Position measuring system for micropositioner

Abstract

The invention provides a micropositioner position measuring system. The micropositioner position measuring system comprises a light source module, wherein the light source module generates an annular Gaussian beam and emits the annular Gaussian beam to a position measuring module; the position measurement module responds to the received annular Gaussian beam, generates a corresponding photo-generated current signal, carries out voltage conversion processing on the photo-generated current signal, obtains voltage data and sends the voltage data to the position calculation module; the position calculation module determines the position information of the micropositioner relative to the coarse positioner based on the voltage data corresponding to each micropositioner position detection device. The light source module and the position measurement module are integrally connected, the integration complexity of the micropositioner position measurement system is reduced, the position of the micropositioner is determined based on detection data of different micropositioner position detection devices, and the precision is improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing and precision machining technology, and in particular to a micro-motion stage position measurement system. Background Art

[0002] With the rapid development of modern industrial technology, in the semiconductor manufacturing process, the motion control accuracy of the workpiece stage directly determines the accuracy of wafer exposure. This improvement in accuracy can not only improve the design rule size of the chip, but also further improve the yield and reduce production costs. The structure of the workpiece stage is usually composed of a coarse motion stage and a fine motion stage. The coarse motion stage is mainly responsible for rapid movement within a larger range to meet the needs of global positioning, while the fine motion stage is responsible for extremely high-precision small-range movement to compensate for small errors and achieve nanometer-level precise adjustment. Therefore, the position measurement system of the fine motion stage requires not only accuracy, but also rapid response, stability and anti-interference capabilities during high-speed movement of the fine motion stage.

[0003] In recent years, the method of measuring the position of the micro-motion stage based on optical sensors has been widely used due to its non-contact, high precision and fast response characteristics. However, this measurement method is limited by the accuracy of the position sensor and has limited effect on suppressing interference from complex environments. This method often requires complex hardware support, which increases the complexity of system integration. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide at least a micro-stage position measurement system, which reduces the integration complexity of the micro-stage position measurement system by integrating the light source module and the position measurement module, and determines the micro-stage position based on the detection data of different micro-stage position detection devices to improve the accuracy.

[0005] This application mainly includes the following aspects:

[0006] In a first aspect, an embodiment of the present application provides a micro-motion stage position measurement system, which includes multiple micro-motion stage position detection devices and a position calculation module, each micro-motion stage position detection device includes a light source module and a position measurement module arranged opposite to each other, the light source module is connected to the position detection module via a flexible circuit board corresponding thereto, the light source module of each micro-motion stage position detection device is installed at a different given position of the micro-motion stage, and the position detection module is installed on the coarse motion stage, wherein for each micro-motion stage position detection device: the light source module generates an annular Gaussian light beam and is incident on the position measurement module; the position measurement module generates a corresponding photogenerated current signal in response to the received annular Gaussian light beam, and performs voltage conversion processing on the photogenerated current signal to obtain voltage data and send it to the position calculation module; the position calculation module determines the position information of the micro-motion stage relative to the coarse motion stage based on the voltage data corresponding to each micro-motion stage position detection device.

[0007] In a possible implementation, the micro-stage position measurement system further includes an analog-to-digital conversion module. The light source module includes a light source and a collimating lens. The position measurement module includes a two-dimensional position sensitive detector and a board unit connected to each other. The light source is connected to the board unit through its corresponding flexible circuit board. After the board unit and the two-dimensional position sensitive detector are fixed, they are installed on the coarse stage. The light source module and the corresponding two-dimensional position sensitive detector are arranged opposite to each other. A light-shielding cover is installed on the two-dimensional position sensitive detector. The two-dimensional position sensitive detector is square. The center points of the four sides of the P layer of the two-dimensional position sensitive detector are respectively connected to the corresponding output electrodes. The board unit drives the light source and the two-dimensional position sensitive detector. Among them, for each micro-stage position detection device: the light emitted by the light source driven by the board power supply becomes an annular Gaussian beam through the collimating lens and then enters the corresponding effective detection area of the two-dimensional position sensitive detector, and an incident light spot is formed in the effective detection area; the two-dimensional position sensitive detector responds to the incident annular Gaussian beam, generates corresponding photocurrent signals at each output electrode and outputs them to the board unit; the board unit performs voltage conversion processing on the photocurrent signals generated by each output electrode, obtains the voltage data corresponding to the micro-stage position detection device and sends it to the analog-to-digital conversion module; the analog-to-digital conversion module performs analog-to-digital conversion processing on the voltage data, obtains the target voltage data and inputs it into the position calculation module; the position calculation module determines the position information of the micro-stage relative to the coarse stage based on the target voltage data corresponding to each micro-stage position detection device.

[0008] In a possible implementation, the board unit includes a transimpedance amplification component, a differential amplification component, and a voltage summation component. The output electrodes include two output cathodes oppositely arranged in the horizontal direction and two output anodes oppositely arranged in the vertical direction of the two-dimensional position-sensitive detector. The voltage data includes the horizontal differential voltage corresponding to the two output cathodes, the vertical differential voltage corresponding to the two output anodes, and the target debiasing voltage. The target debiasing voltage is the debiased horizontal differential voltage output by the two output cathodes or the debiased vertical differential voltage output by the two output anodes. Among them, for each micro-stage position detection device: the transimpedance amplification component receives the photocurrent signals from the respective output electrodes on the corresponding two-dimensional position-sensitive detector, and after processing, converts them into voltage processing signals corresponding to each output electrode and inputs them into the corresponding differential amplification component; the transimpedance amplification component inputs the voltage processing signals corresponding to the two output cathodes or the voltage processing signals corresponding to the two output anodes into the corresponding voltage summation component; the differential amplification component outputs the horizontal differential voltage corresponding to the two output cathodes and the vertical differential voltage corresponding to the two output anodes to the analog-to-digital conversion module based on the voltage processing signals corresponding to each output electrode; the voltage summation component outputs the target debiasing voltage to the analog-to-digital conversion module based on the voltage processing signals corresponding to the two output cathodes or the voltage processing signals corresponding to the two output anodes; after the analog-to-digital conversion module performs analog-to-digital conversion processing on the horizontal differential voltage, the vertical differential voltage, and the target debiasing voltage, it outputs the horizontal processing voltage, the vertical processing voltage, and the debiasing summation voltage to the position calculation module; the position calculation module for each micro-stage position detection device: determines the two-dimensional position information of the incident light spot generated by the light source module on the two-dimensional position-sensitive detector relative to the coarse stage according to the horizontal processing voltage, the vertical processing voltage, and the debiasing summation voltage; the position calculation module obtains the position information of the micro-stage relative to the coarse stage after resolving through the position measurement resolution matrix based on the two-dimensional position information corresponding to each micro-stage position detection device.

[0009] In a possible implementation, the transimpedance amplification component includes a transimpedance amplification circuit connected correspondingly to each output electrode. The transimpedance amplification circuit includes a current-to-voltage structure and a bias current compensation structure. Wherein, for the transimpedance amplification circuit: if the transimpedance amplification circuit is connected to the output cathode, one end of the bias current compensation structure is connected to a given single power supply; if the transimpedance amplification circuit is connected to the output anode, one end of the bias current compensation structure is grounded; the other end of the bias current compensation structure is respectively connected to the inverting input end of the current-to-voltage structure and the output electrode corresponding to the two-dimensional position sensitive detector. The non-inverting input end of the current-to-voltage structure is connected to the common-mode voltage, and the output end of the current-to-voltage structure is connected to the differential amplification component as the output end of the transimpedance amplification circuit; the common-mode voltage includes a first common-mode voltage and a second common-mode voltage. If the transimpedance amplification circuit is connected to the output cathode, the non-inverting input end of the current-to-voltage structure corresponding to the transimpedance amplification circuit is connected to the first common-mode voltage; if the transimpedance amplification circuit is connected to the output anode, the non-inverting input end of the current-to-voltage structure corresponding to the transimpedance amplification circuit is connected to the second common-mode voltage.

[0010] In a possible implementation, the differential amplification component includes an anode differential amplification circuit corresponding to the output anode and a cathode differential amplification circuit corresponding to the output cathode. Wherein, the first input end of the anode differential amplification circuit is connected to the output end of the transimpedance amplification circuit corresponding to one of the output anodes corresponding to the two-dimensional position sensitive detector. The second input end of the anode differential amplification circuit is connected to the output end of the transimpedance amplification circuit corresponding to the other input anode corresponding to the two-dimensional position sensitive detector. The common-mode voltage input end of the anode differential amplification circuit is connected to the third common-mode voltage. The positive differential output end and the negative differential output end of the anode differential amplification circuit are respectively connected to the analog-to-digital conversion module. The positive differential output end and the negative differential output end of the anode differential amplification circuit respectively output the vertical differential voltage corresponding to the two output anodes on the two-dimensional position sensitive detector; the first input end of the cathode differential amplification circuit is connected to the output end of the transimpedance amplification circuit corresponding to one of the input cathodes corresponding to the two-dimensional position sensitive detector. The second input end of the cathode differential amplification circuit is connected to the output end of the transimpedance amplification circuit corresponding to the other input cathode corresponding to the two-dimensional position sensitive detector. The common-mode voltage input end of the cathode differential amplification circuit is connected to the output end of the third common-mode voltage. The positive differential output end and the negative differential output end of the cathode differential amplification circuit are respectively connected to the analog-to-digital conversion module. The anode differential output end and the cathode differential output end of the cathode differential amplification circuit respectively output the horizontal differential voltage corresponding to the two output cathodes on the two-dimensional position sensitive detector.

[0011] In a possible implementation, the differential amplification circuit includes a first voltage-dividing resistor, a second voltage-dividing resistor, a third voltage-dividing resistor, a fourth voltage-dividing resistor, and a differential amplification structure. The first voltage-dividing resistor and the third voltage-dividing resistor have the same specifications, and the second voltage-dividing resistor and the fourth voltage-dividing resistor have the same specifications. Wherein, one end of the first voltage-dividing resistor is used as the first input terminal of the differential amplification circuit, the other end of the first voltage-dividing resistor is connected to one end of the second voltage-dividing resistor and the inverting input terminal of the differential amplification structure, and the other end of the second voltage-dividing resistor is connected to one of the output terminals of the differential amplification structure and then used as the positive differential output terminal of the differential amplification circuit; one end of the third voltage-dividing resistor is used as the second input terminal of the differential amplification circuit, the other end of the third voltage-dividing resistor is connected to one end of the fourth voltage-dividing resistor and the non-inverting input terminal of the differential amplification structure, and the other end of the fourth voltage-dividing resistor is connected to the other output terminal of the differential amplification structure and then used as the negative differential output terminal of the differential amplification circuit; the common-mode voltage input terminal of the differential amplification circuit is connected to the third common-mode voltage.

