Plasmonic lithographic imaging method and apparatus, and computer-readable medium

Abstract

A plasmonic lithographic imaging method and apparatus, and a computer-readable medium. The plasmonic lithographic imaging method comprises: acquiring an axial direction of an imaging structure of plasmonic lithographic imaging, wherein the imaging structure comprises a plurality of mask patterns which are arranged in a one-dimensional periodic array; and light irradiating the plurality of mask patterns in the one-dimensional periodic array in a target direction which forms a preset off-axis angle with respect to the axial direction, so as to obtain a plasmonic lithographic image corresponding to the plurality of mask patterns in the one-dimensional periodic array. By means of irradiating the mask patterns in the target direction at the preset off-axis angle, the diffraction order of light can be affected, such that the transmission efficiency of light in a forbidden pitch range is improved, thereby increasing the contrast of the light intensity of the mask patterns in the forbidden pitch range during imaging, and ultimately realizing the exposure imaging of the mask patterns in the forbidden pitch range.

Description

Plasma lithography imaging method, device and computer readable medium

[0001] The present application claims priority to the Chinese patent application No. 202411315589.4, filed on September 20, 2024, and entitled "Plasma lithography imaging method, device and computer readable medium", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of semiconductor, in particular to a plasma lithography imaging method, device and computer readable medium. BACKGROUND

[0003] With the development of semiconductor related technology, the lithography technology, which is one of the important technologies for manufacturing semiconductor devices, is also developing rapidly. As a supplement to mainstream lithography technology, the plasma lithography technology is very different from traditional optical lithography technology, such as deep ultraviolet lithography (DUVL) and extreme ultraviolet lithography (EUVL).

[0004] The plasma lithography technology can break through the diffraction limit in traditional lithography by using evanescent near-field imaging containing high frequency information. Experiments have shown that even if a light source with a wavelength of 365 nanometers (nm) is used, the resolution can reach about 20 nm under single exposure conditions, which is about 1 / 17 of the light wavelength, and can be further improved. This method provides a reliable technical approach for the study of low-cost, large-area and high-efficiency lithography technology, and therefore has received extensive attention.

[0005] However, the current plasma lithography technology has a forbidden period problem, that is, the contrast of light intensity of the mask pattern in the forbidden period range is very small when imaging, and the photoresist pattern of the mask pattern in the forbidden period range cannot be exposed. SUMMARY

[0006] Therefore, the purpose of the present application is to provide a plasma lithography imaging method, device and computer readable medium, which can increase the contrast of light intensity of the mask pattern in the forbidden period range when imaging, and realize the exposure imaging of the mask pattern in the forbidden period range.

[0007] To achieve the above purpose, the present application has the following technical solutions:

[0008] The present application provides a plasma lithography imaging method, comprising:

[0009] an axial direction of an imaging structure of plasma lithography imaging, the imaging structure comprising a plurality of mask patterns in one-dimensional periodic variation;

[0010] a target direction of a light ray irradiating the plurality of mask patterns in one-dimensional periodic variation at a preset off-axis angle with the axial direction, to obtain plasma lithography imaging corresponding to the plurality of mask patterns in one-dimensional periodic variation.

[0011] Optionally, the number of light sources emitting the light ray is 2, and the 2 light sources are axisymmetric or center-symmetric based on the axial direction.

[0012] Optionally, a line connecting the 2 light sources is perpendicular to an extension direction of the plurality of mask patterns in one-dimensional periodic variation.

[0013] Optionally, as the off-axis angle increases, the contrast of the plasma lithography imaging corresponding to the plurality of mask patterns in one-dimensional periodic variation first increases and then decreases.

[0014] Optionally, the absolute value of the off-axis angle is greater than 0° and less than 90°.

[0015] Optionally, the off-axis angle at which the contrast of the plasma lithography imaging corresponding to the plurality of mask patterns in one-dimensional periodic variation is the largest is 40°.

[0016] Optionally, the contrast of the plasma lithography imaging corresponding to the plurality of mask patterns in one-dimensional periodic variation is greater than a contrast threshold.

