WO2020001557A1

WO2020001557A1 - Grid error measurement method and measurement device, and optical equipment

Info

Publication number: WO2020001557A1
Application number: PCT/CN2019/093367
Authority: WO
Inventors: 宋涛; 徐兵; 李煜芝
Original assignee: 上海微电子装备（集团）股份有限公司
Priority date: 2018-06-28
Filing date: 2019-06-27
Publication date: 2020-01-02
Also published as: CN110657743B; CN110657743A; TWI739122B; TW202018251A

Abstract

A grid error measurement method and a measurement device, and optical equipment. The grid error measurement method comprises: acquiring first actual position information about a preset alignment measurement mark on a substrate by means of a position measurement system in optical equipment, the substrate being horizontally adsorbed on a substrate adsorbing table of the optical equipment at a first angle, and a first direction being perpendicular to the second direction (S110); acquiring second actual position information about the preset alignment measurement mark by means of the position measurement system, the substrate being horizontally absorbed on the substrate adsorbing table at a second angle, and the second angle being different from the first angle (S120); and calculating the grid error of the position measurement system according to the first actual position information, the second actual position information, and the standard position information of the preset alignment measurement mark (S130).

Description

Method, device and optical equipment for measuring grid error

This application claims priority from a Chinese patent application filed with the Chinese Patent Office on June 28, 2018 with application number 201810688910.1, the entire contents of which are incorporated herein by reference.

Technical field

Embodiments of the present application relate to a position measurement technology, for example, to a method for measuring a grid error, a measurement device, and an optical device.

Background technique

Position measuring equipment or precision motion equipment in the exposure machine, an interferometer or a grating measuring system will be arranged on each measuring axis for positioning control and measurement of the motion table. However, the position measurement system itself also has measurement errors, which can cause deviations between the actual position and the ideal position of the motion table, resulting in inaccurate measurements.

Generally, the grid error (the deviation of the actual deformation of a certain point horizontally from its ideal position is connected to form a checkered grid arranged in space) to represent the position measurement system's measurement of the horizontal error. Grid errors need to be compensated or calibrated using certain methods and methods to make the final position measurement or movement position accurate.

At present, most of the position measurement equipment on the market uses large mask plates or reference plates for grid correction. However, the first is the inconvenience of calibration use and maintenance. It is necessary to manually upload the mask plates at different positions on the motion table multiple times to calibrate local errors one by one. And the mask also needs to be maintained separately. Second, as the industry develops, especially in the field of flat panel display, the size of the substrate is also increasing. The size of subsequent masks needs to increase simultaneously, and the cost will inevitably increase. There are limitations. Another grid calibration scheme uses the position model of the position measurement system (interferometer, grating ruler). It needs to collect a large range of position data of the motion table under different attitudes (including rotation, tilt, etc.) for mathematical fitting calculations. However, The motion stage of most position measurement equipment generally can only set a single degree of freedom motion. Correlation data of multiple degrees of freedom cannot be obtained, resulting in a position model that cannot be solved. Therefore, grid errors cannot be calculated and calibrated.

Summary of the invention

The following is an overview of the topics detailed in this article. This summary is not intended to limit the scope of protection of the claims.

The application provides a grid error measurement method, a measurement device, and an optical device. The grid error is calculated, and the measurement position of the position measurement system is calibrated to make the final position measurement or movement position accurate.

In a first aspect, an embodiment of the present application provides a method for measuring a grid error, including: obtaining first actual position information of a preset alignment measurement mark on a substrate through a position measurement system in an optical device, wherein, The substrate is provided with a plurality of alignment measurement marks arranged in an array along the first direction and the second direction to form a measurement grid. The substrate is horizontally adsorbed on the substrate adsorption table of the optical device at a first angle. The first direction and the second direction are perpendicular to each other; and acquiring the second actual position information of the preset alignment measurement mark through the position measurement system, wherein the substrate is horizontally adsorbed on the second angle at a second angle. On the substrate adsorption table, the second angle is different from the first angle; and is calculated based on the first actual position information, the second actual position information, and standard position information of the preset alignment measurement mark. The grid error of the position measurement system.

In a second aspect, an embodiment of the present application further provides a device for measuring a grid error, including: a first actual position information module configured to obtain a preset alignment measurement mark on a substrate through a position measurement system in an optical device; The first actual position information, wherein the substrate is provided with a plurality of alignment measurement marks arranged in an array along the first direction and the second direction to form a measurement grid, and the substrate is horizontally adsorbed at a first angle on the substrate. The first direction is perpendicular to the second direction on the substrate adsorption stage of the optical device; a second actual position information acquisition module is configured to acquire the preset alignment measurement mark through the position measurement system The second actual position information, wherein the substrate is horizontally adsorbed on the substrate adsorption table at a second angle, the second angle is different from the first angle; the grid error calculation module is configured to be based on the The first actual position information, the second actual position information, and the standard position information of the preset alignment measurement mark calculate a grid error of the position measurement system.

According to a third aspect, an embodiment of the present application further provides an optical device including the grid error measuring device according to the second aspect.

Other aspects can be understood after reading and understanding the accompanying drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural diagram of a position measurement device according to an embodiment of the present application; FIG.

2 is a flowchart of a method for measuring a grid error according to an embodiment of the present application;

3 is a schematic diagram of a base structure provided by an embodiment of the present application;

FIG. 4 is a graphic structure of several alignment measurement marks according to an embodiment of the present application; FIG.

5 is a schematic diagram of a rotation error provided by an embodiment of the present application;

6 is a schematic diagram of a non-orthogonality error provided by an embodiment of the present application;

7 is a schematic diagram of a translation error provided by an embodiment of the present application;

8 is a flowchart of another method for measuring a grid error provided by an embodiment of the present application;

FIG. 9 is a schematic diagram of a rotation error provided by an embodiment of the present application; FIG.

FIG. 10 is a flowchart of another method for measuring a grid error according to an embodiment of the present application; FIG.

11 is a schematic diagram of a non-orthogonality error provided by an embodiment of the present application;

FIG. 12 is a flowchart of another raster error measurement method according to an embodiment of the present application; FIG.

13 is a schematic diagram of a translation error provided by an embodiment of the present application;

FIG. 14 is a structural block diagram of a raster error measuring device according to an embodiment of the present application.

detailed description

The following describes the present application in detail with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, rather than limiting the present application. It should also be noted that, for convenience of description, the drawings only show a part of the structure related to the present application, but not the entire structure.

FIG. 1 is a schematic structural diagram of a position measurement device according to an embodiment of the present application. It should be noted that the position measurement device in FIG. 1 is only a specific example provided by this embodiment, and is not a limitation on the present application.

Referring to FIG. 1, the position measuring device may include: a complete machine air bath constant temperature control system 1, which includes a temperature measurement sensor and a temperature controlled air bath unit to ensure the stability of the internal environment of the whole machine; a complete machine protection frame 2 for providing protection And thermal insulation function; optical measurement stage 3, used to carry optical measurement sensors and perform horizontal X and vertical Z motion control, wherein the optical measurement stage 3 is equipped with a coarse position measurement sensor 7, precise position measurement and graphics Coarse measurement sensor 8, precise position measurement and graphic precise measurement sensor 9, first height measurement sensor 10 is installed on position precise measurement and graphic coarse measurement sensor 8, second height measurement sensor 11 is installed on position precise measurement and graphic measurement sensor 9 Upper; optical measurement stage movement guide 4 and guide rail support 5; X-direction interferometer measurement system 6 for measuring the movement position of the optical measurement stage; base stage 12 for carrying the measurement base and performing horizontal Y-direction motion control ; Substrate adsorption stage 13 for adsorption measurement substrate, with a substrate constant temperature cooling system; substrate carrier movement guide 14; Y-direction interferometer Measurement system 15 for measuring the movement position of the substrate carrier; marble support table 16 for supporting the substrate carrier and reducing the momentum of the substrate carrier during the measurement process; shock absorption system 17 for providing the carrier during the measurement process The vibration elimination effect of the movement.

It can be understood that, in consideration of subsequent requirements, the substrate needs to be horizontally adsorbed on the substrate adsorption table 13 at different angles (for example, 0 degrees, 90 degrees, and 180 degrees). In order to facilitate measurement, the substrate 100 may be circular or square. By nature, it can be cut by a microtome. When the substrate 100 is square, the side length of the substrate 100 can be set to be shorter than or equal to the short side of the substrate stage 12 to ensure that the substrate 100 is within the range of the substrate stage 12.

FIG. 2 is a flowchart of a method for measuring a grid error according to an embodiment of the present application. This method is suitable for professional measurement equipment that requires position measurement calibration, such as the above-mentioned position measurement equipment. Referring to FIG. 2, a method for measuring a grid error according to the first embodiment of the present application includes steps S110 to S130.

In step S110, the first actual position information of the preset alignment measurement mark on the substrate is acquired through a position measurement system in the optical device, wherein a plurality of array arrangements are arranged on the substrate along the first direction and the second direction. The measurement marks are aligned to form a measurement grid. The substrate is horizontally adsorbed on the substrate adsorption table of the optical device at a first angle, and the first direction is perpendicular to the second direction.

The optical equipment may be a lithography machine, an exposure machine, or other professional measurement equipment that requires position measurement calibration. The position measurement system in the optical equipment can perform positioning control and measurement on the motion table.

The specific structure of the position measurement system is not limited in this application. In one embodiment, the position measurement system is an interferometer measurement system, a laser triangle, or a laser displacement sensor. Position measurement systems can also be other structures, such as precision motion equipment in exposure machines.

