阅读说明：本技术 大面积纳米光刻系统及其方法 (Large-area nano photoetching system and method thereof ) 是由 浦东林 陈林森 朱鹏飞 朱鸣 邵仁锦 于 2019-01-10 设计创作，主要内容包括：一种大面积纳米光刻系统,包括工件台、位置反馈系统、干涉光学系统和控制系统,工件台上设有待光刻的光刻基片；位置反馈系统用于测量和计算工件台的误差；干涉光学系统用于产生干涉曝光场,对光刻基片进行干涉光刻,干涉光学系统包括衍射光学器件；控制系统分别与该工件台、该位置反馈系统和该干涉光学系统电性连接；该控制系统控制该衍射光学器件的运动,用以补偿该工件台的误差。本发明的大面积纳米光刻系统能达到大面积纳米结构高精度制备。本发明还涉及一种大面积纳米光刻方法。(A large-area nano photoetching system comprises a workpiece table, a position feedback system, an interference optical system and a control system, wherein a photoetching substrate to be photoetched is arranged on the workpiece table; the position feedback system is used for measuring and calculating the error of the workpiece table; the interference optical system is used for generating an interference exposure field and carrying out interference photoetching on the photoetching substrate and comprises a diffraction optical device; the control system is electrically connected with the workpiece table, the position feedback system and the interference optical system respectively; the control system controls movement of the diffractive optical element to compensate for errors in the stage. The large-area nano photoetching system can achieve high-precision preparation of large-area nano structures. The invention also relates to a large-area nano-photoetching method.)

1. A large-area nano lithography system is characterized by comprising a workpiece stage, a position feedback system, an interference optical system and a control system, wherein:

a photoetching substrate to be photoetched is arranged on the workpiece table;

the position feedback system is used for measuring and calculating the error of the workpiece platform;

the interference optical system is used for generating an interference exposure field and carrying out interference photoetching on the photoetching substrate, and the interference optical system comprises a diffraction optical device;

the control system is electrically connected with the workpiece table, the position feedback system and the interference optical system respectively; the control system controls movement of the diffractive optical element to compensate for errors in the stage.

2. The large area nanolithography system according to claim 1, wherein the stage errors include coordinate positioning errors, heading angle errors, yaw angle errors and pitch angle errors, the control system controlling the diffractive optical element to translate along the vertical optical axis to compensate for the stage coordinate positioning errors; the control system controls the diffraction optical device to rotate around the optical axis so as to compensate the course angle error of the workpiece table; the control system controls the diffractive optical element to move along the direction of the optical axis so as to compensate for errors in the yaw angle and/or pitch angle of the workpiece table.

3. The large area nanolithography system according to claim 2, wherein the position feedback system comprises a light source, an image capturing module, a reference grating and a two-dimensional grating, the reference grating is disposed on the stage, the reference grating is fixed to the lithography substrate, the two-dimensional grating is disposed above the reference grating, the light source illuminates to form a recognizable moire pattern between the two-dimensional grating and the reference grating, the image capturing module recognizes the moire pattern, and the variation of the moire pattern is quantitatively analyzed to calculate the error of the stage.

4. The large area nanolithography system according to claim 3, wherein the position feedback system further comprises a plurality of first lenses and a first beam splitter, the image capture module is disposed above the two-dimensional grating, the plurality of first lenses are disposed between the image capture module and the two-dimensional grating, the first beam splitter is disposed between the plurality of first lenses, the light source is disposed at one side of the first beam splitter, and light emitted from the light source is directed to the two-dimensional grating and the reference grating through the first beam splitter.

5. The large area nanolithography system according to claim 2, wherein the position feedback system comprises a first laser, a first interferometry module, a second interferometry module and a plurality of transflective mirrors, the first laser provides a laser source for the first interferometry module and the second interferometry module through the transflective mirrors, the first interferometry module and the second interferometry module are disposed around the stage, the control system is electrically connected to the first laser, the first interferometry module and the second interferometry module respectively, and the control system calculates a coordinate positioning error, a course angle error, a yaw angle error and a pitch angle error of the stage according to the differential interferometry path; defining the width direction of the workpiece table as a first direction, and defining the length direction of the workpiece table as a second direction, wherein the first direction is vertical to the second direction; the first interferometric measuring module emits a measurement optical path along a first direction, and the second interferometric measuring module emits a measurement optical path along a second direction.

