Motion stage system and lithographic apparatus

Abstract

This invention provides a motion stage system and a photolithography apparatus. The motion stage system includes a motion stage and a displacement measuring device connected to the motion stage. The displacement measuring device includes at least two gratings and a read head that cooperates with each grating. Each grating has a light-incident surface, and the light-incident surfaces of at least two of the gratings are non-parallel. Each grating extends along the surface of the motion stage. The displacement measuring device calculates the displacement of the motion stage in the length direction of each grating and the displacement in the normal direction of each grating, thereby calculating the positional change of the motion stage in more than three degrees of freedom. This motion stage system utilizes at least two gratings and corresponding read heads to measure the positional change of the motion stage in more than three degrees of freedom, which helps to improve the position measurement capability and modalities of the motion stage system. The photolithography apparatus includes the above-described motion stage system.

Description

Technical Field

[0001] This invention relates to the field of displacement measurement technology, and in particular to a motion stage system and photolithography equipment. Background Technology

[0002] As integrated circuits advance towards large-scale and high-integration, the requirements for the overlay accuracy of lithography machines are also increasing. In order to improve the overlay accuracy, it is necessary to improve the measurement accuracy when acquiring the position information of the workpiece stage and mask stage in each degree of freedom.

[0003] In traditional photolithography systems, interferometer measurement systems are used to acquire the positional information of the workpiece stage and mask stage in each degree of freedom. Interferometer measurement systems have high measurement accuracy, reaching the nanometer level. However, the measurement accuracy of current interferometer measurement systems has almost reached its limit. At the same time, the measurement accuracy is greatly affected by the surrounding environment, and the measurement repeatability is not high (even in a good environment, the difference in repeated measurements will exceed 1 nm). As a result, it is difficult to meet the requirements of further improving the overlay accuracy using traditional interferometer measurement systems.

[0004] Compared to interferometer measurement systems, grating ruler measurement systems have a shorter optical path, which is independent of the measurement range. Grating ruler measurement systems are insensitive to environmental influences, have high measurement stability, simple structure, and are easy to miniaturize, making them an important part of the nanoscale measurement field. In next-generation lithography systems, grating measurement systems are gradually replacing interferometer measurement systems.

[0005] Figure 1 This is an existing mask stage displacement measuring device. The mask stage displacement measuring device is used to measure the displacement of the mask stage, such as... Figure 1 As shown, the mask stage includes a mask stage chuck 800', which is used to hold and move a mask for forming a photolithographic pattern. The mask stage chuck 800' has two opposing sidewalls. In this mask stage displacement measuring device, two two-dimensional gratings (such as...) Figure 1 The sides of the first two-dimensional grating 201' and the second two-dimensional grating 202' shown are respectively bonded to two opposite sidewalls of the mask stage clamp 800'. Both the first two-dimensional grating 201' and the second two-dimensional grating 202' have a two-dimensional plane (called the incident surface) for setting two-dimensionally arranged diffraction units. The incident surfaces of the first two-dimensional grating 201' and the second two-dimensional grating 202' are essentially on the same plane (of the same height) as the mask surface 801 of the mask, and the incident surfaces of the first two-dimensional grating 201' and the second two-dimensional grating 202' face downwards (e.g., ...). Figure 1In the negative Z direction), a first reading head 101' and a second reading head 102' are respectively arranged directly below the light incident surfaces of the first two-dimensional grating 201' and the second two-dimensional grating 202'. The first reading head 101' and the first two-dimensional grating 201' cooperate to measure the mask stage chuck 800' along the X-axis and Y-axis (the Y-axis is perpendicular to the X-axis and Z-axis). Figure 1 The displacement (not shown) can be used to measure the displacement of the mask stage chuck 800' along the X and Y axes by using the second read head 102' and the second two-dimensional grating 202' in cooperation.

[0006] However, the above-mentioned mask stage displacement measuring device has the following problems: (1) Due to the relatively high difficulty and cost of processing two-dimensional gratings, the cost of the above-mentioned mask stage displacement measuring device is relatively high; (2) The two two-dimensional gratings and corresponding reading heads used in the mask stage displacement measuring device can only measure a limited number of degrees of freedom of the mask stage clamp 800' (maximum X, Y, R). Z Three degrees of freedom, R Z (3) Since the sides of the first two-dimensional grating 201' and the second two-dimensional grating 202' are respectively bonded to the two opposite sides of the mask stage clamp 800', the side of the mask stage clamp 800' extends out to a large extent, resulting in a lower mode of the mask stage (mainly referring to the mask stage clamp 800'). Summary of the Invention

[0007] To address the aforementioned problems in displacement measurement, this invention provides a motion stage system. Additionally, a photolithography apparatus including the aforementioned motion stage system is provided.

[0008] The present invention provides a motion stage system, the motion stage system including a motion stage and a displacement measuring device connected to the motion stage, the displacement measuring device including at least two gratings and a read head used in conjunction with each of the gratings; each grating has at least a plurality of diffraction units arranged in a one-dimensional manner and an incident surface coplanar with the plurality of diffraction units; wherein each of the gratings extends along the surface of the motion stage to form a one-dimensional dimension, and the incident surfaces of at least two of the gratings are non-parallel surfaces, the displacement measuring device calculates the displacement of the motion stage in the length direction of each of the gratings and the displacement in the normal direction of each of the gratings, and then calculates the positional change of the motion stage in more than three degrees of freedom.

[0009] Optionally, the motion table is located in a first orthogonal coordinate system, the origin O of the first orthogonal coordinate system is the motion center of the motion table, the first orthogonal coordinate system includes mutually orthogonal X-axis, Y-axis and Z-axis, the motion table has translational degrees of freedom along the X-axis, Y-axis and / or Z-axis respectively, and rotational degrees of freedom in the XZ plane, YZ plane and / or XY plane respectively.

[0010] Optionally, the displacement measuring device includes at least two one-dimensional gratings.

[0011] Optionally, the displacement measuring device includes a first one-dimensional grating, a second one-dimensional grating, a third one-dimensional grating, and a first reading head, a second reading head, and a third reading head used in conjunction with the first one-dimensional grating, the second one-dimensional grating, and the third one-dimensional grating, respectively; the length directions of the first one-dimensional grating, the second one-dimensional grating, and the third one-dimensional grating are all parallel to the Y-axis, the light incident surfaces of the first one-dimensional grating and the second one-dimensional grating are opposite to each other and both are perpendicular to the X-axis, and the light incident surface of the third one-dimensional grating is perpendicular to the Z-axis.

[0012] The displacement measuring device uses the first read head and the first one-dimensional grating to obtain a first displacement of the first one-dimensional grating along the Y-axis and a second displacement along the X-axis, uses the second read head and the second one-dimensional grating to obtain a third displacement of the second one-dimensional grating along the Y-axis and a fourth displacement along the X-axis, and uses the third read head and the third one-dimensional grating to obtain a fifth displacement of the third one-dimensional grating along the Y-axis and a sixth displacement along the Z-axis; the displacement of the motion stage along the X-axis is equal to the second displacement or the fourth displacement, the displacement along the Y-axis is equal to the first displacement, the third displacement, or the fifth displacement, and the displacement along the Z-axis is equal to the sixth displacement.

