JP2016080525A - Measurement device, measurement method, lithography device and article manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measurement device that is advantageous to a highly accurate measurement of a surface position of a measurement object.SOLUTION: A measurement device comprises: a light shield member 11 that has a plurality of aperture parts, and distributes light from a light source to a plurality of light fluxes using the plurality of aperture parts; a detector 14 that detects front surface reflection light 17a having the plurality of light fluxes reflected upon a front surface of an object, and rear surface reflection light 17b reflected upon a rear surface thereof, and outputs a signal waveform including a plurality of peak waveforms of the front surface reflection light 17a, and a plurality of peak waveforms of the rear surface reflection light 17b; and processing unit 15 that calculates a thickness of the object on the basis of the peak waveform of the front surface reflection light 17a not overlapping the plurality of peak waveforms of the rear surface reflection light 17b in terms of a signal waveform, and the peak waveform of the rear surface reflection light 17b not overlapping the plurality of peak waveforms of the front surface reflection light 17a therein, acquires a relation between the thickness thereof and a measurement error due to the overlapping, identifies the peak waveform of the front surface reflection light 17a on the basis of the thickness thereof and the relation, and calculates a position of a front surface of the object.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a measuring device, a measuring method, a lithography apparatus, and an article manufacturing method.

  An exposure apparatus is a substrate (such as a wafer or a glass plate) coated with a photosensitive agent through a projection optical system on a pattern of an original (reticle, mask, etc.) in a lithography process included in a manufacturing process of a semiconductor device or a liquid crystal display device. ). In such an exposure apparatus, the position (surface position or height) of the surface of the substrate is accurately measured in order to align the surface (exposure surface) of the substrate with the imaging surface of the original pattern, that is, to focus the surface. There is a need. Therefore, the exposure apparatus has an autofocus sensor (AF sensor) that measures the position of the substrate in the optical axis direction of the projection optical system. An AF sensor generally detects a light projecting system that projects light (a plurality of beams) onto the surface of a substrate, a light receiving system that receives reflected light from the surface of the substrate, and light from the light receiving system. And a detection unit that outputs a signal waveform to the processing unit. Here, when the substrate is a translucent substrate such as a glass plate, the light received by the light receiving system includes not only reflected light from the surface of the substrate but also reflected light from the back surface of the substrate. When measuring using such reflected light, the measurement accuracy decreases due to the reflected light from the back surface of the substrate that is not the detection target. Therefore, when using the AF sensor, how to reduce the reflected light on the back surface of the substrate. It is important to extract the reflected light from the surface of the substrate. However, as the thickness of the substrate used in the lithography apparatus is reduced, the waveform of the reflected light from the front surface detected by the detector may overlap with the waveform of the reflected light from the back surface. Therefore, Patent Document 1 discloses a surface position detection device that extracts only the waveform of the surface reflected light using a profile fitting process between the waveform of the reflected light detected by the detection unit and the reference waveform. Patent Document 2 discloses an automatic focusing apparatus that uses only non-overlapping waveforms among signal waveforms including both a waveform of reflected light reflected on the surface of a substrate and a waveform of reflected light reflected on the back surface of the substrate. Disclosure. Patent Document 3 obtains in advance a relationship between an error amount due to overlapping of reflected light from the surface and lower surface of a substance and a known film thickness of the substance, and predicts the error quantity according to the film thickness of the substance A surface position measuring device is disclosed.

JP 2004-273828 A JP 05-281458 A Japanese Examined Patent Publication No. 07-113547

  However, the transmissive substrate to be measured has minute variations in thickness for each substrate and within the substrate, and the overlapping state of the waveform of the front surface reflected light and the back surface reflected light may change depending on the thickness of the substrate. is there. In the apparatus of Patent Document 1, in order to cope with an overlapping state that changes according to the thickness of the substrate, it is necessary to perform multipoint measurement on the substrate and perform profile fitting processing for each measurement point, and throughput is reduced. descend. In addition, in the apparatuses of Patent Document 2 and Patent Document 3, it is not possible to detect the variation in thickness at the measurement target substrate and the measurement position of the substrate, and an error may occur in the calculated measurement value of the substrate. is there.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a measurement device that is advantageous for measuring the surface position of a measurement target with high accuracy, for example.

