Alignment sensor optical module and alignment sensor

Abstract

The invention relates to the technical field of optical systems, and provides an alignment sensor optical module and an alignment sensor.The alignment sensor optical module comprises an illumination lens, a polarization beam splitter, an objective lens set, an interferometer and an output lens and further comprises a first angle-adjustable reflector and a second angle-adjustable reflector. The illumination light sequentially passes through the illumination lens, the first reflector, the polarization beam splitter and the objective lens group to be incident to the grating mark etched on the surface of the silicon wafer, and the grating mark is diffracted to obtain multi-level diffracted light; the multi-level diffracted light sequentially passes through an objective lens group and a polarization beam splitter to enter an interferometer, and the interferometer outputs two beams of interference light; and the two beams of interference light are output by the output lens after passing through the second reflector. According to the alignment sensor optical module, the interferometer is adopted to output two beams of interference light, and the problem caused by interference of multi-level diffraction light on an image plane is avoided. The alignment sensor optical module simplifies the use of an optical lens group, avoids the use of complex optical elements such as a wedge block array or a wedge plate group, and is low in operation difficulty and cost.

Description

Technical Field

[0001] The present invention relates to the technical field of optical systems, and in particular to an alignment sensor optical module and an alignment sensor. Background Art

[0002] Alignment technology is one of the key technologies of lithography machines, and its performance indicators directly affect the overall performance of the lithography machine. In the process of integrated circuit chip production, in order to achieve the expected accuracy indicators of the lithography machine, it is necessary to accurately establish the relationship between the various coordinate systems of the lithography machine so that the mask, mask stage, objective lens, silicon wafer, and workpiece stage can work in a unified calibration system. Therefore, it is necessary to align the mask with the silicon wafer.

[0003] The alignment between the mask and the silicon wafer can include coaxial mask alignment and off-axis silicon wafer alignment, that is, using the work stage to establish the positional relationship between the mask and the silicon wafer. The basic process of alignment is: first, the alignment between the mask and the work stage is achieved through the coaxial alignment system, that is, the positional relationship of the mask relative to the work stage is calculated, and then the alignment between the silicon wafer and the work stage is completed by the off-axis alignment system, that is, the positional relationship of the silicon wafer relative to the work stage is calculated, and then the alignment between the silicon wafer and the mask is indirectly achieved, and the positional relationship between the two is established to meet the overlay accuracy requirements.

[0004] In the off-axis alignment process, the position coordinates of the silicon wafer in the machine coordinate system and the position coordinates of the workpiece stage in the machine coordinate system are first measured, and then the position relationship of the silicon wafer relative to the workpiece stage is calculated. For the off-axis alignment system, the mainstream solution is to use the grating mark as the measurement reference, and use a wedge array or a wedge plate group to achieve the overlap and coherent imaging of the multi-order diffraction light of the grating mark, and separate the imaging space on the image plane; by detecting the transmitted light intensity of the grating mark image through the reference grating, a sinusoidal output alignment signal is obtained to determine whether it is aligned.

[0005] Since the multi-order diffracted light of the off-axis alignment system interferes on the image plane, when the reflectivity of the grating mark is uneven, the alignment error caused by factors such as mark rotation and magnification error is large. Moreover, when the off-axis alignment system uses a wedge array or a wedge plate group, the surface shape and wedge angle consistency of the two wedges of the same positive and negative refractive order are very high, and the processing, manufacturing, assembly and debugging requirements of the wedge array or the wedge plate group are also very high, which is difficult to operate and costly. Summary of the invention

[0006] The present invention provides an alignment sensor optical module and an alignment sensor, which are used to solve the defects in the prior art.

[0007] The present invention provides an alignment sensor optical module, comprising: an illumination lens, a polarization beam splitter, an objective lens group, an interferometer and an output lens, and also comprising a first reflector and a second reflector with adjustable angles;

[0008] The illumination light is incident on the grating mark etched on the surface of the silicon wafer through the illumination lens, the first reflector, the polarization beam splitter and the objective lens group in sequence, and the grating mark is diffracted to obtain multi-order diffracted light;

[0009] The multi-order diffracted light is incident on the interferometer through the objective lens group and the polarization beam splitter in sequence, and the interferometer outputs two beams of interference light;

[0010] The two interference lights are outputted by the output lens after passing through the second reflector.