[0017] Optionally, the contrast threshold is 0.4.

[0018] The present application provides a plasma lithography imaging device, comprising:

[0019] an acquisition unit configured to acquire an axial direction of an imaging structure of plasma lithography imaging, the imaging structure comprising a plurality of mask patterns in one-dimensional periodic variation;

[0020] an irradiation unit configured to irradiate the plurality of mask patterns in one-dimensional periodic variation with a light ray at a target direction of a preset off-axis angle with the axial direction, to obtain plasma lithography imaging corresponding to the plurality of mask patterns in one-dimensional periodic variation.

[0021] The present application provides a computer readable medium comprising instructions which, when executed on a computer, cause the computer to perform the method described above.

[0022] The application provides a kind of plasma lithography imaging method, comprising: obtaining the axial direction of the imaging structure of plasma lithography imaging, the imaging structure includes a plurality of mask patterns that are one-dimensional periodic variation, light is irradiated to a plurality of mask patterns that are one-dimensional periodic variation with the target direction of pre-set off-axis angle with axial direction, obtains the plasma lithography imaging corresponding to a plurality of mask patterns that are one-dimensional periodic variation.That is, the application can affect the diffraction order of light by irradiating mask pattern with the target direction of pre-set off-axis angle, to improve the transmission efficiency of light in forbidden period range, to improve the contrast of light intensity of mask image in forbidden period range when imaging, finally realize the exposure imaging of mask pattern in forbidden period range. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0024] Fig. 1 shows a kind of imaging structure of plasma lithography imaging structure schematic diagram;

[0025] Fig. 2 shows a kind of plasma lithography imaging method provided by the application flow schematic diagram;

[0026] Fig. 3 shows a kind of light irradiation imaging structure schematic diagram provided by the application;

[0027] Fig. 4 shows a kind of optical transfer function curve and the corresponding relationship of diffraction order schematic diagram provided by the application;

[0028] Fig. 5 shows a kind of light intensity contrast changes with period curve schematic diagram provided by the application under different off-axis angles;

[0029] Fig. 6 shows a kind of contrast changes with off-axis angle relationship schematic diagram provided by the application;

[0030] Fig. 7 shows a kind of plasma lithography imaging device structure schematic diagram provided by the application. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings.

[0032] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced without the specific details. In other instances, well-known methods have not been described in detail in order not to unnecessarily obscure aspects of the present application.

[0033] The present application is described in detail below with reference to the accompanying drawings. In the description below, for the purpose of explanation, the drawings show the specific embodiments in which the application is applied. The drawings are schematic representations and so the proportions of the various components in the drawings are not necessarily to scale. Moreover, the drawings are presented in a simplified manner in order to make the drawings more understandable. In actual production, three-dimensional spatial dimensions of length, width and depth should be included.

[0034] With the development of semiconductor-related technologies, one of the important technologies for manufacturing semiconductor devices, lithography technology, is also developing rapidly. As a supplement to mainstream lithography technology, plasmonic lithography technology is very different from traditional optical lithography technology, such as deep ultraviolet lithography (DUVL) and extreme ultraviolet lithography (EUVL).

[0035] Plasmonic lithography, also known as surface plasmon lithography (Surface plasmon lithography) technology, is a lithography technology that resonantly amplifies the evanescent wave at the object (mask) and participates in imaging by exciting surface plasmon polaritons (SPPs) or localized surface plasmons on the surface of the metal and dielectric, so that the photoresist can be exposed and imaged, and finally the pattern transfer is realized.

[0036] Plasmonic lithography technology can break through the diffraction limit in traditional lithography by using evanescent near-field imaging containing high-frequency information. Experiments have shown that even if a light source with a wavelength of 365 nanometers (nm) is used, the resolution can reach about 20 nm under single exposure conditions, which is about 1 / 17 of the light wavelength, and can be further improved. This method does not need to introduce complex and expensive optical lenses and short-wavelength light sources, and is compatible with traditional lithography materials and processes, and has gradually developed into a new nanophotonic processing technology with high resolution and low cost.