  In order to solve the above-described problems, the present invention is a measuring apparatus that measures the position of the surface of an object, and has a plurality of openings, and the light from the light source is converted into a plurality of light beams using the plurality of openings. A light blocking member to be distributed, a surface reflected light in which a plurality of light beams are reflected on the surface of the object, and a back surface reflected light reflected on the back surface of the object are detected, and a plurality of peak waveforms of the surface reflected light and a plurality of back surface reflected lights are detected. A detector that outputs a signal waveform including a peak waveform of the surface, a peak waveform of the surface reflected light that does not overlap with the plurality of peak waveforms of the back surface reflected light, and a plurality of peak waveforms of the surface reflected light that do not overlap in the signal waveform Calculate the thickness of the object based on the peak waveform of the reflected light from the back surface, obtain the relationship between the thickness and the measurement error due to the overlap, identify the peak waveform of the reflected light from the surface based on the thickness and the relationship, And a processing unit that calculates the position of the surface And wherein the Rukoto.

  According to the present invention, for example, it is possible to provide a measurement device that is advantageous for measuring the surface position of a measurement target with high accuracy.

It is a figure which shows the structure of the measuring device which concerns on one Embodiment of this invention. It is a figure of the structure of the principal part of the measuring device which shows the flow of received light. It is a figure which shows the flow of the measurement light at the time of measuring a comparatively thick board | substrate. It is a graph which shows the signal waveform at the time of measuring the board | substrate shown in FIG. It is a figure which shows the flow of the measurement light at the time of measuring a comparatively thin board | substrate. It is a graph which shows the signal waveform at the time of measuring the board | substrate shown in FIG. It is a graph which shows an example of a signal waveform in the state where there is no overlap in a signal waveform. It is a graph which shows an example of a signal waveform in the state where there is an overlap in a part of signal waveform. It is a graph which shows an example of a signal waveform in the state where all signal waveforms have an overlap. It is a figure which shows the relationship between the thickness of a board | substrate, and the shift amount position of front and back reflected light. It is a graph which shows the correlation of the thickness of a board | substrate, and a measurement error. It is a graph which shows correlation with the thickness of the board | substrate for every intensity ratio of light, and a measurement error.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  First, a measurement apparatus (measurement method) according to an embodiment of the present invention will be described. The measurement apparatus according to this embodiment is installed in a lithography apparatus such as an exposure apparatus, for example. The measurement apparatus measures the position (surface position or height) of the surface of a substrate (wafer, glass plate, etc.) placed on the stage in the lithography apparatus as a measurement object (object). is there. Hereinafter, the measurement apparatus according to the present embodiment will be described as being installed in an exposure apparatus as an example.

  FIG. 1 is a schematic diagram showing a configuration of an exposure apparatus 100 including a measurement apparatus 22 according to the present embodiment. The exposure apparatus 100 is an exposure apparatus that exposes the substrate 5 via a pattern (for example, a circuit pattern) formed on an original (reticle or mask) 1 by, for example, a step-and-repeat or step-and-scan method. is there. In each of the following drawings including FIG. 1, the Z-axis is taken in parallel to the optical axis direction (vertical direction in the present embodiment) of the projection optical system 4 to be described later, and scanning during exposure is performed in a plane perpendicular to the Z-axis. The Y axis is taken in the direction, and the X axis is taken in the non-scanning direction orthogonal to the Y axis. The exposure apparatus 100 includes an illumination system 3, an original stage 2, a projection optical system 4, a substrate stage 7, a measuring device 22, and a control unit 23. The illumination system 3 illuminates the original 1 by irradiating light (for example, laser light) during exposure. The original stage 2 holds the original 1. The projection optical system 4 projects (images) the pattern formed on the original 1 onto the substrate 5. The substrate stage 7 holds the substrate 5 movably on the XY plane via a holding member (chuck) 6. The substrate stage 7 can move not only in the XY axis directions but also in the Z axis direction, and is also a drive system for focusing. Further, the position of the substrate stage 7 is specified by using a laser interferometer 9 provided for each axis and a mirror 8 installed on the substrate stage 7. Positioned with accuracy.

