Droplet formulation generation method, imprint method, and semiconductor device manufacturing method

Abstract

The embodiment of the invention relates to a droplet formula generating method, an imprint method and a semiconductor device manufacturing method. According to one embodiment of the present invention, a droplet formulation generation method acquires first information indicating a position of a step in a first exposure region including the step among a plurality of exposure regions provided on a substrate, and second information indicating a position of an outer edge portion of the substrate, and generates a droplet formulation on the basis of the acquired first information and second information. The droplet formulation is changed before change in which the dropping position of the plurality of droplets onto the substrate is set to a uniform density, and the droplet formulation is changed after the change in which the dropping position of the plurality of droplets onto the substrate is set to a uniform density, and the droplet formulation is changed after the change in which the dropping position of the plurality of droplets onto the substrate is set to a uniform density. In the first region and the second region defined by the third information and the fourth information, there are no droplets, and the density of droplets located near the inner side of the first position is higher than the density of droplets located inside the first position other than near the inner side.

Description

[0001] Related applications

[0002] This application claims the benefit of priority based on Japanese Patent Application No. 2024-040431 (filing date: March 14, 2024), the entire contents of which are incorporated herein by reference. Technical Field

[0003] Embodiments of the present invention relate to a method for generating a droplet formulation, an imprinting method, and a method for manufacturing a semiconductor device. Background Art

[0004] The manufacturing process of semiconductor devices sometimes includes an imprint process. During the imprint process, the template pattern is transferred to a resist material, etc., applied to the exposure area of ​​the substrate. The periphery of the substrate may contain defective exposure areas, where a portion of the exposure area is missing. The location and area of ​​the defects in each defective exposure area may vary. Applying the same amount of resist material and placement as for the normal exposure area to the defective exposure area can result in malfunctions in the imprint process. Summary of the Invention

[0005] The method for generating a droplet formula of the embodiment is used for imprint processing of a substrate having a step difference on its outer periphery, and obtains first information indicating the position of the step difference in a first exposure area including the step difference among multiple exposure areas of the substrate, and second information indicating the position of the outer edge of the substrate, and sets third information indicating a first area between the step difference and the outer edge of the substrate based on the obtained first and second information, and sets fourth information based on the first information, the fourth information indicating a second area between a first position entering a first distance from the step difference to the inner side of the substrate and the step difference, and changes the droplet formula before the change in which the droplet addition position of multiple droplets to the substrate is set to a uniform density, so that no droplets exist in the first area and the second area specified by the third and fourth information, and the density of droplets located near the inner side of the first position is higher than the density of droplets located inside the first position except near the inner side.

[0006] According to one embodiment, a method for producing a droplet formulation, an imprint method, and a method for manufacturing a semiconductor device that can suppress the occurrence of defects in a defective exposure region can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a schematic diagram showing an example of the configuration of an imprint apparatus according to an embodiment.

[0008] Figure 2A and Figure 2B Schematic diagram showing an example of the configuration of a wafer processed by the imprint apparatus according to the embodiment.

[0009] Figures 3A to 3D 1 is a cross-sectional view sequentially illustrating a portion of steps in a process for removing edge beads from a wafer according to an embodiment.

[0010] Figures 4A to 4C These are cross-sectional views sequentially illustrating a portion of steps of an imprint process performed by the imprint apparatus according to the embodiment.

[0011] Figures 5A to 5C These are cross-sectional views sequentially illustrating a portion of steps of an imprint process performed by the imprint apparatus according to the embodiment.

[0012] Figures 6A to 6C The diagram is a cross-sectional view sequentially illustrating a portion of the steps of etching a target layer according to an embodiment.

[0013] Figures 7A to 7F This is a schematic diagram for explaining a method for correcting a droplet recipe using the imprint apparatus according to the embodiment.

[0014] Figure 8 This is a flowchart showing an example of the procedure of an imprint process performed by the imprint apparatus according to the embodiment.

[0015] Figures 9A to 9F It is a cross-sectional view illustrating the steps of an imprint process performed by an imprint apparatus of a comparative example. DETAILED DESCRIPTION

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the present invention is not limited to the following embodiments. In addition, the constituent elements in the following embodiments include elements that can be easily assumed by the industry or are substantially the same.

[0017] (Configuration Example of Imprint Device)

[0018] Figure 1 It is a schematic diagram showing an example of the configuration of the imprint apparatus 1 according to the embodiment.

