Imprint mask for nanoimprint lithography and its preparation method

Abstract

The present invention provides an imprint mask for nanoimprint lithography and a preparation method thereof. The entire layout is divided into multiple local regions, and the pattern duty cycle and pattern line width characteristics of the local regions are evaluated. At the same time, the feature size of the auxiliary pattern is corrected by the imprint process factor and the fluidity coefficient of the imprint material. Different from the underlying logic of lithography for correcting auxiliary patterns, the present invention takes into account the imprint process characteristics. Based on the filling rules of the layout characteristics and imprint characteristics, the duty cycle and layout of the entire layout are corrected by adding auxiliary patterns, thereby improving the filling uniformity of the imprint resist and the uniformity of the imprint bottom film.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor integrated circuit design and manufacturing, and particularly relates to an imprint mask for nanoimprint lithography and a preparation method thereof. Background Art

[0002] Nanoimprint is a low-cost manufacturing method for efficiently replicating micro-nano sized feature structures, with great potential to replace ultraviolet lithography technology for fabricating nano-scale patterns on wafers. This technology can be applied to the preparation of microfluidic chips, biochips, diffractive optical devices, augmented reality products, virtual reality products, etc. In recent years, the pattern resolution achieved based on this technology has approached 10 nm, and its application fields are also expected to expand to advanced semiconductor manufacturing.

[0003] The diffraction effect of ultraviolet lithography will cause distortion between the actually processed pattern and the original designed pattern. Usually, optical proximity correction technology (OPC) is used for correction. Analogous to the OPC technology of ultraviolet lithography, during pattern transfer in nanoimprint lithography, uneven pattern distribution will cause uneven bottom film thickness, further leading to problems such as uneven etching depth, large deviation between the etched pattern and the design, and poor yield.

[0004] Currently, when performing complex irregular patterning processes in nanoimprint lithography, there are problems of process defects caused by uneven bottom film, which will cause obvious defects in devices during actual use as a lithographic patterning process, thus affecting device performance. When the imprint resist is etched, the defects are further transferred and worsened.

[0005] In order to enable the imprinted and etched mask layer after imprinting of an irregular imprint layout to transfer the pattern 1:1 after etching, a uniform residual glue bottom film thickness is necessary.

[0006] It should be noted that the above introduction of the technical background is only for the convenience of clearly and completely explaining the technical solutions of the present application and facilitating the understanding of those skilled in the art. It cannot be considered that the above technical solutions are well-known to those skilled in the art just because these solutions are described in the background art part of the present application. Summary of the Invention

[0007] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide an imprint mask for nanoimprint lithography and a preparation method thereof, which are used to solve the problem of poor uniformity of the residual glue bottom film in the prior art.

[0008] To achieve the above and other related objectives, the present invention provides a method for preparing an imprint mask for nanoimprint lithography. The preparation method includes: 1) providing an imprint layout for producing an imprint template, the imprint layout including an original design pattern, and the original design pattern containing valid patterns; 2) extracting the valid pattern features of the original design pattern, defining the pattern width according to the pattern types of the valid pattern features, and dividing the original design pattern into multiple local regions according to the pattern types and pattern widths; 3) performing grid division on the local regions, calculating the average line width of the valid patterns in the local regions, and calculating the duty cycle of the valid patterns in the local regions according to the number of grids occupied by the valid patterns; 4) defining the auxiliary pattern feature sizes of the local regions according to the average line width of the valid patterns and the viscosity coefficient of the imprint material; 5) setting auxiliary patterns in the local regions according to the duty cycle and auxiliary pattern feature sizes of the local regions, where the shapes and sizes of the auxiliary patterns in the same local region are the same, and the auxiliary patterns are placed at the centers of each grid in the blank region of the local region to balance the uneven distribution of the valid patterns; 6) preparing an imprint mask according to the imprint layout after setting the auxiliary patterns.

[0009] Optionally, defining the pattern width according to the pattern types of the valid pattern features and dividing the original design pattern into multiple local regions includes: using the line width and shape features of the valid patterns as the basis for dividing the local regions. Among them, rectangles or combinations of rectangles with the same line width and the same shape are regarded as one type of pattern and then divided into the same local region; the rectangle is a pattern with a consistent width, including: 1) a rectangle with four right-angled vertices; 2) a parallelogram, where the average width between the long sides of the parallelogram is regarded as the rectangle width; 3) a trapezoid, where the height of the trapezoid or the average width between the two waists is regarded as the rectangle width; 4) an equal-width arc rectangle, where an arc with a bending radius ≤ 90° is regarded as an equal-width arc rectangle, and the shortest distance between the inner and outer sides of the equal-width arc rectangle is regarded as the rectangle width; 5) a ring, which is regarded as a combination of 4 equal-width arc rectangles; the combination of rectangles includes one of a discrete rectangle with a number of the same rectangles < 3, a grating-type rectangle combination with a number of the same rectangles ≥ 3, and an overlapping combination of multiple rectangles.