Continuing to refer to FIG. 1, the movement direction of the optical measurement stage frame in the position measurement system can be defined as the X direction, the direction perpendicular to the X direction on the horizontal plane is the Y direction, and the vertical direction is the Z direction, and an XYZ three-dimensional coordinate system is established.

In an embodiment, the first direction is parallel to the X axis in the preset coordinate system, and the second direction is parallel to the Y axis in the preset coordinate system; or the first direction is parallel to Y in the preset coordinate system. Axis, the second direction is parallel to the X axis in the preset coordinate system.

FIG. 3 is a schematic diagram of a base structure provided by an embodiment of the present application. Referring to FIG. 3, a plurality of alignment measurement marks 200 arranged in an array along the first direction and the second direction may be provided on the substrate 100 to form a measurement grid. Wherein, the intervals between the plurality of alignment measurement marks 200 arranged along the first direction (or the second direction) are the same, but the intervals between the alignment measurement marks 200 arranged along the first direction are the same as those along the first The spacing between the alignment measurement marks 200 arranged in two directions is different.

In order to measure accurately, to avoid measurement errors caused by the shape of the alignment measurement mark 200 when the substrate is adsorbed on the substrate adsorption table 13 at different angles, in one embodiment, the alignment alignment mark 200 is a center-symmetrical shape. .

It should be noted that the alignment measurement marks 200 are arranged in an array along the first direction and the second direction, and the spacing between the plurality of alignment measurement marks 200 arranged along the first direction or the second direction may be the same or Can be different. The spacing between the alignment measurement marks 200 can be set according to the actual situation. In one embodiment, the spacing can be set at about 4-8 mm. This application does not limit the alignment positions of the alignment measurement marks 200 in the first direction and the second direction. For example, each alignment measurement mark 200 may be set to be center-rotationally distributed around the center of the substrate 100.

FIG. 4 is a graphic structure of several alignment measurement marks provided in the embodiment of the present application. Referring to FIG. 4, the alignment measurement marks 200 can be set to be distributed symmetrically at 180 ° and 90 ° centers. The alignment measurement mark 200 can be made by exposure with an exposure machine.

Taking the position measuring device provided in FIG. 1 as an optical device as an example, the substrate 100 is set to be horizontally adsorbed on the substrate adsorption table 13 of the optical device at a first angle, and a preset alignment measurement on the substrate is obtained through the position measurement system in the optical device. Marked first actual position information.

In step S120, the second actual position information of the preset alignment measurement mark is acquired by the position measurement system, wherein the substrate is horizontally adsorbed on the substrate adsorption table at a second angle, and the second angle is different from the first angle.

Considering that the movement stage of most position measurement equipment generally can only set a single degree of freedom movement, correlation data of multiple degrees of freedom cannot be obtained. Therefore, in this embodiment, it is only required that the substrate is adsorbed on the substrate at different angles in the horizontal direction. It can be mounted on the adsorption table, it is easy to operate, and it has low requirements on the degree of freedom of the position measuring equipment. It is suitable for the grid error measurement of various position measuring equipment.

In step S130, the grid error of the position measurement system is calculated according to the first actual position information, the second actual position information, and the standard position information of the preset alignment measurement mark.

Among them, the grid error is a measurement error caused by the position measurement system itself. Therefore, the standard position information of the alignment measurement mark can be recorded in advance, and only the preset alignment measurement mark used in the calculation of the grid error can be recorded. The standard position information can also record the standard position information of all the alignment measurement marks set on the substrate.

It should be noted that the grid error characterizes the horizontal measurement error of the position measurement system. Considering that the movement stage of most position measurement systems can only set a single degree of freedom movement, in order to avoid collecting correlation data of multiple degrees of freedom In this application, the substrate is set to be horizontally adsorbed on the substrate adsorption table at different angles, and the actual position information of the alignment measurement marks at different adsorption angles is collected, and the actual position information at different angles is calculated by a preset algorithm to obtain a position measurement system. Grid error.

The method for measuring the grid error provided by this embodiment does not require a large mask plate, and the calculation method is simple. The measurement position of the position measurement system can be calibrated to make the final position measurement or the movement position accurate, and it is not necessary to collect the motion table. A large range of position data under different attitudes (including rotation, tilt, etc.) are mathematically fitted and calculated, which avoids the situation that the position model cannot be solved because correlation data of multiple degrees of freedom cannot be obtained.

Currently, there are three main types of grid errors: rotation errors, non-orthogonal errors, and translation errors.

First, the rotation error is caused by an installation error of a position measurement system (for example, an interferometer measurement system), which may have an impact on position measurement or motion positioning. The rotation error is that the optical measurement stage has a certain offset in that direction during the movement in the first direction (or the second direction), and the value of the offset changes linearly.

FIG. 5 is a schematic diagram of a rotation error provided by an embodiment of the present application. Referring to FIG. 5, for example, when the stage (optical measurement stage or base stage) moves in the Y direction, the rotation amount Rz of the actual position of the stage 301 relative to the expected position 302 of the stage at the same Y position is The linear change will cause the actual position 201 of the alignment measurement mark 200 to have a linear change offset dy in the Y direction relative to its standard position 202, which is an error of the rotation degree of the table grid Y direction. Similarly, when the optical measurement stage is moving in the X direction, the rotation error will cause the position measurement or movement to be positioned linearly relative to the standard position 202 of each alignment measurement mark 200 in the X direction. s position.

Secondly, the non-orthogonal error is caused by the non-vertical guide rails of the moving table, which will affect the position measurement. The non-orthogonality error is that the optical measurement stage has a certain offset in another direction during the movement in the first direction (or the second direction), and the value of the offset changes linearly.

FIG. 6 is a schematic diagram of a non-orthogonality error provided by an embodiment of the present application. Referring to FIG. 6, for example, when the stage moves in the Y direction, the actual position 201 of the alignment measurement mark 200 relative to its standard position 202 has an offset dx that changes linearly in the X direction. Is the non-orthogonality error of the moving table grid Y direction. Similarly, when the optical measurement stage is moving in the X direction, the non-orthogonality error in the X direction will cause the position measurement or movement to be positioned at an offset in the Y direction relative to the standard position 202 of each alignment measurement mark 200. The position where dy changes linearly.

Finally, the translation error is mainly caused by the unevenness of the moving guide or the mirror surface in the position measurement system. For example, the unevenness of the plane mirror of the interferometer will affect the position measurement. The translation error is that during the movement of the carrier in the first direction (or the second direction), the same offset value is obtained in the same direction in the other direction, and the offset value varies and is irregular when the value is different.

FIG. 7 is a schematic diagram of a translation error provided by an embodiment of the present application. Referring to FIG. 7, for example, during the movement of the optical measurement stage in the Y direction, the actual position 201 of the alignment measurement mark 200 has the same offset dx at the same Y position relative to its standard position 202, but The offset dx at different Y positions varies and is irregular. Similarly, when the optical measurement stage is moving in the X direction, the translation error in the X direction will cause the position measurement to have the same offset dy at the same X position relative to the standard position 202 of each alignment measurement mark 200. The offset dy of different X positions varies and is irregular.

Based on the above embodiments, this embodiment provides another method for measuring grid errors. FIG. 8 is a flowchart of another method for measuring a grid error according to an embodiment of the present application. Referring to FIG. 8, when the measured grid error is a rotation error, the method for measuring the grid error includes steps S210, S220, S231, S232, and S233.

In step S210, the first actual position information of the preset alignment measurement mark on the substrate is acquired through a position measurement system in the optical device, wherein the substrate is horizontally adsorbed on the substrate adsorption table of the optical device at a first angle, and the preset The alignment measurement marks include at least two columns of alignment measurement marks in the second direction.

It should be noted that, since the rotation error is the offset that the carrier changes linearly in a certain direction during the movement of the stage in a certain direction, it is necessary to calculate a plurality of sets of offsets along the direction. For example, in order to measure the rotation error in the Y direction, at least two columns of alignment measurement marks along the Y direction may be selected, and the offsets corresponding to the alignment measurement marks in different columns (that is, different X values) when the same Y value is calculated are selected. The shift amount dy is used to calculate the respective shift amount dy for each Y value, thereby obtaining the rotation error in the Y direction.

Similarly, in order to measure the rotation error in the X direction, at least two rows of alignment measurement marks in the X direction may be selected.

In step S220, the second actual position information of the preset alignment measurement mark is acquired by the position measurement system, wherein the substrate is horizontally adsorbed on the substrate adsorption table at a second angle, the first angle is 0 degree, and the second angle is 180 degree.

It should be noted that since there may be rotation errors between the grid of the moving table and the grid of the measuring substrate itself, the substrate is set to be adsorbed on the substrate adsorption table at 0 degrees and 180 degrees, and the substrate is adsorbed at 0 degrees and 180 degrees, respectively. The measurement result of time is the superposition of the rotation error between the two, and the rotation error in the position measurement system can be calculated more accurately based on the calculation results of the two.

In step S231, according to the first actual position information and the standard position information of the preset alignment measurement mark, a first grid rotation degree of the measurement grid is determined when the substrate is adsorbed on the substrate adsorption table at a level of 0 degrees.

In step S232, according to the second actual position information and the standard position information of the preset alignment measurement mark, a second grid rotation degree of the measurement grid is determined when the substrate is adsorbed on the substrate adsorption table at a 180-degree level.

In step S233, a grid rotation error in the second direction of the position measurement system is calculated based on the first grid rotation and the second grid rotation.

It should be noted that it is necessary to calculate the offset and grid rotation of the substrate at different angles, and determine the grid rotation error by measuring the grid rotation twice.

