Determination method, lithography method, article manufacturing method, program, information processing device, and lithography apparatus.

Abstract

This technology offers advantages in terms of alignment accuracy in global alignment. [Solution] A determination method for determining a plurality of sample shot regions to be used for global alignment of a substrate from among a plurality of shot regions on the substrate includes: a setting step of setting a plurality of areas on the substrate, each containing two or more shot regions that are candidates for sample shot regions; an evaluation step of obtaining an evaluation value for evaluating the result of the global alignment for each of a plurality of combinations of which at least one shot region is selected from the plurality of areas; and a determination step of determining the plurality of sample shot regions based on the combination of the plurality of combinations in which the evaluation value satisfies predetermined conditions.

Description

Technical Field

[0001] The present invention relates to a determination method, a lithography method, an article manufacturing method, a program, an information processing apparatus, and a lithography apparatus.

Background Art

[0002] In an exposure apparatus, a plurality of layers of patterns (circuit patterns) are transferred onto a substrate in an overlapping manner. However, if the alignment accuracy between the layers is not good, it may cause problems in circuit characteristics. For example, the chips obtained from the substrate may not meet the predetermined characteristics and become defective products, resulting in a decrease in yield. Therefore, it is necessary to precisely align each of a plurality of shot regions where patterns are to be formed on the substrate with the pattern on the reticle.

[0003] In an exposure apparatus, the position of an alignment mark arranged in each shot region on the substrate is measured, and alignment between each shot region of the substrate and the pattern on the reticle is performed based on the position information of the alignment mark and the position information of the pattern on the reticle. Ideally, high-precision alignment can be achieved by measuring the positions of alignment marks for all shot regions on the substrate, but this is not practical from the perspective of productivity. Therefore, global alignment has become the mainstream for alignment between the substrate and the reticle in exposure apparatuses.

[0004] In global alignment, the position of alignment marks is measured for each of several sample shot regions selected as part of multiple shot regions on the substrate, and the relative positions of these multiple shot regions are determined using the measurement results and a predetermined function model. Specifically, the parameter values ​​of the function model are estimated by performing regression analysis-like statistical calculations on the results of measuring the position of alignment marks for each of the multiple sample shot regions. Then, using the function model to which these parameter values ​​are applied, the position coordinates of each shot region in the coordinate system of the stage that holds the substrate (stage coordinate system) (for example, the arrangement of multiple shot regions on the substrate) are calculated. Based on the position coordinates of each shot region calculated in this way, alignment is performed between each shot region of the substrate and the master plate. In global alignment, a polynomial model with stage coordinates as variables is generally used as the function model, and linear polynomials of stage coordinates such as scaling, rotation, and uniform offset are mainly used. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 6-349707 [Overview of the project] [Problems that the invention aims to solve]

[0006] Patent Document 1 describes a method for changing the sample shot area to a nearby (adjacent) shot area when a specific sample shot area with a large nonlinear error exists. However, since substrate distortion may occur near the specific sample shot area, it may be difficult to guarantee the desired alignment accuracy with the method described in Patent Document 1. Furthermore, if there are variations in distortion among multiple substrates, it may be difficult to guarantee the desired alignment accuracy if a sample shot area set at a common position across multiple substrates is used.

[0007] Therefore, the present invention aims to provide a technology that is advantageous in terms of alignment accuracy in global alignment. [Means for solving the problem]

[0008] To achieve the above objective, a determination method as one aspect of the present invention is a determination method for determining a plurality of sample shot regions to be used for global alignment of a substrate from among a plurality of shot regions on a substrate, characterized in that it includes a setting step of setting a plurality of areas on the substrate, each containing two or more shot regions that are candidates for sample shot regions; an evaluation step of obtaining an evaluation value for evaluating the result of the global alignment for each of a plurality of combinations of which at least one shot region is selected from the plurality of areas; and a determination step of determining the plurality of sample shot regions based on the combination of the plurality of combinations in which the evaluation value satisfies predetermined conditions.

