Exposure period adjustment apparatus and method

Abstract

This invention provides an exposure period adjustment device and method, relating to the field of ultra-precision measurement. The device includes a control module and first, second, third, and fourth motorized mirror groups connected to the control module, as well as first and second position detectors and a period measurement module. It also includes first and second beam splitters and first and second decoupling lenses. A first incident beam can pass sequentially through the second motorized mirror group, the first motorized mirror group, and the first beam splitter; a second incident beam can pass sequentially through the fourth motorized mirror group, the third motorized mirror group, and the first beam splitter; the two incident beams have the same incident point at the first beam splitter; the beam split by the first beam splitter has one path that enters the period measurement module, and the other path that passes through the second beam splitter; the beam split by the second beam splitter has one path that passes through the first decoupling lens and reaches the first position detector, and the other path that passes through the second decoupling lens and reaches the second position detector. This device offers high adjustment accuracy and a wide range of applications.

Description

Technical Field

[0001] This invention relates to the field of ultra-precision measurement technology, and more specifically, to an exposure cycle adjustment device and method. Background Technology

[0002] Photolithography machines are key equipment in semiconductor manufacturing, used to produce chips. Two-dimensional reflective gratings are the core component of the ultra-precision stage grating displacement measurement system in photolithography machines. Scanning interferometry (SIL) lithography machines utilize the interference properties of light to create periodic interference fringes between two incident light beams at the exposure position to produce gratings. The exposure period is directly determined by the incident angle of the exposure light path; therefore, precise measurement and control of the incident angle are crucial during grating fabrication.

[0003] In the existing technology, the method of adjusting the exposure period of a scanning interference lithography machine is to use the Litterow effect of a standard grating to make the incident light of the exposure beam coincide with its -1st order diffracted light to obtain the exposure interference angle. However, the exposure period calculated by obtaining the exposure interference angle in this way differs greatly from the expected value. That is, the adjustment accuracy of the exposure period is low and the application range is small. Summary of the Invention

[0004] The first objective of this invention is to provide an exposure period adjustment device to solve the technical problems of low adjustment accuracy and limited applicability of existing exposure period adjustment methods.

[0005] The exposure period adjustment device provided by the present invention includes a control module and a first motorized mirror group, a second motorized mirror group, a third motorized mirror group, a fourth motorized mirror group, a first position detector, a second position detector, and a period measurement module connected to the control module. It also includes a first beam splitter, a second beam splitter, a first decoupling lens, and a second decoupling lens.

[0006] The first and second motorized lens groups jointly adjust the exposure position and incident angle of the first incident beam; the third and fourth motorized lens groups jointly adjust the exposure position and incident angle of the second incident beam.

[0007] The first incident beam can pass sequentially through the second motorized mirror group, the first motorized mirror group, and the first beam splitter; the second incident beam can pass sequentially through the fourth motorized mirror group, the third motorized mirror group, and the first beam splitter; the first incident beam and the second incident beam have the same incident point at the first beam splitter; the beam split by the first beam splitter enters the period measurement module in one path and passes through the second beam splitter in the other path; the beam split by the second beam splitter passes through the first decoupling lens and arrives at the first position detector in one path and passes through the second decoupling lens and arrives at the second position detector in the other path.

[0008] Furthermore, the first beam splitter is a cubic beam splitter.

[0009] Furthermore, the second beam splitter is a flat beam splitter.

[0010] Furthermore, the exposure period adjustment device also includes a first reflector, the incident light beam of the first reflector originating from the first beam splitter, and the outgoing light beam of the first reflector incident on the second beam splitter.

[0011] Furthermore, the exposure period adjustment device also includes a second reflector, the incident light beam of which comes from the second beam splitter, and the outgoing light beam of which is incident on the first decoupling lens.

[0012] Furthermore, the first motorized mirror assembly, the second motorized mirror assembly, the third motorized mirror assembly, and the fourth motorized mirror assembly all include a motorized mirror mount and a reflector, with the reflector disposed on the motorized mirror mount.

