Measuring device, measuring method, exposure method, exposure apparatus, and method for manufacturing articles

Abstract

This technology provides advantages for measuring the height position of a measurement area. [Solution] A measurement method is provided for measuring the height position of a measurement area by irradiating the measurement area with light and detecting the reflected light from the measurement area with a sensor, the method comprising: a first step of acquiring information on the distribution of reflectance within the measurement area; and a second step of setting a measurement target location within the measurement area in a region where the amount of reflected light detected by the sensor falls within a predetermined range, based on the information.

Description

Technical Field

[0001] The present invention relates to a measuring device, a measuring method, an exposure method, an exposure device, and a method for manufacturing an article.

Background Art

[0002] Conventionally, as a measuring device for measuring the surface position (height position) of a measurement object, a measuring device has been proposed that projects light from a light projecting unit onto the measurement object and detects the light (reflected light) reflected by the measurement object with a light receiving element to measure the surface position (see Patent Document 1). Patent Document 1 discloses a technique for adjusting the amount of light projected from the light projecting unit for each measurement location in order to enable highly accurate measurement of the surface position even when the reflectance varies depending on the material or pattern of the measurement object.

Prior Art Documents

[0006] To achieve the above objective, a measurement method as one aspect of the present invention is a measurement method for measuring the height position of a measurement area by irradiating a measurement area with light and detecting the reflected light from the measurement area with a sensor, characterized in that it comprises a first step of acquiring information on the distribution of reflectance within the measurement area, and a second step of setting a measurement target location in the measurement area within the measurement area in which the amount of reflected light detected by the sensor falls within a predetermined range, based on the information.

[0007] Further objects or other aspects of the present invention will be revealed by embodiments described below with reference to the accompanying drawings. [Effects of the Invention]

[0008] According to the present invention, for example, a technique advantageous for measuring the height position of a measurement area is provided. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing the configuration of an exposure apparatus as one aspect of the present invention. [Figure 2] This is a diagram illustrating the configuration of the measurement unit. [Figure 3] Figure 1 is a flowchart illustrating the measurement and exposure processes in the exposure apparatus shown. [Figure 4] This is a diagram illustrating the adjustment of the amount of reflected light. [Figure 5] This is a diagram to explain the setting of the measurement target. [Figure 6] This is a diagram to explain the setting of the measurement target. [Figure 7] Figure 1 is a flowchart illustrating the measurement and exposure processes in the exposure apparatus shown. [Figure 8] Figure 1 is a flowchart illustrating the measurement and exposure processes in the exposure apparatus shown. [Figure 9] This diagram illustrates the grouping of measurement targets. [Modes for carrying out the invention]

[0010] 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.

[0011] Figure 1 is a schematic diagram showing the configuration of an exposure apparatus 1 as one aspect of the present invention. The exposure apparatus 1 is a lithography apparatus used in the lithography process, which is a manufacturing process for articles (devices) such as semiconductor elements, liquid crystal display elements, and thin-film magnetic heads, to form a pattern on a substrate. The exposure apparatus 1 exposes the substrate through a master plate (reticle or mask) and transfers the pattern of the master plate to the substrate.

[0012] In this specification and the accompanying drawings, directions are indicated in an XYZ coordinate system where the direction parallel to the surface on which the substrate is placed is 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 axis, Y axis, and Z axis are defined as θX, θY, and θZ, respectively.

[0013] The exposure apparatus 1 includes an illumination optical system 102, a master plate stage (not shown) that can hold and move a master plate 103, a projection optical system 104, a substrate stage 105 that can hold and move a substrate ST, a measurement unit 106, and a control unit 107.

[0014] The light source 101 is composed of, for example, an i-line mercury lamp, an excimer laser, or the like. The illumination optical system 102 illuminates the reticle 103 with the light from the light source 101. A pattern to be projected onto the substrate ST is drawn on the reticle 103. The light that has passed through the reticle 103 reaches the substrate ST held by the substrate stage 105 via the projection optical system 104, and forms an image of the pattern on the reticle 103. The substrate stage 105 holds the substrate ST via a substrate chuck and is configured to be movable with respect to six axes including the X-axis, Y-axis, Z-axis, θZ-axis, θY-axis, and θZ-axis. The image of the pattern on the reticle 103 projected onto the substrate ST is transferred to a photosensitive material such as a resist pre-arranged (coated) on the surface of the substrate ST. By repeating the operation of stepwise moving the substrate stage 105 that holds the substrate ST and the operation of exposing the exposure area (shot area), an image of the pattern on the reticle 103 is transferred as a latent image to the photosensitive material arranged in each of the plurality of exposure areas on the substrate ST. The position and orientation of the substrate stage 105 are measured with high precision by a position measuring device (not shown) such as an interferometer or an encoder, and the movement and positioning of the substrate stage 105 (substrate 108) are controlled according to the measurement result. Thereby, highly accurate overlay exposure is realized.