[0009] 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]

[0010] According to the present invention, for example, it is possible to provide a technology that is advantageous in terms of alignment accuracy in global alignment. [Brief explanation of the drawing]

[0011] [Figure 1] Schematic diagram showing an example of the configuration of an exposure apparatus. [Figure 2] Schematic diagram showing an example configuration of the alignment measurement unit. [Figure 3] Flowchart showing the exposure process [Figure 4] A diagram showing an example of the arrangement of multiple shot regions on a substrate. [Figure 5]This figure shows the relationship between the number of sample shot areas and the correction residuals that occur during global alignment. [Figure 6] Flowchart showing a method for determining multiple sample shot areas in the first embodiment [Figure 7] This diagram shows an example of setting multiple candidate areas on a circuit board. [Figure 8] This diagram shows an example of setting multiple candidate areas on a circuit board. [Figure 9] A diagram showing the corrected residuals for each of the multiple combinations. [Figure 10] A diagram showing an example of expanding the candidate area. [Figure 11] A diagram showing an additional method for identifying combinations of shot regions. [Modes for carrying out the invention]

[0012] 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.

[0013] 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.

[0014] The lithography apparatus according to the present invention is an apparatus that performs global alignment of a substrate and controls the movement of the substrate stage based on the result, thereby forming a pattern in each of a plurality of shot regions on the substrate. Examples of the lithography apparatus include an exposure apparatus that exposes a substrate to transfer the pattern of a master (mask) onto the substrate, and an imprint apparatus that forms a pattern in an imprint material on a substrate using a master (mold). Hereinafter, an exposure apparatus will be exemplified and described as the lithography apparatus.

[0015] <First Embodiment> The first embodiment according to the present invention will be described. FIG. 1 is a schematic diagram showing a configuration example of an exposure apparatus 1 of this embodiment. The exposure apparatus 1 is a lithography apparatus used in a manufacturing process of a device such as a semiconductor element, and projects the pattern of a master 2 (reticle, mask) onto a substrate 4 through a projection optical system 3 to expose the substrate 4. Thereby, the pattern of the master 2 can be transferred onto the substrate 4.

[0016] As shown in FIG. 1, the exposure apparatus 1 may include a projection optical system 3 that projects (reduces and projects) the pattern formed on the master 2, and a substrate stage 5 that holds and moves the substrate 4 on which an underlying pattern and alignment marks are formed in a previous process. The substrate stage 5 includes a chuck 5a that holds the substrate 4 and a substrate drive mechanism 5b that drives the substrate 4 by driving the chuck 5a. Further, the exposure apparatus 1 includes an alignment measurement unit 6 that measures the positions of the alignment marks provided on the substrate 4, and a control unit 7.

[0017] The control unit 7 is constituted by, for example, 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 1. In addition to controlling the exposure process for exposing the substrate 4, the control unit 7 of the present embodiment performs global alignment of the substrate 4 and controls the movement of the substrate stage 5 (that is, the driving of the substrate 4) based on the result. Global alignment may be understood as a process for obtaining the arrangement of a plurality of shot regions on the substrate 4. Further, the control unit 7 may be provided with a user interface unit 7a for receiving an input from a user or notifying the user of information.

[0018] FIG. 2 is a schematic diagram showing a configuration example of the alignment measurement unit 6. The alignment measurement unit 6 optically detects alignment marks provided in each shot region of the substrate 4 and measures the positions of the alignment marks. The alignment measurement unit 6 of the present embodiment may include a light source 8, a beam splitter 9, a lens 10, a lens 13, and a sensor 14 (photoelectric conversion element).

[0019] The light from the light source 8 is reflected by the beam splitter 9, passes through the lens 10, and illuminates the alignment mark 11 or 12 on the substrate 4. As an example, the alignment mark 11 is a pre-alignment mark, and the alignment mark 12 is a fine alignment mark. The light diffracted by the alignment mark 11 or 12 passes through the lens 10, the beam splitter 9, and the lens 13, and is received by the sensor 14.

[0020] Hereinafter, the exposure process (lithography process) performed by the exposure apparatus 1 will be described with reference to the flowchart of FIG. 3. Here, the steps until the substrate 4 is aligned and exposed will be described. The flowchart of FIG. 3 can be executed by the control unit 7.

[0021] In step S101, the control unit 7 loads the substrate 4 onto the substrate stage 5 using a transport mechanism (not shown). The substrate 4 loaded onto the substrate stage 5 is held by a chuck 5a. Next, in step S102, the control unit 7 performs pre-alignment. Pre-alignment is a process in which the alignment measurement unit 6 measures the positions of the alignment marks 11 (marks for pre-alignment) on the substrate 4, and roughly determines the position of the substrate 4 based on the measurement results. Specifically, the control unit 7 has the alignment measurement unit 6 measure the positions of the multiple alignment marks 11 provided on the substrate 4, and determines the overall shift and first-order linear components (magnification and rotation) of the substrate 4 based on the measurement results.

