Grating interference exposure system and method

Abstract

The invention discloses a grating interference exposure system and method, and relates to the technical field of information optics, and the grating interference exposure system comprises a coherent light generation assembly, a first interference exposure assembly, a second interference exposure assembly, a mechanical motion assembly, a pose correction assembly, a control assembly, at least one reference grating and a substrate, the substrate and the at least one reference grating are arranged on the mechanical motion assembly at intervals, and the substrate is coated with a photosensitive material. The coherent light for exposure is additionally led out of the exposure area needing exposure through the first interference exposure assembly and the second interference exposure assembly, namely the reference grating, and the pose error between the interference exposure field on the substrate and the mechanical motion system is corrected by using the pose correction assembly. The limitation of one-dimensional splicing of traditional splicing exposure is broken through, pose correction of an interference exposure system under two-dimensional splicing of any number of times can be realized, and a high-precision large-breadth grating is prepared.

Description

Technical Field

[0001] The present application relates to the field of information optics technology, and more specifically, to a grating interference exposure system and method. Background Art

[0002] Large-format gratings have very important applications in many technical fields. The mainstream methods for preparing large-format gratings include mechanical ruling method, electron beam direct writing method and interference exposure method. Among them, benefiting from the parallel exposure principle of optical interference effect, the interference exposure method has the advantages of high efficiency, low cost and high precision. It is the mainstream method for preparing large-format gratings. Furthermore, the interference exposure method includes single large-format exposure method and splicing exposure method.

[0003] However, the current method of preparing large-format gratings by splicing exposure has problems such as high difficulty and insufficient precision in two-dimensional splicing exposure. Summary of the invention

[0004] The present application proposes a grating interference exposure system and method to improve the above-mentioned defects.

[0005] In a first aspect, an embodiment of the present application provides a grating interference exposure system, comprising a coherent light generating component, a first interference exposure component, a second interference exposure component, a mechanical motion component, a posture correction component, a control component, at least one reference grating and a substrate, wherein the substrate and at least one reference grating are spaced apart on the mechanical motion component, and the substrate is coated with a photosensitive material; wherein the coherent light generating component is used to generate at least two beams of coherent light, and at least two beams of coherent light are converged on the substrate through the first interference exposure component to form an interference exposure field, and at least two beams of coherent light are converged on the substrate through the first interference exposure component to form an interference exposure field. and the second interference exposure component converge on the reference grating to form reference grating interference fringes; the control component is connected to the coherent light generating component, the mechanical motion component and the posture correction component, and the control component is used to control the movement of the mechanical motion component to move the substrate and the reference grating carried by the mechanical motion component, so that at least two beams of the coherent light can converge on different first interference exposure areas of the substrate; the control component is also used to control the posture correction component to correct the posture error between the interference exposure field and the mechanical motion component based on the reference grating interference fringes.

[0006] In a second aspect, an embodiment of the present application further provides a grating interference exposure method, which is applied to the above-mentioned grating interference exposure system, and the method includes: starting the coherent light generating component to generate at least two beams of coherent light, part of the at least two beams of coherent light pass through the first interference exposure component to form an interference exposure field, and part of the at least two beams of coherent light pass through the first interference exposure component and the second exposure component to be incident on the reference grating to form reference grating reference stripes; controlling the phase locking component to compensate for the phase drift of the interference exposure field based on at least two beams of coherent light; controlling the movement of the mechanical motion component, while exposing multiple interference exposure areas on the substrate, controlling the posture correction component to correct the posture error between the interference exposure field and the mechanical motion system based on the reference grating interference stripes.

[0007] The present application provides a grating interference exposure system, including a coherent light generating component, a first interference exposure component, a second interference exposure component, a mechanical motion component, a posture correction component, a control component, at least one reference grating and a substrate, wherein the substrate and at least one reference grating are arranged on the mechanical motion component at intervals, and the substrate is coated with a photosensitive material. In this system, at least two beams of coherent light generated by the coherent light generating component are partially converged on the substrate through the first interference exposure component to form an interference exposure field, and partially converged on the reference grating through the first interference exposure component and the second interference exposure component to form reference grating interference fringes. The control component controls the posture correction component to correct the posture error between the first interference exposure field and the mechanical motion system during the splicing exposure process based on the reference grating interference fringes. The present application ensures that the coherent light used for exposure is additionally led out to the outside of the exposure area to be exposed, that is, on the reference grating for posture correction, so as to ensure that the coherent light used for exposure is corrected in the mechanical motion component. In the process of driving the substrate to move so that the interference exposure field generated by the coherent light exposes the entire substrate, the additional coherent light induced can always form reference light interference fringes on the reference grating at the same time, avoiding the use of the original coherent light to form reference grating interference fringes on the reference grating for posture correction in traditional splicing exposure. There may be a problem that the coherent light cannot be directed to the reference grating during the movement of the mechanical motion component, that is, the reference grating interference fringes cannot be generated. This breaks through the limitation of one-dimensional splicing of traditional splicing exposure, and can realize the posture correction of the interference exposure system under any number of two-dimensional splicing, thereby preparing high-precision large-format gratings.