[0015] When exposing the substrate ST, in order to match the height and tilt of the substrate ST with respect to the image of the pattern on the reticle 103 (image plane of the projection optical system 104), the height (height position) within the exposure area (measurement area) of the substrate ST is measured by the measurement unit 106. Then, based on the measurement result of the measurement unit 106, at least one of the height and tilt of the substrate stage 105 is controlled. Hereinafter, controlling at least one of the height and tilt of the substrate stage 105 so as to match the reference plane (for example, the surface or a plane offset from the surface) of the photosensitive material in the exposure area of the substrate ST with the image plane of the projection optical system 104 is referred to as focus control.

[0016] The measurement unit 106 is configured as a sensor that measures the height position of the exposure area by irradiating light onto the exposure area (measurement area) of the substrate ST and detecting the reflected light from the exposure area. In the present embodiment, the measurement unit 106 is embodied as a focus sensor of an oblique incidence method that irradiates light obliquely onto the exposure area of the substrate ST.

[0017] Referring to FIG. 2, the configuration of the measurement unit 106 will be specifically described. The measurement unit 106 measures the height positions of a plurality of measurement target locations within the exposure area of the substrate ST. The measurement unit 106 includes an irradiation unit 201 and a detection unit 205. The irradiation unit 201 includes a light source 202 that obliquely irradiates light onto the substrate ST held by the substrate stage 105, an irradiation pattern 203 arranged two-dimensionally, and an irradiation optical system 204 for irradiating (projecting) the irradiation pattern 203 onto the substrate ST. However, depending on the type of the light source 202 and the distance between the irradiation pattern 203 and the substrate ST, the irradiation optical system 204 may be omitted. Also, the irradiation optical system 204 may be used to establish a shine-proof optical system relationship between the irradiation pattern 203 and the substrate ST. By adopting a shine-proof optical system, it becomes possible to focus the entire area of the irradiation pattern 203 onto the substrate ST, so that the measurement accuracy can be improved. Also, the shine-proof optical system contributes to suppressing fluctuations in the measurement values due to local inclination of the substrate ST in the measurement of the height position of the substrate ST.

[0018] The detection unit 205 includes a detection optical system 207 and a camera 208. Light reflected from the substrate ST (reflected light) is incident on the camera 208 via the detection optical system 207. The camera 208 includes an image sensor 206 having a plurality of pixels arranged in two dimensions. However, depending on the type of light source 202 and the distance between the substrate ST and the camera 208, the detection optical system 207 may be omitted. Alternatively, the detection optical system 207 may be used to create a shine-proof optical system relationship between the substrate ST and the image sensor 206. By employing a shine-proof optical system, it becomes possible to focus the entire area of ​​the substrate ST onto the imaging surface of the image sensor 206. Furthermore, the shine-proof optical system contributes to suppressing fluctuations in measurement values ​​caused by local tilt of the substrate ST when measuring the height position of the substrate ST.

[0019] The control unit 107 is composed of an information processing device (computer) including a CPU and memory. The control unit 107 operates the exposure apparatus 1 by comprehensively controlling each part of the exposure apparatus 1, namely the light source 101, illumination optical system 102, projection optical system 104, measurement unit 106, and substrate stage 105, according to a program stored in the memory unit SU. For example, the control unit 107 controls the exposure process so that the entire substrate ST is exposed in a so-called step-and-repeat manner, by moving the substrate stage 105 in steps and repeatedly exposing each exposure area on the substrate.

