Measurement apparatus, measurement method, exposure method, exposure apparatus, and article manufacturing method

Abstract

The invention provides a measuring apparatus, a measuring method, an exposure method, an exposure apparatus, and an article manufacturing method. The measurement method measures a height position of a measurement region by irradiating the measurement region with light and detecting reflected light from the measurement region with a sensor, the measurement method including: obtaining information related to a reflectance distribution in the measurement region; and setting, on the basis of the information, a measurement target position in a region in which the amount of reflected light detected by the sensor falls within a predetermined range in the measurement region.

Description

Technical Field

[0001] This disclosure relates to measuring devices, measuring methods, exposure methods, exposure devices, and methods for manufacturing articles. Background Technology

[0002] Traditionally, Japanese Patent Application Publication No. 10-64980 discloses a measuring device for measuring the surface position (height position) of a target. This device measures the surface position by projecting light from a light-emitting unit onto the target and detecting the reflected light (reflected light) from the target using a light-receiving element. Japanese Patent Application Publication No. 10-64980 discloses a technique that adjusts the amount of light projected from the light-emitting unit for each measurement position, enabling accurate measurement of the surface position even when reflectivity changes due to the material, pattern, etc., of the target.

[0003] Traditional techniques utilize multiple light sources at each measurement location, allowing for measurements with appropriate light intensity for the target material or pattern, even within a single measurement. Furthermore, using a step-scan scheme and measuring each location simultaneously while scanning the target enables switching light intensity for each location. However, as the number of measurement locations increases, traditional techniques require additional light sources and light-receiving elements. This leads to increased cost and device size for the optical system. Summary of the Invention

[0004] This disclosure provides a technique that is advantageous in measuring the height position of a measurement area.

[0005] According to a first aspect of this disclosure, a measurement method is provided that measures the height position of a measurement area by illuminating the measurement area with light and detecting reflected light from the measurement area using a sensor, the measurement method comprising: obtaining information relating to the reflectivity distribution in the measurement area; and based on the information, setting a measurement target position in the measurement area in a region where the amount of reflected light detected by the sensor falls within a predetermined range.

[0006] According to a second aspect of this disclosure, a measurement method is provided that measures the height position of a measurement area by illuminating the measurement area with light and detecting reflected light from the measurement area using a sensor. The measurement method includes: obtaining information related to the reflectance distribution in the measurement area; obtaining from the information a rate of change of reflectance at locations adjacent to each location in the measurement area; and setting a measurement target location in the measurement area where the rate of change is not greater than a threshold.

[0007] According to a third aspect of this disclosure, a measurement method is provided that measures the height position of a measurement area by illuminating the measurement area with light and detecting reflected light from the measurement area using a sensor. The measurement method includes: obtaining information related to the reflectance distribution in the measurement area; classifying, based on the information, each of a plurality of measurement target positions set as default positions in the measurement area into any one of a plurality of groups corresponding to reflectance; and adjusting, for each of the plurality of groups, the amount of light used to illuminate the measurement area so that the amount of reflected light detected by the sensor at the measurement target position belonging to the group falls within a predetermined range.

[0008] According to a fourth aspect of this disclosure, a measuring apparatus is provided for measuring the height position of a measuring area, the measuring apparatus comprising: a measuring unit configured to measure the height position of the measuring area by illuminating the measuring area with light and detecting reflected light from the measuring area using a sensor; and a control unit configured to control the measuring unit, wherein the control unit obtains information relating to the reflectivity distribution in the measuring area, and based on the information, sets a measuring target position in the measuring area in an area where the amount of reflected light detected by the sensor falls within a predetermined range.

[0009] According to a fifth aspect of this disclosure, an exposure method for exposing a substrate to light is provided, the exposure method comprising: measuring the height position of a measurement area by illuminating a measurement area of ​​the substrate with light and detecting reflected light from the measurement area using a sensor; and exposing the substrate to light while adjusting the position of the substrate in a height direction based on the height position, wherein measuring the height position comprises: obtaining information related to a reflectivity distribution in the measurement area; and based on the information, setting a measurement target position in the measurement area in a region where the amount of reflected light detected by the sensor falls within a predetermined range.