In an embodiment, step S231 includes: calculating a first rotation amount of the alignment measurement mark pair according to the first actual position information and the standard position information of the alignment measurement mark pair, wherein the alignment measurement mark pair Including two alignment measurement marks located in the same row in the first direction, any first rotation amount Rotyn_0 satisfies: Rotyn_0 = (pos_yj_0-pos_yi_0) / (xj-xi), and pos_yi_0 is the alignment amount at 0 degrees The coordinate value of the first actual position information of the first alignment measurement mark in the measurement mark pair in the first direction. Pos_yj_0 is the first actual position of the second alignment measurement mark in the alignment measurement mark pair at 0 degrees. The coordinate value of the information in the first direction, xi is the coordinate value of the standard position information of the first alignment measurement mark in the second direction, and xj is the standard position information of the second alignment measurement mark in the second direction. Coordinate value according to the first rotation amount and standard position information of a plurality of different alignment measurement mark pairs, and the first grid rotation degree is calculated by linear fitting, wherein the linear fitting formula satisfies: Rotyn_0 = K0 × (yi + yj) / 2 + dRotyn_0, K0 is the first grid rotation , Yi is the coordinate value of the standard position information of the first alignment measurement mark in the first direction, and yj is the standard position information of the second alignment measurement mark in the first direction. Coordinate value, dRotyn_0 is the fitted residual at 0 degrees.

Step S232 includes: calculating a second rotation amount of the alignment measurement mark pair according to the second actual position information and the standard position information of the alignment measurement mark pair. Any of the second rotation amounts Rotyn_180 satisfies: Rotyn_180 = ( pos_yj_180-pos_yi_180) / (-xj + xi), pos_yi_180 is the coordinate value in the first direction of the first actual position information of the first alignment measurement mark in the alignment measurement mark pair at 180 degrees, and pos_yj_180 is 180 degrees The coordinate values of the first actual position information of the second alignment measurement mark pair in the first direction in the alignment measurement mark pair described below; according to the second rotation amount and Standard position information, linear fitting to calculate the second grid rotation, wherein the linear fitting formula satisfies: Rotyn_180 = K180 × (-yi-yj) / 2 + dRotyn_180, K180 is the second grid rotation, dRotyn_180 is the fitting residual at 180 degrees; correspondingly, the grid rotation error K_ws_z in the second direction in S233 satisfies the following formula: K_ws_z = (K0-K180) / 2.

FIG. 9 is a schematic diagram of a rotation error provided by an embodiment of the present application. Referring to FIG. 9, for example, taking the first direction as the X direction (the first direction is parallel to the X axis) and the second direction as the Y direction as an example (the second direction is parallel to the Y axis), the Y is measured by the above grid error measurement method. Rotation to grid error.

First, at least two columns of alignment measurement marks in the Y direction are selected as preset alignment measurement marks, and the standard position information 202 of each preset alignment measurement mark can be recorded in advance. For example, Mark1 and Mark2 are in the X direction. A pair of alignment measurement mark pairs of the same Y value. Mark3 and Mark4 are another pair of alignment measurement mark pairs of the same Y value in the X direction. The standard position information of Mark1 is recorded as (x1, y1). The standard position information is (x2, y2), and the standard position information for sequentially recording a plurality of different alignment measurement mark pairs is (x3, y3), (x4, y4), ... (xN, yN).

Secondly, referring to FIG. 9 (a), the substrate is adsorbed on the substrate adsorption table of the optical device at a level of 0 degrees, and the first actual position information of the preset alignment measurement mark is sequentially measured. Exemplarily, the first actual position information of Mark1 is recorded as (pos_x1_0, pos_y1_0), the first actual position information of Mark2 is (pos_x2_0, pos_y2_0), and the first actual position information of multiple different alignment measurement mark pairs are sequentially recorded. Are (pos_x3_0, pos_y3_0), (pos_x4_0, pos_y4_0) ... (pos_xN_0, pos_yN_0).

Through Rotyn_0 = (pos_yj_0-pos_yi_0) / (xj-xi), calculate the first rotation amount Rotyn_0 corresponding to each alignment measurement mark pair:

Roty12_0 = (pos_y2_0-pos_y1_0) / (x2-x1);

Roty34_0 = (pos_y4_0-pos_y3_0) / (x4-x3);

...

Roty (N-1) N_0 = (pos_yN_0-pos_y (N-1) _0) / (xN-x (N-1));

Where N is an even number. According to the obtained N / 2 rotation amounts and the position of y in the standard position information, a linear fitting is performed to calculate the first grid rotation degree Rotyn_0 at 0 degrees:

Rotyn_0 = K0 × yn_0 + dRotyn_0;

Among them, Rotyn_0 takes Roty12_0, Roty34_0, ... or Roty (N-1) N_0; yn_0 takes (y1 + y2) / 2, (y3 + y4) / 2, ... or (y (N-1) + yN) / 2 , DRotyn_0 is the fitted residual;

That is according to:

Roty12_0 = K0 × (y1 + y2) / 2 + dRoty12_0;

Roty34_0 = K0 × (y3 + y4) / 2 + dRoty34_0;

...

Roty (N-1) N_0 = K0 × (y (N-1) + yN) / 2 + dRoty (N-1) N_0;

By compensating the respective fitting residuals, a linear fit yields the first grid rotation K0 at 0 degrees.

Since there may be rotation errors between the grid of the moving table and the grid of the measurement base itself, 0 degrees is the obtained first grid rotation K0, which is the superposition of the rotation errors of the two:

Where K0 = (K_ws_y + K_plate_y);

K_ws_y is the grid rotation error of the motion table, and K_plate_y is the grid rotation error of the measurement base itself.

Then, referring to FIG. 9 (b), the substrate is adsorbed on the substrate adsorption table of the optical device at a 180-degree level, and the second actual position information of the preset alignment measurement mark is sequentially measured. Exemplarily, the second actual position information of Mark1 is recorded as (pos_x1_180, pos_y1_180), the second actual position information of Mark2 is (pos_x2_180, pos_y2_180, and the second actual position information of multiple different alignment measurement mark pairs is sequentially recorded as (pos_x3_180, pos_y3_180), (pos_x4_180, pos_y4_180) ... (pos_xN_180, pos_yN_180).

Through Rotyn_180 = (pos_yj_0-pos_yi_0) / (-xj + xi), calculate the first rotation amount Rotyn_180 corresponding to each alignment measurement mark pair:

Roty12_180 = (pos_y2_180-pos_y1_180) / (-x2 + x1);

Roty34_180 = (pos_y4_180-pos_y3_180) / (-x4 + x3);

...

Roty (N-1) N_180 = (pos_yN_180-pos_y (N-1) _180) / (-xN + x (N-1));

According to the obtained N / 2 rotation amounts and the position of y in the standard position information, a linear fit is performed to calculate the second grid rotation degree Rotyn_180 at 180 degrees:

Rotyn_180 = K180 × yn_180 + dRotyn_180;

Among them, Rotyn_180 takes Roty12_180, Roty34_180 ... or Roty (N-1) N_180; yn_180 takes-(y1 + y2) / 2,-(y3 + y4) / 2 ... or-(y (N-1) + yN) / 2, dRotyn_180 is the fitting residual;

That is according to:

Roty12_180 =-(y1 + y2) / 2 × K180 + dRoty12_180;

Roty34_180 =-(y3 + y4) / 2 × K180 + dRoty34_180;

...

Roty (N-1) N_180 =-(y (N-1) + yN) / 2 × K180 + dRoty (N-1) N_180;

By compensating the respective fitting residuals, a linear fit yields the second grid rotation K180 at 180 degrees.

Among them, K180 =-(K_ws_y-K_plate_y).

According to K0 and K180, the Y-axis grid rotation error K_ws_y of the substrate carrier can be obtained:

K_ws_y = (K0-K180) / 2.

It can be understood that the method of measuring the rotation error K_ws_x of the X-axis grid of the substrate stage is similar to the measurement method provided in the foregoing embodiment. Two rows (or multiple rows) of marks on the substrate in the X direction are selected for 0-degree and 180-degree measurement calibration. , As shown in Figures 9 (c) and 9 (d).

The grid error measurement method provided in this embodiment calculates the grid rotation error of the position measurement system by calculating the actual position and standard position information of the substrate adsorbed on the substrate carrier at different angles. The calculation method is simple, and The measurement position of the position measurement system is calibrated to make the final position measurement or movement position accurate, and it is not necessary to collect a large range of position data of the motion table in different attitudes (including rotation, tilt, etc.) for mathematical fitting calculations, avoiding Circumstances where multiple degrees of freedom correlation data cannot be obtained and the position model cannot be solved.

The embodiment of the present application also provides another method for measuring grid errors. FIG. 10 is a flowchart of another method for measuring grid errors according to an embodiment of the present application. Referring to FIG. 10, when the measured grid error is a non-orthogonal error, the method for measuring the grid error includes steps S310, S320, S331, S332, and S333.

In step S310, the first actual position information of the preset alignment measurement mark on the substrate is acquired through a position measurement system in the optical device, wherein the substrate is horizontally adsorbed on the substrate adsorption table of the optical device at a first angle, and the preset The alignment measurement marks include at least one row of alignment measurement marks in a first direction and at least one column of alignment measurement marks in a second direction.

It should be noted that, due to the non-orthogonal error, the displacement of the carrier linearly changes in a direction perpendicular to the carrier during the movement of the carrier in a certain direction. Exemplarily, the moving table has a linearly changing X-direction offset during the movement in the Y direction. Since there may be non-orthogonal errors in the moving table grid and the measuring base's own grid, according to 0 degrees and 90 Degree measurement results, and calculate the non-orthogonality error.