[0011] An alignment sensor optical module provided according to the present invention further includes a compensator arranged on the output light path of the interferometer, for matching the phases of the two interference lights.

[0012] An alignment sensor optical module according to the present invention further comprises an integrated housing, wherein the integrated housing is provided with a plurality of cavities, which are respectively used to carry the illumination lens, the first reflector, the polarization beam splitter, the interferometer, the second reflector and the output lens;

[0013] Each cavity is provided with a through hole along the optical transmission direction of the supported object.

[0014] According to an alignment sensor optical module provided by the present invention, the objective lens group is an achromatic lens group;

[0015] The silicon wafer surface is located on the focal plane of the achromatic lens group.

[0016] An alignment sensor optical module provided according to the present invention further includes a multi-wavelength multiplexer and an output optical fiber;

[0017] The multi-wavelength multiplexer is used to receive the illumination light;

[0018] The output optical fiber is used to transmit the two beams of output light from the output lens.

[0019] The present invention also provides an alignment sensor, comprising: a laser generating device, an optical fiber coupler, an optical analog digital board and the alignment sensor optical module;

[0020] The laser generating device is used to generate multi-color laser;

[0021] The optical fiber coupler is used to couple the multi-color laser to obtain the illumination light;

[0022] The alignment sensor optical module is used to receive the illumination light and output two beams of output light;

[0023] The optical analog digital board is used to convert the two beams of output light into electrical signals and amplify the electrical signals to obtain target electrical signals; the target electrical signals are used to determine the position information of the grating mark.

[0024] According to an alignment sensor provided by the present invention, the laser generating device includes a supercontinuum light source, a filter module and a plurality of polarization-maintaining optical fibers;

[0025] The supercontinuum light source is used to generate continuous wavelength laser;

[0026] The filter module is used to filter out lasers of different wavelengths in the continuous wavelength laser;

[0027] The multiple polarization-maintaining optical fibers are used to output lasers of different wavelengths to obtain the multicolor lasers;

[0028] The alignment sensor further comprises a demultiplexer for decomposing two output beams of the alignment sensor optical module into different color bands;

[0029] The different color bands are converted into the electrical signals by the optical analog digital board.

[0030] According to an alignment sensor provided by the present invention, the laser generating device further comprises an attenuator and a control button corresponding to the attenuator;

[0031] The attenuator is used to control the intensity of the continuous wavelength laser.

[0032] According to an alignment sensor provided by the present invention, the fiber coupler and the alignment sensor optical module are connected via a first fiber connector, and / or the alignment sensor optical module and the demultiplexer are connected via a second fiber connector.

[0033] According to an alignment sensor provided by the present invention, at least one of the first optical fiber connector and the second optical fiber connector is configured with an interlocking device.

[0034] The present invention provides an alignment sensor optical module and an alignment sensor, wherein the alignment sensor optical module comprises: an illumination lens, a polarization beam splitter, an objective lens group, an interferometer and an output lens, and further comprises an angle-adjustable first reflector and a second reflector. The illumination light is incident on a grating mark etched on the surface of a silicon wafer through the illumination lens, the first reflector, the polarization beam splitter and the objective lens group in sequence, and the grating mark diffracts to obtain multi-order diffracted light; the multi-order diffracted light is incident on the interferometer through the objective lens group and the polarization beam splitter in sequence, and the interferometer outputs two beams of interference light; the two beams of interference light are output by the output lens after passing through the second reflector. The alignment sensor optical module uses an interferometer to output two beams of interference light, thereby avoiding the problem caused by the interference of multi-order diffracted light on the image plane. Moreover, the alignment sensor optical module simplifies the use of an optical lens group, avoids the use of complex optical elements such as a wedge array or a wedge plate group, and not only reduces the requirements for the processing, manufacturing, assembly and debugging of optical elements, reduces the difficulty and cost of operation, but also reduces the influence of optical element errors on the performance of the optical module. In addition, the alignment sensor optical module uses a first reflector and a second reflector with adjustable angles, which can simplify the assembly and debugging process of the optical module. The optical path structure is simple, easy to implement, and has wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on the drawings in the following description without paying any creative work.