[0019] like Figure 1 As shown, the imprint apparatus 1 includes a template stage 81 , a wafer stage 82 , imaging elements 83 and 84 , reference marks 85 , an alignment unit 86 , a liquid dropping device 87 , a stage base 88 , a light source 89 , and a control unit 90 .

[0020] The imprint apparatus 1 can be mounted with a template 10 for transferring a pattern to a resist on a wafer 20. Various processes, including those using the imprint apparatus 1, are performed on the wafer 20 to manufacture semiconductor devices. The wafer 20 may be a semiconductor substrate, an insulating substrate, or a conductive substrate.

[0021] The wafer stage 82 includes a wafer chuck 82b and a main body 82a. The wafer chuck 82b is configured as a suction cup that attracts the wafer 20 and holds it at a predetermined position on the main body 82a. Reference marks 85 are provided on the wafer stage 82. The reference marks 85 are used for positional alignment when the wafer 20 is placed on the wafer stage 82.

[0022] The wafer stage 82 carries the wafer 20 and moves in a plane (horizontal plane) parallel to the carried wafer 20. When the resist is dripped onto the wafer 20, the wafer stage 82 moves the wafer 20 toward the lower side of the liquid dripping device 87, and when the transfer process is performed on the wafer 20, the wafer 20 moves toward the lower side of the template 10.

[0023] The stage base 88 supports the template 10 via the template stage 81 and moves in the up-down direction (vertical direction), thereby pressing the pattern of the template 10 against the resist on the wafer 20 .

[0024] An alignment unit 86 including a plurality of imaging elements 83 is provided on the stage base 88. The alignment unit 86 detects the position of the wafer 20 and the position of the template 10 based on alignment marks provided on the wafer 20 and the template 10, respectively.

[0025] The alignment unit 86 includes a detection system 86a and an illumination system 86b. The illumination system 86b illuminates the wafer 20 and template 10 to make the alignment marks formed thereon visible. The detection system 86a detects the images of the alignment marks and aligns them, thereby aligning the wafer 20 and template 10.

[0026] The detection system 86a and the illumination system 86b respectively include mirrors 86x and 86y such as dichroic mirrors as imaging units. The mirrors 86x and 86y use light from the illumination system 86b to form images of alignment marks and other images on the wafer 20 and the template 10.

[0027] Specifically, mirror 86y reflects light Lb from illumination system 86b toward the bottom where wafer 20 and the like are positioned. Furthermore, mirror 86x reflects light La from wafer 20 and the like toward detection system 86a. Furthermore, a portion of light Lc from wafer 20 and the like passes through mirrors 86x and 86y and travels toward imaging element 83 above.

[0028] The imaging element 83 captures the portion of light Lc as an image including alignment marks, etc. The image captured by the imaging element 83 is analyzed by the control unit 90 to perform position alignment between the wafer 20 and the template 10 .

[0029] On the other hand, the light La reflected by the mirror 86 x toward the detection system 86 a travels toward the imaging element 84 included in the detection system 86 a .

[0030] The imaging element 84 captures the light La reflected by the mirror 86 x as an image including the alignment mark, etc. The image captured by the imaging element 84 is analyzed by the control unit 90 to perform position alignment between the wafer 20 and the template 10 .

[0031] The liquid dropper 87 drops resist onto the wafer 20 using an inkjet method. The liquid dropper 87 includes an inkjet head having a plurality of fine holes for ejecting resist droplets, and drops the resist droplets onto the exposure area on the wafer 20 .

[0032] The light source 89 is a device that irradiates light such as ultraviolet light for curing the resist, and is provided above the stage base 88. The light source 89 irradiates light from the template 10 while the template 10 is pressed against the resist.

[0033] The control unit 90 is configured as a computer including, for example, a hardware processor such as a CPU (Central Processor), a memory, and an HDD (Hard Disk Drive). The control unit 90 controls the template stage 81, the wafer stage 82, the fiducial mark 85, the alignment unit 86 including imaging elements 83 and 84, the liquid dropping device 87, the stage base 88, and the light source 89.

[0034] Next, use Figure 2A and Figure 2B , a configuration example of the wafer 20 to be processed by the imprint apparatus 1 will be described.

[0035] Figure 2A and Figure 2B 1 is a schematic diagram showing an example of the structure of a wafer 20 processed by the imprint apparatus 1 according to the embodiment. Figure 2A and Figure 2B The upper portion of each figure is a top view of the wafer 20 , and the lower portion is a cross-sectional view of the side surface of the wafer 20 .