[0010] Optionally, dividing the original design pattern into multiple local regions according to the pattern types and pattern widths includes the step of: dividing patterns with similar line widths and the same pattern types into the same type of pattern to reduce pattern classification. The similar line widths mean that the line widths of the same pattern type are within a preset line width window range.

[0011] Optionally, dividing the original design pattern into a plurality of local regions according to the pattern type and pattern width includes the steps of: evaluating whether the pattern types of adjacent local regions are similar, and if they are similar, merging the adjacent local regions to reduce the number of auxiliary pattern designs.

[0012] Optionally, performing grid division on the local regions includes: dividing the original design pattern into N local regions, calculating the average line width values of the N local regions in the N regions respectively, and the average line width value of the Nth local region is w N ; meshing the N local regions respectively, and the Nth region is divided into n N meshes, where the size of the meshes is set to be greater than the average line width value w of the local region N .

[0013] Optionally, defining the auxiliary pattern feature size of each local region includes:

[0014] According to the imprinting process conditions, the viscosity coefficient of the imprinting material used is equivalent to the fluidity coefficient, and η0 is defined as the imprinting process factor: η0 = P0 × t0, where P0 is the pressure applied on the imprinting template and t0 is the duration of this pressure, then the fluidity coefficient of the imprinting material is α = η / η0, where η is the viscosity coefficient of the imprinting material used; defining the auxiliary pattern feature size of the local region as: a N = w N × α, where w N is the average line width value of the effective pattern in the Nth local region.

[0015] Optionally, the auxiliary pattern is a rectangle with both length and width of a N ; or the auxiliary pattern is a circle or an equilateral polygon with more than five sides having the same area as a rectangle with both length and width of a N .

[0016] Optionally, the duty cycle of the effective pattern is defined as: dividing a local region into n meshes n N , the number of meshes containing the effective pattern in the local region accounts for x of the total number of meshes in the local region, and the meshes without the effective pattern are blank meshes, then the local duty cycle of the Nth region is θ N = x N / n N , and inserting auxiliary patterns into the blank meshes of the local regions where the local duty cycle θ N < θ max , where θ max is the optimal local duty cycle of the local region.

[0017] Optionally, setting the auxiliary pattern includes: calculating the local duty cycle of N local regions in sequence, and repeating the insertion of the auxiliary pattern within the 1st to the Nth local regions.

[0018] Optionally, before preparing the imprint mask, it further includes the step of setting the thickness of the imprint material, where the thickness h of the imprint material is given by the formula: s1 / (s1 + s2) = 2h / (H + h), where s1 is the area of the concave pattern region on the imprint layout, s2 is the area of the convex pattern region on the imprint layout, H is the etching depth of the ideal groove pattern, and h is the thickness of the imprint material required before imprinting.

[0019] Optionally, before step 6), it further includes the step of performing a design rule check on the overall layout after setting the auxiliary pattern. If there are problems such as overlap or coverage of the auxiliary pattern over the valid pattern, return to step 3) - step 5) to repeat. If the layout check is correct, then perform the step of preparing the imprint mask.

[0020] The present invention also provides a method for manufacturing a semiconductor device, including the steps of: preparing an imprint mask based on the method for preparing an imprint mask for nanoimprint lithography described in any one of the above - mentioned solutions; manufacturing a semiconductor device based on the imprint mask.

[0021] Optionally, the semiconductor device includes one of a microfluidic chip, a biochip, a diffractive optical device, an LED display device, an augmented reality product, and a virtual reality product.

[0022] The present invention also provides an imprint mask, which is prepared based on the method for preparing an imprint mask for nanoimprint lithography described in any one of the above - mentioned solutions.

[0023] The present invention also provides an imprint device, which includes a processor and a memory. At least one instruction or program is stored in the memory, and the instruction or program is loaded and executed by the processor to implement the method for preparing an imprint mask for nanoimprint lithography described in any one of the above - mentioned solutions.

[0024] As described above, the imprint mask for nanoimprint lithography and its manufacturing method of the present invention have the following beneficial effects:

[0025] The present invention pre-corrects the nanoimprint design layout, intelligently divides the layout into grid points, divides the entire layout into multiple local regions, and evaluates the pattern duty cycle and pattern line width characteristics of the local regions. At the same time, the feature size of the auxiliary pattern is corrected by the imprint process factor and the fluidity coefficient of the imprint material. Different from the underlying logic of lithography for correcting auxiliary patterns, the present invention takes into account the imprint process characteristics, and based on the filling rules of the layout characteristics and imprint characteristics, corrects the duty cycle and layout of the entire layout by adding auxiliary patterns, thereby improving the filling uniformity of the imprint resist and improving the uniformity of the imprint bottom film.

