Pattern forming apparatus and method for manufacturing article

Abstract

To provide a pattern formation device advantageous in view of alignment accuracy.SOLUTION: A pattern formation device includes: a first measurement part including a detection part configured to use an alignment optical system and obtain an image of a mark on a substrate, and an image processing part configured to execute image processing on the image of the mark obtained by the detection part and measure a position of the mark; a second measurement part having a relative position fixed with regard to the first measurement part and configured to measure a surface position of the substrate; and a control part configured to control a position of the substrate according to the position of the mark measured at the first measurement part and control to form a pattern on the substrate. The control part controls the first measurement part to start obtaining the image of the mark by the first measurement part even when the surface position of the substrate is not within a focal depth of the alignment optical system, and executes a focus control of controlling a surface position of the substrate according to a measurement result of the surface position of the substrate by the second measurement part while obtaining the image of the mark.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a pattern forming apparatus and a method for manufacturing an article. [Background technology]

[0002] 2. Description of the Related Art When manufacturing devices such as semiconductor elements, liquid crystal display elements, and thin-film magnetic heads, pattern forming apparatuses such as exposure apparatuses are used that project and transfer a pattern from a reticle onto a substrate such as a wafer using a projection optical system.

[0003] As electronic devices become smaller and demand increases, pattern formation equipment must balance the miniaturization of semiconductor elements such as memories and MPUs with productivity. Therefore, pattern formation equipment such as exposure devices are required to improve basic performance such as resolution, overlay accuracy, and throughput.

[0004] As semiconductor elements become finer, improved overlay accuracy is required, which in turn requires higher accuracy in alignment to align the relative positions of the reticle and substrate. Two types of alignment, pre-alignment and fine alignment, are known as substrate alignment techniques that use alignment marks provided on the substrate.

[0005] Pre-alignment involves detecting the amount of misalignment of a substrate sent onto the substrate stage, and roughly aligning (positioning) the substrate by correcting the misalignment so that fine alignment can begin. Fine alignment involves measuring the position of the substrate held by the substrate stage with high accuracy, and precisely aligning (positioning) the substrate so that the substrate alignment error falls within an acceptable range.

[0006] On the other hand, there is a demand for faster alignment to improve throughput. Patent Document 1 discloses a technique for speeding up alignment by shortening the time it takes to detect an alignment mark. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2017-215556 A Summary of the Invention [Problem to be solved by the invention]

[0008] Specifically, Patent Document 1 discloses a mark detection device capable of simultaneously detecting multiple alignment marks using multiple alignment sensors. The height position of the substrate is adjusted so that the alignment mark to be detected is located within the focal depth of the optical system of each alignment sensor, and then the multiple alignment marks are detected simultaneously, thereby shortening the detection time for the alignment marks.

[0009] However, in the mark detection device of Patent Document 1, the height position of the substrate is not adjusted during the alignment mark detection operation, so that the alignment mark may be detected when the height position of the substrate is not within the focal depth of the optical system of the alignment sensor, which may result in a decrease in the detection accuracy of the alignment mark and a decrease in the alignment accuracy.

[0010] An exemplary object of the present invention is to provide a pattern forming apparatus that is advantageous in terms of alignment accuracy. [Means for solving the problem]

[0011] In order to achieve the above object, a pattern forming apparatus according to one aspect of the present invention includes: an alignment optical system for aligning an image of a mark on a substrate; signal a detection unit for acquiring an image of the mark acquired by the detection unit; About Signalsa first measurement unit including an image processing unit that performs image processing to measure the position of the mark; a second measurement unit that is fixed in position relative to the first measurement unit and measures the surface position of the substrate; and a control unit that controls the position of the substrate based on the position of the mark measured by the first measurement unit to form a pattern on the substrate. To The control unit controls the image of the mark by the first measurement unit even if the surface position of the substrate is not within the focal depth of the alignment optical system. signal Start getting To The first measurement unit is controlled to measure an image of the mark. signal While acquiring the above-mentioned signal, focus control is performed to adjust the surface position of the substrate so that the surface position of the substrate is included within the focal depth of the alignment optical system, based on the measurement result of the surface position of the substrate by the second measurement unit. Effect of the Invention

[0012] According to the present invention, for example, it is possible to provide a pattern forming apparatus which is advantageous in terms of alignment accuracy. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic diagram showing a configuration of an exposure apparatus according to one aspect of the present invention. [Diagram 2] 2 is a schematic diagram showing the configuration of a substrate alignment optical system and the optical path of alignment light; [Diagram 3] 2 is a schematic diagram showing the configuration of a substrate focus optical system and the optical path of focus light; FIG. [Figure 4] FIG. 2 is a schematic diagram showing focus control according to the first embodiment of the present invention. [Diagram 5] FIG. 11 is a schematic diagram showing focus control according to the second embodiment of the present invention. [Figure 6] 3A and 3B are diagrams showing the arrangement and configuration of alignment marks provided on a substrate; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In each drawing, the same reference numerals are used to refer to the same components, and duplicated explanations will be omitted.

