CN212806922U

CN212806922U - Displacement measuring device, mask table measuring system and photoetching machine

Info

Publication number: CN212806922U
Application number: CN202021866735.XU
Authority: CN
Inventors: 吴萍
Original assignee: Shanghai Micro Electronics Equipment Co Ltd
Current assignee: Shanghai Micro Electronics Equipment Co Ltd
Priority date: 2020-08-31
Filing date: 2020-08-31
Publication date: 2021-03-26
Anticipated expiration: 2030-08-31

Abstract

The utility model provides a displacement measuring device, a mask stage measuring system and a photoetching machine, wherein the displacement measuring device comprises a light source, a first direction displacement measuring component, a second direction displacement measuring component, a light detection module and a light signal processing module, and the first direction and the second direction are mutually vertical; the light source is used for emitting a first measuring light beam and a second measuring light beam; the first direction displacement measuring component comprises a grating and a reading head which are oppositely arranged; the reading head comprises two symmetrically arranged retroreflectors; the second direction displacement measurement assembly comprises an interferometer and a reflecting element which are oppositely arranged; the optical detection module is used for detecting a first direction displacement interference signal and a second direction displacement interference signal; the optical signal processing module is used for calculating the first direction displacement and the second direction displacement. The utility model discloses an adopt the combination of one-dimensional grating and reflection element, can realize the measurement of two-dimensional displacement volume, not only with low costs, the performance is high, has wide angle adaptability moreover, and it is more convenient to use.

Description

Displacement measuring device, mask table measuring system and photoetching machine

Technical Field

The utility model relates to a lithography machine equipment technical field, in particular to displacement measurement device, mask platform measurement system and lithography machine.

Background

The nanometer measurement technology is the basis of the fields of nanometer processing, nanometer control, nanometer materials and the like. High-resolution and high-precision displacement sensors are required in the IC industry, precision machinery, micro-electro-mechanical systems and the like to achieve nanometer precision positioning.

With the rapid development of the integrated circuit towards large scale and high integration, the alignment precision requirement of the photoetching machine is higher and higher, and correspondingly, the precision of acquiring the six-degree-of-freedom position information of the workpiece table and the mask table is improved.

The interferometer has high measurement precision, can reach nanometer level, and is used for measuring the positions of a workpiece table and a mask table in a photoetching system. However, the measurement accuracy of the current interferometer almost reaches the limit, meanwhile, the measurement accuracy of the interferometer is greatly influenced by the surrounding environment, the measurement repetition accuracy is not high (even if the environment is good, the measurement repetition accuracy exceeds 1nm), and the traditional interferometer measurement system is difficult to meet the requirement of further improving the alignment accuracy. Therefore, a high-precision and high-stability picometer measurement scheme is urgently needed.

In contrast, the optical path of the grating ruler measurement system can be very small, usually several millimeters, and the optical path is independent of the measurement range, so that the measurement precision of the grating ruler measurement system is insensitive to the environmental influence, and the grating ruler measurement system has the characteristics of high measurement stability, simple structure and easiness in miniaturization, and occupies an important place in the field of nano measurement. Interferometers are gradually replaced in a new generation of photoetching systems, and the tasks of high-precision and high-stability picometer precision measurement are undertaken.

Patent US7289212B2 discloses a motion stage planar grating measurement system comprising at least one grating and a two-dimensional measuring read head placed opposite thereto. The motion table plane grating measuring system adopts at least one grating, and the grating is a two-dimensional grating, so that the cost is high, and the processing difficulty is high; and the system has low light power utilization rate and much stray light.

Patent CN101479832B discloses an apparatus for interferometric measurement using diffracted light generated by a moving grid, which uses a moving grid and a fixed grid together to realize interferometric measurement, and has the advantages that: the size of the motion table can be reduced, and the positioning measurement precision of the motion table is improved; the disadvantages are that: when the motion platform rotates relative to the optical system, the quality of interference signals is reduced, and the measurement scheme does not have wide-angle adaptability.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a displacement measurement device, mask platform measurement system and lithography machine can solve current displacement measurement device with high costs, the processing degree of difficulty is big, the light utilization rate is low and do not have wide angle adaptability scheduling problem.