[0036] like Figure 2A and Figure 2B As shown, wafer 20 has a convex region 21 having multiple layers stacked on its periphery. Prior to processing using imprint apparatus 1, wafer 20 has been subjected to multiple processes, for example. The multiple layers in convex region 21 may include insulating layers, conductive layers, semiconductor layers, and the like formed by these processes.

[0037] The outer periphery of wafer 20 is provided with an edge region 23 created by removing these layers. By removing some or all of the multiple layers that comprise convex region 21, the surface of wafer 20, such as a silicon substrate, is exposed in edge region 23. Furthermore, this causes convex region 21 to protrude from the surface of wafer 20, and wafer 20 has a step 22 at the boundary between convex region 21 and edge region 23, which decreases from convex region 21 toward edge region 23. The height of this step 22 is, for example, on the order of microns.

[0038] The step 22 of the wafer 20 forms a circular ring around the periphery of the wafer 20. The convex region 21, which is demarcated from the edge region 23 by the step 22, has a shape roughly similar to that of the wafer 20 and is a circular region when viewed from the top surface of the wafer 20. However, the center point of the convex region 21, when viewed from the top surface of the wafer 20, does not necessarily coincide with the center point of the wafer 20.

[0039] Figure 2A This is an example of a case where the center point of the convex region 21 does not coincide with the center point of the wafer 20. Figure 2A In the example, the convex region 21 is eccentric to the lower right of the paper relative to the wafer 20. Therefore, the width of the edge region 23 varies according to the peripheral position of the wafer 20. Figure 2A In the example, the width of the edge region 23 is the largest at the upper left peripheral position of the paper, and the width of the edge region 23 is the smallest at the lower right peripheral position of the paper.

[0040] Figure 2B This is an example of a case where the center point of the convex region 21 coincides with the center point of the wafer 20 . In this case, the width of the edge region 23 is substantially constant at any peripheral position of the wafer 20 .

[0041] Furthermore, the upper surface of wafer 20 is divided into a plurality of exposure areas SH (SHe, SHc) by the previous processing. The plurality of exposure areas SH are arranged in a grid pattern over substantially the entire surface of wafer 20. Among these exposure areas SH, exposure areas SHe arranged in areas other than the outer periphery of wafer 20 each have, for example, a rectangular shape. On the other hand, portions of several exposure areas SHc arranged in the outer periphery of wafer 20 are defective exposure areas that extend beyond convex areas 21.

[0042] These exposure areas SH serve as processing units in several steps of the semiconductor device manufacturing process, including the imprint process. Specifically, in the imprint process described below, for example, the pattern of the transfer template 10 is transferred to each exposure area SH. At the final stage of the semiconductor device manufacturing process, one or more semiconductor chips are obtained from each exposure area SH, thereby obtaining one or more semiconductor devices.

[0043] The plurality of exposure areas SH arranged in a grid pattern on the wafer 20 are formed so that the center point of the entire exposure area SH coincides with the center point of the wafer 20. Therefore, there is a case where the convex area 21 of the wafer 20 is also eccentric relative to the plurality of exposure areas SH. Figure 2A The example shown is that the convex area 21 is not eccentric with respect to the exposure area SH. Figure 2B In the example shown, the relative positional relationship between the step 22 and each exposure region SH is different, and accordingly, the area and shape of the exposure regions SHc on the outer periphery of the wafer 20 are different.

[0044] (Method for Manufacturing Semiconductor Device)

[0045] Next, use Figures 3A to 7F The manufacturing process of the semiconductor device of the embodiment includes edge bead removal (EBR) of the wafer 20 and imprint processing using the imprint apparatus 1 described above.

[0046] Figures 3A to 3D 1 and 2 are cross-sectional views sequentially illustrating a portion of steps in a process for removing edge beads from a wafer 20 according to an embodiment.

[0047] like Figure 3A As shown in FIG. 1 , through the previous processing, a plurality of layers 30, such as an insulating layer, a conductive layer, and a semiconductor layer, are formed on the wafer 20 that is the target of the imprint processing. As described above, when the formation processing of various layers is repeated multiple times, edge beads 30e, where the thickness of the plurality of layers 30 is thickened as a whole, may sometimes be generated on the periphery of the wafer 20. The edge beads 30e may sometimes cause various defects in subsequent processing. Therefore, it is preferable to appropriately remove them at a specified time as shown below.