[0036] Figure 1 is a structural schematic diagram of an alignment sensor optical module provided by the present invention;

[0037] Figure 2 is a schematic diagram of the optical path of the alignment sensor optical module provided by the present invention;

[0038] Figure 3 This is one of the structural schematic diagrams of the alignment sensor provided by the present invention;

[0039] Figure 4 This is the second structural schematic diagram of the alignment sensor provided by the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] The term "first" or "second" in the specification and claims of the present invention may include one or more of the features explicitly or implicitly. In the description of the invention, unless otherwise specified, "plurality" means two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the objects connected before and after are in an "or" relationship.

[0042] Since the multi-order diffracted light of the existing off-axis alignment system interferes on the image plane, when the reflectivity of the grating mark is uneven, the alignment error caused by factors such as mark rotation and magnification error is large. Moreover, when the off-axis alignment system uses a wedge array or a wedge plate group, the surface shape and wedge angle consistency of the two wedges of the same positive and negative refractive order are very high, and the processing, manufacturing, assembly and debugging requirements of the wedge array or the wedge plate group are also very high, which is difficult to operate and costly.

[0043] Based on this, an embodiment of the present invention provides an alignment sensor optical module for constructing an alignment sensor with a simple structure and easy implementation.

[0044] Figure 1 An alignment sensor optical module provided in an embodiment of the present invention, Figure 2 Schematic diagram of the optical path of the alignment sensor optical module provided in an embodiment of the present invention.

[0045] The alignment sensor optical module may include an illumination lens 3 , a polarization beam splitter 5 , an objective lens group 6 , an interferometer 7 , and an output lens 10 , and may also include a first reflector 4 and a second reflector 9 whose angles are adjustable.

[0046] The illumination light is incident on the grating mark etched on the surface 12 of the silicon wafer through the illumination lens 3, the first reflector 4, the polarization beam splitter 5 and the objective lens group 6 in sequence, and the grating mark diffracts to obtain multi-order diffracted light.

[0047] The multi-order diffracted light is incident on the interferometer 7 through the objective lens group 6 and the polarization beam splitter 5 in sequence, and the interferometer 7 outputs two interference light beams; the two interference light beams are output by the output lens 10 after passing through the second reflector 9.

[0048] Specifically, the alignment sensor optical module provided in the embodiment of the present invention includes an illumination lens 3, a first reflector 4, a polarization beam splitter 5, an objective lens group 6, an interferometer 7, a second reflector 9 and an output lens 10 arranged in sequence along the transmission direction of the illumination light. The positions and angles of the illumination lens 3, the polarization beam splitter 5, the objective lens group 6, the interferometer 7 and the output lens 10 are fixed. The positions of the first reflector 4 and the second reflector 9 are fixed, and the angles are adjustable. The angle here refers to the tilt angle in the horizontal plane.

[0049] The illumination light may be a multi-wavelength coupled optical signal. The illumination light is collimated by the illumination lens 3 to become collimated light and then incident on the first reflector 4. The illumination light is reflected by the first reflector 4 to the polarization beam splitter 5. The reflected light of the first reflector 4 is split on the splitting surface of the polarization beam splitter 5 and then projected to the objective lens group 6. The objective lens group 6 converges the incident light onto the grating mark etched on the surface of the silicon wafer, causing the grating mark to diffract and generate multi-order diffracted light.

[0050] Here, the silicon wafer can be placed on a work table. The grating mark is a grating structure, which can be a variety of different structures such as strips and crosses. The combination of the objective lens group 6 and the illumination lens 3 can form an image of the beam waist on the surface of the silicon wafer. The objective lens group 6 can be a lens group composed of a plurality of lenses. The objective lens group can be an achromatic lens group, which is used to ensure that the light beams incident on the grating marks on the surface of the silicon wafer converge to the same position to improve the quality of the light beam.

[0051] It is understandable that the spot sizes of the multi-order diffracted lights of different colors and the focal positions of the achromatic lens are slightly different due to the chromatic aberration effect. The silicon wafer surface can be located on the focal plane of the objective lens group, so that the imaging quality of the grating mark can be guaranteed.

[0052] By adjusting the angles between the reflecting surface of the first reflector 4 and the horizontal and vertical directions, the position and angle of the reflected light of the first reflector 4 can be adjusted in the horizontal and vertical directions, so that the reflected light of the first reflector 4 can be incident on the polarization beam splitter 5 at a correct angle.