[0008] Other features and advantages of the embodiments of the present application will be described in the subsequent description, and partly become apparent from the description, or can be understood by practicing the embodiments of the present application. The purposes and other advantages of the embodiments of the present application can be realized and obtained by the structures specifically pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0010] Figure 1 A structural block diagram of a grating interference exposure system proposed according to an embodiment of the present application is shown.

[0011] Figure 2 A schematic structural diagram of a grating interference exposure system proposed according to an embodiment of the present application is shown.

[0012] Figure 3 A schematic diagram of the combined structure of a mechanical motion component, a substrate and a reference grating proposed according to an embodiment of the present application is shown.

[0013] Figure 4 A schematic diagram showing the formation of reference grating interference fringes between coherent light and a reference grating according to an embodiment of the present application is shown.

[0014] Figure 5 A schematic diagram showing the changes in the reference grating interference fringes provided according to an embodiment of the present application is shown.

[0015] Figure 6 A schematic structural diagram of a second active device provided according to an embodiment of the present application is shown.

[0016] Figure 7 A schematic structural diagram of another second active device provided according to an embodiment of the present application is shown.

[0017] Figure 8 A schematic structural diagram of a grating interference exposure system using another first interference exposure component according to an embodiment of the present application is shown.

[0018] Fig. 9 A method flow chart of a grating interference exposure method proposed according to an embodiment of the present application is shown.

[0019] Fig.10 A schematic diagram showing the positions of a substrate and a reference grating on a mechanical motion component during an interference exposure process according to an embodiment of the present application is shown.

[0020] Fig.11 A schematic diagram showing the positions of a substrate and a reference grating on a mechanical motion component during another interference exposure process proposed according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0021] In order to make those skilled in the art better understand the present application scheme, the technical scheme in the present application embodiment will be clearly and completely described below in conjunction with the drawings in the present application embodiment. Obviously, the described embodiment is only a part of the present application embodiment, rather than all the embodiments. The components of the present application embodiment usually described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application for protection, but merely represents the selected embodiment of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0022] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0023] In the interference exposure preparation scheme of large-format gratings, the interference exposure field generated by the interference exposure system is required to be able to expose the entire area of ​​the large-format grating. This is generally achieved by using a mechanical moving device to control the movement of the grating substrate. However, the interference exposure system has stability fluctuations, that is, during the process of exposing the entire area on the large-format grating, the interference exposure field will experience phase drift. During the movement of the grating substrate, there will also be relative posture fluctuations between the grating substrate and the interference exposure field, both of which will affect the final accuracy of preparing the large-format grating.

[0024] See also Figure 1 , Figure 1 The structural block diagram of the grating interference exposure system 100 is shown. The grating interference exposure system 100 at least includes a coherent light generating component 110, a mechanical motion component 140, a posture correction component and a control component 170. The control component 170 is connected to the coherent light generating component 110, the mechanical motion component 140 and the posture correction component 160, and is used to control the mechanical motion component 140 to carry the substrate and the reference grating to move, so that the partial coherent light generated by the coherent light generating component 110 can be converged on different first interference exposure areas of the substrate 1, and is also used to control the posture correction component to correct the posture error between the interference exposure field and the mechanical motion component 140 based on the reference grating interference fringes formed on the reference grating by the partial coherent light generated by the coherent light generating component 110.

[0025] As an embodiment, the grating interference exposure system 100 further includes a phase locking component 150, and the control component 170 is further connected to the phase locking component 150, so that the phase locking component 150 compensates for the phase drift of the interference exposure field based on at least two beams of the coherent light.

[0026] See also Figure 2 , Figure 2 The schematic diagram of the structure of a grating interference exposure system is shown. The grating interference exposure system includes a coherent light generating component, a mechanical motion component 140, a posture correction component, a first interference exposure component 120, a second interference exposure component 130, at least one reference grating 101 and a substrate 102. The substrate 102 is coated with a photosensitive material. The coherent light generating component is used to generate at least two coherent light beams. Part of the at least two coherent light beams pass through the first interference exposure component 120 and converge on the substrate 102 to form an interference exposure field. Part of the at least two coherent light beams pass through the first interference exposure component 120 and the second interference exposure component 130 and converge on the reference grating 101 to form reference grating interference fringes. In particular, for ease of reading, Figure 2 The control component is omitted, but it can be understood that the grating interference exposure system includes a control component, and the control component is connected to the coherent light generating component, the mechanical motion component and the posture correction component.

[0027] The mechanical motion assembly 140 is used to carry the substrate 102 and the reference grating 101, see Figure 3 , Figure 3 A schematic diagram of the combined structure of the mechanical motion component, the substrate and the reference grating is shown, and a Cartesian coordinate system is established with the plane where the mechanical motion component is located as the XY plane. Then, the mechanical motion component 140 can carry the substrate 102 and the reference grating 101 to perform translational motion in the XY plane and rotational motion around the Z axis by receiving the motion control signal of the control component, so that the interference exposure field can expose multiple interference exposure areas on the substrate 102 for multiple times, and finally splice them to form a large-format grating.

[0028] For ease of understanding, the following embodiments are described by taking the coherent light generating component generating two coherent light beams as an example, and the implementation method of generating multiple coherent light beams can be derived based on the following embodiments, rather than limiting the coherent light beams to two beams.