6. The large area nanolithography system according to any one of claims 1 to 5, wherein the interference optics further comprises a second laser, a second lens, a third lens, a second beam splitter and a miniature objective lens, the second lens and the third lens form a 4F imaging system, the diffractive optical device is disposed between the second lens and the third lens, the laser emitted from the second laser sequentially passes through the second lens, the diffractive optical device, the third lens, the second beam splitter and the miniature objective lens, and forms an interference exposure field on the lithography substrate.

7. The large area nanolithography system according to claim 6, wherein the interference optics system further comprises a beam shaper disposed between the second laser and the second lens and a detection optical path disposed in the transmission optical path of the second beam splitter.

8. A large area nanolithography method using the large area nanolithography system according to any one of claims 1 to 7, the method comprising:

providing a workpiece table, and arranging a photoetching substrate to be photoetched on the workpiece table;

providing a position feedback system, and measuring and calculating the error of the workpiece platform by using the position feedback system;

providing an interference optical system, and performing interference lithography on the lithography substrate by using the interference optical system, wherein the interference optical system comprises a diffraction optical device; and

providing a control system which is respectively electrically connected with the workpiece table, the position feedback system and the interference optical system; the control system is used to control the movement of the diffractive optical element to compensate for errors in the stage.

9. The large area nanolithography method according to claim 8, wherein the stage errors include coordinate positioning errors, heading angle errors, yaw angle errors and pitch angle errors, and the control system controls the diffractive optical element to translate along a direction perpendicular to the optical axis to compensate for the stage coordinate positioning errors; controlling the diffraction optical device to rotate around the optical axis by using the control system so as to compensate the course angle error of the workpiece table; and controlling the diffractive optical device to move along the direction of the optical axis by using the control system so as to compensate the errors of the yaw angle and/or the pitch angle of the workpiece table.

10. The large area nanolithography method according to claim 9, wherein a reference grating is disposed on the stage, the reference grating is fixedly disposed on the lithography substrate, and a two-dimensional grating is disposed above the reference grating;

forming a recognizable moire pattern between the two-dimensional grating and the reference grating by using light source irradiation;

and identifying the Moire pattern by using an image acquisition module, and quantitatively analyzing the change of the Moire pattern to calculate the coordinate positioning error, the course angle error, the yaw angle error and the pitch angle error of the workpiece table.

11. The large area nanolithography method according to claim 9, wherein the first interferometry module and the second interferometry module are disposed around the stage, and the coordinate positioning error, the heading angle error, the yaw angle error and the pitch angle error of the stage are calculated by the control system according to the differential interferometry path.

Technical Field

The invention relates to the technical field of interference lithography, in particular to a large-area nano lithography system and a method thereof.

Background

Nanostructures (nanostructures) generally refer to minute structures with dimensions below 100nm, and more broadly to structures with dimensions below 500 nm. The current technical means of the graphical preparation of the nano structure mainly comprises the following steps:

electron beam direct writing: the method is a nano patterning processing technology with high resolution and high flexibility, generally, under the condition of scientific research, the controllable patterning preparation of a nano structure firstly adopts electron beam direct writing lithography, however, the current two types of electron beam direct writing equipment and high-resolution Gaussian beam direct writing equipment need preparation time of hours under the area of millimeter breadth, and the application capability of actual materials/devices is poor; the high-energy deformable beam direct writing equipment is mainly applied to preparation of semiconductor masks at present, the breadth is 6-8 inches, and the micrometer structure graph needs hours in preparation, and the nanostructure direct writing is still a difficult problem for deformable beams.