[0010] According to a sixth aspect of this disclosure, an exposure apparatus is provided that exposes a substrate to light, the exposure apparatus comprising: the aforementioned measuring device configured to measure the height position of a measuring area of ​​the substrate; and a processing unit configured to expose the substrate to light while adjusting the position of the substrate in the height direction based on the height position.

[0011] According to a seventh aspect of this disclosure, a method for manufacturing an article is provided, comprising: exposing a substrate using the exposure method described above; developing the exposed substrate; and manufacturing an article from the developed substrate.

[0012] Other aspects of this disclosure will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0013] Figure 1 This is a schematic diagram illustrating the construction of an exposure apparatus according to one aspect of the present disclosure.

[0014] Figure 2 It is a diagram used to illustrate the construction of the measuring unit.

[0015] Figure 3 It is used for explanation Figure 1 The flowchart shows the measurement and exposure processes in the exposure apparatus.

[0016] Figure 4A and Figure 4B This is a diagram used to illustrate the adjustment of the amount of reflected light.

[0017] Figure 5A and Figure 5B It is a diagram used to illustrate the setup of the measurement target location.

[0018] Figure 6A and Figure 6B It is a diagram used to illustrate the setup of the measurement target location.

[0019] Figure 7 It is used for explanation Figure 1 The flowchart shows the measurement and exposure processes in the exposure apparatus.

[0020] Figure 8 It is used for explanation Figure 1 The flowchart shows the measurement and exposure processes in the exposure apparatus.

[0021] Figure 9A and Figure 9B It is a diagram used to illustrate the grouping of the locations of the measurement targets. Detailed Implementation

[0022] In the following, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments are not intended to limit the scope of the claims. Several features are described in the embodiments, but not all of such features are necessary, and multiple such features can be appropriately combined. Furthermore, in the drawings, the same or similar constructions are given the same reference numerals, and redundant descriptions thereof are omitted.

[0023] Figure 1This is a schematic diagram illustrating the construction of an exposure apparatus 1 according to one aspect of the present disclosure. The exposure apparatus 1 is, for example, a photolithography apparatus used in the photolithography step, which is a manufacturing step of articles (equipment) 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 to light through a raw plate (intermediate mask or mask) and transfers the pattern of the raw plate to the substrate.

[0024] In the specification and accompanying drawings, directions will be indicated in the XYZ coordinate system, in which the direction parallel to the plane on which the substrate is placed is defined as the XY plane. The directions parallel to the X-axis, Y-axis, and Z-axis of the XYZ coordinate system are the X direction, Y direction, and Z direction, respectively. Rotations about the X-axis, Y-axis, and Z-axis are θX, θY, and θZ, respectively.

[0025] The exposure apparatus 1 includes an illumination optical system 102, a raw plate stage (not shown) capable of holding the raw plate 103, a projection optical system 104, a substrate stage 105 capable of holding the substrate ST, a measurement unit 106, and a control unit 107.

[0026] Light source 101 is implemented, for example, an i-line mercury lamp or an excimer lamp. Illumination optics system 102 illuminates the original plate 103 with light from light source 101. A pattern to be projected onto substrate ST is drawn on the original plate 103. Light passing through the original plate 103 reaches the substrate ST held by substrate stage 105 via projection optics system 104 to form an image of the pattern on the original plate 103. Substrate stage 105 holds substrate ST by substrate chuck and is configured to be movable relative to six axes including the X-axis, Y-axis, Z-axis, θX-axis, θY-axis, and θZ-axis. The image of the pattern on the original plate 103 projected onto substrate ST is transferred onto a photosensitive material such as a resist placed (applied) on the surface of substrate ST. By repeatedly moving substrate stage 105 holding substrate ST and exposing the exposure area (image area) to light, the image of the pattern on the original plate 103 is transferred as a latent image onto photosensitive materials placed in various of the multiple exposure areas of substrate ST. A position measurement device, such as an interferometer or encoder (not shown), precisely measures the position and orientation of the substrate stage 105. Based on the measurement results, the movement and positioning of the substrate stage 105 (substrate ST) are controlled. This enables precise overlapping exposure.