[0015] FIG. 1 is a schematic diagram showing the configuration of an exposure apparatus 1 as a pattern forming apparatus of the present invention. The exposure apparatus 1 is a lithography apparatus used in the manufacture of devices such as semiconductor elements, liquid crystal display elements, and thin-film magnetic heads as articles, and forms a pattern on a substrate. The exposure apparatus 1 exposes the substrate by a step-and-scan method or a step-and-repeat method. Note that the present invention is not limited to exposure apparatuses, and can also be applied to lithography apparatuses and imprinting apparatuses that form a latent image pattern of a resist on a substrate by irradiating the substrate with EUV light.

[0016] The exposure apparatus 1 has a main controller 100, a light source controller 110, an alignment light source 120, an image processor 130, a stage controller 140, an interferometer 150, a reticle (original) alignment measurement unit 160, and a reticle stage 171. The exposure apparatus 1 also has a projection optical system 180, a substrate alignment measurement unit (first measurement unit) 190, a substrate stage 200, a focus light source 220, and a substrate focus measurement unit (second measurement unit) 230.

[0017] The reticle stage 171 moves while holding a reticle 170 illuminated by an illumination optical system (not shown). A pattern to be transferred to a substrate 210 is drawn on the reticle 170. The projection optical system 180 projects the pattern of the reticle 170 onto the substrate 210. The substrate stage 200 is a movable holder that holds a substrate, and in this embodiment, moves while holding the substrate 210.

[0018] The reticle alignment measurement unit 160 is used for alignment of the reticle 170. The reticle alignment measurement unit 160 includes, for example, an image pickup element 161 configured with an accumulation type photoelectric conversion element, and an optical system 162 that guides light from an alignment mark provided on the reticle 170 to the image pickup element 161. The substrate alignment measurement unit 190 is used for alignment of the substrate 210. In this embodiment, the substrate alignment measurement unit 190 is an off-axis optical system, and detects an alignment mark 211 provided on the substrate 210.

[0019] The main controller 100 includes a CPU, a memory, and the like, and controls the overall operation of the exposure apparatus 1. The main controller 100 controls each part of the exposure apparatus 1 to perform an exposure process for exposing the substrate 210 and processes related thereto. In this embodiment, the main controller 100 controls the position of the substrate stage 200 in a plane perpendicular to the optical axis of the projection optical system, based on the positions of the alignment marks formed on the reticle 170 and the alignment marks 211 formed on the substrate 210. In other words, the main controller 100 aligns the reticle 170 and the substrate 210, for example, performs global alignment, and executes an exposure process for the substrate 210 in a state in which the reticle 170 and the substrate 210 are aligned.

[0020] The alignment light source 120 includes a halogen lamp or the like, and illuminates the alignment mark 211 formed on the substrate 210. The light source control unit 110 controls the illumination intensity of the light from the alignment light source 120, that is, the alignment light for illuminating the alignment mark 211.

[0021] The image processing unit 130 performs image processing on image signals (detection signals) from the imaging element 161 in the reticle alignment measurement unit 160 and the imaging element in the substrate alignment measurement unit 190 to measure the position of the alignment mark. In this embodiment, the image processing unit 130 and the substrate alignment measurement unit 190 function as a measurement device that measures the position of the alignment mark 211 formed on the substrate 210.

[0022] The substrate focus measurement unit 230 measures the surface position of the substrate 210. The measurement result is processed by the signal processing unit 240, and the main control unit 100 performs focus control to adjust the height of the substrate 210 so that the surface position of the substrate 210 is included within the focal depth of the alignment optical system constituting the substrate alignment measurement unit 190. The substrate focus measurement unit 230 has a fixed position relative to the substrate alignment measurement unit 190. The interferometer 150 measures the position of the substrate stage 200 by irradiating light onto a mirror provided on the substrate stage 200 and detecting the light reflected by the mirror. The stage control unit 140 moves (drives and controls) the substrate stage 200 to an arbitrary position based on the position of the substrate stage 200 measured by the interferometer 150.