[0013] The exposure period adjustment device provided by the present invention can produce the following beneficial effects:

[0014] The exposure period adjustment device provided by this invention can adjust the exposure position and incident angle of the first and second incident beams used to generate interference light, respectively. When the two incident beams are incident simultaneously, the actual exposure period of the grating fringes generated by the two incident beams can be measured using the period measurement module. Then, the two incident beams are incident separately. Taking the adjustment of the first incident beam as an example (the adjustment of the second incident beam can refer to the adjustment process of the first incident beam): the first incident beam passes through the second motorized mirror group and the first motorized mirror group in sequence, and is split at the first beam splitter. After splitting, one beam is incident to the second beam splitter, and is split again at the second beam splitter. After the second split, one beam passes through the first decoupling lens and arrives at the first position detector, while the other beam passes through the second decoupling lens and arrives at the second position detector. In this way, the actual exposure position value and actual incident angle value of the first incident beam can be obtained. The control module can determine the target exposure position and target exposure angle based on the actual and target exposure periods of the first incident beam, as well as the actual exposure position and actual incident angle. It then further determines the exposure position adjustment and incident angle adjustment values, and drives the first and second motorized mirror groups to adjust the exposure position and incident angle of the first incident beam. After adjusting the first incident beam, the exposure position and incident angle of the second incident beam are adjusted according to the adjustment process of the first incident beam, thus completing the first adjustment. After the first adjustment, if the difference between the actual exposure period and the target exposure period of the grating fringes produced by the incident beams does not meet the error requirement, the above steps can be repeated for a second adjustment until the difference between the actual exposure period and the target exposure period of the grating fringes produced by the two incident beams meets the error requirement. That is, using the exposure period adjustment device provided by this invention, the exposure position and incident angle of the two incident beams can be iteratively adjusted until the actual exposure period of the grating fringes produced by them meets the requirements. Therefore, the exposure period adjustment device provided by this invention has high adjustment accuracy and a wide range of applications.

[0015] The second objective of this invention is to provide an exposure period adjustment method to solve the technical problems of low adjustment accuracy and limited applicability of existing exposure period adjustment methods.

[0016] The exposure period adjustment method provided by the present invention, using the above-mentioned exposure period adjustment device, includes the following steps:

[0017] The S100 measures the actual exposure period of the grating fringes produced by the two incident beams.

[0018] S200 determines whether the difference between the actual exposure period and the target exposure period meets the error requirement;

[0019] S300 If the difference between the actual exposure period and the target exposure period does not meet the error requirement, then based on the actual exposure period, the target exposure period, the actual exposure position value and the actual incident angle value of the two incident beams, calculate the exposure position adjustment value and the incident angle adjustment value of the two incident beams respectively, and adjust the exposure position and incident angle of the two incident beams respectively based on the corresponding exposure position adjustment value and the incident angle adjustment value.

[0020] S400 Repeat steps S100 to S300 until the difference between the actual exposure period and the target exposure period meets the error requirement.

[0021] Further, the step of calculating the exposure position adjustment value and the incident angle adjustment value of the incident beam based on the actual exposure period, the target exposure period, the actual exposure position values ​​and the actual incident angle values ​​of the two incident beams, respectively, includes:

[0022] S301 detects the actual exposure position value and the actual incident angle value of the two incident beams;

[0023] S302 determines the target exposure position value and target incident angle value of the two incident beams respectively based on the actual exposure period, the target exposure period, the actual exposure position value and the actual incident angle value of the two incident beams;

[0024] S303 calculates the difference between the actual exposure position value and the target exposure position value of each of the two incident beams, and uses it as the exposure position adjustment value for each of them; calculates the difference between the actual incident angle value and the target incident angle value of each of the two incident beams, and uses it as the incident angle adjustment value for each of them.

[0025] Furthermore, the exposure period adjustment method further includes:

[0026] S500 If the difference between the actual exposure period and the target exposure period meets the error requirement, then the exposure position and incident angle of the incident beam remain unchanged.

[0027] The exposure cycle adjustment method provided by this invention can produce the following beneficial effects:

[0028] The exposure period adjustment method provided by this invention uses the aforementioned exposure period adjustment device to adjust the exposure period of the grating fringes generated by two incident beams. After adjusting the exposure position and incident angle of the two incident beams respectively, if the difference between the actual exposure period and the target exposure period of the grating fringes generated by the two incident beams does not meet the error requirement, a second adjustment is performed on the two incident beams until the difference between the actual exposure period and the target exposure period of the grating fringes generated by the two incident beams meets the error requirement. That is, the exposure period adjustment method provided by this invention iteratively adjusts the exposure position and incident angle of the incident beams to ensure that the actual exposure period of the grating fringes generated by the incident beams meets the requirements, achieving high adjustment accuracy and wide applicability. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0030] Figure 1 A schematic diagram of the exposure period adjustment device provided by the present invention;

[0031] Figure 2 A partial optical path diagram of the incident beam before and after adjustment using the exposure period adjustment device provided by the present invention;

[0032] Figure 3 The present invention provides a logic flowchart for the exposure cycle adjustment method.