[0022] In step S103, the control unit 7 performs fine alignment. Fine alignment is a process in which the alignment measurement unit 6 measures the position of the alignment marks 12 (marks for fine alignment) on the substrate 4, and based on the measurement results, precisely determines the position of the substrate 4 and the position of each shot area of ​​the substrate 4. Specifically, based on the pre-alignment results, the control unit 7 moves the substrate stage 5 to a position where the alignment marks 12 on the substrate 4 can be detected by the alignment measurement unit 6, and has the alignment measurement unit 6 measure the position of the alignment marks 12 on the substrate 4. Then, based on the measurement results of the position of the alignment marks 12, the control unit 7 precisely determines the overall shift and first-order linear components (magnification and rotation) of the substrate 4, as well as the higher-order components of the substrate 4. At this time, the control unit 7 can determine the position of each shot area of ​​the substrate 4 based on the measurement results of the position of the alignment marks 12. Hereafter, the measurement of the position of the alignment marks 12 by the alignment measurement unit 6 may be referred to as "alignment measurement".

[0023] In this embodiment, global alignment is performed during fine alignment. Specifically, the control unit 7 causes the alignment measurement unit 6 to measure alignment marks 12 for multiple sample shot regions selected as part of multiple shot regions on the substrate 4, and based on the measurement results, the control unit 7 can determine the position of each shot region on the substrate 4. In other words, the arrangement of multiple shot regions on the substrate 4 (hereinafter sometimes referred to as the shot arrangement) can be determined.

[0024] In step S104, the control unit 7 controls the exposure of the substrate 4. Specifically, the control unit 7 controls the movement of the substrate stage 5 to position the substrate 4 based on the position of each shot area obtained by fine alignment (global alignment), and exposes each shot area of ​​the substrate 4. As a result, the pattern of the master plate 2 is transferred to each shot area of ​​the substrate 4. Next, in step S105, the control unit 7 uses a transport mechanism (not shown) to remove the substrate 4 from the substrate stage 5. This completes the series of exposure processes.

[0025] One of the performance indicators of the exposure apparatus 1 is the overlay accuracy. In the exposure apparatus 1, multiple layers of patterns (circuit patterns) are transferred onto the substrate 4 by overlapping them. However, if the overlay accuracy between each layer is not good, problems may occur in the circuit characteristics. Therefore, in the exposure apparatus 1, global alignment is performed as an alignment to guarantee the overlay accuracy.

[0026] Global alignment involves measuring the position of each of several sample shot regions selected as part of multiple shot regions on substrate 4, and determining the position of each shot region on substrate 4 based on these measurement results. However, because distortion may occur in substrate 4, it may be difficult to guarantee the desired alignment accuracy depending on the selected sample shot regions. Furthermore, if there are variations in distortion among multiple substrates 4, it may be difficult to guarantee the desired alignment accuracy if sample shot regions set to a common position across multiple substrates 4. In other words, in global alignment, appropriately selecting multiple sample shot regions is crucial for improving alignment accuracy.

[0027] The following describes global alignment. Figure 4 shows an example of the arrangement of multiple shot regions 40 on the substrate 4. In Figure 4, multiple sample shot regions selected as part of the multiple shot regions 40 are indicated by hatching.

[0028] In global alignment, alignment accuracy can be improved by setting more sample shot areas on the substrate 4. However, the number of sample shot areas is in a trade-off relationship with the time required for alignment measurement. In other words, simply increasing the number of sample shot areas may decrease the productivity (throughput) of the exposure apparatus 1. Therefore, in global alignment, it is desirable to set (select) multiple sample shot areas in order to improve alignment accuracy while minimizing the decrease in productivity.

[0029] Figure 5 shows the relationship between the number of sample shot regions and the correction residual generated by global alignment. The correction residual represents the difference between the predicted coordinates and the actual coordinates for each shot region 40 of the substrate 4. Predicted coordinates are the coordinates predicted by applying the correction values ​​obtained from global alignment to the design coordinates. Actual coordinates are the coordinates actually measured by the alignment measurement unit 6. In other words, the correction residual is the difference between the result of measuring the position of the shot region 40 and the result of estimating the position of the said shot region 40 by global alignment. Here, the correction residual may also be understood as representing the difference between the predicted coordinates and the actual coordinates for each mark. In other words, the correction residual may be understood as the difference between the actual coordinates of a mark obtained from alignment measurement and the predicted coordinates of the said mark, which are predicted by applying the correction values ​​calculated from the actual coordinates of the said mark to the design coordinates.