[0029] Exemplarily, the coherent light generating assembly may include a laser 111, a first reflector 112 and a first beam splitter 113. The laser light emitted by the laser 111 is reflected into the first beam splitter 113 after passing through the reflector 112, thereby obtaining a first coherent light beam a and a second coherent light beam b. In particular, the first reflector may be a reflector.

[0030] Specifically, coherent light refers to light with the same vibration direction, frequency and phase difference. Therefore, after the first coherent light beam a and the second coherent light beam b emitted by the coherent light generating component converge on the substrate 102, they can interfere stably to form an interference exposure field, so that the photosensitive material coated on the substrate 102 is exposed to form a grating by the interference exposure field; at the same time, the reference grating 101 is set to make at least one order of diffracted light of each coherent light produce detectable interference fringes, so that after the first coherent light beam a and the second coherent light beam b converge on the reference grating 101, reference grating interference fringes can be generated. For example, see Figure 4 , Figure 4 A schematic diagram of the formation of reference grating interference fringes by coherent light and a reference grating is shown. Taking the case where a coherent light generating component emits two coherent light beams, namely a first coherent light beam a and a second coherent light beam b, as an example, by designing a suitable reference grating period and placement tilt angle, the first coherent light beam a and the second coherent light beam b can be converged on the reference grating 101 to generate multi-order diffraction light. At the same time, the reference grating 101 can make the angle between the M-order diffraction light of the first coherent light beam a and the N-order diffraction light of the second coherent light beam b small enough, so that the light can be combined at a small angle to obtain the reference grating interference fringes 103.

[0031] Specifically, after the first coherent light beam a propagates along the first optical path L1 and passes through the first interference exposure assembly 120, part of the first coherent light beam a is emitted toward the substrate 102, and part of the first coherent light beam a continues to propagate along the third optical path L3 and passes through the second interference exposure assembly 130 before being emitted toward the reference grating 101. After the second coherent light beam b propagates along the second optical path L2 and passes through the first interference exposure assembly 120, part of the first coherent light beam a and the second coherent light beam b continues to propagate along the fourth optical path L4 and passes through the second interference exposure assembly 130 before being emitted toward the reference grating 101. In addition, the part of the first coherent light beam a and the second coherent light beam b emitted toward the substrate 102 generates an interference exposure field on the substrate 102, and the part of the first coherent light beam a and the second coherent light beam b emitted toward the reference grating 101 generates detectable reference grating interference fringes 103 on the reference grating.

[0032] Exemplarily, the first interference exposure component 120 may include a first interference exposure sub-component and a second interference exposure sub-component, each interference exposure sub-component including a beam expander 121, a first collimator 122, and a second reflector 123, the beam expander 121, the first collimator 122, and the second reflector 123 of the first interference exposure sub-component are distributed in sequence along the first optical path L1, and the beam expander 121, the first collimator 122, and the second reflector 123 of the second interference exposure sub-component are distributed in sequence along the second optical path L2. Specifically, the first coherent light beam a passes through the first interference exposure subassembly along the first optical path L1 and is emitted from the coherent light generating assembly 110 to the substrate 102, and the second coherent light beam b passes through the second interference exposure subassembly along the second optical path L2 and is emitted from the coherent light generating assembly 110 to the substrate 102. Furthermore, after the first coherent light beam a is expanded by the beam expander 121 of the first interference exposure subassembly, it is collimated by the first collimator 122 of the first interference exposure subassembly and emitted to the second reflector 123 of the first interference exposure subassembly, and is reflected to the substrate 102 by the second reflector 123. The propagation path of the first coherent light beam b can refer to the propagation path of the first coherent light beam a, and will not be described in detail here. In particular, the first collimator 122 can be a collimator mirror to ensure the periodic consistency of the grating in the exposure field, and the second reflector 123 can be a reflector.

[0033] Exemplarily, the second interference exposure component 130 may include a fifth interference exposure subcomponent and a sixth interference exposure subcomponent, both of which include a beam splitter 131 and a reflector 132. The beam splitter 131 of the fifth interference exposure subcomponent is located at the intersection of the first optical path L1 and the third optical path L3, and is used to lead out a portion of the first coherent light beam so that it passes through the reflector 132 of the fifth interference exposure subcomponent and is incident on the reference grating 101; the beam splitter 131 of the sixth interference exposure subcomponent is located at the intersection of the second optical path L2 and the fourth optical path L4, and is used to lead out a portion of the second coherent light beam so that it passes through the reflector 132 of the sixth interference exposure subcomponent and is incident on the reference grating 101; thereby, a portion of the first coherent light beam and a portion of the second coherent light beam form reference grating interference fringes on the reference grating 101.

[0034] As an implementation, the grating interference exposure system further includes a phase locking component, which is connected to the control component. Exemplarily, the phase locking component may include a second beam splitter 151, a third beam splitter 152, a fourth beam splitter 153, a first sensor 154, and a first active device 155. After the first coherent light beam a and the second coherent light beam b are emitted by the first interference exposure component 120, they are respectively led out by the second beam splitter 151 and the third beam splitter 152 and converged on the fourth beam splitter 153, and after transmission and reflection on the fourth beam splitter 153, they interfere at a small angle to form phase-locked interference fringes. It can be understood that the phase-locked interference fringes are formed by the interference of the first coherent light beam a and the second coherent light beam b on the fourth beam splitter 153. Similarly, the interference exposure field is also formed by the interference of the first coherent light beam a and the second coherent light beam b on the substrate 102. Therefore, the phase stability of the phase-locked interference fringes can reflect the fringe stability of the interference exposure field. Therefore, the fringe drift of the interference exposure field can be corrected by compensating for the fringe drift of the phase-locked interference fringes.

