Machine applied to lithography process and machine zero searching method applied to lithography process

Abstract

The invention relates to the technical field of wafer lithography, in particular to a machine table applied to a lithography process and a machine table zero searching method applied to the lithography process, and the machine table comprises a wafer workpiece table and a measurement bit grating plane; reading heads are arranged on at least three corners of the wafer workpiece table; the measuring bit grating plane comprises a phase difference grating and a plurality of groups of zero position gratings; each reading head corresponds to one group of zero position gratings, and the zero position gratings correspond to a preset zero position of the wafer workpiece table; the zero position gratings are inclined gratings, and each group of zero position gratings comprises a plurality of parallel zero position grating lines; the line width of the zero grating line is different from the line width of the grating line of the phase difference grating. According to the invention, a zero searching assembly does not need to be added independently, and a new zero searching function is added to the original read head assembly by adding the new zero grating on the measuring bit grating plane, so that the equipment system is greatly simplified, the stability of the equipment system is improved, and the service life of the equipment is prolonged.

Description

Technical Field

[0001] The present invention relates to the field of wafer lithography, and particularly to a machine platform applied to a lithography process and a zero-searching method for a machine platform applied to a lithography process. Background Art

[0002] In the current photolithography process (or called lithography process), the machine platform usually uses a grating and a workpiece stage read head to determine the position of the wafer workpiece stage. However, since the grating and the read head are relative measurements, it is necessary to first determine the zero position of the wafer workpiece stage. This process of determining the zero position of the wafer workpiece stage is generally called "zero searching".

[0003] And the current zero-searching process requires additional hardware to implement. The above zero-searching hardware includes a laser emitter, a corner cube mirror, and a PSD (photoelectric position sensor of the surface resistance of a photodiode). The corner cube mirror is installed at the corner of the wafer workpiece stage, and the laser emitter and the PSD are arranged above the wafer workpiece stage. When the wafer workpiece stage is exactly at the zero position, the laser emitted by the laser emitter is just reflected by the corner cube mirror into the PSD. When all the PSDs receive the reflected laser, it means that the zero searching of the wafer workpiece stage has been completed. It is not difficult to see that this zero-searching method involves a wide variety of devices and occupies a large space, greatly increasing the system complexity. At the same time, the temperature drift and poor stability of the PSD result in a decrease in the working stability of the equipment and a short service life.

[0004] Therefore, how to simplify the zero-searching system, reduce the system complexity, improve the working stability of the system, and extend the service life of the equipment is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of the present invention is to provide a machine platform applied to a lithography process and a zero-searching method for a machine platform applied to a lithography process to solve the problems of high complexity, poor stability, and short service life of the zero-searching system in the prior art.

[0006] To solve the above technical problems, the present invention provides a machine platform applied to a lithography process, including a wafer workpiece stage and a measurement position grating plane;

[0007] At least three corners of the wafer workpiece stage are provided with read heads;

[0008] The measurement position grating plane includes a phase difference grating and multiple groups of zero position gratings;

[0009] Each read head corresponds to a group of the zero position gratings, and the zero position gratings correspond to the preset zero position of the wafer workpiece stage;

[0010] The zero - position grating is an inclined grating, and each group of the zero - position gratings includes a plurality of parallel zero - position grating lines; the line width of the zero - position grating lines is different from the line width of the grating lines of the phase - difference grating.

[0011] Optionally, in the machine tool applied to the lithography process, one of the zero - position grating lines is parallel to one of the grating lines of the phase - difference grating.

[0012] Optionally, in the machine tool applied to the lithography process, all the zero - position grating lines are parallel to each other.

[0013] Optionally, in the machine tool applied to the lithography process, the inclination angle of the zero - position grating is 45 degrees.

[0014] Optionally, in the machine tool applied to the lithography process, the line width of the zero - position grating lines is greater than the line width of the grating lines of the phase - difference grating.

[0015] Optionally, in the machine tool applied to the lithography process, the pitch between adjacent zero - position grating lines in the zero - position grating is not greater than 2048 nanometers.

[0016] Optionally, in the machine tool applied to the lithography process, the read head is a two - dimensional read head.

[0017] Optionally, in the machine tool applied to the lithography process, the read heads are arranged at the four corners of the wafer stage.

[0018] Optionally, in the machine tool applied to the lithography process, the measurement - position grating plane includes a zero - return area;

[0019] The zero - position grating is arranged within the zero - return area, and the phase - difference grating is arranged outside the zero - return area.