In step S320, the second actual position information of the preset alignment measurement mark is acquired by the position measurement system, wherein the substrate is horizontally adsorbed on the substrate adsorption table at a second angle, the first angle is 0 degree, and the second angle is 90 degrees.

In step S331, the first non-orthogonality error Orth_0 of the measurement grid is fitted and calculated when the substrate is adsorbed on the substrate adsorption table at a level of 0 degrees.

pos_xm_0 = Tx_0 + xm × Sx_0-ym × Rzy_0 + Res_xm_0;

pos_ym_0 = Ty_0 + ym × Sy_0 + xm × Rzx_0 + Res_ym_0;

Orth_0 = Rzy_0-Rzx_0;

Among them, pos_xm_0 is the coordinate value of the first actual position information of any of the alignment measurement marks at 0 degrees in the second direction, and pos_ym_0 is the alignment value of any of the alignment measurement marks at 0 degrees. The coordinate value of the first actual position information in the first direction, xm is the coordinate value of the standard position information of any alignment measurement mark in the second direction, and ym is the standard position information of any alignment measurement mark at The coordinate value in the first direction, Tx_0 is the translation of the entire alignment measurement mark at 0 degrees in the first direction, Ty_0 is the translation of the entire alignment measurement mark at 0 degrees in the second direction; Sx_0 is 0 degrees The zoom magnification in the first direction, Sy_0 is the zoom magnification in the second direction at 0 degrees; Rzx_0 represents the rotation around a coordinate axis parallel to the first direction at 0 degrees, and Rzy_0 represents the rotation parallel to the first direction at 0 degrees Rotation of the coordinate axis of the two directions; Res_xm_0 is the position residual of any alignment measurement mark at 0 degrees in the first direction, and Res_ym_0 is the position residual of any alignment measurement mark at 0 degrees in the second direction difference;

In step S332, the second non-orthogonality error Orth_90 of the measurement grid is fitted and calculated when the substrate is adsorbed on the substrate adsorption table at a level of 90 degrees.

pos_xm_90 = Tx_90 + xm × Sx_90-ym × Rzy_90 + Res_xm_90;

pos_ym_90 = Ty_90 + ym × Sy_90 + xm × Rzx_90 + Res_ym_90;

Orth_90 = Rzy_90-Rzx_90;

Among them, pos_xm_90 is the coordinate value of the second actual position information of any alignment measurement mark at 90 degrees in the second direction, and pos_ym_90 is the second actual position information of any alignment measurement mark at 90 degrees at the first The coordinate value in the direction, Tx_90 is the translation of the entire measurement mark in the first direction at 90 degrees, Ty_90 is the translation of the entire measurement mark in the second direction at 90 degrees; Sx_90 is the 90 ° The magnification in the first direction, Sy_90 is the magnification in the second direction at 90 degrees; Rzx_90 represents the rotation around a coordinate axis parallel to the first direction at 90 degrees, and Rzy_90 represents the rotation parallel to the second direction at 90 degrees The rotation of the coordinate axis; Res_xm_90 is the position residual of any alignment measurement mark at 90 degrees in the first direction, and Res_ym_90 is the position residual of any alignment measurement mark at 90 degrees in the second direction.

In step S333, the grid non-orthogonality error Orth_ws of the position measurement system is calculated according to the first non-orthogonality error and the second non-orthogonality error.

Orth_ws = (Orth_0 + Orth_90) / 2.

FIG. 11 is a schematic diagram of a non-orthogonality error provided by an embodiment of the present application. Referring to FIG. 11, for example, taking the first direction as the X direction and the second direction as the Y direction as an example, the grid non-orthogonality error is measured by the above grid error measurement method.

First, select one row and one column (or multiple rows and multiple columns) of alignment measurement marks as the preset alignment measurement marks. The standard position information of each preset alignment measurement mark can be recorded in advance, for example, the standard position information of Mark1 is recorded. Is (x1, y1), the standard position information of Mark2 is (x2, y2), and the standard position information of multiple different alignment measurement mark pairs recorded in sequence is (x3, y3), (x4, y4) ... (xM , YM).

Secondly, referring to FIG. 11 (a), the substrate is adsorbed on the substrate adsorption table of the optical device at a level of 0 degrees, and the first actual position information of the preset alignment measurement mark is sequentially measured. Exemplarily, the first actual position information of Mark1 is recorded as (pos_x1_0, pos_y1_0), the first actual position information of Mark2 is (pos_x2_0, pos_y2_0), and the first actual position information of multiple different alignment measurement mark pairs are sequentially recorded. Are (pos_x3_0, pos_y3_0), (pos_x4_0, pos_y4_0) ... and (pos_xM_0, pos_yM_0).

According to the obtained first actual position information and standard position information of the M preset alignment measurement marks, the first non-orthogonality error Orth_0 of the measurement grid at 0 degrees is fitted and calculated:

pos_x1_0 = Tx_0 + x1 × Sx_0-y1 × Rzy_0 + Res_x1_0;

pos_y1_0 = Ty_0 + y1 × Sy_0 + x1 × Rzx_0 + Res_y1_0;

pos_x2_0 = Tx_0 + x2 × Sx_0-y2 × Rzy_0 + Res_x2_0;

pos_y2_0 = Ty_0 + y2 × Sy_0 + x2 × Rzx_0 + Res_y2_0;

...

pos_xm_0 = Tx_0 + xm × Sx_0-ym × Rzy_0 + Res_xm_0;

pos_ym_0 = Ty_0 + ym × Sy_0 + xm × Rzx_0 + Res_ym_0;

Fit according to the above multiple formulas to obtain Rzx_0 and Rzy_0, and obtain the first non-orthogonal error Orth_0: Orth_0 = Rzy_0-Rzx_0.

Since there may be non-orthogonal errors in the grid of the moving table and the grid of the measurement base itself, the first non-orthogonal error Orth_0 obtained at 0 degrees is the superposition of the non-orthogonal errors of the two: Orth_0 = (Orth_ws + Orth_plate), Orth_ws is the grid non-orthogonality error of the motion table, and Orth_plate is the grid non-orthogonality error of the measurement base itself.

Then, referring to FIG. 11 (b), the substrate is adsorbed on the substrate adsorption table of the optical device at a 90-degree level, and the second actual position information of the preset alignment measurement mark is sequentially measured. Exemplarily, the second actual position information of Mark1 is recorded as (pos_x1_90, pos_y1_90), the second actual position information of Mark2 is (pos_x2_90, pos_y2_90), and the second actual position information of a plurality of different alignment measurement mark pairs is sequentially recorded. (Pos_x3_90, pos_y3_90), (pos_x4_90, pos_y4_90) ... (pos_xM_90, pos_yM_90).

According to the obtained M second actual position information and standard position information, fit and calculate the second non-orthogonality error Orth_90 of the measurement grid at 90 degrees:

pos_x1_90 = Tx_90 + x1 × Sx_90-y1 × Rzy_90 + Res_x1_90;

pos_y1_90 = Ty_90 + y1 × Sy_90 + x1 × Rzx_90 + Res_y1_90;

pos_x2_90 = Tx_90 + x2 × Sx_90-y2 × Rzy_90 + Res_x2_90;

pos_y2_90 = Ty_90 + y2 × Sy_90 + x2 × Rzx_90 + Res_y2_90;

...

pos_xm_90 = Tx_90 + xm × Sx_90-ym × Rzy_90 + Res_xm_90;

pos_ym_90 = Ty_90 + ym × Sy_90 + xm × Rzx_90 + Res_ym_90;

Fit according to the above multiple formulas to obtain Rzy_90 and Rzx_90, and obtain the second non-orthogonality error Orth_90: Orth_90 = Rzy_90-Rzx_90.

Calculate the grid non-orthogonality error Orth_ws of the position measurement system according to Orth_0 and Orth_90:

Orth_ws = (Orth_0 + Orth_90) / 2.

The grid error measurement method provided in this embodiment calculates the grid non-orthogonality error of the position measurement system by calculating the actual position and standard position information of the substrate adsorbed on the substrate carrier at different angles, and the calculation method is simple. The measurement position of the position measurement system can be calibrated to make the final position measurement or movement position accurate, and it is not necessary to collect a large range of position data of the motion table under different attitudes (including rotation, tilt, etc.) for mathematical fitting calculations. It avoids the situation where the correlation data of multiple degrees of freedom cannot be obtained and the position model cannot be solved.

The embodiment of the present application also provides another method for measuring grid errors. FIG. 12 is a flowchart of another method for measuring a grid error according to an embodiment of the present application. Referring to FIG. 12, when the measured grid error is a translation error, the method for measuring the grid error includes steps S410, S420, S431, S432, and S433.

In step S410, the first actual position information of the preset alignment measurement mark on the substrate is acquired through a position measurement system in the optical device, wherein the substrate is horizontally adsorbed on the substrate adsorption table of the optical device at a first angle, and the preset The alignment measurement mark includes at least one column of alignment measurement marks in the second direction.

In step S420, the second actual position information of the preset alignment measurement mark is acquired by the position measurement system, wherein the substrate is horizontally adsorbed on the substrate adsorption table at a second angle, the first angle is 0 degree, and the second angle is 180 degree.