[0037] The plasma lithography mainly includes plasma imaging lithography, interference lithography and direct writing lithography. The direct writing lithography generally has no imaging structure, and the imaging lithography and the interference lithography have imaging structures including mask patterns. Referring to FIG. 1, the imaging structure is a single-layer metal film superlens structure, which includes glass, a mask pattern, polymethyl methacrylate (PMMA), a metal film, photoresist (PR) and a reflective layer which are stacked in sequence. The stacking direction is denoted as the z direction, and the above-mentioned film layers extend along the x direction which is perpendicular to the z direction. The mask pattern is, for example, a chromium (Cr) mask, the metal film is, for example, silver (Ag), and the reflective layer is, for example, silver.

[0038] The imaging process of the plasma lithography including the imaging structure is roughly as follows: a light source is incident on the mask pattern through the glass to produce various diffraction orders, including low-frequency transmission waves and high-frequency evanescent waves. These diffraction light waves continue to propagate through the single-layer metal film behind the mask pattern until the photoresist layer, so as to transfer the information of the mask pattern to the photoresist to obtain a photoresist image. In the process of transferring the diffraction orders to the photoresist, if the wave vector of the high-frequency evanescent diffraction order matches the wave vector of the surface plasmon polariton at the metal / dielectric interface, the surface plasmon polariton can be excited at the metal / dielectric interface, so that the high-frequency evanescent wave is resonantly amplified and transmitted to the photoresist layer, thereby realizing the improvement of the lithography resolution, that is, the metal / dielectric interface acts as an imaging system. In addition, a reflective layer is often placed behind the photoresist layer to further improve the imaging effect of the photoresist layer through the reflection resonance effect.

[0039] However, the current plasma lithography technology has a forbidden pitch problem, that is, there is a problem that the contrast of light intensity of the mask pattern in the forbidden pitch range is very small during imaging, and the photoresist pattern of the mask pattern in the forbidden pitch range cannot be exposed. Even if there is a mask pattern in the forbidden pitch range in the layout design, manufacturing cannot be realized, so the function required by the layout design cannot be completed.

[0040] Based on this, the application provides a kind of plasma lithography imaging method, comprising: the axial direction of the imaging structure of plasma lithography imaging is acquired, the imaging structure includes a plurality of mask patterns that are one-dimensional periodic variation, light is irradiated to a plurality of mask patterns that are one-dimensional periodic variation with the target direction of preset off-axis angle with axial direction, obtains the plasma lithography imaging corresponding to a plurality of mask patterns that are one-dimensional periodic variation.That is to say, the application can affect the diffraction order of light by irradiating mask pattern with the target direction of preset off-axis angle, to improve the transmission efficiency of light in forbidden period range, to improve the contrast of light intensity of mask image in forbidden period range when imaging, finally realize the exposure imaging of mask pattern in forbidden period range.

[0041] In order to better understand the technical scheme and technical effects of the application, specific embodiments will be described in detail below with reference to the drawings.

[0042] Referring to Fig. 2, a flow chart of a plasma lithography imaging method provided by an embodiment of the application is shown, and the method comprises the following steps:

[0043] S101, the axial direction of the imaging structure of plasma lithography imaging is acquired, and the imaging structure includes a plurality of mask patterns that are one-dimensional periodic variation.

[0044] In the embodiments of the application, the imaging structure of plasma lithography imaging has multiple, and the imaging structure can be acquired, wherein the imaging structure includes a plurality of mask patterns that are one-dimensional periodic variation, so that plasma lithography imaging can be performed according to the mask pattern.

[0045] As an example, the imaging structure is a single-layer metal thin film superlens structure, which includes glass, mask pattern, polymethyl methacrylate (PMMA), metal thin film, photoresist (PR) and reflective layer stacked in sequence, wherein the mask pattern is, for example, chromium (Cr) mask, the metal thin film is, for example, silver (Ag), and the reflective layer is, for example, silver.

