Method for correcting mask layout, mask and metasurface structure

Abstract

The invention provides a correction method of a mask layout, a mask and a metasurface structure. The correction method comprises the following steps: defining a rectangular coordinate system with an X axis and a Y axis which are orthogonal to each other; the correction method comprises the following steps: acquiring an initial layout, wherein the initial layout has initial patterns in one-to-one correspondence with preset micro-nano units in a target metasurface structure; according to the method, an initial pattern is corrected into a corrected pattern composed of at least one corrected rectangle, two adjacent sides of the corrected rectangle extend along an X axis and a Y axis respectively, the corrected pattern in the corrected mask layout can be compatible with layout import in a photoetching machining process, and a mask required by a photoetching process can be prepared. A target metasurface structure, such as a polarization-dependent metasurface structure, is obtained on a planar optical medium material by adopting the mask plate through a photoetching process, so that the mass production of the polarization-dependent metasurface structure is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of super surface materials, and in particular to a method for correcting a mask pattern, a mask, and a super surface structure formed by performing a photolithography process on the mask. Background Art

[0002] Polarization imaging is a new photoelectric detection method. Compared with traditional intensity imaging, polarization imaging can further obtain the polarization characteristics of the target, thereby enriching the target information. Polarization imaging has important application value in biomedicine, industrial detection, earth remote sensing, modern military, as well as marine and aviation fields.

[0003] Optical metasurface structures can arbitrarily control the phase of optical electromagnetic waves through micro-nano units etched on planar optical dielectric materials to achieve multiple functions such as deflection, focusing, polarization, and dispersion. Because metasurface structures are small in size and light in weight, they are easy to realize compact optical structures. At the same time, metasurface structures can be mass-produced at low cost through mature semiconductor production processes, providing an effective means for miniaturized and low-cost polarization imaging.

[0004] like Figure 1 As shown in the figure, most of the micro-nano units in the polarization-dependent metasurface structures are nano-fin structures with an azimuth angle θ. However, the mask layout of this structure cannot be directly used for the preparation of the mask in the lithography process, which greatly increases the data volume of the graphic file, resulting in a long layout import time, which is not conducive to the layout import in the lithography process, hindering the large-scale production of polarization-dependent metasurface structures and the development of metasurface structures in polarization imaging. Summary of the invention

[0005] The purpose of the present invention is to provide a method for correcting a mask pattern, a mask prepared based on the mask pattern corrected by the method for correcting the mask pattern, and a super surface structure formed by a photolithography process using the mask pattern.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical solution: a method for correcting a mask pattern, defining a rectangular coordinate system with orthogonal X-axis and Y-axis; the method for correcting a mask pattern comprises the following steps:

[0007] Acquire an initial layout, wherein the initial layout has an initial pattern corresponding one-to-one to a preset micro-nano unit in a target metasurface structure;

[0008] Correcting the initial figure into a corrected figure consisting of at least one corrected rectangle, wherein two adjacent sides of the corrected rectangle extend along the X axis and the Y axis respectively;

[0009] Get the vertex coordinates of the corrected shape.

[0010] As a further improved technical solution of the present invention, “correcting the initial graphic into a corrected graphic consisting of at least one corrected rectangle” specifically includes the following steps:

[0011] dividing the initial figure into at least one figure to be corrected;

[0012] Get the correction rectangle corresponding to the figure to be corrected;

[0013] The acquired correction rectangles are combined to form the correction figure.

[0014] As a further improved technical solution of the present invention, “obtaining a correction rectangle corresponding to the graphic to be corrected” specifically includes the following steps:

[0015] Obtaining a maximum inscribed rectangle of a figure to be corrected, wherein the center of the maximum inscribed rectangle overlaps with the center of the corresponding figure to be corrected, and two adjacent sides of the maximum inscribed rectangle extend along the X-axis and the Y-axis respectively;

[0016] Obtaining a minimum bounding rectangle of the figure to be corrected, wherein the center of the minimum bounding rectangle overlaps with the center of the corresponding figure to be corrected, and two adjacent sides of the minimum bounding rectangle extend along the X-axis and the Y-axis respectively;

[0017] The middle rectangle between the maximum inscribed rectangle and the minimum circumscribed rectangle is obtained, and the middle rectangle is the correction rectangle corresponding to the figure to be corrected.

[0018] As a further improved technical solution of the present invention, the center of the graphic to be corrected overlaps with the center of the corresponding correction rectangle.

[0019] As a further improved technical solution of the present invention, the ratio of the area of ​​the to-be-corrected figure to the area of ​​the corresponding correction rectangle is 0.7 to 1.3.

[0020] As a further improved technical solution of the present invention, "segmenting the initial figure into at least one figure to be corrected" specifically includes: segmenting the initial figure into at least one figure to be corrected along the direction of the initial figure.

[0021] As a further improved technical solution of the present invention, the initial figure includes a rectangle, and the quotient a and the remainder b are obtained by dividing the length of the long side of the rectangle by the length of the short side; the rectangle segmentation step "segmenting the initial figure into at least one figure to be corrected along the direction of the initial figure" specifically includes the following steps:

[0022] When b=0, the rectangle is divided into a squares along the long side direction with the short side length as the side length, and the a squares are the figure to be corrected;

[0023] When b≠0, the rectangle is divided into a squares and a rectangle along the long side direction with the short side length as the side length, and the a squares and the rectangle are the figures to be corrected.

[0024] As a further improved technical solution of the present invention, the initial figure includes an ellipse; the ellipse segmentation step of "segmenting the initial figure into at least one figure to be corrected along the direction of the initial figure" specifically includes the following steps:

[0025] Get the circumscribed rectangle of the ellipse, and divide the length of the long side of the circumscribed rectangle by the length of the short side to obtain the quotient c and the remainder d;

[0026] When d=0, the circumscribed rectangle is divided into c squares along the long side direction with the short side length of the circumscribed rectangle as the side length, and the c squares divide the initial figure into c figures to be corrected;

[0027] When d≠0, the circumscribed rectangle is divided into c squares and 1 rectangle along the long side direction with the short side length of the circumscribed rectangle as the side length. The c squares and 1 rectangle divide the ellipse into (c+1) figures to be corrected.