[0030] The correction residual (ResX, ResY) occurring in a certain shot area 40 can be calculated using the following formula. In the following formula, the actual coordinates of the target mark placed in the shot area 40 are (MeasX, MeasY), the design coordinates of the target mark are (DesignX, DesignY), and the correction value is (CompX, CompY). ResX = MeasX - (DesignX × CompX) ResY = MeasY - (DesignY × CompY)

[0031] When accurate correction values ​​are obtained through global alignment, applying these correction values ​​can reduce the correction residual, which is the difference between the actual coordinates and the predicted coordinates. On the other hand, if accurate correction values ​​are not obtained through global alignment, the correction residual will increase, potentially reducing the alignment accuracy. In other words, by calculating (checking) the correction residual, it is possible to determine the validity of the correction values ​​obtained through global alignment. The correction values ​​can be calculated using general coordinate correction calculations (such as linear approximation).

[0032] The following describes a method (determination process) for determining multiple sample shot regions to be used for global alignment from among multiple shot regions 40 on the substrate 4 in this embodiment. Figure 6 is a flowchart of the method for determining multiple sample shot regions in this embodiment. The determination of multiple sample shot regions according to the flowchart in Figure 6 can be performed using at least one substrate 4 from among multiple substrates 4 on which the background pattern and alignment marks 12 have been formed through the same preceding process. For example, it can be performed using the first substrate 4 in a lot containing multiple substrates 4. In this embodiment, the flowchart in Figure 6 is executed by the control unit 7, but it may also be executed by an information processing device (computer) provided outside the exposure apparatus 1.

[0033] In step S201, the control unit 7 sets up multiple candidate areas 30 on the substrate 4, each containing two or more shot areas 40 that are candidates for sample shot areas (setting step). For example, the control unit 7 sets up multiple candidate areas 30 on the substrate 4 based on a set of sample shot areas 41 that are set up in advance, based on design data that shows the shot arrangement of the substrate 4. The "set-up sample shot areas 41" may be understood as sample shot areas that have been used in previous exposure processes, and will be referred to as "reference sample shot areas 41" below.

[0034] Figure 7 shows an example of setting multiple candidate areas 30 on the substrate 4. Based on the design data, the control unit 7 sets multiple candidate areas 30a to 30d such that at least one of the multiple reference sample shot areas 41a to 41d is included in one candidate area 30. In the example in Figure 7, four reference sample shot areas 41a to 41d are set in advance, and multiple candidate areas 30a to 30d are set based on each of the four reference sample shot areas 41a to 41d. Each of the multiple candidate areas 30a to 30d contains five shot areas 40. For example, candidate area 30a includes the reference sample shot area 41a and the surrounding shot areas 42 to 45.

[0035] As shown in Figure 8(a), the control unit 7 defines a range 31 that is a predetermined distance L from the position of the reference sample shot area 41 (e.g., the centroid coordinates), and can set a candidate area 30 that includes a shot area 40 that is at least partially contained within the range 31. Alternatively, the control unit 7 may set a candidate area 30 that includes a shot area 40 that is entirely contained within the range 31, or it may set a candidate area 30 that includes a shot area 40 whose centroid is contained within the range 31. The predetermined distance L can be arbitrarily set based on parameter values ​​such as the dimensions of the substrate 4 and / or the dimensions of the shot area 40, but for example, it may be set to a value that is smaller than the radius of the substrate 4 and larger than the length of the shorter side of the shot area 40. The predetermined distance L may also be a value input by the user via the user interface unit 7a. Figure 8(a) shows an example in which a candidate area 30d is set with reference to the reference sample shot area 41d, and 50 [mm] is used as the predetermined distance L.

[0036] Furthermore, as shown in Figure 8(b), the control unit 7 can also set the candidate area 30 to include the reference sample shot area 41 and the surrounding shot area 40. The surrounding shot area 40 is not limited to a single shot area that radially surrounds the reference sample shot area 41, but may be two or more shot areas. Figure 8(b) shows an example in which the candidate area 30d is set with reference to the reference sample shot area 41d, and the candidate area 30d is set to include the shot area 40 adjacent to the reference sample shot area 41d.

[0037] Steps S202 to S204 are evaluation steps that determine evaluation values ​​for evaluating the results of global alignment for each of the multiple combinations of selecting at least one shot area 40 from each of the multiple candidate areas 30 set in step S201. Each of the multiple combinations is a combination of shot areas 40 that can be selected from the multiple candidate areas 30a to 30d, under the condition that at least one shot area 40 is selected from each of the multiple candidate areas 30a to 30d. The number of shot areas 40 included in each combination may be the same or different for all combinations. For example, in the example in Figure 7, four candidate areas 30a to 30d are set, and each candidate area 30 contains five shot areas. Therefore, when selecting one shot area 40 from each candidate area 30, 625 combinations can be obtained.

