Imprint mask for nanoimprint lithography and preparation method thereof

Abstract

The invention provides an imprint mask for nanoimprint lithography and a preparation method thereof, the whole layout is divided into a plurality of local areas, the pattern duty ratio and pattern line width characteristics of the local areas are evaluated, and meanwhile, the characteristic size of an auxiliary pattern is corrected by an imprint process factor and an imprint material fluidity coefficient. Different from the underlying logic of a photoetching correction auxiliary pattern, the method considers the characteristics of the imprinting process, and corrects the duty ratio and layout of the whole layout by adding the auxiliary pattern based on the layout characteristics and the filling rule of the imprinting characteristics, thereby improving the filling uniformity of the imprinting resist and improving the uniformity of the imprinting bottom film.

Description

Technical Field

[0001] The invention belongs to the field of semiconductor integrated circuit design and manufacture, and in particular relates to an imprint mask plate for nano-imprint lithography and a preparation method thereof. Background Art

[0002] Nanoimprinting is a low-cost manufacturing method for efficiently replicating micro- and nano-sized feature structures. It has great potential to replace UV lithography and realize nanoscale pattern preparation on wafers. This technology can be used to prepare microfluidic chips, biochips, diffractive optical devices, augmented reality products, virtual reality products, etc. In recent years, the image resolution achieved by this technology has approached 10nm, and its application field is also expected to expand to advanced semiconductor manufacturing.

[0003] The diffraction effect of UV lithography can cause distortion between the actual processed pattern and the original design pattern, which is usually corrected by optical proximity correction (OPC). Similar to the OPC technology of UV lithography, when transferring patterns in nanoimprint lithography, uneven pattern distribution can cause uneven thickness of the base film, which further causes problems such as uneven etching depth, large deviation between the etched pattern and the design, and poor yield.

[0004] At present, the problem of process defects caused by uneven substrate film when performing complex irregular patterning in nanoimprint lithography will cause obvious defects in the device when it is actually used as a lithography patterning process, thereby affecting the device performance. When the imprint resist is etched, the defects are further transferred and worsened.

[0005] In order to ensure that the embossing mask layer after the irregular embossing pattern can transfer the pattern 1:1 after etching, a uniform thickness of the residual adhesive bottom film is necessary.

[0006] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the present application and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because they are described in the background technology section of the present application. Summary of the invention

[0007] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide an imprint mask for nanoimprint lithography and a preparation method thereof, so as to solve the problem of poor uniformity of the residual adhesive base film in the prior art.

[0008] To achieve the above-mentioned purpose and other related purposes, the present invention provides a method for preparing an imprint mask for nanoimprint lithography, the preparation method comprising: 1) providing an imprint plate for producing an imprint template, the imprint plate comprising an original design graphic, the original design graphic comprising 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 feature, and dividing the original design graphic into a plurality of local areas according to the graphic type and the graphic width; 3) gridding the local area, and calculating the average line width of the effective graphic in the local area, and calculating the duty cycle of the effective graphic in the local area according to the number of grids occupied by the effective graphic; 4) defining the auxiliary graphic feature size of each local area according to the average line width of the effective graphic and the viscosity coefficient of the imprint material; 5) setting auxiliary graphics in the local area according to the duty cycle of the local area and the auxiliary graphic feature size, the auxiliary graphics in the same local area have the same shape and size, and the auxiliary graphics are placed at the center of each grid of the blank area of ​​the local area to balance the uneven distribution of the effective graphics; 6) preparing an imprint mask according to the imprint plate after setting the auxiliary graphics.

[0009] Optionally, the graphic width is defined according to the graphic type of the effective graphic feature, and the original design graphic is divided into multiple 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 local area division, 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 rectangles are graphics with consistent width, including: 1) rectangles with four right angles; 2) parallelograms, wherein the average width between the long sides of the parallelogram is regarded as the rectangle width; 3) trapezoids, wherein the height of the trapezoid or the average width between the two sides is regarded as the rectangle width; 4) arc rectangles of equal width, wherein an arc with a bending radius of ≤90° is regarded as an arc rectangle of equal width, and the shortest distance between the inner and outer sides of the arc rectangle of equal width is regarded as the rectangle width; 5) rings, which are regarded as a combination of 4 arc rectangles of equal width; the rectangle combination includes: a discrete rectangle with the number of identical rectangles <3, a grating rectangle combination with the number of identical rectangles ≥3, and an overlapping combination of multiple rectangles.