[0023] In the exposure apparatus 1, light (exposure light) from an illumination optical system passes through a reticle 170 held on a reticle stage 171 and enters a projection optical system 180. Since the reticle 170 and the substrate 210 are in an optically conjugate positional relationship, the pattern of the reticle 170 is transferred via the projection optical system 180 onto the substrate 210 held on a substrate stage 200.

[0024] 2 is a schematic diagram showing the configuration of the substrate alignment measurement unit 190 and the optical path of the alignment light. The substrate alignment measurement unit 190 functions as a detection unit that detects an alignment mark 211 formed on a substrate 210 and generates a detection signal, in this embodiment, an image signal. Each optical system included in the substrate alignment measurement unit 190 constitutes a substrate alignment optical system.

[0025] The illumination light source 20 of the substrate alignment measurement unit 190 generates infrared light (for example, 1000 to 1500 nm) and visible light (for example, 400 to 800 nm). The light from the alignment light source 120 passes through a first relay optical system 21, a wavelength filter plate 22, and a second relay optical system 23, and reaches an aperture stop 24 arranged on the pupil plane of the substrate alignment optical system.

[0026] The wavelength filter plate 22 includes a plurality of filters with different transmission wavelength bands, and switches between the filters in response to a command from the main control unit 100. The aperture stop 24 includes a plurality of stops with different illumination σ, and the illumination σ can be changed by switching between the stops in response to a command from the main control unit 100. In FIG. 2, the wavelength filter plate 22 and the aperture stop 24 each include a plurality of filters and a plurality of stops, but a filter and a stop may be added in addition to the wavelength filter plate 22 and the aperture stop 24. The wavelength filter plate 22 in FIG. 2 includes a filter that transmits visible light and a filter that transmits infrared light, and the wavelength of light used to detect the mark can be selected by switching between these filters.

[0027] The light that reaches the aperture stop 24 passes through the first illumination optical system 25 and the second illumination optical system 27 and is guided to the polarizing beam splitter 28. The S-polarized light perpendicular to the paper surface reflected by the polarizing beam splitter 28 passes through the NA stop 26, the prism 63, and the λ / 4 plate 29 to be converted into circularly polarized light, and passes through the objective lens 30 to illuminate the mark 211 formed on the substrate 210 (the illumination light is shown by the solid line in FIG. 2). The NA of the NA stop 26 can be changed by changing the aperture amount. The aperture amount of the NA stop 26 can be changed by a command from the main control unit 100. The prism 63 has the property of transmitting the alignment light.

[0028] The reflected light, diffracted light, and scattered light generated from the mark 211 (indicated by dotted lines in FIG. 2) again passes through the objective lens 30 and the λ / 4 plate 29, and is converted into P-polarized light parallel to the paper surface. The P-polarized light passes through the prism 63 and the polarizing beam splitter 28, and passes through the relay lens 31, the first imaging optical system 32, the optical member 35, the second imaging optical system 33, and the optical member 38 that adjusts the wavelength shift difference. The P-polarized light that has passed through the optical member 38 forms a detection signal of the mark 211 on a photoelectric conversion element 34 (for example, a CCD camera).

[0029] Next, the configuration and optical path of the substrate focus measurement unit 230 will be described with reference to Fig. 3. As described above, the substrate focus measurement unit 230 measures the surface position of the substrate 210. Based on the measurement result, the main control unit 100 executes focus control to adjust the height of the substrate 210 so that the surface position of the substrate 210 is included within the focal depth of the substrate alignment optical system.

[0030] 3(a) shows how focus light is irradiated onto substrate 210. The focus light irradiated from focus light source 220 passes through lens 56 and illuminates pattern plate 57. Focus light source 220 generates light in the visible light range. Pattern plate 57 is a glass substrate on which a slit pattern is drawn, and the focus light illuminating the slit pattern drawn in the center of pattern plate 57 passes through lens 58, is reflected by mirror 59, and reaches lens 60. For convenience of explanation, only the chief ray of the focus light from pattern plate 57 onwards is shown, but in reality it is a ray with a numerical aperture.

