Measurement method, measurement device, lithography apparatus, and production method of article

Abstract

To provide a technique advantageous for realizing high measurement accuracy.SOLUTION: A measurement method includes: a preliminary measurement process of performing preliminary measurements for acquiring signal information obtained by detecting a plurality of targets formed on a substrate while differentiating a parameter value of a measurement parameter over a plurality of times by using measurement light; an acquisition process of acquiring a relation between the parameter value and the signal information on the basis of a result of the preliminary measurements performed over a plurality of times; a determination process of determining a target for which a main measurement should be performed in the plurality of the targets on the basis of the acquired relation; and a main measurement process of performing the main measurement to the determined target.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a metrology method, a metrology apparatus, a lithography apparatus, and an article manufacturing method. [Background technology]

[0002] In lithography equipment, such as exposure devices, used in lithography processes, the alignment accuracy between the shot area on the substrate and the original, as well as the overlay accuracy between different layers on the substrate, are important. One method for improving alignment and overlay accuracy is to select measurement marks and measurement processing conditions that are less susceptible to degradation in measurement accuracy due to changes in the substrate's characteristics. This maximizes the strength and quality of the measurement signal from the measurement marks, enabling high-precision measurements.

[0003] Patent Document 1 describes a method for determining parameter values ​​for measurement parameters with the aim of improving the measurement accuracy of marks formed on a substrate. The method obtains sensitivity, which indicates the change in measurement value relative to a change in parameter value, and determines the parameter value to be adopted based on the sensitivity distribution. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-184422 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the shape or characteristics of a mark formed on a substrate change, the strength and quality of the measurement signal from the mark may decrease, resulting in a decrease in measurement accuracy.

[0006] An object of the present invention is to provide an advantageous technique for achieving high measurement accuracy. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided a measurement method comprising: a preliminary measurement step of performing preliminary measurements using measurement light to detect multiple targets formed on a substrate and obtain signal information, the preliminary measurements being performed multiple times while varying parameter values ​​of measurement parameters; an acquisition step of obtaining a relationship between the parameter values ​​and the signal information based on the results of the preliminary measurements performed multiple times; a determination step of determining a target from the multiple targets on which main measurement should be performed based on the obtained relationship; and a main measurement step of performing main measurement on the determined target. [Effects of the Invention]

[0008] According to the present invention, an advantageous technique for achieving high measurement accuracy is provided. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing the configuration of a measurement device. [Figure 2] 1A and 1B show examples of sample areas on a substrate. [Figure 3] 10A and 10B are diagrams showing an example of the configuration of a measurement pattern and an example of derivation of a measurement value. [Figure 4] FIG. 2 is a diagram for explaining a center wavelength and a wavelength width as measurement parameters. [Figure 5] 10 is a flowchart showing a sequence of a measurement process. [Figure 6] FIG. 10 is a diagram for explaining a measurement process. [Figure 7] 10A and 10B are diagrams for explaining a method for determining measurement processing conditions based on the relationship between measurement parameters and signal information. [Figure 8] FIG. 10 is a diagram for explaining a method for determining a processing region, which is a measurement processing condition. [Figure 9] FIG. 10 is a diagram for explaining estimation of an overlay measurement value. [Figure 10] 10 is a flowchart showing a sequence of a measurement process. [Figure 11]10 is a flowchart showing a sequence of a measurement process. [Figure 12] FIG. 10 is a diagram for explaining a method for determining a processing region, which is a measurement processing condition. [Figure 13] 10 is a flowchart showing a sequence of a measurement process. [Figure 14] FIG. 1 is a diagram showing the configuration of an exposure apparatus. [Figure 15] 10 is a flowchart showing the sequence of an exposure process. DETAILED DESCRIPTION OF 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 scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0011] First Embodiment FIG. 1(a) is a diagram showing the configuration of a measurement apparatus 100 according to an embodiment. In this specification and the drawings, directions are indicated in an XYZ coordinate system in which the horizontal plane is the XY plane. Generally, a substrate 73 is placed on a substrate stage WS so that its surface is parallel to the horizontal plane (XY plane). Therefore, in the following description, the directions that are perpendicular to each other in a plane along the upper surface of the substrate stage WS on which the substrate 73 is placed are referred to as the X-axis and Y-axis, and the direction perpendicular to the X-axis and Y-axis is referred to as the Z-axis. In the following description, the directions parallel to the X-axis, Y-axis, and Z-axis in the XYZ coordinate system are referred to as the X-direction, Y-direction, and Z-direction, respectively.

[0012] The measurement apparatus 100 may be configured as a detection apparatus that measures or detects the position of a target formed on the substrate 73. Alternatively, the measurement apparatus 100 may be configured as an overlay inspection apparatus that measures the relative positions of multiple targets provided on different layers of the substrate 73. The target may be a mark or a pattern formed on the substrate 73. The pattern may be a pattern formed solely for the purpose of being used as a mark, or may be a predetermined device pattern. Hereinafter, the measurement object used as the target will be referred to as a "pattern." The measurement apparatus 100 has a substrate stage WS that holds the substrate 73, an imaging unit 50 (measurement unit), a control unit 11, and an interface 12.

[0013] The substrate 73 can be used, for example, to manufacture devices such as semiconductor elements and liquid crystal display elements. The substrate 73 can be, for example, a wafer or a glass substrate. The substrate stage WS holds the substrate 73 via a substrate chuck (not shown) and can be driven or positioned by a substrate driving mechanism (not shown). The substrate driving mechanism includes a linear motor or the like, and can move the substrate 73 held by the substrate stage WS by driving the substrate stage WS in the X, Y, and Z directions and in rotational directions around each axis. The position of the substrate stage WS is monitored, for example, by a six-axis laser interferometer 13, and the substrate stage WS is driven to a predetermined position under the control of the control unit 11.

[0014] The control unit 11 is composed of a computer (information processing device) including a CPU, memory, etc., and comprehensively controls the components of the measurement apparatus 100 according to, for example, a program stored in the storage unit. The control unit 11 can perform various correction processes (arithmetic processing) based on the measurement results obtained by the imaging unit 50, specifically, on the image obtained by capturing an image of a measurement pattern formed on the substrate 73. The interface 12 can include a display device, an input device, etc. Through the interface 12, the user can specify the position of a shot area to be measured or a measurement pattern within that shot area, among multiple shot areas formed on the substrate 73.

[0015] The configuration of the imaging unit 50 will be described with reference to FIG. 1(b). The imaging unit 50 may include an illumination system that illuminates a substrate 73 using light from a light source 61, and an imaging system (detection system) that forms an image of a measurement pattern 72 formed on the substrate 73 on an imaging element 75. Light from the light source 61 is directed to an illumination aperture stop 64 via lenses 62 and 63. The light source 61 may be, for example, a laser light source, an LED, or a halogen lamp, but is not limited to these. The light that passes through the illumination aperture stop 64 is directed to a polarizing beam splitter 68 via a lens 65, a mirror 66, and a lens 67. P-polarized light that passes through the beam splitting surface of the polarizing beam splitter 68 passes through an aperture stop 69 and is converted to circularly polarized light by a λ / 4 plate 70. The P-polarized light then passes through an aperture stop 69 and Kohler-illuminates the measurement pattern 72 formed on the substrate 73 via an objective lens 71.