[0033] Explanation of reference numerals in the attached figures:

[0034] 110 - First motorized lens group; 120 - Second motorized lens group; 130 - Third motorized lens group; 140 - Fourth motorized lens group;

[0035] 200 - First beam splitter;

[0036] 300 - First reflecting mirror;

[0037] 400 - Second beam splitter;

[0038] 500 - Second reflecting mirror;

[0039] 610 - First decoupling lens; 710 - First position detector;

[0040] 620 - Second decoupling lens; 720 - Second position detector;

[0041] 800-cycle measurement module;

[0042] 900-Control Module;

[0043] a - Adjusted beam; b - Unadjusted beam; p - Exposure point. Detailed Implementation

[0044] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0045] This embodiment provides an exposure period adjustment device, such as... Figure 1 As shown, the exposure period adjustment device includes a control module 900 and a first motorized mirror group 110, a second motorized mirror group 120, a third motorized mirror group 130, a fourth motorized mirror group 140, a first position detector 710, a second position detector 720, and a period measurement module 800, all connected to the control module 900. It also includes a first beam splitter 200, a second beam splitter 400, a first decoupling lens 610, and a second decoupling lens 620. The first motorized mirror group 110 and the second motorized mirror group 120 jointly adjust the exposure position and incident angle of the first incident beam, while the third motorized mirror group 130 and the fourth motorized mirror group 140 jointly adjust the exposure position and incident angle of the first incident beam. The first incident beam can pass sequentially through the second motorized mirror group 120, the first motorized mirror group 110, and the first beam splitter 200; the second incident beam can pass sequentially through the fourth motorized mirror group 140, the third motorized mirror group 130, and the first beam splitter 200; the first and second incident beams have the same incident point at the first beam splitter 200; the beam split by the first beam splitter 200 is incident on the period measurement module 800 in one direction and passes through the second beam splitter 400 in the other direction; the beam split by the second beam splitter 400 passes through the first decoupling lens 610 and arrives at the first position detector 710 in one direction and passes through the second decoupling lens 620 and arrives at the second position detector 720 in the other direction.

[0046] The exposure period adjustment device provided in this embodiment can adjust the exposure position and incident angle of the first incident beam and the second incident beam used to generate interference light, respectively. When the two incident beams are incident simultaneously, the actual exposure period of the grating fringes generated by the two incident beams can be measured by the period measurement module 800. Then, the two incident beams are incident separately. Taking the adjustment of the first incident beam as an example (the adjustment of the second incident beam can refer to the adjustment process of the first incident beam): the first incident beam passes through the second motorized mirror group 120 and the first motorized mirror group 110 in sequence, and is split at the first beam splitter 200. After splitting, one beam is incident to the second beam splitter 400, and is split again at the second beam splitter 400. After splitting again, one beam passes through the first decoupling lens 610 and arrives at the first position detector 710, while the other beam passes through the second decoupling lens 620 and arrives at the second position detector 720. In this way, the actual exposure position value and actual incident angle value of the first incident beam can be obtained. The control module 900 can determine the target exposure position and target exposure angle based on the actual exposure period and target exposure period of the first incident beam, as well as the actual exposure position and actual incident angle. It then determines the exposure position adjustment value and incident angle adjustment value, and drives the first motorized mirror group 110 and the second motorized mirror group 120 to adjust the exposure position and incident angle of the first incident beam. After adjusting the first incident beam, the exposure position and incident angle of the second incident beam are adjusted according to the adjustment process of the first incident beam, thus completing the first adjustment. After the first adjustment, if the difference between the actual exposure period and the target exposure period of the grating fringes produced by the incident beams does not meet the error requirement, the above steps can be repeated for a second adjustment until the difference between the actual exposure period and the target exposure period of the grating fringes produced by the two incident beams meets the error requirement. That is, using the exposure period adjustment device provided in this embodiment, the exposure position and incident angle of the two incident beams can be iteratively adjusted until the actual exposure period of the grating fringes produced by them meets the requirement. Therefore, the exposure period adjustment device provided in this embodiment has high adjustment accuracy and a wide range of applications.