[0027] When the substrate ST is exposed to light, in order to match the height and tilt of the substrate ST with the image of the pattern of the original board 103 (the imaging plane of the projection optics system 104), the measurement unit 106 measures the height (height position) of the substrate ST in the exposure area (measurement area). Based on the measurement results obtained by the measurement unit 106, at least the height or tilt of the substrate stage 105 is controlled. In the following description, controlling at least the height or tilt of the substrate stage 105 so that the reference surface of the photosensitive material in the exposure area of ​​the substrate ST (e.g., the front side or a surface offset from the front side) matches the imaging plane of the projection optics system 104 is referred to as focus control.

[0028] The measurement unit 106 is configured as a sensor that measures the height position of the exposure area by illuminating the exposure area (measurement area) of the substrate ST with light and detecting the reflected light from the exposure area. In this embodiment, the measurement unit 106 is implemented as an oblique incidence focusing sensor that obliquely illuminates the exposure area of ​​the substrate ST with light.

[0029] Reference Figure 2 The structure of the measurement unit 106 is described in detail below. The measurement unit 106 measures the height positions of multiple target locations in the exposure area of ​​the substrate ST. The measurement unit 106 includes an illumination unit 201 and a detection unit 205. The illumination unit 201 includes a light source 202 that applies light obliquely to the substrate ST held by the substrate stage 105, a two-dimensionally arranged illumination pattern 203, and an illumination optical system 204 for illuminating the substrate ST with the illumination pattern 203 (emitting light onto the substrate ST). Depending on the type of light source 202 or the distance between the illumination pattern 203 and the substrate ST, the illumination optical system 204 may be omitted. Alternatively, the illumination pattern 203 and the substrate ST may be arranged to implement a Scheimpflug optical system using the illumination optical system 104. Using a Scheimpflug optical system allows the entire area of ​​the illumination pattern 203 to be focused on the substrate ST, thereby improving measurement accuracy. In addition, the Scheimpflug optical system helps suppress measurement value variations caused by local tilting of the substrate ST when measuring the height position of the substrate ST.

[0030] The detection unit 205 includes a detection optics system 207 and a camera 208. Light reflected from the substrate ST (reflected light) enters the camera 208 through the detection optics system 207. The camera 208 includes an image sensor 206 with a plurality of pixels arranged in a two-dimensional manner. However, note that depending on the type of light source 202 or the distance between the substrate ST and the camera 208, the detection optics system 207 may be omitted. Alternatively, the substrate ST and the image sensor 206 may be arranged to implement a Scheimpflug optics system using the detection optics system 207. Employing a Scheimpflug optics system allows the entire area of ​​the substrate ST to be focused onto the imaging plane of the image sensor 206. Furthermore, the Scheimpflug optics system helps suppress measurement variations caused by local tilting of the substrate ST when measuring its height position.

[0031] The control unit 107 is implemented by an information processing device (computer) including a CPU and memory. The control unit 107 operates the exposure apparatus 1 by comprehensively controlling the various units of the exposure apparatus 1 (i.e., the light source 101, the illumination optical system 102, the projection optical system 104, the measurement unit 106, and the substrate stage 105) according to a program stored in the storage unit. The control unit 107 controls, for example, the exposure process to expose the entire area of ​​the substrate ST to light through a so-called step-repetition scheme, which repeatedly exposes individual exposure areas on the substrate while gradually moving the substrate stage 105.