[0012] In a possible implementation, the board card module further includes a common-mode voltage generation circuit. The common-mode voltage generation circuit includes a first common-mode voltage-dividing structure, a second common-mode voltage-dividing structure, a third common-mode voltage-dividing structure, a fourth common-mode voltage-dividing structure, and a fifth common-mode voltage-dividing structure. Wherein, one end of the first common-mode voltage-dividing structure is connected to one end of the second common-mode voltage-dividing structure and used as the first common-mode power output terminal, the other end of the second common-mode voltage-dividing structure is respectively connected to one end of the third common-mode voltage-dividing structure and the ground, the other end of the third common-mode voltage-dividing structure is connected to one end of the fourth common-mode voltage-dividing structure and used as the second common-mode power output terminal, the other end of the fourth common-mode voltage-dividing structure is connected to one end of the fifth common-mode voltage-dividing structure and used as the third common-mode power output terminal, and the other end of the fifth common-mode voltage-dividing structure is connected to the other end of the first common-mode voltage-dividing structure and then connected to a given single power supply.

[0013] In a possible implementation, the voltage summing component includes a non-inverting summing structure, an inverting feedback structure, and a differential processing structure. The feedback generated by the non-inverting summing structure is equal to the feedback generated by the inverting feedback structure. Wherein, the first connection terminal and the second connection terminal of the non-inverting summing structure are respectively connected to the output terminals of the transimpedance amplification circuits corresponding to two output cathodes or the output terminals of the transimpedance amplification circuits corresponding to two output anodes, and the output terminal of the non-inverting summing structure is connected to the non-inverting input terminal of the differential processing structure; the first connection terminal of the inverting feedback structure is connected to a given single power supply, the second connection terminal of the inverting feedback structure is grounded, and the output terminal of the inverting feedback structure is connected to the inverting input terminal of the differential processing structure; the positive differential output terminal and the negative differential output terminal of the differential processing structure are connected to the analog-to-digital conversion module, and the positive differential output terminal and the negative differential output terminal of the differential processing structure output a target debiased voltage to the analog-to-digital conversion module.

[0014] In a possible implementation, the board unit further includes a photoelectric current servo circuit and a light source driving circuit. The light source is connected to the light source driving circuit through a flexible circuit board. The light source driving circuit includes a feedback circuit, a current regulating circuit, and a light source voltage stabilizing circuit. Among them, the inverting input terminal of the light source current servo circuit is connected to the positive output terminal or the negative output terminal of the voltage summing component. The non-inverting input terminal of the light source current servo circuit is connected to the cathode of the light source. The output terminal of the light source current servo circuit is connected to the input terminal of the feedback circuit. The output terminal of the feedback circuit is respectively connected to the regulating signal feedback terminal of the current regulating circuit and the cathode of the light source. The power supply terminal of the current regulating circuit is connected to a given single power supply. The output terminal of the current regulating circuit is connected to the anode of the light source. The light source voltage stabilizing circuit is connected in parallel between the anode and the cathode of the light source component.

[0015] In a possible implementation, the position calculation module determines the two-dimensional position information of the incident light spot corresponding to each micro-stage position detection device through the following formula:

[0016]

[0017] In this formula, X m represents the horizontal position of the incident light spot generated on the two-dimensional position sensitive detector relative to the center point of the two-dimensional position sensitive detector. Y m represents the vertical position of the incident light spot generated on the two-dimensional position sensitive detector relative to the center point of the two-dimensional position sensitive detector. V sum_pure represents the debiased summing voltage output by the analog-to-digital conversion module. V xF represents the horizontal processing voltage output by the analog-to-digital conversion module. V yF represents the vertical processing voltage output by the analog-to-digital conversion module; V xP represents the horizontal differential voltage output by the positive differential output terminal of the cathode differential amplifier circuit. V xN represents the horizontal differential voltage output by the negative differential output terminal of the cathode differential amplifier circuit. V yP represents the vertical differential voltage output by the positive differential output terminal of the anode differential amplifier circuit. V yN represents the vertical differential voltage output by the negative differential output terminal of the anode differential amplifier circuit. V sum_pure_p represents the voltage output by the positive differential output terminal of the voltage summing component. V sum_pure_N represents the voltage output by the negative differential output terminal of the voltage summing component, V xF 、V yF and V sum_pure are output by the analog-to-digital conversion module.

[0018] In a possible implementation manner, the position calculation module determines the position information of the micro-stage relative to the macro-stage in the following way: obtaining the spatial position information of the light source in each micro-stage position detection device in the spatial coordinate system with the center of the micro-stage as the origin coordinate; based on the spatial position information corresponding to each micro-stage position detection device, establishing a position measurement solution matrix, where the position measurement solution matrix describes the solution relationship between the two-dimensional position information corresponding to multiple micro-stage position detection devices and the six-degree-of-freedom position information of the micro-stage relative to the macro-stage; according to the position measurement solution matrix and the two-dimensional position information corresponding to each micro-stage position detection device, determining the six-degree-of-freedom position information of the micro-stage relative to the macro-stage.

[0019] A micro-stage position measurement system provided by an embodiment of the present application includes: a light source module that generates an annular Gaussian beam and irradiates it onto a position measurement module; the position measurement module responds to the received annular Gaussian beam, generates a corresponding photocurrent signal, and performs voltage conversion processing on the photocurrent signal to obtain voltage data and send it to the position calculation module; the position calculation module determines the position information of the micro-stage relative to the macro-stage based on the voltage data corresponding to each micro-stage position detection device. By integrally connecting the light source module and the position measurement module in the present application, the integration complexity of the micro-stage position measurement system is reduced, and the position of the micro-stage is determined based on the detection data of different micro-stage position detection devices, improving the accuracy.

[0020] To make the above objects, features, and advantages of the present application more obvious and understandable, the following specific preferred embodiments are given in conjunction with the accompanying drawings and described in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 Shows the overall structural schematic diagram of a micro-stage position measurement system provided by an embodiment of the present application;

[0023] Figure 2 Shows the overall structural schematic diagram of a micro-stage position detection device provided by an embodiment of the present application;

[0024] Figure 3 Shows the structural schematic diagram of a two-dimensional position sensitive detector provided by an embodiment of the present application;

[0025] Figure 4Shows the schematic diagram of a two-dimensional position sensitive detector provided by an embodiment of the present application;

[0026] Figure 5 Shows the structural schematic diagram of a board card unit provided by an embodiment of the present application;

[0027] Figure 6 Shows the structural schematic diagram of a transimpedance amplification component provided by an embodiment of the present application;

[0028] Figure 7 Shows the structural schematic diagram of a transimpedance amplification circuit provided by an embodiment of the present application;

[0029] Figure 8 Shows the structural schematic diagram of a common-mode voltage generation circuit provided by an embodiment of the present application;

[0030] Figure 9 Shows the structural schematic diagram of a differential amplification component provided by an embodiment of the present application;

[0031] Figure 10 Shows the structural schematic diagram of a differential amplification circuit provided by an embodiment of the present application;

[0032] Figure 11 Shows the structural schematic diagram of a voltage summing component provided by an embodiment of the present application;

[0033] Figure 12 Shows the structural schematic diagram of a light source driving connection provided by an embodiment of the present application. Detailed implementation manners

[0034] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It should be understood that the accompanying drawings in the present application are only for the purpose of illustration and description, and are not used to limit the protection scope of the present application. In addition, it should be understood that the schematic drawings are not drawn in actual proportions. The flowcharts used in the present application show operations implemented according to some embodiments of the present application. It should be understood that the operations in the flowchart may not be implemented in sequence, and steps without logical context relationships may be reversed or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart or remove one or more operations from the flowchart under the guidance of the content of the present application.

[0035] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all embodiments. The components of the embodiments of the present application described and illustrated in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application claimed, but only represents the selected embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0036] The prior art proposes a method of arranging a ring-shaped distribution of targets (including vertical and horizontal directions) on the stator of the control motor corresponding to the microstage, and configuring corresponding position sensors on the stator, and realizing the position detection of the microstage through the combination of the targets and the sensors. However, the measurement accuracy of this method is limited by the accuracy of the position sensors, and at the same time, the suppression effect on complex environmental interference is limited, and the ring-shaped layout design has high requirements for installation accuracy, increasing the complexity of system integration.

[0037] In recent years, the measurement method based on optical sensors has been widely used due to its non-contact, high-precision and fast response characteristics. This method utilizes the high-resolution characteristics of the optical system and combines signal processing technology to achieve precise displacement detection. For example, Patent 201810399665.2 proposes a multi-beam synchronous two-dimensional position detection method based on PSD (Position Sensitive Detector), which uses a double heterodyne asynchronous demodulation algorithm to demodulate a mixed signal with multiple frequencies superimposed and restore it to the two-dimensional position of the light spot. However, this technical solution requires precise frequency control and complex hardware support, and the cost and complexity of the system are relatively high. In addition, light intensity attenuation may cause difficulty in signal extraction, thereby affecting the measurement accuracy.

[0038] Based on this, the embodiments of the present application provide a microstage position measurement system. The present application reduces the integration complexity of such a microstage position measurement system by integrally connecting a light source module and a position measurement module, and determines the position of the microstage based on the detection data of different microstage position detection devices, improving the accuracy, specifically as follows:

[0039] Please refer to Figure 1 , Figure 1 which shows the overall structural schematic diagram of a microstage position measurement system provided by the embodiments of the present application. Please refer to Figure 2 , Figure 2 which shows the overall structural schematic diagram of a microstage position detection device provided by the embodiments of the present application. As Figure 1 and Figure 2As shown, the microstage position measurement system provided by the present application includes a plurality of microstage position detection devices 1, a position calculation module 2, and an analog-to-digital conversion module 3. Each microstage position detection device 1 includes a light source module 11 and a position measurement module 12 arranged opposite to each other. The light source module 11 is connected to the position detection module through its corresponding flexible circuit board 13. The light source module 11 of each microstage position detection device 1 is installed at different given positions of the microstage, and the position measurement module 12 of each microstage position detection device 1 is installed on the coarse stage. The flexible circuit board 13 of the present application is pre-customized and can realize the electrical connection between the light source module 11 and the position detection module.

