Device and method for measuring thickness of workpiece and lithographic apparatus

Abstract

The invention relates to a device and a method for measuring the thickness of a workpiece, and lithographic equipment. The apparatus for measuring the thickness of a workpiece according to the present disclosure may comprise: a body; a light emitter; a light receiver; the guide rod moves up and down relative to the body, the first end of the guide rod makes contact with a workpiece, a reflecting mirror is arranged at the second end of the guide rod, and the light emitter and the light receiver are arranged in the mode that light emitted by the light emitter is reflected by the reflecting mirror and then received by the light receiver at the first position of the light receiver. And wherein the first position depends on the initialization receiving position and the workpiece thickness. The device for measuring the thickness of the workpiece determines the thickness of the workpiece based on the distance between the first position where the light receiver receives the light and the initialization receiving position. According to the device for measuring the thickness of the workpiece, the thickness of the workpiece is converted into the physical stroke of the guide rod, and therefore the device can be suitable for measuring the thicknesses of various types of workpieces.

Description

Technical Field

[0001] The present application relates to the field of industrial measurement, and in particular to a device, method and lithography equipment for measuring the thickness of a workpiece. Background Art

[0002] In the field of industrial manufacturing, accurate measurement of the thickness of the workpiece to be processed is crucial to ensure the accurate execution of subsequent processing steps. Especially in the manufacturing process of semiconductor devices, lithography equipment needs to accurately measure the thickness of the workpiece to be processed (for example, wafers) to achieve accurate exposure and development. The main function of lithography equipment is to use optical projection technology to project patterns onto photosensitive materials to form tiny patterns or layers, which mainly includes the following steps: mask preparation, silicon wafer coating, alignment exposure and development. Before these steps, it is essential to accurately measure the thickness of the wafer to ensure the accuracy of the exposure and development process.

[0003] Therefore, there is an urgent need for a measuring device that can accurately measure the thickness of a workpiece to provide reliable thickness data for subsequent processing. Summary of the invention

[0004] To overcome one or more of the disadvantages of the prior art, the present disclosure provides an apparatus, a method and a lithography apparatus for measuring the thickness of a workpiece.

[0005] In a first aspect, the present disclosure provides a device for measuring the thickness of a workpiece. The device may include: a body; a light transmitter; a light receiver; and a guide rod that moves up and down relative to the body, wherein a first end of the guide rod contacts the workpiece and a reflector is provided on a second end of the guide rod, wherein the light transmitter and the light receiver are arranged so that light emitted by the light transmitter is reflected by the reflector and received by the light receiver at a first position of the light receiver, and wherein the first position depends on an initialization receiving position and the thickness of the workpiece.

[0006] According to one embodiment of the present disclosure, optionally, the light emitter may be located at a first portion of the side wall of the body, the light receiver may be located at a second portion of the side wall of the body, and the guide rod may be located at the center of the body.

[0007] According to one embodiment of the present disclosure, optionally, the initialization receiving position may be a position where the light emitted by the light emitter is received by the light receiver after being reflected by the reflector when the guide rod is directly pressed against the upper surface of the workbench.

[0008] According to one embodiment of the present disclosure, optionally, the device may further include: a first guide sleeve fixed on the side wall of the main body; a second guide sleeve fixed on the side wall of the main body and located below the first guide sleeve, wherein the guide rod passes through the first guide sleeve and the second guide sleeve and can move up and down relative to the first guide sleeve and the second guide sleeve; a baffle fixed on the guide rod; a telescopic part, wherein the first end of the telescopic part is fixed to the first guide sleeve and the second end of the telescopic part is fixed to the baffle, and the guide rod passes through the telescopic part; and an electromagnet located above the baffle, wherein the electromagnet attracts the baffle when energized so that the baffle moves upward with the guide rod, and when the electromagnet is de-energized, the guide rod presses against the upper surface of the workpiece under the action of the telescopic part.

