CN117666292A - Light path structure for polarized interference lithography and polarized interference lithography system - Google Patents

Abstract

The invention provides a light path structure for polarized interference lithography and a polarized interference lithography system, wherein the light path structure comprises a light source module, a polarization component, a light splitting component and an imaging component which are connected in series on a light path; the light source module is used for generating a linearly polarized light beam with coherent characteristics; the light splitting assembly is used for splitting the injected light into two beams of light and emitting the two beams of light to the imaging assembly, the included angle of the two beams of light is variable and the two beams of light can rotate around the optical axis of the incident light, and the imaging assembly is used for converging the two beams of light on the surface of the photoetching substrate; the light splitting component is matched with the polarizing component and used for carrying out optical modulation on linearly polarized light, so that when a light beam reaches a photoetching substrate, the light beam is two circularly polarized lights with opposite polarization directions, and a polarized interference light field is formed. The invention establishes a polarized interference lithography system, can adjust parameters such as period, orientation and the like of a polarized structure in a light field by controlling a light splitting component and a polarized component, performs photochemical reaction with a polarized photosensitive material to form specific polarized pattern distribution, and controls the coordinate positioning of the polarized light field parameter and a substrate according to a predefined polarized pattern design file to perform light field splicing lithography to form expected polarized pattern distribution on a photoetching substrate.

Description

Light path structure for polarized interference lithography and polarized interference lithography system

Technical Field

The invention relates to the technical field of advanced manufacturing, in particular to a light path structure for polarized interference lithography and a polarized interference lithography system.

Background

Liquid crystal is an important material in the current display field, and in recent years, application of the liquid crystal material to photonic devices is becoming a research hot spot, such as liquid crystal polarization gratings, liquid crystal vortex phase plates, optical communication and other photonic devices. The liquid crystal alignment technology is widely adopted, but is single, and is widely used in liquid crystal display manufacturing in early stage, but can not meet the flexible, various and controllable demands of alignment required by the development of the liquid crystal device. The photo-alignment technology is a non-contact alignment method for realizing alignment by polarized light irradiation, and alignment zoning control can be realized by region-by-region polarized exposure control on specific photo-alignment materials, which provides a principle method for the development of liquid crystal devices.

The preparation process of the liquid crystal photon device mainly comprises the following steps: 1) Cleaning a substrate; 2) Coating photo-oriented materials; 3) Patterning the photo-oriented material; 4) Coating active liquid crystal; 5) Curing the active liquid crystal; 6) And (5) packaging the device. The patterning of the photo-alignment material is a key link for preparing devices, in general, the photo-alignment can obtain polarized light by adopting a method that light rays of a light source are transmitted through a polaroid, the polarization orientation of the light can be changed by rotating the polaroid by taking the direction of the light rays as an axis, and the light with different polarization orientations is exposed on different areas of the photo-alignment material, so that the zoned alignment preparation is realized.

If a flexible and high-precision zoned photo-alignment pattern preparation technology can be developed, an effective technical means can be provided for the development of liquid crystal photon devices. Related preparation technical researches are carried out in scientific research institutes at present, a polarization direct-writing photoetching scheme projected by a spatial light modulator is mainly adopted, polarized light with changed orientation is obtained by rotating a polaroid, and an exposure area is controlled by combining the spatial light modulator and an objective table in a linkage way, so that photoetching with zoned and polarized orientation changed is carried out on the surface of a light orientation material, and orientation patterning is formed. However, in the technical scheme, the resolution of the polarized light field depends on the resolution of a projection optical system, the polarization orientation is changed by mechanically rotating a polaroid, and the technical scheme has the problem of limitation when the challenges of resolution, precision, large-breadth photoetching efficiency and the like of complex orientation are faced. The prior art cannot obtain a polarized light field with continuously changing polarization orientation, and cannot realize flexible and high-precision zoned light orientation graphic control.

The foregoing description is provided for general background information and does not necessarily constitute prior art.

Disclosure of Invention

The invention aims to provide a light path structure for polarized interference lithography, which can obtain a polarized light spot with controllable parameters, wherein the polarization direction in the light spot is periodically and continuously changed and distributed, and the periodic and distributed directions have a mapping relation with parameters such as the states of devices in the light path.

The invention provides a light path structure for polarized interference lithography, which comprises a light source module, a polarization component, a light splitting component and an imaging component which are connected in series on a light path; the light source module is used for generating a linearly polarized light beam with coherent characteristics; the light splitting assembly is used for splitting the injected light into two beams of light and emitting the two beams of light to the imaging assembly, the included angle of the two beams of light is variable and the two beams of light can rotate around the optical axis of the incident light, and the imaging assembly is used for converging the two beams of light on the surface of the photoetching substrate; the light splitting component is matched with the polarizing component and used for carrying out optical modulation on linearly polarized light, so that when a light beam reaches a photoetching substrate, the light beam is two circularly polarized lights with opposite polarization directions, and a polarized interference light field is formed.

Further, the polarized interference light field can form a light spot with a linear polarization pattern with periodically changed direction on the surface of the photoetching substrate, the period of the linear polarization pattern is changed by changing the included angle of two beams of light reaching the surface of the photoetching substrate by utilizing the polarization component, the light splitting component and the imaging component, and the orientation of the linear polarization pattern is changed by changing the included angle of the plane where the two beams of light are located and the X-axis on the XY coordinate system of the surface of the photoetching substrate.