In order to solve the technical problem, the utility model provides a displacement measurement device, including light source, first direction displacement measurement subassembly, second direction displacement measurement subassembly, light detection module and light signal processing module, first direction with second direction mutually perpendicular:

the light source is used for emitting a first measuring light beam and a second measuring light beam, and the first measuring light beam is divided into two beams;

the first direction displacement measurement assembly comprises a grating and a reading head which are oppositely arranged; the reading head comprises two symmetrically arranged retroreflectors;

the second direction displacement measurement assembly comprises an interferometer and a reflecting element which are oppositely arranged;

two beams of the first measuring light beams are respectively incident to the grating through the reading head and are diffracted on the surface of the grating, two beams of the first diffraction light beams are respectively projected to corresponding retroreflectors and are retroreflected to the surface of the grating through the retroreflectors to be subjected to secondary diffraction, and the two beams of the second diffraction light beams are converged to form a first direction displacement interference signal;

the second measuring beam is incident to the reflecting element through the interferometer, reflected to the interferometer through the reflecting element and forms a second direction displacement interference signal;

the optical detection module is used for detecting the first direction displacement interference signal and the second direction displacement interference signal;

the optical signal processing module is used for calculating a first direction displacement according to the first direction displacement interference signal and calculating a second direction displacement according to the second direction displacement interference signal.

Optionally, the reflective element is a strip mirror.

Optionally, the working surface of the grating and the working surface of the reflecting element are located on the same plane.

Optionally, the retroreflector is a pyramid prism, a right-angle prism, a cat eye reflector, a dove prism, a hollow retroreflector or a grating reflector.

Optionally, the cat-eye reflector includes a lens and a concave reflector, the center of sphere of the concave reflector coincides with the center of the lens, and the focal point of the lens is located on the reflecting surface of the concave reflector.

Optionally, the hollow retroreflector includes three mutually perpendicular reflecting surfaces.

Optionally, the grating reflector comprises a transmissive grating and a reflective prism.

In order to solve the above technical problem, the utility model provides a mask stage measurement system is still provided, mask stage measurement system includes at least a set of above displacement measurement device, first direction displacement measurement subassembly is used for measuring mask stage is along the displacement of Y to, second direction displacement measurement subassembly is used for measuring mask stage is along the displacement of X to.

Optionally, the back surface of the grating and the back surface of the reflection element are both mounted on a side surface of the mask stage arranged along the Y direction.

Optionally, the mask stage measuring system includes two sets of displacement measuring devices as described above, and the two sets of displacement measuring devices are respectively installed on two sides of the mask stage.

In order to solve the technical problem, the utility model also provides a lithography machine, lithography machine includes the above displacement measurement device.

Compared with the prior art, the utility model provides a displacement measurement device, mask platform measurement system and lithography machine have following advantage:

(1) because the utility model provides a displacement measurement device includes first direction displacement measurement subassembly and second direction displacement measurement subassembly, first direction and second direction mutually perpendicular, just first direction displacement measurement subassembly includes the relative grating and the read head that set up, second direction displacement measurement subassembly includes relative interferometer and the reflection element that sets up, from this, through first direction displacement measurement subassembly can return first direction displacement interference signal, through second direction displacement interference signal can be returned to second direction displacement measurement subassembly, the optical detection module is used for surveying first direction displacement interference signal with second direction displacement interference signal transmits for optical signal processing module, through optical signal processing module handles and can obtain first direction displacement and second direction displacement after calculating. Therefore, it is visible the utility model discloses an adopt the combination of one-dimensional grating and reflection element, can realize the measurement of the two-dimensional displacement volume of quilt measuring target such as work piece platform, motion platform, mask platform, not only with low costs, the performance is high, has wide angle adaptability moreover, and it is more convenient to use, wherein first direction displacement measurement subassembly can be used to the displacement measurement of the long stroke direction of quilt measuring target, second direction displacement measurement subassembly can be used to the displacement measurement of the long stroke direction of perpendicular to has increased the measurement perceptibility of perpendicular grating face direction, and this perpendicular grating face direction's measured data can be used for the compensation control of high accuracy.

(2) Because the utility model provides a mask platform measurement system includes at least a set of displacement measurement device that the aforesaid was said, and first direction displacement measurement component is used for measuring the displacement of mask platform along Y to, second direction displacement measurement component is used for measuring the displacement of mask platform along X to, from this, for original mask platform grating measurement system, the grating becomes one-dimensional by two-dimentional, can effectively reduce cost from this; compared with the original mask stage interferometer measuring system, the Y-direction interferometer with a very long optical path is removed, the grating which is less affected by temperature, pressure, humidity environment and the like is adopted for replacement, the measurement reproducibility index of the measuring system can be effectively improved, and the overall performance of the measuring system is further improved.