In step S431, the first translation error Res_xp_0 of the measurement grid is calculated by fitting and calculating when the substrate is adsorbed on the substrate adsorption table at a level of 0 degrees.

pos_xp_0 = Tx_0 + xp × Sx_0-yp × Rzy_0 + Res_xp_0; where pos_xp_0 is the coordinate value of the first actual position information of any alignment measurement mark in the preset alignment measurement mark at 0 degrees in the second direction , Xp is the coordinate value of the standard position information of any alignment measurement mark in the second direction, yp is the coordinate value of the standard position information of any alignment measurement mark in the first direction, Tx_0 is at 0 degrees Align the entire measurement mark in the first direction, Sx_0 is the zoom factor in the first direction at 0 degrees, and Rzy_0 represents the rotation around a coordinate axis parallel to the second direction at 0 degrees;

In step S432, the second translation error Res_xp_180 of the measurement grid is fitted and calculated when the substrate is adsorbed on the substrate adsorption table at the 180 degree level.

pos_xp_180 = Tx_180 + xp × Sx_180-yp × Rzy_180 + Res_xp_180; where pos_xp_180 is the coordinate value of the second actual position information of any alignment measurement mark at 180 degrees in the second direction, and Tx_180 is aligned at 180 degrees Measure the translation of the marker in the first direction as a whole. Sx_180 is the magnification in the first direction at 180 degrees, and Rzy_180 represents the rotation around a coordinate axis parallel to the second direction at 180 degrees.

In step S433, the grid translation error Res_xp_ps of the position measurement system with respect to any alignment measurement mark in the first direction is calculated according to the first translation error and the second translation error.

Res_xp_ps = (Res_xp_0 + Res_xp_180) / 2.

FIG. 13 is a schematic diagram of a translation error provided by an embodiment of the present application. Referring to FIG. 13, for example, taking the first direction as the X direction and the second direction as the Y direction as an example, the X-axis grid translation error is measured by the above-mentioned grid error measurement method.

First, select one (or more) rows of alignment measurement marks as preset alignment measurement marks. As shown in Figure 13 (a), you can record the standard position information of each preset alignment measurement mark in advance, for example, record Mark1 The standard position information is (x1, y1), the standard position information of Mark2 is (x2, y2), and the standard position information of multiple different alignment measurement mark pairs is sequentially recorded as (x3, y3), (x4, y4) ... (xP, yP).

Next, referring to FIG. 13 (a), the substrate is adsorbed on the substrate adsorption table of the optical device at a level of 0 degrees, and the first actual position information of the preset alignment measurement mark is sequentially measured. Exemplarily, the first actual position information of Mark1 is recorded as (pos_x1_0, pos_y1_0), the first actual position information of Mark2 is (pos_x2_0, pos_y2_0), and the first actual position information of multiple different alignment measurement mark pairs are sequentially recorded. Are (pos_x3_0, pos_y3_0), (pos_x4_0, pos_y4_0) ... and (pos_xP_0, pos_yP_0).

According to the obtained first actual position information and standard position information of the P preset alignment measurement marks, fit and calculate the first translation error Res_xp_0 of the measurement grid at 0 degrees:

pos_x1_0 = Tx_0 + x1 × Sx_0-y1 × Rzy_0 + Res_x1_0;

pos_x2_0 = Tx_0 + x2 × Sx_0-y2 × Rzy_0 + Res_x2_0;

...

pos_xp_0 = Tx_0 + xp × Sx_0-yp × Rzy_0 + Res_xp_0;

Among them, Res_xp_0 is the position residual in the X direction, that is, the first translation residual in the X direction of the measurement grid at 0 degrees.

Since there may be grid translation errors on the moving platform and the measurement base itself, the first translation residual Res_xp_0 is the superposition of the grid translation errors of the two;

Res_xp_0 = Res_xp_ws + Res_xp_plate;

Among them, Res_xp_ps is the X translation residual of the grid of the kinematic table at the p point, and Res_xp_plate is the X translation residual of the grid itself at the p point.

Then, referring to FIG. 13 (b), the substrate is adsorbed on the substrate adsorption table of the optical device at a 180-degree level, and the second actual position information of the preset alignment measurement mark is sequentially measured. Exemplarily, the second actual position information of Mark1 is recorded as (pos_x1_180, pos_y1_180), the second actual position information of Mark2 is (pos_x2_180, pos_y2_180), and the second actual position information of multiple different alignment measurement mark pairs are recorded in sequence. It is (pos_x3_180, pos_y3_180), (pos_x4_180, pos_y4_180) ... (pos_xN_180, pos_yN_180).

According to the obtained second actual position information and standard position information of the P preset alignment measurement marks, fit and calculate the second translation error Res_xp_180 of the measurement grid at 0 degrees:

pos_x1_180 = Tx_180 + x1 × Sx_180-y1 × Rzy_180 + Res_x1_180;

pos_x2_180 = Tx_180 + x2 × Sx_180-y2 × Rzy_180 + Res_x2_180;

...

pos_xp_180 = Tx_180 + xp × Sx_180-yp × Rzy_180 + Res_xp_180;

Among them, Res_xp_180 is the position residual in the X direction, that is, the second translation residual in the X direction of the measurement grid at 180 degrees.

Among them, Res_xp_180 = Res_xp_ws-Res_xp_plate.

According to Res_xp_0 and Res_xp_180, the X-axis grid translation error of the substrate carrier can be obtained.

Res_xp_ps = (Res_xp_0 + Res_xp_180) / 2.

It can be understood that the method for measuring the Y-grid translation error of the substrate stage Y Res_yp_ps is similar to the measurement method provided in the foregoing embodiment. One column (or multiple columns) of marks on the substrate in the Y direction is selected for 0-degree and 180-degree measurement calibration, such as Figures 13 (c) and 13 (d).

The grid error measurement method provided in this embodiment calculates the grid translation error of the position measurement system by calculating the actual position and standard position information of the substrate adsorbed on the substrate carrier at different angles. The calculation method is simple, and the position can be calculated. The measurement position of the measurement system is calibrated to make the final position measurement or movement position accurate, and it is not necessary to collect a large range of position data of the motion table under different attitudes (including rotation, tilt, etc.) for mathematical fitting calculations, which prevents the A case where multiple degrees of freedom correlation data are obtained and the position model cannot be solved.

In order to measure the grid error in the position measurement system by using the grid error measurement method provided by the foregoing embodiment. An embodiment of the present application further provides a device for measuring a grid error.

FIG. 14 is a structural block diagram of a raster error measuring device according to an embodiment of the present application. As shown in FIG. 14, the raster error measurement device includes a first actual position information module 51 configured to obtain first actual position information of a preset alignment measurement mark on a substrate through a position measurement system in an optical device, The substrate is provided with a plurality of alignment measurement marks arranged in an array along the first direction and the second direction to form a measurement grid. The substrate is horizontally adsorbed on a substrate adsorption table of an optical device at a first angle. The direction is perpendicular to the second direction; the second actual position information acquisition module 52 is configured to obtain the second actual position information of a preset alignment measurement mark through a position measurement system, wherein the substrate is horizontally adsorbed on the substrate by a second angle On the stage, the second angle is different from the first angle; the grid error calculation module 53 is configured to calculate the position of the position measurement system based on the first actual position information, the second actual position information, and standard position information of a preset alignment measurement mark. Raster error.

In an embodiment, the first direction is parallel to the X axis in the preset coordinate system, and the second direction is parallel to the Y axis in the preset coordinate system; or, the first direction is parallel to the Y axis in the preset coordinate system, The second direction is parallel to the X axis in the preset coordinate system.

The grid error measuring device can measure different kinds of grid errors in the position measurement system by using the grid error measuring method in the above embodiment, and obtain a preset by adsorbing a substrate on a substrate adsorption table at different adsorption angles. Align the actual position information of the measurement marks at different adsorption angles and calculate the grid error of the position measurement system. The calculation method is simple. The measurement position of the position measurement system can be calibrated to make the final position measurement or movement position accurate. And it is not necessary to collect a large range of position data of the motion table under different attitudes (including rotation, tilt, etc.) for mathematical fitting calculations, avoiding the situation that the position model cannot be solved because correlation data of multiple degrees of freedom cannot be obtained.

In an embodiment, the preset alignment measurement mark includes at least two columns of the alignment measurement marks in the second direction, the first angle is 0 degrees, and the second angle is 180 degrees .

The grid error calculation module includes a first grid rotation degree determination unit, a second grid rotation degree determination unit, and a grid rotation degree error calculation unit.

The first grid rotation degree determining unit is configured to determine, according to the first actual position information and standard position information of a preset alignment measurement mark, a first grid of the measurement grid when the substrate is adsorbed on the substrate adsorption table at a level of 0 degrees. Grid rotation.

The second grid rotation degree determining unit is configured to determine, according to the second actual position information and standard position information of a preset alignment measurement mark, a second grid for measuring the grid when the substrate is adsorbed on the substrate adsorption platform at a 180-degree level. Grid rotation.

The grid rotation degree error calculation unit is configured to calculate a grid rotation degree error in a second direction of the position measurement system according to the first grid rotation degree and the second grid rotation degree.

In an embodiment, the first grid rotation degree determination unit includes a first rotation amount calculation sub-unit and a first grid rotation degree fitting sub-unit.

The first rotation amount calculation subunit is configured to calculate a first rotation amount of the alignment measurement mark pair according to the first actual position information and the standard position information of the alignment measurement mark pair, where the alignment measurement mark pair includes The two alignment measurement marks located in the same row in the first direction, and any of the first rotation amounts Rotyn_0 satisfies: Rotyn_0 = (pos_yj_0-pos_yi_0) / (xj-xi), and pos_yi_0 is below 0 degrees The coordinate value in the first direction of the first actual position information of the first alignment measurement mark in the alignment measurement mark pair, and pos_yj_0 is the second alignment measurement mark in the alignment measurement mark pair at 0 degrees The coordinate value of the first actual position information in the first direction, xi is the coordinate value of the standard position information of the first alignment measurement mark in the second direction, and xj is the standard position information of the second alignment measurement mark. The coordinate value in the second direction.

