determined that exposure has been completed for all substrates, the exposure sequence ends.
[0022] Figure 4 shows an example of a shot area layout when the outer perimeter of the substrate W1 is rectangular. Figure 5 shows an example of a shot area layout when the outer perimeter of the substrate W1 is circular. The size of a single shot area may depend on the exposure screen size of the exposure apparatus. For these layouts, the sample shot area for global alignment and global leveling can be manually selected by the user, or it can be automatically selected using a selection algorithm. In this embodiment, measurement errors that may occur due to variations in resist film thickness in the peripheral shot area of the substrate or distortion of the substrate W1 itself are not taken into consideration. Therefore, in this embodiment, the peripheral shot area of the substrate may also be preferentially selected as a sample shot.
[0023] Figure 6 is a diagram showing the functional configuration of an information processing device for realizing sample shot selection processing in an exposure apparatus according to this embodiment. Figure 7 is a flowchart of the sample shot area selection process. This sample shot area selection process is executed prior to the exposure sequence shown in Figure 3. In Figure 6, an input / output device 31 and a storage device 12 are shown as hardware elements. The input / output device 31 may include, for example, a keyboard as an input device and a display unit as an output device. Each functional unit in Figure 6 may be realized by a CPU 9. The CPU 9 may also function as a display control unit that controls the display of the display unit based on an image signal.
[0024] In S41, the process information input unit 32 inputs process information corresponding to the operator's operation of the input / output device 31. The input process information is stored in the storage device 12.
[0025] The selection method input unit 34 is used to input the sample shot selection method. Here, the operator can specify whether to automatically select or manually select the sample shot area by operating the input / output device 31. In S42, the CPU 9 determines whether to automatically select or manually select the sample shot area according to the operator's specification via the input / output device 31.
[0026] If automatic selection is specified, in S43, the selection algorithm determination unit 35 determines a selection algorithm based on the process information 33 input in S41 and stored in the storage device 12. For example, the storage device 12 stores multiple selection algorithms. The storage device 12 also stores a table showing the relationship between which selection algorithm is most effective for the process information 33. The selection algorithm determination unit 35 selects a selection algorithm corresponding to the process information 33 by referring to this table. In S44, the sample shot automatic selection unit 36 executes an automatic selection process of sample shot areas according to the selection algorithm determined in S43. Once the automatic selection process of sample shot areas is completed, the process proceeds to S45.
[0027] On the other hand, if manual selection is specified in S42, the process proceeds to S46. In S46, the sample shot manual selection unit 39 accepts the operator's free selection of the sample shot area via the input / output device 31. After the manual selection is completed, the process proceeds to S45.
[0028] In S45, the sample shot setting unit 37 sets the shot area selected in S44 or S46 as the sample shot area.
[0029] In the explanations of Figures 6 and 7 above, we have described how to determine the sample shot area for alignment. However, the sample shot area for focus leveling can be determined in the same manner as described above, so its explanation is omitted here. Furthermore, if there are processes other than alignment and focus leveling that require a sample shot area, the sample shot areas for those processes may also be determined in the same manner as described above.
[0030] In S45, once all sample shot areas for alignment and focus leveling are set, the process proceeds to S47. The functional configuration in Figure 6 may include a transmission unit 38 that transmits an image signal based on the processing information obtained by the processing unit (CPU 9). In S47, the transmission unit 38 transmits an image signal containing information about the relative positional relationship between the selected target area and the selected sample shot area to the display control unit. Subsequently, based on the operator's instructions, the exposure sequence is started in S48.
[0031] Figure 8 shows a flowchart of the automatic sample shot selection process in S44. In S51, the CPU 9 (automatic sample shot selection unit) stores the shape of the shot layout on the substrate W1 in the storage device 12. In S52, the CPU 9 obtains multiple sample shot area selection targets (sample shot selection target areas) from the layout shape stored in S51 and stores the information. Figure 9 shows an example of a sample shot selection target area. The sample shot selection target area exemplified in Figure 9 has an outer perimeter shape in which the length of the center line (X-axis) extending in the X direction (first direction) and the length of the center line (Y-axis) extending in the Y direction (second direction) perpendicular to the first direction are different (i.e., the aspect ratio is not 1:1). Such an outer perimeter shape can typically be a rectangle (rectangle) having a long side extending parallel to the X direction and a short side extending parallel to the Y direction, as shown in Figure 9. A sample shot target area having such a rectangular outer perimeter shape can be particularly suitable for a rectangular substrate. However, such outer perimeter shapes can also be as shown in Figure 10b, which is set for a circular substrate. The outer perimeter shape of the sample shot selection area shown in Figure 10b also does not have a 1:1 aspect ratio.