[0016] The light that has been Koehler illuminated and is reflected, diffracted, and scattered by measurement pattern 72 passes through objective lens 71 and λ / 4 plate 70 and is directed to aperture stop 69. Here, the polarization state of the light from measurement pattern 72 becomes circularly polarized in the opposite direction to the circularly polarized light that Koehler illuminates measurement pattern 72, and is converted from circularly polarized light to S-polarized light by passing through λ / 4 plate 70. After passing through aperture stop 69, this S-polarized light is reflected by the beam splitting surface of polarizing beam splitter 68 and is directed to image sensor 75 via lens 74.

[0017] The illumination optical system may be provided with a light intensity adjustment unit (not shown) and a wavelength adjustment unit (not shown). The light intensity adjustment unit may include, for example, a plurality of ND filters having different transmittances for the light from the light source 61. The plurality of ND filters are arranged in a switchable state. The light intensity adjustment unit can adjust the intensity of the light illuminating the substrate 73 by controlling the switching of the ND filters.

[0018] The wavelength adjustment unit may include, for example, a wavelength tunable element and a drive mechanism that drives the wavelength tunable element. The drive mechanism may include a linear motor or the like, and may adjust the wavelength (e.g., center wavelength and wavelength width) of the light (measurement light) that illuminates the measurement pattern 72 by driving the wavelength tunable element along a predetermined direction (e.g., the X direction).

[0019] In addition to the wavelength filters and wavelength-tunable elements described above, other methods for changing the wavelength of light from measurement pattern 72 include using a color sensor or multispectral sensor in which a different wavelength filter is arranged for each pixel. Furthermore, there are also methods using a hyperspectral sensor equipped with a diffractive optical element, or a multi-camera equipped with wavelength division means such as a dichroic prism and multiple image sensors. In this way, light of multiple different wavelengths may be detected from measurement pattern 72 using image sensor 75.

[0020] The control unit 11 can acquire the position of the measurement pattern 72 based on position information of the substrate stage WS obtained by the laser interferometer 13 and a signal waveform obtained by detecting an image of the measurement pattern 72. The intensity of the signal waveform can be adjusted by at least one of controlling a light amount adjustment unit (ND filter) provided in the illumination optical system of the imaging unit 50, controlling the output of the light source 61, and controlling the accumulation time of the imaging element 75.

[0021] In the imaging system of the image capture unit 50, the detection aperture stop may be configured by placing multiple lenses between the polarizing beam splitter 68 and the image sensor 75. Alternatively, the illumination aperture stop 64 and the detection aperture stop may each be provided with multiple aperture stops that can set different numerical apertures for the illumination system and the imaging system, and these multiple aperture stops may be switchable. This makes it possible to adjust the σ value, which is a coefficient that represents the ratio of the numerical aperture of the illumination system to that of the imaging system. Furthermore, light from the measurement pattern 72 may be detected using dark-field detection, in which the aperture diameter of the illumination aperture stop 64 or the detection stop is controlled to block zero-order diffracted light from the measurement pattern 72 and detect only higher-order diffracted light and scattered light.

[0022] The following describes a method for capturing an image of a measurement pattern formed on a substrate 73 using the measurement device 100 and measuring the position of the substrate 73. FIGS. 2(a) and 2(b) are diagrams showing sample areas among a plurality of shot areas formed on the substrate 73. Position measurement for the measurement pattern is performed for the measurement pattern within each sample area. Here, the sample area refers to the combined area of ​​the area where the device pattern is formed and the area including the scribe line nearby. The selection of sample areas shown in FIGS. 2(a) and 2(b) is an example, and the number and positions of the sample areas may be changed as desired depending on the required substrate position measurement accuracy and throughput.

[0023] 3(a) is a diagram showing an example of a measurement pattern 72 formed on a substrate 73. The measurement device 100 normally acquires position information in the X and Y directions for the substrate 73, but for simplicity, only an X pattern for measuring the position in the X direction will be used here.

[0024] In this embodiment, measurement pattern 72 may include multiple different patterns. Measurement patterns 72A and 72B may be patterns (line-and-space patterns) composed of multiple line elements. For example, measurement pattern 72 may include measurement pattern 72A composed of line elements A11 to A14 and measurement pattern 72B composed of line elements A21 to A24. A line-and-space pattern may have spaces between adjacent line elements. For example, as shown in FIG. 3(a), measurement patterns 72A and 72B each have a configuration in which line elements having widths W1 and W2, respectively, and spaces having widths W3 and W4, respectively, are periodically repeated. Measurement patterns 72A and 72B differ in the width of at least one of the line elements and spaces. Furthermore, it is preferable that at least one of the following be different: the pattern design, the number of patterns, the position in the Z direction formed on the substrate, etc., in addition to the widths of the line elements and spaces. The number of measurement patterns 72 is not limited to a specific number; three or more measurement patterns may be used.

[0025] In FIG. 3(a), area 75W indicates the imaging area of ​​image sensor 75 of imaging unit 50. Substrate 73 is aligned with image sensor 50 so that measurement pattern 72 fits within area 75W. This allows light from multiple different measurement patterns to be detected simultaneously. Measurement pattern 72 is then roughly measured, and based on the results of the rough measurement, control unit 11 sets multiple different processing areas in image sensor 75. This allows, for example, position information for each of measurement patterns 72A and 72B to be acquired by setting processing areas 75WA and 75WB for measurement patterns 72A and 72B, respectively, and performing measurements.

[0026] FIG. 3(b) shows the results of photoelectrically converting the signal intensity in the X direction on the surface of the image sensor (not shown) after capturing an image of measurement pattern 72A with image sensor 75. S72A is signal intensity information including two peak signals PA11-PA14 corresponding to line elements A11-A14, respectively. From signal intensity information S72A, a measurement value M1A of measurement pattern 72A relative to the reference position of image sensor 75 can be determined. A measurement value M2A of measurement pattern 72A can be determined in a similar manner for measurement pattern 72B. Note that measurement value M1A is not limited to a measurement value relative to the reference position of image sensor 75; for example, a measurement value relative to a predetermined measurement template or design value may also be used.

[0027] Next, the measurement parameters will be described. The measurement device 100 can preferably perform measurement according to a set parameter value for each of at least one parameter. The at least one measurement parameter can include at least one of the central wavelength, wavelength width, σ value, and polarization characteristics of the light (measurement light) that illuminates the measurement pattern. The polarization characteristics can be the polarization characteristics in the optical path of the measurement device 100 or the measurement unit. The at least one measurement parameter can also include various calculation processing parameters that are set when the control unit 11 calculates a measurement value from image information of the measurement pattern.

[0028] The following describes, as an example, measurement parameters related to the wavelength of light used in measurement. Examples of measurement parameters related to the wavelength of light used in measurement include the central wavelength and wavelength width. Fig. 4(a) is a diagram showing the wavelength characteristics of light having different central wavelengths, where the two different central wavelengths are indicated as WL1 and WL2. Fig. 4(b) is a diagram showing the wavelength characteristics of light having the same central wavelength but different wavelength widths, where the two different wavelength widths are indicated as ΔWL1 and ΔWL2.