[0046] In the embodiments of the application, the axial direction of the imaging structure can also be acquired, so as to subsequently determine the target direction of light irradiating the mask pattern according to the axial direction of the imaging structure.

[0047] As an example, referring to Fig. 3, a schematic diagram of light irradiating the imaging structure is provided by an embodiment of the application, and the imaging structure in Fig. 3 is a cross-sectional schematic diagram, and the dashed line direction in Fig. 3 is the axial direction of the imaging structure.

[0048] S102, the light rays irradiate the plurality of mask patterns with a one-dimensional periodic variation in a target direction with a preset off-axis angle from the axial direction to obtain plasma lithography imaging corresponding to the plurality of mask patterns with a one-dimensional periodic variation.

[0049] In the embodiments of the present application, considering that the current light rays irradiate the imaging structure at a normal incidence angle, the imaging structure is irradiated at the normal incidence angle, which causes the contrast of light intensity of the mask patterns in the forbidden period range to be low during imaging, and the mask patterns cannot be imaged. At this time, the light rays can irradiate the plurality of mask patterns with a one-dimensional periodic variation in a target direction with a preset off-axis angle from the axial direction to obtain plasma lithography imaging corresponding to the plurality of mask patterns with a one-dimensional periodic variation. That is, the light rays with the preset off-axis angle from the axial direction can be used to irradiate the mask patterns, that is, the off-axis illumination is used, so as to improve the contrast of light intensity of the mask patterns in the forbidden period range during imaging.

[0050] Referring to FIG. 3, the off-axis angle can be represented by θ. The mask pattern is represented by mask. The lens is represented by lens. FIG. 3 schematically shows that the light rays irradiate the imaging structure in a target direction with a preset off-axis angle θ from the axial direction.

[0051] Theoretical analysis is made below by combining the optical transfer function (OTF) curve of the plasma lithography imaging system and the diffraction order characteristics of the light rays when the light rays are obliquely incident, to prove that the off-axis illumination can improve the contrast of imaging and solve the problem of the forbidden period in the plasma lithography.

[0052] Referring to FIG. 4, FIG. 4 is a schematic diagram of the correspondence between the optical transfer function curve and the diffraction order provided in the embodiments of the present application. The four curves in FIG. 4 are the optical transfer function characteristic curves of the plasma imaging lithography system based on the imaging structure when TM waves (the magnetic field component Hy is perpendicular to the incident plane) are incident, and line 1, line 2, line 3 and line 4 represent the Hy component, the Ex component, the Ez component and the total electric field intensity E in turn, which can be obtained by the transfer matrix method.

[0053] The spatial frequency expression of the diffraction order generated when the light rays are incident on the mask patterns with a one-dimensional periodic variation of the imaging structure is shown in the following formula.

[0054] k0= 2π / λ;

[0055] wherein m=0, ±1, ±2, …, m is the diffraction order of the mask pattern, n is the refractive index of the incident medium, θ is the incidence angle, p is the period of the mask pattern, and λ is the wavelength of the light rays.

[0056] The reason for the problem of the forbidden period is that the high-frequency diffraction order kx fall into the ±nk0 region shown by points B and B' in FIG. 4, and the solid arrows at points B and B' in FIG. 4 represent the positions of the high-frequency diffraction orders k x of the mask pattern. At this time, the transfer efficiency of the imaging system for these orders is extremely low, and thus the contrast of the imaging is extremely poor, and the forbidden period phenomenon occurs.

[0057] According to the above equation, the spatial frequency of the diffraction order is related to not only the period of the mask pattern but also the incident angle θ, which is the reason why the forbidden period problem can be improved or even solved by off-axis illumination. As shown by the dashed arrows in FIG. 4, when off-axis illumination is used, the diffraction orders will be shifted to the right as a whole (similarly, if the direction of the incident angle is opposite, the diffraction orders will be shifted to the left as a whole). The movement of the diffraction orders makes the high-frequency diffraction orders no longer located in the ±nk0 region shown by points B and B', where the transfer efficiency is extremely low.