The semiconductor alignment technology comprises the following steps: at present, the semiconductor photoetching reaches the technical node of 10nm level on a silicon chip through Double Pattern, PSM, photoresist nonlinearity and other technologies, however, the high resolution is reflected on the characteristics of a key layer and cannot be well matched with the dense structural characteristic requirements of nano materials/devices, in addition, the semiconductor overlay technology needs a mask as a Pattern template, and the matching technologies of Pattern design, data processing and the like are optimized for a semiconductor and only support the breadth of 8-12 inches.

Holographic interference lithography: the method is a convenient means for realizing a regular micro-nano structure, the traditional holographic interference utilizes conditions such as an optical platform, a laser, a low aberration collimating optical system and the like to form a micro-nano structure with a large area on a photosensitive material through one or more times of cross exposure, the structure is a periodic or chirped structure generally, the designability of the structure is low, and the method can be applied to certain specific fields such as DFB lasers and the like. The digital holographic interference technology is an interference lithography technology combining computer graphic processing and precise control, a series of key technologies are accumulated in the field of Suzhou university and Suda Viger in China, the scanning interference lithography technology is also developed by the U.S. MIT, the digital holographic interference technology tries to break through the problems of single graph and limited breadth of the traditional holographic interference, and the splicing precision between optical fields caused by the digital technology is a key problem of limited application.

Other nano-processing technologies, such as Focused Ion Beam (FIB), direct probe writing (SP L), etc., have low processing efficiency, and can only perform patterned processing in a micro area, such as self-assembly technology, which utilizes weak forces among a plurality of atoms, ions, and molecules, and simultaneously, spontaneously associates and integrates to form a compact and ordered whole, and has the limitation that the designability of the structure is poor, and the technology cannot become a general nano-processing technology.

In conclusion, no solution with better applicability exists for high-precision graphical preparation of large-area nano structures, and the digital holographic interference lithography technology has great application value if the problems of micro-area regulation and high-precision splicing of the structures can be effectively solved.

Disclosure of Invention

In view of the above, the present invention provides a large-area nano lithography system, which can realize high-progress splicing between interference light fields, and achieve the purpose of high-precision preparation of large-area nano structures.

A large-area nano photoetching system comprises a workpiece table, a position feedback system, an interference optical system and a control system, wherein a photoetching substrate to be photoetched is arranged on the workpiece table; the position feedback system is used for measuring and calculating the error of the workpiece table; the interference optical system is used for generating an interference exposure field and carrying out interference photoetching on the photoetching substrate and comprises a diffraction optical device; the control system is electrically connected with the workpiece table, the position feedback system and the interference optical system respectively; the control system controls movement of the diffractive optical element to compensate for errors in the stage.

In the embodiment of the invention, the errors of the workpiece table comprise coordinate positioning errors, course angle errors, yaw angle errors and pitch angle errors, and the control system controls the diffractive optical element to translate along the direction vertical to the optical axis so as to compensate the coordinate positioning errors of the workpiece table; the control system controls the diffraction optical device to rotate around the optical axis so as to compensate the course angle error of the workpiece table; the control system controls the diffractive optical element to move along the direction of the optical axis so as to compensate for errors in the yaw angle and/or pitch angle of the workpiece table.

In an embodiment of the present invention, the position feedback system includes a light source, an image obtaining module, a reference grating and a two-dimensional grating, the reference grating is disposed on the stage, the reference grating is fixedly disposed on the lithographic substrate, the two-dimensional grating is disposed above the reference grating, the light source illuminates the two-dimensional grating and the reference grating to form a recognizable moire pattern therebetween, the image obtaining module identifies the moire pattern, and performs a quantitative analysis on a change of the moire pattern to calculate an error of the stage.

In an embodiment of the invention, the position feedback system further includes a plurality of first lenses and a first beam splitter, the image acquisition module is disposed above the two-dimensional grating, the plurality of first lenses are disposed between the image acquisition module and the two-dimensional grating, the first beam splitter is disposed between the first lenses, the light source is disposed on one side of the first beam splitter, and light emitted by the light source is emitted to the two-dimensional grating and the reference grating through the first beam splitter.