[0029] The characteristics of the measurement pattern on the substrate, such as the material properties, structure, shape, etc., may vary depending on the process used to obtain the substrate. Therefore, in order to achieve high-precision measurements, it is important to adapt the measurement parameters to the characteristics of the measurement pattern.

[0030] However, the characteristics of the measurement pattern can vary locally. For example, the characteristics of the measurement pattern vary depending on the measurement pattern and the characteristic portions (pattern features) that make up the measurement pattern. Even if center wavelength WL1 is the optimal measurement parameter value for line element A11, this does not necessarily mean that center wavelength WL1 is the optimal measurement parameter value for line element A14. For this reason, when measuring measurement pattern 72 as the processing area, it is difficult to accurately determine the optimal measurement parameter value.

[0031] Therefore, in this embodiment, first, a preliminary measurement is performed multiple times with different parameter values ​​of measurement parameters to obtain signal information by detecting an image of a target formed on a substrate (preliminary measurement). Then, based on the results of the preliminary measurements performed multiple times, a relationship between the parameter values ​​and the signal information is obtained. Next, based on the obtained relationship, a processing region within the substrate where main measurement should be performed is determined. Then, main measurement is performed on the determined processing region.

[0032] The sequence of the measurement process of this embodiment will be described below with reference to Fig. 5. The measurement process is performed by the control unit 11 controlling each unit of the measurement device 100 in an integrated manner.

[0033] In S501, the control unit 11 transports the substrate 73 within the measurement range of the imaging unit 50, and pre-aligns the substrate 73 so that the X-direction running of the substrate stage WS coincides with the X-direction arrangement direction of the multiple shot areas exposed on the substrate 73.

[0034] In S502, the control unit 11 acquires signal information from the measurement pattern 72 while varying at least one measurement parameter. Here, the signal information can be at least one of contrast, signal intensity information, and position information as a signal evaluation value obtained from the image. The signal evaluation value will be described later.

[0035] In S503, the control unit 11 obtains the signal information data for the change in the measurement parameter obtained in S502. The signal information data for the change in the measurement parameter will be described later.

[0036] In S504, the control unit 11 may determine measurement processing conditions based on the data obtained in S503. The measurement processing conditions may be, for example, at least one of a processing area, a sample area, and measurement parameters. Here, the processing area is a processing area corresponding to a line element. For example, multiple processing areas may be set according to the number of line elements. In this case, a weight to be assigned to each processing area may also be determined. Similarly, a processing area may be set for each of multiple different measurement patterns, and a weight to be assigned may also be determined.

[0037] In S505, the control unit 11 sets the measurement processing conditions in accordance with the measurement processing conditions determined in S504. The measurement processing conditions are set, for example, by storing the measurement processing conditions in a predetermined area in the storage unit.

[0038] In S506, the control unit 11 acquires the position information of the measurement pattern 72, and calculates the position of the substrate 73 by statistically processing the position information.

[0039] The signal evaluation value will be described below. The signal evaluation value is an index indicating the quality of signal intensity information generated based on the output of the imaging element 75 (imaging unit 50). FIG. 6(a) is a diagram illustrating the reflected light from the measurement pattern 72 and the non-patterned portion in a cross section of a substrate 73. The substrate 73 is composed of a first layer L1 and a second layer L2, and has two boundary surfaces S1 and S2. At boundary surface S1, the measurement pattern 72 has a step of height d relative to the non-patterned portion. The reflected light from the measurement pattern 72 at boundary surface S1 is designated L1A, the reflected light from the non-patterned portion is designated L1B, and the reflected light from the measurement pattern 72 and the non-patterned portion at boundary surface S2 are designated L2A and L2B, respectively. In the imaging unit 50, the interference light between the reflected light L1A and L2A and the interference light between the reflected light L1B and L2B become the reflected light LA ​​from the measurement pattern 72 and the reflected light LB from the non-patterned portion, and are detected, respectively.

[0040] FIG. 6(b) is a diagram showing an example of signal intensity information for position X, including reflected light LA ​​from the patterned portion shown in FIG. 6(a) and reflected light LB from the non-patterned portion. Here, the smaller the difference in signal intensity between reflected light LA ​​and LB, the lower the signal contrast, making it more difficult to detect the position of the measurement pattern. The difference in signal intensity between reflected light LA ​​and LB varies depending on the phase difference Δ caused by the step d of measurement pattern 72, and the phase difference Δ is expressed by the following (Equation 1) using the refractive index n of second layer L2, the step d, and the wavelength λ.

[0041] Δ=2nd×2π / λ (Equation 1) According to (Equation 1), the phase difference Δ changes when there is variation in the refractive index n or step height d of the second layer L2 in the measurement pattern 72. As described above, a change in the phase difference Δ causes a change in the signal contrast, which may result in measurement errors and reduced measurement accuracy.

[0042] Figure 6(c) shows an example of signal intensity information for a pattern, with the horizontal axis representing position and the vertical axis representing signal intensity. Due to differences in the structure of the substrate between the patterned and non-patterned areas, differences in signal intensity occur depending on the position. One example of characteristic information for a measurement pattern is a quantified value for the contrast of the measurement signal.

[0043] For example, in Fig. 6(c), the maximum signal strength in the left section of the measurement signal is T L , the minimum value is B L The maximum signal strength in the right section is T R , the minimum value is B R Then, the contrast EC in the measurement signal may be calculated as characteristic information, as shown in the following (Equation 2).

[0044] EC={(T L -B L ) / (T L +B L )+(T R -B R ) / (T R +B R )} / 2 (Formula 2) Alternatively, for example, asymmetry ES in the measurement signal may be obtained as characteristic information, as shown in Fig. 6(d). The asymmetry of the measurement signal can be calculated according to the following (Equation 3).

[0045] ES=(T L -B L ) / (T L +B L )-(T R -B R ) / (T R +B R ) (Formula 3) The method for calculating the asymmetry is not limited to (Equation 3). For example, the center position of the measurement signal may be defined, and the asymmetry of the measurement signal may be defined based on the signal strength in a predetermined position range in the left and right sections relative to the center position.

[0046] 7 and 8, a method for determining measurement processing conditions based on the relationship between the measurement parameters and signal information in S503 and S504 will be described. First, as an example, a method for determining measurement processing conditions will be described when the measurement parameter is the center wavelength and the signal information is the contrast of each of multiple line elements. An example of determining a processing region as a measurement processing condition will also be described. Data on the contrast relative to changes in center wavelength serves as an index for determining the measurement processing conditions to be used for measurement in S507.