  The measuring device 22 detects the surface position (the height position in the Z-axis direction in the present embodiment) of the substrate 5 placed on the holding member 6 on the substrate stage 7. The measuring device 22 includes a light source 10, a light projecting system 19, a light receiving system 13, a detector 14, and a processing unit 15. The light source emits light having a wavelength of 500 to 1200 nm, for example. The light projecting system 19 includes a condensing lens (not shown), a light shielding member 11 having a plurality of openings (slits, etc.), and a light projecting lens 12, and the light from the light source 10 condensed by the condensing lens. Is projected onto the surface of the substrate 5 through the light shielding member 11 and the light projecting lens 12. The detection light 16 is guided (projected) obliquely (incident angle θ) toward the surface of the substrate 5 (on the object). The light receiving system 13 guides the received light 17 formed by reflecting the detection light 16 on the substrate 5 to the detector 14. The detector 14 includes, for example, a light receiving element array, receives the received light 17, and outputs (transmits) a detection signal to the processing unit 15. The processing unit 15 performs arithmetic processing based on the detection signal received from the detector 14 to obtain the surface position.

  The control unit 23 can control the operation and adjustment of each component of the exposure apparatus 100. The control unit 23 is configured by, for example, a computer, is connected to each component of the exposure apparatus 100 via a line, and can control each component according to a program or the like. Here, in the above description, the measurement device 22 is configured to include the processing unit 15 that executes arithmetic processing independently of the exposure device 100. On the other hand, when the measuring device 22 is installed in the exposure apparatus 100 as in the present embodiment, the control unit 23 may instead execute the processing executed by the processing unit 15. Further, the control unit 23 may be configured integrally with other parts of the exposure apparatus 100 (in a common casing), or separate from other parts of the exposure apparatus 100 (in a separate casing). It may be configured.

  Next, measurement (measurement method) by the measurement device 22 will be described. FIG. 2 is a schematic diagram showing a main part for explaining the relationship between the detection light 16 and the light reception light 17 in the configuration of the exposure apparatus 100 including the measurement apparatus 22 shown in FIG. When the light from the light source 10 is distributed by the openings of the light blocking member 11 and the detection light 16 formed as a plurality of light beams is reflected by the substrate 5, the surface reflected light 17a reflected by the surface of the substrate 5 and the substrate 5 are reflected. The light receiving light 17 of two components is the back surface reflected light 17b reflected by the back surface of the light. The received light 17 of these two components exists in a mixed state and is guided to the detector 14 via the light receiving system 13, and the surface reflected light 17 a reflected by the surface of the substrate 5 in the detector 14 is a point s. The back-surface reflected light 17b that is incident on the position and reflected by the back surface of the substrate 5 enters the position of the point r. In the exposure apparatus 100, since the focal position of the projection optical system 4 needs to be focused on the surface position of the substrate 5, the measuring device 22 measures the surface position of the substrate 5 based on the surface reflected light 17a. However, when the thickness of the substrate 5 is reduced, the distance between the front surface reflected light 17a and the back surface reflected light 17b is reduced, and the detection signal of the back surface reflected light 17b is mixed with the detection signal of the front surface reflected light 17a as noise. There are things to do.

Here, the relationship between the light beam interval Δd between the front surface reflected light 17a and the back surface reflected light 17b and the thickness of the substrate 5 will be described in detail with reference to FIGS. In order to simplify the description, the case where the light shielding member 11 has one translucent portion, that is, the case where there is one detection light 16 will be described as an example. As shown in FIG. 3, when the substrate 5 is relatively thick and the incident angle θ of the detection light 16 is appropriately set, the light rays of the front surface reflected light 17a and the back surface reflected light 17b incident on the detector 14 are used. The interval is Δd ₁ . In this case, in the signal waveform output from the detector 14, the detection signal A of the front surface reflected light 17a incident on the point s and the detection signal B of the back surface reflected light 17b incident on the point r are as shown in FIG. , They do not overlap because they exist at distant locations. Therefore, the processing unit 15 that has acquired this signal waveform from the detector 14 can determine the peak position s of the detection signal A of the front surface reflected light 17a without being affected by the detection signal B of the back surface reflected light 17b. . However, when the thinned substrate 5 is measured using the detection light 16 incident at the same incident angle θ as in FIG. 3, as shown in FIG. 5, the front surface reflected light 17a and the back surface reflected light are incident on the detector. ray spacing and 17b becomes [Delta] d _2. In this case, in the signal waveform output from the detector 14, the detection signal A of the front surface reflected light 17a and the detection signal B of the back surface reflected light 17b may appear as shown in FIG. Due to this overlap, the detection signal B of the back surface reflected light 17b affects the detection signal A of the surface reflected light 17a as noise, so the processing unit 15 accurately determines the peak position s of the detection signal A of the front surface reflected light 17a. Can not do it.