[0028] As a further improved technical solution of the present invention, the initial figure is a rectangle; or the initial figure is a V-shape; or the initial figure is an ellipse; or the initial figure is a ring.

[0029] As a further improved technical solution of the present invention, the initial figure is a circular ring; "correcting the initial figure into a corrected figure composed of at least one corrected rectangle" is specifically: correcting the circular ring into a corrected figure composed of a plurality of squares with the ring width of the circular ring as the side length, the center of the square is at the same distance from the inner ring of the circular ring as the distance from the outer ring, and two adjacent sides of the square extend along the X-axis and the Y-axis respectively.

[0030] As a further improved technical solution of the present invention, the ratio of the area of ​​the intersection between the initial figure and the corresponding modified figure to the area of ​​the initial figure is not less than 0.7.

[0031] As a further improved technical solution of the present invention, the ratio of the area of ​​the initial figure to the area of ​​the corresponding modified figure is 0.7 to 1.3.

[0032] As a further improved technical solution of the present invention, the absolute value of the phase difference between the phase of the preset micro-nano unit formed by the initial pattern at the position with a transmittance higher than 0.8 and the phase of the micro-nano unit formed by the corrected pattern at the position with a transmittance higher than 0.8 is not greater than 0.5 radians.

[0033] As a further improved technical solution of the present invention, the initial figure is corrected into a corrected figure composed of at least two corrected rectangles; the arrangement direction of the at least two corrected rectangles is consistent with the direction of the initial figure.

[0034] In order to achieve the above-mentioned object of the invention, the present invention further provides a mask plate; the mask plate is prepared by using the mask plate pattern corrected by the above-mentioned mask plate pattern correction method.

[0035] In order to achieve the above-mentioned purpose of the invention, the present invention also provides a super surface structure; the super surface structure is formed by photolithography using the above-mentioned mask.

[0036] The beneficial effects of the present invention are as follows: in the method for correcting a mask plate pattern of the present invention, by correcting the initial pattern in the mask plate pattern into a corrected pattern composed of at least one corrected rectangle, two adjacent sides of the corrected rectangle extend along the X-axis and the Y-axis respectively, so that the corrected pattern in the corrected mask plate pattern can be compatible with the pattern import in the photolithography process, and a mask plate required for the production of the photolithography process can be prepared. The target supersurface structure, such as a polarization-dependent supersurface structure, is obtained by the photolithography process on a planar optical medium material using the mask plate, which is beneficial to the mass production of the polarization-dependent supersurface structure and the development of the supersurface structure in polarization imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Shown is a schematic diagram of an initial layout in a specific embodiment of the present invention;

[0038] FIG2( a ) is a schematic diagram of a structure in which the initial shape is a ring;

[0039] FIG2( b ) is a schematic diagram of the structure of a modified graph corresponding to the initial graph in FIG2( a );

[0040] FIG2( c ) is a cross-sectional view of a micro-nano unit corresponding to the modified pattern in FIG2( b );

[0041] FIG3( a ) is a schematic diagram of a structure in which the initial shape is a rectangle;

[0042] FIG3( b ) is a schematic diagram of the structure of the graph to be corrected of the initial graph in FIG3( a );

[0043] FIG3( c ) is a schematic diagram of the structure of a modified graph corresponding to the initial graph in FIG3( a );

[0044] FIG3( d ) is a cross-sectional view of a micro-nano unit corresponding to the modified pattern in FIG3( c );

[0045] FIG4( a ) is a schematic diagram of a structure in which the initial shape is V-shaped;

[0046] FIG4( b ) is a schematic diagram of the structure of a modified graph corresponding to the initial graph in FIG4( a );

[0047] FIG4( c ) is a cross-sectional view of a micro-nano unit corresponding to the modified pattern in FIG4( b );

[0048] FIG5( a ) is a schematic diagram of a structure in which the initial shape is an ellipse;

[0049] FIG5( b ) is a schematic diagram of the structure of a modified graph corresponding to the initial graph in FIG5( a );

[0050] FIG5( c ) is a cross-sectional view of a micro-nano unit corresponding to the modified pattern in FIG5( b );

[0051] Figure 6 The optical response diagram of the preset micro-nano unit corresponding to the initial pattern and the micro-nano unit corresponding to the corresponding modified pattern in Example 1 of the present invention;

[0052] Figure 7 The optical response diagram of the preset micro-nano unit corresponding to the initial pattern and the micro-nano unit corresponding to the corresponding modified pattern in Example 2 of the present invention;

[0053] Figure 8 The optical response diagram of the preset micro-nano unit corresponding to the initial pattern and the micro-nano unit corresponding to the corresponding modified pattern in Example 3 of the present invention;

[0054] Fig. 9 The optical response diagram of the preset micro-nano unit corresponding to the initial pattern and the micro-nano unit corresponding to the corresponding modified pattern in Example 4 of the present invention;

[0055] Fig.10 It is an optical response diagram of a preset micro-nano unit corresponding to the initial pattern in Embodiment 1 of the present invention, a micro-nano unit corresponding to the corresponding modified pattern, and a micro-nano unit formed after a mask lithography process with the modified pattern. DETAILED DESCRIPTION

[0056] The present invention will be described in detail below in conjunction with the various embodiments shown in the accompanying drawings. Figures 1 to 10 It is shown as a preferred embodiment of the present invention. However, it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformation or replacement of functions, methods, or structures made by ordinary technicians in the field according to these embodiments shall fall within the protection scope of the present invention.

[0057] Furthermore, it should be understood that although the terms first, second, etc. may be used in this document to describe various elements or structures, these described objects should not be limited by the above terms. The above terms are only used to distinguish these described objects from each other.