Further, the beam splitting component comprises a beam splitting element and a 4f optical element, wherein the beam splitting element can rotate around the optical axis and axially move, so that the continuous change of an included angle of an emergent beam and the rotation around the optical axis are realized.

Further, the imaging assembly comprises a first optical lens group and a second optical lens group, and an infinite optical path is arranged between the first lens group and the second lens group.

Further, the polarization component comprises a 1/4 wave plate, an optical path compensation window and a 1/2 wave plate; the 1/4 wave plate is arranged in front of the light splitting component and is used for converting linearly polarized light into circularly polarized light; the optical path compensation window and the 1/2 wave plate are arranged between the first lens group and the second lens group in parallel, the positions of the optical path compensation window and the 1/2 wave plate correspond to the two incident light beams respectively, and the optical path compensation window is used for matching the optical path difference of the two light beams; the 1/2 wave plate is used for reversing the polarization direction of the incident circularly polarized light; the optical path compensation window and the 1/2 wave plate can rotate around the center of the optical path and synchronously rotate with the light splitting assembly so as to keep the positions of the optical path compensation window and the 1/2 wave plate corresponding to the two incident light beams respectively, so that after passing through the 1/4 wave plate and the light splitting assembly, circularly polarized light which is split into two beams passes through the 1/2 wave plate and the optical path compensation window respectively to become circularly polarized light with opposite polarization directions.

Further, the polarization component comprises two 1/4 wave plates, the two 1/4 wave plates are arranged between the first lens group and the second lens group in parallel, and the positions of the two wave plates respectively correspond to the two incident light beams; when the light splitting assembly rotates, the two 1/4 wave plates can synchronously rotate around the center of the light path, the two 1/4 wave plates are orthogonal and respectively translate on the circumference, so that the included angle between the optical axes of the two 1/4 wave plates and the polarization direction of incident ray polarized light is kept unchanged, the light is split into two linearly polarized light beams after passing through the light splitting assembly, and the two linearly polarized light beams are converted into two circularly polarized light beams with opposite polarization directions after passing through the two 1/4 wave plates.

Further, the polarization component comprises a 1/4 wave plate, an optical path compensation window and a 1/2 wave plate, wherein the 1/4 wave plate, the optical path compensation window and the 1/2 wave plate are arranged between the first lens group and the second lens group; the optical path compensation window and the 1/2 wave plate are arranged between the first lens group and the second lens group in parallel, the optical path compensation window is used for matching the optical path difference of two light beams, and the 1/2 wave plate is used for reversing the polarization direction of the incident circularly polarized light; the 1/4 wave plate is arranged in front of the optical path compensation window and the 1/2 wave plate and is used for converting linearly polarized light into two circularly polarized light beams with the same polarization direction; the optical path compensation window and the 1/2 wave plate are respectively corresponding to the two incident light beams, and when the light splitting assembly rotates, the optical path compensation window and the 1/2 wave plate can synchronously rotate around the center of the optical path so as to keep the positions of the optical path compensation window and the 1/2 wave plate to respectively correspond to the two incident light beams, so that after the optical splitting assembly and the 1/4 wave plate pass through the light splitting assembly, two circularly polarized lights with the same polarization direction respectively pass through the 1/2 wave plate and the optical path compensation window to form two circularly polarized lights with opposite polarization directions.

Further, the polarization component comprises a 1/4 wave plate, an optical path compensation window and a 1/2 wave plate, wherein the 1/4 wave plate, the optical path compensation window and the 1/2 wave plate are arranged between the first lens group and the second lens group; the optical path compensation window and the 1/2 wave plate are arranged between the first lens group and the second lens group in parallel, the optical path compensation window is used for matching the optical path difference of two light beams, the 1/2 wave plate is used for rotating the polarization direction of the incident linearly polarized light by 90 degrees, and the positions of the optical path compensation window and the 1/2 wave plate respectively correspond to the two incident light beams; the 1/4 wave plate is arranged behind the optical path compensation window and the 1/2 wave plate and is used for converting linearly polarized light into circularly polarized light; when the light splitting assembly rotates, the optical path compensation window and the 1/2 wave plate can synchronously rotate around the center of the optical path, and meanwhile, the 1/2 wave plate moves horizontally on the circumference, so that an included angle between the linear polarization direction of the incident light and the optical axis direction of the 1/2 wave plate is kept unchanged, and two beams of light pass through the 1/4 wave plate to form two beams of circularly polarized light with opposite polarization directions.

Further, the polarization component comprises a 1/2 wave plate and two 1/4 wave plates; the 1/2 wave plate is arranged in front of the light splitting component; the two 1/4 wave plates are arranged between the first lens group and the second lens group in parallel, the positions of the two 1/4 wave plates respectively correspond to the two incident light beams, the two 1/4 wave plates are orthogonal, and the incident linear polarized light is converted into two circularly polarized light beams with opposite polarization directions after passing through the two 1/4 wave plates; the 1/2 wave plate can rotate, the two 1/4 wave plates can rotate around the center of the optical path, the rotation of the 1/2 wave plate and the two 1/4 wave plates is matched with the rotation of the light splitting assembly, the light splitting assembly rotates synchronously, the linearly polarized light beam incident on the 1/4 wave plate always keeps a fixed included angle with the optical axis of the 1/4 wave plate, the linearly polarized light beam is split into two beams of linearly polarized light after passing through the light splitting assembly, and the two beams of linearly polarized light beam are converted into two beams of circularly polarized light with opposite polarization directions after passing through the two 1/4 wave plates.