[0026] Through optimization design, the present invention adds auxiliary patterns to the imprint layout to balance the imprint resist filling problem caused by the distribution of complex patterns, so that the concave parts of the imprint layout (imprint mold) can accommodate the imprint material and distribute it evenly. The obtained design has a high reduction degree and few process defects. The correction auxiliary pattern of this method can better adapt to the local line width, match the local material flow rate and filling efficiency, and optimize the local glue capacity, so that the imprint glue can flow and fill better, and then optimize the uniformity of the residual glue layer thickness of the overall layout and improve the process yield.

[0027] The improvement of the imprint mask process by the present invention can expand the types of devices prepared by it, improve the process yield, and break through the process limitations of the current imprint process for the preparation of non-regular graphic devices. Description of the Drawings

[0028] The included drawings are used to provide a further understanding of the embodiments of the present application. They form a part of the specification, are used to illustrate the implementation manners of the present application, and together with the text description, explain the principles of the present application. Obviously, the drawings in the following description are only some embodiments of the present application.

[0029] Figure 1 It shows a schematic flow chart of the preparation method of the imprint mask for nanoimprint lithography according to the embodiment of the present invention.

[0030] Figures 2 to 9 It shows several "rectangular" example schematic diagrams of the preparation method of the imprint mask for nanoimprint lithography according to the embodiment of the present invention.

[0031] Figure 10 It shows an enlarged structural schematic diagram of a local region in the preparation method of the imprint mask for nanoimprint lithography according to the embodiment of the present invention.

[0032] Figures 11 to 13 It shows a schematic diagram of different auxiliary pattern sizes corresponding to different patterns in the preparation method of the imprint mask for nanoimprint lithography according to the embodiment of the present invention.

[0033] Figure 14Schematic diagram of the method for setting the thickness of the imprint material in the preparation method of an imprint mask for nanoimprint lithography.

[0034] Figure 15 Schematic diagram of the layout of a silicon optical device after inserting traditional Dummy patterns and calibration auxiliary patterns.

[0035] Figures 16 to 17 Schematic diagram showing that different-sized auxiliary patterns are provided in different regions of the imprint layout for nanoimprint lithography in the embodiment of the present invention, where Figure 17 Shown as Figure 16 Schematic diagram of the enlarged structure of the middle region.

[0036] Figure 18 Optical microscope image of the imprint of the imprint mask.

[0037] Description of component labels

[0038] 1 Imprint layout

[0039] 11 Local area

[0040] 111 Grid occupied by effective pattern

[0041] 112 Empty grid

[0042] 113 Auxiliary pattern

[0043] 12 Effective pattern

[0044] 121 Trapezoid

[0045] 122 Long rectangular strip with equal width

[0046] 123 Circular arc with equal width

[0047] 21 Imprint layout

[0048] 22 Imprint material

[0049] 31 Dummy calibration auxiliary pattern

[0050] 32 First local area

[0051] 33 Second local area

[0052] 34 Third local area

[0053] 35 Fourth local area

[0054] 36 Fifth local area

[0055] 37 Sixth local area

[0056] 41 Poor uniformity of the residual bottom film

[0057] 42 Filling Defects Detailed Implementation Modes

[0058] The following describes the implementation modes of the present invention through specific examples. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0059] It should be emphasized that the term "comprising / including" when used herein refers to the presence of features, whole units, steps or components, but does not exclude the presence or addition of one or more other features, whole units, steps or components.

[0060] Features described and / or illustrated for one implementation mode can be used in the same or similar manner in one or more other implementation modes, combined with features in other implementation modes, or replace features in other implementation modes.

[0061] When detailing the embodiments of the present invention, for the sake of convenience of description, the cross-sectional views showing the device structure will be enlarged locally in a non-general proportion, and the schematic diagrams are only examples and should not limit the scope of protection of the present invention herein. In addition, in actual production, three-dimensional spatial dimensions including length, width and depth should be included.

[0062] For the sake of convenience of description, spatial relationship terms such as "beneath", "below", "lower than", "under", "above", "on" etc. may be used herein to describe the relationship between an element or feature shown in the drawings and other elements or features. It will be understood that these spatial relationship terms are intended to include other directions of the device in use or operation in addition to the directions depicted in the drawings. In addition, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or there can be one or more intervening layers.

[0063] In the context of the present application, the structure in which the first feature is "above" the second feature as described may include an embodiment in which the first and second features are formed in direct contact, and may also include an embodiment in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0064] It should be noted that the diagrams provided in this embodiment only illustrate the basic concept of the present invention schematically. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape and size of the components in actual implementation. The type, quantity and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0065] As Figures 1 to 18 shown, this embodiment provides a method for preparing an imprint mask for nanoimprint lithography. Figure 1 Shown is a flowchart of the preparation method of this embodiment. Please refer to Figure 1 the process shown. The preparation method includes:

[0066] As Figure 1 shown, first, step 1) is carried out to provide an imprint plate for producing an imprint template Figure 1 , and the imprint plate Figure 1 includes an original design pattern, and the original design pattern contains a valid pattern 12. The valid pattern 12 can be, for example, a pattern necessary for manufacturing a device or a chip.