[0047] It should be noted that in this application, the period measurement module 800 uses a PD (Photoelectric Detector) to calculate the exposure period by detecting changes in the light intensity of the interference signal, which is existing technology; the first position detector 710 and the second position detector 720 both use PSD (Position Sensitive Detector), which can decouple and obtain the position or angle information of the beam, which is existing technology; the first motorized mirror group 110 and the second motorized mirror group 120 jointly adjust the exposure position and incident angle of the first incident beam, and the third motorized mirror group 130 and the fourth motorized mirror group 140 jointly adjust the exposure position and incident angle of the second incident beam, which is also existing technology. Therefore, this application will not elaborate on the specific structures and working principles involved above.

[0048] Specifically, in this embodiment, the first beam splitter 200 is a cubic beam splitter. For example... Figure 2 As shown in the figure, point p is the exposure point. Using a cubic beam splitter ensures that the exposure point of the incident beam remains unchanged before and after adjustment, simplifying the adjustment process. Of course, in other embodiments of this application, the first beam splitter 200 can also be a flat beam splitter, and the exposure point of the incident beam can be kept constant by adjusting each motorized mirror group.

[0049] Specifically, in this embodiment, the second beam splitter 400 is a flat beam splitter.

[0050] Specifically, in this embodiment, as Figure 1 As shown, the exposure period adjustment device also includes a first reflecting mirror 300. The incident light beam from the first reflecting mirror 300 originates from the first beam splitter 200, and the outgoing light beam from the first reflecting mirror 300 is incident on the second beam splitter 400. With this configuration, the first reflecting mirror 300 functions to change the propagation direction of the incident light beam, so as to... Figure 1 From the perspective of the first reflector 300, the incident beam that is generally propagating in the vertical direction is changed to be generally propagating in the horizontal direction, making the structure of the entire adjustment device more compact and coordinated. At the same time, it is also conducive to reducing the size of the entire adjustment device, thereby reducing the space requirements of the adjustment device.

[0051] Specifically, in this embodiment, the following continues... Figure 1 As shown, the exposure period adjustment device also includes a second reflecting mirror 500. The incident light beam from the second reflecting mirror 500 originates from the second beam splitter 400, and the outgoing light beam from the second reflecting mirror 500 is incident on the first decoupling lens 610. Similar to the function of the first reflecting mirror 300, the second reflecting mirror 500 also serves to change the propagation direction of the incident light beam. Figure 1From the perspective of the first reflector 300, the incident beam that is propagating in a roughly horizontal direction is changed to propagating in a roughly vertical direction. The use of the second reflector 500 further improves the structural compactness and coordination of the entire adjustment device, and also further reduces the volume of the entire adjustment device, thereby further reducing the space requirements of the adjustment device.

[0052] Specifically, in this embodiment, the first motorized mirror group 110, the second motorized mirror group 120, the third motorized mirror group 130, and the fourth motorized mirror group 140 each include a motorized mirror mount and a reflector, with the reflector disposed on the motorized mirror mount. The control module 900 controls the position and angle of the reflector disposed on the motorized mirror mount by controlling the position and angle of the motorized mirror mount, thereby controlling the incident angle and exposure period of the incident light beam.

[0053] More specifically, the control module 900 can be a computer, such as a personal computer.

[0054] In summary, the exposure period adjustment device provided in this embodiment adjusts the two incident beams separately during use. The specific steps are as follows:

[0055] The first incident beam passes sequentially through the second motorized mirror group 120 and the first motorized mirror group 110 to form the first incident beam. Then, it passes sequentially through the cubic beam splitter and the first reflecting mirror 300 before reaching the flat beam splitter, where it is split. One beam passes through the second decoupling lens 620 and enters the second position detector 720, where the exposure position information of the beam is obtained through decoupling calculation. The other beam passes through the second reflecting mirror 500 and the first decoupling lens 610 and enters the first position detector 710, where the incident angle information of the beam is obtained through decoupling calculation.