The invention also provides a polarization interference lithography system, which comprises the optical path structure, an optical path regulating and controlling component, a motion platform, an electric control system and control software, wherein the optical path regulating and controlling component is connected with the optical path structure and used for regulating and controlling the motions of the polarization component, the light splitting component and the imaging component; the motion platform carries the photoetching substrate and enables the photoetching substrate to move on an XY axis so as to realize transverse pattern splicing; the electric control system is connected with the light path regulating and controlling component and the motion platform, and the light path regulating and controlling component and the motion platform are controlled by combining the control software.

According to the light path structure for polarization lithography and the polarization interference lithography system, the light source module, the polarization component, the light splitting component and the imaging component which are connected in series on the light path are subjected to optical modulation, so that when a light beam reaches a lithography substrate, the light beam is two circularly polarized lights with opposite polarization directions, and a polarization interference light field is formed. According to the polarized interference lithography system provided by the invention, parameters such as the period, the orientation and the like of a polarized structure in a light field can be regulated by controlling the light splitting component and the polarized component, photochemical action is carried out on the polarized structure and the polarized photosensitive material, specific polarized pattern distribution is formed, the polarized lithography system controls the coordinate displacement of the polarized light field parameters and the substrate according to a predefined polarized pattern design file, light field splicing lithography is carried out, and expected polarized pattern distribution is formed on the photoetching substrate.

Drawings

FIG. 1 is a schematic diagram of a first embodiment of an optical path structure for polarized interference lithography according to the present invention.

FIG. 2 is a schematic diagram of a redirecting structure in the optical path structure for polarized interference lithography shown in FIG. 1.

FIG. 3 is a schematic diagram of two parameters of an outgoing beam regulated by a beam splitting component.

FIG. 4 is a schematic diagram of two alternative configurations of a 1/2 wave plate and an optical path compensation window in a polarizing assembly in the optical path configuration for polarized interference lithography shown in FIG. 1.

Fig. 5 is a schematic diagram of generating two circularly polarized light beams with opposite polarization directions by a polarization component in the optical path structure for polarized interference lithography shown in fig. 1.

FIG. 6 is a schematic diagram of a polarized light spot with controllable parameters obtained from the optical path structure of polarized interference lithography.

Fig. 7 is an enlarged view of a portion of the polarized spot of fig. 6.

Fig. 8a and 8b are schematic diagrams of the distribution of the polarization pattern structures regulated by different parameters.

FIG. 9 is a schematic diagram showing the correspondence between the beam splitting component, the 1/2 wave plate special device, and the polarization structure pattern state in the optical path structure for polarization interference lithography shown in FIG. 1.

FIG. 10 is a schematic diagram of a second embodiment of an optical path structure for polarized interference lithography according to the present invention.

Fig. 11 is a schematic diagram showing rotation of two linearly polarized light beams along the optical axis in the second embodiment.

FIG. 12 is a schematic diagram of a third embodiment of an optical path structure for polarized interference lithography according to the present invention.

FIG. 13 is a schematic diagram of a fourth embodiment of an optical path structure for polarized interference lithography according to the present invention.

FIG. 14 is a schematic diagram of a fifth embodiment of an optical path structure for polarized interference lithography according to the present invention.

Fig. 15 is a schematic view showing rotation of two linearly polarized light beams along the optical axis in the fifth embodiment.

FIG. 16 is a schematic diagram of a polarized interference lithography system according to an embodiment of the invention.

FIG. 17 is a schematic diagram of a distribution structure of a digital interference lithography polarization pattern produced by the polarization interference lithography system of FIG. 16.

Detailed Description

The following describes in further detail the embodiments of the present invention with reference to the drawings and examples. The following examples are illustrative of the invention and are not intended to limit the scope of the invention.

Fig. 1 and 2 show a first embodiment of the optical path structure for polarized interference lithography according to the present invention. In this embodiment, the optical path structure for polarization interference lithography includes a light source module, a beam splitting component, and an imaging component connected in series on an optical path.

The light source module is used for generating a linearly polarized light beam with coherent characteristics and comprises a luminous light source and necessary optical components such as beam expanding, collimation, shaping and the like. The preferred light source is a laser with coherent characteristics, such as a solid state laser, a semiconductor laser, a helium-cadmium gas laser, an inert gas ion laser, an excimer laser, etc., which can emit a linear polarized light beam with coherence, the aperture of the light beam is generally 1-3 mm, and necessary beam expansion collimation devices are added to form the light source module of the invention. The emergent light beam of the light source module has a certain caliber and meets the requirements of a subsequent optical system. The type and wavelength of the laser is selected according to the photosensitive characteristics of the material to be processed on the substrate, for example, a 355nm ultraviolet pulse solid state laser, a 405nm semiconductor laser, a 441.6nm helium cadmium laser, etc. can be selected for a liquid crystal photosensitive alignment material sensitive to bluish violet light.

As shown in fig. 3, the beam splitting component is configured to split an incident beam into two beams and direct the two beams to the imaging component, where the incident beam is split into two beams after passing through the beam splitting component. Two parameters of the emergent light beam are regulated and controlled by the light splitting component, the included angle of the two light beams is variable, and the emergent direction of the two light beams can rotate around the optical axis of the incident light beam. The beam splitting component is used as a necessary functional implementation component of the polarized interference light path of the present invention, the type of the beam splitting component is not particularly limited, the polarization state of the outgoing beam is the same as that of the incoming beam, the beam splitting component does not change the polarization state of the beam, for example, the incoming beam is right circularly polarized light, and both outgoing beams are right circularly polarized light. The beam splitting assembly may comprise a beam splitting element 2 and/or a 4f optical element capable of rotating around the optical axis and moving axially, and in this embodiment, the beam splitting element 2 and the 4f optical element are preferably included at the same time, so as to realize continuous change of the included angle of the outgoing beam and rotation around the optical axis.