[0032] In S53, CPU9 determines the length of the outer perimeter of the sample shot selection target area. In S54, CPU9 divides the outer perimeter of the sample shot selection target area into a predetermined number of equal parts (a predetermined number of sample shot regions). By dividing the length of the outer perimeter determined in S53 by the predetermined number, the length of the equally divided outer perimeter segments can be determined. The predetermined number is the number of sample shot regions included in the process information input in S41, and in the example of Figure 9, it is 8. CPU9 can obtain the value obtained by dividing the length of the outer perimeter determined in S53 by the predetermined number as the interval between the predetermined number of division points (division positions). Figure 9 shows the predetermined number of division points D1 to D8 (boundaries of the equally divided outer perimeter segments) obtained in this way. In the example of Figure 9, the outer perimeter is divided into a predetermined number of parts starting from the intersection point (division point D1) between the center line (X-axis) extending in the X direction (first direction) of the sample shot selection target area and the outer perimeter of the sample shot selection target area.
[0033] In S55, the CPU 9 selects a predetermined number of shot regions corresponding to a predetermined number of division points D1 to D8 as multiple sample shot regions. For example, the CPU 9 first determines the shot region corresponding to the starting point of the division points (division point D1 located on the outer periphery at 0° on the X axis) as the first sample shot region SS1. Then, it determines the shot regions corresponding to the other division points D2 to D8 as sample shot regions. Here, the shot region "corresponding" to a division point can be understood as the shot region to which the division point belongs. Therefore, the CPU 9 can determine the shot regions to which each of the division points D1 to D8 belongs as sample shot regions. In this way, multiple sample shot regions SS1 to SS8 are determined as shown in Figure 10a. Sample shot regions SS1 to SS8 can be determined similarly for a circular substrate as shown in Figure 10b. The shot regions corresponding to a predetermined number of division positions may, for example, be the shot regions between the shot region to which the division position belongs and the two adjacent shot regions. In this case, preferably, the shot regions corresponding to a predetermined number of division positions may be the shot regions adjacent to the shot region to which the division position belongs. More preferably, the shot regions corresponding to a predetermined number of division positions may be the shot region to which the division position belongs. In one example, when shifting a sample shot region within the range of the two adjacent shot regions from the shot region to which the division position belongs, it is shifted towards the side closer to the division position. Also, when shifting a sample shot region, if it is necessary to shift neighboring sample shot regions as well, in order to prevent the spacing between sample shot regions from deviating significantly from equal intervals, the shift is made in accordance with the direction of the shift of the neighboring sample shot regions. Alternatively, a shot region corresponding to a predetermined number of division positions may be the shot region where the division position and the alignment mark are closest.
[0034] Figure 10c shows the effect of this embodiment compared to the prior art. The conventional algorithm is a method of selecting a sample shot area by dividing the region based on the central angle of the substrate, as shown in, for example, Japanese Patent Application Publication No. 2001-118769. Figure 10c shows the results of the correction residual after selecting the sample shot area and performing global alignment using the methods of the prior art and this embodiment. In Figure 10c, the vertical axis shows the correction residual [nm], and the horizontal axis shows the x and y directions of the substrate and each algorithm. According to the comparison results in Figure 10c, it was confirmed that this embodiment can reduce the correction residual by 7.2 [nm] in the x direction and 7.2 [nm] in the y direction.
[0035] <Second Embodiment> In the second embodiment, a case will be described in which measurement errors occur due to reasons such as large distortion of the substrate W1 caused by the process. In this case, if the peripheral shot area of the substrate is preferentially selected as the sample shot, the distortion of the substrate will have an effect when performing global alignment. Therefore, as shown in Figure 11, the sample shot selection target area is set to the area excluding the peripheral shot area of the rectangular substrate.