[0020] In this embodiment, the control unit 107 also functions as a processing unit that controls the measurement unit 106 to determine the height position of the substrate ST (exposure area) (measurement processing). One such processing is determining the height position of the substrate ST from the change in the image (position) of the irradiation pattern 203 acquired by the image sensor 206. When the height of the substrate ST changes, the irradiation pattern 203 irradiated onto the substrate ST changes in the direction from the irradiation unit 201 to the substrate ST. Since such changes in the irradiation pattern 203 appear as a change in the image of the irradiation pattern 203 acquired by the image sensor 206, the height position of the substrate ST can be determined from this change. Based on the height of the substrate ST determined in this way, the control unit 107 exposes the substrate ST while adjusting the position of the substrate ST in the height direction (Z direction) via the substrate stage 105.

[0021] <First Embodiment> Referring to Figure 3, the measurement process and exposure process (exposure method) in the first embodiment will be described. In this embodiment, as described above, since the image sensor 206 has multiple pixels arranged in two dimensions, it is possible to measure the overall height position of the exposure area of ​​the substrate ST exposed in a step-and-repeat manner all at once at the same timing. However, it is difficult in terms of arrangement and cost to configure the irradiation unit 201 (light source 202, irradiation pattern 203, and irradiation optical system 204) individually for multiple measurement target locations within the exposure area of ​​the substrate ST. Therefore, in this embodiment, the light source 202 is configured as a single light source, and light from the single light source is irradiated onto the exposure area of ​​the substrate ST. Note that a single light source means a light source that irradiates light onto the entire exposure area of ​​the substrate ST all at once, and does not necessarily mean one light source. For example, an LED array may be used as the light source 202, or a light source that combines and irradiates light from two light source units may be used as the light source 202.

[0022] In S301, reflectance information regarding the reflectance distribution within the exposure area (measurement area) of the substrate ST is acquired. For example, a representative sample area among multiple exposure areas of the substrate ST is measured using the measurement unit 106, and the reflectance within the sample area is determined from the output of the measurement unit 106, thereby acquiring reflectance information for each exposure area of ​​the substrate ST.

[0023] In S302, based on the reflectance information acquired in S301, the amount of reflected light detected by the detection unit 205 is adjusted for each of the multiple locations (default locations) set as default measurement target locations within the exposure area of ​​the substrate ST. For example, the amount of light irradiated onto the exposure area of ​​the substrate ST, i.e., the amount of light irradiated from the irradiation unit 201 (light source 202), is adjusted so that the amount of reflected light from each default location falls within a predetermined range (detectable range).

[0024] Here, we will explain why S302 is necessary. The exposure area of ​​the substrate ST has various reflectivity at each location due to wiring, steps, material differences, etc. Therefore, in order to measure the height position of the exposure area of ​​the substrate ST with high precision, it is necessary to adjust the amount of light illuminating the exposure area of ​​the substrate ST so that the amount of reflected light detected by the image sensor 206 is within a certain range.

[0025] The adjustment of the reflected light intensity in S302 will be explained with reference to Figures 4(a) and 4(b). In Figure 4(a), 411 to 443 indicate the default measurement target locations (default locations) within the exposure area of ​​the substrate ST, and Figure 4(b) shows the amount of reflected light from each default measurement target location detected by the image sensor 206. As described above, the amount of reflected light from each measurement target location is adjusted to fall within a predetermined range by adjusting the amount of light emitted from the irradiation unit 201.

[0026] The predetermined range is determined to satisfy the required measurement accuracy based on the dynamic range and S / N characteristics of the image sensor 206. For example, if the amount of reflected light detected by the image sensor 206 is small, the measurement accuracy will decrease due to the effect of the S / N ratio, so it is necessary to incident a certain amount or more of reflected light onto the image sensor 206. On the other hand, if the amount of reflected light detected by the image sensor 206 is excessive, saturation will occur in the image sensor 206, and the measurement accuracy will decrease.

[0027] In this embodiment, since a single light source, i.e., one irradiation unit 201, is configured for multiple measurement target locations, it is necessary to adjust the amount of reflected light so that the signal-to-noise ratio (S / N ratio) is satisfied at all measurement target locations and saturation does not occur at the image sensor 206. First, the minimum amount of light irradiating the exposure area of ​​the substrate ST is determined from the reflectance at each measurement target location so that the S / N ratio of the reflected light amount satisfies a predetermined threshold. Next, it is confirmed that saturation does not occur at the image sensor 206 for all measurement target locations with this minimum amount of light.