[0056] The exposure period of the scanning interference lithography machine is obtained through the period measurement module 800 and input into the computer. Then, the first and second incident beams are individually incident. Taking the first incident beam as an example, the computer first obtains the actual exposure position and actual incident angle information of the first incident beam through the first position detector 710 and the second position detector 720. The computer calculates the difference between the actual incident angle and the target incident angle of the first incident beam by measuring the actual exposure period and the preset target exposure period. Based on the overall optical path position information, it calculates the value at the second position detector 720 after the beam passes the exposure point when the angle changes. Figure 2As shown. The calculated angle and position values ​​are input into the first position detector 710 and the second position detector 720 as reference points, respectively. This drives the first motorized mirror group 110 and the second motorized mirror group 120, causing the detection values ​​of the first incident beam on the first and second position detectors 710 and 720 to coincide with the set reference points, thus completing the first correction of the first incident beam. After completing the first correction of the first incident beam, the second incident beam is corrected for the first time using the same process.

[0057] Then, a second period measurement is performed on the scanning interferometry lithography machine to obtain the corrected period. If the corrected period still does not meet the requirements, the value at the second position detector 720 after the first incident beam passes through the exposure point is detected. Figure 2 As shown. Using the target incident angle value and target exposure position value as reference points, the first position detector 710 and the second position detector 720 are respectively input into them. The first motorized mirror group 110 and the second motorized mirror group 120 are driven to make the detected values ​​of the first incident beam on the first position detector 710 and the second position detector 720 coincide with the set reference points, completing the second correction of the incident beam. The second correction is completed, and the exposure point position remains unchanged. After the second correction of the first incident beam is completed, the second incident beam is corrected a second time, referring to the above process. The above steps are repeated until the actual exposure period measured by the period measurement module 800 is consistent with the target exposure period (within the recognized difference range), at which point the period iteration adjustment process ends.

[0058] The adjustment process for the second incident beam is the same as that for the first incident beam, and will not be repeated here.

[0059] Figure 2 This is a partial optical path diagram showing the incident beam before and after adjustment using the exposure period adjustment device provided in this embodiment. (See diagram below.) Figure 2 As shown, before adjustment, assuming the complementary angle of the incident beam (i.e., beam b in the figure) at the incident angle of the stereo beam splitter is θ, then the value of ∠Ⅰ is θ; assuming ∠Ⅱ is the minimum adjustment amount of the incident beam angle by the motorized mirror mount, and its value is Δθ, then ∠Ⅱ=Δθ; the placement angles α and β of the first reflecting mirror 300 and the second beam splitter 400 are known, so we can obtain that before adjustment, the incident angle of the incident beam at the first reflecting mirror 300 is:

[0060] ∠Ⅲ=π / 2-(π / 2-∠α-∠Ⅰ)=∠α+∠Ⅰ

[0061] After adjustment, the incident angle of the incident beam (i.e., beam a in the figure) at the first reflecting mirror 300 is:

[0062] ∠Ⅳ=π / 2-(π / 2-∠α-∠Ⅱ-∠Ⅰ)=∠α+∠Ⅱ+∠Ⅰ

[0063] According to the law of reflection, it can be further deduced that, before adjustment, the reflection angle of the incident beam at the second beam splitter 40° is:

[0064] ∠Ⅴ=π / 2-(∠α+∠β-∠Ⅲ)

[0065] After adjustment, the reflection angle of the incident beam at the second beam splitter 400 is:

[0066] ∠Ⅵ=π / 2-(∠α+∠β-∠Ⅳ)

[0067] When the incident angle changes ∠Ⅱ, the angle change of the light entering the position detector is Δδ=∠Ⅵ-∠Ⅴ=∠Ⅱ, which means that the angle change of the light entering the position detector is the same as the initial angle change of the incident light. Therefore, the minimum change of the interference angle is twice the minimum adjustment of the motorized mirror group.

[0068] Assuming the period before adjustment of the scanning interference lithography machine is P, the corresponding exposure interference angle is... By adjusting ∠β to ensure proper incident illumination, the first decoupling lens 610, the first position detector 710, the second decoupling lens 620, and the second position detector 720 are all perpendicularly incident. The adjusted beam angle is... If the focal length of the first decoupling lens 610 and the second decoupling lens 620 is f, then the position change on the first position detector 710 is:

[0069]

[0070]

[0071] The distance from the second decoupling lens 620 to the second position detector 720 is f + Δf, and the distance from the exposure point to the second decoupling lens 620 is L. Then, the position change of the light beam on the second position detector 720 is:

[0072]

[0073] Using the above formula, along with motorized mirror groups, decoupling lenses, and position detectors, the exposure period can be adjusted to vary by 0.1 nm.