[0038] In step S202, the control unit 7 measures the position of each shot region 40 by performing alignment measurements on each shot region 40 of the substrate 4 (measurement step). The control unit 7 may measure the position of only the shot regions 40 included in each of the multiple candidate areas 30a to 30d, or it may measure the position of all shot regions 40 on the substrate 4.

[0039] In step S203, the control unit 7 estimates the position of each shot region 40 for each of the multiple combinations by performing global alignment based on the measurement results in step S202 (estimation step). For example, the control unit 7 uses multiple shot regions 40 included in one combination as multiple sample shot regions and performs global alignment based on the position of each sample shot region measured in step S202. This allows the position of each of the multiple shot regions 40 on the substrate 4 to be estimated. This process is performed for each of the multiple combinations.

[0040] In step S204, the control unit 7 determines an evaluation value for each of the multiple combinations. The evaluation value is a value used to evaluate the result of performing global alignment using each of the multiple combinations, and in this embodiment, it is determined based on the corrected residual of each shot region. For example, the control unit 7 can determine the evaluation value for one combination by calculating the difference between the position of each shot region 40 measured in step S202 and the position of each shot region 40 estimated in step S203 as the corrected residual. The control unit 7 may use the value obtained by summing the corrected residuals of each shot region 40 as the evaluation value, or it may use a representative value (e.g., mean, median, mode) of the corrected residual of each shot region 40 as the evaluation value. Such processing is performed for each of the multiple combinations.

[0041] Here, the evaluation value may be determined based on the corrected residuals of all shot regions 40 on the substrate 4, or it may be determined based on the corrected residuals of only the shot regions included in the multiple candidate areas 30. Furthermore, although the evaluation value was determined based on the corrected residual of each shot region in this embodiment, it is not limited to this. For example, if the distortion (shape) of the substrate 4 can be obtained by performing global alignment, the evaluation value may be determined based on the distortion of the substrate 4.

[0042] In step S205, the control unit 7 identifies a combination from among multiple combinations in which the evaluation value satisfies a predetermined condition. Figure 9 shows the corrected residual as the evaluation value for each of the 10 representative combinations from among the multiple combinations. In Figure 9, the combination number is on the horizontal axis and the corrected residual (e.g., the mean value) is on the vertical axis, and the combinations are arranged in order from the highest corrected residual. Figure 9 also shows the corrected residual obtained when all shot areas 40 included in the multiple candidate areas 30a to 30d are used as the sample shot area.

[0043] Generally, a smaller correction residual improves alignment accuracy, so it is beneficial to have a standard for checking how small the correction residual is. Typically, the correction residual 50 obtained when all shot regions 40 included in multiple candidate areas 30 are used as sample shot regions is close to the correction residual obtained when all shot regions 40 on the substrate 4 are used as sample shot regions. Therefore, the magnitude of the correction residual can be confirmed by comparing the correction residuals obtained for each combination with the correction residual 50 as a standard. Accordingly, the control unit 7 can identify the combination among multiple combinations that has a correction residual closest to the standard correction residual 50 as a combination whose evaluation value satisfies predetermined conditions.

[0044] The control unit 7 can identify combinations among multiple combinations in which the corrected residual is smaller than the specified value Vp as combinations in which the evaluation value satisfies predetermined conditions. In this case, if there are two or more combinations in which the corrected residual is smaller than the specified value Vp, the control unit 7 may select the combination among the two or more combinations in which the distance between shot areas is wider (i.e., the distance between shot areas). Alternatively, the control unit 7 may identify the combination with the smallest corrected residual among multiple combinations as a combination in which the evaluation value satisfies predetermined conditions.

[0045] In step S206, the control unit 7 determines whether a combination satisfying the predetermined conditions for evaluation values ​​was identified in step S205. If a combination satisfying the predetermined conditions for evaluation values ​​is identified, the unit proceeds to step S207. On the other hand, if no combination satisfying the predetermined conditions for evaluation values ​​is identified, the unit returns to step S201, and the control unit 7 repeats steps S201 to S205.