  Therefore, the measurement apparatus 22 according to an embodiment of the present invention measures the surface position of the substrate 5 in consideration of the measurement error Δu corresponding to the thickness t of the substrate 5. As an example, the measurement device 22 includes a light shielding member 11 having three slits as openings, and irradiates the substrate 5 with three detection lights 16. 7 to 9 are graphs showing signal waveforms for each thickness of the substrate 5 output from the detector 14 applicable to the measuring device 22 in the present embodiment. 7 to 9, the incident angles θ of the detection light 16 on the substrate 5 are all 80 °, and the thickness t of the substrate 5 to be measured is 50 μm or more. By setting it to 50 μm or more, the overlap of the detection signal A of the front surface reflected light 17a and the detection signal B of the back surface reflected light 17b can be made shallower, and it becomes easier to detect a detection signal having no overlap described later. Even if the thickness t of the substrate 5 is less than 50 μm, the detection signal A of the surface reflected light 17a and the back surface reflection are adjusted by adjusting the measuring device 22 so that the incident angle θ of the detection light 16 to the substrate 5 is reduced. It is possible to reduce the overlap of the detection signal B of the light 17b. However, when the incident angle θ is reduced, measurement errors may occur if the signal waveform output from the detector is affected by the processing performed on the substrate 5 in the previous process. The thickness t of the target substrate 5 is desirably 50 μm or more.

  First, a case where a relatively thick substrate (for example, 0.4 mm) 5 is measured will be considered with reference to FIG. In this case, three peak waveforms indicating the peak value a and the peak positions s1 to s3 serving as the detection signal A of the front surface reflected light 17a, and the peak value b and the peak positions r1 to r3 serving as the detection signal B of the back surface reflected light 17b are represented. The three peak waveforms shown are output as non-overlapping waveforms. Therefore, the detection signal A of the front surface reflected light 17a does not include an error due to the detection signal B of the back surface reflected light 17b. Therefore, the processing unit 15 can determine the peak value a and the peak positions s1 to s3 of the surface reflected light 17a based on the signal waveform output from the detector 14, and can measure the surface position of the substrate 5.

  Next, consider the case of measuring a thinned substrate (as an example, 0.14 mm) 5 in comparison with FIG. In this case, the light ray interval Δd between the front surface reflected light 17a and the back surface reflected light 17b is smaller than that in the case of FIG. Therefore, as shown in FIG. 8, in the signal waveform output from the detector 14, the peak waveform indicating the peak positions s2 and s3 in the detection signal A of the front surface reflected light 17a is the peak of the detection signal B of the back surface reflected light 17b. It overlaps with the peak waveform indicating the positions r1 and r2. Further, when the substrate 5 is further thinned (for example, 0.06 mm), as shown in FIG. 9, all three peak waveforms of the detection signal A of the front surface reflected light 17a and the detection signal B of the back surface reflected light 17b are obtained. Overlap.

  As shown in FIGS. 8 and 9, when the thickness t of the substrate 5 is reduced, the substrate 5 starts to overlap with the r1 side of the detection signal B of the back surface reflected light 17b from the s3 side of the detection signal A of the front surface reflected light 17a. When the detection signals A and B of the front surface reflected light 17a and the back surface reflected light 17b overlap, the detection signal B of the back surface reflected light 17b affects the peak positions s1 to s3 and the peak value a of the front surface reflected light 17a as noise. There is. Therefore, the processing unit 15 cannot determine the accurate detection signal A of the surface reflected light 17a from the signal waveform output from the detector 14, and cannot accurately measure the surface position of the substrate 5. Therefore, the measurement device 22 calculates the thickness t of the substrate 5 from the signal waveform output from the detector 14 and predicts the measurement error Δu of the surface position of the substrate 5 based on the thickness t of the substrate 5.