[0013] Optionally, the rotation amount R of the motion table in the XZ plane Y The amount of rotation R in the YZ plane X The amount of rotation R in the XY plane Z The following relationship must be satisfied:

[0014] R Y =d Z6 / L X , where d Z6 L is the sixth displacement. X The distance between the center point of the incident laser guided by the third read head on the incident surface of the third one-dimensional grating and the origin O in the X-axis direction;

[0015] R X =d Y5 / ΔZ, where d Y5 The fifth displacement is ΔZ, which is the distance along the Z-axis between the center point formed by the incident laser guided by the first read head on the incident surface of the first one-dimensional grating and the center point formed by the incident laser guided by the third read head on the incident surface of the third one-dimensional grating.

[0016] R Z =(d Y1 -d Y3 ) / ΔX, where d Y1 Let d be the first displacement. Y3 The third displacement is ΔX, which is the distance between the incident surfaces of the first one-dimensional grating and the second one-dimensional grating in the X-axis direction.

[0017] Optionally, the motion stage has a first sidewall and a second sidewall that are disposed opposite to each other and perpendicular to the X-axis. The first one-dimensional grating is attached to the first sidewall or formed by etching the first sidewall, and the second one-dimensional grating is attached to the second sidewall or formed by etching the second sidewall. The motion stage also has a lower surface that is perpendicular to the first sidewall and the second sidewall, and the third one-dimensional grating is attached to the lower surface or formed by etching the lower surface.

[0018] Optionally, the displacement measuring device includes a first one-dimensional grating, a second one-dimensional grating, a first reading head and a third reading head used in conjunction with the first one-dimensional grating, and a second reading head used in conjunction with the second one-dimensional grating; the displacement measuring device is located in a second orthogonal coordinate system, the second orthogonal coordinate system including mutually orthogonal X' axis, Y' axis and Z' axis and origin O', the Y' axis is set along the length direction of the first one-dimensional grating and the second one-dimensional grating, the Z' axis is perpendicular to the light incident surface of the first one-dimensional grating, the X' axis has an angle of less than 90 degrees with the normal direction of the second one-dimensional grating, and the first reading head and the third reading head have a first preset distance greater than zero along the direction of the X' axis; the first orthogonal coordinate system is obtained by projection transformation of the second orthogonal coordinate system.

[0019] Optionally, the incident surface of the second one-dimensional grating is perpendicular to the X' axis; the displacement measuring device uses the first read head and the first one-dimensional grating to obtain a first displacement of the first one-dimensional grating along the Y' axis and a second displacement along the Z' axis, uses the second read head and the second one-dimensional grating to obtain a third displacement of the second one-dimensional grating along the Y' axis and a fourth displacement along the X' axis, and uses the third read head and the first one-dimensional grating to obtain a fifth displacement of the first one-dimensional grating along the Y' axis and a sixth displacement along the Z' axis; the displacement of the motion stage along the X' axis is equal to the fourth displacement, the displacement along the Y' axis is equal to the first displacement, the third displacement, or the fifth displacement, and the displacement along the Z' axis is equal to the second displacement or the sixth displacement.

[0020] Optionally, the rotation amount R' of the motion table in the X'Z' plane Y Rotational amount R' in the Y'Z' plane X The amount of rotation R' in the X'Y' plane Z The following relationship must be satisfied:

[0021] R' Y =(d Z2 -d Z6 ) / ΔX', where d Z2 Let d be the second displacement. Z6 The sixth displacement is ΔX', and the first preset spacing is ΔX'.

[0022] R' X =d Y1 / D O'A , where d Y1 Let d be the first displacement. Y5 For the fifth displacement, D O'A The distance between the center point formed by the incident laser guided by the first read head on the incident surface of the first one-dimensional grating and the origin O';

[0023] R' Z =d Y3 / D O'B , where d Y3 For the third displacement, D O'B The distance between the center point formed by the incident laser guided by the second read head on the incident surface of the second one-dimensional grating and the origin O'.

[0024] Optionally, the motion stage has a first sidewall parallel to the light-incident surface of the first one-dimensional grating and a second sidewall parallel to the light-incident surface of the second one-dimensional grating; the length direction of the first one-dimensional grating is the same as the length direction of the first sidewall, and the first one-dimensional grating is attached to the first sidewall or formed by etching the first sidewall; the length direction of the second one-dimensional grating is the same as the length direction of the second sidewall, and the second one-dimensional grating is attached to the second sidewall or formed by etching the second sidewall.

[0025] Optionally, the first sidewall and the second sidewall are respectively connected to the lower surface of the motion table, and the angle between them and the lower surface of the motion table is obtuse. The first sidewall and the second sidewall are symmetrical about the Z-axis in the first orthogonal coordinate system.

[0026] The motion stage system of the present invention has the following technical effects: (1) The displacement measuring device of the motion stage system can measure the displacement of the motion stage in the length direction of each of the gratings and the displacement in the normal direction of each of the gratings, and then calculate the position change of the motion stage in more than three degrees of freedom. The measurement of the position change of the motion stage is more comprehensive, which can improve the measurement capability of the motion stage system for the position change of the motion stage; (2) Compared with the prior art, the two two-dimensional gratings extend from the side of the mask stage clamp, the gratings of the displacement measuring device extend along the surface of the motion stage, which helps to improve the modality of the motion stage system.

[0027] Another aspect of the present invention provides a photolithography apparatus, the photolithography apparatus including the above-described motion stage system, wherein the motion stage is a mask stage or a workpiece stage.

[0028] The lithography apparatus of the present invention includes the aforementioned motion stage system. Since the displacement measuring device of the motion stage system in the lithography apparatus utilizes at least two gratings and a read head used in conjunction with each of the gratings, it is possible to obtain the positional changes of the motion stage in more than three degrees of freedom, which helps to improve the lithography apparatus's ability to measure the positional changes of the motion stage and can improve the performance of the lithography apparatus. Attached Figure Description

[0029] Figure 1 This is an existing mask stage displacement measuring device.

[0030] Figure 2 This is a schematic diagram of the displacement measuring device according to Embodiment 1 of the present invention.

[0031] Figures 3a to 3f This is a schematic diagram showing different structures of the reverse echo element inside the reading head in the displacement measuring device of Embodiment 1 of the present invention.

[0032] Figure 4 This is a schematic diagram of the motion table system according to Embodiment 2 of the present invention.

[0033] Figure 5 for Figure 4 A cross-sectional schematic diagram of the motion table system in the XZ plane.

[0034] Figure 6 This is a system layout diagram of the motion table system according to Embodiment 2 of the present invention.

[0035] Figure 7 This is a schematic diagram of the motion table system according to Embodiment 3 of the present invention.

[0036] Figure 8 for Figure 7 A cross-sectional schematic diagram of the motion table system in the XZ plane.

[0037] Figure 9 This is a system layout diagram of the motion table system according to Embodiment 3 of the present invention. Detailed Implementation

[0038] The motion stage system and photolithography equipment proposed in this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of this invention will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of this invention.