[0020] A zero - search method for a machine tool applied to the lithography process, characterized in that the zero - search method for a machine tool applied to the lithography process is implemented by the machine tool applied to the lithography process as described in any one of the above, and includes:

[0021] Perform a preliminary positioning of the wafer stage to place the wafer stage within a preset area to be calibrated;

[0022] Adjust the position of the wafer stage step - by - step until at least three read heads of the wafer stage can capture the zero - position grating;

[0023] Obtain the attitude reading value from the read head that captures the zero - position grating;

[0024] Determine the zero - position mark information according to the attitude reading value;

[0025] Adjust the wafer stage to the zero position according to the zero position marking information.

[0026] The machine tool applied to the lithography process provided by the present invention includes a wafer stage and a measurement position grating plane; at least three corners of the wafer stage are provided with readers; the measurement position grating plane includes a phase difference grating and multiple groups of zero position gratings; each reader corresponds to a group of the zero position gratings, and the zero position gratings correspond to the preset zero position of the wafer stage; the zero position gratings are inclined gratings, and each group of the zero position gratings includes multiple parallel zero position grating lines; the line width of the zero position grating lines is different from the line width of the grating lines of the phase difference grating.

[0027] In the present invention, the zero position gratings are added in the measurement position grating plane. Since the line width of the zero position gratings is different from that of the phase difference grating, they can be recognized by the readers and used as the basis for determining the wafer stage. The present invention does not need to separately add a zero search component, but adds new zero position gratings on the measurement position grating plane, adding a new zero search function to the original reader component, greatly simplifying the equipment system, improving the stability of the equipment system at the same time, and prolonging the service life of the equipment. The present invention also provides a zero search method for the machine tool applied to the lithography process with the above beneficial effects. Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0029] Figure 1 It is a schematic structural diagram of a specific embodiment of the machine tool applied to the lithography process provided by the present invention;

[0030] Figure 2 It is a partial structural diagram of a specific embodiment of the machine tool applied to the lithography process provided by the present invention;

[0031] Figure 3 It is a partial structural diagram of another specific embodiment of the machine tool applied to the lithography process provided by the present invention;

[0032] Figure 4 It is a schematic flow diagram of a specific embodiment of the zero search method for the machine tool applied to the lithography process provided by the present invention;

[0033] Figure 5 It is a schematic structural diagram of a specific embodiment of the zero search device for the machine tool applied to the lithography process provided by the present invention.

[0034] In the figure, it includes a 10-wafer workpiece stage, an 11-reader head, a 20-measurement position grating plane, a 21-zero position grating, a 22-phase difference grating, and a 30-area to be calibrated. Specific implementation manner

[0035] In order to enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0036] The core of the present invention is to provide a machine tool applied to the lithography process. The structural schematic diagram of a specific implementation manner is as Figure 1 shown, which is called the first specific implementation manner, and includes a wafer workpiece stage 10 and a measurement position grating plane 20;

[0037] At least three corners of the wafer workpiece stage 10 are provided with reader heads 11;

[0038] The measurement position grating plane 20 includes a phase difference grating 22 and multiple groups of zero position gratings 21;

[0039] Each reader head 11 corresponds to a group of zero position gratings 21, and the zero position grating 21 corresponds to the preset zero position of the wafer workpiece stage 10;

[0040] The zero position grating 21 is an inclined grating, and each group of zero position gratings 21 includes multiple parallel zero position grating lines; the line width of the zero position grating lines is different from the line width of the grating lines of the phase difference grating 22.

[0041] The zero position grating line refers to a single linear structure in the zero position grating 21.

[0042] The phase difference grating 22 is a reticular grating that is inclined and staggered in two directions and intersects each other, and is used to measure the relative displacement of the wafer workpiece stage 10. For details, please see Figure 2 , Figure 2 is the structural schematic diagram within the measurement grating plane of the machine tool applied to the lithography process.

[0043] As a preferred embodiment, the zero - position grating lines are parallel to one of the grating lines in the phase - difference grating 22. As mentioned before, the phase - difference grating 22 is used to measure the relative displacement of the wafer stage 10, and the inclination directions of the zero - position grating lines are the same as the two inclination directions of the phase - difference grating 22. Thus, the program used to measure the relative displacement of the wafer stage 10 can be slightly modified to be used for judging the position of the zero - position grating 21, greatly reducing the computing power requirement and the program design difficulty, and improving the operation efficiency.