[0058] Specifically, the +1 order enters the evanescent wave band, the transfer efficiency is improved, and even the resonance of the surface plasmon polariton corresponding spatial frequency (k spp ) is achieved; the -1 order enters the transmission wave band, and the transfer efficiency is also improved. After the movement of the 0 order, the transfer efficiency is reduced but still in the transmission wave band. According to the Fourier optics theory, the reduction of the proportion of the 0 order and the increase of the proportion of the high-frequency order are both beneficial to improve the contrast of the imaging, because the high-frequency order contains the detail information of the object (mask pattern) to be imaged. In addition, the use of off-axis illumination also has the benefit that the asymmetry of the diffraction orders makes the positive and negative diffraction orders of the same order not fall into the B and B' regions with extremely low transfer efficiency at the same time, so that the minimum contrast is larger than that of the normal incidence.

[0059] That is, by irradiating the mask pattern with a target direction of a preset off-axis angle, the present application can affect the diffraction orders of the light, thereby improving the transfer efficiency of the light in the forbidden period range, improving the contrast of the light intensity of the mask image in the forbidden period range during imaging, and ultimately achieving the exposure imaging of the mask pattern in the forbidden period range.

[0060] In the embodiments of the present application, considering that a plurality of mask patterns are one-dimensionally periodically varied and the symmetry during the manufacture of the patterns, symmetric two light sources are usually used for light irradiation, that is, the number of light sources emitting light is two, and the two light sources can be axisymmetric or centrosymmetric based on the axial direction.

[0061] Referring to FIG. 3, two source points are shown, and the positions of the source points are the focus plane. The light rays of the two light sources are incident on the mask pattern in the target directions with off-axis angles of -θ and θ, respectively, with respect to the axial direction. The imaging results of the two symmetrically incident plane waves are incoherently superimposed, and the final light intensity distribution is obtained.

[0062] Specifically, to maximize the improvement of the contrast of the imaging, the line connecting the two light sources can be perpendicular to the extension direction of the plurality of mask patterns that vary periodically in one dimension, thereby further improving the imaging effect. Referring to FIG. 3, the line connecting the two light sources is not only perpendicular to the extension direction of the plurality of mask patterns that vary periodically in one dimension, but also perpendicular to the axial direction.

[0063] In the embodiments of the present application, considering the case with two light sources, the two light sources are symmetrically arranged, the absolute values of the off-axis angles are the same, but the positive and negative of the off-axis angles represent different target directions. Taking the axial direction as the starting direction, the greater the absolute value of the off-axis angle away from the axial direction. Considering that the contrast of the imaging needs to be improved by off-axis illumination, the absolute value of the off-axis angle is greater than 0° and less than 90°.

[0064] In the embodiments of the present application, the off-axis illumination can improve the contrast of the plasma lithography imaging. Specifically, the contrast of the plasma lithography imaging corresponding to the plurality of mask patterns that vary periodically in one dimension is greater than a contrast threshold. That is, the off-axis illumination can at least improve the contrast of the plasma lithography imaging to be greater than the contrast threshold, thereby achieving that the plurality of off-axis angles in the forbidden period range can have good imaging effects.

[0065] As an example, the contrast threshold is 0.4.

[0066] Next, the imaging structure shown in FIG. 1, which is the most representative in plasma imaging lithography, is selected for simulation experiment verification, and the improvement degree of the contrast of the mask pattern in the forbidden period range by the off-axis illumination of the two light sources is quantitatively demonstrated.

[0067] The imaging structure shown in Fig. 1 and the most obvious bright field mask (the light-transmitting part is larger than the non-light-transmitting part) of the forbidden period problem are taken as the simulation imaging structure. Two light sources of normal incidence on-axis illumination and off-axis angles θ of 20°, 30°, 40°, 50°, 60° and 80° are taken as the illumination light source respectively, and the contrast curve of the photoresist spatial image light intensity of the through pitch is obtained as shown in Fig. 5, that is, the contrast with different pitches is shown in Fig. 5. Among them, the polarization of the light source is TM polarization, and the imaging plane is the most commonly used middle plane of the photoresist layer. The line 1, line 2, line 3, line 4, line 5, line 6 and line 7 in Fig. 5 are the curve diagrams of normal incidence on-axis illumination and off-axis angles θ of 0°, 20°, 30°, 40°, 50°, 60° and 80° respectively.