[0009] According to one embodiment of the present disclosure, optionally, the device may further include: a first seal fixed on the side wall of the main body; a second seal fixed on the side wall of the main body and located below the first seal, wherein the area in the main body sealed by the first seal and the second seal is filled with compressed dry air, wherein the guide rod passes through the first seal and the second seal and is capable of moving up and down relative to the first seal and the second seal; a piston that moves up and down relative to the main body and is located between the first seal and the second seal, wherein the guide rod passes through the piston and moves with the piston; a telescopic part, wherein the first end of the telescopic part is fixed to the piston and the second end of the telescopic part is fixed to the second seal, and the guide rod passes through the telescopic part; and an air inlet and an exhaust port provided between the first seal and the piston on the main body, wherein when the air inlet is opened and the exhaust port is closed, the piston drives the guide rod to move downward together so that the guide rod is pressed against the upper surface of the workpiece under the action of the telescopic part.

[0010] According to one embodiment of the present disclosure, optionally, the telescopic part may be a spring.

[0011] According to one embodiment of the present disclosure, optionally, the distance between the first position and the initialization receiving position can be measured by a laser displacement sensor, a grating ruler, or a capacitive pressure difference sensor.

[0012] According to one embodiment of the present disclosure, optionally, the device may further include: a rigid structure, wherein the rigid structure fixes the body so that the guide rod stands on the workbench and contacts the workbench, and wherein the movement range of the guide rod depends on the stroke of the telescopic part.

[0013] The device for measuring the thickness of a workpiece according to the present disclosure determines the thickness of the workpiece based on the distance between the first position and the initialization receiving position. The device for measuring the thickness of a workpiece according to the present disclosure converts the thickness of the workpiece into the physical stroke of the guide rod, so that it can be applied to measuring the thickness of various types of workpieces, especially to measuring the thickness of transparent workpieces.

[0014] In a second aspect, the present disclosure provides a lithographic apparatus comprising an apparatus as described above.

[0015] The lithographic apparatus according to the present disclosure adopts the measuring device as described above. The measuring device determines the thickness of the workpiece based on the distance between the first position and the initialization receiving position. That is, the measuring device converts the thickness of the workpiece into the physical stroke of the guide rod, so that it can be applied to measuring the thickness of various types of workpieces, especially to measuring the thickness of transparent workpieces.

[0016] In a third aspect, the present disclosure provides a method for measuring the thickness of a workpiece by the device as described above. The method may include: moving the workpiece above the workbench; driving the telescopic part so that the guide rod presses against the upper surface of the workpiece under the action of the telescopic part; and emitting light by the light emitter, wherein the light emitted by the light emitter is reflected by the reflector and received by the light receiver at a first position of the light receiver, and wherein the first position depends on the initialization receiving position and the thickness of the workpiece.

[0017] According to one embodiment of the present disclosure, optionally, the method may further include: driving the telescopic part so that the guide rod is pressed against the upper surface of the workbench under the action of the telescopic part; and emitting light from the light transmitter, wherein the position where the light emitted by the light transmitter is received by the light receiver after being reflected by the reflector is the initialization receiving position.

[0018] The method for measuring the thickness of a workpiece according to the present disclosure determines the thickness of the workpiece based on the distance between the first position and the initialization receiving position. The method for measuring the thickness of a workpiece according to the present disclosure converts the thickness of the workpiece into the physical stroke of the guide rod, and is suitable for measuring the thickness of various types of workpieces, especially for measuring the thickness of transparent workpieces.

[0019] These and other features and advantages will become apparent by reading the following detailed description and by reference to the associated drawings.It is to be understood that the foregoing general description and the following detailed description are illustrative only and are not restrictive of the aspects of what is claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to understand in detail the manner in which the above features of the present disclosure are used, the above briefly summarized contents may be described in more detail with reference to various embodiments, some of which are shown in the accompanying drawings. However, it should be noted that the accompanying drawings only show certain typical aspects of the present disclosure and should not be considered to limit its scope, as the description may allow for other equally effective aspects.