[0046] In step S201 (setting step), which is performed again, the size of at least one candidate area is enlarged so that the number of shot regions 40 within that candidate area increases. For example, the control unit 7 can determine a candidate area among the multiple candidate areas 30a to 30d that includes an abnormal shot region where the correction residual is greater than or equal to a threshold as a candidate area to enlarge. If candidate area 30a includes an abnormal shot region, the control unit 7 enlarges the size of candidate area 30a so that a predetermined number (e.g., 5) of shot regions 46 are added to candidate area 30a, as shown in Figure 10. If other candidate areas 30b to 30d also include abnormal shot regions, the size of the other candidate areas 30b to 30d may be enlarged in the same way as candidate area 30a.

[0047] As mentioned above, by comparing the corrected residuals, a combination in which the evaluation value satisfies predetermined conditions may be identified. In this case, the improvement in the corrected residuals may be slight, and improvement in alignment accuracy by changing the sample shot area may not be expected. Therefore, in this embodiment, the size of at least one of the multiple candidate areas 30a to 30d is expanded so that a predetermined number (e.g., 5) of shot areas 46 are added.

[0048] First, correction residuals are extracted for the reference sample shot regions 41a to 44d in each candidate area 30a to 30d. Next, correction residuals are extracted for each shot region 40 included in each candidate area 30a to 30d. This makes it possible to compare multiple candidate areas 30a to 30d using correction residuals. For example, suppose the user has set a target value of reducing the correction residual by 5.0 nm, and a comparison of correction residuals as shown in Figure 9 shows that only a reduction of 3.5 nm in the correction residual can be expected with the initial size of each candidate area 30a to 30d. According to this embodiment, by adding a shot region 40 to each peripheral region 30a to 30d, the correction residual can be reduced so that the target value is achieved.

[0049] The method for expanding the candidate area 30 is carried out in accordance with the method for setting the candidate area 30 described above. The expansion of the candidate area 30 may be performed on at least one candidate area 30, but it is not necessary to perform it on all candidate areas 30. In addition, in the measurement process that is performed again, when performing alignment measurement on the shot area 40 within each candidate area 30, it may be the case that alignment measurement has already been performed and the actual coordinates of the alignment marks necessary for calculating the corrected residual have been obtained. In this case, the alignment measurement for that shot area can be omitted.

[0050] In step S207, the control unit 7 determines a plurality of sample shot regions based on the combinations identified in step S205 as having evaluation values ​​that satisfy predetermined conditions. For example, the control unit 7 determines a plurality of shot regions 40 included in the combination of evaluation values ​​that satisfy predetermined conditions as a plurality of sample shot regions. The plurality of sample shot regions thus determined are used when performing global alignment of the substrate 4 during the exposure process.

[0051] As described above, in this embodiment, multiple candidate areas 30, each containing two or more shot areas 40 that are candidates for sample shot areas, are set on the substrate 4. Then, an evaluation value is obtained for each of the multiple combinations in which at least one shot area 40 is selected from each candidate area 30, and multiple sample shot areas are determined based on the combinations in which the candidate values ​​satisfy predetermined conditions. By performing global alignment using the multiple sample shot areas determined in this way, the alignment accuracy can be improved.

[0052] <Second Embodiment> A second embodiment of the present invention will now be described. This embodiment is essentially a continuation of the first embodiment, and can be followed in accordance with the first embodiment except for the matters mentioned below.

[0053] Figure 11 shows an additional method for identifying combinations of shot regions 40. While combinations of shot regions 40 can be determined by the results of corrected residuals, if there are two or more combinations with equivalent corrected residuals, i.e., two or more combinations whose evaluation values ​​satisfy predetermined conditions, a decision may be required on which of them to select. Generally, there is a correlation between the alignment accuracy of global alignment and the spread (spacing) between multiple sample shot regions, and the alignment accuracy tends to improve as the spread between the sample shot regions used in global alignment increases. Therefore, in this embodiment, a new indicator, the spread (spacing) between the shot regions 40 in each combination, is added when identifying combinations for determining multiple sample shot regions.

[0054] As an example, the extent of the shot regions 40 in each combination can be represented by the area of ​​the geometric shape (hereinafter sometimes simply referred to as the geometric shape) generated by connecting the centroids of the multiple shot regions 40 included in each combination with straight lines. Figure 11 shows the geometric shapes generated for each of two or more combinations in which the corrected residual is smaller than the reference value Vp. In Figure 11, the geometric shape 51 generated by connecting the centroids of the four shot regions 47 included in one of the two or more combinations is shown, and the geometric shape 52 generated by connecting the centroids of the four shot regions 48 included in the other of the two or more combinations is shown. The control unit 7 compares the two geometric shapes 51 to 52 and identifies the combination corresponding to the geometric shape 52 with the larger area as the combination used to determine multiple sample shot regions.