[0039] It should be noted that the embodiments in this specification are described in a progressive manner. The focus of the later embodiments is to explain their differences from the earlier embodiments. The similarities and similarities between the various parts can be referred to each other. Moreover, combining the various embodiments can yield a more detailed technical solution.

[0040] Example 1

[0041] This embodiment mainly describes a specific structure of the displacement measuring device used in the motion table system of the present invention, and a method for obtaining the displacement of the grating (e.g., a one-dimensional grating) in the length direction and the displacement in the normal direction. Figure 2 This is a schematic diagram of the structure of a displacement measuring device according to an embodiment of the present invention. Figure 2 As shown, the displacement measuring device includes a one-dimensional grating 200 and a read head 100 used in conjunction with the one-dimensional grating 200. The one-dimensional grating has a plurality of diffraction units arranged in a one-dimensional manner and an incident surface coplanar with the plurality of diffraction units. The displacement measuring device emits incident laser light into the incident surface of the one-dimensional grating 200 through the read head 100, obtains corresponding feedback laser light, and processes the feedback laser light to obtain the distance along the length direction of the one-dimensional grating 200 (e.g., along the length direction of the one-dimensional grating). Figure 2(in the Y-axis) and along the normal direction of the one-dimensional grating (e.g.) Figure 2 The displacement along the X-axis is measured using a one-dimensional grating 200 and a read head 100, which enables two-dimensional measurement of the displacement of the one-dimensional grating 200.

[0042] In this embodiment, the displacement measuring device may further include a laser source, a detection unit, and a processing unit; the laser source is used to emit the incident laser to the read head 100; the read head 100 is used to receive and guide the incident laser so that the incident laser irradiates the one-dimensional grating 200, and after diffraction and / or reflection by the one-dimensional grating 200, the read head 100 outputs the feedback laser; the detection unit is used to detect the feedback laser and output the phase information of the interference signal of the feedback laser; the processing unit is used to receive the phase information of the interference signal of the feedback laser and calculate and process to obtain the displacement of the one-dimensional grating 200 along the X-axis and the Y-axis.

[0043] like Figure 2 As shown, the laser source (not shown in the figure) can emit a first incident beam 610 and a second incident beam 611 (i.e., the incident laser includes a first incident beam 610 and a second incident beam 611). The read head 100 receives and guides the first incident beam 610 and the second incident beam 611 to illuminate the one-dimensional grating 200 in parallel. After diffraction and / or reflection by the one-dimensional grating 200, the read head 100 outputs a first feedback laser 612 and a second feedback laser 613.

[0044] The read head 100 may include multiple retroreflection elements. The retroreflection elements can change the direction of the incident laser beam and output an outgoing laser beam with a direction opposite to that of the incident laser beam, and the outgoing laser beam is offset by a certain distance relative to the incident laser beam. Figures 3a to 3f This is a schematic diagram showing different structures of the retroreflective element inside the read head in one embodiment of the present invention. The retroreflective element can be a corner cube prism (…). Figure 3a ), right-angle prism ( Figure 3b ), cat's eye reflector ( Figure 3c ), Dove Prism ( Figure 3d ), hollow retroreflector ( Figure 3e ) or grating reflector ( Figure 3f ).

[0045] like Figure 2As shown, the process of the read head 100 outputting the first feedback laser 612 can be as follows: the first incident beam 610 and the second incident beam 611 are guided parallel by the read head 100 to illuminate different positions on the incident surface of the one-dimensional grating 200, and after diffraction by the one-dimensional grating 200, a first diffracted beam is generated; the second retroreflection element 111 receives the +m-order first diffracted beam (e.g., the +1-order first diffracted beam) of the first incident beam 610 and reflects it back to the one-dimensional grating 200, and after secondary diffraction by the one-dimensional grating 200, a +m-order second diffracted beam of the first incident beam 610 is generated; the first retroreflection element 110 receives... The -n-order first diffracted beam (e.g., the -1-order first diffracted beam) of the second incident beam 611 is received and reflected back onto the one-dimensional grating 200. After secondary diffraction by the one-dimensional grating 200, the -n-order second diffracted beam of the second incident beam 611 is generated. By setting the first and second retroreflection elements 110 and 111 in appropriate positions, the +m-order second diffracted beam of the first incident beam 610 and the -n-order second diffracted beam of the second incident beam 611 at least partially overlap, and the overlapping part has the same emission direction, forming a first feedback laser 612, where m and n are diffraction orders, such as ±1, ±2, or ±3. The phase change of the interference signal of the first feedback laser 612 reflects the displacement of the one-dimensional grating 200 along the Y-axis.

[0046] The process of the read head 100 outputting the second feedback laser 613 can be as follows: The first incident beam 610 and the second incident beam 611 are guided parallel by the read head 100 to illuminate different positions of the one-dimensional grating 200, and after diffraction by the one-dimensional grating 200, they both generate a first-order diffracted beam; the second retroreflection element 111 receives the +n-order first-order diffracted beam (e.g., +1-order) of the first incident beam 610 and reflects it back to the one-dimensional grating 200. After a first reflection by the one-dimensional grating 200, it enters the first retroreflection element 110, is reflected back to the one-dimensional grating 200 by the first retroreflection element 110, and then undergoes a second reflection by the one-dimensional grating 200 to generate a second-reflected beam of the first incident beam 610. A second incident beam 610 is reflected twice and then incident on a reflective element 130. A second incident beam 611 is diffracted by the one-dimensional grating 200 to produce a +m-order first-order diffracted beam (e.g., +1 order). This +m-order first-order diffracted beam then incident on the reflective element 130. By positioning the first and second retroreflective elements 110 and 111 appropriately, the second incident beam 610 and the +m-order first-order diffracted beam 611 at least partially overlap and incident on the reflective element 130, with the overlapping portion exiting in the same direction. The reflection by the reflective element 130 forms a second feedback laser 613, where m and n are diffraction orders, such as ±1, ±2, or ±3. The phase change of the interference signal of the second feedback laser 613 reflects the displacement of the one-dimensional grating 200 along the X-axis.

[0047] Continue to refer to Figure 2 The read head 100 may further include at least one beam angle controller. Specifically, the read head 100 may include a first angle controller 700 and a second angle controller 701. The first angle controller 700 may be disposed in the incident optical path of the first incident beam 610 and is used to adjust the incident angle of the first incident beam 610 relative to the normal direction of the one-dimensional grating 200. The second angle controller 701 may be disposed between the retroreflection element and the optical path of the one-dimensional grating 200 and is used to adjust the angle of the incident beam or the outgoing beam of the retroreflection element.

[0048] In this embodiment, the detection unit may include multiple collectors. For example... Figure 2As shown, the detection unit includes a first collector 410 and a second collector 411. As an example, the first collector 410 acquires the phase of the interference signal of the first feedback laser 612 and transmits the acquired phase information to the processing unit 500 via the first transmission fiber 430; the second collector 411 acquires the phase of the interference signal of the second feedback laser 613 and transmits the acquired phase information to the processing unit 500 via the second transmission fiber 431. The processing unit 500 can calculate the phase change of the first feedback laser 612 and the second feedback laser 613 respectively, and calculate the displacement of the one-dimensional grating 200 along the X-axis and the Y-axis respectively according to the set formulas.