[0028] In S303, it is determined whether the amount of reflected light for all default locations has been adjusted to fall within a predetermined range. If the amount of reflected light for all default locations cannot be adjusted to fall within a predetermined range, the process proceeds to S304. On the other hand, if the amount of reflected light for all default locations can be adjusted to fall within a predetermined range, the process proceeds to S305.

[0029] In S304, based on the reflectance information acquired in S301, the measurement target location is set (changed) to an area within the exposure region of the substrate ST in which the amount of reflected light detected by the detection unit 205 falls within a predetermined range. It is also possible to present the user with an area in which the amount of reflected light detected by the detection unit 205 falls within a predetermined range, or a candidate measurement target location, and set the measurement target location according to the user's instructions (selection).

[0030] Referring to Figures 5(a) and 5(b), the setting of the measurement target locations in S304 will be explained. For example, as shown in Figure 5(a), measurement target locations 411, 421, 431, and 441 are located on a wiring pattern 502 with high reflectivity. On the other hand, the reflectivity is lower at steps 501 such as scribe lines. In this case, measurement target locations 411, 421, 431, and 441, which are located on the wiring pattern 502, are shifted to measurement target locations 411', 421', 431', and 441', respectively, within a region where the amount of reflected light falls within a predetermined range. As a result, as shown in Figure 5(b), the amount of reflected light from measurement target locations 411', 421', 431', and 441' falls within a predetermined range, and approximately the same amount of reflected light as that from measurement target locations 413, 423, 433, and 443 is obtained.

[0031] As shown in Figure 5(a), steps 501 such as wiring patterns 502 and scribe lines generally exist parallel to the X and Y directions. Furthermore, the image sensor 206, which has multiple pixels arranged dimensionally, has a Region of Interest (ROI) function, and the image reading time is shortened depending on the area and number of columns to be read out. Therefore, as shown in Figure 5(a), it is preferable to shift (change) all of the measurement target locations 411 to 441 that are in the same column or row (on the same straight line parallel to the first direction) to a region where the amount of reflected light falls within a predetermined range (measurement target locations 411' to 441'). In this case, it is preferable to shift all of the measurement target locations 411 to 441 in the parallel direction (the second direction intersecting the first direction), and it is even more preferable to shift each of the measurement target locations 411 to 441 in the parallel direction by the same amount of shift. However, if the amount of reflected light falls within a predetermined range, measurement target locations 411 to 441 where the amount of reflected light falls outside the predetermined range may be individually shifted.

[0032] In S305, focus control is performed. Specifically, the measurement unit 106 measures the height position of the measurement target location (default measurement target location or measurement target location set in S304) within the exposure area of ​​the substrate ST. Based on the measurement result of the measurement unit 106, at least one of the height and tilt of the substrate stage 105 is controlled so that the exposure area of ​​the substrate ST coincides with the image plane of the projection optical system 104. In other words, the position of the substrate ST held by the substrate stage 105 in the height direction (Z direction) is adjusted.

[0033] In S306, the exposure area of ​​the substrate ST is exposed via the master plate 103. This transfers the pattern image of the master plate 103 to the exposure area (and the photosensitive material placed thereon) of the substrate ST.

[0034] Here, we consider the case where the amount of inclination of the exposed region of the substrate ST is determined from the measurement results (measured values) of multiple measurement targets within the exposure region of the substrate ST. For example, if the measured values ​​of two measurement targets are Data1 and Data2, and the distance between the two measurement targets is L, then the amount of inclination of the exposed region of the substrate ST is expressed by the following equation (1). Slope = (Data1 - Data2) / L ... (1) Referring to equation (1), it can be seen that if the distance L decreases by shifting (changing) the measurement target, the accuracy of the slope amount obtained from equation (1) decreases. Therefore, in order to avoid a decrease in the accuracy of the slope amount, the minimum required distance L is determined as follows.

[0035] Let A and B be the measurement reproducibility (standard deviation) of the measured values ​​Data1 and Data2, respectively, and define the reproducibility σ of the slope amount by the following equation (2). σ = SQRT(A 2 +B 2 ) / L ···(2) From equation (2), we can define the distance L as satisfying equation (3) below.

[0036] L≧SQRT(A 2 +B 2 ) / σm ···(3) Here, σm represents the measurement reproducibility of the slope amount that is acceptable for the measured values ​​Data1 and Data2.