[0032] The control unit 107 also functions as a processing unit that controls the measurement unit 106 to perform a process (measurement processing) to obtain the height position (exposure area) of the substrate ST. One such process is to obtain the height position of the substrate ST based on a change in the image (position) of the illumination pattern 203 obtained by the image sensor 206. As the height of the substrate ST changes, the illumination pattern 203 used to illuminate the substrate ST changes in the direction from the illumination unit 201 illuminating the substrate ST with the illumination pattern 203. Since this change in the illumination pattern 203 manifests as a change in the image of the illumination pattern 203 obtained by the image sensor 206, the height position of the substrate ST is obtained based on this change. The control unit 107 exposes the substrate ST to light while adjusting the position of the substrate ST in the height direction (Z direction) via the substrate stage 105 based on the height of the substrate ST obtained in this way.

[0033] <First Embodiment>

[0034] Reference Figure 3The measurement and exposure processes (exposure method) according to the first embodiment are described. As described above, since this embodiment provides an image sensor 206 with multiple pixels arranged in a two-dimensional manner, it is possible to measure the height position of the entire exposure area of ​​the substrate ST exposed to light by a step-repeating scheme at the same time. However, it should be noted that it is difficult to implement the illumination unit 201 (light source 202, illumination pattern 203, and illumination optics system 204) separately for multiple measurement target positions in the exposure area of ​​the substrate ST in terms of placement and cost. Therefore, in this embodiment, the light source 202 is implemented by a single light source, and the exposure area of ​​the substrate ST is illuminated with light from the single light source. Note that a single light source refers to a light source that applies light to the entire exposure area of ​​the substrate ST together, but it does not always refer to a single light source. For example, an LED array can be used as the light source 202, or as a light source that combines beams from two light source units and emits combined light.

[0035] In step S301, reflectance information related to the reflectance distribution in the exposed areas (measurement areas) of the substrate ST is obtained. For example, by measuring a representative sample area among multiple exposed areas of the substrate ST using the measurement unit 106, and obtaining the reflectance in the sample area from the output of the measurement unit 106, reflectance information related to each exposed area of ​​the substrate ST is obtained.

[0036] In step S302, based on the reflectivity information obtained in step S301, the amount of reflected light detected by the detection unit 205 is adjusted for each of the multiple positions (default positions) in the exposure area of ​​the substrate ST that are set as the measurement target positions. For example, the amount of light used to irradiate the exposure area of ​​the substrate ST (i.e., the amount of light emitted from the irradiation unit 201 (light source 202)) is adjusted so that the amount of reflected light from each default position falls within a predetermined range (detection allowable range).

[0037] The reason for step S302 will be described below. Due to wiring, stepped positions, material differences, etc., the exposure area of ​​the substrate ST has various reflectivities at different locations. Therefore, in order to accurately measure the height position of the exposure area of ​​the substrate ST, it is necessary to adjust the amount of light used to illuminate the exposure area of ​​the substrate ST so that the amount of reflected light detected by the image sensor 206 falls within a predetermined range.

[0038] Reference Figure 4A and Figure 4B Describe the adjustment of the reflected light amount in step S302. (Refer to...) Figure 4A Reference numerals 411 to 443 indicate the default measurement target position (default position) in the exposure area of ​​the substrate ST. Figure 4BThe image sensor 206 displays the amount of reflected light from each default measurement target location. As described above, by adjusting the amount of light emitted from the illumination unit 201, the amount of reflected light from each measurement target location is adjusted to fall within a predetermined range.

[0039] Based on the dynamic range and signal-to-noise ratio (S / N) characteristics of the image sensor 206, a predetermined range is determined to meet the necessary requirements for measurement accuracy. For example, if the amount of reflected light detected by the image sensor 206 is small, the measurement accuracy decreases due to the influence of the S / N ratio, thus requiring the application of a predetermined amount or more of reflected light to the image sensor 206. On the other hand, if the amount of reflected light detected by the image sensor 206 is too large, the image sensor 206 saturates, leading to a deterioration in measurement accuracy.

[0040] In this embodiment, since a single light source (i.e., one illumination unit 201) is placed for multiple measurement target locations, it is necessary to adjust the amount of reflected light to meet the S / N requirement at all measurement target locations and suppress saturation of the image sensor 206. First, based on the reflectivity at each measurement target location, the minimum amount of light used to illuminate the exposure area of ​​the substrate ST is obtained so that the S / N ratio of the reflected light meets a predetermined threshold. This minimum amount of light confirms that the image sensor 206 is not saturated at any measurement target location.