[0049] Specifically, when m = n, the phase change of the interference signal of the first feedback laser 612 and the displacement of the one-dimensional grating 200 along the Y-axis satisfy the following relationship:

[0050]

[0051] in, Δy is the phase change of the interference signal of the first feedback laser 612, p is the spacing between two adjacent diffraction units of the one-dimensional grating 200 along the Y-axis, Δy is the displacement of the one-dimensional grating 200 along the Y-axis, and m is the diffraction order.

[0052] When m = n, the phase change of the interference signal of the second feedback laser 613 and the displacement of the one-dimensional grating 200 in the X-axis satisfy the following relationship:

[0053]

[0054] in, λ is the phase change of the interference signal of the second feedback laser 612, λ is the wavelength of the incident laser, θ is the m-th order diffraction angle of the first diffraction after the incident laser (i.e., the first incident beam 610 and the second incident beam 211) contacts the one-dimensional grating, Δx is the displacement of the one-dimensional grating in the X-axis, and m is the diffraction order.

[0055] When the displacement measuring device performs displacement measurement, the read head 100 can output two corresponding second feedback laser beams. After processing by the detection unit and the processing unit, two displacements of the first one-dimensional grating 201 in the X-axis direction can be obtained. If the two displacements are equal, the measurement optical path between the one-dimensional grating 200 and the read head 100 is less affected by the environment, the measurement accuracy is relatively high, and the read head 100 does not need compensation or correction. If the two displacements are not equal, the influence of the environment on the measurement optical path can be compensated, and the read head 100 can also be compensated or corrected.

[0056] In another embodiment, the read head 100 may employ a high-magnification subdivision structure. The read head 100 in the displacement measuring device may include a first retroreflective element, a second retroreflective element, a third retroreflective element, a fourth retroreflective element, a first right-angle reflector, and a second right-angle reflector. After the first incident beam 612 and the second incident beam 613 (i.e., the incident laser) enter the read head 100, they are diffracted once by the one-dimensional grating 200 to form a diffracted beam. Then, with the assistance of the aforementioned retroreflective elements and right-angle reflectors, they undergo two or more diffractions and / or two reflections to form a first feedback laser and a second feedback laser. When the read head forms the feedback laser, the incident laser undergoes a relatively large number of diffractions, which can compensate for the spot deviation caused by the movement of the one-dimensional grating in the X direction, thus helping to increase the measurement range of the displacement measuring device in the X direction.

[0057] The displacement measuring device in this embodiment has at least the following advantages: First, it achieves two-dimensional measurement of the displacement of the one-dimensional grating 200 along the X-axis and Y-axis at low cost; second, it obtains the displacement information of the corresponding one-dimensional grating 200 based on the phase change information of the interference signal of each feedback laser, without the need for algorithm decoupling; third, by making the mutually separated first incident beam 610 and second incident beam 611 parallel to contact the one-dimensional grating 200 to cause diffraction, and guiding and combining the diffracted first incident beam 610 and second incident beam 611 to form corresponding feedback lasers (first feedback laser 612 and second feedback laser 613), and processing the feedback lasers, the displacement of the one-dimensional grating 200 along the X-axis is obtained. The displacement along the Y-axis can eliminate the coherent light angle separation caused by the deflection of the one-dimensional grating 200 (e.g., deflection relative to the normal direction of the one-dimensional grating 200), that is, the measurement process has a wide angle adaptability, which helps to reduce the influence of the deflection of the one-dimensional grating 200 on the intensity of interference information and improve the measurement accuracy. In addition, it also helps to improve the angle tolerance of the displacement measuring device and reduce the difficulty of installation and attitude control of the displacement measuring device. Fourth, the two incident beams of the input reading head 100 are separated from each other. During the measurement process, the beams do not affect each other and are only combined before the final interference. Compared with the measurement system that is prone to frequency aliasing through the same input beam, it can greatly reduce or even avoid nonlinear errors caused by the common optical path structure.

[0058] Example 2

[0059] This embodiment mainly describes a motion stage system, which includes a motion stage and a displacement measuring device connected to the motion stage. The displacement measuring device includes at least two gratings and a read head used in conjunction with each of the gratings. Each grating has at least a plurality of diffraction units arranged in a one-dimensional manner and an incident light surface coplanar with the plurality of diffraction units. Each grating extends along the surface of the motion stage to form a one-dimensional dimension. The incident light surfaces of at least two of the gratings are non-parallel surfaces. The displacement measuring device calculates the displacement of the motion stage in the length direction of each of the gratings and the displacement in the normal direction of each of the gratings, thereby calculating the positional change of the motion stage in more than three degrees of freedom.

[0060] In the motion stage system of this embodiment, the motion stage can be a linear motion stage, a workpiece stage in a lithography device used to place a substrate (such as a wafer), or a mask stage in a lithography device used to place a photomask. In the displacement measuring device, each set of one-dimensional gratings and read heads used in conjunction can adopt the principle and structure described in Embodiment 1.

[0061] In this embodiment, the displacement measuring device may include at least two one-dimensional gratings. That is, the gratings in this embodiment can be one-dimensional gratings, and each one-dimensional grating can be extended along the surface of the motion stage to form a one-dimensional dimension. In another embodiment, the gratings can also be two-dimensional gratings, but only one dimension of the two-dimensional grating can be used in practice. The motion stage system will be described below using a one-dimensional grating as an example.

[0062] Figure 4 This is a schematic diagram of the motion table system according to Embodiment 2 of the present invention. Figure 5 for Figure 4 A cross-sectional schematic diagram of the motion table system in the XZ plane. Figure 6 This is a system layout diagram of the motion table system according to Embodiment 2 of the present invention. Figure 4 , Figure 5 and Figure 6 As shown, the motion table can be located in a first orthogonal coordinate system, and the origin O of the first orthogonal coordinate system is the motion center of the motion table. The first orthogonal coordinate system may include mutually orthogonal X-axis, Y-axis and Z-axis. The motion table has translational degrees of freedom along the X-axis, Y-axis and / or Z-axis respectively, and rotational degrees of freedom in the XZ plane, YZ plane and / or XY plane respectively.

[0063] The displacement measuring device may include a first one-dimensional grating 201, a second one-dimensional grating 202, a first reading head 101 and a third reading head 103 used in conjunction with the first one-dimensional grating 201, and a second reading head 102 used in conjunction with the second one-dimensional grating 202.

[0064] like Figure 4 and Figure 6 As shown, the motion stage 800 may have a first sidewall 800a parallel to the light-incident surface of the first one-dimensional grating 201 and a second sidewall 800b parallel to the light-incident surface of the second one-dimensional grating 202. The length direction of the first one-dimensional grating 201 may be the same as the length direction of the first sidewall 800a, and the first one-dimensional grating 201 may be disposed on the first sidewall 800a; the length direction of the second one-dimensional grating 202 may be the same as the length direction of the second sidewall 800b, and the second one-dimensional grating 202 may be disposed on the second sidewall 800b.