[0037] Thus, in S304, it is preferable to set (change) the measurement targets so that the distance L between the measurement targets is greater than or equal to a predetermined distance, that is, so that equation (3) is satisfied.

[0038] In the explanation so far, we have described the case in which the measurement target location within the exposure area of ​​the substrate ST is set (shifted) from the perspective of the amount of reflected light detected by the detection unit 205. However, abrupt changes in reflectance can also be considered as a factor that affects measurement accuracy. Therefore, as shown in Figures 6(a) and 6(b), if the rate of change of the reflectance of the measurement target location exceeds a threshold, it is preferable to shift (change) that measurement target location. In this case, the rate of change of reflectance for each location within the exposure area of ​​the substrate ST relative to adjacent locations is determined from the reflectance information, and the measurement target location is set in the region where this rate of change is below the threshold.

[0039] For example, as shown in Figure 6(a), measurement targets 602 and 603 are located on a step 601 such as a circuit pattern. Figure 6(b) shows the reflectance distribution in the cross-section CA shown in Figure 6(a). Referring to Figure 6(b), although the reflectance itself is not significantly high or low at each of the measurement targets 602 and 603, the change in reflectance becomes steep due to the effect of the step 601. Therefore, measurement targets 602 and 603, where the rate of change in reflectance exceeds a threshold, are shifted to measurement targets 602' and 603', which are in the region where the rate of change in reflectance is below the threshold. This makes it possible to measure the height position of each measurement target in the exposure area of ​​the substrate ST with high precision.

[0040] Referring to Figure 7, the measurement and exposure processes will be described from the perspective of the rate of change of reflectance at each location within the exposure area of ​​the substrate ST relative to adjacent locations. In S701, similar to S301, reflectance information regarding the reflectance distribution within the exposure area (measurement area) of the substrate ST is acquired. In S702, the rate of change of reflectance at each location within the exposure area of ​​the substrate ST relative to adjacent locations is determined from the reflectance information acquired in S701. In S703, based on the rate of change of reflectance determined in S702, it is determined whether the rate of change of reflectance at each of the multiple locations (default locations) set as default measurement target locations within the exposure area of ​​the substrate ST exceeds a threshold. If the rate of change of reflectance at each of the multiple default locations exceeds the threshold, the process proceeds to S704. In S704, as explained with reference to Figures 6(a) and 6(b), the measurement target locations are set (changed) to areas within the exposure area of ​​the substrate ST where the rate of change of reflectance is below the threshold. Furthermore, when setting the measurement target locations, it is also possible to present the user with areas where the rate of change in reflectance is below a threshold, or candidate measurement target locations, and set the measurement target locations according to the user's instructions (selection). On the other hand, if the rate of change in reflectance of each of the multiple default locations is below the threshold, the process proceeds to S705. S705 and S706 are the same as S305 and S306, so a detailed explanation is omitted here.

[0041] In this embodiment, the measurement process and exposure process have been described with reference to Figures 3 and 8, respectively, from the viewpoint of the amount of reflected light detected by the detection unit 205 and the rate of change of reflectance at each location within the exposure area of ​​the substrate ST relative to adjacent locations. However, the measurement process and exposure process shown in Figure 3 and the measurement process and exposure process shown in Figure 8 can also be combined. For example, the measurement target locations may be set from the viewpoint of the amount of reflected light, and then the measurement target locations may be reset from the viewpoint of the rate of change of reflectance.

[0042] <Second Embodiment> Referring to Figure 8, the measurement process and exposure process in the second embodiment will be described. Note that S805 is the same as S306, so a detailed explanation will be omitted here.

[0043] In S801, similar to S301, reflectance information regarding the reflectance distribution within the exposure area (measurement area) of the substrate ST is acquired. In S802, based on the reflectance information acquired in S801, each of the multiple measurement target locations set as default in the exposure area of ​​the substrate ST is classified into one of several groups according to its reflectance (grouping of measurement target locations).

[0044] The grouping of measurement targets will be explained in detail with reference to Figures 9(a) and 9(b). For example, as shown in Figure 9(a), measurement target 911 is located on the wiring pattern 502, and measurement target targets 912 and 922 are located on the step 501. Measurement target targets 913, 921 and 923 are located in areas without the wiring pattern 502 or step 501. In this case, as shown in Figure 9(b), measurement target target 911 is classified into the first group, measurement target targets 912 and 922 into the second group, and measurement target targets 913, 921 and 923 into the third group, according to the reflectance within the exposure area of ​​the substrate ST.