[0035] The first sensor 154 can detect the phase-locked interference fringes formed on the fourth beam splitter 153, and send the phase-locked interference fringes to the control component. The control component calculates the phase drift data of the phase-locked interference fringes to obtain the first control signal. At the same time, the first active device 155 is connected to the control component and the first interference exposure component 120, and is used to receive the first control signal of the control component 170. The first control signal is used to control the displacement of the first active device 155. The control component 170 causes the first interference exposure component 120 to generate a certain displacement based on the fringe drift of the phase-locked interference fringes to modulate the phase of the phase-locked interference fringes, thereby correcting the phase drift. Exemplarily, the first active device 155 can be a micro brake, and is connected to the second reflector 123 of the second interference exposure subassembly. The first active device 155 can drive the second reflector 123 to generate displacement in the normal direction of the mirror surface, thereby modulating the phase of the phase-locked interference fringes. Combined with the closed-loop control algorithm, the phase drift of the phase-locked interference fringes can be compensated by the movement of the second reflector 123, thereby ensuring the phase stability of the interference exposure field.

[0036] Exemplarily, the posture correction component may include a second sensor 161 and a second active device 162. The second sensor 161 can detect reference grating interference fringes and send the reference grating interference fringes to the control component 170. The control component calculates the posture error data between the mechanical motion system 140 and the interference exposure field based on the reference grating interference fringes 103 and obtains a second control signal. The second active device 162 is used to receive the second control signal sent by the control component to compensate for the above-mentioned posture error. It can be understood that the second active device 162 can compensate for the posture error by causing the mechanical motion system 140 to produce a displacement, or by causing the first interference exposure component 120 to produce a displacement to compensate for the posture error.

[0037] Specifically, see Figure 5 , Figure 5 Schematic diagram showing the variation of the reference grating interference fringes 103, wherein: Figure 5 (a) is the reference grating interference fringe under the condition of no posture error, which can be regarded as the reference grating reference fringe. When the mechanical motion component 140 and the interference exposure field produce posture error around the Y axis, the inclination of the reference grating interference fringe will change, such as Figure 5 As shown in (b), when the mechanical motion component 140 and the interference exposure field produce a posture error around the Z axis, the period of the reference grating interference fringes will change, such as Figure 5 Therefore, the reference grating interference fringes can be detected by the second sensor 161 and uploaded to the control component, which solves the inclination and period value of the reference grating interference fringes and thereby calculates the posture error data between the mechanical motion component 140 and the interference exposure field, and sends a second control signal to the second active device 162 based on the error data, so that the second active device 162 drives the mechanical motion system 140 to generate displacement, or drives the first interference exposure component 120 to generate displacement, that is, the interference exposure field generates displacement to compensate for the posture error.

[0038] For example, see Figure 6 , Figure 6 A structural schematic diagram of the second active device 162 is shown. The second active device 162 can be a micro brake and is connected to the beam expander 121 of the first interference exposure assembly 120. When the second sensor 161 calculates that the mechanical motion assembly 140 and the interference exposure field have a posture error caused by the posture fluctuation rotating around the Y axis, the beam expander 121 is driven to move along the Y axis direction, thereby modulating the normal vector direction of the interference fringes of the interference exposure field to compensate for the posture error; when the second sensor 161 calculates that the mechanical motion assembly 140 and the interference exposure field have a posture error caused by the posture fluctuation rotating around the Z axis, the beam expander 121 is driven to move in a direction perpendicular to the Y axis and perpendicular to the main optical axis of the beam expander, thereby modulating the interference fringes period of the interference exposure field to compensate for the posture error.

[0039] For example, see Figure 7 , Figure 7Another structural schematic diagram of the second active device 162 is shown. It is worth noting that the Cartesian coordinate system is still established here with the plane where the mechanical motion component 140 is located as the XY plane, so it can be regarded as the same coordinate system used in the above embodiment. Specifically, the second active device 162 can be a precision control console, and is connected to the mechanical motion component 140, and the precision deflection table can achieve small-angle precision motion around the Y axis and around the Z axis, so as to modulate the relative posture of the mechanical motion system 140 and the interference exposure field by changing the displacement of the mechanical motion component to compensate for the posture error.