The imaging component is used for converging two beams of light on the surface of the photoetching substrate 1, and the two beams of light form interference on a processing material. In order to realize the polarization control function of the present invention, the imaging assembly of the present invention is composed of a first optical lens group 41 and a second optical lens group 42, between which an infinity optical path is provided for arranging polarizing optical elements. In particular, the first lens group may be a tube lens (tube) and the second lens group may be a lithography objective lens.

The polarization component is used for being matched with the light splitting component to convert one beam of linearly polarized light into two beams of circularly polarized light with opposite polarization directions. In this embodiment, the polarization assembly includes a 1/4 wave plate 611, an optical path compensation window 612, and a 1/2 wave plate 613. The 1/4 wave plate 611 is disposed before the beam splitting assembly 2 to convert the linearly polarized light into circularly polarized light. The optical path compensation window 612 and the 1/2 wave plate 613 are fixed on the transparent disk 614, and the three form a redirecting structure (this embodiment may also be referred to as a "1/2 wave plate dedicated device"). In other embodiments, the optical path compensation window 612 and the 1/2 wave plate 613 may have other shapes, or may be fixed by other manners, for example, they are all semicircular and directly fixed to form a circle). The optical path compensation window 612 and the 1/2 wave plate 613 are disposed in parallel between the first lens group 41 and the second lens group 42, and their positions respectively correspond to the two incident light beams. The optical path compensation window 612 and the 1/2 wave plate 613 rotate synchronously with the beam splitting component 2 around the center of the optical path by the rotation of the transparent disk 614, so as to keep the positions of the optical path compensation window and the 1/2 wave plate corresponding to the two incident light beams respectively. The 1/2 wave plate 613 is used for reversing the incident circularly polarized light, and the optical path compensation window 612 is used for matching the optical path difference of the two light beams, so that the coherence of the two light beams on the substrate is ensured. If a gas laser is used as the light source, the coherence length of the gas laser is longer, and air can replace the optical path compensation window, and for a solid laser or a semiconductor laser, the coherence length is short, and the window is preferably arranged, and the material and the thickness of the window are based on the optical path matched with the 1/2 wave plate, so that those skilled in the art can understand that the specific explanation is omitted here.

Based on the above principle, in the embodiments of the present application, the 1/2 wave plate and the optical path compensation window in the polarization component may be configured in a plurality of different structures, for example, as shown in fig. 4, where the structure (a) is a usable polarization component structure, and the 1/2 wave plate and the optical path compensation window are configured in a semicircle; wherein structure (b) is another useful polarization component structure arrangement, with both the 1/2 wave plate and the optical path compensation window being arranged in a circular shape.

In this way, the polarization component of the embodiment converts the linear polarized light into the circular polarized light by using the 1/4 wave plate 611, and after the circular polarized light is split into two beams of circular polarized light by the light splitting component 2, in the direction-changing structure, one beam passes through the optical path compensation window 612 with the polarization direction unchanged, and the other beam passes through the 1/2 wave plate 613 to reverse the polarization direction of the circular polarized light, so that two beams of circular polarized light with opposite polarization directions are formed, further a polarized interference light field is formed, and a pattern light spot with a polarization structure is formed on the substrate. The basic working principle of which can be seen in fig. 5.

The polarized interference light field can form light spots with linear polarization patterns with periodically changed directions on the surface of the photoetching substrate, the period of the linear polarization patterns is changed by changing the included angles of two beams of light reaching the surface of the photoetching substrate by utilizing the polarization component, the light splitting component and the imaging component, and the orientation of the linear polarization patterns is changed by changing the included angles of the plane where the two beams of light are located and the X axis on the XY coordinate system of the surface of the photoetching substrate. The following is a brief description.

According to the definition in physics, the interference phenomenon of light is that two or more light waves meeting the coherence condition are used, the light intensity of certain points is always strengthened in the superposition area, the light intensity of certain points is always weakened, namely quite stable light and dark alternate stripe distribution is formed in space, and sometimes, the light intensity received at a certain fixed point changes alternately according to a certain rule when a certain parameter of the interference device changes with time. When two circularly polarized lights with opposite rotation directions are overlapped together, interference fringes with traditional light and dark intervals cannot be generated, but if the phase difference between the circularly polarized lights is fixed, linearly polarized light spots with specific space distribution of the polarization directions can be formed by superposition, and the space distribution of the polarization directions can be different according to different light beam wavelength and included angle parameters, so that the optical phenomenon different from traditional coherence is called polarization interference.

As shown in fig. 6, 7, 8a and 8b, two circularly polarized lights with opposite rotation directions are incident on the substrate at a certain included angle, so that linearly polarized light spots with specific spatial distribution can be formed on the surface of the substrate. In xyz space, left-handed circularly polarized light beam I ₁ And right-handed circularly polarized light beam I ₂ The two circularly polarized light beams are incident on a plane a of an xy coordinate system at an included angle 2 theta, the plane b is vertical to the plane a, the included angle between the plane b and an x axis is phi, the polarized interference forms a light spot with a linear polarization pattern with periodically changed direction shown in the figure, the direction of the linear polarization pattern in the light spot is continuously changed, and the change rule is an sine type according to the principle of interference.