[0058] Combination Figure 1 As shown in Figure 5, the present invention provides a method for correcting a mask plate pattern. The corrected graphics in the corrected mask plate pattern are compatible with the pattern import in the photolithography process, and a mask plate required for the production of a photolithography process can be prepared. The mask plate is used to obtain a target metasurface structure, such as a polarization-dependent metasurface structure, on a planar optical medium material through a photolithography process, which is beneficial to the mass production of polarization-dependent metasurface structures and the development of metasurface structures in polarization imaging.

[0059] Specifically, the planar optical medium material includes but is not limited to silicon dioxide.

[0060] Specifically, a rectangular coordinate system with an X-axis and a Y-axis that are orthogonal to each other is defined.

[0061] Furthermore, the method for correcting the mask layout comprises the following steps:

[0062] Get the initial version Figure 1 , the initial version Figure 1 An initial graphic 11 having a one-to-one correspondence with a preset micro-nano unit in a target super-surface structure;

[0063] Correcting the initial figure 11 into a corrected figure consisting of at least one corrected rectangle 121, wherein two adjacent sides of the corrected rectangle 121 extend along the X axis and the Y axis respectively;

[0064] Get the vertex coordinates of the corrected shape.

[0065] It is known that when designing a super surface structure, the cross-sectional geometric parameters of the preset micro-nano units, such as shape, azimuth angle θ, etc., are designed according to the required optical response, and different preset micro-nano units together form the target super surface structure. Figure 1 .

[0066] In the present invention, by Figure 1 The initial figure 11 in the image is corrected into a corrected figure composed of at least one corrected rectangle 121, and the two adjacent sides of the corrected rectangle 121 extend along the X-axis and the Y-axis respectively, that is, the contour line of the corrected figure is composed of a horizontal line extending along the X-axis and a vertical line extending along the Y-axis, so that the contour lines of the corrected figure in the corrected mask plate are all composed of a horizontal line extending along the X-axis and a vertical line extending along the Y-axis, which is compatible with the layout import in the lithography process, and can prepare a mask plate required for the production of the lithography process. The target metasurface structure, such as a polarization-related metasurface structure, is obtained on a planar optical medium material through a lithography process using the mask plate, which is beneficial to the mass production of the polarization-related metasurface structure and the development of the metasurface structure in polarization imaging.

[0067] Specifically, the vertex of the correction figure refers to the intersection of a horizontal line and a vertical line forming the contour line of the correction figure.

[0068] It can be known that the correction figure in the corrected mask plate pattern is composed of at least one correction rectangle 121, and the correction rectangle 121 is formed by horizontal lines extending along the X-axis and vertical lines extending along the Y-axis, and the mask figure in the mask plate prepared by the corrected mask plate pattern corresponds one-to-one to the correction figure, and the micro-nano units in the super-surface structure formed by the mask plate lithography and the mask figure in the mask plate also correspond one-to-one, that is, the correction figure in the corrected mask plate pattern and the micro-nano units in the super-surface structure finally prepared correspond one-to-one, so the cross-section of the micro-nano unit in the super-surface structure finally obtained by using the mask plate for lithography is also formed by at least one rectangle 21, the corners in the rectangle 21 are rounded, and one of the two adjacent sides in each of the rectangles 21 extends along the X-axis, and the other extends along the Y-axis, that is, the contour line of the cross-section of the micro-nano unit is composed of a horizontal line extending along the X-axis and a vertical line extending along the Y-axis.

[0069] Furthermore, the ratio of the intersection area between the initial figure 11 and the corresponding corrected figure to the area of ​​the initial figure 11 is not less than 0.7, and the intersection area between the initial figure 11 and the corresponding corrected figure is increased as much as possible, so that the corrected figure can be kept in place relative to the initial figure 11 as much as possible, and the difference in optical response between the preset micro-nano unit corresponding to the initial figure 11 and the micro-nano unit corresponding to the corrected figure is reduced, so that the micro-nano unit corresponding to the corrected figure and the preset micro-nano unit corresponding to the initial figure 11 have similar optical responses, so that the finally prepared metasurface structure meets the required optical response.

[0070] Furthermore, the ratio of the area of ​​the initial pattern 11 to the area of ​​the corresponding modified pattern is 0.7 to 1.3. The area difference between the initial pattern 11 and the corresponding modified pattern is minimized as much as possible, and the difference in optical response between the preset micro-nano unit corresponding to the initial pattern 11 and the micro-nano unit corresponding to the modified pattern is reduced, so that the micro-nano unit corresponding to the modified pattern has a similar optical response to the preset micro-nano unit corresponding to the corresponding initial pattern, so that the finally prepared metasurface structure meets the required optical response.

[0071] Specifically, the absolute value of the phase difference between the phase of the preset micro-nano unit formed by the initial pattern 11 at a position where the transmittance is higher than 0.8 and the phase of the micro-nano unit formed by the modified pattern at a position where the transmittance is higher than 0.8 is not greater than 0.5 radians. Thus, the micro-nano unit corresponding to the modified pattern has a similar optical response to the preset micro-nano unit corresponding to the corresponding initial pattern 11, and the metasurface structure finally prepared meets the required optical response.

[0072] It should be noted that the above optical response refers to the transmittance and phase of the corresponding micro-nano unit in the direction of the x-axis and the transmittance and phase in the direction of the y-axis.

[0073] Furthermore, if Figure 2(a) to Figure 2(c) As shown, when the initial figure 11a is a circular ring, the above-mentioned "correcting the initial figure 11a to a corrected figure 12a composed of at least one corrected rectangle 121" specifically means: correcting the circular ring to a corrected figure 12a composed of a plurality of squares with the ring width of the circular ring as the side length, the distance between the center of the square and the inner ring of the circular ring is the same as the distance between the center of the square and the outer ring, and the two adjacent sides of the square extend along the X axis and the Y axis respectively. That is, when the initial figure 11a is a circular ring, the corrected rectangle 121 is a square with the same size and area.