[0040] In a preferred embodiment, for each microstage position detection device 1: The light source module 11 generates an annular Gaussian beam and irradiates it onto the position measurement module 12. The position measurement module 12 generates a corresponding photocurrent signal in response to the received annular Gaussian beam, performs voltage conversion processing on the photocurrent signal to obtain voltage data, and sends the voltage data to the analog-to-digital conversion module 3. The analog-to-digital conversion module 3 processes the voltage data output by each microstage position detection device 1 and then sends it to the position calculation module 2. The position calculation module 2 determines the position information of the microstage relative to the coarse stage based on the processed voltage data corresponding to each microstage position detection device 1.

[0041] In a preferred embodiment, the light source module 11 includes a light source and a collimating lens (not shown in the figure). The light source can be a light-emitting diode, such as Figure 2 As shown, the position measurement module 12 includes a two-dimensional position-sensitive detector 120 and a board unit 121 connected to each other. For each microstage position detection device 1, the light source module 11 is connected to the board unit 121 through its corresponding flexible circuit board 13. The board unit 121 is installed on the coarse stage. The light source module 11 and the corresponding two-dimensional position-sensitive detector 120 are arranged opposite to each other. The two-dimensional position-sensitive detector 120 is a two-dimensional PSD (Position Sensitive Detector), and the two-dimensional position-sensitive detector 120 is fixed to the board unit 121.

[0042] In the present application, to avoid the influence of ambient light, a light-shielding cover is installed on the two-dimensional position-sensitive detector 120 to shield most of the ambient light, and as much as possible, the annular Gaussian beam emitted by the light source module 11 is irradiated within the effective detection area of the two-dimensional position-sensitive detector 120.

[0043] The board unit 121 drives the light source in the corresponding light source module 11 and the two-dimensional position-sensitive detector 120.

[0044] Please refer to Figure 3 , Figure 3 shows a schematic structural diagram of a two-dimensional position-sensitive detector provided by an embodiment of the present application. Please refer toFigure 4 , Figure 4 shows the schematic diagram of a two-dimensional position-sensitive detector provided by an embodiment of the present application. As Figure 3 and Figure 4 shown, the two-dimensional position-sensitive detector 120 is successively divided into a P layer, an I layer, and an N layer from top to bottom. Among them, the corresponding output electrodes are respectively led out at the positions of the four center points on the upper surface of the P layer of the two-dimensional position-sensitive detector 120. Taking the Figure 3 shown coordinate system as an example, the output electrodes x1 and x2 are arranged oppositely in the horizontal x direction, and the output electrodes y1 and y2 are arranged oppositely in the y direction perpendicular to the horizontal x direction. The common electrode COM is led out from the N layer of the two-dimensional position-sensitive detector 120. In the present application, the upper and lower surfaces of the two-dimensional position-sensitive detector 120 are both square.

[0045] In the present application, the two-dimensional position-sensitive detector 120 is placed vertically. Therefore, the horizontal x direction of the two-dimensional position-sensitive detector 120 is consistent with the spatial horizontal X direction, and the corresponding y direction of the two-dimensional position-sensitive detector 120 is consistent with the spatial vertical Z direction.

[0046] As Figure 4 shown, after the light emitted by the light source becomes an annular Gaussian beam Light through the collimating lens, it is incident into the corresponding effective detection area of the two-dimensional position-sensitive detector 120, and an incident light spot is formed in the effective detection area. Due to the existence of the transverse electromotive force, charges proportional to the light intensity are generated at the positions corresponding to the incident light spot. These charges flow through the resistance layer on the surface of the P layer in the form of photocurrent, and the photocurrent is shunted according to the distance from the incident light spot to the output electrode. The photocurrent output by the output electrode is inversely proportional to the distance between the incident light spot position and each output electrode. In fact, by calculating the ratio of the output currents corresponding to each output electrode, the two-dimensional position information corresponding to the incident light spot can be accurately determined.

[0047] Specifically, when the center of the two-dimensional position-sensitive detector 120 is taken as the origin, there is:

[0048]

[0049] In formulas (1) to (4), I x1 represents the output current corresponding to the output electrode x1, I x2 represents the output current corresponding to the output electrode x2, I Ox represents the total photocurrent generated by the incident light spot in the horizontal x direction (I x1 +I x2 ), I Oy represents the total photocurrent generated by the incident light spot in the y direction (I y1 +I y2 ), L xRepresents the horizontal length of the effective area corresponding to the two-dimensional position-sensitive detector 120, L y Represents the vertical length of the effective area corresponding to the two-dimensional position-sensitive detector 120, X m Represents the horizontal distance from the center position of the two-dimensional position-sensitive detector 120 to the position of the incident light spot, Y m Represents the vertical distance from the center position of the two-dimensional position-sensitive detector 120 to the position of the incident light spot.

[0050] It can be known from formulas (1) to (4):

[0051]

[0052] The effective detection area corresponding to the two-dimensional position-sensitive detector 120 applied in this application adopts a square, that is, there is:

[0053] L x = L y (7)

[0054] The incident light beam in this application has an annular Gaussian distribution, and P-type resistance layers are adopted on the upper and lower surfaces of the two-dimensional position-sensitive detector 120 in this application. According to the PSD principle, the total photocurrent generated by the incident light spot in the horizontal x direction is equal to the total photocurrent generated by the incident light spot in the y direction, that is:

[0055] I Ox = I Oy (8)

[0056] Let I Ox = I Oy = I O , then there is:

[0057]

[0058] That is to say, it can be known from the above formulas (9) to (10) that when the total current I O generated by the incident light spot is determined, the distance X m , Y m between the position of the incident light spot and the center point of the two-dimensional position-sensitive detector 120 is linearly related and has nothing to do with the intensity of the incident light.

[0059] It can be known from the above formulas (8) to (9) that by obtaining I x2 - I x1 , I y2 - I y1 and I O , the distance X m , Y m between the incident light spot and the center point of the two-dimensional position-sensitive detector 120 can be obtained.

[0060] In this application, since the currents output by each output electrode of the PSD are not easily directly collected, and collecting the photocurrent signal requires costly devices, which will increase the cost of the entire system. For the convenience of subsequent calculation and processing and to reduce the system cost, it is necessary to convert I x2 -I x1 、I y2 -I y1 、I O into a voltage form that is easier to process, so as to complete the calculation and processing of the distance X m 、Y m between the incident light spot and the center point of the two-dimensional position-sensitive detector 120.

[0061] In a preferred embodiment, for the fine stage position detection device 1:

[0062] The two-dimensional position-sensitive detector 120 responds to the incident annular Gaussian beam, generates corresponding photocurrent signals at each output electrode and outputs them to the board unit 121. The board unit 121 performs voltage conversion processing on the photocurrent signals generated by each output electrode, obtains the voltage data corresponding to the fine stage position detection device 1 and sends it to the analog-to-digital conversion module 3. The analog-to-digital conversion module performs analog-to-digital conversion processing on the voltage data, obtains the target voltage data and inputs it to the position calculation module 2. The position calculation module 2 determines the position information of the fine stage relative to the coarse stage based on the target voltage data corresponding to each fine stage position detection device.

[0063] In a preferred embodiment, please refer to Figure 5 , Figure 5 shows a schematic structural diagram of a board unit provided by an embodiment of the present application. As Figure 5 shown, the board unit 121 includes a transimpedance amplification component 1210, a differential amplification component 1211 and a voltage summation component 1212. Among them, the output electrodes include two output cathodes x1 and x2 oppositely arranged in the horizontal direction x of the two-dimensional position-sensitive detector 120 and two output anodes y1 and y2 oppositely arranged in the vertical direction y. The voltage data includes the horizontal differential voltage corresponding to the two output cathodes x1 and x2, the vertical differential voltage corresponding to the two output anodes y1 and y2, and the target debiasing voltage. The target debiasing voltage is the debiased horizontal differential voltage output by the two output cathodes x1 and x2 or the debiased vertical differential voltage output by the two output anodes y1 and y2.

[0064] In a preferred embodiment, as Figure 5 shown, for each fine stage position detection device 1:

[0065] The transimpedance amplification component 1210 receives photocurrent signals from the respective output electrodes (including two output cathodes x1 and x2 and two output anodes y1 and y2) on the corresponding two-dimensional position-sensitive detector 120, and after processing, converts them into voltage processing signals corresponding to each output electrode and inputs them into the corresponding differential amplification component 1211. Specifically, the voltage processing signals include the voltage processing signal V x1a corresponding to the output cathode x1, the voltage processing signal V x2a corresponding to the output cathode x2, the voltage processing signal V y1a corresponding to the output anode y1, and the voltage processing signal V y2a .

[0066] The transimpedance amplification component 1210 inputs the voltage processing signals corresponding to the two output cathodes x1 and x2 or the voltage processing signals corresponding to the two output anodes y1 and y2 into the corresponding voltage summation component 1212. As shown in Figure 5 , only the case where the voltage processing signals corresponding to the two output cathodes x1 and x2 are input into the voltage summation component 1212 is shown.

[0067] Based on the voltage processing signals corresponding to each output electrode, the differential amplification component 1211 respectively outputs the horizontal differential voltages V xN and V xP corresponding to the two output cathodes, and the vertical differential voltages V yN and V yP corresponding to the two output anodes to the analog-to-digital conversion module 3.

[0068] Based on the voltage processing signals corresponding to the two output cathodes x1 and x2 or the voltage processing signals corresponding to the two output anodes y1 and y2, the voltage summation component 1212 outputs the target debiased voltages V Sum_pure_P and V sum_pure_N to the analog-to-digital conversion module 3.

[0069] After performing analog-to-digital conversion processing on the horizontal differential voltage, vertical differential voltage, and target debiased voltage, the analog-to-digital conversion module 3 outputs the horizontal processing voltage V xF , the vertical processing voltage V yF , and the debiased summation voltage V sum_pure to the position calculation module 2.

[0070] For each micro-stage position detection device, the position calculation module 2: Based on the horizontal processing voltage V xF , the vertical processing voltage V yF , and the debiased summation voltage V sum_pure , determines the two-dimensional position information X m and Y m of the incident light spot generated by the light source module on the two-dimensional position-sensitive detector relative to the macro-stage.

[0071] The position calculation module 2, based on the two-dimensional position information X m and Y m , after being solved by the position measurement and calculation matrix, obtains the position information of the micro stage relative to the coarse stage.

[0072] In a preferred embodiment, please refer to Figure 6 , Figure 6 which shows a schematic structural diagram of a transimpedance amplification component provided by an embodiment of the present application. As Figure 6 shown, the transimpedance amplification component 1210 includes a transimpedance amplification circuit corresponding to each output electrode. Specifically, it includes a first transimpedance amplification circuit 1210-A1 and 1210-A2 respectively connected to two output cathodes x1 and x2, and a second transimpedance amplification circuit 1210-B1 and 1210-B2 connected to two output anodes y1 and y2. The common-mode voltage includes a first common-mode voltage and a second common-mode voltage.