(3) Because the back surface of the grating is arranged on the side surface of the plate bearing table of the mask table, which is arranged along the Y direction, compared with the original mask table grating measuring system, the grating measuring system can reduce the increase of the volume and the mass of the grating and improve the mechanical property stability of the mask table.

(4) Because the utility model provides an among the mask platform measurement system, the read head install in the mask platform hold the version platform outlying, from this for original mask platform grating measurement system, can get rid of and hold the required read head space in version platform side below, effectively avoid holding version platform and read head to bump.

(5) For original mask platform grating measurement system, the utility model provides a required gas bath of light path sweeps the space and can not sheltered from by the grating among the mask platform measurement system, is convenient for the control of gas bath environment from this more. Furthermore, the utility model provides an optical path directly is in the mask face in the mask platform measurement system, does not have the abbe arm.

(6) Because the utility model provides a lithography machine, include as above displacement measurement device, from this, can realize the displacement measurement of the two dimension or the three-dimensional direction of motion platform, mask platform, work piece platform etc. through the one-dimensional grating.

Drawings

Fig. 1 is a schematic structural diagram of a displacement measuring device according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a first directional displacement measuring assembly according to an embodiment of the present invention;

FIG. 3a is a schematic structural diagram of a retroreflector according to a first embodiment of the present invention;

FIG. 3b is a schematic structural diagram of a retroreflector according to a second embodiment of the present invention;

FIG. 3c is a schematic structural diagram of a retroreflector according to a third embodiment of the present invention;

FIG. 3d is a schematic structural diagram of a retroreflector according to a fourth embodiment of the present invention;

fig. 3e is a schematic structural diagram of a retroreflector according to a fifth embodiment of the present invention;

fig. 3f is a schematic structural view of a retroreflector according to a sixth embodiment of the present invention;

FIG. 4 is a schematic diagram of a conventional mask stage grating measurement system;

FIG. 5 is a schematic diagram of a prior art mask stage interferometer measurement system;

fig. 6 is a schematic structural diagram of a mask stage measurement system according to an embodiment of the present invention.

Wherein the reference numbers are as follows:

a first directional displacement measurement assembly-100; second direction displacement measuring assembly-200; a first measuring beam-310, 320; a second measuring beam-400; gratings-110, 101, 102; read head-120, 1201, 1202; retroreflector-121, 122; interferometer-210, 211, 212, 213; a reflective element-220; first order diffracted light-311, 321; second order diffracted light-312, 322; a lens-130; a concave mirror-140; incident light-510; outgoing light-520; a transmissive grating-150; a reflecting prism-160; a plate bearing table-600; mask plane-610; a strip mirror-700; corner cube-810, 820.

Detailed Description

The displacement measuring device, the mask stage measuring system and the lithography machine according to the present invention will be described in further detail with reference to the accompanying drawings and the detailed description. The advantages and features of the present invention will become more apparent from the following description. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention. To make the objects, features and advantages of the present invention more comprehensible, please refer to the attached drawings. It should be understood that the structure, ratio, size and the like shown in the drawings attached to the present specification are only used for matching with the content disclosed in the specification, so as to be known and read by those skilled in the art, and are not used for limiting the limitation of the implementation of the present invention, so that the present invention does not have the essential significance in the technology, and any modification of the structure, change of the ratio relationship or adjustment of the size should still fall within the scope of the technical content disclosed in the present invention without affecting the function and the achievable purpose of the present invention.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "fixed" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The core thought of the utility model is to provide a displacement measurement device, mask platform measurement system and lithography machine to solve current displacement measurement device with high costs, the processing degree of difficulty is big, the light utilization rate is low and do not have wide angle adaptability scheduling problem.