[0074] Combination Figure 2(b) to 2(c) As shown, the obtained corrected figure 12a is formed by overlapping and arranging a number of squares of the same area, and the arrangement direction of the squares is consistent with the circular direction of the initial figure 11, that is, the preset extension direction of the squares is a ring line, and the corrected figure 12 after the combination of the squares is in a ring shape consistent with the direction of the initial figure 11. Correspondingly, the mask figure corresponding to the corrected figure 12a in the prepared mask plate and the cross-section of the micro-nano unit 2a corresponding to the corrected figure 12a in the finally formed supersurface structure are also formed by overlapping and arranging squares of the same area along the preset ring line direction, and the centers of the squares are located on the same circle.

[0075] Specifically, at least two right angles in each of the squares in the obtained correction figure 12a are located on the contour line of the correction figure 12a, and the inner ring and outer ring of the correction figure 12a are both composed of horizontal lines extending along the X axis and vertical lines extending along the Y axis. Correspondingly, at least two right angles in each of the squares in the mask figure corresponding to the correction figure 12a in the prepared mask are located on the contour line of the mask figure, and the inner ring and outer ring of the mask figure are both composed of horizontal lines extending along the X axis and vertical lines extending along the Y axis. Correspondingly, at least two right angles in each of the squares in the cross section of the micro-nano unit 2a corresponding to the mask figure in the final formed supersurface structure are located on the contour line of the cross section of the micro-nano unit 2a, and the inner ring and outer ring of the cross section of the micro-nano unit 2a are both composed of horizontal lines extending along the X axis and vertical lines extending along the Y axis.

[0076] It should be noted that the above-mentioned overlap means that two adjacent squares are in contact with each other. It may be that the two adjacent squares do not cross each other but only have adjacent sides that are in contact and overlap with each other, or that the two adjacent squares cross and overlap each other.

[0077] Furthermore, when the initial figure 11 is a non-circular ring, “correcting the initial figure 11 to a corrected figure consisting of at least one corrected rectangle 121” specifically includes the following steps:

[0078] dividing the initial figure 11 into at least one figure to be corrected;

[0079] Obtaining a correction rectangle 121 corresponding to the figure to be corrected;

[0080] The acquired correction rectangles 121 are combined to form the correction figure.

[0081] In a specific embodiment, "dividing the initial figure 11 into at least one figure to be corrected" specifically means: dividing the initial figure 11 into at least one figure to be corrected along the direction of the initial figure 11. Thus, the arrangement direction of the obtained correction rectangle 121 is consistent with the direction of the initial figure 11, that is, the direction of the final corrected figure is consistent with the direction of the corresponding initial figure 11, which can maximize the intersection area between the initial figure 11 and the corresponding corrected figure, and can keep the corrected figure in place relative to the initial figure 11 as much as possible; at the same time, it can reduce the difference in optical response between the preset micro-nano unit corresponding to the initial figure 11 and the micro-nano unit corresponding to the corresponding corrected figure, so that the micro-nano unit corresponding to the corrected figure and the preset micro-nano unit corresponding to the corresponding initial figure 11 have similar optical responses, so that the finally prepared metasurface structure meets the required optical response.

[0082] When the initial figure 11 is not segmented, that is, the initial figure 11 itself is a figure to be corrected, at this time, the corrected figure finally obtained is composed of only a corrected rectangle 121, that is, the corrected figure finally obtained is a square or rectangle with sides extending along the X-axis and the Y-axis. Specifically, if the initial figure 11 is a square, the initial figure 11 is not segmented at this time, and the initial figure 11 itself is the figure to be corrected. When the initial figure 11 is a non-square, such as a rectangle, an ellipse, a V-shape, etc., the initial figure 11 needs to be segmented, that is, the initial figure 11 is segmented into at least two figures to be corrected along the direction of the initial figure 11.

[0083] When the initial figure 11 includes a rectangle, the step of dividing the rectangle "dividing the initial figure 11 into at least one figure to be corrected along the direction of the initial figure 11" is specifically: dividing the rectangle into at least one figure to be corrected along the length direction of the rectangle.

[0084] The length of the long side of the rectangle is divided by the length of the short side to obtain a quotient a and a remainder b. In a specific embodiment, as shown in FIG3(a), the step of dividing the rectangle specifically includes the following steps:

[0085] When b=0, the rectangle is divided into a squares along the long side direction with the short side length as the side length, and the a squares are the figure to be corrected 111b;

[0086] When b≠0, the rectangle is divided into a squares and a rectangle along the long side direction with the short side length as the side length, and the a squares and the rectangle are the figure to be corrected 111b.

[0087] That is, when dividing a rectangle, the rectangle is divided along the length direction of the rectangle with the length of the short side of the rectangle as a unit. This can make the number of sides of the contour line of the final corrected pattern smaller, and the number of intersections of the horizontal and vertical lines in the corresponding contour line smaller. On the basis of making the corrected mask layout compatible with the layout import in the photolithography process, the data volume of the graphic file is further reduced, and the layout writing time in the mask preparation process is reduced, which is conducive to the mass production of polarization-dependent metasurface structures and the development of metasurface structures in polarization imaging.

[0088] It can be seen that when b=0, it indicates that the length of the long side of the rectangle is divisible by the length of the short side, so the rectangle can be divided into squares. When b≠0, it indicates that the length of the long side of the rectangle is not divisible by the length of the short side, so when the rectangle is divided along the long side with the short side as the side length of the square, a rectangle will eventually remain.

[0089] It can be seen that, as shown in FIG. 3( a ), when the initial figure 11 is a rectangle, the initial figure 11 can be directly segmented according to the above-mentioned rectangle segmentation steps to obtain a plurality of to-be-corrected figures corresponding to the initial figure 11 .