[0073] For the first transimpedance amplification circuit 1210-A1 corresponding to the output cathode x1, its first connection end is connected to the output cathode x1, its second connection end is connected to a given single power supply VCC, its third connection end is used as the output end of the first transimpedance amplification circuit 1210-A1 and is connected to the differential amplification component 1211, and its fourth connection end is connected to the first common-mode voltage V refh , and the output end of the first transimpedance amplification circuit 1210-A1 outputs the voltage processing signal V x1a corresponding to x1.

[0074] The connection method of the first transimpedance amplification circuit 1210-A2 corresponding to the output cathode x2 is similar to that of the first transimpedance amplification circuit 1210-A1 corresponding to the output cathode x1, and will not be elaborated here. The output end of the second transimpedance amplification circuit 1210-A2 is used to output the voltage processing signal V x2a corresponding to x2.

[0075] For the second transimpedance amplification circuit 1210-B1 corresponding to the output anode y1, its first connection end is connected to the output anode y1, its second connection end is grounded, its third connection end is used as the output end of the second transimpedance amplification circuit 1210-B1 and is connected to the differential amplification component 1211, and its fourth connection end is connected to the second common-mode voltage V refl , and the output end of the second transimpedance amplification circuit 1210-B1 is used to output the voltage processing signal V y1a corresponding to y1.

[0076] The connection method of the second transimpedance amplifier circuit 1210-B2 corresponding to the output anode y2 is similar to that of the second transimpedance amplifier circuit 1210-B1 corresponding to the output anode y1, and will not be elaborated here. The output end of the second transimpedance amplifier circuit 1210-B2 is used to output the voltage processing signal V corresponding to y2 y2a 。

[0077] In a preferred embodiment, the transimpedance amplifier circuit includes a current-to-voltage structure and a bias current compensation structure. Among them, for the transimpedance amplifier circuit: if the transimpedance amplifier circuit is connected to the output cathode, one end of the bias current compensation structure is connected to a given single power supply; if the transimpedance amplifier circuit is connected to the output anode, one end of the bias current compensation structure is grounded

[0078] The other end of the bias current compensation structure is respectively connected to the inverting input end of the current-to-voltage structure and the output electrode corresponding to the two-dimensional position sensitive detector 120. The non-inverting input end of the current-to-voltage structure is connected to the corresponding common-mode voltage output end, and the output end of the current-to-voltage structure is connected to the differential amplification component as the output end of the transimpedance amplifier circuit

[0079] Preferably, if the transimpedance amplifier circuit is connected to the output cathode, the non-inverting input end of the current-to-voltage structure corresponding to the transimpedance amplifier circuit is connected to the first common-mode voltage V refh ; if the transimpedance amplifier circuit is connected to the output anode, the non-inverting input end of the current-to-voltage structure corresponding to the transimpedance amplifier circuit is connected to the second common-mode voltage V refl 。

[0080] Please refer to Figure 7 , Figure 7 which shows a schematic structural diagram of a transimpedance amplifier circuit provided by an embodiment of the present application. As Figure 7 shown, the current-to-voltage structure includes a first operational amplifier U1, a first resistor R1, a first capacitor C1, a second capacitor C2, and a second resistor R2. The bias current compensation structure includes a third resistor R3. The first resistor R1 is the feedback resistor of the first operational amplifier U1. The first operational amplifier U1 is a transimpedance amplifier, and the third resistor R3 is a bias resistor for generating a bias current

[0081] For the first transimpedance amplifier circuit, one end of the third resistor R3 is connected to the given single power supply VCC, and the other end of the third resistor R3 is respectively connected to one end of the first capacitor C1, one end of the first resistor R1, the inverting input end of the first operational amplifier U1, and the output cathode corresponding to the first transimpedance amplifier circuit. The other end of the first capacitor C1 is connected to the other end of the first resistor R1 and then connected to the output end of the first operational amplifier U1. The positive power input end of the first operational amplifier U1 is connected to the given single power supply VCC through the second resistor R2. The negative power input end of the first operational amplifier U1 is grounded to GND. The non-inverting input end of the first operational amplifier U1 is connected to the first common-mode voltage V corresponding to the output electroderefh 。

[0082] For the second transimpedance amplifier circuit, one end of the third resistor R3 is grounded to GND, and the other end of the third resistor R3 is respectively connected to one end of the first capacitor C1, one end of the first resistor R1, the inverting input terminal of the first operational amplifier U1, and the output anode corresponding to the second transimpedance amplifier circuit. The other end of the first capacitor C1 is connected to the other end of the first resistor R1 and then connected to the output terminal of the first operational amplifier U1. The positive power supply input terminal of the first operational amplifier U1 is connected to the given single power supply VCC through the second resistor R2, the negative power supply input terminal of the first operational amplifier U1 is grounded, and the non-inverting input terminal of the first operational amplifier U1 is connected to the second common-mode voltage V refl 。

[0083] In this application, the two-dimensional position-sensitive detector 120 requires at least a 5V bias voltage during operation. To meet the normal operating requirements of the two-dimensional position-sensitive detector 120 and reduce the impact on the temperature of the workbench, the transimpedance amplifier circuit in this application is powered by the given single power supply VCC. The given single power supply VCC can be selected as 8V. Powering with the given single power supply VCC not only reduces the overall power consumption of the two-dimensional position-sensitive detector 120, but also simplifies the circuit design, further reducing the volume of the device.

[0084] However, powering with the given single power supply VCC has a certain impact on the signal processing margin of the circuit. To prevent the output of the first operational amplifier U1 from reaching the limit of the given single power supply VCC, a bias current is added to the inverting input terminal of the first operational amplifier U1 by introducing the third resistor R3.

[0085] In a specific embodiment, assuming that the resistance value of the first resistor R1 is 37.5 kΩ (kiloohm), the resistance value of the third resistor R3 is 7.5 kΩ, the resistance value of the second resistor R2 is 10R, and the given single power supply VCC = 8V, taking one of the first transimpedance amplifier circuits connected to the output cathode x1 as an example:

[0086] Assume that the output voltage V corresponding to the first common-mode voltage output terminal refh = 6.5V. Then, the voltage drop across the third resistor R3 at this time = 8V - 6.5V = 1.5V. Finally, the bias current at the inverting input terminal corresponding to the first operational amplifier U1 is approximately 200 μA (microampere). At this time, when there is no photocurrent output at the output cathode x1, the voltage processing signal V x1a output by this first transimpedance amplifier circuit is:

[0087] V x1a (I x1 = 0A) = 6.5V - (200 μA × R1) = 0.5V (11)

[0088] Similarly, based on another first transimpedance amplifier circuit connected to the output cathode x2, the voltage processing signal V corresponding to the output cathode x2 output by the transimpedance amplifier component can be obtained as follows: x2a is:

[0089] V x2a (I x2 = 0 A) = V x1a (I x1 = 0 A) = 0.5 V(12)

[0090] At this time, the output of the transimpedance amplifier in the first transimpedance amplifier circuit is avoided from being affected by the power supply voltage clipping. The voltage processing signals V corresponding to the two output cathodes x1 and x2 x1a and V x2a are input to the differential amplifier component.

[0091] Taking one of the second transimpedance amplifier circuits connected to the output anode y1 as an example:

[0092] Since the first operational amplifier U1 connected to the output anode needs to absorb the photocurrent, as the photocurrent increases, the output voltage decreases. Therefore, assuming that the output voltage V corresponding to the second common-mode voltage output terminal refl = 1.5 V, the voltage drop across the third resistor R3 at this time is 1.5 V, and the bias current is about 200 μA. At this time, when there is no photocurrent output from the output anode y1, the voltage processing signal V output by this second transimpedance amplifier circuit y1a is:

[0093] V y1a (I y1 = 0 A) = 1.5 V + (200 μA × R1) = 7.5 V(13)

[0094] The second transimpedance amplifier circuits corresponding to the two output anodes are designed identically. Therefore, the voltage processing signal V corresponding to the output cathode y2 is obtained as follows: y2a is:

[0095] V y2a (I y2 = 0 A) = V y1a (I y1 = 0 A) = 7.5 V(14)

[0096] Through the above transimpedance amplifier circuit design, the outputs of the transimpedance amplifiers in the transimpedance amplifier circuit all have sufficient margins, significantly optimizing the dynamic range of the transimpedance amplifier and improving the linearity and signal-to-noise ratio.

[0097] In a preferred embodiment, the first common-mode voltage V refh and the second common-mode voltage V refl in this application are provided by a common-mode voltage generation circuit.

[0098] The board unit 121 further includes a common-mode voltage generation circuit 1213, and the common-mode voltage generation circuit includes a first common-mode voltage division structure, a second common-mode voltage division structure, a third common-mode voltage division structure, a fourth common-mode voltage division structure, and a fifth common-mode voltage division structure.

[0099] Specifically, one end of the first common-mode voltage division structure is connected to one end of the second common-mode voltage division structure and serves as the first common-mode power supply output terminal. The other end of the second common-mode voltage division structure is respectively connected to one end of the third common-mode voltage division structure and the ground. The other end of the third common-mode voltage division structure is connected to one end of the fourth common-mode voltage division structure and serves as the second common-mode power supply output terminal. The other end of the fourth common-mode voltage division structure is connected to one end of the fifth common-mode voltage division structure and serves as the third common-mode power supply output terminal. The other end of the fifth common-mode voltage division structure is connected to the other end of the first common-mode voltage division structure and then connected to a given single power supply.

[0100] In a specific embodiment, please refer to Figure 8 , Figure 8 which shows a schematic structural diagram of a common-mode voltage generation circuit provided by an embodiment of the present application. As Figure 8 shown, the first common-mode voltage division structure selects the first common-mode voltage division resistor Rh1, the second common-mode voltage division structure selects the second common-mode voltage division resistor Rh2, the third common-mode voltage division structure selects the third common-mode voltage division resistor Rh3, the fourth common-mode voltage division structure selects the first common-mode voltage division resistor Rh4, the fifth common-mode voltage division structure selects the first common-mode voltage division resistor Rh5, and the common-mode voltage generation circuit further includes a third capacitor C3 and a fourth capacitor C4.