[0067] As Figure 1 and Figures 2 to 9 、 Figure 10 shown, then step 2) is carried out to extract the features of the valid pattern 12 of the original design pattern, define the pattern width according to the pattern types of the valid pattern 12 features, and divide the original design pattern into multiple local regions 11 according to the pattern types and the pattern width.

[0068] In some embodiments, the valid patterns of the original design pattern usually have a very large number of pattern width values due to the complexity of the patterns. In this example, the pattern width can be defined according to the pattern types of the valid pattern 12 features, and the original design pattern can be divided into multiple local regions 11 according to the pattern types and the pattern width, including: using the line width and shape features of the valid pattern 12 as the basis for dividing the local regions 11. Among them, rectangles or combinations of rectangles with the same or similar line width and shape are regarded as one type of pattern and then divided into the same local region; the rectangle is a pattern composed of free curves (curves generated by various functions and algorithms). Approximate the free curves, and equivalent the patterns with the same or similar width to the following types of rectangles, and define the algorithm for the corresponding rectangle width. Some specific examples that can be regarded as "rectangles" are as follows:

[0069] 1) A rectangle with four right-angled vertices. For example, it can be a rectangle with a length less than 5 times the width, as Figure 2 shown, or a long rectangular strip with a length greater than 5 times the width, as Figure 3 shown. At this time, the width of the short side of the rectangle is used as the rectangle width.

[0070] 2) A trapezoid. Among them, the height of the trapezoid or the average width between the two waists is regarded as the rectangle width. For example, for a trapezoid with a bottom side greater than or equal to the height, as Figure 4 shown, at this time, the height of the trapezoid is used as the rectangle width, or for a trapezoid with a bottom side less than the height, as Figure 5 shown, at this time, the average width between the two waists of the trapezoid is used as the rectangle width.

[0071] 3) A parallelogram, where the average width between the long sides of the parallelogram is regarded as the width of the rectangle, as Figure 6 and Figure 7 shown.

[0072] 4) A constant-width arc rectangle, where an arc with a bending radius ≤ 90° is regarded as a constant-width arc rectangle, and the shortest distance between the inner and outer sides of the constant-width arc rectangle is regarded as the width of the rectangle, as Figure 8 and Figure 9 shown.

[0073] 5) A circular ring, which is regarded as a combination of 4 constant-width arc rectangles.

[0074] For example, when a region includes one or more "rectangles" of the above figures, if their rectangle widths are the same or similar, one or more of the above "rectangles" can be regarded as one figure and then divided into the same local region. If there are two "rectangles" with a large difference in rectangle width, they will be respectively assigned to two different local regions.

[0075] In one embodiment, the "rectangle" figure regarded as can be arranged in the same local region in the form of a rectangle combination. Usually, the rectangle combination includes: a discrete rectangle with a number of identical rectangles < 3, a raster rectangle combination with a number of identical rectangles ≥ 3, and an overlapping combination of multiple rectangles, etc.

[0076] In one embodiment, the step of dividing the original design figure into multiple local regions 11 according to the figure type and figure width includes: dividing figures with similar line widths and the same figure type into the same figure type to reduce figure classification. The similar line widths mean that the line widths of figures of the same figure type are within a pre-set line width window range, as Figure 10 shown, Figure 10 the effective Figure 12 figures include a) a circular arc 123 with a constant width, and two circular arcs are combined to form a semi-circle, regarded as the first rectangle, b) a long strip rectangle 122 with a constant width, and two long strip rectangles arranged alternately on the upper and lower sides are combined into the second rectangle, c) a trapezoid 121, and two trapezoids arranged alternately on the upper and lower sides are combined into the third rectangle. Then, for the above three adjacent rectangles in sequence, it is judged that their line widths are relatively close, so the regions of the above three rectangles can be combined as the same local region.

[0077] In one embodiment, dividing the original design pattern into a plurality of local regions 11 according to the pattern type and pattern width includes the steps of: evaluating whether the pattern types of adjacent local regions 11 are similar, and if they are similar, merging the adjacent local regions 11 to reduce the number of auxiliary pattern designs. It should be noted that the basis for whether the pattern types are similar can be: 1) patterns with the same or similar width and the same pattern type; 2) patterns with the same or similar width and different pattern types, etc.

[0078] As Figure 1 and Figure 10 shown, then perform step 3), divide the local region 11 into grids, calculate the average line width of the effective patterns 12 in the local region 11, and calculate the duty cycle of the effective patterns 12 in the local region 11 according to the number of grids 111 occupied by the effective patterns 12.