First, a method for calculating the thickness t of the substrate 5 to be measured will be described. FIG. 10 is a schematic diagram showing the relationship between the thickness t of the substrate 5 and the shift amount Δs of the front and rear surface reflected light positions. As shown in FIG. 10, the thickness of the substrate is t, the refractive index of the substrate is N, the incident angle of the measurement light is θ, the magnification of the light receiving system is β, Let the shift amount be Δs. In this case, these relationships can be expressed by the following formulas 1 and 2.
Δs = β × (2 × t × tan θ ′) × sin θ (Formula 1)
θ ′ = sin−1 (sin θ / N) (Formula 2)

As shown in FIG. 7, when the detection signals A and B of the front surface reflected light 17a and the back surface reflected light 17b do not overlap, the shift amount Δs of the front and back surface reflected light position is the back surface reflection corresponding to the peak position of the front surface reflected light 17a. It is calculated from the peak position of the light 17b. In this case, using the peak positions s1 to s3 of the detection signal A of the front surface reflected light 17a and the peak positions r1 to r3 of the detection signals of the back surface reflected light 17b, the shift amount Δs of the front and rear surface reflected light positions is expressed by the following equation (3). Can be expressed as
Δs = s1-r1 = s2-r2 = s3-r3 (Formula 3)

  However, if the detection signal B of the back surface reflected light 17b begins to overlap the detection signal A of the front surface reflected light 17a due to the thinning of the substrate 5, the processing unit 15 cannot discriminate all the peak positions of each reflected light and reflects the front and back surfaces. The shift amount Δs of the optical position cannot be detected from the signal waveform. That is, when the thickness t of the substrate 5 is reduced, the detection signal B of the back surface reflected light 17b begins to overlap the detection signal A of the front surface reflected light 17a as shown in the signal waveforms of FIGS. As the thickness t changes, the number of overlapping peak waveforms of the detection signals A and B of the front surface reflected light 17a and the back surface reflected light 17b and the position thereof also change. Cannot be calculated from the signal waveform output by the detector 14.

Therefore, the processing unit 15 calculates the thickness t from the relationship between the peak position s1 of the left peak waveform of the front surface reflected light 17a and the peak position r3 of the right peak waveform of the back surface reflected light 17b. As the thickness t of the substrate 5 decreases, the number of peak waveforms that overlap among the three peak waveforms of the detection signals A and B of the front surface reflected light 17a and the back surface reflected light 17b increases. Of the waveforms of the detection signals A and B of the reflected light, the peak waveform that overlaps last is a peak waveform that exists at both ends of the signal waveform output by the detector 14. That is, in the present embodiment, the peak position s1 of the left peak waveform of the front surface reflected light 17a and the peak position r3 of the right peak waveform of the back surface reflected light 17b correspond to this. In the signal waveform output from the detector 14, the back surface reflected light 17 b has a lower peak value b than the front surface reflected light 17 a because it is refracted and reflected in the substrate 5. Furthermore, the position of the peak waveform of the detection signal B of the back surface reflected light 17b with respect to the detection signal A of the surface reflected light 17a depends on the specifications of the detector 14 and the light receiving system 13, and when using the same measuring device 22, the surface reflected light The detection signal A of 17a is always present on the left or right side. Therefore, for example, the processing unit 15 that has obtained the signal waveform as shown in FIG. 8 has one waveform having a small peak among the four waveforms having peaks, which is the peak position r3 of the back surface reflected light 17b, and is present on the leftmost side. It can be determined that the waveform to be performed is the peak position s1 of the surface reflected light 17a. The relationship between the two peak positions s1 and r1 and the shift amount Δs of the front and rear surface reflected light positions is expressed by the following equation 4 where P is the pitch between the peak waveforms, that is, the pitch between the light shielding portions of the light shielding member 11. be able to.
Δs = s1−r1 = s1− (r3−2 × P)
= S3-r3 = (s1 + 2 * P) -r3 (Formula 4)

  The pitch P between the peak waveforms is usually common in the detection signals A and B of the front surface reflected light 17a and the back surface reflected light 17b. However, when the plurality of light shielding portions of the light shielding member 11 are arranged at different pitches and the pitch P is different in the respective detection signals of the front surface reflected light 17a and the back surface reflected light 17b, or the pitch P is different between the front and back surface reflected light. There is a case. In this case, the relationship between the peak positions s and r and the pitch P corresponding to each reflected light is obtained using peak waveforms that do not overlap each other, and between the detection signals A and B of the front surface reflected light 17a and the back surface reflected light 17b, respectively. Therefore, the pitch P may be reflected in the expression 4 that is the same.