[0101] Specifically, one end of the first common-mode voltage division resistor Rh1 is connected to one end of the second common-mode voltage division resistor Rh2 and serves as the first common-mode power supply output terminal to output the first common-mode voltage V refh , the other end of the second common-mode voltage division resistor Rh2 is respectively connected to one end of the third common-mode voltage division resistor Rh3 and the ground GND. The other end of the third common-mode voltage division resistor Rh3 is connected to one end of the fourth common-mode voltage division resistor Rh4 and serves as the second common-mode power supply output terminal to output the first common-mode voltage V refl , the other end of the fourth common-mode voltage division resistor Rh4 is connected to one end of the fifth common-mode voltage division resistor Rh5 and serves as the third common-mode power supply output terminal to output the third common-mode voltage V refm , and the other end of the fifth common-mode voltage division resistor Rh5 is connected to the other end of the first common-mode voltage division resistor Rh1 and then connected to a given single power supply VCC.

[0102] One end of the third capacitor C3 is connected to one end of the fifth common-mode voltage division resistor Rh5, the other end of the third capacitor C3 is grounded GND, one end of the fourth capacitor C4 is connected to one end of the fourth common-mode voltage division resistor Rh4, and the other end of the fourth capacitor C4 is grounded GND.

[0103] In a specific embodiment, as Figure 8 shown, the first common-mode voltage V refh is divided by the first common-mode voltage-dividing resistor Rh1 and the second common-mode voltage-dividing resistor Rh2. Specifically:

[0104]

[0105] Among them, the first common-mode voltage-dividing resistor Rh1 can be selected as 10 kΩ, and the second common-mode voltage-dividing resistor Rh2 can be selected as 44.4 kΩ.

[0106] The second common-mode voltage V refl is divided by the third common-mode voltage-dividing resistor Rh3, the fourth common-mode voltage-dividing resistor Rh4, and the fifth common-mode voltage-dividing resistor Rh5. Specifically:

[0107]

[0108] The third common-mode voltage-dividing resistor Rh3 can be selected as 14.7 kΩ, and the fourth common-mode voltage-dividing resistor Rh4 can be selected as 10 kΩ.

[0109] The third common-mode voltage V refm is divided by the third common-mode voltage-dividing resistor Rh3, the fourth common-mode voltage-dividing resistor Rh4, and the fifth common-mode voltage-dividing resistor Rh5. Specifically:

[0110]

[0111] The fifth common-mode voltage-dividing resistor Rh5 can be selected as 53.6 kΩ.

[0112] The devices selected for the two transimpedance amplifier circuits connected to the output cathode are the same, and the devices selected for the two transimpedance amplifier circuits connected to the output anode are the same. In a special embodiment of the present application, the component specifications selected for all the transimpedance amplifier circuits connected to different output electrodes are exactly the same. Therefore, from Figure 7 it can be known that:

[0113]

[0114] It can be known from Equation (18) to Equation (19) that after passing through the transimpedance amplification component, the voltage difference V Δx between the cathode output terminals x1 and x2 is:

[0115] V Δx = V x1a - V x2a = (I x1 - I x2 ) × R1(22)

[0116] According to Equation (8), Equation (15), Equation (18), and Equation (19), there is:

[0117]

[0118] In formula (23), V sum represents the sum voltage between the voltage processing signal V x1a output by the transimpedance amplifier circuit corresponding to the output cathode x1 and the voltage processing signal V x2a output by the transimpedance amplifier circuit corresponding to the output cathode x2.

[0119] As can be seen from formulas (20) to (21), after passing through the transimpedance amplification component, the voltage difference V Δy between the anode output terminals y1 and y2 is:

[0120] V Δy = V y1a - V y2a = (I y1 - I y2 ) × R1 (24)

[0121] As can be seen from formulas (22) and (24), the output voltage difference corresponding to the horizontal output electrodes x1 and x2 has nothing to do with the first common-mode voltage V refh , and is only related to the photocurrent difference (I x1 - I x2 ) between the horizontal output electrodes x1 and x2 and the feedback resistor R1. Similarly, the output voltage difference corresponding to the vertical output electrodes y1 and y2 has nothing to do with the second common-mode voltage V refl , and is only related to the photocurrent difference (I y1 - I y2 ) between the vertical output electrodes y1 and y2 and the feedback resistor R1. Therefore, the setting of the bias voltage in the transimpedance amplifier circuit does not affect the position detection of the incident light spot.

[0122] In this application, for the voltage subtraction corresponding to formulas (22) and (24), as Figure 5 shown, it is implemented by the differential amplification component 1211. To further improve the anti-interference ability and ensure high signal fidelity in the single-power-supply scheme, the "virtual ground" is removed, and the differential amplification component 1211 is used to convert the voltage processing signal output by the transimpedance amplification component into a "differential signal" respectively.

[0123] In a preferred embodiment, please refer to Figure 9 , Figure 9 which shows a schematic structural diagram of a differential amplification component provided by an embodiment of the present application. As Figure 9 shown, the differential amplification component includes a cathode differential amplification circuit 1211-A and an anode differential amplification circuit 1211-B.

[0124] Among them, the first input terminal of the anode differential amplifier circuit 1211-B is connected to the output terminal of the transimpedance amplifier circuit corresponding to one of the output anodes y1 of the two-dimensional position sensitive detector, that is, the voltage processing signal V corresponding to one of the output anodes y1 is accessed. y1a The second input terminal of the anode differential amplifier circuit 1211-B is connected to the output terminal of the transimpedance amplifier circuit corresponding to the other input anode y2 of the two-dimensional position sensitive detector, that is, the voltage processing signal V corresponding to the other output anode y2 is accessed. y2a The common-mode voltage input terminal of the anode differential amplifier circuit is connected to the third common-mode voltage output terminal. The positive differential output terminal and the negative differential output terminal of the anode differential amplifier circuit 1211-B are respectively connected to the analog-to-digital conversion module 3. The positive differential output terminal of the anode differential amplifier circuit 1211-B outputs the vertical differential voltage V yP The negative differential output terminal of the anode differential amplifier circuit 1211-B outputs the vertical differential voltage V yN .

[0125] The first input terminal of the cathode differential amplifier circuit 1211-A is connected to the output terminal of the transimpedance amplifier circuit corresponding to one of the output cathodes x1 of the two-dimensional position sensitive detector, that is, the voltage processing signal V corresponding to one of the output cathodes x1 is accessed. x1a The second input terminal of the cathode differential amplifier circuit 1211-A is connected to the output terminal of the transimpedance amplifier circuit corresponding to the other input cathode y2 of the two-dimensional position sensitive detector, that is, the voltage processing signal V corresponding to the other output cathode x2 is accessed. x2a The common-mode voltage input terminal of the cathode differential amplifier circuit is connected to the third common-mode voltage output terminal. The positive differential output terminal and the negative differential output terminal of the cathode differential amplifier circuit 1211-A are respectively connected to the analog-to-digital conversion module 3. The positive differential output terminal of the cathode differential amplifier circuit 1211-A outputs the horizontal differential voltage V xP The negative differential output terminal of the cathode differential amplifier circuit 1211-A outputs the horizontal differential voltage V xN .

[0126] In a preferred embodiment, please refer to Figure 10 , Figure 10 which shows a schematic structural diagram of a differential amplifier circuit provided by an embodiment of the present application. As Figure 10 shown, the differential amplifier circuit includes a first voltage-dividing resistor Rg1, a second voltage-dividing resistor Rg2, a third voltage-dividing resistor Rg3, a fourth voltage-dividing resistor Rg4 and a differential amplification structure UW. The first voltage-dividing resistor Rg1 and the third voltage-dividing resistor Rg3 have the same specifications, and the second voltage-dividing resistor Rg2 and the fourth voltage-dividing resistor Rg4 have the same specifications.

[0127] Preferably, one end of the first voltage-dividing resistor Rg1 serves as the first input terminal of the differential amplification circuit, the other end of the first voltage-dividing resistor Rg1 is connected to one end of the second voltage-dividing resistor Rg2 and the inverting input terminal of the differential amplification structure UW, and the other end of the second voltage-dividing resistor Rg2 is connected to one of the output terminals of the differential amplification structure UW and serves as the positive differential output terminal of the differential amplification circuit.

[0128] One end of the third voltage-dividing resistor Rg3 serves as the second input terminal of the differential amplification circuit, the other end of the third voltage-dividing resistor Rg3 is connected to one end of the fourth voltage-dividing resistor Rg4 and the non-inverting input terminal of the differential amplification structure UW, and the other end of the fourth voltage-dividing resistor Rg4 is connected to the other output terminal of the differential amplification structure UW and serves as the negative differential output terminal of the differential amplification circuit.

[0129] The common-mode voltage input terminal of the differential amplification structure UW is connected to the third common-mode voltage V refm .

[0130] In a specific embodiment, as Figure 10 shown, the differential amplification component structure UW includes a fourth resistor R4, a fifth capacitor C5, and a second operational amplifier U2. Among them, the fourth resistor R4 can be selected as 10R. The inverting input terminal of the second operational amplifier U2 is connected to the other end of the first voltage-dividing resistor Rg1, the non-inverting input terminal of the second operational amplifier U2 is connected to the other end of the third voltage-dividing resistor Rg3, and the common-mode voltage input terminal of the second operational amplifier U2 is connected to the third common-mode voltage V refm . The positive power supply input terminal of the second operational amplifier U2 is respectively connected to one end of the fifth capacitor C5 and one end of the fourth resistor R4. The other end of the fourth resistor R4 is connected to the given single power supply VCC. The other end of the fifth capacitor C5 is grounded. The negative power supply input terminal of the second operational amplifier U2 is grounded to GND. The positive differential voltage output terminal and the negative differential voltage output terminal of the second operational amplifier U2 are connected to the analog-to-digital conversion module 3.

[0131] Specifically, when the differential amplification circuit is a cathode differential amplification circuit, one end of the third voltage-dividing resistor Rg3 is connected to the input cathode x1, one end of the first voltage-dividing resistor Rg1 is connected to the input cathode x2, and the positive differential voltage output terminal of the second operational amplifier U2 outputs the horizontal differential voltage V xP to the analog-to-digital conversion module 3, and the negative differential voltage output terminal of the second operational amplifier U2 outputs the horizontal differential voltage V xN to the analog-to-digital conversion module 3.

[0132] When the differential amplification circuit is an anode differential amplification circuit, one end of the third voltage-dividing resistor Rg3 is connected to the input anode y1, one end of the first voltage-dividing resistor Rg1 is connected to the input anode y2, and the positive differential voltage output terminal of the second operational amplifier U2 outputs the vertical differential voltage V yPTo the analog-to-digital conversion module 3, the vertical differential voltage V is output from the negative differential voltage output terminal of the second operational amplifier U2 yN To the analog-to-digital conversion module 3.