[0048] like Figure 3B As shown, a photoresist layer 100 is formed on the plurality of layers 30 to cover the entire surface of the wafer 20 .

[0049] like Figure 3C As shown, the photoresist layer 100 of the outer periphery of the wafer 20 is removed by a predetermined width to form a resist pattern 100p. This exposes the outer periphery of the plurality of layers 30 including the edge beads 30e.

[0050] For example, the photoresist layer 100 on the periphery of the wafer 20 is removed by performing an exposure process on the periphery of the wafer 20 , or by spraying a removal liquid that dissolves the photoresist layer 100 on the periphery of the wafer 20 .

[0051] The exposure process for the outer periphery of the wafer 20 is performed on the photoresist layer 100 before exposure and development. Specifically, for example, while the wafer 20 is rotated on a spinner with the center point of the wafer 20 as the rotation axis when viewed from the top surface, the outer periphery is irradiated with exposure light such as a laser. This exposes a predetermined width of the photoresist layer 100 on the outer periphery of the wafer 20, which is then removed by development.

[0052] The dissolution process of the photoresist layer 100 is performed on the photoresist layer 100 after the exposure and development processes. Specifically, as described above, the wafer 20 is rotated on a spinner with its center as the axis of rotation, while a removal liquid is sprayed toward the periphery. This dissolution removes a predetermined width of the photoresist layer 100 from the periphery of the wafer 20.

[0053] Furthermore, when using any of the above methods, when the wafer 20 is held on a spinner, for example, there is a possibility of a slight misalignment between the spinner's rotation axis and the center point of the wafer 20. In this case, the center point of the resist pattern 100p, from which the peripheral portion has been removed, will not align with the center point of the wafer 20, causing the resist pattern 100p to be eccentric relative to the wafer 20. Furthermore, the width of the photoresist layer 100 removed from the peripheral portion of the wafer 20 will vary depending on the peripheral position of the wafer 20.

[0054] like Figure 3D As shown, the plurality of layers 30 exposed from the resist pattern 100p are etched to remove edge beads 30e formed on the plurality of layers 30. In other words, the surface layer of the substrate exposed from the resist pattern 100p is removed. At this point, the etching process may be continued until all of the plurality of layers 30 on the wafer 20 are removed, exposing the surface of the wafer 20. Alternatively, the upper layers of the plurality of layers 30 may be removed, while the lower layers remain on the wafer 20.

[0055] By the above operation, the edge region 23 a formed by removing the plurality of layers 30 and the convex region 21 a convexly raised relative to the edge region 23 a are formed on the wafer 20 . Furthermore, a step 22 a is formed between the edge region 23 a and the convex region 21 a .

[0056] Furthermore, when the resist pattern 100 p is formed off-center with respect to the wafer 20 , the convex region 21 is also formed off-center with respect to the wafer 20 .

[0057] The edge bead removal process described above is appropriately performed at any time during the semiconductor device manufacturing process. Therefore, the edge bead removal process may be performed one or more times at a predetermined time point before the imprint process is performed. In this case, the imprint process may be performed immediately after the edge bead removal process or after several steps have passed since the edge bead removal process.

[0058] At this time, the convex region 21 a , the step 22 a , and the edge region 23 a are also inherited by the wafer 20 to be processed, and the wafer 20 to be processed has the convex region 21 , the step 22 , and the edge region 23 .

[0059] Figures 4A to 5C 1 and 2 are cross-sectional views sequentially illustrating a part of the steps of an imprint process performed by the imprint apparatus 1 according to the embodiment.

[0060] When the imprint process starts, the template 10 and the wafer 20 are loaded into the imprint apparatus 1 , the template 10 is mounted on the template stage 81 , and the wafer 20 is mounted on the wafer stage 82 .

[0061] like Figure 4A As shown, in the wafer 20 loaded into the imprinting device 1, a processed layer 40 covering multiple layers 30 subjected to edge bead removal treatment, an SOC (Spin On Carbon) layer 50 and an SOG (Spin On Glass) layer 60 are formed sequentially from the side of the wafer 20, for example, on the entire surface of the wafer 20.