[0053] The angle between the reflected light of the first reflector 4 and the normal of the first reflector 4 and the position of the objective lens group 6 can determine the telecentricity of the optical module of the alignment sensor.

[0054] The polarization beam splitter 5 may be a point mirror. The multi-order diffracted light is split by the polarization beam splitter 5 and then incident on the interferometer 7, which outputs two interference lights.

[0055] The interferometer 7 used here can be a Michelson interferometer, a Fizeau interferometer, a Twyman-Green interferometer, a Mach-Zehnder interferometer or a Fabry-Perot interferometer.

[0056] The optical input element of the interferometer 7 can be a polarization beam splitter, which can split the multi-order diffracted light into two beams of equal intensity and opposite polarization states after the beam splitting result of the polarization beam splitter 5, and transmit them along the movable arm and the stationary arm of the interferometer 7 respectively, and then output two interference lights of equal intensity and opposite polarization states through the optical output element.

[0057] The two interference light beams are reflected to the output lens 10 by the second reflector 9, and are focused and output by the output lens 10. By adjusting the angles between the reflection surface of the second reflector 9 and the horizontal and vertical directions, the position and angle of the reflected light of the second reflector 9 can be adjusted in the horizontal and vertical directions, so that the reflected light of the second reflector 9 can be accurately reflected to the output lens 10. The two output light beams aligned with the sensor optical module 34 can be obtained through the output lens 10. The two output light beams correspond to the two interference light beams one by one.

[0058] Since the two output light beams of the output lens 10 carry the grating mark information on the surface of the silicon wafer, the position information of the grating mark can be obtained by analyzing the two output light beams of the output lens 10, that is, the position coordinates of the silicon wafer in the machine coordinate system can be obtained, and then combined with the position coordinates of the workpiece stage in the machine coordinate system, the position relationship of the silicon wafer relative to the workpiece stage can be calculated, thereby indirectly realizing the alignment between the silicon wafer and the mask.

[0059] The alignment sensor optical module provided in the embodiment of the present invention includes: an illumination lens, a polarization beam splitter, an objective lens group, an interferometer and an output lens, and also includes a first reflector and a second reflector with adjustable angles. The illumination light is incident on the grating mark etched on the surface of the silicon wafer through the illumination lens, the first reflector, the polarization beam splitter and the objective lens group in sequence, and the grating mark diffracts to obtain multi-order diffracted light; the multi-order diffracted light is incident on the interferometer through the objective lens group and the polarization beam splitter in sequence, and the interferometer outputs two beams of interference light; the two beams of interference light are output by the output lens after passing through the second reflector. The alignment sensor optical module uses an interferometer to output two beams of interference light, avoiding the problem caused by the interference of multi-order diffracted light on the image plane. Moreover, the alignment sensor optical module simplifies the use of the optical lens group, avoids the use of complex optical elements such as wedge arrays or wedge plate groups, not only reduces the requirements for processing, manufacturing, assembly and debugging of optical elements, reduces the difficulty and cost of operation, but also reduces the impact of optical element errors on the performance of the optical module. In addition, the alignment sensor optical module uses a first reflector and a second reflector with adjustable angles, which can simplify the assembly and debugging process of the optical module. The optical path structure is simple, easy to implement, and has wide applicability.

[0060] On the basis of the above-mentioned embodiment, the alignment sensor optical module provided in the embodiment of the present invention further includes a compensator arranged on the output optical path of the interferometer, for matching the phases of the two interference lights.

[0061] Specifically, Figure 1 As shown, the alignment sensor optical module further includes a compensator 8 arranged on the output light path of the interferometer 7 .

[0062] Since the wavelengths of the two interfering lights output by the interferometer cannot be completely matched, in order to obtain interference suitable for all colors, a compensator is introduced. The compensator is used to generate a path length difference between the two interfering lights, effectively matching the phases of the two interfering lights, so that the modulation depth of all color signals is maximized when the two interfering lights are at zero optical path difference.

[0063] On the basis of the above embodiment, the alignment sensor optical module provided in the embodiment of the present invention further includes an integrated housing, wherein the integrated housing is provided with a plurality of cavities, which are respectively used to carry the illumination lens, the first reflector, the polarization beam splitter, the interferometer, the second reflector and the output lens;

[0064] Each cavity is provided with a through hole along the optical transmission direction of the supported object.