[0045] In S803, for each of the multiple groups classified in S802, that is, for each group, the amount of light irradiated onto the exposure area of ​​the substrate ST is adjusted so that the amount of reflected light detected by the detection unit 205 of the measurement target location belonging to that group falls within a predetermined range.

[0046] In S804, focus control is performed. Specifically, for each group, i.e., in the order of the first group, second group, and third group, the exposure area of ​​the substrate ST is irradiated with the light intensity adjusted in S803, and the height position of the measurement target within the exposure area is measured by the measurement unit 106. Then, based on the measurement results of the measurement unit 106, at least one of the height and tilt of the substrate stage 105 is controlled so that the exposure area of ​​the substrate ST coincides with the image plane of the projection optical system 104.

[0047] The measurement and exposure processes in this embodiment are suitable, for example, when the reflectivity difference of the exposure area of ​​the substrate ST is large in a post-processing step, and it is difficult to obtain the required amount of reflected light at once with a single light source.

[0048] 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.

[0049] The method for manufacturing articles in the embodiments of the present invention is suitable for manufacturing articles such as flat panel displays, liquid crystal display elements, semiconductor elements, and MEMS. Such a manufacturing method includes the steps of exposing a substrate coated with a photosensitive agent using the exposure apparatus 1 (exposure method) described above, and developing the exposed photosensitive agent. Furthermore, an etching step or ion implantation step is performed on the substrate using the pattern of the developed photosensitive agent as a mask to form a circuit pattern on the substrate. These steps of exposure, development, etching, etc. are repeated to form a circuit pattern consisting of multiple layers on the substrate. In a subsequent step, dicing (processing) is performed on the substrate on which the circuit pattern has been formed, followed by chip mounting, bonding, and inspection steps. Such a manufacturing method may also include other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, resist peeling, etc.). The method for manufacturing articles in this embodiment is advantageous compared to conventional methods in at least one of the performance, quality, productivity, and production cost of the articles.

[0050] The disclosures herein include the following measuring devices, measuring methods, exposure methods, exposure apparatus, and methods for manufacturing articles.

[0051] (Item 1) A measurement method for measuring the height position of a measurement area by irradiating the measurement area with light and detecting the reflected light from the measurement area with a sensor, A first step is to acquire information regarding the distribution of reflectance within the measurement area, Based on the aforementioned information, a second step is to set the measurement target location within the measurement area in a region where the amount of reflected light detected by the sensor falls within a predetermined range. A measurement method characterized by having the following:

[0052] (Item 2) The measurement method according to item 1, characterized in that, in the second step, the measurement target locations are set by changing from a plurality of locations set as default measurement target locations within the measurement area, where the amount of reflected light detected by the sensor falls outside the predetermined range, to locations within the area where the amount of reflected light detected by the sensor falls within the predetermined range.

[0053] (Item 3) The aforementioned multiple locations include multiple first locations that lie on the same straight line parallel to the first direction, If any of the aforementioned first locations include a location where the amount of reflected light detected by the sensor falls outside the predetermined range, the second step involves changing all of the aforementioned first locations to locations within a region where the amount of reflected light detected by the sensor falls within the predetermined range. The measurement method described in item 2, characterized by the following:

[0054] (Item 4) The measurement method according to item 3, characterized in that, in the second step, all of the plurality of first locations are shifted in a second direction intersecting the first direction, thereby changing them to locations within a region in which the amount of reflected light detected by the sensor falls within a predetermined range.

[0055] (Item 5) The measurement method according to item 4, characterized in that in the second step, each of the plurality of first locations is shifted in the second direction by the same amount of shift.

[0056] (Item 6) The measurement method according to any one of items 2 to 5, characterized in that, in the second step, the measurement targets are set such that the distance between them is greater than or equal to a predetermined distance.