[0068] The formula of the contrast curve of the photoresist spatial image light intensity in Fig. 5 is as follows.

[0069] From the qualitative point of view, first of all, the off-axis illumination has a very significant effect on the light intensity contrast. Compared with the normal incidence on-axis illumination, the light intensity contrast is improved to different degrees under each off-axis illumination condition. Secondly, although the off-axis illumination improves the contrast to different degrees, the contrast at each off-axis angle still fluctuates with the change of the period (pitch). There are peak values of the contrast at some periods, and there are valley values of the contrast at some periods, but basically they are above the contrast threshold value 0.4. Therefore, the off-axis illumination can indeed greatly improve the contrast of the mask pattern of different periods, effectively improving and solving the forbidden period problem.

[0070] In the embodiments of the present application, different off-axis angles have different effects on the contrast of imaging. With the increase of the off-axis angle, the contrast of the plasma lithography imaging corresponding to the plurality of mask patterns with one-dimensional periodicity first increases and then decreases.

[0071] As shown in the OTF curve in Fig. 4, taking the example of the right shift of the diffraction order caused by the illumination of the imaging structure at the tilt angle, with the increase of the tilt angle, the dashed arrow at point B moves to the right, and its transfer efficiency reaches the k spp value corresponding to point A, and then starts to decrease. At this time, its transfer efficiency decreases, so the contrast improvement effect first increases and then decreases with the increase of the off-axis angle.

[0072] From the quantitative point of view, the contrast calculation value (post-contrast) of different off-axis angles θ can be calculated, the contrast calculation value including the mean-contrast of through pitch, the mean-contrast-t of forbidden period, and the maximum contrast (max-contrast) and the minimum contrast (min-contrast) under the illumination of different off-axis angles are found. Referring to FIG. 6, a schematic diagram of the change relationship between the contrast and the off-axis angle is provided in the embodiment of the present application, that is, FIG. 6 is a schematic diagram of the contrast calculation value (post-contrast with different θ) under different off-axis angles, wherein the line 1, the line 2, the line 3 and the line 4 of the four curves are the mean-contrast of through pitch, the mean-contrast-t of forbidden period, the maximum contrast and the minimum contrast respectively. The change trend of the four curves is first increasing and then decreasing instead of monotonously increasing, which indicates that there is an optimal off-axis angle in the off-axis angle change interval of 0 to 90°, and the optimal off-axis angle shown in FIG. 6 is 40°, that is, the off-axis angle corresponding to the maximum contrast of the plasma lithography imaging of the plurality of mask patterns with one-dimensional periodicity is 40°. In the whole period range, the mean-contrast is 0.4424 when the off-axis angle is 0° (that is, under the on-axis normal incidence), and the mean-contrast is 0.7318 when the off-axis angle is 40°, and the mean-contrast is improved by 65.42%. The mean-contrast-t of forbidden period is 0.3577 under the on-axis normal incidence, and the mean-contrast-t of forbidden period is 0.7545 when the off-axis angle is 40°, and the mean-contrast-t of forbidden period is improved by 110.93%. Except that the minimum contrast is less than the threshold value 0.4 when the off-axis angle is 80°, the maximum contrast and the minimum contrast of the rest off-axis angles are all above the threshold value 0.4, which meets the contrast requirement of exposure. Therefore, from the quantitative point of view, the optimal off-axis angle is found, which can maximize the contrast of through pitch or forbidden period, and solves the forbidden period problem.

[0073] In practical applications, the optimal off-axis angle of the off-axis illumination is related to the parameters of the imaging structure, and if the parameters of the imaging structure change, the optimal off-axis angle can also change.