To achieve the above-mentioned idea, the present invention provides a displacement measuring device, please refer to fig. 1 and fig. 2, wherein fig. 1 schematically shows a schematic structural diagram of the displacement measuring device according to an embodiment of the present invention; fig. 2 schematically shows a structural diagram of a first direction displacement measuring assembly 100 according to an embodiment of the present invention. As shown in fig. 1 and 2, the displacement measuring apparatus includes a light source (not shown), a first direction displacement measuring assembly 100, a second direction displacement measuring assembly 200, an optical detection module (not shown) and an optical signal processing module (not shown), wherein the first direction and the second direction are perpendicular to each other, the optical detection module is connected to the optical signal processing module, specifically, the optical detection module is connected to the optical signal processing module through an optical fiber, the optical detection module is configured to detect a first direction displacement interference signal and a second direction displacement interference signal, and the optical signal processing module is configured to calculate a first direction displacement according to the first direction displacement interference signal and calculate a second direction displacement according to the second direction displacement interference signal.

The light source is used for emitting a first measuring light beam and a second measuring light beam, and the first measuring light beam is divided into two beams.

Preferably, the light source comprises at least one laser, and the laser adopts any wavelength between 320 nm and 1500nm, such as 633nm, 780nm and 980 nm. And the laser is also provided with a wavelength monitoring system which is used for monitoring the change condition of the wavelength of the laser and compensating the wavelength. The laser can be a gas laser such as a He-Ne laser, and has the characteristics of narrow line width and high frequency stability. The first measuring beam and the second measuring beam may be emitted by the same laser or by different lasers.

As shown in FIGS. 1 and 2, the first direction displacement measurement assembly 100 includes a grating 110 and a read head 120 that are oppositely disposed; the reading head 120 includes a retroreflector 121 and a retroreflector 122 that are symmetrically disposed. The placement of the retroreflectors 121 and 122 needs to match the diffraction of the beams so that the diffracted beams of the first measuring beam 310 and the diffracted beams of the first measuring beam 320 at least partially overlap when they are reflected back to the grating 110 to form an effective diffraction interference shift signal.

As shown in fig. 2, the first measuring beam 310 is incident on the grating 110 through the reading head 120 and is diffracted on the surface of the grating 110 to generate a first diffracted beam 311, the first diffracted beam 311 is projected to the retroreflector 121 and is reflected back to the grating 110 through the retroreflector 121, and is diffracted twice on the surface of the grating 110 to generate a second diffracted beam 312. Similarly, the first measuring beam 320 is incident on the grating 110 through the reading head 120 and is diffracted on the surface of the grating 110 to generate a first diffracted beam 321, the first diffracted beam 321 is projected to the retroreflector 122 and is reflected back to the grating 110 through the retroreflector 122, and is diffracted twice on the surface of the grating 110 to generate a second diffracted beam 322, and the second diffracted

beams

312 and 322 are converged to form a first direction displacement interference signal; the first direction displacement interference signal is detected by the optical detection module and then transmitted to the optical signal processing module, and the optical signal processing module processes and calculates the first direction displacement interference signal to obtain a first direction displacement.

As shown in FIG. 2, the first diffracted light 311 diffracted by the first measuring beam 310 on the surface of the grating 110 is projected to a retroreflector 121, and is reflected back to the surface of the grating 110 by the retroreflector 121 to be diffracted for the second time, so as to generate a second diffracted light 312, the first diffracted light 321 diffracted by the first measuring beam 320 on the surface of the grating 110 is projected to a retroreflector 122, and is reflected back to the surface of the grating 110 by the retroreflector 122 to be diffracted for the second time, so as to generate a second diffracted light 322, and the second diffracted light 321 and the second diffracted light 322 are converged to form a first directional displacement interference signal.

Preferably, as shown in fig. 3a, in the first embodiment, the retroreflectors 121 and 122 are corner cube prisms. By using corner cube prisms as retroreflectors 121, 122, it is achieved that the incident light 510 and the outgoing light 520 are parallel to each other, opposite in direction, and offset by a certain distance.

Preferably, as shown in fig. 3b, in the second embodiment, the retroreflectors 121 and 122 are right-angle prisms. By using right-angle prisms as retroreflectors 121, 122, it is also possible to achieve that the incident light 510 and the outgoing light 520 are parallel to each other, in opposite directions, and offset by a certain distance.

Preferably, as shown in fig. 3c, in the third embodiment, the retroreflectors 121 and 122 are cat-eye reflectors. By using a cat-eye reflector as a retroreflector, it is also possible to achieve that the incident light 510 and the outgoing light 520 are parallel to each other, in opposite directions, and offset by a certain distance. As shown in fig. 3c, the cat-eye reflector comprises a lens 130 and a concave reflector 140, the center of the sphere of the concave reflector 140 coincides with the center of the lens 130, and the focal point of the lens 130 is located on the reflecting surface of the concave reflector 140. Therefore, the incident light 510 is converged on the concave reflector 140 by the lens 130, reflected by the concave reflector 140, and then emitted light 520 parallel to the incident light 510 but in the opposite direction through the lens 130.