[0074] This embodiment also provides a method for adjusting the exposure period, such as... Figure 3 As shown, this method uses the aforementioned exposure period adjustment device and includes the following steps:

[0075] The S100 measures the actual exposure period of the grating fringes produced by the two incident beams.

[0076] S200 determines whether the difference between the actual exposure period and the target exposure period meets the error requirements;

[0077] If the difference between the actual exposure period and the target exposure period does not meet the error requirements, S300 calculates the exposure position adjustment value and the incident angle adjustment value of the two incident beams respectively based on the actual exposure period, the target exposure period, the actual exposure position value and the actual incident angle value of the two incident beams, and adjusts the exposure position and incident angle of the incident beams according to the corresponding exposure position adjustment value and incident angle adjustment value.

[0078] S400 Repeat steps S100 to S300 until the difference between the actual exposure period and the target exposure period meets the error requirement.

[0079] The exposure period adjustment method provided in this embodiment uses the aforementioned exposure period adjustment device to adjust the exposure period of the grating fringes generated by two incident beams. After adjusting the exposure position and incident angle of the two incident beams respectively, if the difference between the actual exposure period and the target exposure period of the grating fringes generated by the two incident beams does not meet the error requirement, the two incident beams are adjusted a second time until the difference between the actual exposure period and the target exposure period of the grating fringes generated by the two incident beams meets the error requirement. That is, the exposure period adjustment method provided in this embodiment iteratively adjusts the exposure position and incident angle of the incident beams to ensure that the actual exposure period of the grating fringes generated by the incident beams meets the requirements, resulting in high adjustment accuracy and wide applicability.

[0080] Specifically, in this embodiment, the following continues... Figure 3 As shown, the exposure cycle adjustment method also includes:

[0081] If the difference between the actual exposure period and the target exposure period meets the error requirements, the S500 will keep the exposure position and incident angle of the incident beam unchanged.

[0082] Specifically, in this embodiment, based on the actual exposure period, the target exposure period, the actual exposure position values ​​of the two incident beams, and the actual incident angle values, the exposure position adjustment value and the incident angle adjustment value of the incident beams are calculated respectively, including:

[0083] The S301 detects the actual exposure position and actual incident angle of two incident beams;

[0084] S302 determines the target exposure position value and target incident angle value of the two incident beams based on the actual exposure period, the target exposure period, the actual exposure position value and the actual incident angle value of the two incident beams respectively.

[0085] S303 calculates the difference between the actual exposure position value and the target exposure position value of each of the two incident beams, and uses it as the exposure position adjustment value for each beam; it also calculates the difference between the actual incident angle value and the target incident angle value of each of the two incident beams, and uses it as the incident angle adjustment value for each beam.