[0031] The focus light does not reach the center of the lens 60 but reaches a position eccentric from the center of the lens 60, and is refracted by the lens 60, passes through the reference mirror 61, and reaches the lens 62. The light that reaches the lens 62 also does not reach the center of the lens 62 but reaches a position eccentric from the center of the lens 62. The focus light refracted by the lens 62 reaches the prism 63. The prism 63 has a characteristic of reflecting the focus light and transmitting the alignment light. The focus light reflected by the prism 63 transmits the λ / 4 plate 29 and reaches the lens 30. The focus light does not reach the center of the lens 30 but reaches a position eccentric from the center of the lens 30, and is refracted by the lens 30, so that it is obliquely incident on the substrate 210 at an incident angle θ as shown in FIG. 3(a).

[0032] 3(b), the optical path of the focus light obliquely incident on the substrate 210 until it is received by the focus detection sensor 65 will be described. The focus light reflected by the substrate 210 is reflected by the substrate 210 at the same angle θ as when it was incident on the substrate 210, and reaches the lens 30. At this time, the focus light does not reach the center of the lens 30, but reaches a position eccentric from the center of the lens 30, and is refracted by the lens 30, so that it passes through the λ / 4 plate 29 and reaches the prism 63.

[0033] The focus light reflected by the prism 63 reaches the lens 62. At this time, the focus light does not reach the center of the lens 62, but reaches a position eccentric from the center of the lens 62, and is refracted by the lens 62, passes through the reference mirror 61, and reaches the lens 60. At this time, the focus light does not reach the center of the lens 60, but reaches a position eccentric from the center of the lens 60, and is refracted by the lens 60, so that the focus light reaches the center of the lens 64, passes through the lens 64, and is received by the focus detection sensor 65.

[0034] 3, a state has been described in which the substrate focus measurement unit 230 obliquely incidents focus light on the substrate 210, and the focus light reflected by the substrate 210 is received by the focus detection sensor 65. From the above description, it can be seen that the position at which the focus light is received by the focus detection sensor 65 shifts as the substrate 210 moves in the focus direction (Z direction). From this shift in the light receiving position, the surface position of the substrate 210 can be measured.

[0035] As described above, the substrate alignment optical system constituting the substrate alignment measurement unit 190 and the optical system constituting the substrate focus measurement unit 230 share a portion of the same system.

[0036] This makes it possible to prevent the combined configuration of the substrate alignment measurement unit 190 and the substrate focus measurement unit 230 from becoming too large.

[0037] In the exposure apparatus of the present invention, the substrate focus measurement unit 230 measures the surface position of the substrate 210 in parallel with the substrate alignment measurement unit 190 generating an image signal of the alignment mark 211. Furthermore, the main controller 100 performs focus control in parallel with the substrate alignment measurement unit 190 generating an image signal of the alignment mark 211. A specific embodiment of the focus control will be described below.

[0038] Example 1 The focus control of the first embodiment will be described with reference to Fig. 4. In Fig. 4, the horizontal axis indicates time T, and the vertical axis indicates the position of the substrate 210 in the height direction (Z-axis direction). As shown in Fig. 4, the position of the substrate 210 in the height direction may change over time. Therefore, at timing A when generation of an image signal of the alignment mark 211 starts, the surface position of the substrate 210 may not be within the focal depth of the substrate alignment optical system.

[0039] Therefore, in this embodiment, the substrate focus measurement unit 230 measures the surface position of the substrate 210 at the timing when the substrate alignment measurement unit 190 starts generating an image signal of the alignment mark 211. Then, the main control unit 100 performs focus control based on the measurement result of the surface position of the substrate 210 so that the surface position of the substrate 210 is located within the focal depth of the substrate alignment optical system.

[0040] Generally, the time required for focus control is short compared to the time required to acquire an image signal of the alignment mark 211, so focus control can be performed multiple times while an image signal of the alignment mark 211 is acquired. In Fig. 4, the surface position of the substrate 210 is measured again at timings B and C, and the main controller 100 performs focus control again based on the measurement results. This allows the substrate 210 to be positioned within the focal depth of the substrate alignment optical system for most of the period during which the image signal of the alignment mark 211 is acquired.

[0041] In this embodiment, an example has been shown in which focus control is performed three times during the period in which an image signal of the alignment mark 211 is acquired, but it is preferable to perform focus control at least two times.

[0042] Example 2 Next, the focus control of the second embodiment will be described with reference to Fig. 5. In Fig. 5, the horizontal axis indicates time T, and the vertical axis indicates the position of the substrate 210 in the height direction (Z-axis direction). In this embodiment, the substrate focus measurement unit 230 measures the surface position of the substrate 210 at the timing when the substrate alignment measurement unit 190 starts generating an image signal of the alignment mark 211. Then, the main control unit 100 performs focus control to move the position of the substrate 210 toward the focal position of the substrate alignment optical system based on the measurement result of the surface position of the substrate 210.