[0074] It can be seen that the plasma lithography imaging method provided in the embodiment of the present application solves the forbidden period problem in the plasma lithography by adopting the off-axis illumination mode, and gives the reason analysis combined with the OTF curve, so that the contrast of the mask pattern in the originally forbidden period range is greatly improved and meets the requirement of exposure on the contrast, to complete the demand of design pattern manufacturing, and provides conditions for better development of the plasma lithography technology.

[0075] Based on the plasma lithography imaging method provided in the above embodiments, the embodiments of the present application further provide a plasma lithography imaging device. Referring to FIG. 7, a structural schematic diagram of a plasma lithography imaging device provided in the embodiments of the present application is shown. The plasma lithography imaging device 700 provided in the embodiments of the present application includes:

[0076] An acquisition unit 710 is configured to acquire an axial direction of an imaging structure of plasma lithography imaging, the imaging structure including a plurality of mask patterns that are one-dimensionally periodically varied;

[0077] An irradiation unit 720 is configured to irradiate the plurality of mask patterns that are one-dimensionally periodically varied with light rays in a target direction that is a preset off-axis angle from the axial direction, to obtain plasma lithography imaging corresponding to the plurality of mask patterns that are one-dimensionally periodically varied.

[0078] In some embodiments, the number of light sources emitting the light rays is 2, and the 2 light sources are axially symmetric or centrally symmetric based on the axial direction.

[0079] In some embodiments, a line connecting the 2 light sources is perpendicular to an extension direction of the plurality of mask patterns that are one-dimensionally periodically varied.

[0080] In some embodiments, as the off-axis angle increases, the contrast of the plasma lithography imaging corresponding to the plurality of mask patterns that are one-dimensionally periodically varied first increases and then decreases.

[0081] In some embodiments, the absolute value of the off-axis angle is greater than 0° and less than 90°.

[0082] In some embodiments, the off-axis angle at which the contrast of the plasma lithography imaging corresponding to the plurality of mask patterns that are one-dimensionally periodically varied is the largest is 40°.

[0083] In some embodiments, the contrast of the plasma lithography imaging corresponding to the plurality of mask patterns that are one-dimensionally periodically varied is greater than a contrast threshold.

[0084] In some embodiments, the contrast threshold is 0.4.

[0085] Based on the plasma lithography imaging method provided in the above embodiments, the embodiments of the present application further provide a plasma lithography imaging device, which includes:

[0086] A processor and a memory, the number of processors can be one or more. In some embodiments of the present application, the processor and the memory can be connected through a bus or other means.

[0087] The memory can include a read-only memory and a random access memory, and provide the processor with instructions and data. A portion of the memory can also include a NVRAM. The memory stores operating systems and operating instructions, executable modules or data structures, or subsets thereof, or expanded sets thereof, wherein the operating instructions can include various operating instructions for implementing various operations. The operating system can include various system programs for implementing various basic services and processing hardware-based tasks.

[0088] The processor controls the operation of the terminal device, and can also be referred to as a CPU.

[0089] The method disclosed in the embodiments of the present application can be applied to a processor or implemented by a processor. The processor can be an integrated circuit chip with a signal processing capability. In the implementation process, each step of the above method can be completed by an integrated logic circuit or an instruction in the form of software in the processor. The processor mentioned above can be a general processor, a DSP, an ASIC, an FPGA, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. Each method, step and logic block diagram disclosed in the embodiments of the present application can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as a hardware code processor for execution, or a combination of hardware and software modules in the code processor for execution. The software module can be located in a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically erasable programmable memory, a register, or other mature storage media in the art. The storage medium is located in the memory, and the processor reads the information in the memory and combines the hardware to complete the steps of the above method.

[0090] The embodiments of the present application also provide a computer readable medium for storing program codes, the program codes being used to execute any one of the methods of the above various embodiments.