[0021] Figure 1 An example of an apparatus for measuring the thickness of a workpiece is explained.

[0022] Figure 2 A schematic diagram illustrating a first apparatus for measuring the thickness of a workpiece according to an embodiment of the present disclosure is illustrated.

[0023] Figure 3 A schematic diagram illustrating initialization of a first device according to an embodiment of the present disclosure.

[0024] Figure 4 A schematic diagram illustrating a second apparatus for measuring the thickness of a workpiece according to an embodiment of the present disclosure is illustrated.

[0025] Figure 5 A flow chart of a method for measuring a thickness of a workpiece by a first device or a second device according to an embodiment of the present disclosure is illustrated.

[0026] Figure 6 A schematic diagram for deriving the thickness of a workpiece according to an embodiment of the present disclosure is described.

[0027] Figure 7 A schematic structural diagram of a lithography device including an apparatus for measuring the thickness of a workpiece according to an embodiment of the present disclosure is described. DETAILED DESCRIPTION

[0028] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the described embodiments. However, it will be apparent to those skilled in the art that the described embodiments may be practiced without some or all of these specific details. In other embodiments, well-known structures or processing steps are not described in detail to avoid unnecessarily obscuring the concepts of the present disclosure.

[0029] In the description of the embodiments of the present disclosure, it should be noted that, unless otherwise specified, the term "plurality" means more than two; the term "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone; the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship. In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present disclosure belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure; the terms "including" and "having" in the specification and claims of the present disclosure and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0031] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present disclosure. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0032] As used herein, the terms "docking", "coupling", "connecting" or "connecting" mean connecting directly to or connecting through one or more intervening media or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure can be understood as the specific circumstances. Moreover, in the following description and for the purpose of explanation, specific nomenclature is set forth to provide a thorough understanding of the various embodiments of the present disclosure. However, it will be apparent to those skilled in the art that the exemplary embodiments can be practiced without these specific details.

[0033] In the industrial manufacturing process, it is generally required to accurately measure the thickness of the workpiece to be processed for the accurate execution of subsequent processing steps. However, there are many kinds of workpiece materials, and some measuring devices can only measure workpieces of certain materials, but cannot measure workpieces of specific materials (for example, transparent materials). Especially in the manufacturing process of semiconductor devices, photolithography equipment needs to accurately measure the thickness of the workpiece to be processed (for example, wafers) to achieve accurate exposure and development. The main function of photolithography equipment is to use optical projection technology to project patterns onto photosensitive materials to form tiny patterns or layers, mainly including the following steps: mask preparation, silicon wafer coating, alignment exposure and development. Before these steps, it is essential to accurately measure the thickness of the wafer to ensure the accuracy of the exposure and development process. At present, optical sensors are generally used to achieve the measurement of workpiece thickness.

[0034] Figure 1 An example of an apparatus 100 for measuring the thickness of a workpiece is illustrated. Figure 1As shown, the light emitter 105 first emits a beam of light to the workbench 120 and then reflects to the position point A on the light receiver 110 via the upper surface of the workbench 120. After the workpiece 115 is placed on the workbench 120, the light emitter 105 emits another beam of light to the workpiece 115 and then reflects to the position point B on the light receiver 110 via the upper surface of the workpiece 115. The thickness of the workpiece can be derived based on the distance between the position point A and the position point B. However, such a method is not suitable for measuring the thickness of a transparent workpiece. In the actual measurement process, for a transparent workpiece, the light emitted by the light emitter 105 will be reflected to the light receiver 110 via the upper surface and the lower surface of the transparent workpiece, respectively, and the light reflected to the light receiver 110 from the lower surface interferes with the determination of the thickness of the workpiece. Only by filtering out the light reflected to the light receiver 110 via the lower surface can the thickness of the workpiece 115 be accurately determined, and this may require the introduction of a large number of algorithms for calculation.