[0057] (Item 7) The method further includes a third step of adjusting the amount of light irradiated onto the measurement area so that the amount of reflected light detected by each of the sensors at the plurality of locations falls within the predetermined range, based on the aforementioned information. If, even after performing the third step, there is a location among the plurality of locations where the amount of reflected light detected by the sensor falls outside the predetermined range, then the second step is performed. A measurement method described in any one of items 2 to 6, characterized by the following:

[0058] (Item 8) After the second step, From the aforementioned information, the process involves determining the rate of change of reflectance at each location within the measurement area relative to adjacent locations, A step of resetting the measurement target location to a region where the rate of change is below a threshold, A measurement method according to any one of items 1 to 7, characterized by further comprising the following:

[0059] (Item 9) The measurement method according to any one of items 1 to 8, characterized in that the sensor is a focus sensor of the oblique incidence type that irradiates light obliquely onto the measurement area.

[0060] (Item 10) The measurement method according to any one of items 1 to 9, characterized in that the first step involves acquiring the information from the output of the sensor.

[0061] (Item 11) The measurement method according to any one of items 1 to 10, characterized in that the light irradiated onto the measurement area is light from a single light source.

[0062] (Item 12) A measurement method for measuring the height position of a measurement area by irradiating the measurement area with light and detecting the reflected light from the measurement area with a sensor, A step of acquiring information regarding the distribution of reflectance within the measurement area, From the aforementioned information, the process involves determining the rate of change of reflectance at each location within the measurement area relative to adjacent locations, Within the measurement area, the step of setting the measurement target location in the area where the rate of change is below a threshold, A measurement method characterized by having the following:

[0063] (Item 13) A measurement method for measuring the height position of a measurement area by irradiating the measurement area with light and detecting the reflected light from the measurement area with a sensor, A step of acquiring information regarding the distribution of reflectance within the measurement area, Based on the aforementioned information, the process involves classifying each of the multiple measurement target locations set as default within the measurement area into one of the multiple groups corresponding to the reflectance, A third step involves adjusting the amount of light irradiated onto the measurement area so that, for each of the aforementioned groups, the amount of reflected light detected by the sensor at the measurement target location belonging to that group falls within a predetermined range. A measurement method characterized by having the following:

[0064] (Item 14) A measuring device for measuring the height position of a measurement area, A measuring unit that irradiates the measurement area with light and detects the reflected light from the measurement area with a sensor to measure the height position of the measurement area, A control unit that controls the measurement unit, It has, The control unit, Information regarding the distribution of reflectance within the measurement area is obtained. Based on the above information, the measurement target location is set within the measurement area in a region where the amount of reflected light detected by the sensor falls within a predetermined range. A measuring device characterized by the following features.

[0065] (Item 15) An exposure method for exposing a substrate, The process involves irradiating the measurement area of ​​the substrate with light and detecting the reflected light from the measurement area with a sensor to measure the height position of the measurement area. A step of exposing the substrate while adjusting the height position of the substrate based on the aforementioned height position, It has, The step of measuring the height position is as follows: A step of acquiring information regarding the distribution of reflectance within the measurement area, Based on the aforementioned information, the step of setting the measurement target location within the measurement area in a region where the amount of reflected light detected by the sensor falls within a predetermined range, An exposure method characterized by including

[0066] (Item 16) An exposure apparatus for exposing a substrate, The measuring device described in item 14 for measuring the height position of the measurement area of ​​the substrate, A processing unit that exposes the substrate while adjusting the height position of the substrate based on the aforementioned height position, An exposure apparatus characterized by having the following.

[0067] (Item 17) A step of exposing the substrate using the exposure method described in item 15, A step of developing the exposed substrate, A process for manufacturing an article from the developed substrate, A method for manufacturing an article, characterized by having the following:

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

[0069] 1: Exposure apparatus 102: Illumination optical system 104: Projection optical system 105: Substrate stage 106: Measurement unit 107: Control unit 201: Irradiation unit 205: Detection unit ST: Substrate

Claims

1. A measurement method for measuring the height position of a measurement area by irradiating the measurement area with light and detecting the reflected light from the measurement area with a sensor, A first step is to acquire information regarding the distribution of reflectance within the measurement area, Based on the aforementioned information, a second step is to set the measurement target location within the measurement area in a region where the amount of reflected light detected by the sensor falls within a predetermined range. A measurement method characterized by having the following:

2. The measurement method according to claim 1, characterized in that, in the second step, the measurement target locations are set by changing from a plurality of locations set as default measurement target locations within the measurement area, where the amount of reflected light detected by the sensor falls outside the predetermined range, to locations within the area where the amount of reflected light detected by the sensor falls within the predetermined range.