[0079] In one embodiment, the duty cycle of the effective pattern 12 is defined as: dividing a local region 11 into n grids n N , the number of grids 111 containing the effective pattern 12 in the local region 11 is x, the grids without the effective pattern 12 are blank grids 112, then the local duty cycle of the Nth region is θ N =x N / n N , where, subsequently, in the blank grids 112 of the local region 11 where the local duty cycle θ N <θ max , insert the auxiliary pattern 113, where θ max is the optimal local duty cycle of the local region 11. That is, when the local duty cycle is less than the optimal local duty cycle, the auxiliary pattern 113 can be inserted into the blank grids 112 of the local region, and finally the ratio between the protruding patterns and the concave patterns in the local region is equal to or close to the optimal local duty cycle. In one embodiment, the optimal local duty cycle can be between 20% and 80%. When the bottom film thickness is 0, the ideal optimal local duty cycle is 50%. In one embodiment, dividing the local region 11 into grids includes: dividing the original design pattern into N local regions 11, calculating the average line width values of the N local regions 11 in the N regions respectively, and the average line width value of the Nth local region 11 is w N ; meshing the N local regions 11 respectively, the Nth region is divided into n N grids, where the size of the grids is set to be greater than the average line width value w N of the local region 11.

[0080] As Figure 1 , Figure 10 and Figures 11 to 13As shown, then perform step 4). Define the feature size of the auxiliary pattern 113 in each local area 11 according to the average line width of the effective pattern 12 and the viscosity coefficient of the imprinting material.

[0081] In one embodiment, defining the feature size of the auxiliary pattern 113 in each local area 11 includes:

[0082] According to the imprinting process conditions, the viscosity coefficient of the used imprinting material is equivalent to the fluidity coefficient. Define η0 as the imprinting process factor: η0 = P0 × t0, where P0 is the pressure applied to the imprinting template and t0 is the duration of the action of this pressure. Then the fluidity coefficient of the imprinting material is α = η / η0, where η is the viscosity coefficient of the used imprinting material. Define the feature size of the auxiliary pattern 113 in the local area 11 as: a N = w N × α, where w N is the average line width value of the effective pattern 12 in the Nth local area 11. In one embodiment, as Figure 11 shown, for a rectangle with a uniform line width of wa, assuming the fluidity coefficient α of the imprinting material is 1, the feature size of each auxiliary pattern 113 is also wa; as Figure 12 shown, for a combination of rectangles with average line widths of wa and wb respectively, the feature size wc of each auxiliary pattern 113 is related to wa and wb. Here, the feature size wc of the auxiliary pattern 113 is the average of the two rectangles according to the proportion, and wc is between wa and wb; as Figure 13 shown, for a combination of rectangles with different line widths (wa, wd, and we), the feature size wf of each auxiliary pattern 113 is related to wa, wd, and we. Here, wf is the average of multiple rectangles according to the proportion. Since the area occupied by we is larger and its influence on the average is greater, the feature size wf of the auxiliary pattern 113 is greater than wa and wd and less than we.

[0083] In one embodiment, the auxiliary pattern 113 is a rectangle with both length and width of a N . Of course, in other embodiments, the auxiliary pattern 113 can also be a circle or an equilateral polygon with more than five sides having the same area as a rectangle with both length and width of a N .

[0084] As Figure 1 , Figure 10 and Figures 11 to 13 shown, then perform step 5). Set the auxiliary pattern 113 in the local area 11 according to the duty cycle of the local area 11 and the feature size of the auxiliary pattern 113. The shapes and sizes of the auxiliary patterns 113 in the same local area 11 are the same. The auxiliary pattern 113 is placed at the center of each grid in the blank area of the local area to balance the uneven distribution of the effective pattern 12. Among them, the effective pattern 12 is on the imprinting plateFigure 1 (The imprinting mold) is set as a groove (corresponding to a protrusion on the imprinting colloid), and the auxiliary pattern 113 is on the imprinting plate Figure 1 (The imprinting mold) is set as a groove (corresponding to a protrusion on the imprinting colloid). Specifically, the purpose of the auxiliary pattern is to accommodate the excess imprinting colloid. Suppose when the line width of a finite pattern is very small, there is residual colloid remaining after the imprinting colloid fills the pattern, and when there are differences in the line widths of each region, it will cause uneven residual colloid thickness. The present invention sets the auxiliary pattern of the groove to accommodate the excess imprinting colloid. By controlling the line width of the auxiliary pattern to be the same as or close to the value obtained by multiplying the average line width value of the effective pattern by the fluidity coefficient, the auxiliary pattern can more effectively and evenly accommodate the excess imprinting colloid. At the same time, by setting the auxiliary pattern to jointly form a groove pattern with the effective pattern, the final duty cycle of the groove pattern and the protrusion pattern in the local area is finally adjusted to the optimal duty cycle, so that the thickness of the residual bottom film after imprinting is 0 or close to 0.

[0085] In one embodiment, setting the auxiliary pattern 113 includes: sequentially calculating the local duty cycles of N local regions 11, and repeating the insertion of the auxiliary pattern 113 in the 1st to the Nth local regions 11.

[0086] In one embodiment, it further includes the step of: performing a design rule check on the overall layout after setting the auxiliary pattern 113. If there is a problem that the auxiliary pattern 113 overlaps or covers the effective pattern 12, then return to re-perform steps 3) to 5). If the layout check is correct, then perform the step of preparing the imprinting mask plate.