[0040] For example, see Figure 8 , Figure 8 The schematic diagram of the structure of the grating interference exposure system using another first interference exposure component 120 is shown, wherein the first interference exposure component 120 may include a third interference exposure sub-component and a fourth interference exposure sub-component, each interference exposure sub-component includes an optical fiber 125, a first optical fiber collimation coupler 124, a second optical fiber collimation coupler 126 and a second collimator 127, the first optical fiber collimation coupler 124, the optical fiber 125, the second optical fiber collimation coupler 126 and the second collimator 127 of the third interference exposure sub-component are sequentially distributed along the first optical path L1, and the first optical fiber collimation coupler 124, the optical fiber 125, the second optical fiber collimation coupler 126 and the second collimator 127 of the fourth interference exposure sub-component are sequentially distributed along the second optical path L2. Specifically, the first coherent light beam a is emitted from the coherent light generating assembly 110 to the substrate 102 along the first optical path L1 through the third interference exposure subassembly, and the second coherent light beam b is emitted from the coherent light generating assembly 110 to the substrate 102 along the second optical path L2 through the fourth interference exposure subassembly. Further, the first coherent light beam a is coupled into the first optical fiber collimating coupler 124 of the first interference exposure subassembly and is transmitted through the optical fiber 125 and then output from the second optical fiber collimating coupler 126, and then collimated by the second collimator 127 and emitted to the substrate 102. The propagation path of the first coherent light beam b can refer to the propagation path of the first coherent light beam a, and will not be described in detail here. In particular, the second collimator 127 can be a collimating mirror to ensure the periodic consistency of the grating in the exposure field. Furthermore, the first active device 155 of the phase locking component 150 can be an acousto-optic modulator, which adjusts the frequency difference between the first coherent light beam a and the second coherent light beam b by adjusting the frequency of the second coherent light beam b, thereby achieving the purpose of modulating the phase of the interference exposure field fringes; the second active device 162 of the posture correction component 160 can be a micro-brake, and is connected to the second fiber collimation coupler 126 of the first interference exposure component 120, and controls the micro-motion of the second fiber collimation coupler 126 to achieve the purpose of modulating the relative posture of the mechanical motion system 140 and the interference exposure field, thereby compensating for the posture error. In particular, for ease of reading, Figure 8The second interference exposure component, the posture correction component, the phase locking component and the control component are omitted, but it can be understood that Figure 8 The grating interference exposure system shown may also include the above components, and related implementations may refer to the above embodiments.

[0041] In this embodiment, the use of optical fiber to transmit coherent light avoids the optical component assembly, alignment and maintenance requirements of free-space double-beam interference in the first embodiment.

[0042] Exemplarily, the control component is used to control the posture correction component to receive stripes, solve errors, receive posture fluctuation data and drive the second active device to move based on the posture fluctuation data, and also to control the phase locking component to receive stripe information, solve the displacement value of the phase locked piezoelectric device, receive stripe drift data and drive the first active device to move based on the stripe drift data, and also to plan the trajectory of the mechanical motion component and drive the mechanical motion component to move, and also to control the opening and closing of the coherent light generating component. In particular, the control component can be one or more processors, which can be implemented in at least one hardware form of digital signal processing (DSP), field programmable gate array (FPGA), and programmable logic array (PLA). The processor 602 can integrate one or a combination of a central processing unit (CPU), a data processor (DPU), and a modem.

[0043] Therefore, the grating interference exposure system provided in the present application includes a coherent light generating component, a first interference exposure component, a second interference exposure component, a mechanical motion component, a phase locking component, a posture correction component, a control component, at least one reference grating and a substrate, wherein the substrate and at least one reference grating are spaced apart on the mechanical motion component, and the substrate is coated with a photosensitive material. In the system, at least two coherent light beams generated by a coherent light generating component are converged on a substrate through a first interference exposure component to form a first interference exposure field, and are converged on a reference grating through the first interference exposure component and the second interference exposure component to form a second interference exposure field. The posture correction component corrects the posture error between the first interference exposure field and the mechanical motion system during the splicing exposure process based on the second interference exposure field. The present application performs posture correction by additionally leading the coherent light used for exposure to the outside of the exposure area to be exposed, i.e., on the reference grating, to ensure that in the process in which the mechanical motion component drives the substrate to move so that the interference exposure field generated by the coherent light exposes the entire substrate, the additional coherent light led out can always form reference grating interference fringes on the reference grating at the same time, thereby avoiding the use of the original coherent light in the traditional splicing exposure to form reference grating interference fringes on the reference grating for posture correction. There may be a problem in which the coherent light cannot be directed to the reference grating during the movement of the mechanical motion component, i.e., the reference grating interference fringes cannot be generated. This breaks through the limitation of one-dimensional splicing of traditional splicing exposure, and can realize the posture correction of the interference exposure system under any number of two-dimensional splicing, thereby preparing high-precision large-format gratings.

[0044] See also Fig. 9 , Fig. 9 A method flow chart of a grating interference exposure method is shown, comprising:

[0045] S110: Start the coherent light generating component to generate at least two coherent light beams, the at least two coherent light beams pass through the first interference exposure component to form an interference exposure field, and the at least two coherent light beams pass through the first interference exposure component and the second exposure component to generate reference grating interference fringes.

[0046] S120: Control the phase locking component to compensate for the phase drift of the interference exposure field based on at least two beams of the coherent light.

[0047] The specific implementation of step S110 to step S120 may refer to the above-mentioned embodiment of the grating interference exposure system, which will not be described in detail here.

[0048] S130: Control the movement of the mechanical motion component to, while exposing multiple interference exposure areas on the substrate, control the posture correction component to correct the posture error between the interference exposure field and the mechanical motion system based on the reference grating interference fringes.