[0044] Let the directions of the grating lines in the phase - difference grating 22 be the first direction and the second direction respectively. Different groups of zero - position gratings 21 can all extend along the first direction or the second direction, or some groups of zero - position gratings 21 can extend along the first direction and the other part can extend along the second direction.

[0045] Furthermore, all the zero - position grating lines are parallel to each other. All the zero - position grating lines extend along the same direction, which can further reduce the computing power requirement, simplify the program, and at the same time greatly reduce the production difficulty of the equipment.

[0046] Furthermore, the inclination angle of the zero - position grating 21 is 45 degrees. When the inclination angle of the zero - position grating 21 is 45 degrees, the components of the grating lines in the X - direction and the Y - direction are the same, greatly reducing the calculation pressure, reducing the computing power consumption, and improving the calculation efficiency.

[0047] In addition, the line width of the zero - position grating lines is greater than the line width of the grating lines in the phase - difference grating 22. The width of the zero - position grating lines is larger than the line width of the grating lines in the phase - difference grating 22, which can improve the recognition accuracy of the zero - position grating 21, and further improve the positioning accuracy of zero - search.

[0048] Also, the pitch between adjacent zero - position grating lines in the zero - position grating 21 is not greater than 2048 nanometers.

[0049] Generally, in an immersion machine tool, the position formula of the wafer stage 10 in the plane is shown as the following formula (1):

[0050]

[0051] Where x is the grating displacement measured in the plane, a1 and a2 are the phase changes of the two - path measurement interference signals relative to the reference interference signal, and P is the grating pitch of the measurement grating.

[0052] It can be known from Equation (1) that it is directly related to the grating pitch P in the horizontal direction (X, Y directions) and the grating to be measured (which can be the zero-position grating 21 or the phase-difference grating 22). To improve the measurement accuracy, the size of the grating pitch P can be reduced. Currently, the mainstream machine tools use a grating pitch of 2048 nanometers, and it can also be reduced to a grating pitch of 1024 nanometers to improve the measurement accuracy to several hundred nanometers. x in the above Equation (1) can also be replaced by y, both being directions in the plane, so there is no difference.

[0053] In addition, the position formula of the wafer stage 10 in the Z direction is shown in the following Equation (2):

[0054]

[0055] Among them, z is the grating displacement perpendicular to the plane, λ is the laser wavelength of the read head 11, and θ is the Littrow angle. The accuracy in the vertical direction (Z direction) is related to the laser wavelength of the read head 11.

[0056] As a preferred implementation, the read head 11 is a two-dimensional read head 11. The two-dimensional read head 11 is a read head 11 including two sensors. There are at most four two-dimensional read heads 11 at the four corners of the wafer stage 10 (usually three are set at three corners). At this time, 8 groups of data can be measured (if only three corners are set, 6 groups of data can be measured), so that the 6 degrees of freedom of the wafer stage 10 can be obtained (3 translational degrees of freedom: X, Y, Z, and 3 rotational degrees of freedom: Rx, Ry, Rz).

[0057] Preferably, the read head 11 is provided at the four corners of the wafer stage 10. The wafer stage 10 is usually rectangular, that is, it has four corners. As a specific implementation, there can be one read head 11 at each of the four corners, which can greatly improve the applicability and working stability of the stage, as Figure 1 shown.

[0058] The machine tool applied to the lithography process provided by the present invention includes a wafer worktable 10 and a measurement position grating plane 20; at least three corners of the wafer worktable 10 are provided with readers 11; the measurement position grating plane 20 includes a phase difference grating 22 and multiple groups of zero position gratings 21; each reader 11 corresponds to a group of the zero position gratings 21, and the zero position gratings 21 correspond to the preset zero position of the wafer worktable 10; the zero position gratings 21 are inclined gratings, and each group of the zero position gratings 21 includes multiple parallel zero position grating lines; the line width of the zero position grating lines is different from the line width of the grating lines of the phase difference grating 22. In the present invention, the zero position gratings 21 are added in the measurement position grating plane 20. Since the line width of the zero position gratings 21 is different from that of the phase difference grating 22, they can be recognized by the readers 11 and used as the basis for determining the wafer worktable 10. The present invention does not need to separately add a zero search component, but adds new zero position gratings 21 on the measurement position grating plane 20, adding a new zero search function to the original reader 11 component, greatly simplifying the equipment system, improving the stability of the equipment system at the same time, and prolonging the service life of the equipment.