The periodic interval is d, d is related to the wavelength (lambda) of the light source and the included angle (2 theta) of the two beams of light, and d=lambda/(4×sin (theta)); the periodic orientation m is related to the direction of the plane b where the two beams of light are located, and the included angle between the orientation m and the x-axis is 90 degrees plus phi.

Therefore, under the condition of selecting the wavelength of the light source, the linear polarization pattern structure distribution in the plane a can be regulated and controlled by changing two parameters of theta and phi. The distribution schematic diagrams of the polarization pattern structures regulated by different parameters are shown in fig. 8a and 8 b. As shown in fig. 8a, the period d of the polarization pattern is changed by changing the included angle θ of the two beams; as shown in fig. 8b, changing the angle phi changes the orientation of the polarization pattern. Further, fig. 9 is a schematic diagram showing correspondence of a spectroscopic assembly, a 1/2 wave plate dedicated device, and a polarization structure pattern state in the optical path structure for polarization interference lithography of the present embodiment.

In this embodiment, when two beams of light rotate around the optical axis, the 1/2 wave plate special device needs to synchronously rotate around the optical axis along with the light beam, and because no optical axis alignment problem exists when circularly polarized light is modulated by the 1/2 wave plate, the rotation synchronism of the device only needs to meet that the light beam enters the corresponding optical window, so that only one rotation parameter around the optical axis is needed for the mechanism motion freedom degree of the 1/2 wave plate special device, and the strictly synchronous motion precision is not needed. Therefore, the design scheme of the invention reduces the technical difficulty of realizing the polarization regulation function.

Fig. 10 and 11 show a second embodiment of the optical path structure for polarized interference lithography according to the present invention. In this embodiment, the optical path structure for polarization interference lithography includes a light source module, a beam splitting component, and an imaging component connected in series on an optical path. The same contents as those of the first embodiment are not repeated, and the portions different from those of the first embodiment are described with emphasis.

In this embodiment, the polarization component includes two 1/4 wave plates 621, and two 1/4 wave plates 641 are movably disposed on the transparent disk 622, and the three form a redirecting structure (this embodiment may also be referred to as a "1/4 wave plate dedicated device"). Through the transparent disk 622, two 1/4 wave plates 621 are juxtaposed between the first lens group 41 and the second lens group 42 at positions corresponding to the two incident light rays, respectively. The two 1/4 wave plates 641 can rotate synchronously with the beam splitting assembly 2 around the center of the optical path by rotating the transparent disc 622 so as to keep the positions of the two wave plates corresponding to the two incident light beams respectively. The two 1/4 wave plates 621 are orthogonal, and the optical axis and the incident linear polarized light are respectively 45 degrees and-45 degrees, so that the incident linear polarized light is converted into two circularly polarized light with opposite polarization directions after passing through the two 1/4 wave plates 621. And the two 1/4 wave plates 621 translate on the transparent disc 622 respectively, so that the included angle between the optical axes of the two 1/4 wave plates 621 and the polarization direction of the incident linear polarized light is kept unchanged, and the incident linear polarized light is converted into two circularly polarized light beams with opposite polarization directions after passing through the two 1/4 wave plates 621. In this way, the polarization component of this embodiment directly uses two mutually orthogonal 1/4 wave plates 621 to convert two linearly polarized light beams into two circularly polarized light beams with opposite polarization directions, so as to form a polarized interference light field, and form a patterned light spot with a polarized structure on the substrate.

Fig. 11 shows that the linearly polarized light beam in this embodiment is split into two linearly polarized light beams after passing through the beam splitting assembly, and when the two linearly polarized light beams rotate around the optical axis, the 1/4 wave plate special device synchronously rotates around the optical axis, and meanwhile, the two 1/4 wave plates 621 translate on the transparent disc 622, which includes a perspective view and a top view.

FIG. 12 shows a third embodiment of the optical path structure for polarized interference lithography according to the present invention. In this embodiment, the optical path structure for polarization interference lithography includes a light source module, a beam splitting component, and an imaging component connected in series on an optical path. The same contents as those of the first embodiment are not repeated, and the portions different from those of the first embodiment are described with emphasis.

In this embodiment, the polarizing assembly includes a 1/4 wave plate 631, an optical path compensation window 632, and a 1/2 wave plate 633. The 1/4 wave plate 631, the optical path compensation window 632, and the 1/2 wave plate 633 are each disposed between the first lens group 41 and the second lens group 42. The optical path compensation window 632 and the 1/2 wave plate 633 are arranged between the first lens group and the second lens group in parallel, and in this embodiment, the optical path compensation window 632 and the 1/2 wave plate 633 are fixed on the transparent disk 634, and the three form a direction-changing structure (this embodiment may also be referred to as a "1/2 wave plate dedicated device"). The 1/4 wave plate 631 is disposed before the optical path compensation window 632 and the 1/2 wave plate 633 to convert the linearly polarized light into circularly polarized light. The optical path compensation window 632 and the 1/2 wave plate 633 are respectively corresponding to the two incident light beams, and the optical path compensation window 632 and the 1/2 wave plate 633 can synchronously rotate around the center of the optical path and the beam splitting assembly 2 by rotating the transparent disc 634 so as to keep the positions of the optical path compensation window 632 and the 1/2 wave plate 633 respectively corresponding to the two incident light beams. The 1/2 wave plate 633 is used to reverse the incoming circularly polarized light. In this way, the polarizing component of the embodiment converts two linearly polarized light beams formed after the light is split by the light splitting component 2 into circularly polarized light beams by using the 1/4 wave plate 631, one of the circularly polarized light beams is not turned through the optical path compensation window 632, and the other circularly polarized light beam is inverted in the polarization direction by passing through the 1/2 wave plate 633, so that two circularly polarized light beams with opposite polarization directions are formed, further a polarized interference light field is formed, and a patterned light spot with a polarized structure is formed on the substrate. FIG. 13 shows a fourth embodiment of the optical path structure for polarized interference lithography according to the present invention. In this embodiment, the optical path structure for polarization interference lithography includes a light source module, a beam splitting component, and an imaging component connected in series on an optical path. The same contents as those of the first embodiment are not repeated, and the portions different from those of the first embodiment are described with emphasis.