Preferably, as shown in fig. 3d, in the fourth embodiment, the retroreflectors 121 and 122 are dove prisms. By using dove prisms as the retroreflectors 121, 122, it is also possible to realize that the incident light 510 and the emergent light 520 are parallel to each other, opposite in direction, and offset by a certain distance.

Preferably, as shown in fig. 3e, in the fifth embodiment, the retroreflectors 121 and 122 are hollow retroreflectors, and the hollow retroreflectors include three mutually perpendicular reflection surfaces, through which the incident light 510 and the emergent light 520 are parallel to each other, opposite in direction, and offset by a certain distance.

Preferably, as shown in fig. 3f, in the sixth embodiment, the retroreflector 121, 122 is a grating reflector, and the grating reflector includes a transmissive grating and a reflective prism. The incident light 510 is transmitted to the reflection prism by the transmission grating, is reflected to the transmission grating by the reflection prism, and is transmitted out the emergent light 520 which is parallel to the incident light 510 but has the opposite direction by the transmission grating.

As shown in fig. 1, the second directional displacement measurement assembly 200 includes an interferometer 210 and a reflective element 220 disposed opposite to each other; the second measuring beam 400 is incident on the reflection element 220 via the interferometer 210, reflected to the interferometer 210 via the reflection element 220, and forms a second directional displacement interference signal; the second direction displacement interference signal is detected by the optical detection module and then transmitted to the optical signal processing module, and the optical signal processing module processes and calculates the second direction displacement interference signal to obtain a second direction displacement.

Preferably, as shown in fig. 1, the reflecting element 220 is a long strip mirror, so that the reflecting element 220 can be further simplified by adopting the long strip mirror, and the overall structure of the displacement measuring device provided by the present invention can be further reduced in cost.

Preferably, as shown in fig. 1, the working surface of the grating 110 and the working surface of the reflective element 220 are located on the same plane. From this, this kind of setting can make the utility model provides a displacement measurement device structure is compacter. It should be noted that, as will be understood by those skilled in the art, in other embodiments, the working surface of the grating 110 and the working surface of the reflective element 220 may not be located on the same plane, and the positions of the grating 110 and the reflective element 220 may be set according to the positions of the first direction and the second direction, so long as the displacement in the first direction can be measured by the grating 110, and the displacement in the second direction can be measured by the reflective element 220.

Preferably, as shown in fig. 1, the length of the grating 110 is equal to the length of the elongated mirror, and the width of the grating 110 is equal to the width of the elongated mirror. From this, this kind of setting can further improve the utility model provides a displacement measurement device's wide angle adaptability.

Therefore, the utility model discloses an adopt the combination of one-dimensional grating 110 and reflection element 220, can realize the measurement of the two-dimensional displacement volume of the measured target such as work piece platform, motion platform, mask platform, not only with low costs, the performance is high, has wide angle adaptability moreover, and it is more convenient to use. The first direction displacement measurement assembly 100 can be used for displacement measurement in the long stroke direction of the measured target, and the second direction displacement measurement assembly 200 can be used for displacement measurement perpendicular to the long stroke direction, so that the measurement sensing capability in the direction perpendicular to the grating surface is increased, and the measurement data in the direction perpendicular to the grating surface can be used for high-precision compensation control.

Referring to fig. 4, which schematically shows a structural diagram of a mask stage grating measurement system in the prior art, as shown in fig. 4, the side surfaces of the

gratings

101 and 102 are bonded to the side surface of the mask stage 600, the working surfaces of the

gratings

101 and 102 are at the same height as the mask surface 610, and the working surfaces face down, and the read heads 1201 and 1202 are respectively located below the working surfaces of the

gratings

101 and 102. Since the working surface (diffraction surface) of the grating is at the same height as the mask surface 610 in the prior art, i.e. the diffraction surface of the grating is higher than the lower bottom surface of the mask table (i.e. the surface facing the workpiece table). Whereas +/-1 st order diffracted light used for grating measurement may be diffracted at an angle, when the diffraction surface of the grating is higher than the lower bottom surface of the mask stage, part of the diffracted light towards the mask stage may be blocked by the mask stage and may not return to the grating read head, resulting in signal loss. In order to solve the problem that the diffracted light beams are shielded by the mask table, a method of increasing the size of the grating surface of the grating and moving the working light spots on the grating surface outwards can be adopted. And increasing the grating surface size of the grating will inevitably lead to the increase of the whole area of the grating, which will inevitably bring about the increase of the volume and the quality of the grating, and since the

gratings

101 and 102 are adhered to the side surface of the plate bearing table 600 of the mask table, the increase of the volume and the quality of the grating will inevitably reduce the mechanical stability of the mask table.