The first grid rotation degree fitting sub-unit is configured to calculate the first grid rotation degree according to the first rotation amount and standard position information of a plurality of different alignment measurement mark pairs, wherein the linear fitting The formula satisfies: Rotyn_0 = K0 × (yi + yj) / 2 + dRotyn_0, K0 is the first grid rotation degree, and yi is the coordinate value of the standard position information of the first alignment measurement mark in the first direction, yj is the coordinate value of the standard position information of the second alignment measurement mark in the first direction, and dRotyn_0 is the fitting residual at 0 degrees.

The second grid rotation degree determination unit includes a second rotation amount calculation sub-unit and a second grid rotation degree fitting sub-unit.

The second rotation amount calculation subunit is configured to calculate a second rotation amount of the alignment measurement mark pair according to the second actual position information and the standard position information of the alignment measurement mark pair. Any second rotation amount Rotyn_180 satisfies: Rotyn_180 = (pos_yj_180-pos_yi_180) / (-xj + xi), pos_yi_180 is the coordinate value of the first actual position information of the first alignment measurement mark in the alignment measurement mark pair at 180 degrees in the first direction Pos_yj_180 is the coordinate value of the first actual position information of the second alignment measurement mark in the alignment measurement mark pair at 180 degrees in the first direction.

The second grid rotation degree fitting subunit is configured to linearly calculate the second grid rotation degree according to the second rotation amounts and standard position information of a plurality of different alignment measurement mark pairs, where the linearity is The fitting formula satisfies: Rotyn_180 = K180 × (-yi-yj) / 2 + dRotyn_180, K180 is the second grid rotation degree, and dRotyn_180 is the fitting residual at 180 degrees.

Correspondingly, the grid rotation error K_ws_z in the second direction of the position measurement system calculated from the first grid rotation and the second grid rotation satisfies the following formula: K_ws_z = (K0-K180) / 2.

In one embodiment, the preset alignment measurement mark includes at least one row of alignment measurement marks in the first direction and at least one column of alignment measurement marks in the second direction. The first angle is 0 degrees, the first The two angles are 90 degrees.

The grid error calculation module includes a first non-orthogonality fitting unit, a second non-orthogonality fitting unit, and a grid non-orthogonality error calculating unit.

The first non-orthogonality fitting unit is configured to fit the first non-orthogonality error Orth_0 of the measurement grid when the calculation substrate is adsorbed on the substrate adsorption platform at the 0 degree level:

pos_xm_0 = Tx_0 + xm × Sx_0-ym × Rzy_0 + Res_xm_0;

pos_ym_0 = Ty_0 + ym × Sy_0 + xm × Rzx_0 + Res_ym_0;

Orth_0 = Rzy_0-Rzx_0;

Among them, pos_xm_0 is the coordinate value of the first actual position information of any of the alignment measurement marks preset at 0 degrees in the second direction, and pos_ym_0 is any alignment measurement at 0 degrees The coordinate value of the first actual position information of the marker in the first direction, xm is the coordinate value of the standard position information of any alignment measurement mark in the second direction, and ym is the standard position of any alignment measurement mark. The coordinate value of the information in the first direction, Tx_0 is the translation of the entire measurement mark in the first direction at 0 degrees, and Ty_0 is the translation of the entire measurement mark in the second direction at 0 degrees; Sx_0 is Magnification in the first direction at 0 degrees, Sy_0 is the magnification in the second direction at 0 degrees; Rzx_0 represents rotation around a coordinate axis parallel to the first direction at 0 degrees, and Rzy_0 represents parallel rotation at 0 degrees Rotation of the coordinate axis in the second direction; Res_xm_0 is the position residual of any alignment measurement mark at 0 degrees in the first direction, and Res_ym_0 is the alignment error of any alignment measurement mark at 0 degrees in the second direction Location residuals.

The second non-orthogonal fitting unit is set to fit the second non-orthogonality error Orth_90 of the measurement grid when the substrate is adsorbed on the substrate adsorption platform at a 90 degree level:

pos_xm_90 = Tx_90 + xm × Sx_90-ym × Rzy_90 + Res_xm_90;

pos_ym_90 = Ty_90 + ym × Sy_90 + xm × Rzx_90 + Res_ym_90;

Orth_90 = Rzy_90-Rzx_90;

Among them, pos_xm_90 is the coordinate value of the second actual position information of any alignment measurement mark at 90 degrees in the second direction, and pos_ym_90 is the second actual position information of any alignment measurement mark at 90 degrees at the first The coordinate value in the direction, Tx_90 is the translation of the entire measurement mark at 90 degrees in the first direction, Ty_90 is the translation of the entire measurement mark at 90 degrees in the second direction; Sx_90 is 90 degrees The zoom ratio in the first direction, Sy_90 is the zoom ratio in the second direction at 90 degrees; Rzx_90 represents the rotation around a coordinate axis parallel to the first direction at 90 degrees, and Rzy_90 represents the rotation parallel to the first direction at 90 degrees Rotation of coordinate axes in two directions; Res_xm_90 is the residual position of any alignment measurement mark at 90 degrees in the first direction, and Res_ym_90 is the residual position of any alignment measurement mark at 90 degrees in the second direction difference.

The grid non-orthogonality error calculation unit is configured to calculate the grid non-orthogonality error Orth_ws of the position measurement system according to the first non-orthogonality and the second non-orthogonality: Orth_ws = (Orth_0 + Orth_90) / 2.

In one embodiment, the preset alignment measurement mark includes at least one column of alignment measurement marks in the second direction, the first angle is 0 degrees, and the second angle is 180 degrees.

The grid error calculation module includes a first translation error fitting unit, a second translation error fitting unit, and a grid translation error calculation unit.

The first translation error fitting unit is configured to fit and calculate the first translation error Res_xp_0 of the measurement grid when the substrate is adsorbed on the substrate adsorption platform at a level of 0 degrees:

pos_xp_0 = Tx_0 + xp × Sx_0-yp × Rzy_0 + Res_xp_0; where pos_xp_0 is the coordinate value of the first actual position information of any alignment measurement mark in the preset alignment measurement mark at 0 degrees in the second direction , Xp is the coordinate value of the standard position information of any alignment measurement mark in the second direction, yp is the coordinate value of the standard position information of any alignment measurement mark in the first direction, Tx_0 is at 0 degrees The translation of the alignment measurement mark as a whole in the first direction, Sx_0 is the zoom factor in the first direction at 0 degrees, and Rzy_0 represents the rotation around a coordinate axis parallel to the second direction at 0 degrees.

The second translation error fitting unit is configured to fit and calculate the second translation error Res_xp_180 of the measurement grid when the substrate is adsorbed on the substrate adsorption platform at a 180-degree level:

The grid translation error calculation unit is configured to calculate the grid translation error Res_xp_ps of the first direction of the position measurement system relative to any alignment measurement mark according to the first translation error and the second translation error:

Res_xp_ps = (Res_xp_0 + Res_xp_180) / 2.

An embodiment of the present application further provides an optical device, and the optical device includes a grid error measuring device provided by any of the foregoing embodiments.

In one embodiment, the optical device includes a lithography machine.

The optical device provided in this embodiment calculates the grid error of the position measurement system by calculating the actual position and standard position information of the substrate adsorbed on the substrate stage at different angles. The calculation method is simple, and the measurement position of the position measurement system can be measured. Perform calibration to make the final position measurement or movement position accurate, and do not need to collect a large range of position data of the motion table under different attitudes (including rotation, tilt, etc.) for mathematical fitting calculations, avoiding the inability to obtain multiple degrees of freedom The situation that the position model cannot be solved.

Claims

A method for measuring grid errors, including:

The first actual position information of a preset alignment measurement mark on a substrate is obtained through a position measurement system in an optical device, wherein the substrate is provided with a plurality of alignments arranged in an array along a first direction and a second direction. Measuring the marks to form a measurement grid, the substrate is horizontally adsorbed on a substrate adsorption table of the optical device at a first angle, and the first direction is perpendicular to the second direction;

The second actual position information of the preset alignment measurement mark is obtained through the position measurement system, wherein the substrate is horizontally adsorbed on the substrate adsorption table at a second angle, and the second angle is different from that Mentioned first angle

Calculate a grid error of the position measurement system according to the first actual position information, the second actual position information, and standard position information of the preset alignment measurement mark.
The method for measuring a grid error according to claim 1, wherein the first direction is parallel to an X axis in a preset coordinate system, and the second direction is parallel to a Y axis in the preset coordinate system; Alternatively, the first direction is parallel to the Y axis in the preset coordinate system, and the second direction is parallel to the X axis in the preset coordinate system.
The method for measuring a grid error according to claim 2, wherein the preset alignment measurement mark includes at least two columns of the alignment measurement marks in the second direction, and the first angle 0 degrees, and the second angle is 180 degrees;

Calculating a grid error of the position measurement system according to the first actual position information, the second actual position information, and standard position information of the preset alignment measurement mark includes:

Determining, according to the first actual position information and the standard position information of the preset alignment measurement mark, a first grid of a measurement grid when the substrate is adsorbed on the substrate adsorption table at the 0 degree level Degree of rotation