Referring to fig. 13, in the present embodiment, the polarizing component includes a 1/4 wave plate 641, an optical path compensation window 642, and a 1/2 wave plate 643. The 1/4 wave plate 641, the optical path compensation window 642, and the 1/2 wave plate 643 are each disposed between the first lens group 41 and the second lens group 42. The optical path compensation window 642 and the 1/2 wave plate 643 are arranged between the first lens group and the second lens group in parallel, and in this embodiment, the optical path compensation window 642 and the 1/2 wave plate 643 are fixed on the transparent disk 644, and the three form a direction-changing structure (this embodiment may also be referred to as a "1/2 wave plate dedicated device"). The optical path compensation window 642 and the 1/2 wave plate 643 are respectively corresponding to the two incident light beams, and the optical path compensation window 642 and the 1/2 wave plate 643 can synchronously rotate around the center of the optical path and the beam splitting component 2 by rotating the transparent disk 644 so as to keep the positions of the optical path compensation window 642 and the 1/2 wave plate 643 respectively corresponding to the two incident light beams. The 1/2 wave plate 643 is used for selecting the polarization direction of the incident linear polarized light to 90 degrees, so when the light splitting component 2 rotates, the 1/2 wave plate 643 translates on the circumference (transparent disk 644) so that the linear polarization direction of the incident light always forms an included angle of 45 degrees with the optical axis direction of the 1/2 wave plate 643. The 1/4 wave plate 641 is disposed behind the optical path compensation window 642 and the 1/2 wave plate 643 for converting the linearly polarized light into circularly polarized light, the 1/4 wave plate 641 is disposed with attention to the optical axis direction, and the optical axis of the 1/4 wave plate 641 should have an included angle of 45 degrees with the polarization directions of the two linearly polarized light beams. In this way, the polarization component of this embodiment rotates the linear polarization direction of one beam of light by 90 ° by using the 1/2 wave plate 643, the polarization state of the other beam of light is unchanged after passing through the optical path compensation window 642, and then converts the two beams of linearly polarized light into two beams of circularly polarized light with opposite polarization directions by using the 1/4 wave plate 641, so as to form a polarized interference light field, and form a patterned light spot with a polarized structure on the substrate. In this embodiment, the 1/2 wave plate 643 is driven to translate on the transparent disk 644.

FIG. 14 shows a fifth embodiment of the optical path structure for polarized interference lithography according to the present invention. In this embodiment, the optical path structure for polarization interference lithography includes a light source module, a beam splitting component, and an imaging component connected in series on an optical path. The same contents as those of the first embodiment are not repeated, and the portions different from those of the first embodiment are described with emphasis.

In this embodiment, the polarizing component includes a 1/2 wave plate 651 and two 1/4 wave plates 652. The 1/2 wave plate 651 is provided before the spectroscopic assembly 2, and is rotatable. The two 1/4 wave plates 652 are mounted on a transparent disk 653, which form a redirecting structure (in other embodiments, the two 1/4 wave plates 652 may be mounted by other means, such as directly on a rotatable ring). Through the transparent disk 653, two 1/4 wave plates 652 are juxtaposed between the first lens group 41 and the second lens group 42, at positions corresponding to the two incident light rays, respectively. The two 1/4 wave plates 652 are orthogonal, so that the incident linear polarized light is converted into two circularly polarized light beams with opposite polarization directions after passing through the two 1/4 wave plates 652. The two 1/4 wave plates 652 can rotate around the center of the optical path through the rotation of the transparent disc 6), the rotation of the 1/2 wave plates 651 and the rotation of the two 1/4 wave plates 652 are matched, the rotation of the light splitting assembly is synchronous with the rotation of the light splitting assembly, the linearly polarized light beams incident on the 1/4 wave plates always keep a fixed included angle with the optical axis of the 1/4 wave plates, the linearly polarized light beams which pass through the light splitting assembly and are split into two beams of linearly polarized light beams are converted into two circularly polarized light beams with opposite polarization directions through the two 1/4 wave plates 652, polarized interference light fields are further formed, and pattern light spots with a polarized structure are formed on the substrate. Fig. 15 shows that in this embodiment, when the 1/2 wave plate 651 rotates, the polarization direction of the linearly polarized light beam is changed, the transparent disk 653 needs to rotate around the main optical axis as a whole, and by the movement of these two degrees of freedom, the function of rotating the two linearly polarized light beams emitted from the beam splitting assembly around the optical axis can be matched, so that the linearly polarized light beam incident on the 1/4 wave plate 652 always maintains a fixed included angle with the optical axis of the wave plate.