  Further, consider the case where the same substrate 5 is measured at a position where the thickness t is different, or the substrate 5 where the thickness t is different. In this case, in the signal waveform when the substrate 5 having a known thickness t is measured, the position difference (s1-s3 in FIG. 8) of the detection signals that do not overlap among the reflected lights on the detector 14 is used as a reference. The change from the reference may be calculated as the shift amount Δs.

  By the above method, the shift amount Δs of the front and back surface reflected light positions can be obtained regardless of whether the waveforms overlap, and the substrate 1 can be obtained from the shift amount Δs of the front and back surface reflected light positions using Equations 1 and 2. A thickness t of 5 can be calculated.

  Next, a method for calculating the measurement error Δu based on the thickness t of the substrate 5 calculated as described above will be described. The measurement error Δu is an error generated when the thickness t becomes thin and the detection signals A and B of the front surface reflected light 17a and the back surface reflected light 17b overlap as shown in FIGS. First, the processing unit 15 creates a correlation table indicating the relationship between the thickness t of the substrate 5 and the measurement error Δu when the measurement device 22 is used. FIG. 11 is an example of a correlation table showing the relationship between the thickness t of the substrate 5 and the measurement error Δu. This correlation table uses the measuring device 22 to measure the height of the substrate 5 whose thickness t is known, and the height (position) of the substrate 5 predicted from the thickness t of the substrate 5 and the measuring device 22. The measurement error Δu can be calculated by comparing the measurement results obtained by the above. In addition, this correlation table calculates the measurement error Δu by comparing the height (position) of the substrate 5 predicted from the thickness t of the substrate 5 calculated by the above-described method and the measurement result by the measurement device 22. May be created. However, in this correlation table, for example, as shown in FIG. 7, the measurement error when the detection signals A and B of the front surface reflected light 17a and the back surface reflected light 17b do not overlap is set as the reference value u0. Further, as the detection light 16 when creating the correlation table, the detection light 16 for actually measuring the substrate 5 to be measured or the detection light having a waveform substantially equivalent thereto is used.

  The processing unit 15 calculates the thickness t of the substrate 5 from the signal waveform output from the detector 14 when measuring the measurement target substrate 5 by the above-described method, and sets the thickness t in the correlation table created in advance. The corresponding measurement error Δu is determined. Then, the processing unit 15 subtracts the measurement error Δu corresponding to the thickness t from the raw value (u0 + Δu) calculated based on the signal waveform from the detector 14. Thereby, the detection signal A of the front surface reflected light 17a can be specified, and the true value of the surface position of the substrate 5 which does not include an error due to the back surface reflected light 17b can be obtained.

  As described above, according to the present embodiment, the thickness t of the substrate 5 and the measurement error Δu caused by the overlap of each reflected light are calculated, thereby taking into account the variation in the thickness t of the substrate 5 to be measured. The surface position of the substrate 5 can be measured with high accuracy.

  Note that the measurement apparatus 22 of the present embodiment uses a correlation table indicating the relationship between the thickness t of the substrate 5 and the measurement error Δu. However, the intensity ratio between the front surface reflected light 17a and the back surface reflected light 17b may differ depending on the material, thickness, and the like of the substrate 5. In this case, the overlapping state of the front surface reflected light 17a and the back surface reflected light 17b that causes the measurement error Δu depends on the relationship of the intensity of the back surface reflected light 17b with respect to the front surface reflected light 17a. Therefore, a configuration may be adopted in which a correlation table is created for each reflected light intensity ratio and the measurement error Δu is obtained using the correlation table. FIG. 12 is a graph showing a correlation table between the thickness t of the substrate 5 and the measurement error Δu for each reflected light intensity ratio. In this correlation table, the reflected light intensity ratio means the back surface reflected light intensity with respect to the front surface reflected light intensity, and is created with a value of 0.33 to 1.0 as an example. The processing unit 15 calculates a reflected light intensity ratio from the signal waveform acquired from the detector 14 in addition to the thickness t of the substrate 5, and a measurement error corresponding to the calculated reflected light intensity ratio and the thickness t of the substrate 5. Find Δu.