3. The aforementioned multiple locations include multiple first locations that lie on the same straight line parallel to the first direction, If any of the aforementioned first locations include a location where the amount of reflected light detected by the sensor falls outside the predetermined range, the second step involves changing all of the aforementioned first locations to locations within a region where the amount of reflected light detected by the sensor falls within the predetermined range. The measurement method according to feature 2.

4. The measurement method according to claim 3, characterized in that, in the second step, all of the plurality of first locations are shifted in a second direction intersecting the first direction, thereby changing them to locations within a region in which the amount of reflected light detected by the sensor falls within a predetermined range.

5. The measurement method according to claim 4, characterized in that in the second step, each of the plurality of first locations is shifted in the second direction by the same amount of shift.

6. The measurement method according to claim 2, characterized in that, in the second step, the measurement targets are set such that the distance between them is greater than or equal to a predetermined distance.

7. The third step further includes adjusting the amount of light irradiated onto the measurement area so that the amount of reflected light detected by each of the sensors at the plurality of locations falls within the predetermined range, based on the aforementioned information. If, even after performing the third step, there is a location among the plurality of locations where the amount of reflected light detected by the sensor falls outside the predetermined range, then the second step is performed. The measurement method according to feature 2.

8. After the second step, From the aforementioned information, the process involves determining the rate of change of reflectance at each location within the measurement area relative to adjacent locations, A step of resetting the measurement target location to a region where the rate of change is below a threshold, The measurement method according to claim 1, further comprising the above.

9. The measurement method according to claim 1, characterized in that the sensor is a focus sensor of the oblique incidence type that irradiates light obliquely onto the measurement area.

10. The measurement method according to claim 1, characterized in that the first step involves acquiring the information from the output of the sensor.

11. The measurement method according to claim 1, characterized in that the light irradiated onto the measurement area is light from a single light source.

12. A measurement method for measuring the height position of a measurement area by irradiating the measurement area with light and detecting the reflected light from the measurement area with a sensor, A step of acquiring information regarding the distribution of reflectance within the measurement area, From the aforementioned information, the process involves determining the rate of change of reflectance at each location within the measurement area relative to adjacent locations, Within the measurement area, the step of setting the measurement target location in the area where the rate of change is below a threshold, A measurement method characterized by having the following:

13. A measurement method for measuring the height position of a measurement area by irradiating the measurement area with light and detecting the reflected light from the measurement area with a sensor, A step of acquiring information regarding the distribution of reflectance within the measurement area, Based on the aforementioned information, the process involves classifying each of the multiple measurement target locations set as default within the measurement area into one of the multiple groups corresponding to the reflectance, A third step involves adjusting the amount of light irradiated onto the measurement area so that, for each of the aforementioned multiple groups, the amount of reflected light detected by the sensor at the measurement target location belonging to that group falls within a predetermined range. A measurement method characterized by having the following:

14. A measuring device for measuring the height position of a measurement area, A measuring unit that irradiates the measurement area with light and detects the reflected light from the measurement area with a sensor to measure the height position of the measurement area, A control unit that controls the measurement unit, It has, The control unit, Information regarding the distribution of reflectance within the measurement area is obtained. Based on the above information, the measurement target location is set within the measurement area in a region where the amount of reflected light detected by the sensor falls within a predetermined range. A measuring device characterized by the following features.

15. An exposure method for exposing a substrate, The process involves irradiating the measurement area of ​​the substrate with light and detecting the reflected light from the measurement area with a sensor to measure the height position of the measurement area. A step of exposing the substrate while adjusting the height position of the substrate based on the aforementioned height position, It has, The step of measuring the height position is as follows: A step of acquiring information regarding the distribution of reflectance within the measurement area, Based on the aforementioned information, the step of setting the measurement target location within the measurement area in a region where the amount of reflected light detected by the sensor falls within a predetermined range, An exposure method characterized by including

16. An exposure apparatus for exposing a substrate, A measuring device according to claim 14 for measuring the height position of the measurement area of ​​the substrate, A processing unit that exposes the substrate while adjusting the height position of the substrate based on the aforementioned height position, An exposure apparatus characterized by having the following.

17. A step of exposing a substrate using the exposure method described in claim 15, A step of developing the exposed substrate, A process for manufacturing an article from the developed substrate, A method for manufacturing an article, characterized by having the following:

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