[0043] In the focus control of the second embodiment, the position of the substrate 210 in the height direction is moved from the start of generation of an image signal of the alignment mark 211 to the end of generation. This makes it possible to maintain the surface position of the substrate 210 within the focal depth of the substrate alignment optical system with a control simpler than that of the first embodiment.

[0044] As described above, by performing focus control in parallel with generating an image signal of the alignment mark 211, it is possible to acquire the image signal of the alignment mark 211 with high accuracy. The acquired image signal is read out by the image processing unit 130. The image processing unit 130 performs pattern matching processing on the image signal to obtain the position of the alignment mark 211 on the imaging surface. However, the image processing is not limited to pattern matching processing, and may be any processing capable of obtaining the position of the alignment mark 211. Therefore, the image processing may be, for example, edge detection processing.

[0045] Based on the position information of the alignment mark 211 thus obtained, the exposure apparatus 1 performs two types of alignment: pre-alignment and fine alignment. Pre-alignment is to detect the amount of positional deviation of the substrate 210 sent from the substrate transport system to the substrate stage 200, and roughly align (position) the substrate 210 so that fine alignment can be started. Fine alignment is to measure the position of the substrate 210 held by the substrate stage 200 with high accuracy, and precisely align (position) the substrate 210 so that the alignment error of the substrate 210 falls within an allowable range.

[0046] The arrangement of alignment marks related to the alignment process and the flow of the alignment process will be described with reference to Fig. 6. As shown in Fig. 6(a), a plurality of shot areas 301, which are pattern transfer areas of a reticle, are arranged in a grid pattern on the substrate 210. The same pattern is usually formed in the shot areas 301. As shown in Fig. 6(b), a pre-alignment mark PAM and a fine alignment mark FAM are provided as alignment marks on the scribe lines around the pattern area (circuit pattern area) RPR of the shot area 301.

[0047] A general alignment process will be described below. In the alignment process, as shown in Fig. 6(a), a shot area for detecting an alignment mark is selected from a plurality of shot areas 301 on a substrate 210, and the alignment mark of each shot area is detected. For example, in Fig. 6, a sample shot area 302 is selected as a shot area for detecting an alignment mark by pre-alignment.

[0048] In the pre-alignment, two or more shot areas are selected from the multiple shot areas 301 as sample shot areas 302. In each sample shot area 302, the position of the pre-alignment mark PAM is measured using an image signal from the imaging element.

[0049] Also, sample shot areas 303 are selected as shot areas for detecting alignment marks in fine alignment. In fine alignment, a greater number of sample shot areas 303 than the number of sample shot areas 302 are selected from the multiple shot areas 301 according to the alignment accuracy required to expose the substrate 210. In each sample shot area 303, position measurement of the fine alignment mark FAM is performed using an image signal.

[0050] In this way, the exposure apparatus 1 of the present embodiment can accurately acquire an image signal of the alignment mark 211, and as a result, can improve the alignment accuracy. Therefore, the exposure apparatus 1 can provide high-quality devices (semiconductor devices, liquid crystal display devices, etc.) with high overlay accuracy.

[0051] The method for manufacturing an article according to the embodiment of the present invention is suitable for manufacturing an article such as a microdevice such as a semiconductor device or an element having a fine structure. The manufacturing method includes a step of exposing a substrate coated with a photosensitive agent using an exposure apparatus 1 (a step of forming a pattern on the substrate) and a step of developing the exposed substrate (a step of processing the substrate on which the pattern has been formed). Following the above-mentioned formation step, the manufacturing method may include other well-known steps (oxidation, film formation, deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.). 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 compared to the conventional methods.

[0052] Although the preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention.

[0053] (Modification) In the above-described embodiment, focus control is performed in parallel with generating an image signal of the alignment mark 211, but focus control may also be performed before generating an image signal of the alignment mark 211 depending on the position detection result of the alignment mark 211.

[0054] Specifically, the position of the alignment mark 211 is measured by a measurement mode selected from the two measurement modes described below. In the first measurement mode, the measurement of the surface position of the substrate 210 by the substrate focus measurement unit 230 and the measurement of the position of the mark on the substrate 210 by the substrate alignment measurement unit 190 are performed in parallel. On the other hand, in the second measurement mode, the measurement of the surface position of the substrate 210 by the substrate focus measurement unit 230 is performed independently of the measurement of the position of the mark on the substrate 210 by the substrate alignment measurement unit 190.