[0090] As shown in FIG4(a), when the initial figure 11 is a combination of rectangles and rectangles / squares with different orientations, the initial figure 11 can be regarded as a combination of rectangles with multiple orientations, and each rectangle with each orientation is divided according to the above-mentioned rectangle division steps to obtain a number of to-be-corrected figures 111c corresponding to the initial figure 11. As shown in FIG4(a), when the initial figure 11 is V-shaped, the initial figure 11 can be regarded as a combination of two rectangles with different orientations, and the two rectangles are divided according to the above-mentioned rectangle division steps to obtain a number of to-be-corrected figures 111c corresponding to the V-shaped initial figure 11.

[0091] When the initial figure 11 includes an ellipse, the step of dividing the ellipse into at least one figure to be corrected along the direction of the initial figure 11 is specifically: dividing the ellipse into at least one figure to be corrected along the long axis direction of the ellipse.

[0092] In a specific embodiment, as shown in FIG5(a), the initial figure 11 is an ellipse. Of course, this is not limiting, and in other embodiments, the initial figure 11 may also be a combination of an ellipse and other figures. In this case, the ellipse and other figures may be segmented to obtain a plurality of figures to be corrected corresponding to the initial figure 11.

[0093] In a specific embodiment, as shown in FIG. 5( a ), the ellipse segmentation step of “segmenting the ellipse into at least one figure to be corrected along the major axis direction of the ellipse” specifically includes the following steps:

[0094] Get the circumscribed rectangle of the ellipse, and divide the length of the long side of the circumscribed rectangle by the length of the short side to obtain the quotient c and the remainder d;

[0095] When d=0, the circumscribed rectangle is divided into c squares along the long side direction with the short side length of the circumscribed rectangle as the side length, and the c squares divide the initial figure 11 into c figures to be corrected 111d;

[0096] When d≠0, the circumscribed rectangle is divided into c squares and 1 rectangle along the long side direction with the short side length of the circumscribed rectangle as the side length. The c squares and 1 rectangle divide the initial figure 11 into (c+1) figures 111d to be corrected.

[0097] That is, when the ellipse is segmented, the ellipse is segmented along the length direction of the ellipse with the short side length of the circumscribed rectangle of the ellipse as a unit, that is, the ellipse is segmented along the extension direction of the long axis of the ellipse with the short axis length of the short axis of the ellipse as a unit. This can reduce the number of edges of the contour line of the final corrected pattern, and the number of intersections of the horizontal and vertical lines of the corresponding contour line is also small. On the basis of making the corrected mask layout compatible with the layout import in the photolithography process, the data volume of the graphic file is further reduced, and the layout writing time in the mask preparation process is reduced, which is conducive to the mass production of polarization-dependent metasurface structures and the development of metasurface structures in polarization imaging.

[0098] It can be seen that when d=0, it means that the length of the long side of the circumscribed rectangle is divisible by the length of the short side, so the circumscribed rectangle can be divided into squares. When d≠0, it means that the length of the long side of the circumscribed rectangle is not divisible by the length of the short side, so when the rectangle is divided along the long side direction with the short side as the side length of the square, a rectangle will eventually remain.

[0099] Furthermore, the center of the figure to be corrected overlaps with the center of the corresponding correction rectangle 121. Each correction rectangle 121 is kept in place as much as possible relative to the corresponding figure to be corrected, so that the final complete correction figure is kept in place as much as possible relative to the corresponding initial figure 11, and the difference in optical response between the preset micro-nano unit corresponding to the initial figure 11 and the micro-nano unit corresponding to the corresponding correction figure is reduced, so that the micro-nano unit corresponding to the correction figure and the preset micro-nano unit corresponding to the corresponding initial figure have similar optical responses, so that the finally prepared metasurface structure meets the required optical response.

[0100] Furthermore, the ratio of the area of ​​the figure to be corrected to the area of ​​the corresponding correction rectangle 121 is 0.7 to 1.3. By making the ratio of the area of ​​each figure to be corrected to the area of ​​the corresponding correction rectangle 121 0.7 to 1.3, the ratio of the area of ​​the final complete correction figure to the area of ​​the corresponding initial figure 11 satisfies 0.7 to 1.3, and the area difference between the initial figure 11 and the corresponding correction figure is minimized as much as possible, and the difference in optical response between the preset micro-nano unit corresponding to the initial figure 11 and the micro-nano unit corresponding to the corresponding correction figure is reduced, so that the micro-nano unit corresponding to the correction figure and the preset micro-nano unit corresponding to the initial figure 11 have similar optical responses, so that the finally prepared metasurface structure meets the required optical response.

[0101] It can be seen that, in combination with Figures 2 to 5, after the initial graphics 11b, 11c, 11d are divided into at least two graphics to be corrected along their direction, the obtained corrected graphics 12b, 12c, 12d corresponding to the initial graphics 11b, 11c, 11d are formed by combining at least two corrected rectangles 121, and the arrangement direction of the at least two corrected rectangles 121 is consistent with the direction of the initial graphics 11b, 11c, 11d. The cross-section of the corresponding micro-nano unit 2b, 2c, 2d corresponding to the corrected graphics 12b, 12c, 12d is formed by combining at least two rectangles 21 arranged overlapping along a preset extension direction, and the preset extension direction is the direction of the corresponding initial graphics 11.

[0102] Specifically, when the initial figure 11 is a figure extending in a single direction such as a rectangle or an ellipse, the preset extension direction of the cross section of the corresponding micro-nano unit is a straight line, and the centers of the rectangles constituting the cross section of the micro-nano unit are located on the same straight line; when the initial figure 11 is a figure extending in multiple directions such as a V-shape, the preset extension direction of the cross section of the corresponding micro-nano unit is a broken line, for example, when the initial figure 11c is V-shaped, the cross section of the corresponding micro-nano unit 2c is also V-shaped.