[0087] In one embodiment, before preparing the imprinting mask plate, it further includes the step of setting the thickness of the imprinting material 22, where the thickness h of the imprinting material is given by the following formula: s1 / (s1 + s2)=h / H, where s1 is the area of the concave pattern region on the imprinting layout 21, s2 is the area of the convex pattern region on the imprinting layout 21, H is the ideal etching depth of the groove pattern, and h is the thickness of the imprinting material 22 required before imprinting.

[0088] Specifically, as Figure 14 shown, s1 is the area of the concave pattern region on the imprinting layout 21, s2 is the area of the convex pattern region on the imprinting layout 21, H is the ideal etching depth of the groove pattern, h is the thickness of the glue layer required before imprinting, and h2’ is the thickness of the residual glue layer after imprinting. Then there is:

[0089] The ideal pattern etching depth is Equation 1: H = h1 + h2;

[0090] The glue coating thickness before imprinting is Equation 2: h = h2 + h2’;

[0091] The layout duty ratio of the fabricated imprint layout is Equation 3: s1 / (s1 + s2);

[0092] Based on the principle of constant volume of the imprinted glue layer, Equation 4 can be obtained: s2h2 = s1h1;

[0093] Substituting Equation 1 into Equation 4, Equation 5 can be obtained: s2h2 = s1(H - h2);

[0094] By transposing Equation 5, Equation 6 can be obtained: (s1 + s2)h2 = s1H;

[0095] Substituting Equation 2 into Equation 6, Equation 7 can be obtained: (s1 + s2)(h - h2’) = s1H;

[0096] In an ideal situation, there is no residual bottom film in the groove, that is, h2’ = 0, and the above formula can be simplified to s1 / (s1 + s2) = h / H. According to the above formula, the thickness of the imprinted glue layer can be calculated based on the layout duty ratio of the fabricated imprint layout. At the same time, it can be seen that the layout duty ratio is a factor affecting the filling of the imprinted colloid. In an ideal situation, when the fluidity of the colloid is extremely good, when s1 = s2 and h = H / 2, the colloid can be completely filled without any residual bottom film.

[0097] Finally, perform step 6), and prepare an imprint mask template based on the imprint plate Figure 1 , after setting the auxiliary pattern 113.

[0098] Figures 11 to 13 Shows the auxiliary patterns of multiple local regions. From Figures 11 to 13 it can be seen that the auxiliary patterns matched by different effective pattern combinations are of different sizes. Since when the imprint lithography process is extended to more application scenarios, the distribution of the imprint layout patterns may be uneven and the pattern line widths may also be non-uniform. The auxiliary patterns of the present invention can better adapt to the line widths of local regions, match the glue flow rate and filling efficiency of local regions, and optimize the glue capacity of local regions, so that the imprint glue can flow and fill better. Therefore, the thickness uniformity of the residual glue layer of the overall imprint layout can be optimized, and the process yield can be improved.

[0099] Appendix Figure 15 Shows the layout of a silicon photonics device, which includes the effective pattern 12, the layout after inserting the traditional Dummy pattern and the correction auxiliary pattern 31. The traditional Dummy pattern is defined according to the layout duty ratio. The Dummy pattern is a uniform pattern array, as Figure 15 shown; as Figure 16 and Figure 17 shown, where Figure 17 is shown as Figure 16Schematic diagram of the enlarged structure of the central region. The auxiliary patterns defined in the present invention are non-uniform among different regions in the entire layout. The sizes of the auxiliary patterns are defined based on the effective pattern features of the local regions, and then the size values are corrected according to the characteristics of the imprint glue used. It can be divided into a first local region 32, a second local region 33, a third local region 34, a fourth local region 35, a fifth local region 36, and a sixth local region 37. Among them, according to the types and line width distributions of the effective patterns, the first local region 32 and the fourth local region 35 can be combined, the second local region and the fifth local region 36 can be combined, and the third local region 34 and the sixth local region 37 can also be combined, finally forming 3 local regions with different auxiliary pattern sizes. Compared with the uniform Dummy patterns in the traditional layout, the auxiliary patterns of the present invention can better accommodate the filling of the imprint glue and improve the process yield.

[0100] Appendix Figure 18 Shows an optical microscope image of the imprint mask. Comparing the area with auxiliary patterns and the area without auxiliary patterns, problems such as significant residual bottom film uniformity difference 41 and filling defects 42 appear near the area without auxiliary patterns. During imaging, it is mainly manifested as chromatic aberration, indicating that inserting the auxiliary patterns of the present invention can optimize the problem of imprint bottom film uniformity.

[0101] This embodiment also provides a method for manufacturing a semiconductor device, including the steps of: preparing an imprint mask based on the method for preparing an imprint mask for nanoimprint lithography according to any one of the above-mentioned solutions; manufacturing a semiconductor device based on the imprint mask.

[0102] In some embodiments, the semiconductor device includes one of a microfluidic chip, a biochip, a diffractive optical device, an LED display device, an augmented reality product, and a virtual reality product. Of course, the semiconductor device is not limited to the examples listed above, and the semiconductor device can also be extended to power semiconductor devices, storage devices, logic devices, etc.