[0035] Therefore, there is an urgent need for a measuring device that can accurately measure the thickness of various types of workpieces (e.g., transparent workpieces). The present disclosure proposes a device for measuring the thickness of a workpiece. The measuring device according to the present disclosure can be applied to measure the thickness of various types of workpieces (e.g., transparent workpieces) without introducing complex algorithms. The device for measuring the thickness of a workpiece will be specifically described below in conjunction with the accompanying drawings and some embodiments will be listed for more specific description.

[0036] Figure 2 1 is a schematic diagram illustrating a first device 200 for measuring the thickness of a workpiece according to an embodiment of the present disclosure. Figure 2 As shown, the first device 200 may include a body 205. In one example, the body 205 may be a cylindrical body, a cuboid, or a cube of other regular shapes. Figure 2 As shown, the first device 200 may further include a light emitter 210 and a light receiver 215. For example, the light emitter 210 and the light receiver 215 may include, but are not limited to: a laser emitter and a laser receiver. In one example, the light emitter 210 is located on a first portion of the side wall of the body 205, and the light receiver 215 is located on a second portion of the side wall of the body 205. In some cases, the first portion may be opposite to the second portion. Figure 2As shown, the first device 200 may further include a guide rod 220 that moves up and down relative to the body 205, wherein the first end of the guide rod 220 contacts the workpiece 255 (for example, when the workpiece 255 is placed on the workbench 250) or the workbench 250 (for example, when the first device is initialized, that is, when the workpiece 255 is not placed on the workbench 250) and a reflector 225 is provided on the second end of the guide rod 220. In some cases, the guide rod 220 may be located at the center of the body 205. In some cases, the light emitter 210 and the light receiver 215 may be arranged so that the light emitted by the light emitter 210 is reflected by the reflector 225 and received by the light receiver 215 at a first position of the light receiver, wherein the first position depends on the initialization receiving position and the thickness of the workpiece 255. For example, the initialization receiving position may be a position where the light emitted by the light emitter 210 is received by the light receiver 215 after being reflected by the reflector 225 when the guide rod 220 directly presses against the upper surface of the workbench 250.

[0037] In one embodiment, Figure 2 As shown, the first device 200 may optionally include a first guide sleeve 235-1 fixed to the side wall of the body 205 and a second guide sleeve 235-2 fixed to the side wall of the body 205 and located below the first guide sleeve 235-1. In one example, the guide rod 220 passes through the first guide sleeve 235-1 and the second guide sleeve 235-2 and can move up and down relative to the first guide sleeve 235-1 and the second guide sleeve 235-2. Figure 2 As shown, the first device 200 may optionally include a baffle 240 fixed to the guide rod 220. In some cases, the baffle 240 may be made of a material that can be attracted by an electromagnet, such as but not limited to iron, steel, nickel, alloy, etc. Figure 2 As shown, the first device 200 may optionally include a telescopic portion 230. For example, the telescopic portion 230 may include, but is not limited to: a spring member. In one example, a first end of the telescopic portion 230 is fixed to the first guide sleeve 235-1 and a second end of the telescopic portion 230 is fixed to the baffle 240, and the guide rod 220 passes through the telescopic portion 230. Figure 2 As shown, the first device 200 may optionally include an electromagnet 245 located above the baffle 240. In one example, when the electromagnet 245 is powered on, it attracts the baffle 240 so that the baffle 240 moves upward with the guide rod 220, and the workpiece can be moved above the workbench 250. In one example, the electromagnet 245 is then powered off, and the guide rod 220 is pressed against the upper surface of the workpiece 255 under the action of the telescopic part 230, and the light emitter 210 emits light. In this case, the end of the guide rod 220 is a first distance away from the upper surface of the workpiece 255. Accordingly, the light emitted by the light emitter 210 is received at a first position (e.g., position point B) of the light receiver 215 after being reflected by the reflector 225.