[0041] In step S303, it is determined whether the amount of reflected light can be adjusted to fall within a predetermined range for each default position. If the amount of reflected light cannot be adjusted to fall within the predetermined range for each default position, the process proceeds to step S304. Conversely, if the amount of reflected light can be adjusted to fall within the predetermined range for each default position, the process proceeds to step S305.

[0042] In step S304, based on the reflectivity information obtained in step S301, a measurement target position is set (changed) in the exposure area of ​​the substrate ST in an area where the amount of reflected light detected by the detection unit 205 falls within a predetermined range. Note that when setting the measurement target position, the measurement target position can also be set by presenting the area where the amount of reflected light detected by the detection unit 205 falls within the predetermined range or the measurement target position as candidates to the user, and following the user's instructions (selection).

[0043] Reference Figure 5A and Figure 5B Describe the settings for the measurement target position in step S304. For example, such as... Figure 5AAs shown, measurement target positions 411, 421, 431, and 441 exist on a wiring pattern 502 with high reflectivity. On the other hand, reflectivity decreases at stepped positions 501, such as scribbled lines. In this case, measurement target positions 411, 421, 431, and 441 on the wiring pattern 502 are respectively shifted to measurement target positions 411', 421', 431', and 441' in areas where the reflected light amount falls within a predetermined range. Figure 5B As shown, this allows the amount of reflected light from the measurement target positions 411', 421', 431' and 441' to fall within a predetermined range, so that approximately the same amount of reflected light can be obtained from the measurement target positions 413, 423, 433 and 443.

[0044] like Figure 5A As shown, generally, the wiring pattern 502 and the stepped positions 501 (such as scribing) are usually parallel to the X or Y direction. The image sensor 206, with multiple pixels arranged in a two-dimensional manner, has a region of interest (ROI) function, thereby reducing image reading time depending on the reading area or number of columns. Therefore, as... Figure 5A As shown, all measurement target positions 411 to 441 existing in the same column or row (existing on the same straight line parallel to the first direction) are preferably shifted (changed) to an area where the amount of reflected light falls within a predetermined range (measurement target positions 411' to 441'). In this case, all measurement target positions 411 to 441 are preferably shifted in a parallel direction (a second direction intersecting the first direction), and more preferably shifted in the parallel direction by the same amount as the shift of measurement target positions 411 to 441. However, note that any one of the measurement target positions 411 to 441 whose reflected light falls outside the predetermined range can be shifted individually within the area where the reflected light falls within the predetermined range.

[0045] In step S305, focus control is performed. More specifically, the measurement unit 106 measures the height of the target position (default target position or target position set in step S304) within the exposure area of ​​the substrate ST. Based on the measurement results obtained by the measurement unit 106, at least the height or tilt of the substrate stage 105 is controlled to match the exposure area of ​​the substrate ST with the imaging plane of the projection optical system 104. In other words, the position of the substrate ST in the height direction (Z direction) held by the substrate stage 105 is adjusted.

[0046] In step S306, the exposure area of ​​the substrate ST is exposed to light through the original plate 103. Through this operation, the image of the pattern on the original plate 103 is transferred onto the exposure area of ​​the substrate ST (on which the photosensitive material is placed).

[0047] This section considers the case where the tilt of the exposure area of ​​the substrate ST is obtained from measurement results (measured values) at multiple measurement target locations within the exposure area of ​​the substrate ST. Assuming the measured values ​​at two measurement target locations are represented by Data1 and Data2, respectively, and the distance between the two measurement target locations is represented by L, the tilt of the exposure area of ​​the substrate ST is expressed by the following equation (1):

[0048] Inclination amount = (Data1 - Data2) / L (1)

[0049] Referring to equation (1), as the distance L decreases with the displacement (change) of the measurement target position, the accuracy of the tilt amount obtained from equation (1) decreases. Therefore, in order to prevent the decrease in the accuracy of the tilt amount, the minimum value of the required distance L is determined as follows.