[0103] This embodiment also provides an imprint mask, which is prepared based on the method for preparing an imprint mask for nanoimprint lithography according to any one of the above-mentioned solutions.

[0104] This embodiment also provides an imprint device, which includes a processor and a memory. At least one instruction or program is stored in the memory, and the instruction or program is loaded and executed by the processor to implement the method for preparing an imprint mask for nanoimprint lithography according to any one of the above-mentioned solutions.

[0105] The processor can be a central processing unit (CPU), a network processor (NP), or a combination of a central processing unit (CPU) and a network processor (NP). The processor may further include a hardware chip. The above-mentioned hardware chip can be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The above-mentioned programmable logic device (PLD) can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof.

[0106] The memory is connected to the processor through a bus or other means. At least one instruction, at least one program, a code set, or an instruction set is stored in the memory. The above-mentioned at least one instruction, at least one program, code set, or instruction set is loaded and executed by the processor to implement the method for preparing an imprint mask plate for nanoimprint lithography as described in the embodiments of the present application. The memory can be a volatile memory, a non-volatile memory, or a combination thereof. The volatile memory can be a random access memory (RAM), such as a static random access memory (SRAM), a dynamic random access memory (DRAM), etc. The non-volatile memory can be a read-only memory (ROM), such as a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), etc. The non-volatile memory can also be a flash memory, a magnetic memory, such as a magnetic tape, a floppy disk, a hard disk, an optical disk, etc.

[0107] As described above, the imprint mask plate for nanoimprint lithography and the method for preparing the same according to the present invention have the following beneficial effects:

[0108] The present invention pre-corrects the nanoimprint design layout, intelligently divides the layout into grid points, divides the entire layout into multiple local areas, and evaluates the pattern duty cycle and pattern line width characteristics of the local areas. At the same time, the feature size of the auxiliary pattern is corrected with the imprint process factor and the imprint material fluidity coefficient. Different from the underlying logic of lithography for correcting the auxiliary pattern, the present invention takes into account the imprint process characteristics, and based on the filling rules of the layout characteristics and imprint characteristics, corrects the duty cycle and layout of the entire layout by adding auxiliary patterns, thereby improving the filling uniformity of the imprint resist and improving the uniformity of the imprint bottom film.

[0109] Through optimized design, the present invention adds auxiliary patterns to the imprint layout to balance the imprint resist filling problem caused by the distribution of complex patterns, enabling the concave areas of the imprint layout (imprint mold) to accommodate the imprint material and distribute it evenly. The imprinted design has a high degree of design restoration and few process defects. The calibration auxiliary patterns of this method can better adapt to the line width of the local area, match the local material flow rate and filling efficiency, and optimize the local amount of resist accommodated, enabling the imprint resist to flow and fill better, thereby optimizing the uniformity of the residual resist layer thickness of the overall layout and improving the process yield.

[0110] The improvement of the imprint mask process by the present invention can expand the types of devices prepared by it, improve the process yield, and break through the process limitations of the current imprint process for the preparation of non-regular graphic devices.

[0111] Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0112] The above embodiments are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing an imprint mask for nanoimprint lithography, characterized in that: The preparation method comprises: 1) providing an imprinting plate for producing an imprinting template, wherein the imprinting plate comprises an original design graphic, and the original design graphic comprises an effective graphic; 2) extracting effective graphic features of the original design graphic, defining a graphic width according to the graphic type of the effective graphic features, and dividing the original design graphic into a plurality of local areas according to the graphic type and the graphic width; 3) dividing the local area into grids, calculating the average line width of the effective graphics in the local area, and calculating the duty cycle of the effective graphics in the local area according to the number of grids occupied by the effective graphics; 4) defining the feature size of the auxiliary pattern in each local area according to the average line width of the effective pattern and the viscosity coefficient of the imprint material; 5) Arranging auxiliary patterns in the local area according to the duty ratio of the local area and the characteristic size of the auxiliary patterns, the auxiliary patterns in the same local area have the same shape and size, and the auxiliary patterns are placed at the center of each grid in the blank area of ​​the local area; 6) preparing an imprint mask according to the imprint pattern after setting the auxiliary pattern; The duty cycle of the effective pattern is defined as: a local area is divided into n grids n N , the number of grids in the local area occupied by the grids containing valid graphics is x, and the grids without valid graphics are blank grids, then the local duty cycle of the Nth area is θ N =x N / n N ; The auxiliary graphic feature dimensions that define each local area include: According to the imprint process conditions, the viscosity coefficient of the imprint material used is equivalent to the fluidity coefficient, and η0 is defined as the imprint process factor: η0=P0×t0, where P0 is the pressure applied to the imprint template, and t0 is the duration of the pressure. The fluidity coefficient of the imprint material is α=η / η0, where η is the viscosity coefficient of the imprint material used; The auxiliary graphic feature size of the local area is defined as: a N =w N ×α, where w N is the average line width of the valid graphics in the Nth local area.