[0065] To make the movement of the motion table 800 smoother and improve the stability of the equipment, the first sidewall 800a and the second sidewall 800b can be connected to the lower surface 800c of the motion table 800 respectively, and the included angles between them and the lower surface 800c are both obtuse angles. The first sidewall 800a and the second sidewall 800b are symmetrical about the Z-axis in the first orthogonal coordinate system. For example, the included angles between the first sidewall 800a and the second sidewall 800b and the lower surface 800c can both be 135 degrees.

[0066] To increase the bonding strength of the one-dimensional grating, reduce its deformation, decrease the dimension extending outward from the side of the motion stage 800, and improve the stability, modalities, and measurement accuracy of the motion stage system, both the first one-dimensional grating 201 and the second one-dimensional grating 202 have a back surface facing away from the incident light surface. The back surface of the first one-dimensional grating 201 can be bonded to the first sidewall 800a, and / or the back surface of the second one-dimensional grating 202 can be bonded to the second sidewall 800b. In another embodiment, the first one-dimensional grating 201 can be formed on the first sidewall 800a by etching, and / or the second one-dimensional grating 202 can be formed on the second sidewall 800b by etching.

[0067] like Figure 5 As shown, the displacement measuring device can be located in a second orthogonal coordinate system, which may include mutually orthogonal X' and Y' axes. Figure 5 Not shown in the image, for example, with Figure 4 The first orthogonal coordinate system is parallel to the Y-axis and the second orthogonal coordinate system, and the Z' axis and the origin O' are also defined. The Y' axis can be set along the length direction of the first one-dimensional grating 201 and the second one-dimensional grating 202. The Z' axis is perpendicular to the light-incident surface of the first one-dimensional grating 201. The X' axis has an angle of less than 90 degrees with the normal direction of the second one-dimensional grating 202 (for example, the light-incident surface of the second one-dimensional grating 202 is perpendicular to the X' axis). The first reading head 101 and the third reading head 103 have a first preset distance greater than zero along the direction of the X' axis. The first orthogonal coordinate system can be obtained by projection transformation from the second orthogonal coordinate system.

[0068] In this embodiment, the displacement measuring device can use the first reading head 101 and the first one-dimensional grating 201 to obtain the first displacement d of the first one-dimensional grating 201 along the Y' axis. Y1 and the second displacement d along the Z' axis Z2 The third displacement d of the second one-dimensional grating 202 along the Y' axis can be obtained using the second read head 102 and the second one-dimensional grating 202. Y3 and the fourth displacement d along the X' axisX4 Furthermore, the third read head 103 and the first one-dimensional grating 201 can be used to obtain the fifth displacement d of the first one-dimensional grating 201 along the Y' axis. Y5 and the sixth displacement d along the Z' axis Z6 .

[0069] It should be noted that, in this embodiment, each displacement refers to the position change vector of the one-dimensional grating or motion stage along a certain axis. For example, the first displacement is the position change vector of the first one-dimensional grating 201 along the Y' axis.

[0070] In this embodiment, the displacement measuring device uses a one-dimensional grating and a reader used in conjunction with it to obtain the displacement of the motion stage 800 in the length direction of each one-dimensional grating and in the normal direction of each one-dimensional grating. This method is similar to the method in Embodiment 1 where the displacement measuring device uses a one-dimensional grating 200 and a reader 101 to obtain the displacement of the one-dimensional grating 200 along the length direction of the one-dimensional grating 200 and along the normal direction of the one-dimensional grating 200. For details, please refer to the description in Embodiment 1.

[0071] As an example, the displacement measuring device may further include a laser source, a detection unit, and a processing unit; the laser source emits two parallel incident laser beams toward the first read head 101, which, guided by the first read head 101, illuminate the incident surface of the first one-dimensional grating 201. After diffraction and / or reflection by the first one-dimensional grating 201, at least two feedback laser beams are output through the first read head 101. The detection unit and the processing unit detect and process the two feedback laser beams respectively to obtain the first displacement d of the first one-dimensional grating 201 along the Y' axis. Y1 and the second displacement d along the Z' axis Z2 The displacement measuring device uses the second reading head 102 and the second one-dimensional grating 202 to obtain the third displacement d of the second one-dimensional grating 202. Y3 and the fourth displacement d X4 And using the third read head 103 and the first one-dimensional grating 201, the fifth displacement d of the first one-dimensional grating 201 is obtained. Y5 and the sixth displacement d along the Z' axis Z6 The method for obtaining the first displacement d of the first one-dimensional grating 201 Y1 Second displacement quantity d Z2The method is similar and will not be described in detail here. Specifically, the two parallel incident laser beams guided by the first read head 101 form two light spots on the light-incident surface of the first one-dimensional grating 101. The midpoint between the center points of the two light spots is taken as the center point (which can be called the nominal center) formed by the incident laser beams guided by the first read head 101 on the light-incident surface of the first one-dimensional grating 101. Furthermore, for each pair of one-dimensional gratings and read heads used in conjunction, the incident laser beams guided by the read head (each including two parallel incident laser beams) form a center point on the light-incident surface of the corresponding one-dimensional grating.

[0072] In this embodiment, the displacement measuring device can utilize the first displacement d respectively. Y1 The second displacement d Z2 The third displacement d Y3 The fourth displacement d X4 The fifth displacement d Y5 and the sixth displacement d Z6 At least one of these is used to calculate or represent the displacement of the motion table 800 along the X' axis, the Y' axis, and the Z' axis, and to calculate the rotation R' of the motion table 800 in the X'Z' plane. Y Rotational amount R' in the Y'Z' plane X and the rotation R' in the X'Y' plane Z The rotation amount R' X 、R' Y 、R' Z These can be the rotational radians of the motion table 800 in the Y'Z', X'Z', and X'Y' planes, respectively.

[0073] Specifically, the displacement of the motion table 800 along the X' axis can be equal to the fourth displacement d. X4 The displacement along the Y' axis can be equal to the first displacement d. Y1 The third displacement d Y3 Or the fifth displacement d Y5 The displacement along the Z' axis can be equal to the second displacement d. Z2 Or the sixth displacement d Z6 In another embodiment, to reduce measurement errors and improve the accuracy of the obtained position change of the motion table, a first displacement d can be used. Y1 The third displacement d Y3 and the fifth displacement d Y5 The average value is taken as the displacement of the motion table 800 along the Y' axis, and the second displacement d can be used. Z2 and the sixth displacement d Z6The average value is taken as the displacement of the motion table 800 along the Z' axis.

[0074] The X'Z' plane is a two-dimensional plane defined by the X' axis and the Z' axis, the Y'Z' plane is a two-dimensional plane defined by the Y' axis and the Z' axis, and the X'Y' plane is a two-dimensional plane defined by the X' axis and the Y' axis.

[0075] The rotational amount R'y of the motion table 800 in the X'Z' plane can be controlled by the second displacement d. Z6 and the sixth displacement d Z6 The rotation amount R' was calculated to be... Y The following relation can be satisfied: R' Y =(d Z2 -d Z6 ) / ΔX', where d Z2 Let d be the second displacement. Z6 The sixth displacement is ΔX', where ΔX' is the first preset spacing (e.g., ...). Figure 5 (as shown in the image).