Referring to fig. 5, which schematically shows a structural diagram of a conventional mask stage interferometer measuring system, as shown in fig. 5, a back surface of a strip mirror 700 is adhered to a side surface of a mask stage 600 of the mask stage, and a working surface of the strip mirror 700 faces to the outside of the side surface of the mask stage 600 and is opposite to an interferometer 211 for measuring displacement of the mask stage along the X direction.

Pyramid prisms

810, 820 are attached to the Y-direction side of the reticle stage 600 opposite the

interferometers

212, 213, respectively, for measuring the displacement of the reticle stage in the Y-direction. Because the measurement accuracy of the current interferometer almost reaches the limit, and meanwhile, the measurement accuracy of the interferometer is greatly influenced by the surrounding environment, the measurement repetition accuracy is not high (even if the environment is good, the measurement repetition accuracy can exceed 1nm), and the traditional interferometer measurement system is difficult to meet the requirement of further improving the alignment accuracy.

In order to solve the problems of the mask stage grating measurement system and the mask stage interferometer measurement system in the prior art, the present invention further provides a mask stage measurement system, please refer to fig. 6, which schematically shows a structural schematic diagram of the mask stage measurement system provided by an embodiment of the present invention, as shown in fig. 6, the mask stage measurement system includes at least one set of the displacement measurement device described above, the first direction displacement measurement component 100 is used for measuring the displacement of the mask stage along the Y direction, and the second direction displacement measurement component 200 is used for measuring the displacement of the mask stage along the X direction. The movement characteristics of the mask table are that the Y-direction movement stroke is long, and the X-direction movement stroke is short, so that the environment influence can be obviously reduced by adopting the grating measurement system in the Y direction with the longer movement stroke of the mask table, and the problem that the reproduction performance of the interferometer is difficult to improve due to the environment influence is avoided. Compared with the original mask table grating measuring system, the utility model provides a mask table measuring system, the grating changes into one-dimensional by two-dimentional, can effectively reduce cost from this; compared with the original mask stage interferometer measuring system, the Y-direction interferometer with a very long optical path is removed, the grating which is less affected by temperature, pressure, humidity environment and the like is adopted for replacement, the measurement reproducibility index of the measuring system can be effectively improved, and the overall performance of the measuring system is further improved.

Preferably, the back surface of the grating 110 and the back surface of the reflective element 220 are both mounted on the side surface of the reticle stage 600 disposed along the Y direction, that is, the working surface of the grating 110 and the working surface of the reflective element 220 are both disposed toward the X direction. Therefore, compared with the original mask stage grating measurement system, the volume and mass of the grating 110 can be reduced, and the mechanical performance stability of the mask stage is improved. Because the reading head is arranged opposite to the working surface of the grating 110, that is, the reading head is arranged at the periphery of the plate bearing table 600 of the mask table, compared with the original mask table grating measuring system, the reading head space required below the side surface of the plate bearing table 600 can be removed, and the collision between the plate bearing table 600 and the reading head is effectively avoided. Furthermore, the utility model provides an optical path directly is in mask face 610 in the mask platform measurement system, does not have the abbe arm, and the required gas bath of optical path sweeps the space and can not sheltered from by grating 110, the control of the gas bath environment of being convenient for more from this.

Preferably, the grating 110 and the reflective element 220 may be fixed to the mask table at the side of the stage 600 by means of bonding. In other embodiments, the grating 110 may be directly etched on the side of the stage 600.

Preferably, the mask stage measuring system comprises two sets of displacement measuring devices as described above, and the two sets of displacement measuring devices are respectively installed on two sides of the mask stage support 600. Therefore, the displacement measuring devices are arranged on the two sides of the mask table, so that two groups of displacement information in the X direction and the Y direction can be acquired simultaneously, and the mask table can be acquired along the X directionAnd displacement information in Y direction, and R of the mask table can be obtained_ZDisplacement information of (2). In addition, through setting up two sets of displacement measurement device, can also effectively improve displacement measurement's precision, effectively reduce the error.