[0050] Let the measurement reproducibility (standard deviation) of measured values ​​Data1 and Data2 be A and B, respectively, and the reproducibility σ of the tilt amount be defined by the following equation (2):

[0051] σ = SQRT(A) 2 + B 2 ) / L (2)

[0052] The distance L that satisfies the following inequality (3) can be obtained from equation (2):

[0053] L ≥ SQRT(A 2 + B 2 ) / σm (3)

[0054] Wherein, σm is the measurement reproducibility of the allowable tilt amount for each measurement value Data1 and Data2.

[0055] As described above, in step S304, it is preferable to set (change) the measurement target position so that the distance L between the measurement target positions becomes a predetermined distance or greater, that is, to satisfy inequality (3).

[0056] So far, the case of setting (shifting) the measurement target position in the exposure area of ​​the substrate ST taking into account the amount of reflected light detected by the detection unit 205 has been described. However, drastic changes in reflectivity can be a factor affecting measurement accuracy. Therefore, as... Figure 6A and Figure 6B As shown, if the rate of change of reflectance at the target measurement location exceeds a threshold, the target measurement location is preferably shifted (changed). In this case, the rate of change of reflectance with respect to locations adjacent to each location in the exposure area of ​​the substrate ST is obtained based on reflectance information, and the target measurement location is set in the region where the rate of change is equal to or less than the threshold.

[0057] For example, such as Figure 6A As shown, the measurement target positions 602 and 603 are preset on a stepped position 601, such as a circuit pattern. Figure 6B Show Figure 6A The reflectivity distribution on section CA is shown. (Refer to...) Figure 6B Although the reflectivity at each measurement target location 602 and 603 is neither excessively high nor low, the reflectivity changes drastically due to the step-like position 601. Therefore, measurement target locations 602 and 603 where the rate of reflectivity change exceeds a threshold are shifted to measurement target regions 602' and 603' within regions where the rate of reflectivity change is equal to or less than the threshold. This allows for precise measurement of the height of each measurement target location within the exposure area of ​​the substrate ST.

[0058] Reference Figure 7 This describes a measurement and exposure process performed from the perspective of the rate of reflection change at locations adjacent to each position in the exposure area of ​​the substrate ST. In step S701, as in step S301, reflectance information related to the reflectance distribution in the exposure area (measurement area) of the substrate ST is obtained. In step S702, based on the reflectance information obtained in step S701, the rate of reflection change at locations adjacent to each position in the exposure area of ​​the substrate ST is obtained. In step S703, based on the rate of reflection change obtained in step S702, it is determined whether the rate of reflection change at each of the multiple locations (default locations) in the exposure area of ​​the substrate ST that are set as default measurement target locations exceeds a threshold. If the rate of reflection change at each of the multiple default locations exceeds the threshold, the process proceeds to step S704. In step S704, as referred to... Figure 6A and Figure 6B The measurement target position is set (changed) in the region of the exposure area of ​​the substrate ST where the rate of change of reflectance is equal to or less than a threshold. Alternatively, regions or measurement target positions where the rate of change of reflectance is equal to or less than the threshold can be presented to the user as candidates, and the measurement target position is set according to user instructions (selection). Conversely, if the rate of change of reflectance is equal to or less than the threshold at multiple default positions, the process proceeds to step S705. Since steps S705 and S706 are the same as steps S305 and S306, a detailed description of them will be omitted.

[0059] This embodiment refers to the amount of reflected light detected by the detection unit 205 and the rate of change of reflectance with respect to each position adjacent to the exposure area of ​​the substrate ST. Figure 3 and Figure 7 Examples of measurement and exposure processing are given. However, note that... Figure 3 The measurement processing and exposure processing shown are... Figure 7The measurement and exposure processes shown can be combined with each other. For example, after setting the target position from the perspective of the amount of reflected light, the target position can be set again from the perspective of the rate of change of reflectance.