Determining a second grid of a measurement grid when the substrate is adsorbed on the substrate adsorption table at the 180-degree level according to the second actual position information and standard position information of the preset alignment measurement mark Degree of rotation

A grid rotation error in the second direction of the position measurement system is calculated according to the first grid rotation and the second grid rotation.
The method for measuring a grid error according to claim 3, wherein, according to the first actual position information and standard position information of the preset alignment measurement mark, determining that the substrate is adsorbed at the 0 degree level Measuring the first grid rotation of the grid when the base is adsorbed on the table includes:

Calculating a first rotation amount of the alignment measurement mark pair according to the first actual position information and the standard position information of the alignment measurement mark pair, wherein the alignment measurement mark pair is included in the first party Two of the alignment measurement marks located in the same row upward, any one of the first rotation amounts Rotyn_0 satisfies: Rotyn_0 = (pos_yj_0-pos_yi_0) / (xj-xi), pos_yi_0 is the alignment at 0 degrees The coordinate value of the first actual position information of the first alignment measurement mark in the measurement mark pair in the first direction, and pos_yi_0 is a second alignment measurement mark in the alignment measurement mark pair at 0 degrees. The coordinate value of the first actual position information in the first direction, xi is the coordinate value of the standard position information of the first alignment measurement mark in the second direction, and xj is the second pair A coordinate value of the standard position information of the quasi-measurement mark in the second direction;

According to the first rotation amount and standard position information of a plurality of different alignment measurement mark pairs, the first grid rotation degree is calculated by linear fitting, wherein the linear fitting formula satisfies: Rotyn_0 = K0 × (yi + yj ) / 2 + dRotyn_0, K0 is the rotation degree of the first grid, yi is the coordinate value of the standard position information of the first alignment measurement mark in the first direction, and yj is the second pair A coordinate value of the standard position information of the quasi-measurement mark in the first direction, and dRotyn_0 is a fitting residual at 0 degrees;

Determining a second grid of a measurement grid when the substrate is adsorbed on the substrate adsorption table at the 180-degree level according to the second actual position information and standard position information of the preset alignment measurement mark Rotation, including:

Calculate a second rotation amount of the alignment measurement mark pair according to the second actual position information and the standard position information of the alignment measurement mark pair. Any of the second rotation amounts Rotyn_180 satisfies: Rotyn_180 = (pos_yj_180 -pos_yi_180) / (-xj + xi), pos_yi_180 is the coordinate value in the first direction of the first actual position information of the first alignment measurement mark in the alignment measurement mark pair at 180 degrees, pos_yj_180 A coordinate value of the first actual position information of a second alignment measurement mark in the alignment measurement mark pair at 180 degrees in the first direction;

According to the second rotation amount and standard position information of a plurality of different alignment measurement mark pairs, the second grid rotation degree is calculated by linear fitting, wherein the linear fitting formula satisfies: Rotyn_180 = K180 × (-yi- yj) / 2 + dRotyn_180, K180 is the second grid rotation degree, and dRotyn_180 is the fitting residual at 180 degrees;

The grid rotation error K_ws_z of the second direction of the position measurement system calculated according to the first grid rotation and the second grid rotation satisfies the following formula:

K_ws_z = (K0-K180) / 2.
The method for measuring a grid error according to claim 2, wherein the preset alignment measurement mark includes at least one row of the alignment measurement mark in the first direction and the alignment measurement mark in the second direction The at least one column of the alignment measurement marks, the first angle is 0 degrees, and the second angle is 90 degrees;

Calculating a grid error of the position measurement system according to the first actual position information, the second actual position information, and standard position information of the preset alignment measurement mark includes:

The first non-orthogonality error Orth_0 of the measurement grid when the substrate is adsorbed on the substrate adsorption platform at the 0 degree level is calculated by fitting:

pos_xm_0 = Tx_0 + xm × Sx_0-ym × Rzy_0 + Res_xm_0;

pos_ym_0 = Ty_0 + ym × Sy_0 + xm × Rzx_0 + Res_ym_0;

Orth_0 = Rzy_0-Rzx_0;

Wherein, pos_xm_0 is a coordinate value of the first actual position information of any of the preset alignment measurement marks at 0 degrees in the second direction, and pos_ym_0 is any of the values at 0 degrees. The coordinate value of the first actual position information of the alignment measurement mark in the first direction, xm is the coordinate value of the standard position information of any of the alignment measurement marks in the second direction, and ym is The coordinate value of the standard position information of any alignment measurement mark in the first direction, Tx_0 is a translation of the entire alignment measurement mark in the first direction at 0 degrees, and Ty_0 is 0 The translation of the alignment measurement mark as a whole in the second direction; Sx_0 is a zoom ratio in the first direction at 0 degrees, and Sy_0 is a zoom in the second direction at 0 degrees Magnification; Rzx_0 represents rotation around a coordinate axis parallel to the first direction at 0 degrees, Rzy_0 represents rotation around a coordinate axis parallel to the second direction at 0 degrees; Res_xm_0 is any pair described at 0 degrees The position residual of the mark in the first direction is quasi-measured, and Res_ym_0 is any of the alignment amounts at 0 degrees Mark in the second direction, position residuals;

The second non-orthogonality error Orth_90 of the measurement grid when the substrate is adsorbed on the substrate adsorption platform at the 90 degree level is calculated by fitting:

pos_xm_90 = Tx_90 + xm × Sx_90-ym × Rzy_90 + Res_xm_90;

pos_ym_90 = Ty_90 + ym × Sy_90 + xm × Rzx_90 + Res_ym_90;

Orth_90 = Rzy_90-Rzx_90;

Wherein, pos_xm_90 is the coordinate value of the second actual position information of any of the alignment measurement marks at 90 degrees in the second direction, and pos_ym_90 is the second of the any of the alignment measurement marks at 90 degrees. The coordinate value of the actual position information in the first direction, Tx_90 is the translation of the entire alignment measurement mark in the first direction at 90 degrees, and Ty_90 is the entire alignment measurement mark at 90 degrees. Translation in the second direction; Sx_90 is the zoom magnification in the first direction at 90 degrees, Sy_90 is the zoom magnification in the second direction at 90 degrees; Rzx_90 represents a parallel parallel at 90 degrees For the rotation of the coordinate axis in the first direction, Rzy_90 represents a rotation about a coordinate axis parallel to the second direction at 90 degrees; Res_xm_90 is 90 degrees at any one of the alignment measurement marks on the first side Upward position residual, Res_ym_90 is a position residual of the alignment measurement mark in the second direction at 90 degrees;

Calculate the grid non-orthogonality error Orth_ws of the position measurement system according to the first non-orthogonality error and the second non-orthogonality error:

Orth_ws = (Orth_0 + Orth_90) / 2.
The method for measuring a grid error according to claim 2, wherein the preset alignment measurement mark includes at least one column of the alignment measurement marks in the second direction, and the first angle is 0 degrees, the second angle is 180 degrees;

Calculating a grid error of the position measurement system according to the first actual position information, the second actual position information, and standard position information of the preset alignment measurement mark includes:

The first translation error of the measurement grid Res_xp_0: pos_xp_0 = Tx_0 + xp × Sx_0-yp × Rzy_0 + Res_xp_0; 0 The coordinate value of the first actual position information of any of the preset alignment measurement marks in the second direction, and xp is a standard position of any of the alignment measurement marks. The coordinate value of the information in the second direction, yp is the coordinate value of the standard position information of any of the alignment measurement marks in the first direction, and Tx_0 is the alignment measurement mark at 0 degrees The translation of the whole in the first direction, Sx_0 is a zoom factor in the first direction at 0 degrees, and Rzy_0 represents a rotation around a coordinate axis parallel to the second direction at 0 degrees;

The second translation error Res_xp_180 of the measurement grid when the substrate is adsorbed on the substrate adsorption platform at the 180-degree level is calculated by fitting:

pos_xp_180 = Tx_180 + xp × Sx_180-yp × Rzy_180 + Res_xp_180; where pos_xp_180 is the coordinate value of the second actual position information of the alignment measurement mark at 180 degrees in the second direction and Tx_180 is 180 The translation of the alignment measurement mark as a whole in the first direction at a degree of degree, Sx_180 is a magnification ratio in the first direction at 180 degree, and Rzy_180 represents a direction parallel to the second direction at 180 degree Rotation of the coordinate axis;

Calculate the grid translation error Res_xp_ps of the first direction of the position measurement system with respect to the alignment measurement mark according to the first translation error and the second translation error:

Res_xp_ps = (Res_xp_0 + Res_xp_180) / 2.
The method for measuring a grid error according to any one of claims 1 to 6, wherein the pattern of the alignment measurement mark is a center-symmetrical pattern.
The method for measuring a grid error according to any one of claims 1 to 6, wherein the position measurement system is an interferometer measurement system, a laser triangle, or a laser displacement sensor.
A grid error measuring device includes:

The first actual position information module is configured to obtain first actual position information of a preset alignment measurement mark on a substrate through a position measurement system in an optical device, wherein the substrate is provided with a plurality of Alignment measurement marks arranged in two directions in an array form a measurement grid. The substrate is horizontally adsorbed on a substrate adsorption table of the optical device at a first angle, and the first direction and the second direction are in phase with each other. vertical;

The second actual position information acquisition module is configured to obtain the second actual position information of the preset alignment measurement mark through the position measurement system, wherein the substrate is horizontally adsorbed on the substrate adsorption table at a second angle. The second angle is different from the first angle;