[0103] In a specific embodiment, in combination Figure 3(a) to 3(b) As shown, the step of obtaining the correction rectangle 121 "obtaining the correction rectangle 121 corresponding to the figure to be corrected" specifically includes the following steps:

[0104] Obtain a maximum inscribed rectangle R of the figure to be corrected, wherein the center of the maximum inscribed rectangle R overlaps with the center of the corresponding figure to be corrected, and two adjacent sides of the maximum inscribed rectangle R extend along the X-axis and the Y-axis respectively;

[0105] Obtaining a minimum circumscribed rectangle T of the figure to be corrected, wherein the center of the minimum circumscribed rectangle T overlaps with the center of the corresponding figure to be corrected, and two adjacent sides of the minimum circumscribed rectangle T extend along the X-axis and the Y-axis respectively;

[0106] An intermediate rectangle Q between the maximum inscribed rectangle R and the minimum circumscribed rectangle T is obtained. The intermediate rectangle Q is the correction rectangle 121 corresponding to the graphic to be corrected.

[0107] As shown in FIG3(b), when the figure to be corrected is a square, the corresponding correction rectangle 121 obtained by the above-mentioned correction rectangle 121 acquisition step is also a square; when the figure to be corrected is a rectangle, the corresponding correction rectangle 121 obtained by the above-mentioned correction rectangle 121 acquisition step is also a rectangle. Thus, when the initial figure 11 is a rectangle, the corresponding segmented figure to be corrected is a number of squares of the same area or a number of squares of the same area and a rectangle. At this time, the final correction figure corresponding to the initial figure 11 is also formed by overlapping a number of squares of the same area or by overlapping a number of squares of the same area and a rectangle. Correspondingly, the rectangle forming the cross section of the micro-nano unit in the final super surface structure is also a square of the same area, or the rectangle forming the cross section of the micro-nano unit includes a number of squares of the same area and a rectangle.

[0108] Combination Figure 3(c) , 4(b) 5(b), at least two right angles of each correction rectangle 121 in the obtained correction figure are located on the contour line of the correction figure, correspondingly, combined with Figure 3(d) , 4(c)As shown in FIG. 5( c ), at least two right angles in each rectangle 21 in the cross section of the micro-nano unit in the final supersurface structure are located on the contour line of the cross section of the micro-nano unit.

[0109] Furthermore, combined with Figure 2(c) , 3(d) As shown in Figures 4(c) and 5(c), the vertices in the contour line of the cross section of the micro-nano unit in the final supersurface structure are all chamfered corners, that is, the intersections of the horizontal lines and the vertical lines in the contour line of the cross section of the micro-nano unit in the final supersurface structure are all chamfered corners, that is, the corners formed by the overlapping intersections of adjacent rectangles 21 in the cross section constituting the micro-nano unit are chamfered corners, and the corners of each rectangle 21 are also chamfered corners.

[0110] Furthermore, the present invention also provides a mask prepared by using a mask pattern corrected by the above-mentioned mask pattern correction method, and a super surface structure formed by photolithography using the mask pattern.

[0111] The method for correcting the mask pattern is as described above, and the super-surface structure formed by photolithography using the mask is also as described above, and will not be repeated here.

[0112] The following will compare and illustrate the optical response of the preset micro-nano unit corresponding to the initial pattern 11 and the optical response of the micro-nano unit corresponding to the corresponding modified pattern with specific embodiments 1 to 4. The optical response is obtained by working at 940nm, using silicon dioxide as the substrate for the metasurface structure, and the micro-nano unit is an amorphous silicon column, wherein the height of the amorphous silicon column is 658nm, the period is 500nm, and no protective layer is set, and the incident light is uniformly x-polarized.

[0113] For the sake of distinction, the preset micro-nano unit corresponding to the initial pattern is called a nano-fin structure; the micro-nano unit corresponding to the corrected pattern is called a founder micro-structure.

[0114] Specifically, the initial pattern in Example 1 is a rectangle with a length of 300 nm, a width of 120 nm, and an azimuth angle θ varying from 0° to 180°.

[0115] According to the method for correcting the mask pattern of the present invention, a corrected pattern corresponding to the initial pattern is obtained, and the specific steps are as follows:

[0116] The initial pattern is divided into two squares with a side length of 120 nm and a rectangle with a length of 120 nm and a width of 60 nm along its length direction, that is, three patterns to be corrected are obtained;

[0117] Acquire three correction rectangles corresponding to the three figures to be corrected, and the specific method of acquiring the correction rectangle 121 is: respectively acquire the maximum inscribed rectangle and the minimum circumscribed rectangle of the figure to be corrected, wherein the centers of the maximum inscribed rectangle and the minimum circumscribed rectangle overlap with the center of the corresponding figure to be corrected, and the two adjacent sides of the maximum inscribed rectangle and the minimum circumscribed rectangle extend along the X-axis and the Y-axis respectively, and then acquire the middle rectangle between the maximum inscribed rectangle and the minimum circumscribed rectangle, and the middle rectangle is the correction rectangle corresponding to the figure to be corrected;

[0118] The three acquired correction rectangles are combined to form the correction figure.

[0119] It can be seen that the azimuth angle θ of the initial figure changes from 0° to 180°, and a correction figure corresponding to the azimuth angle is obtained accordingly.

[0120] like Figure 6 As shown, the optical response of the nanofin structure corresponding to the initial pattern and the founder microstructure corresponding to the modified pattern in Example 1 of the present invention is shown. It can be seen that the transmittance of the nanofin structure corresponding to the initial pattern and the founder microstructure corresponding to the modified pattern in Example 1 in the X direction and the Y direction is well matched, and the phase match is good where the transmittance is high, that is, the nanofin structure corresponding to the initial pattern and the founder microstructure corresponding to the modified pattern have similar optical responses.

[0121] The initial pattern in Example 2 is a rectangle with a length of 300 nm, a width of 150 nm, and an azimuth angle θ varying from 0° to 180°.