FIG. 16 illustrates an embodiment of a polarized interference lithography system according to the present invention, and FIG. 17 illustrates an embodiment of a distribution structure of polarization patterns obtained under a polarized interference lithography system.

In this embodiment, the polarization interference lithography system includes an optical path structure, an optical path adjusting and controlling component, a motion platform, an electronic control system, control software, and an equipment mechanism frame.

The light path regulating component is connected with the light path structure and used for regulating and controlling the movement of the polarization component (such as the rotation movement of the polarization device), the movement of the light splitting component (such as the rotation and translation movement of the light splitting device) and the movement of the imaging component (such as the focusing movement of the optical lens).

The motion platform carries the photoetching substrate and enables the photoetching substrate to move on an XY axis so as to realize transverse pattern splicing. The motion platform is one of important factors influencing the pattern splicing precision, and the motion platform configuration can comprise a low expansion coefficient objective table, a high-resolution laser interferometer and the like in combination with the precision requirement of the polarization optical device.

The mechanical frame of the apparatus is used for bearing the optical machine component of the lithography system and providing a stable internal environment of the apparatus for the optical machine component, and may comprise a granite framework, a vibration isolation system, an internal air purification system, a temperature control system and the like.

The electric control system is connected with the light path regulating and controlling component and the motion platform, and the light path regulating and controlling component and the motion platform are controlled by combining the control software. The electronic control system may include various electrical components such as motion controllers, drivers, IO cards, power supplies, computers, and the like. The control software is used for reading the computer data, comprehensively regulating and controlling the light path components, the motion platform and the like, and completing the exposure of the graph.

The lithography system can automatically expose the photo-alignment material according to the computer definition data of the polarization structure, control the beam splitting component and the polarization component through high-precision mechanical, control and other technologies, adjust the period, orientation and other parameters of the polarization structure in the light field, perform photochemical action with the polarization sensitive material to form specific polarization pattern distribution, control the coordinate displacement of the polarization light field parameter and the substrate according to a predefined polarization pattern design file by the polarization lithography system, perform light field effective splice lithography, and form the expected polarization pattern distribution on the lithography substrate, for example, as shown in fig. 17, an embodiment of a distribution structure of the polarization pattern obtained under the polarization interference lithography system is shown. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity. It will be understood that when an element such as a layer, region or substrate is referred to as being "formed on," "disposed on" or "located on" another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly formed on" or "directly disposed on" another element, there are no intervening elements present.

In this document, the use of the ordinal adjectives "first", "second", etc., to describe an element, is merely intended to distinguish between similar elements, and does not necessarily imply that the elements so described must be in a given sequence, or a temporal, spatial, hierarchical, or other limitation.

In this document, unless otherwise indicated, the meaning of "a plurality", "a number" is two or more.

It will be appreciated by those of ordinary skill in the art that all or part of the steps of implementing the above-described method embodiments may be implemented by hardware associated with program instructions, and the above-described program may be stored in a computer readable storage medium, which when executed, performs the steps comprising the above-described method embodiments. The aforementioned storage medium includes: various media that can store program code, such as ROM, RAM, magnetic or optical disks.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

In this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a list of elements is included, and may include other elements not expressly listed.

The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (10)

1. The light path structure for polarization interference lithography is characterized by comprising a light source module, a polarization component, a light splitting component and an imaging component which are connected in series on a light path; the light source module is used for generating a linearly polarized light beam with coherent characteristics; the light splitting assembly is used for splitting the injected light into two beams of light and emitting the two beams of light to the imaging assembly, the included angle of the two beams of light is variable and the two beams of light can rotate around the optical axis of the incident light, and the imaging assembly is used for converging the two beams of light on the surface of the photoetching substrate; the light splitting component is matched with the polarizing component and used for carrying out optical modulation on linearly polarized light, so that when a light beam reaches a photoetching substrate, the light beam is two circularly polarized lights with opposite polarization directions, and a polarized interference light field is formed.

2. The optical path structure of claim 1, wherein the polarized interference light field is capable of forming a light spot with a linear polarization pattern whose direction is periodically changed on the surface of the photolithographic substrate, the period of the linear polarization pattern is changed by changing the included angle of two light beams reaching the surface of the photolithographic substrate by using the polarization component, the light splitting component and the imaging component, and the orientation of the linear polarization pattern is changed by changing the included angle of the plane of the two light beams and the X-axis on the XY coordinate system of the surface of the photolithographic substrate.

3. The optical path structure of claim 1, wherein the light splitting assembly comprises a light splitting element and/or a 4f optical element that is rotatable and axially movable about the optical axis to achieve continuous change in the angle of the outgoing light beam and rotation about the optical axis.

4. The optical path structure of claim 1 wherein the imaging assembly comprises a first optical lens group and a second optical lens group, the first lens group and the second lens group being an infinity optical path therebetween.