In order to realize the above idea, the utility model also provides a lithography machine, lithography machine include the above displacement measurement device. Because the utility model provides a lithography machine, include as above displacement measurement device, from this, can realize the displacement measurement of the two dimension or the three-dimensional direction of motion platform, mask platform, work piece platform etc. through the one-dimensional grating.

In summary, compared with the prior art, the utility model provides a displacement measurement device, mask platform measurement system and lithography machine have following advantage:

(1) because the utility model provides a displacement measurement device includes first direction displacement measurement subassembly and second direction displacement measurement subassembly, first direction and second direction mutually perpendicular, just first direction displacement measurement subassembly includes the relative grating and the read head that set up, second direction displacement measurement subassembly includes relative interferometer and the reflection element that sets up, from this, through first direction displacement measurement subassembly can return first direction displacement interference signal, through second direction displacement interference signal can be returned to second direction displacement measurement subassembly, the optical detection module is used for surveying first direction displacement interference signal with second direction displacement interference signal transmits for optical signal processing module, through optical signal processing module handles and can obtain first direction displacement and second direction displacement after calculating. Therefore, it is visible the utility model discloses an adopt the combination of one-dimensional grating and reflection element, can realize the measurement of the two-dimensional displacement volume of quilt measuring target such as work piece platform, mask platform, not only with low costs, the performance is high, has wide angle adaptability moreover, and it is more convenient to use, wherein first direction displacement measurement subassembly can be used to the displacement measurement of quilt measuring target long stroke direction, second direction displacement measurement subassembly can be used to the displacement measurement of the long stroke direction of perpendicular to increased the measurement perceptibility of perpendicular grating face direction, this perpendicular grating face direction's measured data can be used for the compensation control of high accuracy.

(6) Because the utility model provides a lithography machine, include as above displacement measurement device, from this, can realize the displacement measurement of the two dimension or the three-dimensional direction of motion platform, mask platform, work piece platform through the one-dimensional grating.

The above description is only for the description of the preferred embodiments of the present invention, and not for any limitation of the scope of the present invention, and any modification and modification made by those skilled in the art according to the above disclosure are all included in the protection scope of the claims. It will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A displacement measuring device is characterized by comprising a light source, a first direction displacement measuring component, a second direction displacement measuring component, a light detection module and a light signal processing module, wherein the first direction and the second direction are perpendicular to each other;

the second measuring beam is incident to the reflecting element through the interferometer and reflected to the interferometer through the reflecting element to form a second direction displacement interference signal;

2. A displacement measuring device according to claim 1, wherein the reflecting element is an elongated mirror.

3. A displacement measuring device according to claim 2, wherein the working surface of the grating is in the same plane as the working surface of the reflective element.

4. The displacement measuring device of claim 1, wherein the retroreflector is a cube-corner prism, a right-angle prism, a cat-eye reflector, a dove prism, a hollow retroreflector, or a grating reflector.

5. The displacement measuring device of claim 4, wherein the cat-eye reflector comprises a lens and a concave reflector, the center of the sphere of the concave reflector coincides with the center of the lens, and the focal point of the lens is located on the reflecting surface of the concave reflector.

6. The displacement measuring device of claim 4, wherein the hollow retroreflector comprises three mutually perpendicular reflecting surfaces.

7. The displacement measuring device of claim 4, wherein the grating reflector comprises a transmissive grating and a reflective prism.

8. A mask stage measurement system comprising at least one set of displacement measuring devices according to any one of claims 1 to 7, wherein the first direction displacement measuring assembly is configured to measure a displacement of the mask stage in the Y-direction and the second direction displacement measuring assembly is configured to measure a displacement of the mask stage in the X-direction.

9. The reticle stage measurement system of claim 8, wherein a backside of the grating and a backside of the reflective element are both mounted on a side of the reticle stage disposed in the Y-direction.

10. The mask stage measurement system according to claim 8, comprising two sets of displacement measuring devices according to any one of claims 1 to 7, respectively mounted on both sides of a reticle stage of the mask stage.

11. A lithography machine, characterized in that it comprises a displacement measuring device according to any one of claims 1 to 7.