[0036] If the sample shot area is selected from the inside of the substrate, the accuracy of the measured values regarding the magnification and rotation of the shot array may decrease; therefore, the sample shot area is selected from outside the selection area. Figure 12 shows an example of a sample shot area selected within the selection area, excluding the peripheral shot area of the substrate. After the selection area is limited to the area excluding the peripheral shot area of the rectangular substrate, the sample shot area is set in the same manner as in the first embodiment.
[0037] <Third Embodiment> In the first embodiment, as shown in the example in Figure 9, the outer perimeter was divided into a predetermined number of parts, with the intersection of the center line (X-axis) extending in the X direction of the sample shot selection area and the outer perimeter of the sample shot selection area as the starting point (division point D1). However, in the present invention, the starting point may be set at another position. For example, as shown in Figure 13a, the outer perimeter may be divided into a predetermined number of parts, starting from one of the four corners of the rectangle that is furthest from the center of the substrate (for example, the upper right corner).
[0038] If the substrate is square, as shown in Figure 13b, the shot area in the upper right corner is selected as the first sample shot area. Furthermore, the shot areas in the three corners, shifted by 45 degrees at their central angles, are selected as the second, third, and fourth sample shot areas, respectively. By doing this, the four sample shot areas are positioned evenly and far apart from each other, which is why selecting the upper right corner shot area as the first sample shot area is meaningful.
[0039] Figure 14 shows the result after the shot area in the upper right corner of the substrate was selected as the first sample shot area, as described above, and then the remaining sample shot areas were further selected using the method shown in the first embodiment. As a modification, after the shot areas in the four corners of the substrate were selected as sample shot areas, additional sample shot areas may be further selected using the method shown in the first embodiment.
[0040] <Fourth Embodiment> In the sample shot selection area, within the area most likely to be selected as a sample shot region, multiple groups are created, each consisting of a predetermined number of adjacent shot regions. Figure 15a shows an example where multiple groups G1 to G16 are created. The number of shot regions constituting one group may be, for example, four or nine, but is not limited to these. In the example in Figure 15a, groups consisting of four shot regions and groups consisting of nine shot regions are mixed together. The number of shot regions included in one group may be determined according to process conditions such as the shot layout.
[0041] Each created group is considered as a single shot region, and the sample shot region is selected in the manner described in the first embodiment. Specifically, first, the CPU 9 selects a subset of groups from the multiple groups that correspond to each division point obtained by the equal division of the outer perimeter. Here, the group "corresponding" to a division point may be understood as the group to which the division point belongs. Therefore, the CPU 9 can select the group to which each of the division points D1 to D8 belongs. Figure 15b shows an example of the result. According to the example in Figure 15b, groups G1, G3, G5, G7, G9, G11, G13, and G15 in Figure 15a were selected as subsets of groups corresponding to each division point. Subsequently, the CPU 9 selects one shot region from each of the selected subsets as a sample shot region. There are no limitations on the method of selecting the sample shot region in each group. For example, the shot region furthest from the center of the substrate in each group may be selected as the sample shot region, but each group may have its own exclusion criteria depending on the process conditions, etc. Figure 15c shows examples of sample shot regions selected from each group.
[0042] Figure 16a shows an example of creating groups by excluding the surrounding shot area from the sample shot selection area. In Figure 16a, multiple groups G1 to G12 were created. From these multiple groups, the CPU 9 selects a subset of groups corresponding to each division point obtained by the equal division of the outer perimeter. Here, the group "corresponding" to a division point can be understood as the group to which the division point belongs. Therefore, the CPU 9 can select the group to which each division point D1 to D8 belongs. Figure 16b shows an example of the result. According to the example in Figure 16b, groups G1, G2, G4, G5, G7, G8, G10, and G11 from Figure 16a were selected as subsets of groups corresponding to each division point. Subsequently, the CPU 9 selects one shot area from each of the selected subsets as the sample shot area. There are no limitations on how the sample shot area is selected in each group. For example, the shot area furthest from the center of the substrate may be selected as the sample shot area in each group, but each group may have its own exclusion criteria depending on the process conditions, etc. Figure 16c shows examples of sample shot regions selected from each group.