[0065] Specifically, Figure 1 As shown, the alignment sensor optical module further includes an integrated housing 1. The integrated housing 1 may be provided with a plurality of cavities, which are respectively used to carry the illumination lens 3, the first reflector 4, the polarization beam splitter 5, the interferometer 7, the second reflector 9 and the output lens 10. The compensator 8 on the output optical path of the interferometer 7 may be provided in the cavity where the interferometer 7 is located.

[0066] It is understandable that, in order to prevent the integrated housing from affecting the light beam transmission, each cavity in the integrated housing is provided with a through hole along the light path transmission direction of the object carried, namely, the illumination lens 3, the first reflector 4, the polarization beam splitter 5, the interferometer 7, the second reflector 9 or the output lens 10 carried in each cavity.

[0067] Adjustment knobs may be provided outside the cavities where the first reflector 4 and the second reflector 9 are located, respectively. By operating the adjustment knobs, the angles of the first reflector 4 and the second reflector 9 may be adjusted, respectively.

[0068] In the embodiment of the present invention, the integrated housing is introduced to avoid mutual influence between the optical paths of the optical elements in the optical module of the alignment sensor, thereby improving the accuracy of the output light.

[0069] Based on the above embodiment, the alignment sensor optical module provided in the embodiment of the present invention further includes a multi-wavelength multiplexer and an output optical fiber;

[0070] The multi-wavelength multiplexer is used to receive the illumination light;

[0071] The output optical fiber is used to transmit the two beams of output light from the output lens.

[0072] Specifically, Figure 1As shown, the alignment sensor optical module further includes a multi-wavelength multiplexer 2 and an output optical fiber 11. The multi-wavelength multiplexer 2 and the output optical fiber 11 can be arranged on the upper surface of the integrated housing 1.

[0073] The multi-wavelength multiplexer 2 is used to collimate and adjust the illumination light to obtain the collimated illumination light emitted perpendicularly to the multi-wavelength multiplexer 2 .

[0074] The output optical fiber 11 can be arranged on the upper surface of the integrated housing 1 through an output assembly. The output assembly may include a fixing device and a fine-tuning device, wherein the fixing device is used to fix the output optical fiber 11 on the upper surface of the integrated housing 1, and the fine-tuning device is used to make the light beam emitted from the output lens 10 hit the center of the output optical fiber 11.

[0075] The output optical fiber 11 can be used to transmit the two output lights of the output lens. The number of output optical fibers 11 can be two, one for transmitting each output light. The output optical fiber 11 can be connected to a software system, and the two output lights of the output lens are introduced into the software system, and the software system can calculate the position information of the grating mark using the two output lights of the output lens.

[0076] like Figure 3 As shown, based on the above embodiment, an alignment sensor is further provided in the embodiment of the present invention, and the alignment sensor includes a laser generating device 31, a fiber coupler 32, an optical analog digital board 33 and the above alignment sensor optical module 34.

[0077] The laser generating device 31 is used to generate multi-color laser light.

[0078] The optical fiber coupler 32 is used to couple multi-color lasers to obtain illumination light.

[0079] The alignment sensor optical module 34 is used to receive the illumination light and output two beams of output light.

[0080] The optical analog digital board 33 is used to convert the two output light beams of the alignment sensor optical module 34 into electrical signals, and amplify the electrical signals to obtain target electrical signals; the target electrical signals are used to determine the position information of the grating mark.

[0081] Specifically, in the alignment sensor provided in the embodiment of the present invention, the laser generating device 31, the fiber coupler 32, the alignment sensor optical module 34 and the optical analog digital board 33 may be connected via optical fibers.

[0082] The laser generating device 31 may be a laser box, and the multi-color laser may be 12-color light.

[0083] The multicolor laser can enter the alignment sensor optical module 34 through the fiber coupler 32. Here, the multicolor laser can be transmitted to the fiber coupler 32 through multiple different polarization-maintaining optical fibers, and the number of wavelengths of the multicolor laser is the same as the number of polarization-maintaining optical fibers. For example, 12 color lights can be connected to the fiber coupler 32 through 12 polarization-maintaining optical fibers, and the 12 color lights are coupled into a beam of light by the fiber coupler 32, and the beam of light is output by an optical fiber connected to the output end of the fiber coupler 32.