[0055] <Third Embodiment> A third embodiment of the present invention will now be described. This embodiment is essentially a continuation of the first embodiment, and can be carried out according to the first embodiment except for matters mentioned below. Furthermore, the second embodiment may also be applied to this embodiment.

[0056] In the first embodiment, an example was described in which alignment measurement is performed in the exposure apparatus 1 to determine multiple sample shot areas. In this case, since the alignment measurement is performed using the exposure apparatus 1, the exposure apparatus 1 is occupied, which reduces the productivity of the exposure apparatus 1. On the other hand, by obtaining information on alignment measurement performed in advance, the decrease in productivity of the exposure apparatus 1 can be reduced. In this embodiment, alignment measurement is performed in advance using a measuring device provided outside the exposure apparatus 1. As a result, the control unit 7 of the exposure apparatus 1 can acquire information (results) on the alignment measurement performed by the external measuring device and determine multiple sample shot areas based on that information. As a method for determining multiple sample shot areas, the method described with reference to Figure 6 in the first embodiment can be used. In this case, step S202 may be omitted. This makes it possible to confirm the validity of the arrangement of sample shot areas before running a lot containing multiple substrates 4. Furthermore, it becomes possible to perform exposure processing with high alignment accuracy from the first run of the lot.

[0057] <Embodiment for manufacturing an article> The article manufacturing method according to an embodiment of the present invention is suitable for manufacturing articles such as microdevices, semiconductor devices, and elements having a fine structure. The article manufacturing method of this embodiment includes a step of forming a pattern on a substrate using the above-described lithography apparatus (lithography method), a processing step of processing the substrate on which the pattern has been formed after the formation step, and a manufacturing step of manufacturing an article from the substrate after the processing step. When the lithography apparatus is configured as an exposure apparatus, the formation step may be a step of forming a latent image pattern on a photosensitive agent coated on a substrate by exposing the substrate using the above-described exposure apparatus (exposure method). In this case, the processing step may 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 compared to conventional methods in at least one of the performance, quality, productivity, and production cost of the article.

[0058] <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.

[0059] <Summary of Embodiments> The disclosures herein include at least the following determination methods, lithography methods, article manufacturing methods, programs, information processing devices, and lithography apparatus. (Item 1) A method for determining multiple sample shot regions to be used for global alignment of a substrate from among multiple shot regions on the substrate, A setting step of setting multiple areas on the substrate, each containing two or more shot regions that are candidates for sample shot regions, An evaluation step to determine an evaluation value for evaluating the result of the global alignment for each of the multiple combinations of selecting at least one shot area from the multiple areas, A determination step of determining the plurality of sample shot regions based on the combination of the plurality of combinations in which the evaluation value satisfies the predetermined conditions, A determination method characterized by including the following. (Item 2) The determination method according to item 1, characterized in that, in the evaluation step, for each combination, the evaluation value is determined based on the difference between the result of measuring the position of the shot area and the result of estimating the position of the shot area by the global alignment. (Item 3) The determination method according to item 2, characterized in that, in the determination step, the plurality of sample shot regions are determined based on the combination in which the difference is smaller than a specified value as a predetermined condition. (Item 4) The determination method according to item 2 or 3, characterized in that the determination step involves determining the plurality of sample shot regions based on the combination with the smallest difference as a predetermined condition. (Item 5) The determination method according to any one of items 2 to 5, characterized in that the evaluation step includes a measurement step of measuring the position of a shot area included in each of the plurality of areas, and an estimation step of estimating the position of the shot area by the global alignment. (Item 6) The determination method according to any one of items 1 to 5, characterized in that, in the determination step, if there are two or more combinations in the plurality of combinations in which the evaluation value satisfies the predetermined condition, the plurality of sample shot areas are determined based on the combination of the two or more combinations in which the distance between the shot areas is wider. (Item 7) If there are no combinations that satisfy the predetermined conditions for the evaluation value, the setting step and the evaluation step are repeated. The determination method according to any one of items 1 to 6, characterized in that, in the setting step which is performed again, the size of at least one area is enlarged so that the number of shot areas within at least one of the plurality of areas increases. (Item 8) A lithography method for forming a pattern on a substrate, A lithography method characterized by performing global alignment of a substrate using a plurality of sample shot regions determined from among a plurality of shot regions on the substrate by the determination method described in any one of items 1 to 7. (Item 9) A forming step of forming a pattern on a substrate using the lithography method described in item 8, A processing step for processing the substrate on which the pattern has been formed after the forming step, A manufacturing process for producing an article from the substrate that has undergone the processing step, A method for manufacturing articles, characterized by including the following: (Item 10) A program that causes a computer to execute one of the decision-making methods described in item 1 through 7. (Item 11) An information processing device that performs the determination method described in any one of items 1 through 7. (Item 12) A lithography apparatus for forming patterns in each of multiple shot regions on a substrate, A stage for holding the substrate, The system includes a control unit that performs global alignment of the substrate using a plurality of sample shot regions determined from among the plurality of shot regions by a determination process, and controls the movement of the stage based on the result, The aforementioned decision process is, A setting step of setting multiple areas on the substrate, each containing two or more shot regions that are candidates for sample shot regions, An evaluation step to determine an evaluation value for evaluating the result of the global alignment for each of the multiple combinations of selecting at least one shot area from the multiple areas, The process includes a determination step of determining the plurality of sample shot regions based on the combination of the plurality of combinations whose evaluation value satisfies a predetermined condition, A lithography apparatus characterized by the following features.