[0047] FIG. 7(a) shows the relationship between contrast and center wavelength as signal information of measurement pattern 72A obtained in processing area 75WA (FIG. 3(a)). The horizontal axis represents center wavelength (labeled "wavelength"), and the vertical axis represents the contrast of measurement pattern 72A. Here, center wavelengths WL3 and WL4 refer to the central wavelengths of light. According to FIG. 7(a), the contrast of measurement pattern 72A at center wavelength WL3 is C3a, and the contrast at center wavelength WL4 is C4a. Here, the contrast of measurement pattern 72A is the average of the contrast values ​​obtained from peak signals PA11 to PA14 (FIG. 3(b)). Then, for example, it is determined whether the obtained contrast value (the maximum value) exceeds a threshold value SH. The threshold value SH can be determined, for example, using characteristic information and position information of multiple substrates obtained in advance. As described above, selecting measurement parameter values ​​can reduce measurement errors associated with process changes. Furthermore, when selecting measurement parameter values ​​from position information rather than measurement pattern signal information, parameter values ​​with low sensitivity to changes in the measurement value in response to changes in the measurement parameter may be selected.

[0048] FIG. 7(b) shows the relationship between the center wavelength and contrast for each of the line elements A11 to A14 of the measurement pattern 72A. Even with the same measurement pattern, differences in film unevenness and shape due to the process can occur for each pattern. Therefore, it is necessary to determine whether the contrast value (maximum value) for each of the multiple line elements exceeds the threshold value SH. According to FIG. 7(b), the contrast values ​​(e.g., maximum contrast values) of the line elements A11, A12, and A13 exceed the threshold value SH, but the contrast value of the line element A14 does not reach the threshold value SH. Therefore, an area excluding the line element A14, such as the processing area 75WC shown in FIG. 8, is set as the processing area (as a measurement processing condition). Here, multiple line elements are used as an example, but processing areas may also be set for multiple measurement patterns or device patterns that differ in pattern design, number of line elements, or Z-direction position formed on the substrate.

[0049] In the above determination method, the target has a pattern including a plurality of line elements, the measurement parameter is the central wavelength of light illuminating the measurement pattern, and the signal information is the contrast of each of the plurality of line elements. In the above determination method, a relationship between the central wavelength and the contrast for each of the plurality of line elements is acquired. Then, among the plurality of line elements, line elements whose maximum contrast value in the relationship does not meet a threshold value are excluded from the measurement.

[0050] (How to determine the sample area) The above describes a method for determining a processing area as a measurement processing condition when the measurement parameter is the center wavelength and the signal information is the contrast. Next, a method for determining a sample area as a measurement processing condition when the measurement parameter is the center wavelength and the signal information is the asymmetry of the measurement signal will be described. Here, the multiple targets are patterns made up of multiple line elements, and are arranged in each of multiple predetermined shot areas on the substrate 73, each of which is set as a sample area candidate.

[0051] Figure 7(c) is a diagram showing the relationship between the center wavelength and the asymmetry of the measurement signal obtained in each of the shot areas 151 to 154 (Figure 2(a)). The horizontal axis represents the center wavelength, and the vertical axis represents the asymmetry of the measurement signal. Since the asymmetry of the measurement signal in each sample area can cause measurement errors, it is desirable that it be small. Therefore, a determination is made as to whether the magnitude of the asymmetry of the measurement signal exceeds a threshold value SH, and the sample area is set based on the determination result. For example, in Figure 7(c), the minimum value of the asymmetry of the measurement signal in shot area 154 exceeds the threshold value SH. Therefore, shot area 154 is excluded from the sample area.

[0052] By carrying out the above-described determination method, it is possible to reduce measurement errors that occur due to process changes and achieve highly accurate position measurement.

[0053] The following describes processing when the weights used to calculate the position of measurement pattern 72 for each of line elements A11 to A14 shown in Figure 8 are used as measurement processing conditions. Here, the pattern position is expressed as a weighted average of the positions of multiple line elements. For example, if the weighting coefficients for the pattern positions (PA11 to PA14) are N11 to N14 and the position of measurement pattern 72A is P72A, then position P72A of measurement pattern 72A can be calculated using the following equation: P72A=(N11·PA11+N12·PA12+N13·PA13+N14·PA14) / 4 (Formula 4)

[0054] Alternatively, for example, weighting may be applied to the different patterns 72A and 72B that make up measurement pattern 72. Furthermore, weighting may be applied to the multiple measurement patterns 72 formed at different positions on the substrate. This makes it possible to accurately determine the position of the measurement pattern in relation to process changes within the region of measurement pattern 72 or at the position on the substrate.

[0055] According to the above determination method, the relationship between the center wavelength and the asymmetry of the measurement signal is acquired for each of a predetermined number of shot areas that are sample area candidates, and then, of the predetermined number of shot areas, any shot area for which the minimum value of the asymmetry in the relationship exceeds a threshold is excluded from the sample area candidates.

[0056] Hereinafter, a method for calculating weighting coefficients based on acquired overlay measurement values ​​will be described as one method.

[0057] 9 is a diagram showing the relationship between a pattern, a position correction amount (position correction coefficient) of a substrate 73 based on the pattern, and an overlay measurement value of the formed pattern. For example, the position correction amount GA11 of the substrate means a result calculated by performing global alignment based on the position measurement result of a line element A11. Also, the overlay measurement value OLA means a result obtained by forming a pattern on the substrate based on the position correction amount GA11 of the substrate.

[0058] When the position measurement result of the pattern A12 is used, the overlay measurement value OLB can be estimated from the following equation based on the substrate position correction amounts GA11 and GA12 and the overlay measurement value OLA.

[0059] OLB=OLA+F(GA11,GA12) (Formula 5) Here, F(GA11, GA12) represents a function including GA11 and GA12. As a typical example, F(GA11, GA12) can be GA11-GA12. In this case, the overlay measurement value OLB is calculated as a value obtained by adding the difference between the substrate position correction amounts GA11 and GA12 to the overlay measurement value OLA. Specific examples of the position correction amount include substrate positional deviation (shift), magnification error, and rotation error. In the calculation process, it is preferable to calculate each of the difference values ​​of the position correction amounts and add the difference values ​​of the position correction amounts to multiple shot areas on the substrate 73.

[0060] In the measurement apparatus of this embodiment, a processing area is set for each of the multiple line elements that make up the measurement pattern within the image capture area obtained from the image capture unit 50, and the position of the substrate is measured. Then, based on the measurement values ​​obtained for each processing area, a position correction amount for the substrate is calculated. Therefore, the position correction amount for the substrate corresponding to the multiple different processing areas is calculated, and it is possible to estimate overlay measurement values ​​corresponding to the multiple different processing areas based on position information of the pattern formed on the substrate.

[0061] The weighting coefficient assigned to each processing area (i.e., each line element in the measurement pattern) is preferably determined so that the overlay measurement value for multiple shot areas on the substrate is equal to or less than a tolerance (e.g., minimum). Alternatively, the weight may be set as a parameter to calculate a weighting coefficient that will result in an overlay measurement value that is equal to or less than a tolerance (e.g., minimum). In one example, setting a processing area that includes only one of multiple line elements included in the measurement pattern is performed by setting the weighting coefficient for that one line element to 1 and setting the weighting coefficients for the other line elements to 0. Note that weighting coefficients are not limited to positive numbers, and negative numbers may also be assigned.