In an embodiment of the present invention, the position feedback system includes a first laser, a first interference measurement module, a second interference measurement module, and a plurality of semi-transparent and semi-reflective mirrors, the first laser provides a laser source for the first interference measurement module and the second interference measurement module through the plurality of semi-transparent and semi-reflective mirrors, the first interference measurement module and the second interference measurement module are disposed on the periphery of the workpiece stage, the control system is electrically connected to the first laser, the first interference measurement module, and the second interference measurement module, respectively, and the control system calculates a coordinate positioning error, a course angle error, a yaw angle error, and a pitch angle error of the workpiece stage according to a differential interference measurement optical path; defining the width direction of the workpiece table as a first direction, and defining the length direction of the workpiece table as a second direction, wherein the first direction is vertical to the second direction; the first interferometric measuring module emits a measurement optical path along a first direction, and the second interferometric measuring module emits a measurement optical path along a second direction.

In an embodiment of the present invention, the interference optical system further includes a second laser, a second lens, a third lens, a second beam splitter and a micro objective, the second lens and the third lens form a 4F imaging system, the diffractive optical device is disposed between the second lens and the third lens, and laser light emitted by the second laser sequentially passes through the second lens, the diffractive optical device, the third lens, the second beam splitter and the micro objective, and forms an interference exposure field on the lithography substrate.

In an embodiment of the present invention, the interference optical system further includes a beam shaper disposed between the second laser and the second lens, and a detection optical path disposed on the transmission optical path of the second beam splitter.

The invention also provides a large-area nano-lithography method using the large-area nano-lithography system, comprising:

providing a workpiece table, and arranging a photoetching substrate to be photoetched on the workpiece table;

providing a position feedback system, and measuring and calculating the error of the workpiece platform by using the position feedback system;

providing an interference optical system, and performing interference lithography on the lithography substrate by using the interference optical system, wherein the interference optical system comprises a diffraction optical device; and

providing a control system which is respectively electrically connected with the workpiece table, the position feedback system and the interference optical system; the control system is used to control the movement of the diffractive optical element to compensate for errors in the stage.

In an embodiment of the invention, the errors of the workpiece stage comprise a coordinate positioning error, a course angle error, a yaw angle error and a pitch angle error, and the control system is used for controlling the diffractive optical element to translate along the direction vertical to the optical axis so as to compensate the coordinate positioning error of the workpiece stage; controlling the diffraction optical device to rotate around the optical axis by using the control system so as to compensate the course angle error of the workpiece table; and controlling the diffractive optical device to move along the direction of the optical axis by using the control system so as to compensate the errors of the yaw angle and/or the pitch angle of the workpiece table.

In the embodiment of the invention, a reference grating is arranged on the workpiece table, the reference grating and the photoetching substrate are fixedly arranged, and a two-dimensional grating is arranged above the reference grating;

forming a recognizable moire pattern between the two-dimensional grating and the reference grating by using light source irradiation;

and identifying the Moire pattern by using an image acquisition module, and quantitatively analyzing the change of the Moire pattern to calculate the coordinate positioning error, the course angle error, the yaw angle error and the pitch angle error of the workpiece table.

In the embodiment of the invention, a first interference measurement module and a second interference measurement module are arranged on the peripheral side of the workpiece platform, and the control system is used for calculating the coordinate positioning error, the heading angle error, the yaw angle error and the pitch angle error of the workpiece platform according to the differential interference measurement light path.

The large-area nano photoetching system is characterized in that a photoetching substrate to be photoetched is arranged on a workpiece table; the position feedback system is used for measuring and calculating the error of the workpiece table; the interference optical system is used for generating an interference exposure field and carrying out interference photoetching on the photoetching substrate and comprises a diffraction optical device; the control system is electrically connected with the workpiece table, the position feedback system and the interference optical system respectively; a control system controls movement of the diffractive optical element to compensate for errors in the stage. The large-area nano-photoetching system can realize high-progress splicing among interference light fields and achieve the aim of high-precision preparation of large-area nano structures.