[0059] On the basis of the first specific embodiment, the grating distribution on the measurement position grating plane 20 is further improved to obtain the second specific embodiment, and its partial structural schematic diagram is as Figure 3 shown, including a wafer worktable 10 and a measurement position grating plane 20;

[0060] At least three corners of the wafer worktable 10 are provided with readers 11;

[0061] The measurement position grating plane 20 includes a phase difference grating 22 and multiple groups of zero position gratings 21;

[0062] Each reader 11 corresponds to a group of the zero position gratings 21, and the zero position gratings 21 correspond to the preset zero position of the wafer worktable 10;

[0063] The zero position gratings 21 are inclined gratings, and each group of the zero position gratings 21 includes multiple parallel zero position grating lines; the line width of the zero position grating lines is different from the line width of the grating lines of the phase difference grating 22;

[0064] The measurement position grating plane 20 includes a zero return area;

[0065] The zero position gratings 21 are arranged in the zero return area, and the phase difference grating 22 is arranged outside the zero return area.

[0066] The difference between this specific implementation and the above-mentioned specific implementation is that in this specific implementation, the positional relationship between the phase difference grating 22 and the zero position grating 21 is specified, and the rest of the structures are the same as those in the above-mentioned specific implementation, so they will not be elaborated here.

[0067] At the zero position (which can be understood as within the zeroing area), if there are two types of grating signals, it will increase the noise. If the resolution ability of the read head 11 is insufficient, it may cause the zeroing failure. Therefore, in this preferred implementation, the phase difference grating 22 near the zero position grating 21 (i.e., within the zeroing area) is removed, and only the zero position grating 21 is retained, thereby greatly improving the signal-to-noise ratio of the signals received by the read head 11, enhancing the recognition accuracy of the device for the zero position grating 21, and further improving the zeroing accuracy.

[0068] The present invention also provides a method for zeroing a machine table applied to a lithography process. The schematic flow diagram of a specific implementation is as Figure 4 shown, which is called the third specific implementation. The method for zeroing a machine table applied to a lithography process is implemented by the machine table applied to a lithography process as described in any one of the above, and includes:

[0069] S101: Perform a preliminary positioning on the wafer workpiece table 10 so that the wafer workpiece table 10 is placed within a preset area to be calibrated 30.

[0070] Please refer to Figure 1 , Figure 1 where the area to be calibrated 30 is marked with a dashed box. The area to be calibrated 30 is an area near the zero position of the wafer worktable. Currently, the machine table can move the wafer workpiece table 10 to the vicinity of the zero position, and then perform fine adjustment in the subsequent steps to align the wafer workpiece table 10 completely with the zero position.

[0071] S102: Perform a step-by-step adjustment on the position of the wafer workpiece table 10 until at least three read heads 11 of the wafer workpiece table 10 can capture the zero position grating 21.

[0072] The step-by-step adjustment means moving the wafer workpiece table 10 step by step according to a preset step until at least three read heads 11 are aligned with the corresponding zero position grating 21.

[0073] S103: Obtain the attitude reading value from the read head 11 that captures the zero position grating 21.

[0074] The attitude reading value is the degree of freedom value in the previous text. For the specific acquisition means, please refer to the previous text and will not be elaborated here.

[0075] S104: Determine the zero position marking information according to the attitude reading value.

[0076] The zero - position marking information is also the accurate position information of the zero - position.

[0077] S105: Adjust the wafer stage 10 to the zero - position according to the zero - position marking information.

[0078] Generally, the zero - position grating 21 can have a different grating width from the phase - difference grating 22, so that different AC / DC values can be obtained, thereby distinguishing the information of the zero - position grating 21. Then, through calculation, the accurate position information (i.e., the zero - position marking information) can be obtained, and then the wafer stage 10 is adjusted to the zero - position.

[0079] The zero - finding method of the machine tool applied to the lithography process in the present invention is in contrast to the machine tool applied to the lithography process in the previous text. Therefore, the specific zero - finding method can refer to the previous text and will not be elaborated here.