[0060] 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]

[0061] 1: Exposure apparatus, 2: Master plate, 3: Projection optical system, 4: Substrate, 5: Substrate stage, 6: Alignment measurement unit, 7: Control unit

Claims

1. A method for determining multiple sample shot regions to be used for global alignment of a substrate from among multiple shot regions on the substrate, A setting step of setting multiple areas on the substrate, each containing two or more shot regions that are candidates for sample shot regions, An evaluation step to determine an evaluation value for evaluating the result of the global alignment for each of the multiple combinations of selecting at least one shot area from the multiple areas, A determination step of determining the plurality of sample shot regions based on the combination of the plurality of combinations in which the evaluation value satisfies the predetermined conditions, A determination method characterized by including the following.

2. The determination method according to claim 1, characterized in that, in the evaluation step, for each combination, the evaluation value is determined based on the difference between the result of measuring the position of the shot area and the result of estimating the position of the shot area by the global alignment.

3. The determination method according to claim 2, characterized in that the determination step involves determining the plurality of sample shot regions based on the combination in which the difference is smaller than a specified value as a predetermined condition.

4. The determination method according to claim 2, characterized in that the determination step involves determining the plurality of sample shot regions based on the combination with the smallest difference as the predetermined conditions.

5. The determination method according to claim 2, characterized in that the evaluation step includes a measurement step of measuring the position of a shot region included in each of the plurality of areas, and an estimation step of estimating the position of the shot region by the global alignment.

6. The determination method according to claim 1, characterized in that, in the determination step, if there are two or more combinations in the plurality of combinations in which the evaluation value satisfies the predetermined condition, the plurality of sample shot areas are determined based on the combination of the two or more combinations in which the distance between the shot areas is wider.

7. If there are no combinations that satisfy the predetermined conditions for the evaluation value, the setting step and the evaluation step are repeated. The determination method according to claim 1, characterized in that in the setting step which is performed again, the size of at least one area is enlarged so that the number of shot areas within at least one of the plurality of areas increases.

8. A lithography method for forming a pattern on a substrate, A lithography method characterized by performing global alignment of a substrate using a plurality of sample shot regions determined from among a plurality of shot regions on the substrate by the determination method described in any one of claims 1 to 7.

9. A forming step of forming a pattern on a substrate using the lithography method described in claim 8, A processing step for processing the substrate on which the pattern has been formed after the forming step, A manufacturing process for producing an article from the substrate that has undergone the processing step, A method for manufacturing articles, characterized by including the following:

10. A program for causing a computer to execute the determination method described in any one of claims 1 to 7.

11. An information processing device that performs the determination method according to any one of claims 1 to 7.

12. A lithography apparatus for forming patterns in each of multiple shot regions on a substrate, A stage for holding the substrate, The system includes a control unit that performs global alignment of the substrate using a plurality of sample shot regions determined from among the plurality of shot regions by a determination process, and controls the movement of the stage based on the result, The aforementioned decision process is, A setting step of setting multiple areas on the substrate, each containing two or more shot regions that are candidates for sample shot regions, An evaluation step to determine an evaluation value for evaluating the result of the global alignment for each of the multiple combinations of selecting at least one shot area from the multiple areas, The process includes a determination step of determining the plurality of sample shot regions based on the combination of the plurality of combinations whose evaluation value satisfies a predetermined condition, A lithography apparatus characterized by the following features.

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