Drawings

FIG. 1 is a schematic structural diagram of a large-area nanolithography system according to a first embodiment of the present invention.

Fig. 2a and 2c are schematic diagrams of the workpiece stage of the present invention when the workpiece stage has errors in the moving process.

Fig. 3a to 3c are schematic diagrams of different adjustment states of the diffractive optical element according to the invention.

Fig. 4a to 4c are schematic diagrams of different errors occurring in the lithographic process of the present invention.

Fig. 5a to 5c are schematic diagrams of error detection by moire patterns.

Fig. 6 is a schematic structural diagram of a position feedback system according to a second embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be further described with reference to the accompanying drawings.

First embodiment

FIG. 1 is a schematic structural diagram of a large-area nanolithography system according to a first embodiment of the present invention. As shown in FIG. 1, large area nanolithography system 100 includes a workpiece stage 10, a position feedback system 20, an interference optical system 30, and a control system 40.

Fig. 2a and 2c are schematic diagrams of the workpiece stage of the present invention when the workpiece stage has errors in the moving process. As shown in fig. 2a to 2c, a photolithographic substrate 11 to be photoetched is disposed on the workpiece stage 10, and the workpiece stage 10 can move along two directions to satisfy the splicing function of the nanostructure. The width direction of the workpiece table 10 is defined as a first direction X, the length direction of the workpiece table 10 is defined as a second direction Y, and the height direction of the workpiece table 10 is defined as a third direction Z, wherein the first direction X is perpendicular to the second direction Y, and the third direction Z is perpendicular to the first direction X and the second direction Y. The present invention uses a two-axis workpiece stage 10, i.e., the workpiece stage 10 is movable along a first direction X and a second direction Y. When the workpiece table 10 moves, errors may occur in the workpiece table 10, where the errors include errors of coordinate positioning, a heading angle (Yaw), a Yaw angle (Roll), a Pitch angle (Pitch), orthogonality, and the like, where the coordinates of the workpiece table 10 (as shown in fig. 2 a) may cause a phase difference error of the pattern, the heading angle of the workpiece table 10 (as shown in fig. 2 b) may cause an angle error of pattern stitching, and errors of the Yaw angle and the Pitch angle of the workpiece table 10 (as shown in fig. 2 c) may cause a period error of the pattern, and these errors may affect the stitching accuracy of the pattern.

As shown in fig. 1, the position feedback system 20 includes a light source 21, an image acquisition module 22, a reference grating 23a, a two-dimensional grating 23b, a plurality of first lenses 24, and a first beam splitter 25. The reference grating 23a is arranged on the workpiece table 10, and the reference grating 23a is fixedly arranged with the lithography substrate 11, that is, the relative position of the reference grating 23a and the lithography substrate 11 is not changed during the movement of the workpiece table 10. The two-dimensional grating 23b is arranged above the reference grating 23a, and the distance between the two-dimensional grating 23b and the reference grating 23a is less than 1 mm. The light source 21 illuminates to form a recognizable moire pattern between the two-dimensional grating 23b and the reference grating 23a, the image acquisition module 22 recognizes the moire pattern, and the moire pattern is subjected to quantitative analysis to calculate a coordinate positioning error, a course angle error, a yaw angle error and a pitch angle error of the workpiece stage 10. The image acquisition module 22 is arranged above the two-dimensional grating 23b, the plurality of first lenses 24 are arranged between the image acquisition module 22 and the two-dimensional grating 23b, the first beam splitter 25 is arranged between the plurality of first lenses 24, the light source 21 is arranged on one side of the first beam splitter 25, and light emitted by the light source 21 is emitted to the two-dimensional grating 23b and the reference grating 23a through the first beam splitter 25.

In the present embodiment, in order to achieve the detection resolution of the nanometer scale, the reference grating 23a and the two-dimensional grating 23b do not need to be of the nanometer scale, and a grating having a period of 20 μm is preferable, and the detection resolution of 10nm or less can be achieved by interpolation subdivision of moire patterns.