[0010] Optionally, dividing the original design graphic into multiple local areas based on the graphic type and graphic width includes the steps of: classifying graphics with similar line widths and the same graphic type into the same graphic type to reduce graphic classification, wherein similar line widths refer to line widths of the same graphic type being within a preset line width window range.

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

[0012] Optionally, meshing the local area includes: dividing the original design graphic into N local areas, calculating the average line width of the N local areas in the N areas, and the average line width value of the Nth local area is w N ; N local areas are meshed separately, and the Nth area 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 .

[0013] Optionally, the auxiliary graphic feature size for defining each local area 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 to the imprinting template, and t0 is the duration of the pressure. The fluidity coefficient of the imprinting material is α=η / η0, where η is the viscosity coefficient of the imprinting 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.

[0015] Optionally, the auxiliary graphic is a 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.

[0016] Optionally, 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 , 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.

[0017] Optionally, 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.

[0018] Optionally, 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)=2h / (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.

[0019] Optionally, before step 6), the step of performing a design rule check on the overall layout after setting the auxiliary graphics is also included. If there is a problem of the auxiliary graphics overlapping or covering the effective graphics, return to step 3) to step 5) again. If the layout check is correct, the step of preparing the imprint mask is performed.

[0020] The present invention also provides a method for preparing a semiconductor device, comprising the steps of: preparing an imprint mask based on the method for preparing an imprint mask for nanoimprint lithography as described in any one of the above schemes; and preparing 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 as described in any one of the above schemes.

[0023] The present invention also provides an imprinting device, which includes 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 as described in any of the above schemes.

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

[0025] The present invention pre-corrects the nanoimprint design layout, performs intelligent grid division on the layout, divides the entire layout into multiple local areas, and evaluates the graphic duty cycle and graphic line width characteristics of the local areas. At the same time, the characteristic size of the auxiliary graphics is corrected by the imprint process factor and the imprint material fluidity coefficient. Different from the underlying logic of photolithography correction of auxiliary graphics, the present invention takes the imprint process characteristics into consideration, based on the filling rules of the layout characteristics and imprint characteristics, by adding auxiliary graphics to correct the duty cycle and layout of the entire layout, thereby improving the filling uniformity of the imprint resist and improving the uniformity of the imprint base film.

[0026] The present invention optimizes the design and adds auxiliary graphics on the imprinting plate to balance the problem of imprinting glue filling caused by the distribution of complex graphics, so that the concave parts of the imprinting plate (imprinting mold) can accommodate the imprinting material and distribute it evenly, and the imprinted design has high restoration degree and few process defects. The corrected auxiliary graphics of this method can better adapt to the line width of the local area, match the local material flow speed and filling efficiency, and optimize the local amount of glue accommodated, so that the imprinting glue can flow and fill better, thereby optimizing the uniformity of the residual glue layer thickness of the overall plate and improving the process yield.

[0027] The improvement of the imprint mask process by the present invention can expand the types of devices manufactured by the imprint mask process, improve the process yield, and break the process limitations of the current imprint process in the preparation of irregular pattern devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The included drawings are used to provide a further understanding of the embodiments of the present application, which constitute a part of the specification, are used to illustrate the implementation of the present application, and together with the text description, explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application.

[0029] Figure 1 Shown is a schematic flow chart of a method for preparing an imprint mask for nanoimprint lithography according to an embodiment of the present invention.

[0030] Figure 2 to Figure 9 Several “rectangular” exemplary schematic diagrams are shown for a method for preparing an imprint mask for nanoimprint lithography according to an embodiment of the present invention.

[0031] Fig.10 It is a schematic diagram of the enlarged structure of a local area in the method for preparing an imprint mask for nanoimprint lithography according to an embodiment of the present invention.

[0032] Figure 11 to Figure 13 It is a schematic diagram showing different sizes of auxiliary patterns corresponding to different patterns in the method for preparing an imprint mask for nanoimprint lithography according to an embodiment of the present invention.

[0033] Fig.14A schematic diagram showing a method for setting the thickness of an imprint material in a method for preparing an imprint mask for nanoimprint lithography.

[0034] Fig.15 Shown is the layout of the silicon photonic device after the traditional dummy pattern and the correction auxiliary pattern are inserted.