[0049] As an implementation, see Fig.10 , Fig.10 A schematic diagram of the positions of the substrate and the reference grating on the mechanical motion component during the interference exposure process is shown, wherein the substrate 102 has a plurality of first interference exposure areas S101, S102, S103 and S104, and the reference grating 101 has a plurality of second interference exposure areas S201, S202, S203 and S204, and the second interference exposure areas correspond to the first interference exposure areas one by one. While exposing the plurality of interference exposure areas on the substrate, the method of controlling the posture correction component to correct the posture error between the interference exposure field and the mechanical motion system based on the reference grating interference fringes may be:

[0050] After the coherent light beam generates an interference exposure field on the substrate and the phase locking component ensures that the phase of the interference exposure field is stable, the mechanical motion component carries the substrate to move, so that the first interference exposure area exposed on the substrate by the interference exposure field is S101. At this time, the corresponding second interference exposure area on the reference grating is S201. The posture correction component records the reference grating interference fringes at this time through the sensor as the reference grating reference interference fringes, and during the continuous exposure of the first interference exposure area S101, the posture correction system collects the current reference grating interference fringes in real time as the reference grating real-time interference fringes, and then, the reference grating real-time interference fringes are compared with the reference grating reference interference fringes in real time, and the relative posture error between the current mechanical motion system and the interference exposure field is solved, and the second active device is controlled to make the beam expander or the mechanical motion component move slightly, so as to correct the relative posture error between the mechanical motion system and the interference exposure field. After the first interference exposure area S101 is exposed, the mechanical motion system carries the substrate to move, so that the first interference exposure area exposed by the interference exposure field is S102. At this time, the corresponding second interference exposure area on the reference grating is S202. During the exposure of the first interference exposure area S102, the posture correction system collects the current reference grating interference fringes in real time as the reference grating real-time interference fringes, and then compares the reference grating real-time interference fringes with the reference grating reference interference fringes in real time, solves the relative posture error between the current mechanical motion system and the interference exposure field, and controls the second active device to make the beam expander or the mechanical motion component move slightly, so as to correct the relative posture error between the mechanical motion system and the interference exposure field.

[0051] In another embodiment, the reference grating reference interference fringes may also be preset values, and the relative posture error between the current mechanical motion and the interference exposure field is solved by comparing the real-time interference fringes of the reference grating with the preset reference grating reference interference fringes.

[0052] Similarly, after the first interference exposure area S102 is exposed, the first interference exposure area S103 and the first interference exposure area S104 are exposed in sequence. During the exposure, the reference grating reference interference fringes recorded by the posture correction component when the exposure area is the first interference exposure area S102 are used as a reference to solve the current posture error and compensate until all areas are exposed. This ensures the periodic consistency accuracy and deflection accuracy of the prepared large-format grating.

[0053] As an implementation, see Fig.11 , Fig.11 Another schematic diagram of the positions of the substrate and the reference grating on the mechanical motion component during the interference exposure process is shown. In this case, there are multiple reference gratings 1011, 1012 and 1013, which are simultaneously arranged on the mechanical motion component. The substrate 102 has multiple first interference exposure areas S101, S102, S103, S104, S105, S106, S107 and S108, and the mechanical motion component has multiple second interference exposure areas S201, S202, S203, S204, S205, S206, S207 and S208. The second interference exposure areas correspond to the first interference exposure areas one by one, and any one of the second interference exposure areas covers the same reference grating as at least one of the other second interference exposure areas. While exposing the multiple interference exposure areas on the substrate, the method of controlling the posture correction component to correct the posture error between the interference exposure field and the mechanical motion system based on the reference grating interference fringes can be:

[0054] After the coherent light beam generates an interference exposure field on the substrate and the phase locking component ensures the phase stability of the interference exposure field, the mechanical motion component carries the substrate to move, so that the first interference exposure area exposed by the interference exposure field on the substrate is S101. At this time, the area corresponding to the second interference exposure area covered on the reference grating 1011 is S201. The posture correction component records the reference grating interference fringes on the reference grating 1011 at this time through the sensor as the first reference grating reference interference fringes.

[0055] During the continuous exposure of the first interference exposure area S101, the first interference exposure area S102, and the first interference exposure area S103, that is, during the exposure of all the first interference exposure areas that share the same reference grating 1011 with the first interference exposure area S101, the posture correction system collects the current reference grating interference fringes in real time as the reference grating real-time interference fringes, and then compares the reference grating real-time interference fringes with the first reference grating reference interference fringes in real time to calculate the relative posture error between the current mechanical motion system and the interference exposure field, and at the same time controls the second active device to cause the beam expander or the mechanical motion component to move slightly, thereby correcting the relative posture error between the mechanical motion system and the interference exposure field.

[0056] In another embodiment, the first reference grating reference interference fringes may also be a preset value, by comparing the real-time interference fringes of the reference grating with the preset first reference grating reference interference fringes to solve the relative posture error between the current mechanical motion and the interference exposure field, and at the same time control the second active device to make the beam expander or the mechanical motion component move slightly, thereby correcting the relative posture error between the mechanical motion system and the interference exposure field.

[0057] During the exposure of the first interference exposure area S103, the posture correction component records the reference grating interference fringes formed by the second interference exposure area S203 and the reference grating 1012, and records the above fringes as second reference grating reference interference fringes.