[0133] From Figure 10 It can be seen that for the cathode differential amplifier circuit:

[0134]

[0135] According to formula (25) and formula (26), there is:

[0136]

[0137] Among them, let Rg1 = Rg3 = Ra, Rg2 = Rg4 = Rb, then there is:

[0138]

[0139] Similarly, for the anode differential amplifier circuit, we get:

[0140]

[0141] From formula (23), it can be seen that the total voltage V sum contains the unwanted bias signal V err :

[0142]

[0143] The bias signal V err needs to be subtracted from the total voltage V sum This function is realized by the voltage summing component 1212. In a preferred embodiment, please refer to Figure 11 , Figure 11 shows a schematic structural diagram of a voltage summing component provided by an embodiment of the present application. As Figure 11 shown, the voltage summing component 1212 includes a non-inverting summing structure 1212-A, an inverting feedback structure 1212-B, and a differential processing structure 1212-C. The feedback generated by the non-inverting summing structure 1212-A is equal to the feedback generated by the inverting feedback structure 1212-B.

[0144] Preferably, the first connection end and the second connection end of the in-phase summing structure 1212-A are respectively connected to the output ends of the transimpedance amplifier circuits corresponding to two output cathodes x1 and x2 or the output ends of the transimpedance amplifier circuits corresponding to two output anodes y1 and y2 (taking the connection to the output ends of the transimpedance amplifier circuits corresponding to the output cathodes x1 and x2 as an example in the figure). The output end of the in-phase summing structure 1212-A is connected to the in-phase input end of the differential processing structure 1212-C. The first connection end of the inverting feedback structure 1212-B is connected to a given single power supply VCC, the second connection end of the inverting feedback structure 1212-B is grounded to GND, the output end of the inverting feedback structure 1212-B is connected to the inverting input end of the differential processing structure 1212-C. The positive differential output end and the negative differential output end of the differential processing structure 1212-C are connected to the position calculation module 2, and the positive differential output end and the negative differential output end of the differential processing structure 1212-C respectively output the debiased horizontal differential voltage output by two output cathodes or the debiased vertical differential voltage output by two output anodes.

[0145] Figure 11 Taking the voltage summing component as an example of being connected to the output ends of the transimpedance amplifier circuits corresponding to two output cathodes x1 and x2, the positive differential output end of the differential processing structure 1212-C outputs the debiased horizontal differential voltage V sum_pure_P and the negative differential output end of the differential processing structure 1212-C outputs the debiased horizontal differential voltage V sum_pure_N .

[0146] In a preferred embodiment, the in-phase summing structure 1212-A includes a first summing voltage-dividing resistor RF1 and a second summing voltage-dividing resistor RF2. The inverting feedback structure 1212-B includes a third summing voltage-dividing resistor RF3, a fourth summing voltage-dividing resistor RF4, a fifth summing voltage-dividing resistor RF5, and a sixth summing voltage-dividing resistor RF6. The differential processing structure 1212-C includes a third operational amplifier U3, a fifth resistor R5, and a sixth resistor R6.

[0147] In a specific embodiment, if the summing voltage-dividing component is connected to the voltage processing signals corresponding to two output cathodes, one end of the first summing voltage-dividing resistor RF1 is connected to V x1a and one end of the second summing voltage-dividing resistor RF2 is connected to V x2a .

[0148] If the summing voltage-dividing component is connected to the voltage processing signals corresponding to two output anodes, one end of the first summing voltage-dividing resistor RF1 is connected to V y1a and one end of the second summing voltage-dividing resistor RF2 is connected to V y2a .

[0149] The other end of the first summing voltage-dividing resistor RF1 is connected to the other end of the second summing voltage-dividing resistor RF2, and then they are respectively connected to the non-inverting input terminal of the third operational amplifier U3 and one end of the sixth resistor R6. The other end of the sixth resistor R6 is connected to the negative differential output terminal V of the third operational amplifier U3 sum_pure_N 。

[0150] One end of the third summing voltage-dividing resistor RF3 and one end of the fourth summing voltage-dividing resistor RF4 are connected and then connected to the given single voltage source VCC. One end of the fifth summing voltage-dividing resistor RF5 and one end of the sixth summing voltage-dividing resistor RF6 are connected and then grounded. After the other end of the third summing voltage-dividing resistor RF3 and the other end of the fourth summing voltage-dividing resistor RF4 are connected, they are connected to the other end of the fifth summing voltage-dividing resistor RF5 and one end of the fifth resistor R5. The other end of the sixth summing voltage-dividing resistor RF6 is connected to the inverting input terminal of the third operational amplifier U3, and the common-mode input terminal of the third operational amplifier U3 is connected to the third common-mode output terminal v refm 。

[0151] The other end of the fifth resistor R5 is connected to the positive differential output terminal V of the third operational amplifier U3 sum_pure_P 。

[0152] As can be seen from formula (27), in the voltage summing component, to eliminate the influence of the third common-mode voltage V refm , the feedback of the non-inverting input terminal and the inverting input terminal must be equal, that is:

[0153]

[0154] To subtract the bias signal V err , it is necessary to make the gain from the given single voltage VCC to the output opposite to the gain from V xP , V xN to the output. According to formula (15) and formula (28), we can get:

[0155]

[0156] The voltage sum value after removing the bias signal:

[0157]

[0158] The position calculation module can be a host computer or a processor.

[0159] In a preferred embodiment, the position calculation module determines the two-dimensional position information of the incident light spot corresponding to each micro-stage position detection device through the following formula:

[0160]

[0161] In this formula, X mRepresents the horizontal position of the incident light spot generated on the two-dimensional position-sensitive detector relative to the center point of the two-dimensional position-sensitive detector, Y m Represents the vertical position of the incident light spot generated on the two-dimensional position-sensitive detector relative to the center point of the two-dimensional position-sensitive detector, V sum_pure Represents the debiased summing voltage output by the analog-to-digital conversion module, V xF Represents the horizontal processing voltage output by the analog-to-digital conversion module, V yF Represents the vertical processing voltage output by the analog-to-digital conversion module.

[0162] V xP Represents the horizontal differential voltage output by the positive differential output terminal of the cathode differential amplifier circuit, V xN Represents the horizontal differential voltage output by the negative differential output terminal of the cathode differential amplifier circuit, V yP Represents the vertical differential voltage output by the positive differential output terminal of the anode differential amplifier circuit, V yN Represents the vertical differential voltage output by the negative differential output terminal of the anode differential amplifier circuit, V sum_pure_p Represents the voltage output by the positive differential output terminal of the voltage summing component, V sum_pure_N Represents the voltage output by the negative differential output terminal of the voltage summing component, V xF 、V yF and V sum_pure Output by the analog-to-digital conversion module.

[0163] In a preferred embodiment, please refer to Figure 12 , Figure 12 shows a schematic diagram of a light source driving connection structure provided by an embodiment of the present application. As Figure 12 shown, the board unit 121 further includes a photoelectric current servo circuit 1214 and a light source driving circuit. The light source driving circuit includes a feedback circuit 110, a current regulation circuit 111, a light source voltage regulation circuit 112, and a light source 113.

[0164] Among them, the inverting input terminal of the light source current servo circuit 1214 is connected to any differential output terminal of the voltage summing component (the positive differential output terminal or the negative differential output terminal of the voltage summing component), the non-inverting input terminal of the light source current servo circuit 1214 is connected to the cathode of the light source 113, the output terminal of the light source current servo circuit 1214 is connected to the input terminal of the feedback circuit 110, the output terminal of the feedback circuit 110 is respectively connected to the adjustment signal feedback terminal of the current regulation circuit 111 and the cathode of the light source 113, the power supply terminal of the current regulation circuit 111 is connected to the given single power supply VCC, the output terminal of the current regulation circuit 111 is connected to the anode of the light source 113, and the light source voltage regulation circuit 112 is connected in parallel between the anode and the cathode of the light source component.

[0165] In a specific embodiment, the light source current servo circuit 1214 includes a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a sixth capacitor C6, a seventh capacitor C7, and a fourth operational amplifier U4.

[0166] The feedback circuit 110 includes a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, and a control switch Q1.

[0167] The current regulation circuit 111 includes a current-mode DC-DC buck module U5, a seventeenth resistor R17, an eighteenth resistor R18, an eighth capacitor C8, a ninth capacitor C9, a first diode D1, a first inductor L1, a tenth capacitor C10, and an eleventh capacitor C11.

[0168] The light source voltage regulation circuit 112 includes a nineteenth resistor R19, a twentieth resistor R20, and a voltage regulation chip U6.

[0169] Among them, one end of the seventh resistor R7 is connected to any differential output terminal of the voltage summing component (the positive differential output terminal V sum_pure_p or the negative differential output terminal V sum_pure_N) The other end of the seventh resistor R7 is respectively grounded to GND through the eighth resistor R8 and connected to the inverting input terminal of the fourth operational amplifier U4 through the ninth resistor R9. The inverting input terminal of the fourth operational amplifier U4 is also connected to the output terminal of the fourth operational amplifier U4 through the sixth capacitor C6. The non-inverting input terminal of the fourth operational amplifier U4 is connected to the given single power supply VCC through the tenth resistor R10. The non-inverting input terminal of the fourth operational amplifier U4 is also connected to the cathode of the light source 113 through the eleventh resistor R11. The non-inverting input terminal of the fourth operational amplifier U4 is also respectively grounded to GND through the twelfth resistor R12, grounded through the thirteenth resistor R13, and connected to the seventh capacitor C7. The output terminal of the fourth operational amplifier U4 is connected to one end of the fourteenth resistor R14. The other end of the fourteenth resistor R14 is respectively grounded through the fifteenth resistor R15 and connected to the gate of the control switch Q1. The source of the control switch Q1 is grounded through the sixteenth resistor R16. The drain of the control switch Q1 is connected to the voltage feedback pin of the current-mode DC-DC buck module U5. The power input terminal of the DC-DC buck module U5 is connected to the given single power supply VCC. The eighth capacitor C8 is connected in series between the given single power supply VCC and GND. The current detection pin of the current-mode DC-DC buck module U5 is connected to the given single power supply VCC through the seventeenth resistor R17. The current limiting pin of the current-mode DC-DC buck module U5 is grounded through the eighteenth resistor R18 and the ninth capacitor C9 in sequence. The grounding pin of the current-mode DC-DC buck module U5 is grounded. The current output control terminal of the current-mode DC-DC buck module U5 is connected to the cathode of the first diode D1 and one end of the first inductor L1. The other end of the first inductor L1 is respectively connected to one end of the tenth capacitor C10, one end of the eleventh capacitor C11, one end of the nineteenth resistor R19, the cathode end of the voltage regulator chip U6, and the anode of the light source 113. The other end of the tenth capacitor C10, the other end of the eleventh capacitor C11, and the anode of the first diode D1 are connected and then grounded to GND. The control terminal of the voltage regulator chip U6 is respectively connected to the other end of the nineteenth resistor R19 and one end of the twentieth resistor R20. The other end of the twentieth resistor R20 is connected to the anode end of the voltage regulator chip U6 and then connected to the feedback pin of the current-mode DC-DC buck module U5 and the cathode of the light source 113.