[0035] Figure 16-17 It is a schematic diagram showing that different regions of an imprint plate for nanoimprint lithography according to an embodiment of the present invention are provided with auxiliary patterns of different sizes, wherein: Fig.17 Display as Fig.16 Schematic diagram of the enlarged structure of the middle area.

[0036] Fig.18 Shown is an optical microscope image of an imprint of an imprint mask.

[0037] Component number description

[0038] 1 Imprinting pattern

[0039] 11 Local Area

[0040] 111 Valid graphics occupy grid

[0041] 112 blank grid

[0042] 113 Auxiliary graphics

[0043] 12 Effective graphics

[0044] 121 Trapezoid

[0045] 122 Equal width rectangles

[0046] 123 Arcs of equal width

[0047] 21 Imprinting

[0048] 22 Imprinting materials

[0049] 31 Dummy correction auxiliary graphics

[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 residual base film

[0057] 42 Filling defects DETAILED DESCRIPTION

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

[0059] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps or components.

[0060] Features described and / or illustrated with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

[0061] For example, when describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional view showing the device structure will not be partially enlarged according to the general scale, and the schematic view is only an example, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional space dimensions of length, width and depth should be included.

[0062] For ease of description, spatially relative terms such as "under", "below", "below", "below", "above", "on", etc. may be used herein to describe the relationship of one element or feature shown in the drawings to other elements or features. It will be understood that these spatially relative terms are intended to encompass other orientations of the device in use or operation in addition to the orientation 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 one or more intervening layers may also be present.

[0063] In the context of the present application, a structure in which a first feature is described as being "above" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments 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 illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and therefore the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

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

[0066] like Figure 1 As shown, firstly, step 1) is performed to provide an imprinting plate for producing an imprinting template. Figure 1 , the embossing plate Figure 1 The original design pattern includes an effective pattern 12. The effective pattern 12 may be a pattern necessary for manufacturing a device or a chip.

[0067] like Figure 1 and Figure 2 to Figure 9 , Fig.10 As shown, step 2) is then performed to extract the effective graphic 12 features of the original design graphic, define the graphic width according to the graphic type of the effective graphic 12 features, and divide the original design graphic into multiple local areas 11 according to the graphic type and graphic width.

[0068] In some embodiments, the effective graphics of the original design graphics usually have a lot of graphic width values ​​due to the complexity of the graphics. In this example, the graphic width can be defined according to the graphic type of the effective graphic 12 features, and the original design graphics can be divided into multiple local areas 11 according to the graphic type and graphic width, including: using the line width and shape characteristics of the effective graphic 12 as the basis for dividing the local area 11, wherein rectangles or combinations of rectangles with equal line widths and the same or similar shapes are regarded as a type of graphic and then divided into the same local area; the rectangle is a graphic composed of free curves (curves generated by various functions and algorithms), and the free curves are approximated, and graphics with the same or similar widths are equivalent to the following types of rectangles, and an algorithm for defining the corresponding rectangle widths is defined. Some specific examples that can be regarded as "rectangles" are as follows:

[0069] 1) A rectangle with four right angles, for example, a rectangle with a length less than 5 times the width, such as Figure 2 As shown, or a long rectangle that is longer than 5 times its width, such as Figure 3 As shown, at this time, the width of the short side of the rectangle is used as the width of the rectangle.

[0070] 2) Trapezoid, in which the height of the trapezoid or the average width between the two sides is regarded as the width of the rectangle, such as a trapezoid with a base greater than or equal to the height, such as Figure 4 As shown, in this case, the height of the trapezoid is regarded as the width of the rectangle, or the base of the trapezoid is smaller than the height, such as Figure 5 As shown, at this time, the average width between the two sides of the trapezoid is regarded as the width of the rectangle.

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

[0072] 4) Equal width arc rectangle, where the 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, such as Figure 8 and Fig. 9 shown.

[0073] 5) A ring, which is considered as a combination of 4 arc rectangles of equal width.

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

[0075] In one embodiment, the "rectangular" graphics can be arranged in the same local area in the form of rectangular combinations. Common rectangular combinations include: discrete rectangles with the number of identical rectangles <3, grating rectangle combinations with the number of identical rectangles ≥3, and overlapping combinations of multiple rectangles.