[0076] The rotational amount R'x of the motion table 800 in the Y'Z' plane can be controlled by the first displacement d. Y1 The rotation amount R' was calculated to be... X The following relation can be satisfied: R' X =d Y1 / D O'A , where d Y1 Let d be the first displacement. O'A The distance between the center point A formed by the incident laser guided by the first read head 101 on the incident surface of the first one-dimensional grating 201 and the origin O'.

[0077] In another embodiment, the rotation R'x of the motion table 800 in the Y'Z' plane can be controlled by the fifth displacement d. Y5 The rotation amount R' was calculated to be... X The following relation can be satisfied: R' X =d Y5 / D O'A , where d Y5 For the fifth displacement, D O'A The distance between the center point formed by the incident laser guided by the third read head 103 on the incident surface of the first one-dimensional grating 201 and the origin O'.

[0078] The rotation amount R'z of the motion table 800 in the X'Y' plane can be obtained by calculating the third displacement amount, the rotation amount R' ZThe following relation can be satisfied: R' Z =d Y3 / D O'B , where d Y3 For the third displacement, D O'B The distance between the center point B formed by the incident laser guided by the second read head 102 on the incident surface of the second one-dimensional grating 202 and the origin O'.

[0079] In this embodiment, the displacements of the motion table along the X, Y, and Z axes of the first coordinate system can be obtained by projecting the displacements along the X', Y', and Z' axes of the second coordinate system, respectively; the rotation R of the motion table in the XZ plane of the first coordinate system... Y Rotational amount R in the YZ plane X and the rotation amount R in the XY plane Z It can be derived from the above R' Y 、R' X and R' Z The position changes between the two coordinate systems are obtained through projection transformation. Those skilled in the art can use well-known projection transformation methods to transform the position changes between the two coordinate systems. In this embodiment, the displacement of the motion stage 800 along the Y-axis can be greater than the displacement along the X-axis and the Z-axis.

[0080] In this embodiment, the displacement measuring device includes two one-dimensional gratings (i.e., the first one-dimensional grating 201 and the second one-dimensional grating 202) and three reading heads (i.e., the first reading head 101, the second reading head 102, and the third reading head 103). However, it is not limited to this. In one embodiment, the displacement measuring device may further include a fourth reading head, which works in conjunction with the second one-dimensional grating 202. The second reading head 102 and the fourth reading head have a second preset distance greater than zero in the width direction of the second one-dimensional grating 202. The displacement measuring device can obtain the seventh displacement of the second one-dimensional grating 202 along the Y' axis and the eighth displacement along the X' axis using the fourth reading head and the second one-dimensional grating 202. Adding a fourth reading head allows the displacement measuring device to obtain more position change information. The seventh and eighth displacements can be used to calculate the displacement of the motion stage 800 in the second orthogonal coordinate system, for example, helping to eliminate measurement errors in the displacement measuring device and improve the position change measurement accuracy of the motion stage.

[0081] The motion stage system of this embodiment includes a motion stage 800 and a displacement measuring device connected to the motion stage 800. The displacement measuring device includes at least two one-dimensional gratings (e.g., a first one-dimensional grating 201 and a second one-dimensional grating 202) and read heads (e.g., a first read head 101, a second read head 102, and a third read head 103) used in conjunction with each of the one-dimensional gratings. Each one-dimensional grating has a plurality of diffraction units arranged in a one-dimensional manner and an incident light surface coplanar with the plurality of diffraction units. Each of the one-dimensional gratings extends along the surface of the motion stage to form a one-dimensional dimension, and the incident light surfaces of at least two of the one-dimensional gratings are non-parallel surfaces. The displacement measuring device calculates the displacement of the motion stage in the length direction of each of the one-dimensional gratings and the displacement in the normal direction of each of the one-dimensional gratings, thereby calculating the positional change of the motion stage in more than three degrees of freedom. On the one hand, the motion stage system uses at least two one-dimensional gratings and read heads that work in conjunction with each one-dimensional grating to measure the positional changes of the motion stage in more than three degrees of freedom. Compared with the prior art, which uses two-dimensional gratings and corresponding read heads for displacement measurement, the cost of one-dimensional gratings is lower than that of two-dimensional gratings, thus helping to reduce the cost of the motion stage system. On the other hand, the displacement measuring device of the motion stage system can measure the positional changes of the motion stage 800 in six degrees of freedom, providing a more comprehensive measurement of the positional changes of the motion stage 800 and improving the system's ability to measure the positional changes of the motion stage 800. Furthermore, compared with the prior art, which uses two two-dimensional gratings extending from the side of the mask stage clamp (e.g., ...), the motion stage system is more cost-effective. Figure 1 As shown in the figure, in this embodiment, each of the one-dimensional gratings of the displacement measuring device extends along the surface of the motion stage. For example, the back of each one-dimensional grating is adhered (attached) to the side wall of the motion stage 800 or formed by etching on the side wall. This can reduce the size of the side extension of the motion stage 800, which helps to improve the modality of the motion stage system and improve the stability of the motion stage system.

[0082] Example 3

[0083] This embodiment mainly describes a motion table system. The main difference between this motion table system and Embodiment 2 is that the displacement measuring device of the motion table system includes three one-dimensional gratings and three read heads corresponding to each one-dimensional grating. Furthermore, the positional arrangement of each one-dimensional grating and its corresponding read head is also different from that in Embodiment 2. In this embodiment, the displacement measuring device can directly calculate the displacement of the one-dimensional gratings in the first orthogonal coordinate system where the motion table is located, thereby obtaining the position change information of the motion table.

[0084] Figure 7 This is a schematic diagram of the motion table system according to Embodiment 3 of the present invention. Figure 8 for Figure 7A cross-sectional schematic diagram of the motion table system in the XZ plane. Figure 9 This is a system layout diagram of the motion table system according to Embodiment 3 of the present invention. Figures 7 to 9 As shown, the motion table system includes a motion table 800 and a displacement measuring device connected to the motion table 800.

[0085] The motion table 800 can be located in a first orthogonal coordinate system, the origin O of the first orthogonal coordinate system is the motion center of the motion table 800, the first orthogonal coordinate system includes mutually orthogonal X-axis, Y-axis and Z-axis, the motion table has translational degrees of freedom along the X-axis, Y-axis and / or Z-axis respectively, and rotational degrees of freedom in the XZ plane, YZ plane and / or XY plane respectively.

[0086] In this embodiment, the displacement measuring device may include a first one-dimensional grating 201, a second one-dimensional grating 202, a third one-dimensional grating 203, a first reading head 101 used in conjunction with the first one-dimensional grating 201, a second reading head 102 used in conjunction with the second one-dimensional grating 202, and a third reading head 103 used in conjunction with the third one-dimensional grating 203; the length directions of the first one-dimensional grating 201, the second one-dimensional grating 202, and the third one-dimensional grating 203 may all be parallel to the Y-axis; the light incident surfaces of the first one-dimensional grating 201 and the second one-dimensional grating 202 may be opposite to each other and both perpendicular to the X-axis; and the light incident surface of the third one-dimensional grating 203 may be perpendicular to the Z-axis.