[0084] In particular, the optical fiber connected to the output end of the fiber coupler 32 can be connected to the input end of the multi-wavelength multiplexer in the alignment sensor optical module 34, so that a beam of light output from the output end of the fiber coupler 32 can be input into the alignment sensor optical module 34 as illumination light, and then two beams of output light of the alignment sensor optical module 34 can be obtained.

[0085] After that, the optical analog digital board 33 can receive the two beams of output light of the alignment sensor optical module 34, convert them into electrical signals, amplify the electrical signals and output them, and obtain the target electrical signals output by the optical analog digital board 33. The position information of the grating mark can be determined by the target electrical signals.

[0086] The alignment sensor provided in the embodiment of the present invention includes a laser generating device, an optical fiber coupler, an optical analog digital board, and the alignment sensor optical module provided in the above embodiments. The laser generating device is used to generate a multi-color laser. The multi-color laser is coupled by the optical fiber coupler to obtain an illumination light. The illumination light enters the alignment sensor optical module, and the alignment sensor optical module outputs two beams of output light. The optical analog digital board converts the two beams of output light of the alignment sensor optical module into electrical signals, and amplifies the electrical signals to obtain a target electrical signal for determining the position information of the grating mark. Due to the presence of the alignment sensor optical module, the structural complexity of the alignment sensor can be reduced, the alignment sensor can be simplified, and the alignment sensor can be easily implemented.

[0087] On the basis of the above-mentioned embodiment, in the alignment sensor provided in the embodiment of the present invention, the laser generating device comprises a supercontinuum light source, a filter module and a plurality of polarization-maintaining optical fibers;

[0088] The supercontinuum light source is used to generate continuous wavelength laser;

[0089] The filter module is used to filter out lasers of different wavelengths in the continuous wavelength laser;

[0090] The multiple polarization-maintaining optical fibers are used to output lasers of different wavelengths to obtain the multicolor lasers;

[0091] The alignment sensor further comprises a demultiplexer for decomposing two output beams of the alignment sensor optical module into different color bands;

[0092] The different color bands are converted into the electrical signals by the optical analog digital board.

[0093] Specifically, the laser generating device in the alignment sensor may include a supercontinuum light source, a filter module, and a plurality of polarization-maintaining optical fibers. The supercontinuum light source may generate continuous wavelength laser light, for example, the supercontinuum light source may be a white light source, and may generate full-band continuous laser light.

[0094] The optical filter module can filter out laser beams of different wavelengths from the continuous wavelength laser beam, for example, 12 laser beams of different wavelengths can be obtained.

[0095] Lasers of different wavelengths can be output through multiple polarization-maintaining optical fibers to obtain multi-color lasers.

[0096] Here, if Figure 3 As shown, the alignment sensor may further include a demultiplexer 35, which may be connected between the alignment sensor optical module 34 and the optical analog digital board 33 via an optical fiber, and is used to decompose the two beams of output light of the alignment sensor optical module 34 into different color bands. For example, the demultiplexer may decompose the two beams of output light of the alignment sensor optical module into four different color bands.

[0097] Finally, each different color band is converted into an electrical signal by the optical analog digital board 33.

[0098] On the basis of the above embodiment, in the alignment sensor provided in the embodiment of the present invention, the laser generating device further includes an attenuator and a control button corresponding to the attenuator;

[0099] The attenuator is used to control the intensity of the continuous wavelength laser.

[0100] Specifically, a shutter for controlling an attenuator may be built into the laser generating device, and the shutter may be controlled by a control button. The intensity of the continuous wavelength laser may be controlled by the attenuator to ensure that the intensity requirement of the continuous wavelength laser is met by the user.

[0101] On the basis of the above embodiments, in order to avoid the disadvantage of using a single optical fiber to transmit optical signals between optical devices, the alignment sensor provided in the embodiments of the present invention can be connected between the optical fiber coupler 32 and the alignment sensor optical module 34 through a first optical fiber connector 36, and the alignment sensor optical module 34 and the demultiplexer 35 can be connected through a second optical fiber connector 37.

[0102] like Figure 4As shown, the fiber coupler 32 and the alignment sensor optical module 34 can be connected by two sections of optical fiber through a first optical fiber connector 36, and the alignment sensor optical module 34 and the demultiplexer 35 can be connected by two sections of optical fiber through a second optical fiber connector 37, which can facilitate user operation and reduce operating difficulty.