[0062] As yet another method, the difference between the acquired position information of the pattern and the design value (target value) may be calculated, and the weighting coefficient may be set so as to minimize the difference. As yet another method, the weighting coefficient may be set based on the signal information of the acquired measurement pattern and the number of line elements. Furthermore, the weighting coefficient may be set so as to minimize the variation in signal information among multiple shot areas on the substrate 73.

[0063] Here, in S505, the weighting coefficients assigned to the multiple line elements that make up the measurement pattern do not need to be the same for all sample areas on substrate 73. For example, the weighting coefficients may be set differently depending on the position of the sample area relative to substrate 73. Furthermore, the weighting coefficients do not need to be the same for the measurement direction on substrate 73; for example, different weighting coefficients may be set for measurements in the X and Y directions. In this way, the weighting coefficients for the multiple line elements that make up the measurement pattern are determined.

[0064] Specific statistical processing regarding the pattern position measurement in S506 will be described. For example, the positions of multiple shot areas formed on substrate 73 may be calculated by performing global alignment measurement based on position information of measurement patterns in multiple sample areas.

[0065] In this embodiment, pattern position measurement may be performed by the control unit 11, but is not limited to this. For example, pattern position measurement may be performed by an online host device that performs integrated control over a network, including other devices in the factory where the measuring device 100 is installed. Furthermore, the position measurement results may be transferred, for example, through the online host to an exposure device that performs exposure of the substrate 73 in the next process.

[0066] As described above, in the first embodiment, the light from the pattern formed on the substrate is captured, the relationship between the measurement parameters and the signal information is acquired, and the measurement processing conditions are determined based on the acquired relationship. By calculating the position of the substrate according to the measurement processing conditions, the measurement target can be measured with high accuracy.

[0067] Second Embodiment As a second embodiment, a measurement apparatus and method for measuring the quality of a measurement pattern formed on a substrate or the line elements that make up the pattern will be described.

[0068] First, the function of the measurement device (measurement pattern monitor) will be described. In order to align the substrate 73 with high precision and form a device pattern at the desired position, it is important to detect whether or not there is a change in the characteristic information of the substrate (shape, structure, physical properties, etc.). If the characteristics of the substrate change more than expected, the measurement values ​​of the measurement pattern will change, and the alignment accuracy of the substrate and the overlay accuracy of the pattern on the substrate may decrease. Therefore, the measurement device measures (monitors) the measurement pattern and the pattern characteristics to detect whether or not there is an abnormality on the substrate. If the measurement device detects an abnormality on the substrate, it can issue a warning, error notification, etc.

[0069] In this embodiment, the measurement pattern formed on the substrate is not limited to an alignment pattern or an overlay measurement pattern, but may be, for example, a device pattern.

[0070] The measurement process in the second embodiment will be described with reference to FIG. 10. The difference between the second embodiment and the first embodiment is that signal information of a measurement pattern formed on a substrate is acquired and comparison and determination are performed, so this part will be described in detail. The other parts have the same configuration as the first embodiment, so their description will be omitted. Matters not mentioned here may follow the first embodiment. S1001 to S1006 shown in FIG. 10 are the same as S501 to S506 shown in FIG. 5, so their description will be omitted here.

[0071] In S1006, the control unit 11 acquires signal information of the measurement pattern 72, calculates the difference (pattern quality) from the reference data, and determines whether the difference is equal to or less than a tolerance. The reference data may be data based on characteristic information or position information of multiple substrates that has been calculated in advance. The tolerance may also be set to a value based on the amount of variation among multiple substrates that has been calculated in advance, or the shape of the substrate (grid distortion) necessary to achieve the overlay target.

[0072] Furthermore, the measurement pattern monitor of the second embodiment differs from the first embodiment in the method of determining measurement process conditions. To set measurement process conditions for accurately detecting changes in substrate characteristics, it is preferable that the acquired signal information changes sensitively in response to changes in substrate characteristics. In the method of determining measurement process conditions of this embodiment, measurement process conditions are set to maximize the asymmetry and contrast variation of the measurement signals in multiple sample areas on the substrate. Here, the measurement process conditions may be measurement parameters, processing areas, or weighting coefficients for multiple line elements that make up the measurement pattern. Furthermore, measurement process conditions may be selected to maximize the sensitivity of changes in measurement values ​​to changes in measurement parameters.

[0073] The obtained pattern quality or grid distortion may be transmitted (feedback) via an online host to equipment performing known processes (oxidation, film formation, deposition, doping, planarization, etching, resist stripping, etc.) for quality control.

[0074] As described above, in the second embodiment, the light from the pattern formed on the substrate is captured, the relationship between the measurement parameters and the signal information is obtained, and the measurement processing conditions that are sensitive to changes in the characteristics of the substrate are determined based on the obtained relationship. In this way, the pattern quality can be detected with high accuracy.

[0075] <Third embodiment> As a third embodiment, a measurement method for measuring the position of a substrate and monitoring the quality of a pattern formed on the substrate will be described.

[0076] First, the function of the measurement device (measurement pattern monitor) will be described. As described above, the following is important in order to align the substrate 73 with high precision and form the device pattern at the desired position. Select measurement parameter values ​​that minimize measurement errors due to process changes, and -Detecting whether or not there are any changes in the characteristic information of the board (shape, structure, physical properties, etc.).

[0077] The measurement method in the third embodiment will be described with reference to FIG. 11. The difference between the third embodiment and the first and second embodiments is that alignment measurement and measurement pattern monitoring are performed simultaneously with high accuracy, so this aspect will be described in detail. The other aspects have the same configuration as the first and second embodiments, so their description will be omitted here. Items not mentioned here can follow the first and second embodiments.

[0078] Fig. 11 is a diagram showing a measurement sequence in the third embodiment. Steps S1101 to S1105 shown in Fig. 11 are the same as steps S501 to S505 shown in Fig. 5, and therefore a description thereof will be omitted here.

[0079] In step S1106, signal information of measurement pattern 72 is acquired, and substrate position measurement and determination of whether pattern quality is within an acceptable range are performed in parallel. In the third embodiment, measurement processing conditions must be set to conditions that are insensitive to changes in substrate characteristics and conditions that are sensitive to changes in substrate characteristics. For example, as shown in FIG. 12, processing region 75WC is set to an area that includes only patterns that have small (insensitive) measurement errors due to process changes. On the other hand, processing region 75WC' is set to an area that includes only patterns that have large (sensitive) measurement errors due to process changes. In this way, the signal information obtained from processing region 75WC can be used to measure the position of the measurement pattern with high accuracy, and the signal information obtained from processing region 75WC' can be used to detect pattern quality with high accuracy.

[0080] As described above, in the third embodiment, the light from the pattern formed on the substrate is captured, the relationship between the measurement parameters and the signal information is obtained, and measurement processing conditions that are sensitive to changes in the substrate characteristics and measurement processing conditions that are insensitive to changes in the substrate characteristics are set based on the obtained relationship. In this way, it is possible to simultaneously measure the substrate position and detect the pattern quality with high accuracy.

[0081] <Fourth embodiment> As a fourth embodiment, a measurement method for detecting a measurement error (TIS) caused by a measurement device and a measurement error (WIS) caused by the characteristics of a pattern formed on a substrate will be described.