[0170] In this application, in order to achieve low-power design and extend the service life of the light source 113, the current servo loop control circuit 1214 as shown in Figure 12 is designed. The current servo loop control circuit 1214 will keep the photocurrent generated by the lateral photoelectric effect of the two-dimensional position sensitive detector constant. For example, the photocurrent generated by the lateral photoelectric effect of the two-dimensional position sensitive detector is controlled to be constant at 160 μA, corresponding to the current of the light source 113 being constant at 5 mA.

[0171] Since the semiconductor lifetime is significantly affected by temperature, after the light source 113 has been used for a certain period of time, the light source 113 and the two-dimensional position sensitive detector begin to degrade. At this time, the current servo loop control circuit 1214 will appropriately increase the current of the light source 113 to keep the photocurrent of the two-dimensional position sensitive detector constant. The maximum current of the light source 113 restricted by the current servo loop control circuit 1214 is 15 mA. When this current limit is reached, the photocurrent will be lower than 160 μA, indicating that the light source 113 or the two-dimensional position sensitive detector has reached the end of its service life, but the overall system can still operate at this time.

[0172] In a preferred embodiment, the position calculation module determines the position information of the micro-stage relative to the macro-stage in the following manner:

[0173] Obtain the spatial position information of the light source in each micro-stage position detection device in the spatial coordinate system with the center of the micro-stage as the origin coordinate. Based on the spatial position information corresponding to each micro-stage position detection device, establish a position measurement solution matrix. The position measurement solution matrix describes the solution relationship between the two-dimensional position information corresponding to multiple micro-stage position detection devices and the six-degree-of-freedom position information of the micro-stage relative to the macro-stage. According to the position measurement solution matrix and the two-dimensional position information corresponding to each micro-stage position detection device, determine the six-degree-of-freedom position information of the micro-stage relative to the macro-stage.

[0174] In a specific embodiment, the micro-stage position measurement system provided by the present application includes 3 micro-stage position detection devices, and the light sources in the 3 micro-stage position detection devices are respectively arranged in the three orientations as shown in Figure 1 Specifically, they are respectively arranged on the 360-degree trisectors starting from the center of the micro-stage, and the spatial position information of the 3 light sources relative to the center of the micro-stage in space is given in advance. Specifically, as shown in Table 1 below, Table 1 is the light source position information table.

[0175] Table 1

[0176] Light source x′(mm) y′(mm) z′(mm) LED1 0 65 -26 LED2 -56.3 -32.5 -26 LED3 56.3 -32.5 -26

[0177] As shown in Table 1, combined with Figure 1 , the spatial position information corresponding to the light source LED1 is (x1′, y1′, z1′) = (0, 65, -26), the spatial position information corresponding to the light source LED2 is (x2′, y2′, z2′) = (-56.3, -32.5, -26), and the spatial position information corresponding to the light source LED3 is (x3′, y3′, z3′) = (56.3, -32.5, -26).

[0178] In this embodiment, the two-dimensional position information calculated by the micro-stage position detection device corresponding to the light source LED1 is X m1 、Y m1, the two-dimensional position information calculated by the micro-stage position detection device corresponding to the light source LED2 is X m2 , Y m2 , the two-dimensional position information calculated by the micro-stage position detection device corresponding to the light source LED3 is X m3 , Y m3 .

[0179] There exists [X m1 X m2 X m3 Y m1 Y m2 Y m3 T = Q × [X f Y f R z Z f R x R y T (34)

[0180] Among them, Q represents the position measurement and calculation matrix, which is determined according to the spatial position information of the three light sources. X f represents the horizontal X-direction position of the micro-stage relative to the coarse-stage, Y f represents the horizontal Y-direction position of the micro-stage relative to the coarse-stage, Z f represents the vertical position in space of the micro-stage relative to the coarse-stage, R x represents the horizontal X-direction rotation of the micro-stage relative to the coarse-stage, R y represents the horizontal Y-direction rotation of the micro-stage relative to the coarse-stage, R z represents the spatial vertical rotation of the micro-stage relative to the coarse-stage.

[0181] Among them,

[0182]

[0183] Substitute the two-dimensional position information of the 3 light sources and Q into formula (34) for calculation, and the six-degree-of-freedom position information of the micro-stage relative to the coarse-stage (X f Y f R z Z f R x R y ) can be obtained.

[0184] The beneficial effect of this application is that:

[0185] ​​1. The microstage position measurement system provided by this application uses a two-dimensional position-sensitive detector to detect the position of the incident light, thereby realizing the calculation of the microstage position. Since the two-dimensional position-sensitive detector is a non-segmented optical sensor that utilizes the surface resistance of a photodiode and can provide a continuous electrical signal, this application has the advantages of high resolution, fast response speed, and high reliability in the process of detecting the microstage position.

[0186] 2. The microstage position measurement system provided by this application has the advantages of high signal-to-noise ratio and strong anti-interference ability. Physical measures such as optical collimating lenses and light shields are used to minimize the errors introduced by ambient light. Circuit designs such as bias current compensation design, bias voltage, difference calculation, and summation significantly improve the dynamic range and signal-to-noise ratio of the sensing device. Finally, the normalization calculation method is used to eliminate the influence of high-frequency jitter and light intensity change of the light source.

[0187] 3. Low power consumption and long service life: Since the workpiece stage is extremely sensitive to temperature, the present invention adopts a single power supply and low-power-consuming devices to achieve low-power design and minimize the influence on the workpiece stage as much as possible.

[0188] 4. The current servo loop control circuit designed in this application ensures that the light source operates at a low current, effectively increasing the service life of the two-dimensional position-sensitive detector. As the usage time increases, the two-dimensional position-sensitive detector or the light source degrades. At this time, the current servo loop control circuit can correspondingly increase the light source current to keep the photocurrent of the two-dimensional position-sensitive detector constant.

[0189] 5. This application can integrate the light source module and the position measurement module into one unit, with a compact structure and small occupied space, making it suitable for application in a workpiece stage with limited size and space.

[0190] Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the above-described systems and devices can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated here. In the several embodiments provided by this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there can be other division methods in actual implementation. For another example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some communication interfaces, and the indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0191] The unit described as a separation component may or may not be physically separated. The component displayed as a unit may or may not be a physical unit, that is, it may be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0192] In addition, each functional unit in various embodiments of the present application may be integrated in a processing unit, may exist separately as individual physical units, or two or more units may be integrated in one unit.

[0193] If the above functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium executable by a processor. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present application. The foregoing storage medium includes: USB flash drives, mobile hard disks, read-only memories (ROM), random access memories (RAM), magnetic disks, or optical discs, and other various media that can store program codes.

[0194] The above are only the specific implementation manners of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present application, and all should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A micro-motion stage position measurement system, characterized in that: The micro-motion stage position measurement system includes a plurality of micro-motion stage position detection devices and a position calculation module. Each micro-motion stage position detection device includes a light source module and a position measurement module arranged opposite to each other. The light source module is connected to the position detection module through a corresponding flexible circuit board. The light source module of each micro-motion stage position detection device is installed at a different given position of the micro-motion stage, and the position detection module is installed on the coarse motion stage. Among them, for each micro-motion stage position detection device: The light source module generates an annular Gaussian beam and is incident on the position measurement module; The position measurement module generates a corresponding photogenerated current signal in response to the received annular Gaussian light beam, and performs voltage conversion processing on the photogenerated current signal to obtain voltage data and send it to the position calculation module; The position calculation module determines the position information of the fine-motion stage relative to the coarse-motion stage based on the voltage data corresponding to each fine-motion stage position detection device.

2. The micro-motion stage position measurement system according to claim 1, characterized in that: The micro-motion stage position measurement system also includes an analog-to-digital conversion module, the light source module includes a light source and a collimating lens, the position measurement module includes a two-dimensional position sensitive detector and a board unit connected thereto, the light source is connected to the board unit via a corresponding flexible circuit board, the board unit and the two-dimensional position sensitive detector are fixedly mounted on the coarse motion stage, the light source module and the corresponding two-dimensional position sensitive detector are arranged opposite to each other, A light shield is installed on the two-dimensional position sensitive detector. The two-dimensional position sensitive detector is square. The center points of the four sides of the P layer of the two-dimensional position sensitive detector are respectively connected to corresponding output electrodes. The board unit drives the light source and the two-dimensional position sensitive detector. Among them, for each micro-motion stage position detection device: The light emitted by the light source driven by the board power supply is transformed into a ring-shaped Gaussian beam through the collimating lens, and then incident on the effective detection area corresponding to the two-dimensional position sensitive detector, forming an incident light spot in the effective detection area; The two-dimensional position sensitive detector generates a corresponding photocurrent signal at each output electrode in response to the incident annular Gaussian light beam and outputs the signal to the board unit; The board unit performs voltage conversion processing on the photocurrent signal generated by each output electrode, obtains voltage data corresponding to the micro-motion stage position detection device and sends it to the analog-to-digital conversion module; The analog-to-digital conversion module performs analog-to-digital conversion processing on the voltage data to obtain target voltage data and inputs the target voltage data into the position calculation module; The position calculation module determines the position information of the fine-motion stage relative to the coarse-motion stage based on the target voltage data corresponding to each fine-motion stage position detection device.