[0122] According to the method for correcting the mask pattern of the present invention, a corrected pattern corresponding to the initial pattern is obtained, and the specific steps are as follows:

[0123] The initial pattern is divided into two squares with a side length of 150 nm along its length direction, that is, two patterns to be corrected are obtained;

[0124] Acquire two correction rectangles corresponding to the two figures to be corrected, and the specific method of acquiring the correction rectangle 121 is: respectively acquire the maximum inscribed rectangle and the minimum circumscribed rectangle of the figure to be corrected, wherein the centers of the maximum inscribed rectangle and the minimum circumscribed rectangle overlap with the center of the corresponding figure to be corrected, and the two adjacent sides of the maximum inscribed rectangle and the minimum circumscribed rectangle extend along the X-axis and the Y-axis respectively, and then acquire the middle rectangle between the maximum inscribed rectangle and the minimum circumscribed rectangle, and the middle rectangle is the correction rectangle corresponding to the figure to be corrected;

[0125] The two obtained correction rectangles are combined to form the correction figure.

[0126] It can be seen that the azimuth angle θ of the initial figure changes from 0° to 180°, and a correction figure corresponding to the azimuth angle is obtained accordingly.

[0127] like Figure 7 As shown, the optical response of the nanofin structure corresponding to the initial pattern and the founder microstructure corresponding to the modified pattern in Example 2 of the present invention is shown. It can be seen that the transmittance of the nanofin structure corresponding to the initial pattern and the founder microstructure corresponding to the modified pattern in Example 2 in the X direction and the Y direction is well matched, and the phase match is good where the transmittance is high, that is, the nanofin structure corresponding to the initial pattern and the founder microstructure corresponding to the modified pattern have similar optical responses.

[0128] The initial pattern in Example 3 is a rectangle with a length of 300 nm, a width of 250 nm, and an azimuth angle θ varying from 0° to 180°.

[0129] According to the method for correcting the mask pattern of the present invention, a corrected pattern corresponding to the initial pattern is obtained, and the specific steps are as follows:

[0130] The initial pattern is divided into a square with a side length of 250 nm and a rectangle with a length of 250 nm and a width of 50 nm along its length direction, so as to obtain two patterns to be corrected;

[0131] Obtain two correction rectangles corresponding to the two figures to be corrected, and the specific method for obtaining the correction rectangles is: respectively obtain the maximum inscribed rectangle and the minimum circumscribed rectangle of the figure to be corrected, wherein the centers of the maximum inscribed rectangle and the minimum circumscribed rectangle overlap with the center of the corresponding figure to be corrected, and the two adjacent sides of the maximum inscribed rectangle and the minimum circumscribed rectangle extend along the X-axis and the Y-axis respectively, and then obtain the middle rectangle between the maximum inscribed rectangle and the minimum circumscribed rectangle, and the middle rectangle is the correction rectangle corresponding to the figure to be corrected;

[0132] The two obtained correction rectangles are combined to form the correction figure.

[0133] It can be seen that the azimuth angle θ of the initial figure changes from 0° to 180°, and a correction figure corresponding to the azimuth angle is obtained accordingly.

[0134] like Figure 8 As shown, the optical response of the nanofin structure corresponding to the initial pattern and the founder microstructure corresponding to the modified pattern in Example 3 of the present invention is shown. It can be seen that the transmittance of the nanofin structure corresponding to the initial pattern and the founder microstructure corresponding to the modified pattern in Example 3 in the X direction and the Y direction is well matched, and the phase match is good where the transmittance is high, that is, the nanofin structure corresponding to the initial pattern and the founder microstructure corresponding to the modified pattern have similar optical responses.

[0135] The initial pattern in Example 4 is a square with a side length of 300 nm, and the azimuth angle θ varies from 0° to 180°.

[0136] According to the method for correcting the mask pattern of the present invention, a corrected pattern corresponding to the initial pattern is obtained, and the specific steps are as follows:

[0137] The square is the figure to be corrected;

[0138] Obtaining a correction rectangle corresponding to the figure to be corrected. The specific method for obtaining the correction rectangle is: respectively obtaining the maximum inscribed rectangle and the minimum circumscribed rectangle of the figure to be corrected, wherein the centers of the maximum inscribed rectangle and the minimum circumscribed rectangle overlap with the center of the corresponding figure to be corrected, and the two adjacent sides of the maximum inscribed rectangle and the minimum circumscribed rectangle extend along the X-axis and the Y-axis respectively, and then obtaining the middle rectangle between the maximum inscribed rectangle and the minimum circumscribed rectangle, and the middle rectangle is the correction rectangle corresponding to the figure to be corrected;

[0139] The obtained correction rectangle forms the correction figure.

[0140] It can be seen that the azimuth angle θ of the initial figure changes from 0° to 180°, and a correction figure corresponding to the azimuth angle is obtained accordingly.

[0141] like Fig. 9 As shown, the optical response of the nanofin structure corresponding to the initial pattern and the founder microstructure corresponding to the modified pattern in Example 4 of the present invention is shown. It can be seen that the transmittance of the nanofin structure corresponding to the initial pattern and the founder microstructure corresponding to the modified pattern in Example 4 in the X direction is well matched, and the phase match is good where the transmittance is high, that is, the nanofin structure corresponding to the initial pattern and the founder microstructure corresponding to the modified pattern have similar optical responses.

[0142] It should be noted that when the initial pattern is a square, the transmittance of the corresponding micro-nano unit in the Y direction is low and the phase reference is not large.

[0143] Combination Fig.10 As shown, it is a comparison diagram of the optical responses of the nano-fin structure corresponding to the initial pattern 11 in Example 1, the square microstructure corresponding to the corresponding modified pattern, and the micro-nano unit with a rounded corner structure formed by the mask lithography process with the modified pattern. It can be seen that the corresponding nano-fin structure, square microstructure, and rounded corner structure have good transmittance and phase matching in the X direction, and the final metasurface structure can meet the requirements of optical response.