[0080] The zero - finding method of the machine tool applied to the lithography process provided by the present invention includes: preliminarily positioning the wafer stage 10 so that the wafer stage 10 is placed in a preset area to be calibrated 30; step - by - step adjusting the position of the wafer stage 10 until at least three read heads 11 of the wafer stage 10 can capture the zero - position grating 21; obtaining an attitude reading value from the read head 11 that captures the zero - position grating 21; determining zero - position marking information according to the attitude reading value; and adjusting the wafer stage 10 to the zero - position according to the zero - position marking information. In the present invention, the zero - position grating 21 is added in the measurement - position grating plane 20. Since the line width of the zero - position grating 21 is different from that of the phase - difference grating 22, it can be recognized by the read head 11 and used as the basis for determining the wafer stage 10. The present invention does not need to add a separate zero - finding component, but adds a new zero - position grating 21 on the measurement - position grating plane 20, adding a new zero - finding function to the original read - head 11 component, greatly simplifying the equipment system, improving the stability of the equipment system, and prolonging the service life of the equipment.

[0081] Next, the zero - finding device of the machine tool applied to the lithography process provided by the embodiments of the present invention will be introduced. The zero - finding device of the machine tool applied to the lithography process described below can be correspondingly referred to the zero - finding method of the machine tool applied to the lithography process described above.

[0082] Figure 5 is the structural block diagram of the zero - finding device of the machine tool applied to the lithography process provided by the embodiments of the present invention. Refer to Figure 5 The zero - finding device of the machine tool applied to the lithography process may include:

[0083] A preliminary positioning module 100, configured to preliminarily position the wafer stage 10 so that the wafer stage 10 is placed in a preset area to be calibrated 30;

[0084] A grating capture module 200 is used to perform step - by - step adjustment on the position of the wafer stage 10 until at least three heads 11 of the wafer stage 10 can capture the zero - position grating 21;

[0085] An attitude reading module 300 is used to obtain an attitude reading value from the head 11 that captures the zero - position grating 21;

[0086] A zero - position marking module 400 is used to determine zero - position marking information according to the attitude reading value;

[0087] An adjustment module 500 is used to adjust the wafer stage 10 to the zero - position according to the zero - position marking information.

[0088] The machine - zero - seeking device applied to the lithography process provided by the present invention includes a preliminary positioning module 100, which is used to perform preliminary positioning on the wafer stage 10 so that the wafer stage 10 is placed in a preset calibration area 30; a grating capture module 200, which is used to perform step - by - step adjustment on the position of the wafer stage 10 until at least three heads 11 of the wafer stage 10 can capture the zero - position grating 21; an attitude reading module 300, which is used to obtain an attitude reading value from the head 11 that captures the zero - position grating 21; a zero - position marking module 400, which is used to determine zero - position marking information according to the attitude reading value; an adjustment module 500, which is used to adjust the wafer stage 10 to the zero - position according to the zero - position marking information. In the present invention, the zero - position grating 21 is added in the measurement - position grating plane 20. Since the line width of the zero - position grating 21 is different from that of the phase - difference grating 22, it can be recognized by the head 11 and used as the basis for determining the wafer stage 10. The present invention does not need to add a separate zero - seeking component, but adds a new zero - position grating 21 on the measurement - position grating plane 20, adding a new zero - seeking function to the original head 11 component, greatly simplifying the equipment system, improving the stability of the equipment system at the same time, and extending the service life of the equipment.

[0089] The machine - zero - seeking device applied to the lithography process in this embodiment is used to implement the aforementioned machine - zero - seeking method applied to the lithography process. Therefore, the specific implementation manners in the machine - zero - seeking device applied to the lithography process can be seen in the embodiment part of the machine - zero - seeking method applied to the lithography process in the previous text. For example, the preliminary positioning module 100, the grating capture module 200, the attitude reading module 300, the zero - position marking module 400, and the adjustment module 500 are respectively used to implement steps S101, S102, S103, S104, and S105 in the aforementioned machine - zero - seeking method applied to the lithography process. Therefore, its specific implementation manners can refer to the descriptions of the corresponding individual part embodiments and will not be elaborated here.

[0090] The present invention also provides a machine zeroing device applied to a lithography process, including:

[0091] A memory for storing a computer program;

[0092] A processor for implementing the steps of the machine zeroing method applied to the lithography process as described in any one of the above when executing the computer program. The machine zeroing method applied to the lithography process provided by the present invention includes performing preliminary positioning on the wafer workpiece stage 10 to place the wafer workpiece stage 10 in a preset area to be calibrated 30; performing step-by-step adjustment on the position of the wafer workpiece stage 10 until at least three read heads 11 of the wafer workpiece stage 10 can capture the zero grating 21; obtaining an attitude readout value from the read head 11 that captures the zero grating 21; determining zero mark information according to the attitude readout value; and adjusting the wafer workpiece stage 10 to the zero position according to the zero mark information. The present invention adds the zero grating 21 in the measurement grating plane 20. Since the line width of the zero grating 21 is different from that of the phase difference grating 22, it can be recognized by the read head 11 and used as the basis for determining the wafer workpiece stage 10. The present invention does not need to separately add a zeroing component, but adds a new zero grating 21 on the measurement grating plane 20, adding a new zeroing function to the original read head 11 component, greatly simplifying the equipment system, improving the stability of the equipment system at the same time, and prolonging the service life of the equipment.