[0087] The motion stage 800 may have a first sidewall 800a and a second sidewall 800b that are oppositely arranged and perpendicular to the X-axis. The first one-dimensional grating 201 may be disposed on the first sidewall 800a, and the second one-dimensional grating 202 may be disposed on the second sidewall 800b. The motion stage 800 may also have a lower surface 800c that is perpendicular to the first sidewall 800a and the second sidewall 800b, and the third one-dimensional grating 203 may be disposed on the lower surface 800c.

[0088] The first one-dimensional grating 201, the second one-dimensional grating 202, and the third one-dimensional grating may all have a back surface facing away from the incident light surface. To increase the bonding strength of the one-dimensional gratings, reduce their deformation, decrease the dimension extending outwards from the side of the motion stage 800, and improve the stability and modality of the motion stage system, the back surface of the first one-dimensional grating 201 may be bonded to the first sidewall 800a, the back surface of the second one-dimensional grating 202 may be bonded to the second sidewall 800b, and / or, the back surface of the third one-dimensional grating 203 may be bonded to the lower surface 800c of the motion stage. In another embodiment, the first one-dimensional grating 201 may be formed on the first sidewall 800a by etching, the second one-dimensional grating 202 may be formed on the second sidewall 800b by etching, and / or, the third one-dimensional grating may be formed on the lower surface 800c of the motion stage by etching.

[0089] The displacement measuring device can use the first read head 101 and the first one-dimensional grating 201 to obtain the first displacement of the first one-dimensional grating 201 along the Y-axis and the second displacement along the X-axis, can use the second read head 102 and the second one-dimensional grating 202 to obtain the third displacement of the second one-dimensional grating 202 along the Y-axis and the fourth displacement along the X-axis, and can use the third read head 103 and the third one-dimensional grating 203 to obtain the fifth displacement of the third one-dimensional grating 203 along the Y-axis and the sixth displacement along the Z-axis.

[0090] The displacement measuring device can calculate or use as the displacement of the motion table along the X-axis, Y-axis, and Z-axis using at least one of the first displacement, second displacement, third displacement, fourth displacement, fifth displacement, and sixth displacement, and calculate the rotation R of the motion table in the XZ plane. Y Rotational amount R in the YZ plane X and the rotation R in the XY plane Z In this embodiment, the displacement amounts are all one-dimensional gratings or motion stages, representing displacement vectors along a certain axis. The rotation amount R... X R Y R Z These can be the rotational radians of the motion table 800 in the YZ, XZ, and XY planes, respectively.

[0091] Specifically, the displacement of the motion table 800 along the X-axis can be equal to the second displacement, the fourth displacement, or the average of the second and fourth displacements; the displacement along the Y-axis can be equal to the first displacement, the third displacement, the fifth displacement, or the average of the three; and the displacement along the Z-axis can be equal to the sixth displacement.

[0092] The rotational amount R of the motion table 800 in the XZ plane Y The rotation amount R can be calculated using the sixth displacement. Y The following relation can be satisfied: R Y =d Z6 / L X , where d Z6 L is the sixth displacement. X The distance between the center point of the incident laser guided by the third read head 103 on the incident surface of the third one-dimensional grating 203 and the origin O in the X-axis direction (e.g., Figure 8 (As shown).

[0093] The rotational amount R of the motion table 800 in the YZ plane X The rotation amount R can be calculated from the first displacement and the fifth displacement. X The following relationship can be satisfied:

[0094] R X =d Y5 / ΔZ, where d Y5 The fifth displacement is ΔZ, which is the distance along the Z-axis between the center point formed by the incident laser guided by the first read head 101 on the incident surface of the first one-dimensional grating 201 and the center point formed by the incident laser guided by the third read head 103 on the incident surface of the third one-dimensional grating 203 (e.g., ...). Figure 8 (As shown).

[0095] The rotational amount R of the motion table 800 in the YZ plane Z The rotation amount R can be calculated from the first displacement and the third displacement. Z The following relationship can be satisfied:

[0096] R Z =(d Y1 -d Y3 ) / ΔX, where d Y1 Let d be the first displacement. Y3 The third displacement is ΔX, which is the distance between the light-incident surface of the first one-dimensional grating 201 and the light-incident surface of the second one-dimensional grating 202 in the X-axis direction.

[0097] The motion stage system of this embodiment has the following technical effects: (1) The motion stage system uses three one-dimensional gratings and a read head used in conjunction with each one-dimensional grating to measure the position changes of the motion stage 800 in six degrees of freedom. Compared with the prior art, which uses two-dimensional gratings and corresponding read heads for displacement measurement, the cost of one-dimensional gratings is lower than that of two-dimensional gratings, which helps to reduce the cost of the motion stage system; (2) The displacement measuring device of the motion stage system can measure the displacement of the motion stage 800 in the length direction of each one-dimensional grating and the displacement in the normal direction of each one-dimensional grating, and then calculate the position changes of the motion stage 800 in six degrees of freedom. The measurement of the position changes of the motion stage is more comprehensive, which can improve the measurement capability of the motion stage system for the position changes of the motion stage 800; (3) Compared with the prior art, where two two-dimensional gratings extend from the side of the mask stage clamp, each one-dimensional grating of the displacement measuring device extends along the surface of the motion stage 800, which helps to improve the modality of the motion stage system.

[0098] Example 4

[0099] This embodiment provides a photolithography apparatus, which may include the aforementioned motion stage system. The motion stage is a mask stage or a workpiece stage. The motion stage system includes a motion stage and a displacement measuring device connected to the motion stage. The displacement measuring device includes at least two one-dimensional gratings and a read head used in conjunction with each of the one-dimensional gratings. Each one-dimensional grating has a plurality of diffraction units arranged in a one-dimensional manner and an incident surface coplanar with the plurality of diffraction units. Each one-dimensional grating extends along the surface of the motion stage, and the incident surfaces of at least two of the one-dimensional gratings are non-parallel. The displacement measuring device calculates the displacement of the motion stage in three or more degrees of freedom by calculating the displacement of the motion stage in the length direction of each one-dimensional grating and the displacement in the normal direction of each one-dimensional grating.

[0100] Since the cost of one-dimensional gratings is lower than that of two-dimensional gratings, the displacement measurement device of the motion stage system in the lithography equipment, using at least two one-dimensional gratings and a read head used in conjunction with each of the one-dimensional gratings, can obtain the positional changes of the motion stage in more than three degrees of freedom, which helps to reduce the cost of the lithography equipment. Moreover, the motion stage system can obtain the positional changes of the motion stage in multiple degrees of freedom, which helps to improve the lithography equipment's ability to measure the positional changes of the motion stage and can improve the performance of the lithography equipment.

[0101] It should be noted that this instruction manual uses a progressive approach, with later descriptions focusing on the differences from earlier descriptions. Similarities and similarities between different sections can be found by referring to each other.