[0082] First, we will explain TIS and WIS. TIS is an error that occurs due to aberrations and other factors inherent in the measurement device, and is not dependent on the orientation of the substrate. On the other hand, WIS is a measurement error that results from the shape, structure, and physical properties of the pattern formed on the substrate, and therefore its sign changes depending on the orientation of the substrate. In order to align the substrate 73 with high precision and form a device pattern at the desired position, it is important to detect whether or not there is a change in TIS and WIS.

[0083] The measurement method in the fourth embodiment will be described below with reference to FIG. 13. The difference between the fourth embodiment and the first embodiment is that the position of the substrate is changed to acquire signal information of the pattern. This part will be described in detail. The other parts have the same configuration as the first embodiment, so their description will be omitted here. Items not mentioned here can follow the first embodiment.

[0084] Fig. 13 is a diagram showing a measurement sequence in the fourth embodiment. S1301 and S1303 to S1305 shown in Fig. 13 are the same as S501 and S503 to S1105 shown in Fig. 5, and therefore description thereof will be omitted here.

[0085] In S1302, the control unit 11 can cause the image sensor 75 (imaging unit) to acquire signal information of the measurement pattern 72 on the substrate 73 multiple times while varying at least one measurement parameter. The multiple measurements can include measurements at positions in the rotational direction of the substrate, for example, when the substrate is at 0° and 180° positions.

[0086] In S1306, signal information of measurement pattern 72 is acquired, at least one of TIS and WIS is removed, the difference from reference data is calculated, and whether the tolerance can be achieved is determined. The reference data may be characteristic information or position information of multiple substrates that has been calculated in advance. Furthermore, the tolerance may be set to the amount of variation among multiple substrates that has been calculated in advance, or the shape of the substrate required to achieve the overlay target.

[0087] The calculation method for detecting TIS and WIS in the fourth embodiment will be described below.

[0088] The substrate is rotated to positions of 0° and 180°, and the pattern position is found, resulting in measurement values ​​M0 and M180. Furthermore, the errors generated by the interaction between the positional deviation amount Shift during substrate transport and TIS and WIS are defined as TWI0 and TWI180. In this case, the measurement values ​​M0 and M180 are expressed by the following equations. M0=Shift+TIS+WIS+TWI0 (Equation 6) M180=-Shift+TIS-WIS+TWI180 (Equation 7)

[0089] If you want to detect TIS, you can perform calculations to remove WIS, so the measurement value MTIS when detecting TIS is expressed by the following equation. MTIS=Shift+TIS+(TWI0-TWI180) / 2 (Formula 8)

[0090] According to Equation 8, it is possible to detect TIS with higher accuracy than with Equations 6 and 7.

[0091] On the other hand, when WIS is to be detected, calculation processing can be performed to remove TIS, and the measurement value MWIS when detecting WIS is expressed by the following equation. MWIS=Shift+WIS+(TWI0-TWI180) / 2 (Formula 9)

[0092] According to Equation 9, it is possible to detect WIS with higher accuracy than with Equations 6 and 7.

[0093] As described above, in the fourth embodiment, the light from the pattern formed on the substrate is captured, the relationship between the measurement parameters and the signal information is obtained, and measurement processing conditions that are sensitive to changes in the characteristics of the substrate are set based on the obtained relationship. Furthermore, by arithmetically processing the signal information at different substrate positions, the TIS and WIS can be detected with high accuracy.

[0094] <Embodiments of a lithography apparatus including a measurement device> A lithography apparatus incorporating the above-described measurement device will be described below. The lithography apparatus is an apparatus that transfers a pattern onto a substrate, and can be, for example, an exposure apparatus, an imprint apparatus, or an electron beam lithography apparatus. FIG. 14 is a schematic diagram showing the configuration of an exposure apparatus EXA as an example of a lithography apparatus. The exposure apparatus EXA is used in a lithography process, which is a manufacturing process for articles or devices such as semiconductor elements or liquid crystal display elements, and forms a pattern on a substrate 83. The exposure apparatus EXA exposes the substrate 83 through a reticle 31, which is an original, and transfers the pattern of the reticle 31 onto the substrate 83. In this embodiment, the exposure apparatus EXA employs a step-and-scan method, but it is also possible to employ a step-and-repeat method or other exposure methods.

[0095] As shown in FIG. 14, the exposure apparatus EXA has an illumination optical system 801, a reticle stage RS that holds a reticle 31, a projection optical system 32, a substrate stage WS that holds a substrate 83, a position measurement device 550, and a control unit 1200.

[0096] The illumination optical system 801 is an optical system that illuminates an illuminated surface using light from the light source unit 800. The light source unit 800 includes, for example, a laser. The laser includes an ArF excimer laser with a wavelength of approximately 193 nm, a KrF excimer laser with a wavelength of approximately 248 nm, etc., but the type of light source is not limited to an excimer laser. For example, the light source unit 800 may use an F2 laser with a wavelength of approximately 157 nm or EUV (Extreme ultraviolet) with a wavelength of 20 nm or less as a light source.

[0097] In this embodiment, the illumination optical system 801 shapes the light from the light source unit 800 into a slit beam of light having a predetermined shape optimal for exposure, and illuminates the reticle 31. The illumination optical system 801 has the function of uniformly illuminating the reticle 31 and the function of polarized illumination. The illumination optical system 801 includes, for example, lenses, mirrors, an optical integrator, an aperture, etc., and is configured by arranging a condenser lens, a fly's-eye lens, an aperture aperture, a condenser lens, a slit, and an imaging optical system in this order.

[0098] The reticle 31 is made of, for example, quartz. On the reticle 31, a pattern (circuit pattern) to be transferred onto the substrate 83 is formed.

[0099] The reticle stage RS holds the reticle 31 via a reticle chuck (not shown) and is connected to a reticle drive mechanism (not shown). The reticle drive mechanism includes a linear motor and the like, and is able to move the reticle 31 held by the reticle stage RS by driving the reticle stage RS in the X-axis, Y-axis, and Z-axis directions and in the rotational directions about each axis. The position of the reticle 31 is measured by a reticle position measurement unit (not shown) of an oblique incidence system, and the reticle is positioned at a predetermined position via the reticle stage RS.

[0100] The projection optical system 32 has the function of forming an image of light from an object plane onto an image plane. In this embodiment, the projection optical system 32 projects light (diffracted light) that has passed through the pattern of the reticle 31 onto the substrate 83, forming an image of the pattern of the reticle 31 on the substrate. The projection optical system 32 may be an optical system made up of multiple lens elements, an optical system including multiple lens elements and at least one concave mirror (a catedioptric optical system), or an optical system including multiple lens elements and at least one diffractive optical element such as a kinoform.

[0101] A photoresist is applied to the substrate 83. The substrate 83 is an object to be processed onto which the pattern of the reticle 31 is transferred, and includes a wafer, a liquid crystal substrate, other substrates to be processed, and the like.

[0102] The substrate stage WS holds the substrate 83 via a substrate chuck (not shown) and is connected to a substrate driving mechanism (not shown). The substrate driving mechanism is a positioning mechanism that positions the substrate 83 based on the position of a mark measured using the position measurement device 550. The substrate driving mechanism includes a linear motor and the like, and can move the substrate 83 held by the substrate stage WS by driving the substrate stage WS in the X direction, Y direction, Z direction, and rotational directions around each axis. In addition, a reference plate 39 is provided on the substrate stage WS.