The grid error calculation module is configured to calculate a grid error of the position measurement system according to the first actual position information, the second actual position information, and standard position information of the preset alignment measurement mark.
The apparatus for measuring a grid error according to claim 9, wherein the first direction is parallel to an X axis in a preset coordinate system, and the second direction is parallel to a Y axis in the preset coordinate system; Alternatively, the first direction is parallel to the Y axis in the preset coordinate system, and the second direction is parallel to the X axis in the preset coordinate system.
The apparatus for measuring a grid error according to claim 10, wherein the preset alignment measurement mark includes at least two columns of the alignment measurement marks in the second direction, and the first angle 0 degrees, and the second angle is 180 degrees;

The grid error calculation module includes:

A first grid rotation determining unit, configured to determine that the substrate is adsorbed on the substrate at the 0 degree level according to the first actual position information and standard position information of the preset alignment measurement mark Measure the first grid rotation of the grid when on the stage;

A second grid rotation determining unit is configured to determine that the substrate is adsorbed on the substrate at the 180-degree level according to the second actual position information and standard position information of the preset alignment measurement mark. Measuring the second grid rotation of the grid when on the stage;

The grid rotation degree error calculation unit is configured to calculate a grid rotation degree error in the second direction of the position measurement system according to the first grid rotation degree and the second grid rotation degree.
The apparatus for measuring a grid error according to claim 11, wherein the first grid rotation determining unit comprises:

A first rotation amount calculation subunit configured to calculate a first rotation amount of the alignment measurement mark pair according to the first actual position information and the standard position information of the alignment measurement mark pair, wherein the alignment amount The measurement mark pair includes two of the alignment measurement marks located in the same row in the first direction, and any of the first rotation amounts Rotyn_0 satisfies: Rotyn_0 = (pos_yj_0-pos_yi_0) / (xj-xi) , Pos_yi_0 is the coordinate value of the first actual position information of the first alignment measurement mark in the alignment measurement mark pair at 0 degrees in the first direction, and pos_yj_0 is the alignment measurement at 0 degrees The coordinate value of the first actual position information of the second alignment measurement mark in the mark pair in the first direction, and xi is a standard position information of the first alignment measurement mark in the second direction. A coordinate value, xj is a coordinate value of the standard position information of the second alignment measurement mark in the second direction;

The first grid rotation degree fitting subunit is configured to linearly calculate the first grid rotation degree according to the first rotation amounts and standard position information of a plurality of different alignment measurement mark pairs, where the linearity is The fitting formula satisfies: Rotyn_0 = K0 × (yi + yj) / 2 + dRotyn_0, K0 is the rotation degree of the first grid, and yi is the standard position information of the first alignment measurement mark in the first The coordinate value in the direction, yj is the coordinate value of the standard position information of the second alignment measurement mark in the first direction, and dRotyn_0 is the fitting residual at 0 degrees;

The second grid rotation degree determining unit includes:

The second rotation amount calculation subunit is configured to calculate a second rotation amount of the alignment measurement mark pair according to the second actual position information and the standard position information of the alignment measurement mark pair. The two rotation amounts Rotyn_180 satisfy: Rotyn_180 = (pos_yj_180-pos_yi_180) / (-xj + xi), where pos_yi_180 is 180 degrees, the first actual position information of the first alignment measurement mark in the alignment measurement mark pair is Said the coordinate value in the first direction, pos_yj_180 is the coordinate value of the first actual position information of the second alignment measurement mark in the alignment measurement mark pair at 180 degrees in the first direction;

The second grid rotation degree fitting subunit is configured to linearly calculate the second grid rotation degree according to the second rotation amounts and standard position information of a plurality of different alignment measurement mark pairs, where the linearity is The fitting formula satisfies: Rotyn_180 = K180 × (-yi-yj) / 2 + dRotyn_180, K180 is the second grid rotation degree, and dRotyn_180 is the fitting residual at 180 degrees;

The grid rotation error K_ws_z of the second direction of the position measurement system calculated according to the first grid rotation and the second grid rotation satisfies the following formula:

K_ws_z = (K0-K180) / 2.
The apparatus for measuring a grid error according to claim 10, wherein the preset alignment measurement mark includes at least one row of the alignment measurement mark in the first direction and in the second direction The at least one column of the alignment measurement marks, the first angle is 0 degrees, and the second angle is 90 degrees;

The grid error calculation module includes:

A first non-orthogonality fitting unit, configured to fit and calculate a first non-orthogonality error Orth_0 of the measurement grid when the substrate is adsorbed on the substrate adsorption stage at the 0 degree level:

pos_xm_0 = Tx_0 + xm × Sx_0-ym × Rzy_0 + Res_xm_0;

pos_ym_0 = Ty_0 + ym × Sy_0 + xm × Rzx_0 + Res_ym_0;

Orth_0 = Rzy_0-Rzx_0;

Wherein, pos_xm_0 is a coordinate value of the first actual position information of any of the preset alignment measurement marks at 0 degrees in the second direction, and pos_ym_0 is any of the values at 0 degrees. The coordinate value of the first actual position information of the alignment measurement mark in the first direction, xm is the coordinate value of the standard position information of any of the alignment measurement marks in the second direction, and ym is The coordinate value of the standard position information of any alignment measurement mark in the first direction, Tx_0 is a translation of the entire alignment measurement mark in the first direction at 0 degrees, and Ty_0 is 0 The translation of the alignment measurement mark as a whole in the second direction; Sx_0 is a zoom ratio in the first direction at 0 degrees, and Sy_0 is a zoom in the second direction at 0 degrees Magnification; Rzx_0 represents rotation around a coordinate axis parallel to the first direction at 0 degrees, Rzy_0 represents rotation around a coordinate axis parallel to the second direction at 0 degrees; Res_xm_0 is any pair described at 0 degrees The position residual of the mark in the first direction is quasi-measured, and Res_ym_0 is any of the alignment amounts at 0 degrees Mark in the second direction, position residuals;

The second non-orthogonality fitting unit is configured to fit and calculate a second non-orthogonality error Orth_90 of the measurement grid when the substrate is adsorbed on the substrate adsorption platform at the 90 degree level:

pos_xm_90 = Tx_90 + xm × Sx_90-ym × Rzy_90 + Res_xm_90;

pos_ym_90 = Ty_90 + ym × Sy_90 + xm × Rzx_90 + Res_ym_90;

Orth_90 = Rzy_90-Rzx_90;

Wherein, pos_xm_90 is the coordinate value of the second actual position information of any of the alignment measurement marks at 90 degrees in the second direction, and pos_ym_90 is the second of the any of the alignment measurement marks at 90 degrees. The coordinate value of the actual position information in the first direction, Tx_90 is the translation of the entire alignment measurement mark in the first direction at 90 degrees, and Ty_90 is the entire alignment measurement mark at 90 degrees. Translation in the second direction; Sx_90 is the zoom magnification in the first direction at 90 degrees, Sy_90 is the zoom magnification in the second direction at 90 degrees; Rzx_90 represents a parallel parallel at 90 degrees For the rotation of the coordinate axis in the first direction, Rzy_90 represents a rotation about a coordinate axis parallel to the second direction at 90 degrees; Res_xm_90 is 90 degrees at any one of the alignment measurement marks on the first side Upward position residual, Res_ym_90 is a position residual of the alignment measurement mark in the second direction at 90 degrees;

The grid non-orthogonality error calculation unit is configured to calculate the grid non-orthogonality error Orth_ws of the position measurement system according to the first non-orthogonality error and the second non-orthogonality error:

Orth_ws = (Orth_0 + Orth_90) / 2.
The apparatus for measuring a grid error according to claim 10, wherein the preset alignment measurement mark includes at least one column of the alignment measurement marks in the second direction, and the first angle is 0 degrees, the second angle is 180 degrees;

The grid error calculation module includes:

The first translation error fitting unit is configured to fit and calculate a first translation error Res_xp_0 of the measurement grid when the substrate is adsorbed on the substrate adsorption platform at the 0 degree level:

pos_xp_0 = Tx_0 + xp × Sx_0-yp × Rzy_0 + Res_xp_0; wherein pos_xp_0 is the first actual position information of any alignment measurement mark in the preset alignment measurement mark at 0 degrees in the second direction Xp is the coordinate value of the standard position information of any one alignment measurement mark in the second direction, and yp is the standard position information of any one of the alignment measurement marks in the first direction. Coordinates in one direction, Tx_0 is the translation of the alignment measurement mark in the first direction at 0 degrees, Sx_0 is the zoom factor in the first direction at 0 degrees, and Rzy_0Rzy_0 represents 0 degrees Rotation around a coordinate axis parallel to the second direction;

The second translation error fitting unit is configured to fit and calculate a second translation error Res_xp_180 of the measurement grid when the substrate is adsorbed on the substrate adsorption table at the 180 degree level:

pos_xp_180 = Tx_180 + xp × Sx_180-yp × Rzy_180 + Res_xp_180; where pos_xp_180 is the coordinate value of the second actual position information of the alignment measurement mark at 180 degrees in the second direction, and Tx_180 is 180 The translation of the alignment measurement mark as a whole in the first direction at a degree of degree, Sx_180 is a magnification ratio in the first direction at 180 degree, and Rzy_180 represents a direction parallel to the second direction at 180 degree. Rotation of the coordinate axis;

A grid translation error calculating unit, configured to calculate, according to the first translation error and the second translation error, a grid translation of the position measurement system with respect to the first direction of the alignment measurement mark in the first direction; Error Res_xp_ps:

Res_xp_ps = (Res_xp_0 + Res_xp_180) / 2.
An optical device comprising the grid error measuring device according to any one of claims 9-14.
The optical apparatus according to claim 15, said optical apparatus comprising a lithography machine.