The two-dimensional moire pattern formed between the reference grating 23a and the two-dimensional grating 23b has a corresponding relationship with the relative position change between the two gratings, for example, the relative translation between the reference grating 23a and the two-dimensional grating 23b can generate a corresponding translation for the moire pattern; the parallelism between the reference grating 23a and the two-dimensional grating 23b changes, and the period of moire fringes changes; the moire pattern is rotated by the change of the angle between the reference grating 23a and the two-dimensional grating 23 b. In practice, the variation of the moire pattern is a combination of the above cases, and the image acquisition module 22 needs to decompose and calculate the variation to determine the variation data of the coordinates, the heading angle, the yaw angle and the pitch angle. The moire principle is the basis of a data calculation method, and the specific values thereof are related to parameters such as a grating, an optical system, the image acquisition module 22, and the like, and the specific calculation method is not described in the present invention.

As shown in FIG. 1, the interference Optical system 30 includes a second laser 31, a beam shaper 32, a second lens 33, a third lens 34, a Diffractive Optical element 35 (DOE), a second beam splitter 36, a miniature objective 37, and a detection Optical path 38. The beam shaper 32 is disposed between the second laser 31 and the second lens 33, and the laser light emitted from the second laser 31 passes through the beam shaper 32 to form a flat-top beam. The second lens 33 and the third lens 34 form a 4F imaging system, the diffractive optical device 35 is disposed between the second lens 33 and the third lens 34, the detection optical path 38 is disposed on the transmission optical path of the second beam splitter 36, and the laser light emitted by the second laser 31 passes through the beam shaper 32, the second lens 33, the diffractive optical device 35, the third lens 34, the second beam splitter 36 and the miniature objective lens 37 in sequence, and forms an interference exposure field on the photolithographic substrate 11. The structured light field from the modulation end of the diffractive optical device 35 to the surface of the photolithographic substrate 11 is a miniature interference process, the miniature proportion is preferably 10-200 times, the translation adjustment proportion of the output surface is 1/(miniature multiple 2), the orientation angle adjustment proportion is 1, and the periodic adjustment proportion is determined by the parameters and the miniature proportion of a 4F system consisting of the second lens 33 and the third lens 34. The second laser 31 may be a gas laser, a solid-state laser, or an excimer laser, and for example, for a structure of 100nm or more, a Near Ultraviolet (NUV) helium-cadmium laser (325nm), a YAG solid-state laser (355nm), or an excimer laser (308nm) may be used; for microstructures below 100nm, a Deep Ultraviolet (DUV) light source 21 with a shorter wavelength is required, such as 266nm solid-state lasers, excimer lasers (248nm, 197nm, 157nm), and the like.

In this embodiment, the diffractive optical element 35 has a multi-degree-of-freedom movement function, specifically, the diffractive optical element 35 moves in a direction along the optical axis 101, rotates around the optical axis 101, and translates perpendicular to the optical axis 101, and the interference optical field forms a periodic change on the surface of the lithographic substrate 11, for example, the diffractive optical element 35 rotates around the optical axis 101, and the orientation angle of the interference optical field changes; the diffractive optical element 35 is translated perpendicular to the optical axis 101, and the structural distribution in the interference optical field is correspondingly translated.

FIGS. 3a to 3c are schematic diagrams of different adjustment states of the diffractive optical device of the present invention, FIGS. 4a to 4c are schematic diagrams of different errors occurring in the photolithography process of the present invention, FIGS. 5a to 5c are schematic diagrams of errors detected by moire patterns, referring to FIGS. 3a to 5c, a control system 40 is electrically connected to the stage 10, the position feedback system 20 and the interference optical system 30, specifically, a control system 40 is electrically connected to the stage 10, the light source 21, the image acquisition module 22, the diffractive optical device 35 and the detection optical path 38, respectively, the control system 40 controls the movement of the diffractive optical device 35 to compensate for errors of the stage 10, for example, FIG. ① in FIG. 4a is a previous image having been completed by photolithography, FIG. ② is a next image having coordinate positioning errors, FIG. 5a shows coordinate positioning errors detected by moire patterns, FIG. 3a shows control system 40 controls the diffractive optical device 35 to translate along the direction of the optical axis 101 to compensate for the existence of coordinate positioning errors of the stage 10, FIG. 3b is a control system to compensate for the existence of a lateral positioning errors of the image of the stage 10, the lateral angle of the diffraction optical device 35, and/or a lateral angle of the control system 40 to compensate for the existence of the lateral angle of the image shown in the lateral angle of the image shown in the lateral angle of the lateral angle shown in the control system shown in the control of the control system 40, the control of the control system 40, the control of.