5. The optical path structure of claim 1 wherein the polarizing component comprises a 1/4 wave plate, an optical path compensation window, a 1/2 wave plate; the 1/4 wave plate is arranged in front of the light splitting component and is used for converting linearly polarized light into circularly polarized light; the optical path compensation window and the 1/2 wave plate are arranged between the first lens group and the second lens group in parallel, the positions of the optical path compensation window and the 1/2 wave plate correspond to the two incident light beams respectively, and the optical path compensation window is used for matching the optical path difference of the two light beams; the 1/2 wave plate is used for reversing the polarization direction of the incident circularly polarized light; the optical path compensation window and the 1/2 wave plate can rotate around the center of the optical path and synchronously rotate with the light splitting assembly so as to keep the positions of the optical path compensation window and the 1/2 wave plate corresponding to the two incident light beams respectively, so that after passing through the 1/4 wave plate and the light splitting assembly, circularly polarized light which is split into two beams passes through the 1/2 wave plate and the optical path compensation window respectively to become circularly polarized light with opposite polarization directions.

6. The optical path structure of claim 1, wherein the polarization component comprises two 1/4 wave plates, and the two 1/4 wave plates are arranged between the first lens group and the second lens group in parallel, and the positions of the two wave plates respectively correspond to the two incident light beams; when the light splitting assembly rotates, the two 1/4 wave plates can synchronously rotate around the center of the light path, the two 1/4 wave plates are orthogonal and respectively translate on the circumference, so that the included angle between the optical axes of the two 1/4 wave plates and the polarization direction of incident ray polarized light is kept unchanged, the light is split into two linearly polarized light beams after passing through the light splitting assembly, and the two linearly polarized light beams are converted into two circularly polarized light beams with opposite polarization directions after passing through the two 1/4 wave plates.

7. The optical path structure of claim 1, wherein the polarizing component comprises a 1/4 wave plate, an optical path compensation window, and a 1/2 wave plate, the 1/4 wave plate, the optical path compensation window, and the 1/2 wave plate being disposed between the first lens group and the second lens group; the optical path compensation window and the 1/2 wave plate are arranged between the first lens group and the second lens group in parallel, the optical path compensation window is used for matching the optical path difference of two light beams, and the 1/2 wave plate is used for reversing the polarization direction of the incident circularly polarized light; the 1/4 wave plate is arranged in front of the optical path compensation window and the 1/2 wave plate and is used for converting linearly polarized light into two circularly polarized light beams with the same polarization direction; the optical path compensation window and the 1/2 wave plate are respectively corresponding to the two incident light beams, and when the light splitting assembly rotates, the optical path compensation window and the 1/2 wave plate can synchronously rotate around the center of the optical path so as to keep the positions of the optical path compensation window and the 1/2 wave plate to respectively correspond to the two incident light beams, so that after the optical splitting assembly and the 1/4 wave plate pass through the light splitting assembly, two circularly polarized lights with the same polarization direction respectively pass through the 1/2 wave plate and the optical path compensation window to form two circularly polarized lights with opposite polarization directions.

8. The optical path structure of claim 1, wherein the polarizing component comprises a 1/4 wave plate, an optical path compensation window, and a 1/2 wave plate, the 1/4 wave plate, the optical path compensation window, and the 1/2 wave plate being disposed between the first lens group and the second lens group; the optical path compensation window and the 1/2 wave plate are arranged between the first lens group and the second lens group in parallel, the optical path compensation window is used for matching the optical path difference of two light beams, the 1/2 wave plate is used for rotating the polarization direction of the incident linearly polarized light by 90 degrees, and the positions of the optical path compensation window and the 1/2 wave plate respectively correspond to the two incident light beams; the 1/4 wave plate is arranged behind the optical path compensation window and the 1/2 wave plate and is used for converting linearly polarized light into circularly polarized light; when the light splitting assembly rotates, the optical path compensation window and the 1/2 wave plate can synchronously rotate around the center of the optical path, and meanwhile, the 1/2 wave plate moves horizontally on the circumference, so that an included angle between the linear polarization direction of the incident light and the optical axis direction of the 1/2 wave plate is kept unchanged, and two beams of light pass through the 1/4 wave plate to form two beams of circularly polarized light with opposite polarization directions.

9. The optical path structure of claim 1, wherein the polarizing component comprises a 1/2 wave plate and two 1/4 wave plates; the 1/2 wave plate is arranged in front of the light splitting component; the two 1/4 wave plates are arranged between the first lens group and the second lens group in parallel, the positions of the two 1/4 wave plates respectively correspond to the two incident light beams, the two 1/4 wave plates are orthogonal, and the incident linear polarized light is converted into two circularly polarized light beams with opposite polarization directions after passing through the two 1/4 wave plates; the 1/2 wave plate can rotate, the two 1/4 wave plates can rotate around the center of the optical path, the rotation of the 1/2 wave plate and the two 1/4 wave plates is matched with the rotation of the light splitting assembly, the light splitting assembly rotates synchronously, the linearly polarized light beam incident on the 1/4 wave plate always keeps a fixed included angle with the optical axis of the 1/4 wave plate, the linearly polarized light beam is split into two beams of linearly polarized light after passing through the light splitting assembly, and the two beams of linearly polarized light beam are converted into two beams of circularly polarized light with opposite polarization directions after passing through the two 1/4 wave plates.

10. A polarization interference lithography system, comprising the optical path structure according to any one of claims 1 to 9, and further comprising an optical path regulating component, a motion platform, an electronic control system, and control software, wherein the optical path regulating component is connected to the optical path structure, and is used for regulating and controlling motions of the polarization component, the beam splitting component, and the imaging component; the motion platform carries the photoetching substrate and enables the photoetching substrate to move on an XY axis so as to realize transverse pattern splicing; the electric control system is connected with the light path regulating and controlling component and the motion platform, and the light path regulating and controlling component and the motion platform are controlled by combining the control software.