[0043] As described above, according to the fourth embodiment, the shot regions in the sample shot selection target area are grouped, and multiple groups are created. Then, some of the groups are selected in the same manner as in the first embodiment, and a sample shot region is selected from each of these groups. According to this embodiment, the sample shot region can be selected according to the criteria of each group.
[0044] <Fifth Embodiment> The fifth embodiment further includes a step of changing the sample shot region to another shot region where no abnormality is detected if an abnormality is detected in the selected sample shot region. Specific examples are described below.
[0045] First, the sample shot area is selected using the method described in the first embodiment. Subsequently, foreign matter (particles) may be detected on the sample shot area SS3 during the foreign matter inspection on the substrate, as shown in Figure 17a. In this case, the sample shot area may be changed to a shot area adjacent to SS3, as shown in Figure 17b. In the example of Figure 17b, a shot area adjacent to the sample shot area SS3 shown in Figure 17a in a counterclockwise direction from the center of the substrate is selected as the new sample shot area. If particles are detected in the changed sample shot area, another shot area adjacent in a counterclockwise direction may be selected as the new sample shot area. Note that selecting adjacent shot areas in a counterclockwise direction is just one example; adjacent shot areas in the opposite direction may also be selected.
[0046] Furthermore, even when particles are detected, factors such as substrate distortion or scratches on the alignment marks may cause the correlation between the measured alignment marks and the alignment marks registered as templates to be smaller than the threshold. In such cases, the sample shot area may be changed to an adjacent shot area.
[0047] <Embodiment of Article Manufacturing Method> The article manufacturing method in this embodiment is suitable for manufacturing articles such as microdevices, semiconductor devices, and elements having microstructures. The article manufacturing method of this embodiment includes the steps of transferring a pattern from a master plate onto a substrate using the above-mentioned lithography apparatus (such as an exposure apparatus, imprint apparatus, or drawing apparatus), and processing the substrate onto which the pattern has been transferred. Furthermore, this manufacturing method includes other well-known steps (such as oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, and packaging). 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.
[0048] (Other embodiments) 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 a process in which 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.
[0049] 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]
[0050] 12: Storage device, 31: Input / output device, 32: Process information input unit, 34: Selection method input unit, 35: Selection algorithm determination unit, 36: Automatic sample shot selection unit, 37: Sample shot setting unit
Claims
1. The acquisition process involves acquiring a target area that includes multiple shot regions, A selection step of selecting, from among the plurality of shot regions, a shot region corresponding to a division position in which the outer periphery of the target area is divided equally into a predetermined number of parts based on length, as a sample shot region to be used for substrate alignment; An information processing method characterized by having the following features.
2. The aforementioned selection step is, A step of determining the length of the outer perimeter of the target area, A step of obtaining the division position based on the value obtained by dividing the length obtained above by the predetermined number, The information processing method according to claim 1, which includes the following:
3. The information processing method according to claim 1, characterized in that the selection step involves selecting, as the sample shot region, a shot region located between the shot region to which each division position belongs and two adjacent shot regions, from among the shot regions in contact with the outer periphery.
4. The information processing method according to claim 1, characterized in that the selection step includes dividing the outer perimeter into a predetermined number of parts, starting from the intersection point of the center line extending in a first direction of the target area and the outer perimeter.
5. The information processing method according to claim 4, characterized in that the target area has an outer perimeter shape in which the length of the center line extending in the first direction and the length of the center line extending in a second direction perpendicular to the first direction are different.
6. The information processing method according to claim 5, characterized in that the outer periphery is a rectangle having a long side extending parallel to the first direction and a short side extending parallel to the second direction.
7. The target area has a rectangular outer perimeter shape with a first side extending parallel to the first direction and a second side extending perpendicular to the first direction. The selection step includes dividing the outer perimeter into the predetermined number of parts, starting from one of the four corners of the rectangle. The information processing method according to feature 1.