[0038] In some cases, the first device 200 can be initialized before measuring. Figure 3 The schematic diagram of initializing the first device 200 according to an embodiment of the present disclosure is explained. Initializing the first device 200 may include: when no workpiece 255 is placed on the workbench 250, the electromagnet 245 is turned off, so that the guide rod 220 is pressed against the upper surface of the workbench 250 under the action of the telescopic part 230, such as Figure 3 As shown. The light emitter 210 may then emit light. In this case, the light emitted by the light emitter 210 is reflected by the reflector 225 and then received at the initialization receiving position (e.g., position point A) of the light receiver 215. For example, the first device 200 may be initialized before the formal measurement and record the initialization receiving position (e.g., position point A) where the light receiver 215 receives light during initialization, and then calculate the thickness of the workpiece based on the initialization receiving position during each formal measurement. In some cases, the first device 200 may be initialized before each formal measurement and compare the initialization receiving position where the light receiver 215 receives light during initialization with the first position where the light receiver 215 receives light during the formal measurement to determine the thickness of the workpiece based on the initialization receiving position and the first position. For example, the distance between the first position and the initialization receiving position may be measured by a laser displacement sensor, a grating ruler, a capacitive pressure difference sensor, and the like. The following will be combined with Figure 5 The calculation process of determining the thickness of the workpiece based on the initialization receiving position and the first position is described.

[0039] In one embodiment, the first device 200 may optionally include a rigid structure ( Figure 2 200). In one example, the rigid structure can fix the body 205 so that the guide rod 220 stands on the workbench 250 and contacts the upper surface of the workbench 250. In one example, the movement range of the guide rod 220 can depend on the stroke of the telescopic part 230. Preferably, the rigid structure can fix the body so that the guide rod 220 stands on the workbench 250 and contacts the workbench 250 when the telescopic part is in a natural state (e.g., not stretched and not compressed). In one example, the range in which the light receiver 215 can receive light can depend on the stroke of the guide rod 220.

[0040] The first device for measuring the thickness of a workpiece according to the present disclosure determines the thickness of the workpiece based on the distance between the first position and the initialization receiving position. The device for measuring the thickness of a workpiece according to the present disclosure converts the thickness of the workpiece into the physical stroke of the guide rod, so that it can be applicable to measuring the thickness of various types of workpieces, especially applicable to measuring the thickness of transparent workpieces.

[0041] Figure 41 is a schematic diagram illustrating a second device 400 for measuring the thickness of a workpiece according to an embodiment of the present disclosure. Figure 4 As shown, the second device 400 may include a body 405. In one example, the body 405 may be a cylindrical body, a cuboid, or other regularly shaped cubes. Figure 4 As shown, the second device 400 may further include a light transmitter 410 and a light receiver 415. For example, the light transmitter 410 and the light receiver 415 may include, but are not limited to: a laser transmitter and a laser receiver. In one example, the light transmitter 410 is located on a first portion of the side wall of the body 405, and the light receiver 415 is located on a second portion of the side wall of the body 405. In some cases, the first portion may be opposite to the second portion. Figure 4 As shown, the second device 400 may further include a guide rod 420 that moves up and down relative to the body 405, wherein a first end of the guide rod 420 contacts the workpiece 455 (for example, when the workpiece 455 is placed on the workbench 450) or the workbench 450 (for example, when the first device is initialized, i.e., when no workpiece 455 is placed on the workbench 450) and a reflector 425 is provided on the second end of the guide rod 420.

[0042] In some cases, the guide rod 420 may be located at the center of the body 405. In some cases, the light emitter 410 and the light receiver 415 may be arranged so that the light emitted by the light emitter 410 is received by the light receiver 415 at a first position of the light receiver after being reflected by the reflector 425, wherein the first position depends on the initial receiving position and the thickness of the workpiece 455. For example, the initial receiving position may be a position where the light emitted by the light emitter 410 is received by the light receiver 415 after being reflected by the reflector 425 when the guide rod 420 is directly pressed against the upper surface of the workbench 450.