[0102] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A motion stage system, characterized by, The displacement measuring device comprises at least two gratings and a reading head used in cooperation with each of the gratings; each of the gratings has a plurality of diffraction units arranged in one dimension and an incident surface coplanar with the diffraction units; each of the gratings is elongated along the surface of the moving table to form a one-dimensional dimension, and the incident surfaces of the at least two gratings are non-parallel surfaces; the displacement measuring device calculates the displacement of the moving table in the length direction of each of the gratings and in the normal direction of each of the gratings, and then calculates the position change of the moving table in six degrees of freedom. The moving table is located in a first orthogonal coordinate system, the coordinate origin O of the first orthogonal coordinate system is the motion center of the moving table, and the first orthogonal coordinate system comprises mutually orthogonal X, Y and Z axes; the displacement measuring device comprises a first one-dimensional grating, a second one-dimensional grating, a third one-dimensional grating, and a first reading head, a second reading head and a third reading head used in cooperation with the first one-dimensional grating, the second one-dimensional grating and the third one-dimensional grating respectively; the length directions of the first one-dimensional grating, the second one-dimensional grating and the third one-dimensional grating are parallel to the Y axis, the incident surfaces of the first one-dimensional grating and the second one-dimensional grating are opposite to each other and perpendicular to the X axis, and the incident surface of the third one-dimensional grating is perpendicular to the Z axis.

2. The motion stage system of claim 1, wherein, The moving table has translational degrees of freedom along the X, Y and / or Z axes, and has rotational degrees of freedom in the XZ, YZ and / or XY planes.

3. The motion stage system of claim 2, wherein, The displacement measuring device obtains, by using the first reading head and the first one-dimensional grating, a first displacement of the first one-dimensional grating along the Y axis and a second displacement of the first one-dimensional grating along the X axis, obtains, by using the second reading head and the second one-dimensional grating, a third displacement of the second one-dimensional grating along the Y axis and a fourth displacement of the second one-dimensional grating along the X axis, and obtains, by using the third reading head and the third one-dimensional grating, a fifth displacement of the third one-dimensional grating along the Y axis and a sixth displacement of the third one-dimensional grating along the Z axis. The displacement of the moving table along the X axis is equal to the second displacement or the fourth displacement, the displacement of the moving table along the Y axis is equal to the first displacement, the third displacement or the fifth displacement, and the displacement of the moving table along the Z axis is equal to the sixth displacement.

4. The motion stage system of claim 3, wherein, the amount of rotation R of the motion stage in the XZ plane Y the amount of rotation R in the YZ plane X the amount of rotation R in the XY plane Z satisfies the following relationship: R Y =d Z6 / L X , wherein d Z6 is the sixth displacement amount, L X is the distance between the center point formed by the incident laser of the third read head guide on the light entrance surface of the third one-dimensional grating and the origin O in the X-axis direction; R X = d Y5 / ΔZ, wherein d Y5 is the fifth displacement amount, and ΔZ is the distance in the Z-axis direction between the center point formed by the incident laser guided by the first reading head on the light entrance surface of the first one-dimensional grating and the center point formed by the incident laser guided by the third reading head on the light entrance surface of the third one-dimensional grating. R Z = (d Y1 -d Y3 ) / ΔX, wherein d Y1 is the first displacement amount, d Y3 is the third displacement amount, and ΔX is the interval between the entrance surface of the first one-dimensional grating and the entrance surface of the second one-dimensional grating in the X-axis direction.

5. The motion stage system of claim 2, wherein, The moving table has a first side wall and a second side wall arranged opposite to each other and perpendicular to the X axis, the first one-dimensional grating is attached to the first side wall or formed by etching the first side wall, and the second one-dimensional grating is attached to the second side wall or formed by etching the second side wall; the moving table also has a lower surface perpendicular to the first side wall and the second side wall, and the third one-dimensional grating is attached to the lower surface or formed by etching the lower surface.

6. The motion stage system of claim 2, wherein, The displacement measuring device comprises a first one-dimensional grating, a second one-dimensional grating, a first reading head and a third reading head used in cooperation with the first one-dimensional grating, and a second reading head used in cooperation with the second one-dimensional grating; the displacement measuring device is located in a second orthogonal coordinate system comprising mutually orthogonal X' axis, Y' axis and Z' axis and an origin O'; the Y' axis is arranged along the length direction of the first one-dimensional grating and the second one-dimensional grating, the Z' axis is perpendicular to the light-incident surface of the first one-dimensional grating, the X' axis has an included angle less than 90 degrees with the normal direction of the second one-dimensional grating, and the first reading head and the third reading head have a first preset interval greater than zero along the direction of the X' axis; the first orthogonal coordinate system is obtained by projection conversion of the second orthogonal coordinate system.

7. The motion stage system of claim 6, wherein, The light-incident surface of the second one-dimensional grating is perpendicular to the X' axis; the displacement measuring device obtains a first displacement amount of the first one-dimensional grating along the Y' axis and a second displacement amount of the first one-dimensional grating along the Z' axis by using the first reading head and the first one-dimensional grating, obtains a third displacement amount of the second one-dimensional grating along the Y' axis and a fourth displacement amount of the second one-dimensional grating along the X' axis by using the second reading head and the second one-dimensional grating, and obtains a fifth displacement amount of the first one-dimensional grating along the Y' axis and a sixth displacement amount of the first one-dimensional grating along the Z' axis by using the third reading head and the first one-dimensional grating; the displacement amount of the motion stage along the X' axis is equal to the fourth displacement amount, the displacement amount of the motion stage along the Y' axis is equal to the first displacement amount, the third displacement amount or the fifth displacement amount, and the displacement amount of the motion stage along the Z' axis is equal to the second displacement amount or the sixth displacement amount.

8. The motion stage system of claim 7, wherein, the amount of rotation R' of the motion stage in the X'Z' plane Y the amount of rotation R' of the motion stage in the Y'Z' plane X the amount of rotation R' of the motion stage in the X'Y' plane Z satisfies the following relationship: R' Y = (d Z2 -d Z6 ) / ΔX', wherein d Z2 is the second displacement amount, d Z6 is the sixth displacement amount, and ΔX' is the first preset interval. R' X =d Y1 / D O'A , wherein d Y1 is the first displacement amount, d Y5 is the fifth displacement amount, and D O'A is the distance between the center point formed by the incident laser of the first read head guide on the light entrance surface of the first one-dimensional grating and the origin O'. R' Z = d Y3 / D O'B , wherein d Y3 is the third displacement amount, and D O'B is the distance between the center point formed by the incident laser guided by the second reading head at the light entrance surface of the second one-dimensional grating and the origin point O'.

9. The motion stage system of claim 6, wherein, The motion stage has a first side wall parallel to the light-incident surface of the first one-dimensional grating and a second side wall parallel to the light-incident surface of the second one-dimensional grating; the length direction of the first one-dimensional grating is the same as the length direction of the first side wall, and the first one-dimensional grating is attached to the first side wall or formed by etching the first side wall; the length direction of the second one-dimensional grating is the same as the length direction of the second side wall, and the second one-dimensional grating is attached to the second side wall or formed by etching the second side wall.

10. The motion stage system of claim 9, wherein, The first side wall and the second side wall are respectively connected with the lower surface of the motion stage and have an obtuse angle with the lower surface of the motion stage, and the first side wall and the second side wall are symmetric about the Z axis in the first orthogonal coordinate system.

11. A lithographic apparatus, characterized in that, The photolithography equipment comprises the motion stage system as claimed in any one of claims 1 to 10, wherein the motion stage is a mask stage or a workpiece stage.

Images