The large-area nano-lithography system 100 of the invention calculates the position information of the workpiece stage 10 through the position feedback system 20, and forms closed-loop control by adjusting the diffractive optical element 35 of the interference optical system 30, so that the error between the current position and the theoretical position of the lithography substrate 11 can be accurately analyzed in the operation process of the workpiece stage 10, and the required coordinate measurement precision range can be satisfied and is 0.1 nm-300 nm, preferably 1 nm-100 nm; the measurement precision of the course angle, the yaw angle and the pitch angle is 0.1-10 arcsec; the resolution and precision of the change can meet the requirement of compensating the error. The photoetching substrate 11 is exposed, the step motion between the interference optical system 30 and the photoetching substrate 11 is repeated in the operation process of the workpiece table 10, and the steps of detecting the coordinate, the course angle, the yaw angle and the pitch angle of the workpiece table 10, adjusting, compensating and exposing the diffraction optical device 35 are repeated, so that the high-progress splicing between interference light fields is realized, the purpose of preparing a large-area nano structure at high precision is achieved, and the problem of light field splicing of digital holographic interference photoetching can be effectively solved.

Second embodiment

Fig. 6 is a schematic structural diagram of a position feedback system according to a second embodiment of the present invention. As shown in fig. 6, the large-area nanolithography system 100 of the present embodiment has substantially the same structure as the large-area nanolithography system 100 of the first embodiment, but differs in the structure of the position feedback system 20.

Specifically, as shown in fig. 4, the position feedback system 20 includes a first laser 26, a first interferometry module 27, a second interferometry module 28, and a plurality of semi-transparent semi-reflective mirrors 29. The first laser 26 provides laser sources for the first interference measurement module 27 and the second interference measurement module 28 through a plurality of semi-transparent and semi-reflective mirrors 29, the first interference measurement module 27 and the second interference measurement module 28 are arranged on the periphery of the workpiece table 10, the control system 40 is electrically connected with the first laser 26, the first interference measurement module 27 and the second interference measurement module 28 respectively, and the control system 40 calculates the coordinate positioning error, the course angle error, the yaw angle error and the pitch angle error of the workpiece table 10 according to the differential interference measurement light path. The first interferometric measuring module 27 emits a measurement beam path along a first direction X and the second interferometric measuring module 28 emits a measurement beam path along a second direction Y.

Third embodiment

The present invention also relates to a large area nanolithography method using the large area nanolithography system 100 described above, the method comprising:

step one, providing a workpiece table 10, and arranging a photoetching substrate 11 to be photoetched on the workpiece table 10.

And step two, providing a position feedback system 20, and calculating the error of the workpiece table 10 by using the position feedback system 20.

In the present embodiment, the position feedback system 20 includes a light source 21, an image acquisition module 22, a reference grating 23a, a two-dimensional grating 23b, a plurality of first lenses 24, and a first beam splitter. The reference grating 23a is arranged on the workpiece table 10, and the reference grating 23a is fixedly arranged with the lithography substrate 11, that is, the relative position of the reference grating 23a and the lithography substrate 11 is not changed during the movement of the workpiece table 10. The two-dimensional grating 23b is arranged above the reference grating 23a, and the distance between the two-dimensional grating 23b and the reference grating 23a is less than 1 mm. The light source 21 illuminates to form a recognizable moire pattern between the two-dimensional grating 23b and the reference grating 23a, the image acquisition module 22 recognizes the moire pattern, and the moire pattern is subjected to quantitative analysis to calculate errors of the workpiece stage 10, wherein the errors include coordinate positioning errors, course angle errors, yaw angle errors and pitch angle errors. The image acquisition module 22 is arranged above the two-dimensional grating 23b, the plurality of first lenses 24 are arranged between the image acquisition module 22 and the two-dimensional grating 23b, the first beam splitter 25 is arranged between the plurality of first lenses 24, the light source 21 is arranged on one side of the first beam splitter 25, and light emitted by the light source 21 is emitted to the two-dimensional grating 23b and the reference grating 23a through the first beam splitter 25.