[0103] On the basis of the above embodiment, in the alignment sensor provided in the embodiment of the present invention, at least one of the first optical fiber connector and the second optical fiber connector is configured with an interlocking device.

[0104] Specifically, since lasers have harmful radiation, the optical fiber connectors connected to the optical fiber couplers need to be configured with an interlocking device to prevent eye damage caused by leaked laser light when any optical fiber connector is accidentally unplugged.

[0105] Similarly, to prevent leaked laser from damaging eyes, the optical fiber connector connected to the sensor optical module can be configured with an interlocking device. When the optical fiber connector of the sensor optical module is accidentally pulled out, the laser generating device is controlled not to generate multi-color laser.

[0106] Since the purpose of the demultiplexer is to decompose the two output beams of the alignment sensor optical module into different color bands, the optical input level on the demultiplexer is considered dangerous. Therefore, the fiber optic connector connected to the input end of the demultiplexer can be configured with an interlock device. Since the fiber optic connector at the output end of the demultiplexer is a hanging type, an interlock device is not required.

[0107] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0108] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An alignment sensor optical module, characterized in that: include: The illumination lens, polarization beam splitter, objective lens group, interferometer and output lens also include a first reflector and a second reflector with adjustable angles; The illumination light is incident on the grating mark etched on the surface of the silicon wafer through the illumination lens, the first reflector, the polarization beam splitter and the objective lens group in sequence, and the grating mark is diffracted to obtain multi-order diffracted light; The multi-order diffracted light is incident on the interferometer through the objective lens group and the polarization beam splitter in sequence, and the interferometer outputs two beams of interference light; The two interference lights are outputted by the output lens after passing through the second reflector.

2. The alignment sensor optical module according to claim 1, characterized in that: It also includes a compensator arranged on the output light path of the interferometer, which is used to match the phases of the two interference lights.

3. The alignment sensor optical module according to claim 1, characterized in that: It also includes an integrated housing, wherein the integrated housing is provided with a plurality of cavities, which are respectively used to carry the illumination lens, the first reflector, the polarization beam splitter, the interferometer, the second reflector and the output lens; Each cavity is provided with a through hole along the optical transmission direction of the supported object.

4. The alignment sensor optical module according to claim 1, characterized in that: The objective lens group is an achromatic lens group; The silicon wafer surface is located on the focal plane of the achromatic lens group.

5. The alignment sensor optical module according to any one of claims 1 to 4, characterized in that: Also includes a multi-wavelength multiplexer and output optical fiber; The multi-wavelength multiplexer is used to receive the illumination light; The output optical fiber is used to transmit the two beams of output light from the output lens.

6. An alignment sensor, characterized in that: include: A laser generating device, a fiber coupler, an optical analog digital board, and an alignment sensor optical module as claimed in any one of claims 1 to 5; The laser generating device is used to generate multi-color laser; The optical fiber coupler is used to couple the multi-color laser to obtain the illumination light; The alignment sensor optical module is used to receive the illumination light and output two beams of output light; The optical analog digital board is used to convert the two beams of output light into electrical signals and amplify the electrical signals to obtain target electrical signals; the target electrical signals are used to determine the position information of the grating mark.

7. The alignment sensor according to claim 6, characterized in that The laser generating device comprises a supercontinuum light source, a filter module and a plurality of polarization-maintaining optical fibers; The supercontinuum light source is used to generate continuous wavelength laser; The filter module is used to filter out lasers of different wavelengths in the continuous wavelength laser; The multiple polarization-maintaining optical fibers are used to output lasers of different wavelengths to obtain the multicolor lasers; The alignment sensor further comprises a demultiplexer for decomposing two output beams of the alignment sensor optical module into different color bands; The different color bands are converted into the electrical signals by the optical analog digital board.

8. The alignment sensor according to claim 7, characterized in that The laser generating device further comprises an attenuator and a control button corresponding to the attenuator; The attenuator is used to control the intensity of the continuous wavelength laser.

9. The alignment sensor according to claim 7, characterized in that: The fiber coupler is connected to the alignment sensor optical module via a first fiber connector, and / or the alignment sensor optical module is connected to the demultiplexer via a second fiber connector.

10. The alignment sensor according to claim 9, characterized in that At least one of the first optical fiber connector and the second optical fiber connector is configured with an interlocking device.

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