8. The process further includes creating a plurality of groups consisting of a predetermined number of adjacent shot areas in the target area, The aforementioned selection step is, A step of selecting some groups from the aforementioned plurality of groups that correspond to the division position, The process of selecting one shot region from the aforementioned group as a sample shot region, The information processing method according to claim 1, which includes the following:
9. The information processing method according to claim 1, further comprising the step of changing the sample shot region selected by the selection step to another shot region in which no abnormality is detected.
10. The information processing method according to claim 1, characterized in that the target area is set to an area including the peripheral shot area of the substrate.
11. The information processing method according to claim 1, characterized in that the target area is set to an area excluding the peripheral shot area of the substrate.
12. The information processing method according to claim 1, further comprising a calculation step of performing statistical processing using the measured values of the alignment marks of the sample shot region selected in the selection step.
13. The information processing method according to claim 1, characterized in that the target area is selected based on the layout of shot regions arranged on the substrate.
14. An acquisition process to acquire a target area including multiple shot regions arranged on a rectangular substrate, A selection step of selecting, from among the plurality of shot regions, a shot region corresponding to a division position in which the outer periphery of the target area is divided equally into a predetermined number of parts based on length, as a sample shot region to be used for aligning the substrate; A transmission step of transmitting an image signal that includes information regarding the relative positional relationship between the target area and the sample shot area, An information processing method characterized by having the following features.
15. It has a processing unit, and the processing unit is Acquire the target area which includes multiple shot regions, Of the multiple shot regions, the shot regions corresponding to division positions that equally divide the outer perimeter of the target area into a predetermined number of parts based on length are selected as sample shot regions to be used for substrate alignment. An information processing device characterized by the following:
16. The information processing apparatus according to claim 15, characterized in that the processing unit performs statistical calculations using the measured values of the alignment marks of the selected sample shot area.
17. Processing unit and The system includes a transmitting unit that transmits an image signal based on the processing information obtained by the processing in the aforementioned processing unit, The processing unit acquires a target area including a plurality of shot regions arranged on a rectangular substrate, and selects a shot region from among the plurality of shot regions that corresponds to a division position in which the outer perimeter of the target area is divided into a predetermined number of equal parts based on length, as a sample shot region to be used for aligning the substrate. The information processing apparatus is characterized in that the image signal includes information regarding the relative positional relationship between the target area and the sample shot area.
18. Display unit and The system further includes a display control unit that controls the display of the display unit based on the image signal, The transmitting unit transmits the image signal to the display control unit. The information processing apparatus according to feature 17.
19. An information processing apparatus having a transmitting unit that transmits an image signal containing information about the relative positional relationship between a target area on a rectangular substrate and a sample shot area selected from the target area for aligning the substrate, The information processing apparatus is characterized in that the sample shot area is an area corresponding to a division position in which the outer perimeter of the target area is divided into a predetermined number of equal parts based on length.
20. A substrate stage that holds and moves the substrate, With respect to the substrate held by the substrate stage, a processing unit selects a sample shot area by the information processing method described in any one of claims 1 to 14, The system includes a measuring unit that measures the position of a mark placed in the sample shot area, Based on the measurement results from the measurement unit, the substrate is aligned and a pattern is formed on the substrate. A lithography apparatus characterized by the following features.
21. Display unit and The system includes a display control unit that controls the display of the display unit based on an image signal containing information about the relative positional relationship between a target area on a rectangular substrate and a sample shot area selected from the target area used for aligning the substrate, The aforementioned sample shot region is a region corresponding to a division position that divides the outer perimeter of the target area into a predetermined number of equal parts based on length. A lithography apparatus characterized by the following features.
22. A program for causing a computer to execute each step of the information processing method described in any one of claims 1 to 14.
23. The acquisition process involves acquiring a target area that includes multiple shot regions, A selection step of selecting, from among the plurality of shot regions, a shot region corresponding to a division position in which the outer periphery of the target area is divided equally into a predetermined number of parts based on length, as a sample shot region to be used for substrate alignment; A measurement step of measuring the position of a mark placed in the sample shot area selected in the selection step, A forming step in which a pattern is formed on the substrate while aligning the substrate based on the measurement results in the measurement step, A processing step for processing the substrate on which the pattern is formed, A method for manufacturing an article, characterized by having a processed substrate and manufacturing an article from the substrate.