3. The micro-motion stage position measurement system according to claim 2, characterized in that: The board unit includes a transimpedance amplifier component, a differential amplifier component and a voltage summing component. The output electrodes include two output cathodes arranged opposite to each other in the horizontal direction and two output anodes arranged opposite to each other in the vertical direction of the two-dimensional position sensitive detector. The voltage data includes a horizontal differential voltage corresponding to the two output cathodes, a vertical differential voltage corresponding to the two output anodes and a target debiasing voltage. The target debiasing voltage is a debiased horizontal differential voltage output by the two output cathodes or a debiased vertical differential voltage output by the two output anodes. Among them, for each micro-motion stage position detection device: The transimpedance amplifier component receives the photocurrent signal from each output electrode on the corresponding two-dimensional position sensitive detector, converts it into a voltage processing signal corresponding to each output electrode after processing, and inputs it into the corresponding differential amplifier component; The transimpedance amplifier component inputs the voltage processing signals corresponding to the two output cathodes or the voltage processing signals corresponding to the two output anodes into the corresponding voltage summing component; The differential amplifier component outputs a horizontal differential voltage corresponding to two output cathodes and a vertical differential voltage corresponding to two output anodes to the analog-to-digital conversion module based on the voltage processing signal corresponding to each output electrode; The voltage summing component outputs the target de-bias voltage to the analog-to-digital conversion module based on the voltage processing signals corresponding to the two output cathodes or the voltage processing signals corresponding to the two output anodes; The analog-to-digital conversion module performs analog-to-digital conversion processing on the horizontal differential voltage, the vertical differential voltage and the target de-biased voltage, and then outputs the horizontal processing voltage, the vertical processing voltage and the de-biased sum voltage to the position calculation module; The position calculation module determines, for each fine-motion stage position detection device, the two-dimensional position information of the incident light spot generated by the light source module on the two-dimensional position sensitive detector relative to the coarse motion stage according to the horizontal processing voltage, the vertical processing voltage and the debiased sum voltage; The position calculation module obtains the position information of the fine-motion stage relative to the coarse-motion stage after solving the position measurement solution matrix based on the two-dimensional position information corresponding to each fine-motion stage position detection device.

4. The micro-motion stage position measurement system according to claim 3, characterized in that: The transimpedance amplification component includes a transimpedance amplification circuit correspondingly connected to each output electrode, and the transimpedance amplification circuit includes a current-to-voltage structure and a bias current compensation structure. Among them, for the transimpedance amplifier circuit: If the transimpedance amplifier circuit is connected to the output cathode, one end of the bias current compensation structure is connected to a given single power supply, and if the transimpedance amplifier circuit is connected to the output anode, one end of the bias current compensation structure is grounded; The other end of the bias current compensation structure is respectively connected to the inverting input end of the current-to-voltage structure and the output electrode corresponding to the two-dimensional position sensitive detector, the non-inverting input end of the current-to-voltage structure is connected to the common mode voltage, and the output end of the current-to-voltage structure is connected to the differential amplifier component as the output end of the transimpedance amplifier circuit; The common-mode voltage includes a first common-mode voltage and a second common-mode voltage. If the transimpedance amplifier circuit is connected to the output cathode, the non-inverting input end of the current-to-voltage structure corresponding to the transimpedance amplifier circuit is connected to the first common-mode voltage. If the transimpedance amplifier circuit is connected to the output anode, the non-inverting input end of the current-to-voltage structure corresponding to the transimpedance amplifier circuit is connected to the second common-mode voltage.

5. The micro-motion stage position measurement system according to claim 4, characterized in that: The differential amplifier component includes an anode differential amplifier circuit corresponding to the output anode and a cathode differential amplifier circuit corresponding to the output cathode. Wherein, the first input end of the anode differential amplifier circuit is connected to the output end of the transimpedance amplifier circuit corresponding to one of the output anodes corresponding to the two-dimensional position sensitive detector, the second input end of the anode differential amplifier circuit is connected to the output end of the transimpedance amplifier circuit corresponding to another input anode corresponding to the two-dimensional position sensitive detector, the common mode voltage input end of the anode differential amplifier circuit is connected to the third common mode voltage, the positive differential output end and the negative differential output end of the anode differential amplifier circuit are respectively connected to the analog-to-digital conversion module, and the positive differential output end and the negative differential output end of the anode differential amplifier circuit respectively output the vertical differential voltages corresponding to the two output anodes on the two-dimensional position sensitive detector; The first input end of the cathode differential amplifier circuit is connected to the output end of the transimpedance amplifier circuit corresponding to one of the input cathodes of the two-dimensional position sensitive detector, the second input end of the cathode differential amplifier circuit is connected to the output end of the transimpedance amplifier circuit corresponding to another input cathode of the two-dimensional position sensitive detector, the common mode voltage input end of the cathode differential amplifier circuit is connected to the third common mode voltage output end, the positive differential output end and the negative differential output end of the cathode differential amplifier circuit are respectively connected to the analog-to-digital conversion module, and the anode differential output end and the cathode differential output end of the cathode differential amplifier circuit respectively output the horizontal differential voltages corresponding to the two output cathodes on the two-dimensional position sensitive detector.

6. The micro-motion stage position measurement system according to claim 5, characterized in that: The differential amplifier circuit includes a first voltage-dividing resistor, a second voltage-dividing resistor, a third voltage-dividing resistor, a fourth voltage-dividing resistor and a differential amplifier structure. The first voltage-dividing resistor has the same specification as the third voltage-dividing resistor, and the second voltage-dividing resistor has the same specification as the fourth voltage-dividing resistor. One end of the first voltage-dividing resistor is used as a first input end of the differential amplifier circuit, the other end of the first voltage-dividing resistor is connected to one end of the second voltage-dividing resistor and the inverting input end of the differential amplifier structure, and the other end of the second voltage-dividing resistor is connected to one of the output ends of the differential amplifier structure and used as a positive differential output end of the differential amplifier circuit; One end of the third voltage-dividing resistor is used as the second input end of the differential amplifier circuit, the other end of the third voltage-dividing resistor is connected to one end of the fourth voltage-dividing resistor and the non-inverting input end of the differential amplifier structure, and the other end of the fourth voltage-dividing resistor is connected to the other output end of the differential amplifier structure and used as the negative differential output end of the differential amplifier circuit; The common mode voltage input terminal of the differential amplifier circuit is connected to a third common mode voltage.

7. The micro-motion stage position measurement system according to any one of claims 1 to 6, characterized in that: The board module also includes a common-mode voltage generating circuit, which includes a first common-mode voltage dividing structure, a second common-mode voltage dividing structure, a third common-mode voltage dividing structure, a fourth common-mode voltage dividing structure and a fifth common-mode voltage dividing structure. Among them, one end of the first common-mode voltage-dividing structure is connected to one end of the second common-mode voltage-dividing structure and used as the first common-mode power supply output end, the other end of the second common-mode voltage-dividing structure is respectively connected to one end of the third common-mode voltage-dividing structure and the ground, the other end of the third common-mode voltage-dividing structure is connected to one end of the fourth common-mode voltage-dividing structure and used as the second common-mode power supply output end, the other end of the fourth common-mode voltage-dividing structure is connected to one end of the fifth common-mode voltage-dividing structure and used as the third common-mode power supply output end, and the other end of the fifth common-mode voltage-dividing structure is connected to the other end of the first common-mode voltage-dividing structure and then connected to a given single power supply.

8. The micro-motion stage position measurement system according to claim 3, characterized in that: The voltage summing component includes an in-phase summing structure, an inverting feedback structure and a differential processing structure. The feedback generated by the in-phase summing structure is equal to the feedback generated by the inverting feedback structure. The first connection end and the second connection end of the in-phase summing structure are respectively connected to the output ends of the transimpedance amplifier circuit corresponding to the two output cathodes or the output ends of the transimpedance amplifier circuit corresponding to the two output anodes, and the output end of the in-phase summing structure is connected to the in-phase input end of the differential processing structure; The first connection end of the inverting feedback structure is connected to a given single power supply, the second connection end of the inverting feedback structure is grounded, and the output end of the inverting feedback structure is connected to the inverting input end of the differential processing structure; The positive differential output terminal and the negative differential output terminal of the differential processing structure are connected to the analog-to-digital conversion module, and the positive differential output terminal and the negative differential output terminal of the differential processing structure output the target de-biasing voltage to the analog-to-digital conversion module.

9. The micro-motion stage position measurement system according to claim 3, characterized in that: The board unit also includes a photoelectric current servo circuit and a light source driving circuit. The light source is connected to the light source driving circuit via a flexible circuit board. The light source driving circuit includes a feedback circuit, a current regulating circuit and a light source voltage stabilizing circuit. Among them, the inverting input terminal of the light source current servo circuit is connected to the positive output terminal or the negative output terminal of the voltage summing component, the inverting input terminal of the light source current servo circuit is connected to the cathode of the light source, the output terminal of the light source current servo circuit is connected to the input terminal of the feedback circuit, the output terminal of the feedback circuit is respectively connected to the adjustment signal feedback terminal of the current regulation circuit and the cathode of the light source, the power supply terminal of the current regulation circuit is connected to a given single power supply, the output terminal of the current regulation circuit is connected to the anode of the light source, and the light source voltage stabilizing circuit is connected in parallel between the anode and cathode of the light source component.

10. The micro-motion stage position measurement system according to claim 3, characterized in that: The position calculation module determines the two-dimensional position information of the incident light spot corresponding to each micro-motion stage position detection device by the following formula: In this formula, X m It indicates the horizontal position of the incident light spot generated on the two-dimensional position sensitive detector relative to the center point of the two-dimensional position sensitive detector. m V represents the vertical position of the incident light spot generated on the 2D position sensitive detector relative to the center point of the 2D position sensitive detector. sum_pure Represents the debiased summed voltage output by the analog-to-digital conversion module, V xF Represents the horizontal processing voltage output by the analog-to-digital conversion module, V yF Indicates the vertical processing voltage output by the analog-to-digital conversion module; V xP Represents the horizontal differential voltage output from the positive differential output terminal of the cathode differential amplifier circuit, V xN Represents the horizontal differential voltage outputted from the negative differential output terminal of the cathode differential amplifier circuit, V yP Represents the vertical differential voltage output from the positive differential output terminal of the anode differential amplifier circuit, V yN Represents the vertical differential voltage outputted from the negative differential output terminal of the anode differential amplifier circuit, V sum_pure_p The voltage at the positive differential output of the voltage summing component, V sum_pure_N The voltage at the negative differential output terminal of the voltage summing component, V xF 、V yF and V sum_pure Output from the analog-to-digital conversion module.

11. The micro-motion stage position measurement system according to claim 3, characterized in that: The position calculation module determines the position information of the fine motion stage relative to the coarse motion stage by: Obtaining spatial position information of the light source in each micro-motion stage position detection device in a spatial coordinate system with the center of the micro-motion stage as the origin coordinate; Based on the spatial position information corresponding to each fine-motion stage position detection device, a position measurement solution matrix is ​​established, wherein the position measurement solution matrix describes the solution relationship between the two-dimensional position information corresponding to the plurality of fine-motion stage position detection devices and the six-degree-of-freedom position information of the fine-motion stage relative to the coarse-motion stage; According to the position measurement solution matrix and the two-dimensional position information corresponding to each fine-motion stage position detection device, the six-degree-of-freedom position information of the fine-motion stage relative to the coarse-motion stage is determined.

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