[0103] The positions of the reticle stage RS and the substrate stage WS are monitored by, for example, a six-axis laser interferometer 91, and under the control of the control unit 1200, the reticle stage RS and the substrate stage WS are driven at a constant speed ratio.

[0104] The control unit 1200 is configured as a computer (information processing device) including a CPU, memory, etc., and, for example, controls each unit of the exposure apparatus EXA in accordance with a program stored in a storage unit to operate the exposure apparatus EXA. The control unit 1200 controls the exposure process of exposing the substrate 83 via the reticle 31 and transferring the pattern of the reticle 31 onto the substrate 83. In this embodiment, the control unit 1200 also controls the measurement process in the position measurement device 550 and the correction process (arithmetic process) of the measurement values ​​obtained by the position measurement device 550. In this way, the control unit 1200 also functions as a part of the position measurement device 550.

[0105] In the exposure apparatus EXA, light (diffracted light) that has passed through the reticle 31 is projected onto the substrate 83 via the projection optical system 32. The reticle 31 and the substrate 83 are arranged in an optically conjugate relationship. The pattern of the reticle 31 is transferred onto the substrate 83 by scanning the reticle 31 and the substrate 83 at a speed ratio that is the reduction magnification ratio of the projection optical system 32.

[0106] The position measurement device 550 is a measurement device that measures the position of an object. In this embodiment, the position measurement device 550 measures the position of a mark 82 such as an alignment mark provided on a substrate 83. The wavelength tuning means 540 is composed of a wavelength tuning element and a holding member, and is driven in the X direction by a control unit using a driving mechanism (not shown).

[0107] 15, a description will be given of the sequence of the exposure process in which the substrate 83 is exposed through the reticle 31 and the pattern of the reticle 31 is transferred onto the substrate 83. As described above, the exposure process is performed by the control unit 1200 comprehensively controlling each unit of the exposure apparatus EXA.

[0108] In S101, the substrate 83 is loaded into the exposure apparatus EXA. In S102, a shape measurement device (not shown) detects the surface (height) of the substrate 83 and measures the surface shape of the entire area of ​​the substrate 83.

[0109] In S103, calibration is performed. Specifically, the substrate stage WS is driven so that the reference mark is positioned on the optical axis of the position measurement device 550 based on the design coordinate position of the reference mark provided on the reference plate 39 in the stage coordinate system. Next, the positional deviation of the reference mark relative to the optical axis of the position measurement device 550 is measured, and based on the positional deviation, the stage coordinate system is reset so that the origin of the stage coordinate system coincides with the optical axis of the position measurement device 550. Next, based on the design positional relationship between the optical axis of the position measurement device 550 and the optical axis of the projection optical system 32, the substrate stage WS is driven so that the reference mark is positioned on the optical axis of the exposure light. Then, the positional deviation of the reference mark relative to the optical axis of the exposure light is measured using a TTL (through-the-lens) measurement system via the projection optical system 32.

[0110] In S104, based on the result of the calibration in S103, a baseline is determined between the optical axis of the position measurement device 550 and the optical axis of the projection optical system 32. In S105, the position measurement device 550 measures the position of the mark 82 provided on the substrate 83.

[0111] In S106, global alignment is performed. Specifically, based on the measurement results in S105, the shift, magnification, and rotation are calculated for the arrangement of shot areas on substrate 83, and the regularity of the arrangement of shot areas is determined. Then, a correction coefficient is determined from the regularity of the arrangement of shot areas and the baseline, and substrate 83 is aligned with reticle 31 (exposure light) based on the correction coefficient.

[0112] In S107, the substrate 83 is exposed while scanning the reticle 31 and the substrate 83 in the scanning direction (Y direction). At this time, the substrate stage WS is driven in the Z direction and tilt direction based on the surface shape of the substrate 83 measured by the shape measurement device, and an operation is also performed to sequentially align the surface of the substrate 83 with the imaging plane of the projection optical system 32.

[0113] In S108, it is determined whether exposure of all shot areas on substrate 83 has been completed (i.e., whether there are any unexposed shot areas). If exposure of all shot areas on substrate 83 has not been completed, the process proceeds to S107, and S107 and S108 are repeated until exposure of all shot areas is completed. On the other hand, if exposure of all shot areas on substrate 83 has been completed, the process proceeds to S109, and substrate 83 is unloaded from exposure apparatus EXA.

[0114] In this embodiment, the position of the mark 82 is measured using a plurality of different measurement parameters, and the sensitivity of the measurement value to measurement parameter variations is calculated for at least two or more candidate measurement parameters. Then, the measurement parameters to be used in the measurement are determined based on the sensitivity. This reduces errors in alignment measurement, enabling high-precision alignment. Therefore, this embodiment can provide a position measurement device that can measure the position of a pattern on a substrate at high speed and with high precision.

[0115] <Embodiment of an article manufacturing method> An article manufacturing method for manufacturing an article using the above-described lithography apparatus will be described below as an example. The article manufacturing method is suitable for manufacturing articles such as devices (semiconductor elements, magnetic storage media, liquid crystal display elements, etc.). The manufacturing method includes a step of exposing a substrate coated with a photosensitive agent (forming a pattern on the substrate) using the exposure apparatus EXA, and a step of developing the exposed substrate (processing the substrate). The manufacturing method may also include other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.). The article manufacturing method of this embodiment is advantageous over conventional methods in at least one of article performance, quality, productivity, and production cost. The above-described article manufacturing method may also be performed using a lithography apparatus such as an imprinting apparatus or a drawing apparatus.