  In addition, the measurement apparatus 22 that includes the light shielding member 11 having three slits as the opening and irradiates the substrate 5 with the three detection lights 16 has been described as an example. However, the present invention is not limited to this configuration. Any structure that irradiates the substrate 5 with more than 16 detection lights 16 may be used.

  In this embodiment, an example of an exposure apparatus has been described as the lithography apparatus. However, the lithography apparatus is not limited to this and may be another lithography apparatus. For example, it may be a drawing apparatus that performs drawing on a substrate (upper photosensitive agent) with a charged particle beam such as an electron beam, or an imprint material on the substrate is molded (molded) with a mold (mold). An imprint apparatus or the like that forms a pattern thereon may also be used.

(Product manufacturing method)
The method for manufacturing an article according to an embodiment is suitable for manufacturing an article such as a micro device such as a semiconductor device or an element having a fine structure. The manufacturing method includes a step of forming a pattern (for example, a latent image pattern) on an object (for example, a substrate having a photosensitive agent on the surface) by using the above-described lithography apparatus, and a processing of the object on which the pattern is formed in the step. (For example, a development step). Further, the manufacturing method may include other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, and the like). The method for manufacturing an article according to the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article as compared with the conventional method.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation or change is possible within the range of the summary.

DESCRIPTION OF SYMBOLS 11 Light shielding member 14 Detector 15 Processing part 17a Front surface reflected light 17b Back surface reflected light

Claims (6)

A measuring device for measuring the position of the surface of an object,
A light shielding member that has a plurality of openings and distributes light from a light source into a plurality of light fluxes using the plurality of openings;
The plurality of light fluxes are detected from the surface reflected light reflected from the surface of the object and the back surface reflected light reflected from the back surface of the object, and a plurality of peak waveforms of the surface reflected light and a plurality of the back surface reflected light are detected. A detector that outputs a signal waveform including a peak waveform;
Based on the peak waveform of the surface reflected light that does not overlap with the plurality of peak waveforms of the back surface reflected light in the signal waveform and the peak waveform of the back surface reflected light that does not overlap with the plurality of peak waveforms of the surface reflected light. The thickness of the object is calculated, the relationship between the thickness and the measurement error due to the overlap is obtained, the peak waveform of the surface reflected light is specified based on the thickness and the relationship, and the position of the surface of the object A measurement device comprising: a processing unit that calculates   The measurement apparatus according to claim 1, wherein the peak waveforms of the front surface reflected light and the back surface reflected light that do not overlap exist at both ends in the signal waveform.   The processing unit calculates a reflected light intensity ratio between the front surface reflected light and the back surface reflected light based on the peak waveforms of the front surface reflected light and the back surface reflected light that do not overlap, and for each reflected light intensity ratio The measurement apparatus according to claim 1, wherein the relationship is acquired. A measurement method for measuring the position of the surface of an object,
Irradiating the object with a plurality of luminous fluxes;
Detecting the surface reflected light reflected by the surface of the object and the back reflected light reflected by the back surface of the object, the plurality of peak waveforms of the surface reflected light and the plurality of peaks of the back reflected light. Outputting a signal waveform including a waveform;
Based on the peak waveform of the surface reflected light that does not overlap with the plurality of peak waveforms of the back surface reflected light in the signal waveform and the peak waveform of the back surface reflected light that does not overlap with the plurality of peak waveforms of the surface reflected light. Calculating the thickness of the object;
Obtaining a relationship between the thickness and a measurement error due to the overlap, specifying a peak waveform of the surface reflected light based on the thickness and the relationship, and calculating a position of the surface of the object. Characteristic measuring method. A lithographic apparatus for forming a pattern on a substrate,
The measurement apparatus according to any one of claims 1 to 3, which measures a position of a surface of the substrate as the object.
A lithographic apparatus, comprising: Forming a pattern on a substrate using the lithographic apparatus according to claim 5;
Processing the substrate on which the pattern is formed in the step;
A method for producing an article comprising:

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