2. The method for preparing an imprint mask for nanoimprint lithography according to claim 1, characterized in that: Defining a graphic width according to the graphic type of the effective graphic feature, and dividing the original design graphic into a plurality of local areas according to the graphic type and the graphic width, including: using the line width and shape characteristics of the effective graphic as the basis for dividing the local areas, wherein rectangles or combinations of rectangles with equal line width and the same shape are regarded as a graphic and then divided into the same local area; The rectangle is a figure with uniform width, including: 1) a rectangle with four right angles; 2) a parallelogram, wherein the average width between the long sides of the parallelogram is regarded as the width of the rectangle; 3) a trapezoid, wherein the height of the trapezoid or the average width between the two sides is regarded as the width of the rectangle; 4) an arc rectangle with equal width, wherein an arc with a bending radius of ≤90° is regarded as an arc rectangle with equal width, and the shortest distance between the inner and outer sides of the arc rectangle with equal width is regarded as the width of the rectangle; 5) a ring, which is regarded as a combination of 4 arc rectangles with equal width; The rectangle combination includes one of: a discrete rectangle with the number of identical rectangles less than 3, a grating rectangle combination with the number of identical rectangles greater than or equal to 3, and an overlapping combination of multiple rectangles.

3. The method for preparing an imprint mask for nanoimprint lithography according to claim 1, characterized in that: Dividing the original design graphic into multiple local areas according to the graphic type and graphic width includes the steps of: dividing graphics with similar line width and the same graphic type into the same graphic type to reduce graphic classification, wherein the similar line width means that the line width of the same graphic type is within a preset line width window range.

4. The method for preparing an imprint mask for nanoimprint lithography according to claim 3, characterized in that: Dividing the original design graphic into a plurality of local areas according to the graphic type and the graphic width includes the steps of: evaluating whether the graphic types of adjacent local areas are similar, and if similar, merging the adjacent local areas to reduce the number of auxiliary graphic designs.

5. The method for preparing an imprint mask for nanoimprint lithography according to claim 1, characterized in that: Meshing the local area includes: The original design pattern is divided into N local areas, and the average line width of the N local areas is calculated in the N areas. The average line width of the Nth local area is w N ; The N local regions are meshed separately, and the Nth region is divided into n N A grid, wherein the size of the grid is set to be larger than the average line width value w of the local area N .

6. The method for preparing an imprint mask for nanoimprint lithography according to claim 1, characterized in that: The auxiliary figure has a length and a width. N or the auxiliary figure is a rectangle with a length and width of N The area of ​​a rectangle is equal to that of a circle or an equilateral polygon with more than five sides.

7. The method for preparing an imprint mask for nanoimprint lithography according to claim 1, characterized in that: In the local duty cycle θ N <θ max Insert the auxiliary graphics into the blank grid of the local area, where θ max is the optimal local duty cycle for this local area.

8. The method for preparing an imprint mask for nanoimprint lithography according to claim 7, characterized in that: Setting the auxiliary pattern includes: calculating the local duty ratios of N local areas in sequence, and repeatedly inserting the auxiliary pattern in the first to Nth local areas.

9. The method for preparing an imprint mask for nanoimprint lithography according to claim 1, characterized in that: Before preparing the imprint mask, the step of setting the thickness of the imprint material is also included, wherein the thickness h of the imprint material is given by the following formula: s1 / (s1+s2)=h / H, wherein s1 is the area of ​​the concave pattern area on the imprint plate, s2 is the area of ​​the convex pattern area on the imprint plate, H is the ideal groove pattern etching depth, and h is the thickness of the imprint material required before imprinting.

10. The method for preparing an imprint mask for nanoimprint lithography according to claim 1, characterized in that: Before step 6), the process also includes the following steps: performing a design rule check on the overall layout after setting the auxiliary graphics. If there is a problem of the auxiliary graphics overlapping or covering the effective graphics, returning to step 3) to step 5) again. If the layout check is correct, the step of preparing the imprint mask is performed.

11. A method for preparing a semiconductor device, characterized in that: Includes steps: Preparing an imprint mask according to the method for preparing an imprint mask for nanoimprint lithography according to any one of claims 1 to 10; A semiconductor device is manufactured based on the imprint mask.

12. The method for preparing a semiconductor device according to claim 11, characterized in that: The semiconductor device includes one of a microfluidic chip, a biochip, a diffractive optical device, an LED display device, an augmented reality product and a virtual reality product.

13. An imprint mask, characterized in that: The imprint mask is prepared based on the method for preparing an imprint mask for nanoimprint lithography according to any one of claims 1 to 11.

14. An imprinting device, characterized in that: The imprinting device comprises a processor and a memory, wherein the memory stores at least one instruction or program, and the instruction or program is loaded and executed by the processor to implement the method for preparing an imprint mask for nanoimprint lithography according to any one of claims 1 to 10.

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