[0043] In one embodiment, Figure 4 As shown, the second device 400 may optionally include a first seal 435-1 fixed to the side wall of the body 405 and a second seal 435-2 fixed to the side wall of the body 405 and located below the first seal 435-1. In one example, the area sealed by the first seal 435-1 and the second seal 435-2 in the body 405 may be filled with compressed dry air. In this example, the guide rod 420 may pass through the first seal 435-1 and the second seal 435-2 and can move up and down relative to the first seal 435-1 and the second seal 435-2. Figure 4 As shown, the second device 400 may optionally include a piston 440 that moves up and down relative to the body 405 and is located between the first seal 435-1 and the second seal 435-2. In one example, the guide rod 420 passes through the piston 440 and moves with the piston 440. Figure 4As shown, the second device 400 may optionally include a telescopic portion 430. For example, the telescopic portion 430 may include, but is not limited to, a spring member. In one example, a first end of the telescopic portion 430 may be fixed to the piston 440 and a second end of the telescopic portion 430 may be fixed to the second sealing member 435-2, and the guide rod 420 passes through the telescopic portion 430. Figure 4 As shown, the second device 400 may optionally include an air inlet 445-1 and an exhaust port 445-2 disposed between the first seal 435-1 and the piston 440 on the body 405. In one example, when the air inlet 445-1 is closed and the exhaust port 445-2 is opened, the piston 440 drives the guide rod 420 to move upward together, and the workpiece can be moved above the workbench 450. In one example, when the air inlet 445-1 is opened and the exhaust port 445-2 is closed, the piston 440 drives the guide rod 420 to move downward together so that the guide rod 420 is pressed against the upper surface of the workpiece 455 under the action of the telescopic portion 430, and the light emitter 410 emits light. In this case, the end of the guide rod 420 is a first distance away from the upper surface of the workpiece 455. Accordingly, the light emitted by the light emitter 410 is received at a first position (e.g., position point B) of the light receiver 415 after being reflected by the reflector 425.

[0044] In some cases, the second device 400 may be initialized before measurement. Similar to the initialization of the first device 200, the initialization of the second device 400 may include: when no workpiece 455 is placed on the workbench 450, the air inlet 445-1 is opened and the exhaust port 445-2 is closed, so that the piston 440 drives the guide rod 420 to move downward together so that the guide rod 420 is pressed against the upper surface of the workbench 450 under the action of the telescopic portion 430, as shown in FIG. Figure 5 As shown. The light emitter 410 may then emit light. In this case, the light emitted by the light emitter 410 is reflected by the reflector 425 and then received at the initialization receiving position (e.g., position point A) of the light receiver 415. For example, the second device 400 may be initialized before the formal measurement and record the initialization receiving position (e.g., position point A) where the light receiver 415 receives light during initialization, and then calculate the thickness of the workpiece based on the initialization receiving position during each formal measurement. In some cases, the second device 400 may be initialized before each formal measurement and compare the initialization receiving position where the light receiver 415 receives light during initialization with the first position where the light receiver 415 receives light during the formal measurement to determine the thickness of the workpiece based on the initialization receiving position and the first position. For example, the distance between the first position and the initialization receiving position may be measured by a laser displacement sensor, a grating ruler, a capacitive pressure difference sensor, and the like. The following will be combined with Figure 5 The calculation process of determining the thickness of the workpiece based on the initialization receiving position and the first position is described.

[0045] In one embodiment, the second device 400 may optionally include a rigid structure ( Figure 4 400). In one example, the rigid structure can fix the body 405 so that the guide rod 420 stands on the workbench 450 and contacts the upper surface of the workbench 450. In one example, the movement range of the guide rod 420 can depend on the stroke of the telescopic part 430. Preferably, the rigid structure can fix the body so that the guide rod 420 stands on the workbench 450 and contacts the workbench 450 when the telescopic part is in a natural state (e.g., not stretched and not compressed). In one example, the range in which the light receiver 415 can receive light can depend on the stroke of the guide rod 420.