[0076] In one embodiment, dividing the original design graphic into a plurality of local areas 11 according to the graphic type and the graphic width includes the steps of: dividing the graphics with similar line width and the same graphic type into the same graphic type to reduce the classification of graphics, wherein the similar line width means that the line width of the same graphic type is within a preset line width window range, such as Fig.10 As shown, Fig.10 Effective Fig.12 The shapes include a) arc shapes 123 of equal width, and two arc shapes are combined to form a semicircle as the first type of rectangle, b) long rectangles 122 of equal width, and two long rectangles arranged alternately on the upper and lower sides are combined to form a second type of rectangle, and c) trapezoids 121, and two trapezoids arranged alternately on the upper and lower sides are combined to form a third type of rectangle. Then, the three adjacent rectangles are judged to have similar line widths, so the areas of the three rectangles can be combined as the same local area.

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

[0078] like Figure 1 and Fig.10 As shown, step 3) is then performed to mesh the local area 11, and the average line width of the effective graphics 12 in the local area 11 is calculated, and the duty cycle of the effective graphics 12 in the local area 11 is calculated according to the number of grids 111 occupied by the effective graphics 12.

[0079] In one embodiment, the duty cycle of the effective pattern 12 is defined as: a local area 11 is divided into n grids n N , the number of grids in the local area 11 occupied by the grid 111 containing the effective pattern 12 is x, and the grid without the effective pattern 12 is the blank grid 112, then the local duty ratio of the Nth area is θ N =x N / n N , where the subsequent local duty cycle θ N <θ max The auxiliary pattern 113 is inserted into the blank grid 112 of the local area 11, where θ max is the optimal local duty cycle of the local area 11. That is, when the local duty cycle is less than the optimal local duty cycle, an auxiliary graphic 113 can be inserted into the blank grid 112 of the local area, so that the ratio between the raised graphics and the recessed graphics in the local area 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 thickness of the base film is 0, the ideal optimal local duty cycle is 50%. In one embodiment, meshing the local area 11 includes: dividing the original design graphic into N local areas 11, calculating the average line width of the N local areas 11 in the N areas, and the average line width value of the Nth local area 11 is w N ; N local regions 11 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 11 N .

[0080] like Figure 1 , Fig.10 and Figure 11 to Figure 13As shown, step 4 is then performed to define the characteristic size of the auxiliary pattern 113 of each local area 11 according to the average line width of the effective pattern 12 and the viscosity coefficient of the imprint material.

[0081] In one embodiment, the characteristic dimensions of the auxiliary graphics 113 defining each local area 11 include:

[0082] 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 to the imprinting template, and t0 is the duration of the pressure. The fluidity coefficient of the imprinting material is α=η / η0, where η is the viscosity coefficient of the imprinting material used; the characteristic size of the auxiliary pattern 113 of the local area 11 is defined 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, Fig.11 As shown, for a rectangle with a uniform line width of wa, assuming that the fluidity coefficient α of the imprint material is 1, the characteristic size of each auxiliary pattern 113 is also wa; Fig.12 As shown, for a combination of rectangles with average line widths wa and wb, the characteristic size wc of each auxiliary pattern 113 is related to wa and wb. Here, the characteristic size wc of the auxiliary pattern 113 is the average of the two rectangles according to their proportions, and wc is between wa and wb; Fig.13 As shown, for a combination of rectangles with different line widths (wa, wd and we), the characteristic size wf of each auxiliary graphic 113 is related to wa, wd and we, where wf is the average of multiple rectangles according to their proportions. Since we occupies a larger area, it has a greater impact on the average, so the characteristic size wf of the auxiliary graphic 113 is larger than wa and wd, but smaller than we.

[0083] In one embodiment, the auxiliary pattern 113 has a length and a width. N Of course, in other embodiments, the auxiliary pattern 113 can also be a rectangle with a length and a width. N The area of ​​a rectangle is equal to that of a circle or an equilateral polygon with more than five sides.