[0086] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0087] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to the embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An exposure period adjustment device, characterized in that, It includes a control module (900) and a first motorized mirror group (110), a second motorized mirror group (120), a third motorized mirror group (130), a fourth motorized mirror group (140), a first position detector (710), a second position detector (720), and a period measurement module (800) connected to the control module (900). It also includes a first beam splitter (200), a second beam splitter (400), a first decoupling lens (610), and a second decoupling lens (620). The first motorized mirror group (110) and the second motorized mirror group (120) jointly adjust the exposure position and incident angle of the first incident beam, and the third motorized mirror group (130) and the fourth motorized mirror group (140) jointly adjust the exposure position and incident angle of the second incident beam. The first incident beam can pass sequentially through the second motorized mirror group (120), the first motorized mirror group (110), and the first beam splitter (200); the second incident beam can pass sequentially through the fourth motorized mirror group (140), the third motorized mirror group (130), and the first beam splitter (200); the first incident beam and the second incident beam have the same incident point at the first beam splitter (200); the beam split by the first beam splitter (200) is incident on the period measurement module (800) in one direction and passes through the second beam splitter (400) in the other direction; the beam split by the second beam splitter (400) passes through the first decoupling lens (610) and arrives at the first position detector (710) in one direction and passes through the second decoupling lens (620) and arrives at the second position detector (720) in the other direction. The period measurement module (800) is used to measure the actual exposure period of the grating stripes generated by the two incident beams when the first incident beam and the second incident beam are incident simultaneously. The first position detector (710) is used to obtain the incident angle information of the corresponding incident beam through decoupling calculation when the first incident beam and the second incident beam are incident separately; the second position detector (720) is used to obtain the exposure position information of the corresponding incident beam through decoupling calculation when the first incident beam and the second incident beam are incident separately. The control module (900) determines the target exposure position value and the target exposure angle value based on the actual exposure period and the target exposure period of the first incident beam, as well as the actual exposure position value and the actual incident angle value, and further determines the exposure position adjustment value and the incident angle adjustment value; drives the first motorized mirror group (110) and the second motorized mirror group (120) to adjust the exposure position and the incident angle of the first incident beam; after the adjustment of the first incident beam is completed, the exposure position and the incident angle of the second incident beam are adjusted with reference to the adjustment process of the first incident beam to complete the first adjustment; after the first adjustment is completed, if the difference between the actual exposure period and the target exposure period of the grating stripes produced by the incident beam does not meet the error requirement, the above steps are repeated for the second adjustment until the difference between the actual exposure period and the target exposure period of the grating stripes produced by the two incident beams meets the error requirement.

2. The exposure period adjustment device according to claim 1, characterized in that, The first beam splitter (200) is a cubic beam splitter.

3. The exposure period adjustment device according to claim 1, characterized in that, The second beam splitter (400) is a flat beam splitter.

4. The exposure period adjustment device according to claim 1, characterized in that, The exposure cycle adjustment device further includes a first reflector (300), the incident beam of the first reflector (300) comes from the first beam splitter (200), and the outgoing beam of the first reflector (300) is incident on the second beam splitter (400).

5. The exposure period adjustment device according to claim 1, characterized in that, The exposure period adjustment device further includes a second reflector (500), the incident light beam of the second reflector (500) comes from the second beam splitter (400), and the outgoing light beam of the second reflector (500) is incident on the first decoupling lens (610).

6. The exposure period adjustment device according to any one of claims 1-5, characterized in that, The first motorized mirror assembly (110), the second motorized mirror assembly (120), the third motorized mirror assembly (130) and the fourth motorized mirror assembly (140) each include a motorized mirror mount and a reflector, with the reflector disposed on the motorized mirror mount.

7. A method for adjusting the exposure period, characterized in that, Using the exposure cycle adjustment device according to any one of claims 1-6 includes the following steps: The S100 measures the actual exposure period of the grating fringes produced by the two incident beams. S200 determines whether the difference between the actual exposure period and the target exposure period meets the error requirement; S300 If the difference between the actual exposure period and the target exposure period does not meet the error requirement, then based on the actual exposure period, the target exposure period, the actual exposure position value and the actual incident angle value of the two incident beams, calculate the exposure position adjustment value and the incident angle adjustment value of the two incident beams respectively, and adjust the exposure position and incident angle of the two incident beams respectively based on the corresponding exposure position adjustment value and the incident angle adjustment value. S400 Repeat steps S100 to S300 until the difference between the actual exposure period and the target exposure period meets the error requirement.

8. The exposure period adjustment method according to claim 7, characterized in that, The step of calculating the exposure position adjustment value and the incident angle adjustment value of the two incident beams based on the actual exposure period, the target exposure period, the actual exposure position value and the actual incident angle value of the two incident beams includes: S301 detects the actual exposure position value and actual incident angle value of the two incident beams; S302 determines the target exposure position value and target incident angle value of the two incident beams respectively based on the actual exposure period, the target exposure period, the actual exposure position value and the actual incident angle value of the two incident beams; S303 calculates the difference between the actual exposure position value and the target exposure position value of each of the two incident beams, and uses it as the exposure position adjustment value for each of them; calculates the difference between the actual incident angle value and the target incident angle value of each of the two incident beams, and uses it as the incident angle adjustment value for each of them.

9. The exposure period adjustment method according to claim 7 or 8, characterized in that, The exposure cycle adjustment method further includes: S500 If the difference between the actual exposure period and the target exposure period meets the error requirement, then the exposure position and incident angle of the incident beam remain unchanged.

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