[0046] The second device 400 for measuring the thickness of a workpiece according to the present disclosure determines the thickness of the workpiece based on the distance between the first position and the initialization receiving position. The device for measuring the thickness of a workpiece according to the present disclosure converts the thickness of the workpiece into the physical stroke of the guide rod, so that it can be applicable to measuring the thickness of various types of workpieces, especially to measuring the thickness of transparent workpieces.

[0047] Figure 5 A flow chart of a method 500 for measuring the thickness of a workpiece by the first device 200 or the second device 400 according to an embodiment of the present disclosure is illustrated. The method 500 may include the following steps.

[0048] At step 505, a workpiece may be moved over a work table.

[0049] In step 510 , the telescopic portion may be driven so that the guide rod is pressed against the upper surface of the workpiece under the action of the telescopic portion.

[0050] In step 515 , the light emitter may emit light, wherein the light emitted by the light emitter is reflected by the reflector and then received by the light receiver at a first position of the light receiver, wherein the first position depends on the initialization receiving position and the thickness of the workpiece.

[0051] In one example, method 500 may optionally include: driving the telescopic part so that the guide rod is pressed against the upper surface of the workbench under the action of the telescopic part; and emitting light from the light emitter, wherein the position where the light emitted by the light emitter is received by the light receiver after being reflected by the reflector is the initialization receiving position.

[0052] Those skilled in the art will appreciate that Figure 5 The method 500 is described as an example only, and one or more steps in the method 500 may be omitted or repeated without departing from the scope of the present disclosure.

[0053] The method for measuring the thickness of a workpiece according to the present disclosure determines the thickness of the workpiece based on the distance between the first position and the initialization receiving position 0. The method for measuring the thickness of a workpiece according to the present disclosure converts the thickness of the workpiece into the physical stroke of the guide rod, and is suitable for measuring the thickness of various types of workpieces, especially for measuring the thickness of transparent workpieces.

[0054] Figure 6 The schematic diagram for determining the thickness of a workpiece according to an embodiment of the present disclosure is explained. The two emitted lights and reflected lights can be simplified as follows: Figure 6 As shown. Given that triangle △ABC is similar to triangle △MON and AC=PN=2×MN, it can be deduced that AB=2×MO, that is, the workpiece thickness t (i.e. Δh) = Δd / 2, where Δd is the distance between the positions A and B where the two reflected lights are received. For example, assuming that the distance between the positions A and B is 200μm, the workpiece thickness is 100μm.

[0055] Figure 7 The structure diagram of the lithography apparatus 700 including the first device 200 or the second device 400 for measuring the thickness of the workpiece according to an embodiment of the present disclosure is illustrated. Figure 7 As shown, the lithographic apparatus 700 may include Figure 2 The first device 200 for measuring the thickness of a workpiece shown in FIG. Figure 4 A second device 400 for measuring the thickness of a workpiece is shown in FIG.

[0056] The lithography apparatus 700 according to the present disclosure uses the first device 200 or the second device 400 as described above. The first device 200 or the second device 400 determines the thickness of the workpiece based on the distance between the first position where the light receiver receives light and the initialization receiving position where the light receiver receives light when the first device 200 or the second device 400 is initialized. That is, the first device 200 or the second device 400 converts the thickness of the workpiece into the physical stroke of the guide rod, so that it can be applicable to measuring the thickness of various types of workpieces, especially applicable to measuring the thickness of transparent workpieces.

[0057] Those skilled in the art will appreciate that Figure 7 This is provided by way of example only and is not intended to be limiting.

[0058] The "range" disclosed herein is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. In this application, unless otherwise specified, the numerical range "ab" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers.

[0059] In this application, unless otherwise specified, all embodiments and preferred embodiments mentioned herein can be combined with each other to form a new technical solution.