[0091] In the context of this application, a computer readable medium can be a tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device. The computer readable medium can be a computer readable signal medium or a computer readable storage medium. The computer readable medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium can include, but are not limited to, an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0092] Note that the computer readable medium described above in this application can be a computer readable signal medium or a computer readable storage medium or any combination thereof. The computer readable storage medium, for example, can be, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium can include, but are not limited to, an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In this application, the computer readable storage medium can be any tangible medium that contains or stores a program for use by or in connection with an instruction execution system, apparatus, or device. In this application, the computer readable signal medium can include a computer readable program code propagated in or on a carrier wave, in baseband signal, or using any suitable medium, including but not limited to wireless, wireline, optical, infrared, or semiconductor systems. The computer readable medium can also be any computer readable medium other than a computer readable storage medium that can send, receive, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer readable medium can be transmitted using any suitable medium, including but not limited to wire, cable, fiber optic, RF, etc., or any suitable combination of the foregoing.

[0093] The computer readable medium described above can be contained in the electronic device described above; or can exist separately and not be assembled into the electronic device.

[0094] The various embodiments described in this specification are presented by way of example, and each embodiment is not necessarily composed of all features described. Each embodiment describes a different set of features, and the application can include a single embodiment or a combination of different embodiments. Each embodiment is directed to what is currently believed to be a novel and non-obvious application. In view of the many possible embodiments to which the principles of the application can be applied, it will be recognized that the embodiments described herein are shown by way of example only. Numerous changes and modifications can be made to the application as described without departing from the underlying technical concept and scope thereof.

[0095] The above description is only the preferred embodiment of the present application, although the present application has been disclosed as above with the preferred embodiment, however, it is not intended to limit the present application. Any skilled person in the art, without departing from the scope of the technical scheme of the present application, can make many possible changes and modifications to the technical content disclosed above, or modify it as equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, without departing from the content of the technical scheme of the present application, still belongs to the scope of protection of the technical scheme of the present application.

Claims

1. A method of plasma lithographic imaging, the method comprising: The application relates to a method for obtaining a plasma lithography image of an imaging structure, and a device for obtaining a plasma lithography image of an imaging structure. An axial direction of the imaging structure is obtained, the imaging structure comprising a plurality of mask patterns in one-dimensional periodic variation; Light rays are irradiated to the plurality of mask patterns in one-dimensional periodic variation at a target direction with a preset off-axis angle with the axial direction, so as to obtain a plasma lithography image corresponding to the plurality of mask patterns in one-dimensional periodic variation.

2. The method of claim 1, wherein, The number of light sources for emitting the light rays is two, and the two light sources are axisymmetric or center-symmetric based on the axial direction.

3. The method of claim 2, wherein, A line connecting the two light sources is perpendicular to an extension direction of the plurality of mask patterns in one-dimensional periodic variation.

4. The method according to any one of claims 1 to 3, characterized in that, With the increase of the off-axis angle, the contrast of the plasma lithography image corresponding to the plurality of mask patterns in one-dimensional periodic variation first increases and then decreases.

5. The method according to any one of claims 1 to 4, characterized in that, The absolute value of the off-axis angle is greater than 0 and less than 90.

6. The method of claim 5, wherein, The off-axis angle at which the contrast of the plasma lithography image corresponding to the plurality of mask patterns in one-dimensional periodic variation is the largest is 40.

7. The method according to any one of claims 1 to 6, characterized in that, The contrast of the plasma lithography image corresponding to the plurality of mask patterns in one-dimensional periodic variation is greater than a contrast threshold.

8. The method of claim 7, wherein, The contrast threshold is 0.

4.

9. A plasmonic lithographic imaging device, characterized in that, The application relates to a method for obtaining a plasma lithography image of an imaging structure, and a device for obtaining a plasma lithography image of an imaging structure. An axial direction of the imaging structure is obtained, the imaging structure comprising a plurality of mask patterns in one-dimensional periodic variation; Light rays are irradiated to the plurality of mask patterns in one-dimensional periodic variation at a target direction with a preset off-axis angle with the axial direction, so as to obtain a plasma lithography image corresponding to the plurality of mask patterns in one-dimensional periodic variation.

10. A computer readable medium characterized by The application relates to a method for obtaining a plasma lithography image of an imaging structure, and a device for obtaining a plasma lithography image of an imaging structure.

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