[0060] <Second Embodiment>

[0061] Reference Figure 8 The measurement and exposure processes according to the second embodiment are described. Since step S805 is the same as step S306, its detailed description will be omitted.

[0062] In step S801, as in step S301, reflectance information related to the reflectance distribution in the exposure area (measurement area) of the substrate ST is obtained. In step S802, based on the reflectance information obtained in step S801, the multiple measurement target positions set to default positions in the exposure area of ​​the substrate ST are classified into multiple groups corresponding to reflectance (grouping the measurement target positions).

[0063] Reference Figure 9A and Figure 9B Describe in detail the grouping of the target locations. For example, such as... Figure 9A As shown, measurement target position 911 exists on wiring pattern 502, and measurement target positions 912 and 922 exist on stepped position 501. Note that measurement target positions 913, 921, and 923 exist in areas without wiring pattern 502 and stepped position 501. In this case, as... Figure 9B As shown, based on the reflectivity in the exposure area of ​​the substrate ST, the measurement target position 911 is classified into the first group, the measurement target positions 912 and 922 are classified into the second group, and the measurement target positions 913, 921 and 923 are classified into the third group.

[0064] In step S803, the amount of light used to irradiate the exposure area of ​​the substrate ST is adjusted so that the amount of reflected light detected by the detection unit 205 at the measurement target position of each of the multiple groups classified in step S802 (i.e., each group) falls within a predetermined range.

[0065] In step S804, focus control is performed. More specifically, while illuminating the exposure area of ​​the substrate ST with the light intensity adjusted in step S803 for each group (i.e., in the order of the first group, the second group, and the third group), the measurement unit 106 calculates the height position of the measurement target location in the exposure area. Based on the measurement results obtained by the measurement unit 106, at least the height or tilt of the substrate stage 105 is controlled to match the exposure area of ​​the substrate ST with the imaging plane of the projection optics system 104.

[0066] The measurement and exposure processing according to this embodiment is applicable to situations where the reflectivity of the exposed areas of the substrate ST varies greatly in subsequent steps, and it is difficult to obtain the required amount of reflected light using a single light source at once.

[0067] The method for manufacturing articles according to embodiments of this disclosure is applicable to the manufacture of articles such as flat panel displays, liquid crystal display elements, semiconductor devices, MEMS, etc. The manufacturing method includes the steps of exposing a substrate coated with a photosensitive agent using the aforementioned exposure apparatus 1 (exposure method) and developing the exposed photosensitive agent. An etching step and an ion implantation step are performed on the substrate using the pattern of the developed photosensitive agent as a mask to form a circuit pattern on the substrate. By repeating steps such as these exposure, development, and etching steps, a circuit pattern formed by multiple layers is formed on the substrate. In subsequent steps, the substrate with the formed circuit pattern is cut (processed), and chip mounting, bonding, and inspection steps are performed. The manufacturing method can also include other known steps (oxidation, deposition, vapor deposition, doping, planarization, resist removal, etc.). The method for manufacturing articles according to this embodiment is superior to conventional methods in at least one aspect of article performance, quality, productivity, and production cost.

[0068] While this disclosure has been described with reference to exemplary embodiments, it should be understood that this disclosure is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be given the broadest possible description to cover all such modifications and equivalent structures and functions.

Claims

1. A measurement method comprising measuring the height position of a measurement area by illuminating the measurement area with light and detecting reflected light from the measurement area using a sensor, the measurement method comprising: The step involves obtaining information related to the reflectance distribution in the measurement area; as well as The setup step involves, based on the information, setting a measurement target location within the measurement area where the amount of reflected light detected by the sensor falls within a predetermined range.

2. The measurement method according to claim 1, wherein, In the setting step, the measurement target position is set by changing one of the multiple positions in the measurement area where the amount of reflected light detected by the sensor falls outside the predetermined range to a position where the amount of reflected light detected by the sensor falls within the predetermined range.