[0116] The disclosure of the present specification includes at least the following techniques. (Item 1) a preliminary measurement step of performing preliminary measurement a plurality of times while varying parameter values ​​of measurement parameters, the preliminary measurement being performed using measurement light to detect a plurality of targets formed on the substrate and obtain signal information; an acquisition step of obtaining a relationship between parameter values ​​and signal information based on the results of the preliminary measurements performed multiple times; a determination step of determining a target to be subjected to main measurement from among the plurality of targets based on the obtained relationship; a main measurement step of performing a main measurement on the determined target; A measuring method comprising: (Item 2) 2. The measurement method according to item 1, wherein the measurement parameters include at least one of a central wavelength, a wavelength width, a σ value, and polarization characteristics in an optical path of a measurement device that performs the preliminary measurement and the main measurement of the measurement light. (Item 3) 3. The measurement method according to item 2, wherein the signal information is at least one of contrast, signal intensity information, and position information of the plurality of targets. (Item 4) the plurality of targets is a pattern composed of a plurality of line elements, the measurement parameter is a central wavelength of the measurement light that illuminates the pattern, the signal information is a contrast of each of the plurality of line elements; In the obtaining step, a relationship between a center wavelength and a contrast is obtained for each of the plurality of line elements; In the determining step, a line element having a maximum contrast value that is less than a threshold value in the relationship among the plurality of line elements is excluded from the main measurement. 4. The measurement method according to item 3, (Item 5) the plurality of targets are patterns made up of a plurality of line elements, and are arranged in a plurality of predetermined shot areas on the substrate, each of which is set as a sample area candidate, the measurement parameter is a central wavelength of the measurement light that illuminates the pattern, the signal information is asymmetry of the measurement signal; In the acquiring step, a relationship between a center wavelength and asymmetry of a measurement signal is acquired for each of the predetermined plurality of shot areas; In the determining step, a shot area in which a minimum value of asymmetry in the relationship exceeds a threshold is excluded from the sample area candidates from among the predetermined plurality of shot areas. 3. The measurement method according to item 2, (Item 6) the target is a pattern made up of a plurality of line elements, the determining step includes calculating a weighting coefficient when the position of the pattern is expressed as a weighted average of the positions of the plurality of line elements; 4. The measurement method according to item 3, (Item 7) the target is a pattern made up of a plurality of line elements, the determining step includes setting a processing area for each of the plurality of line elements, and determining a weighting coefficient for each processing area based on overlay measurement values ​​for a plurality of shot areas of the substrate. 4. The measurement method according to item 3, (Item 8) 8. The measurement method according to any one of items 4 to 7, wherein the pattern made up of the plurality of line elements is a line and space pattern having spaces between adjacent line elements. (Item 9) 2. The measurement method according to item 1, wherein the measurement parameters include a position of the substrate in a rotational direction. (Item 10) 10. The measurement method according to item 9, wherein the main measurement step includes detecting at least one of a measurement error caused by a measurement device that performs the preliminary measurement and the main measurement and a measurement error caused by characteristics of a pattern formed on the substrate. (Item 11) measuring a position of a target on a substrate according to the measurement method of any one of items 1 to 10, and transferring a pattern onto the substrate based on the position of the target; processing the substrate to which the pattern has been transferred to obtain an article; A method for manufacturing an article, comprising: (Item 12) A measurement device comprising a measurement unit and a control unit, The control unit controlling the measurement unit so that preliminary measurement, which uses measurement light to detect a plurality of targets formed on a substrate and obtain signal information, is performed a plurality of times while varying parameter values ​​of measurement parameters; obtaining a relationship between a parameter value and signal information based on the results of the preliminary measurements performed multiple times; determining a target to be subjected to main measurement from among the plurality of targets based on the acquired relationship; controlling the measurement unit to perform a main measurement on the determined target; A measuring device characterized by: (Item 13) 1. A lithographic apparatus comprising: Item 13. The measurement device according to item 12, configured to measure the position of a mark provided on a substrate; a positioning mechanism that positions the substrate based on the position of the mark measured using the measurement device, A lithographic apparatus configured to transfer a pattern onto the substrate. (Item 14) Transferring a pattern onto a substrate using the lithography apparatus according to item 13; processing the substrate to which the pattern has been transferred to obtain an article; A method for manufacturing an article, comprising:

[0117] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0118] 11: control unit, 50: imaging unit, 100: measurement device, 72: measurement pattern, 73: substrate

Claims

1. a preliminary measurement step of performing preliminary measurement a plurality of times while varying parameter values ​​of measurement parameters, the preliminary measurement being performed using measurement light to detect a plurality of targets formed on the substrate and obtain signal information; an acquisition step of obtaining a relationship between parameter values ​​and signal information based on the results of the preliminary measurements performed multiple times; a determination step of determining a target to be subjected to main measurement from among the plurality of targets based on the obtained relationship; a main measurement step of performing a main measurement on the determined target; A measuring method comprising:

2. 2. The measurement method according to claim 1, wherein the measurement parameters include at least one of a central wavelength, a wavelength width, a σ value, and polarization characteristics in an optical path of a measurement device that performs the preliminary measurement and the main measurement of the measurement light.

3. 3. The measurement method according to claim 2, wherein the signal information is at least one of contrast, signal intensity information, and position information of the plurality of targets.

4. the plurality of targets is a pattern composed of a plurality of line elements, the measurement parameter is a central wavelength of the measurement light that illuminates the pattern, the signal information is a contrast of each of the plurality of line elements; In the obtaining step, a relationship between a center wavelength and a contrast is obtained for each of the plurality of line elements; In the determining step, a line element having a maximum contrast value that is less than a threshold value in the relationship among the plurality of line elements is excluded from the main measurement.

4. The measuring method according to claim 3.

5. the plurality of targets are patterns made up of a plurality of line elements, and are arranged in a plurality of predetermined shot areas on the substrate, each of which is set as a sample area candidate, the measurement parameter is a central wavelength of the measurement light that illuminates the pattern, the signal information is asymmetry of the measurement signal; In the acquiring step, a relationship between a center wavelength and asymmetry of a measurement signal is acquired for each of the predetermined plurality of shot areas; In the determining step, a shot area in which a minimum value of asymmetry in the relationship exceeds a threshold is excluded from the sample area candidates from among the predetermined plurality of shot areas.

3. The measuring method according to claim 2.

6. the target is a pattern made up of a plurality of line elements, the determining step includes calculating a weighting coefficient when the position of the pattern is expressed as a weighted average of the positions of the plurality of line elements; 4. The measuring method according to claim 3.

7. the target is a pattern made up of a plurality of line elements, the determining step includes setting a processing area for each of the plurality of line elements, and determining a weighting coefficient for each processing area based on overlay measurement values ​​for a plurality of shot areas of the substrate.

4. The measuring method according to claim 3.

8. 5. The measurement method according to claim 4, wherein the pattern made up of the plurality of line elements is a line and space pattern having a space between adjacent line elements.

9. 2. The measurement method according to claim 1, wherein the measurement parameters include a position of the substrate in a rotational direction.

10. 10. The measurement method according to claim 9, wherein the main measurement step includes detecting at least one of a measurement error caused by a measurement device that performs the preliminary measurement and the main measurement and a measurement error caused by characteristics of a pattern formed on the substrate.

11. a step of measuring a position of a target on a substrate according to the measurement method of claim 1 and transferring a pattern onto the substrate based on the position of the target; processing the substrate to which the pattern has been transferred to obtain an article; A method for manufacturing an article, comprising:

12. A measurement device comprising a measurement unit and a control unit, The control unit controlling the measurement unit so that preliminary measurement, which uses measurement light to detect a plurality of targets formed on a substrate and obtain signal information, is performed a plurality of times while varying parameter values ​​of measurement parameters; obtaining a relationship between a parameter value and signal information based on the results of the preliminary measurements performed multiple times; determining a target to be subjected to main measurement from among the plurality of targets based on the acquired relationship; controlling the measurement unit to perform a main measurement on the determined target; A measuring device characterized by:

13. 1. A lithographic apparatus comprising:

13. The measurement device according to claim 12, configured to measure the position of a mark provided on a substrate; a positioning mechanism that positions the substrate based on the position of the mark measured using the measurement device, A lithographic apparatus configured to transfer a pattern onto the substrate.

14. Transferring a pattern onto a substrate using a lithographic apparatus according to claim 13; processing the substrate to which the pattern has been transferred to obtain an article; A method for manufacturing an article, comprising:

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