[0144] It should be noted that the micro-nano unit with rounded corners refers to the micro-nano unit with rounded corners at each vertex. Compared with the prior art, the correction method of the mask layout in the present invention corrects the initial figure 11 in the mask layout into a correction figure composed of at least one correction rectangle 121, and the two adjacent sides of the correction rectangle 121 extend along the X-axis and the Y-axis respectively, so that the correction figure in the corrected mask layout can be compatible with the layout import in the photolithography process, and the mask required for the production of the photolithography process can be prepared. The target super surface structure, such as the polarization-related super surface structure, is obtained by the photolithography process on the plane optical medium material using the mask, which is conducive to the mass production of the polarization-related super surface structure and the development of the super surface structure in polarization imaging.

[0145] It should be understood that although this specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation mode may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0146] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for correcting a mask layout, defining a rectangular coordinate system having orthogonal X-axis and Y-axis; Features: The method for correcting the mask layout comprises the following steps: Acquire an initial layout, wherein the initial layout has an initial pattern corresponding one-to-one to a preset micro-nano unit in a target metasurface structure; Correcting the initial figure into a corrected figure consisting of at least one corrected rectangle, wherein two adjacent sides of the corrected rectangle extend along the X axis and the Y axis respectively; Get the vertex coordinates of the corrected shape.

2. The method for correcting a mask pattern according to claim 1, Features: “Correcting the initial figure into a corrected figure consisting of at least one corrected rectangle” specifically includes the following steps: dividing the initial figure into at least one figure to be corrected; Get the correction rectangle corresponding to the figure to be corrected; The acquired correction rectangles are combined to form the correction figure.

3. The method for correcting a mask pattern according to claim 2, Features: "Obtaining a correction rectangle corresponding to the figure to be corrected" specifically includes the following steps: Obtaining a maximum inscribed rectangle of a figure to be corrected, wherein the center of the maximum inscribed rectangle overlaps with the center of the corresponding figure to be corrected, and two adjacent sides of the maximum inscribed rectangle extend along the X-axis and the Y-axis respectively; Obtaining a minimum bounding rectangle of the figure to be corrected, wherein the center of the minimum bounding rectangle overlaps with the center of the corresponding figure to be corrected, and two adjacent sides of the minimum bounding rectangle extend along the X-axis and the Y-axis respectively; The middle rectangle between the maximum inscribed rectangle and the minimum circumscribed rectangle is obtained, and the middle rectangle is the correction rectangle corresponding to the figure to be corrected.

4. The method for correcting a mask pattern according to claim 2, Features: The center of the graphic to be corrected overlaps with the center of the corresponding correction rectangle.

5. The method for correcting a mask pattern according to claim 2, Features: The ratio of the area of ​​the to-be-corrected figure to the area of ​​the corresponding correction rectangle is 0.7-1.

3.

6. The method for correcting a mask pattern according to claim 2, Features: “Dividing the initial graphic into at least one graphic to be corrected” specifically means: dividing the initial graphic into at least one graphic to be corrected along the direction of the initial graphic.

7. The method for correcting a mask pattern according to claim 6, Features: The initial figure includes a rectangle, and the quotient a and the remainder b are obtained by dividing the length of the long side of the rectangle by the length of the short side; the rectangle segmentation step "segmenting the initial figure into at least one figure to be corrected along the direction of the initial figure" specifically includes the following steps: When b=0, the rectangle is divided into a squares along the long side direction with the short side length as the side length, and the a squares are the figure to be corrected; When b≠0, the rectangle is divided into a squares and a rectangle along the long side direction with the short side length as the side length, and the a squares and the rectangle are the figures to be corrected.

8. The method for correcting a mask pattern according to claim 6, Features: The initial figure includes an ellipse; the ellipse segmentation step of "segmenting the initial figure into at least one figure to be corrected along the direction of the initial figure" specifically includes the following steps: Get the circumscribed rectangle of the ellipse, and divide the length of the long side of the circumscribed rectangle by the length of the short side to obtain the quotient c and the remainder d; When d=0, the circumscribed rectangle is divided into c squares along the long side direction with the short side length of the circumscribed rectangle as the side length, and the c squares divide the initial figure into c figures to be corrected; When d≠0, the circumscribed rectangle is divided into c squares and 1 rectangle along the long side direction with the short side length of the circumscribed rectangle as the side length. The c squares and 1 rectangle divide the ellipse into (c+1) figures to be corrected.

9. The method for correcting a mask pattern according to claim 2, Features: The initial figure is in the shape of a rectangle; or the initial figure is in the shape of a V; or the initial figure is in the shape of an ellipse; or the initial figure is in the shape of a ring.

10. The method for correcting a mask pattern according to claim 1, Features: The initial figure is a circular ring; "correcting the initial figure into a corrected figure composed of at least one corrected rectangle" specifically means: correcting the circular ring into a corrected figure composed of a plurality of squares with the ring width of the circular ring as the side length, the distance between the center of the square and the inner ring of the circular ring is the same as the distance between the center of the square and the outer ring, and the two adjacent sides of the square extend along the X-axis and the Y-axis respectively.

11. The method for correcting a mask pattern according to any one of claims 1 to 10, Features: The ratio of the area of ​​the intersection between the initial figure and the corresponding modified figure to the area of ​​the initial figure is not less than 0.

7.

12. The method for correcting a mask pattern according to any one of claims 1 to 10, Features: The ratio of the area of ​​the initial figure to the area of ​​the corresponding modified figure is 0.7 to 1.

3.

13. The method for correcting a mask pattern according to any one of claims 1 to 10, Features: The absolute value of the phase difference between the phase of the preset micro-nano unit formed by the initial pattern at a position where the transmittance is higher than 0.8 and the phase of the micro-nano unit formed by the correction pattern at a position where the transmittance is higher than 0.8 is not greater than 0.5 radians.

14. The method for correcting a mask pattern according to any one of claims 1 to 10, Features: The initial figure is corrected into a corrected figure composed of at least two corrected rectangles; the arrangement direction of the at least two corrected rectangles is consistent with the direction of the initial figure.

15. A mask; Features: The mask is prepared by using a mask pattern corrected by the mask pattern correction method described in any one of claims 1 to 14.

16. A super surface structure; Features: The super surface structure is formed by photolithography using the mask in claim 15.

Images