[0060] In the present application, unless otherwise specified, all technical features and preferred features mentioned herein can be combined with each other to form new technical solutions. Although the present application has been described with reference to optional embodiments, various improvements can be made thereto and components thereof can be replaced with equivalents without departing from the scope of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any manner. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A device for measuring the thickness of a workpiece, comprising: ontology; Light transmitter; Optical receiver; as well as A guide rod that moves up and down relative to the body, wherein the first end of the guide rod is in contact with the workpiece and a reflector is provided on the second end of the guide rod, wherein the light emitter and the light receiver are arranged so that the light emitted by the light emitter is received by the light receiver at a first position of the light receiver after being reflected by the reflector, and wherein the first position depends on an initialization receiving position and a thickness of the workpiece.

2. The device according to claim 1, characterized in that The light emitter is located at a first portion of the side wall of the body, the light receiver is located at a second portion of the side wall of the body, and the guide rod is located at the center of the body.

3. The device according to claim 1, characterized in that The initialization receiving position is a position where the light emitted by the light transmitter is received by the light receiver after being reflected by the reflector when the guide rod is directly pressed against the upper surface of the workbench.

4. The device according to claim 1, characterized in that Further including: A first guide sleeve fixed to the side wall of the body; A second guide sleeve fixed to the side wall of the body and located below the first guide sleeve, wherein the guide rod passes through the first guide sleeve and the second guide sleeve and can move up and down relative to the first guide sleeve and the second guide sleeve; a baffle fixed on the guide rod; a telescopic portion, wherein a first end of the telescopic portion is fixed to the first guide sleeve and a second end of the telescopic portion is fixed to the baffle, and the guide rod passes through the telescopic portion; as well as An electromagnet is located above the baffle, wherein the electromagnet attracts the baffle when energized so that the baffle moves upward with the guide rod, and when the electromagnet is de-energized, the guide rod presses against the upper surface of the workpiece under the action of the telescopic portion.

5. The device according to claim 1, characterized in that Further including: a first sealing member fixed to the side wall of the body; a second seal fixed to the side wall of the body and located below the first seal, wherein the area of ​​the body sealed by the first seal and the second seal is filled with compressed dry air, wherein the guide rod passes through the first seal and the second seal and can move up and down relative to the first seal and the second seal; a piston that moves up and down relative to the body and is located between the first seal and the second seal, wherein the guide rod passes through the piston and moves with the piston; a telescopic portion, wherein a first end of the telescopic portion is fixed to the piston and a second end of the telescopic portion is fixed to the second sealing member, and the guide rod passes through the telescopic portion; as well as An air inlet and an air exhaust port are provided between the first sealing member and the piston on the main body, wherein when the air inlet is opened and the air exhaust port is closed, the piston drives the guide rod to move downward together so that the guide rod is pressed against the upper surface of the workpiece under the action of the telescopic portion.

6. The device according to any one of claims 4 or 5, characterized in that: The telescopic part is a spring; or The distance between the first position and the initialization receiving position is measured by a laser displacement sensor, a grating ruler, and a capacitive pressure difference sensor.

7. The device according to claim 6, characterized in that Further including: A rigid structure, wherein the rigid structure fixes the body so that the guide rod stands on and contacts the workbench, and wherein the movement range of the guide rod depends on the stroke of the telescopic portion.

8. A lithographic apparatus comprising the apparatus of any one of claims 1 to 7.

9. A method for measuring the thickness of a workpiece by the device according to any one of claims 1 to 7, comprising: Move the workpiece onto the workbench; Driving the telescopic part so that the guide rod is pressed against the upper surface of the workpiece under the action of the telescopic part; as well as The light emitter emits light, wherein the light emitted by the light emitter is received by the light receiver at a first position of the light receiver after being reflected by the reflector, and wherein the first position depends on an initialization receiving position and a thickness of the workpiece.

10. The method according to claim 9, characterized in that Further including: Driving the telescopic part so that the guide rod is pressed against the upper surface of the workbench under the action of the telescopic part; as well as The light emitter emits light, and the position where the light emitted by the light emitter is received by the light receiver after being reflected by the reflector is the initialization receiving position.

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