[0058] During the first interference exposure area S104, the first interference exposure area S105, and the first interference exposure area S109, the second reference grating reference interference fringes are used as a reference, and the posture correction system collects the current reference grating interference fringes in real time as the reference grating real-time interference fringes, and then compares the reference grating real-time interference fringes with the second reference grating reference interference fringes in real time to solve the relative posture error between the current mechanical motion system and the interference exposure field, and at the same time controls the second active device to make the beam expander or the mechanical motion component move slightly, so as to correct the relative posture error between the mechanical motion system and the interference exposure field.

[0059] During the exposure of the first interference exposure area S105, the posture correction component records the reference grating interference fringes formed by the second interference exposure area S205 and the reference grating 1013, and records the above fringes as third reference grating reference interference fringes.

[0060] During the first interference exposure area S106, the first interference exposure area S107, and the first interference exposure area S108, the third reference grating reference interference fringes are used as a reference, and the posture correction system collects the current reference grating interference fringes in real time as the reference grating real-time interference fringes, and then compares the reference grating real-time interference fringes with the third reference grating reference interference fringes in real time to solve the relative posture error between the current mechanical motion system and the interference exposure field, and at the same time controls the second active device to make the beam expander or the mechanical motion component move slightly, so as to correct the relative posture error between the mechanical motion system and the interference exposure field.

[0061] In another embodiment, the second reference grating reference interference fringes may also be a preset value. The real-time interference fringes of the reference grating are compared with the preset second reference grating reference interference fringes to solve the relative posture error between the current mechanical motion and the interference exposure field. At the same time, the second active device is controlled to cause the beam expander or the mechanical motion component to move slightly, thereby correcting the relative posture error between the mechanical motion system and the interference exposure field.

[0062] Therefore, by setting multiple reference gratings and using the same reference grating interference fringes for the second interference exposure area covered by the same reference grating, the periodic consistency accuracy and the deflection angle accuracy of each exposure area of ​​the prepared large-format grating are guaranteed.

[0063] Therefore, the grating interference exposure method provided in the present application is applied to the grating interference exposure system in the above-mentioned embodiment, including: starting the coherent light generating component to generate at least two beams of coherent light, at least two beams of the coherent light pass through the first interference exposure component to form an interference exposure field, and at least two beams of the coherent light pass through the first interference exposure component and the second exposure component to generate reference grating interference fringes; controlling the phase locking component to compensate for the phase drift of the interference exposure field based on at least two beams of the coherent light; controlling the movement of the mechanical motion component, while exposing multiple first interference exposure areas on the substrate, controlling the posture correction component to correct the posture error between the interference exposure field and the mechanical motion system based on the reference grating interference fringes. The coherent light used for exposure is additionally led out to the outside of the exposure area to be exposed, that is, on the reference grating, and reference grating reference interference fringes are set. The reference grating interference fringes and the reference grating reference interference fringes are obtained in real time during the exposure process, so as to perform posture correction, thereby ensuring the periodic consistency accuracy and the angular accuracy of each exposure area of ​​the prepared large-format grating, and ensuring that in the process of the mechanical motion component driving the substrate to move so that the interference exposure field generated by the coherent light exposes the entire substrate, the additional coherent light led out can always form reference grating interference fringes on the reference grating at the same time, thereby avoiding the use of the original coherent light in the traditional splicing exposure to form reference grating interference fringes on the reference grating for posture correction, and the problem that the coherent light cannot be directed to the reference grating, that is, the reference grating interference fringes cannot be generated during the movement of the mechanical motion component. The limitation of one-dimensional splicing of traditional splicing exposure has been broken through, and the posture correction of the interference exposure system under any number of two-dimensional splicing can be realized, thereby preparing high-precision large-format gratings.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A grating interference exposure system, characterized in that: The invention comprises a coherent light generating component, a first interference exposure component, a second interference exposure component, a mechanical motion component, a posture correction component, a control component, at least one reference grating and a substrate, wherein the substrate and at least one reference grating are arranged on the mechanical motion component at intervals, and the substrate is coated with a photosensitive material; Wherein, the coherent light generating component is used to generate at least two coherent light beams, and the at least two coherent light beams are converged on the substrate through the first interference exposure component to form an interference exposure field; Part of the coherent light passes through the first interference exposure component and the second interference exposure component and converges on the reference grating to generate reference grating interference fringes; The control component is connected to the coherent light generating component, the mechanical motion component and the posture correction component, and the control component is used to control the movement of the mechanical motion component to move the substrate and the reference grating carried on the mechanical motion component, so that at least two beams of the coherent light can converge on different first interference exposure areas of the substrate; The control component is also used to control the posture correction component to correct the posture error between the interference exposure field and the mechanical motion component based on the reference grating interference fringes.

2. The system according to claim 1 further comprises a phase locking component, which is located between the coherent light generating component and the mechanical motion component, and is used to compensate for the phase drift of the interference exposure field based on at least two beams of the coherent light.

3. The system according to claim 1, characterized in that The coherent light generating component emits a first coherent light beam and a second coherent light beam. After the first coherent light beam propagates along the first optical path through the first interference exposure component, part of the first coherent light beam is emitted toward the substrate, and part of the first coherent light beam propagates along the third optical path through the second interference exposure component and then is emitted toward the reference grating. After the second coherent light beam propagates along the second optical path through the first interference exposure component, part of the first coherent light beam is emitted toward the substrate, and part of the second coherent light beam propagates along the fourth optical path through the second interference exposure component and then is emitted toward the reference grating.