[0084] like Figure 1 , Fig.10 and Figure 11 to Figure 13 As shown, then step 5) is performed, in which auxiliary graphics 113 are set in the local area 11 according to the duty cycle of the local area 11 and the characteristic size of the auxiliary graphics 113. The auxiliary graphics 113 in the same local area 11 have the same shape and size. The auxiliary graphics 113 are placed at the center of each grid in the blank area of ​​the local area to balance the uneven distribution of the effective graphics 12. Figure 1 The (embossing mold) is provided with a groove (corresponding to a convexity on the embossing colloid), and the auxiliary pattern 113 is formed on the embossing plate Figure 1 (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 excess imprinting colloid. Assuming that when the line width of a finite pattern is very small, there is residual glue left after the imprinting colloid fills the pattern. When the line widths of various regions are different, the thickness of the residual glue will be uneven. The auxiliary pattern of the groove provided in the present invention can accommodate excess imprinting colloid. By controlling the line width of the auxiliary pattern so that it is the same or similar to the value after multiplying the average line width value of the effective pattern by the fluidity coefficient, the auxiliary pattern can be made more effective and more uniform to accommodate excess imprinting colloid. At the same time, by setting the auxiliary pattern so that it and the effective pattern together form a groove pattern, the final duty ratio of the groove pattern and the protrusion pattern in the local area is finally adjusted to be controlled to the optimal duty ratio, so that the thickness of the residual base film after imprinting is 0 or close to 0.

[0085] In one embodiment, setting the auxiliary pattern 113 includes: sequentially calculating the local duty ratios of the N local areas 11 , and repeatedly inserting the auxiliary pattern 113 in the first to the Nth local areas 11 .

[0086] In one embodiment, the step of performing a design rule check on the overall layout after setting the auxiliary graphic 113 is also included. If there is a problem that the auxiliary graphic 113 overlaps or covers the effective graphic 12, returning to step 3) to step 5) again. If the layout check is correct, the step of preparing the imprint mask is performed.

[0087] In one embodiment, before preparing the imprint mask, a step of setting the thickness of the imprint material 22 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 21, s2 is the area of ​​the convex pattern area on the imprint plate 21, H is the ideal groove pattern etching depth, and h is the thickness of the imprint material 22 required before imprinting.

[0088] Specifically, Fig.14 As shown, s1 is the area of ​​the concave pattern area on the imprint plate 21, s2 is the area of ​​the convex pattern area on the imprint plate 21, H is the ideal groove pattern etching depth, h is the required glue layer thickness before imprinting, and h2' is the residual glue layer thickness after imprinting, then:

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

[0090] The glue coating thickness before embossing is given by formula 2: h = h2 + h2';

[0091] The plate duty ratio of the prepared imprint plate is given by Formula 3: s1 / (s1+s2);

[0092] Based on the principle that the volume of the imprinted adhesive layer is constant, we can obtain equation 4: s2h2 = s1h1;

[0093] Substituting equation 1 into equation 4, we can obtain equation 5: s2h2 = s1(H-h2);

[0094] By moving the terms in equation 5, we can get equation 6: (s1+s2)h2=s1H;

[0095] Substituting equation 2 into equation 6, we can obtain equation 7: (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 rubber layer can be calculated based on the plate duty ratio of the prepared imprinted plate. At the same time, it can be seen that the plate duty ratio is a factor that affects the filling of the imprinted colloid. In an ideal situation, when the colloid has excellent fluidity, when s1=s2, h=H / 2, the colloid can be completely filled without any bottom film residue.

[0097] Finally, step 6) is performed, according to the stamping plate after the auxiliary pattern 113 is set Figure 1 , prepare an imprint mask.

[0098] Figure 11 to Figure 13 Auxiliary graphics showing several local areas, by Figure 11 to Figure 13 It can be seen that the auxiliary graphics matched by different effective graphic combinations are of different sizes. Since the distribution of the imprinted pattern may be uneven and the line width of the pattern may also be uneven when the imprint lithography process is expanded to more application scenarios, the auxiliary graphics of the present invention can better adapt to the line width of the local area, match the glue flow speed and filling efficiency of the local area, and optimize the amount of glue contained in the local area, so that the imprinted glue can flow and fill better. Therefore, the uniformity of the residual glue layer thickness of the overall imprinted pattern can be optimized, and the process yield can be improved.