[0093] The present invention also provides a computer-readable storage medium with a computer program stored thereon. When the computer program is executed by a processor, it implements the steps of the machine zeroing method applied to the lithography process as described in any one of the above. The machine zeroing method applied to the lithography process provided by the present invention includes performing preliminary positioning on the wafer workpiece stage 10 to place the wafer workpiece stage 10 in a preset area to be calibrated 30; performing step-by-step adjustment on the position of the wafer workpiece stage 10 until at least three read heads 11 of the wafer workpiece stage 10 can capture the zero grating 21; obtaining an attitude readout value from the read head 11 that captures the zero grating 21; determining zero mark information according to the attitude readout value; and adjusting the wafer workpiece stage 10 to the zero position according to the zero mark information. The present invention adds the zero grating 21 in the measurement grating plane 20. Since the line width of the zero grating 21 is different from that of the phase difference grating 22, it can be recognized by the read head 11 and used as the basis for determining the wafer workpiece stage 10. The present invention does not need to separately add a zeroing component, but adds a new zero grating 21 on the measurement grating plane 20, adding a new zeroing function to the original read head 11 component, greatly simplifying the equipment system, improving the stability of the equipment system at the same time, and prolonging the service life of the equipment.

[0094] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple. For the relevant parts, reference can be made to the description in the method section.

[0095] It should be noted that in this specification, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0096] The above has introduced in detail the machine applied to the lithography process and the zero-search method of the machine applied to the lithography process provided by the present invention. Specific examples are used herein to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A machine tool applied to a lithography process, characterized in that, it includes a wafer worktable and a measurement position grating plane; At least three corners of the wafer worktable are provided with readers; The measurement position grating plane includes a phase difference grating and multiple groups of zero position gratings; Each reader corresponds to a group of the zero position gratings, and the zero position gratings correspond to a preset zero position of the wafer worktable; The zero position gratings are inclined gratings, and each group of the zero position gratings includes multiple parallel zero position grating lines; the line width of the zero position grating lines is different from the line width of the grating lines of the phase difference grating.

2. The machine tool applied to a lithography process according to claim 1, characterized in that, One kind of the grating lines of the zero position grating lines is parallel to the grating lines of the phase difference grating.

3. The machine tool applied to a lithography process according to claim 2, characterized in that, All the zero position grating lines are parallel to each other.

4. The machine tool applied to a lithography process according to claim 2, characterized in that, The inclination angle of the zero position grating is 45 degrees.

5. The machine tool applied to a lithography process according to claim 1, characterized in that, The line width of the zero position grating lines is greater than the line width of the grating lines of the phase difference grating.

6. The machine tool applied to a lithography process according to claim 1, characterized in that, The distance between adjacent zero position grating lines in the zero position grating is not greater than 2048 nanometers.

7. The machine tool applied to a lithography process according to claim 1, characterized in that, The reader is a two-dimensional reader.

8. The machine tool applied to a lithography process according to claim 1, characterized in that, Readers are provided at four corners of the wafer worktable.

9. The machine tool applied to a lithography process according to any one of claims 1 to 8, characterized in that, The measurement position grating plane includes a zeroing area; The zero position gratings are arranged in the zeroing area, and the phase difference grating is arranged outside the zeroing area.

10. A zeroing method for a machine tool applied to a lithography process, characterized in that, The zeroing method for the machine tool applied to a lithography process is implemented by the machine tool applied to a lithography process according to any one of claims 1 to 9, and includes: Performing preliminary positioning on the wafer worktable to place the wafer worktable in a preset area to be calibrated; Performing step-by-step adjustment on the position of the wafer worktable until at least three readers of the wafer worktable can capture the zero position gratings; Obtaining an attitude reading value from the readers that capture the zero position gratings; Determining zero position mark information according to the attitude reading value; Adjusting the wafer worktable to the zero position according to the zero position mark information.

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