[0055] When selecting the measurement mode, the position measurement result of the alignment mark 211 detected while changing the height of the substrate 210 is compared with the position measurement result of the alignment mark 211 detected without changing the height of the substrate 210. If the difference between the two position measurement results is equal to or less than a predetermined value, the first measurement mode is selected because there is no problem in measuring the surface position of the substrate 210 by the substrate focus measurement unit 230 and measuring the position of the mark on the substrate 210 by the substrate alignment measurement unit 190 in parallel. On the other hand, if the difference between the two position measurement results exceeds a predetermined value, the second measurement mode is selected.

[0056] The measurement mode is selected, for example, at the timing when exposure processing for the first substrate in a lot is started.

[0057] By measuring the position of the alignment mark 211 in the optimum measurement mode, it is possible to reduce the time required for position measurement without reducing the position measurement accuracy.

[0058] (Production method of the article) Next, a method for manufacturing an article (such as a semiconductor IC element, a liquid crystal display element, a color filter, or a MEMS) using the above-mentioned exposure apparatus will be described. The article is manufactured by exposing a substrate (such as a wafer or a glass substrate) coated with a photosensitive agent using the above-mentioned exposure apparatus, developing the substrate (photosensitive agent), and processing the developed substrate in other well-known processing steps. Other well-known steps include etching, resist stripping, dicing, bonding, packaging, and the like. This manufacturing method makes it possible to manufacture an article of higher quality than before.

Claims

1. a first measurement unit including a detection unit that acquires an image signal of a mark on a substrate using an alignment optical system, and an image processing unit that processes the image signal of the mark acquired by the detection unit to measure the position of the mark; a second measurement unit whose relative position with respect to the first measurement unit is fixed and which measures a surface position of the substrate; a control unit that controls a position of the substrate based on the position of the mark measured by the first measurement unit, and controls to form a pattern on the substrate; The control unit is controlling the first measurement unit to start acquiring an image signal of the mark by the first measurement unit even when the surface position of the substrate is not within a focal depth of the alignment optical system; A pattern forming apparatus characterized in that, while acquiring an image signal of the mark, focus control is performed to adjust the surface position of the substrate so that the surface position of the substrate is included within the focal depth of the alignment optical system, based on the measurement result of the surface position of the substrate by the second measurement unit.

2. a projection optical system for projecting light from a pattern of an original onto the substrate; 2. The pattern forming apparatus according to claim 1, wherein the control unit aligns the substrate in a plane perpendicular to an optical axis of the projection optical system based on the position of the mark measured by the first measurement unit.

3. The control unit, while acquiring an image signal of the mark for aligning the substrate, 3. The pattern forming apparatus according to claim 2, wherein the focus control is performed at least twice.

4. The pattern forming device according to claim 2, characterized in that the control unit measures the surface position of the substrate by the second measurement unit at the timing of starting to acquire an image signal of the mark for aligning the substrate, and acquires an image signal of the mark while moving the measured surface position of the substrate toward a focal position of the alignment optical system.

5. The pattern forming apparatus according to claim 1 , wherein the first measurement unit has an image pickup element for picking up an image of the mark.

6. 6. The pattern forming apparatus according to claim 5, wherein the first measurement unit performs a pattern matching process or an edge detection process to measure the position of the mark.

7. The substrate further includes a holder for holding the substrate. 2 . The pattern forming apparatus according to claim 1 , wherein the control unit performs pre-alignment to correct a positional deviation of the substrate with respect to the holding unit based on the position of the mark.

8. 8. The pattern forming apparatus according to claim 7, wherein the control unit performs fine alignment after the pre-alignment to correct a positional deviation of the substrate with respect to the holding unit with higher accuracy than the pre-alignment.

9. 2. The pattern formation apparatus according to claim 1, wherein a part of an optical system included in the first measurement unit and a part of an optical system included in the second measurement unit are common to each other.

10. The pattern forming device as described in claim 1, characterized in that the focus control is performed multiple times while the detection unit detects the image signal once.

11. forming a pattern on a substrate using the pattern forming apparatus according to any one of claims 1 to 10; a step of processing the substrate on which the pattern has been formed in the step; A method for producing an article, comprising:

Images