[0099] Attached Fig.15 The layout for a silicon photonic device is shown, which includes an effective pattern 12, a layout after a traditional Dummy pattern and a correction auxiliary pattern 31 are inserted. The size of the traditional Dummy pattern is defined according to the layout duty cycle. The Dummy pattern is a uniform pattern array, such as Fig.15 as shown; Fig.16 and Fig.17 As shown, Fig.17 Display as Fig.16The enlarged structural diagram of the middle area, the auxiliary graphics defined in the present invention are uneven between different areas in the entire layout, the auxiliary graphics size is defined according to the effective graphic features of the local area, and the size value is corrected according to the characteristics of the embossing glue used, and it can be divided into the first local area 32, the second local area 33, the third local area 34, the fourth local area 35, the fifth local area 36, ​​and the sixth local area 37, wherein, according to the type and line width distribution of the effective graphics, the first local area 32 and the fourth local area 35 can be merged, the second local area and the fifth local area 36 can be merged, and the third local area 34 and the sixth local area 37 can also be merged, and finally three local areas of different auxiliary graphics sizes are formed. Compared with the uniform Dummy graphics in the traditional layout, the auxiliary graphics of the present invention can better accommodate the filling of the embossing glue and improve the process yield.

[0100] Attached Fig.18 An optical microscope image of the imprint mask is shown, comparing the area with auxiliary graphics and the area without auxiliary graphics. Significant residual base film uniformity difference 41 and filling defects 42 appear near the area without auxiliary graphics, which mainly appear as color difference during imaging, indicating that inserting auxiliary graphics in the present invention can optimize the uniformity problem of the imprint base film.

[0101] This embodiment also provides a method for preparing a semiconductor device, comprising the steps of: preparing an imprint mask based on the method for preparing an imprint mask for nanoimprint lithography as described in any of the above schemes; and preparing 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, semiconductor devices are not limited to the examples listed above, and semiconductor devices can also be expanded to power semiconductor devices, storage devices, logic devices, etc.

[0103] This embodiment further provides an imprint mask, which is prepared based on the method for preparing an imprint mask for nanoimprint lithography as described in any one of the above solutions.

[0104] This embodiment also provides an imprint device, which includes 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 as described in any of the above schemes.

[0105] The processor may 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 hardware chip may be an application specific integrated circuit (ASIC), a programmable logic device (PLD) or a combination thereof. The programmable logic device (PLD) may be a complex programmable logic device (CPLD), a field programmable gate array (FPGA), a general array logic (GAL) or any combination thereof.

[0106] The memory is connected to the processor through a bus or other means, and at least one instruction, at least one program, code set or instruction set is stored in the memory. The 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 for nanoimprint lithography as in the embodiment 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 (flash), 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 for nanoimprint lithography and the preparation method thereof of the present invention have the following beneficial effects:

[0108] The present invention pre-corrects the nanoimprint design layout, performs intelligent grid division on the layout, divides the entire layout into multiple local areas, and evaluates the graphic duty cycle and graphic line width characteristics of the local areas. At the same time, the characteristic size of the auxiliary graphics is corrected by the imprint process factor and the imprint material fluidity coefficient. Different from the underlying logic of photolithography correction of auxiliary graphics, the present invention takes the imprint process characteristics into consideration, based on the filling rules of the layout characteristics and imprint characteristics, by adding auxiliary graphics to correct the duty cycle and layout of the entire layout, thereby improving the filling uniformity of the imprint resist and improving the uniformity of the imprint base film.

[0109] The present invention optimizes the design and adds auxiliary graphics on the imprinting plate to balance the problem of imprinting glue filling caused by the distribution of complex graphics, so that the concave parts of the imprinting plate (imprinting mold) can accommodate the imprinting material and distribute it evenly, and the imprinted design has high restoration degree and few process defects. The corrected auxiliary graphics of this method can better adapt to the line width of the local area, match the local material flow speed and filling efficiency, and optimize the local amount of glue accommodated, so that the imprinting glue can flow and fill better, thereby optimizing the uniformity of the residual glue layer thickness of the overall plate and improving the process yield.

[0110] The improvement of the imprint mask process by the present invention can expand the types of devices manufactured by the imprint mask process, improve the process yield, and break the process limitations of the current imprint process in the preparation of irregular pattern 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 merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall 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) Prepare an imprint mask according to the imprint pattern after setting the auxiliary pattern.

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 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.

7. The method for preparing an imprint mask for nanoimprint lithography according to claim 6, 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.

8. The method for preparing an imprint mask for nanoimprint lithography according to claim 1, characterized in that: 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 , 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.

9. The method for preparing an imprint mask for nanoimprint lithography according to claim 8, 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.

10. 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.

11. 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.

12. 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 11; A semiconductor device is manufactured based on the imprint mask.

13. The method for preparing a semiconductor device according to claim 12, 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.

14. 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.

15. An imprinting device, characterized in that: The imprinting device includes 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 11.

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