4. The system according to claim 3, characterized in that The first interference exposure assembly includes a first interference exposure subassembly and a second interference exposure subassembly, and the first interference exposure subassembly and the second interference exposure subassembly both include a beam expander, a first collimator and a second reflector; Among them, the beam expander, the first collimator and the second reflector of the first interference exposure subassembly are distributed in sequence along the first optical path, and the beam expander, the first collimator and the second reflector of the second interference exposure subassembly are distributed in sequence along the second optical path.

5. The system according to claim 3, characterized in that The first interference exposure component includes a third interference exposure sub-component and a fourth interference exposure sub-component, and the third interference exposure sub-component and the fourth interference exposure sub-component each include an optical fiber, a first optical fiber collimation coupler, a second optical fiber collimation coupler, and a second collimator; Among them, the first fiber collimation coupler, optical fiber, second fiber collimation coupler and second collimator of the third interference exposure sub-assembly are distributed in sequence along the first optical path, and the first fiber collimation coupler, optical fiber, second fiber collimation coupler and second collimator of the fourth interference exposure sub-assembly are distributed in sequence along the second optical path.

6. The system according to claim 3, characterized in that The phase locking component includes a second beam splitter, a third beam splitter, a fourth beam splitter, a first sensor and a first active device, part of the first coherent light beam is led out from the first optical path through the second beam splitter and propagates to the fourth beam splitter, part of the second coherent light beam is led out from the second optical path through the third beam splitter and propagates to the fourth beam splitter, and the first sensor is used to detect the phase-locked interference fringes formed by the first coherent light beam and the second coherent light beam on the fourth beam splitter and send them to the control component; The control component is used to calculate the phase drift based on the phase-locked interference fringes, and send a first control signal to the first active device based on the phase drift; The first active device is used to correct the phase drift based on the received first control signal.

7. The system according to claim 3, characterized in that The second interference exposure assembly includes a fifth interference exposure subassembly and a sixth interference exposure subassembly, and the fifth interference exposure subassembly and the sixth interference exposure subassembly each include a beam splitter and a reflector; The beam splitter of the fifth interference exposure subassembly is located at the intersection of the first optical path and the third optical path, and is used to lead out a portion of the first coherent light beam, and the portion of the first coherent light beam is incident on the reference grating through the reflector of the fifth interference exposure subassembly; The beam splitter of the sixth interference exposure subassembly is located at the intersection of the second optical path and the fourth optical path, and is used to lead out a portion of the second coherent light beam, and the portion of the second coherent light beam is incident on the reference grating through the reflector of the sixth interference exposure subassembly; The portion of the first coherent light beam incident on the reference grating interferes with the portion of the second coherent light beam to form reference grating interference fringes.

8. The system according to claim 3, characterized in that The posture correction component includes a second sensor and a second active device, wherein the second sensor is used to detect the reference grating stripes and send the reference grating stripes to the control component; The control component is used to calculate the fringe deviation based on the reference grating fringe, and send a second control signal to the second active device based on the fringe deviation; The second active device is used to correct the posture error between the interference exposure field and the mechanical motion system based on the received second control signal.

9. The system according to claim 7, characterized in that The mechanical motion component also has multiple second interference exposure areas, part of the first coherent light beam drawn out by the beam splitter of the fifth interference exposure sub-component and part of the second coherent light beam drawn out by the beam splitter of the sixth interference exposure sub-component are incident on the second interference exposure areas, and the second interference exposure areas correspond one-to-one to the first interference exposure areas. The system also satisfies: any one of the second interference exposure areas covers the same reference grating as at least one of the other second interference exposure areas.

10. A grating interference exposure method, characterized in that: The grating interference exposure system according to any one of claims 1 to 9, wherein the method comprises: The coherent light generating component is started to generate at least two coherent light beams, part of the at least two coherent light beams pass through the first interference exposure component to form an interference exposure field, and part of the at least two coherent light beams pass through the first interference exposure component and the second exposure component to be incident on the reference grating to generate reference grating interference fringes; Controlling the phase locking component to compensate for the phase drift of the interference exposure field based on at least two beams of the coherent light; The movement of the mechanical motion component is controlled to, while exposing a plurality of first interference exposure areas on the substrate, control the posture correction component to correct the posture error between the interference exposure field and the mechanical motion system based on the reference grating interference fringes.

11. The method according to claim 10, characterized in that The controlling the movement of the mechanical motion component, while the interference exposure field exposes a plurality of interference exposure areas on the substrate, controlling the posture correction component to correct the posture error between the interference exposure field and the mechanical motion system based on the reference grating interference fringes, comprises: The posture correction component obtains the reference grating interference fringes at a specified time as reference grating reference interference fringes; When the interference exposure field exposes the plurality of first interference exposure areas on the substrate, the posture correction component obtains the reference grating interference fringes at this time as reference grating real-time interference fringes; The posture correction component is controlled to calculate and correct the posture error between the first interference exposure field and the mechanical motion system based on the reference grating real-time interference fringes and the reference grating reference interference fringes.

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