In another preferred embodiment, the position feedback system 20 includes a first laser 26, a first interferometric module 27, a second interferometric module 28, and a plurality of semi-transparent and semi-reflective mirrors 29. The first laser 26 provides laser sources for the first interference measurement module 27 and the second interference measurement module 28 through a plurality of semi-transparent and semi-reflective mirrors 29, the first interference measurement module 27 and the second interference measurement module 28 are arranged on the periphery of the workpiece table 10, the control system 40 is electrically connected with the first laser 26, the first interference measurement module 27 and the second interference measurement module 28 respectively, and the control system 40 calculates the coordinates, the course angle, the yaw angle and the pitch angle of the workpiece table 10 according to the differential interference measurement light path. The first interferometric measuring module 27 emits a measurement beam path along a first direction X and the second interferometric measuring module 28 emits a measurement beam path along a second direction Y.

And step three, providing an interference Optical system 30, and performing interference lithography on the lithography substrate 11 by using the interference Optical system 30, wherein the interference Optical system 30 comprises a diffraction Optical element 35 (DOE).

In the present embodiment, the interference optical system 30 further includes a second laser 31, a beam shaper 32, a second lens 33, a third lens 34, a second beam splitter 36, a miniature objective 37, and a detection optical path 38. The beam shaper 32 is disposed between the second laser 31 and the second lens 33, and the laser light emitted from the second laser 31 passes through the beam shaper 32 to form a flat-top beam. The second lens 33 and the third lens 34 form a 4F imaging system, the diffractive optical device 35 is disposed between the second lens 33 and the third lens 34, the detection optical path 38 is disposed on the transmission optical path of the second beam splitter 36, and the laser light emitted by the second laser 31 passes through the beam shaper 32, the second lens 33, the diffractive optical device 35, the third lens 34, the second beam splitter 36 and the miniature objective lens 37 in sequence, and forms an interference exposure field on the photolithographic substrate 11.

Step four, providing a control system 40, wherein the control system 40 is electrically connected with the workpiece table 10, the position feedback system 20 and the interference optical system 30 respectively; the control system 40 is used to control the movement of the diffractive optical element 35 to compensate for errors in the workpiece stage 10.

Specifically, the control system 40 is used to control the diffractive optical element 35 to translate along the direction perpendicular to the optical axis 101, so as to compensate the coordinate positioning error of the workpiece stage 10; controlling the diffractive optical element 35 to rotate around the optical axis 101 by using the control system 40 so as to compensate the course angle error of the workpiece table 10; the control system 40 is used to control the movement of the diffractive optical element 35 along the optical axis 101 to compensate for errors in the yaw and/or pitch of the stage 10.

The large-area nano photoetching system 100 is provided with a photoetching substrate 11 to be photoetched on a workpiece table 10; the position feedback system 20 is used for measuring and calculating the error of the workpiece table 10; the interference optical system 30 is used for generating an interference exposure field and performing interference lithography on the lithography substrate 11, and the interference optical system 30 comprises a diffraction optical device 35; the control system 40 is electrically connected with the workpiece table 10, the position feedback system 20 and the interference optical system 30 respectively; the control system 40 controls the movement of the diffractive optical element 35 to compensate for errors in the workpiece stage 10. The large-area nano lithography system 100 of the present invention can realize high-progress splicing between interference light fields, and achieve the purpose of high-precision preparation of large-area nano structures.

The present invention is not limited to the specific details of the above-described embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention. The various features described in the foregoing detailed description may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.