3. The measurement method according to claim 2, wherein, The plurality of positions includes a plurality of first positions existing on the same straight line parallel to the first direction, and If the plurality of first positions include a position where the amount of reflected light detected by the sensor falls outside the predetermined range, in the setting step, all of the plurality of first positions are changed to a position where the amount of reflected light detected by the sensor falls within the predetermined range.

4. The measurement method according to claim 3, wherein, In the setting step, all of the plurality of first positions are shifted to positions within a predetermined range by being shifted in a second direction intersecting the first direction, such that the amount of reflected light detected by the sensor falls within that range.

5. The measurement method according to claim 4, wherein, In the setting step, each of the plurality of first positions is shifted by the same amount in the second direction.

6. The measurement method according to claim 2, wherein, In the setting step, the measurement target positions are set such that the distance between the measurement target positions is not less than a predetermined distance.

7. The measurement method according to claim 2, further comprising an adjustment step, based on the information, adjusting the amount of light used to illuminate the measurement area so that the amount of reflected light detected by the sensors at each of the plurality of locations falls within the predetermined range. in, The setting step is performed at the multiple locations, including those where the amount of reflected light detected by the sensor falls outside the predetermined range even after the adjustment step.

8. The measurement method according to claim 1, further comprising, after the setting step: The step involves obtaining, from the information, the rate of change of reflectance at locations adjacent to each location in the measurement area; as well as The reset step involves resetting the measurement target position in the region where the rate of change is no greater than a threshold.

9. The measurement method according to claim 1, wherein, The sensor is an oblique incidence focusing sensor, which is configured to illuminate the measurement area at an oblique angle.

10. The measurement method according to claim 1, wherein, In the obtaining step, information output from the sensor is obtained.

11. The measurement method according to claim 1, wherein, The light used to illuminate the measurement area is light from a single light source.

12. A measurement method comprising measuring the height position of a measurement area by illuminating the measurement area with light and detecting reflected light from the measurement area using a sensor, the measurement method comprising: To obtain information related to the reflectance distribution in the measurement area; The rate of change of reflectance at locations adjacent to each location in the measurement area is obtained from the information. as well as Within the measurement area, the measurement target location is set in the area where the rate of change is not greater than a threshold.

13. A measurement method comprising measuring the height position of a measurement area by illuminating the measurement area with light and detecting reflected light from the measurement area using a sensor, the measurement method comprising: To obtain information related to the reflectance distribution in the measurement area; Based on the information, each of the multiple measurement target locations that are set as default locations in the measurement area is classified into any one of multiple groups corresponding to reflectivity; as well as For each of the plurality of groups, the amount of light used to illuminate the measurement area is adjusted so that the amount of reflected light detected by the sensor at the measurement target location belonging to the group falls within a predetermined range.

14. A measuring device for measuring the height position of a measuring area, the measuring device comprising: A measurement unit is configured to measure the height position of the measurement area by illuminating the measurement area with light and detecting the reflected light from the measurement area using a sensor. as well as A control unit, configured to control the measuring unit. The control unit obtains information related to the reflectivity distribution in the measurement area, and based on the information, sets a measurement target position in the measurement area where the amount of reflected light detected by the sensor falls within a predetermined range.

15. An exposure method for exposing a substrate to light, the exposure method comprising: The height position of the measurement area is measured by illuminating the measurement area of ​​the substrate with light and detecting the reflected light from the measurement area using a sensor. as well as The substrate is exposed to light, and its position in the height direction is adjusted based on the height position. The measurement of the height position includes: Obtain information relating to the reflectance distribution in the measurement area; and Based on the information, in the measurement area, a measurement target position is set in an area where the amount of reflected light detected by the sensor falls within a predetermined range.

16. An exposure apparatus for exposing a substrate to light, the exposure apparatus comprising: The measuring device as defined in claim 14 is configured to measure the height position of a measuring region of the substrate; as well as A processing unit is configured to expose the substrate to light while adjusting the position of the substrate in the height direction based on the height position.

17. A method for manufacturing an article, comprising: The substrate is exposed using the exposure method defined in claim 15; The exposed substrate is then developed; as well as Articles are manufactured from the developed substrate.

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