[0062] The processed layer 40 is a layer processed into a pattern to be transferred to the wafer 20 by an imprint process, and is, for example, an insulating layer such as a silicon oxide layer. The SOC layer 50 is an organic layer containing carbon as a main raw material. The SOG layer 60 is an inorganic layer such as a silicon oxide layer. Both the SOC layer 50 and the SOG layer 60 are formed by, for example, spin coating.

[0063] The wafer 20 has a step 22a due to the edge bead removal process. The layers are formed along the step 22a in the convex region 21a, the step 22a, and the edge region 23a. Therefore, each layer also forms a step 22, and has a convex region 21 and an edge region 23 with the step 22 as the boundary.

[0064] As described above, a plurality of shot regions SH are provided on the wafer 20 on which these layers are formed. The imprint apparatus 1 sequentially performs the following imprint processing on these shot regions SH.

[0065] The liquid droplet device 87 of the imprint apparatus 1 drops droplets 110d of a resist material or the like onto the exposure area SH to be processed among the plurality of exposure areas SH. The resist material droplets 110d are, for example, photocurable photoresist, and are dropped onto the wafer 20 in a liquid state before curing. As a result, the plurality of droplets 110d are dispersed throughout the exposure area SH.

[0066] The imprint device 1 stores a droplet recipe that specifies the amount of droplets 110d to be dropped onto the exposure area SH, the number of drops to be dropped, and the droplet placement. The droplet placement is specified in the droplet recipe, for example, so that the droplets are dropped onto the rectangular exposure area SHe without defects at a predetermined period such as a sawtooth pattern or a grid pattern when viewed from the top surface (see FIG. Figure 2A and Figure 2B That is, the dropping positions of the individual droplets 110d set in the droplet recipe allow the droplets to be dropped theoretically over the entire area of ​​the exposure area SHe, for example, with a substantially uniform density.

[0067] In addition, in this specification, "substantially" uniform includes not only the case where the density of the droplets 110d specified in the droplet recipe is completely uniform, but also the case where there is a specified deviation.

[0068] However, even when the droplets 110d are dropped using a droplet recipe set so that the droplets 110d have a uniform density as described above, the density of the droplets 110d actually dropped onto the wafer 20 may not be completely uniform. The actual density of the droplets 110d on the wafer 20 may vary within a specified range due to factors such as the dropping accuracy of the liquid dropping device 87, the driving accuracy of the wafer stage 82, and the flatness of the wafer 20.

[0069] In addition, among the plurality of exposure regions SH, an exposure region SHc (see FIG. Figure 2A and Figure 2B ) is the target of imprint processing, after appropriately correcting the droplet recipe defined based on the exposure area SHe without defects, droplets 110d are dropped. The details of the method for correcting the droplet recipe will be described below.

[0070] like Figure 4B As shown, after a plurality of droplets 110d are dropped onto the exposure area SH to be processed according to the droplet recipe, the template 10 carried into the imprint apparatus 1 and mounted on the template stage 81 is arranged at a position vertically opposite to the exposure area SH.

[0071] The template 10 is mounted on the template stage 81 with the surface having the designated pattern 10p facing the wafer 20. The pattern 10p provided on the template 10 can be appropriately changed according to the pattern to be formed on the processing layer 40, such as a line and space pattern, a dot pattern, or a hole pattern.

[0072] As described above, with the template 10 facing the wafer 20 at a predetermined distance, rough alignment is performed by observing alignment marks provided on the template 10 and the wafer 20 using, for example, the imaging element 83 of the imprint apparatus 1 .

[0073] As described above, the rough alignment is a process of roughly aligning the template 10 and the wafer 20 so that the alignment marks provided thereon overlap with each other while the template 10 and the wafer 20 are separated from each other.

[0074] like Figure 4C As shown, after the rough alignment is completed, the pattern 10p of the template 10 is brought into contact with the plurality of droplets 110d on the wafer 20. At this time, the template 10 is held above the wafer 20 with a small gap between it and the uppermost SOG layer 60 of the wafer 20.

[0075] Furthermore, after this, until the imprint process is completed, the template 10 is maintained at a height position slightly spaced from the wafer 20. This prevents the template 10 from contacting the wafer 20 and damaging the wafer 20.

[0076] The droplets 110d are compressed and expanded by pressing against the template 10, forming a resist layer 110s in which the droplets 110d are substantially integrated. In addition, a portion of the resist layer 110s gradually fills the concave and convex portions of the pattern 10p provided on the template 10 by capillary action.

[0077] This is observed, for example, by the imaging element 83 . When the resist layer 110 s is substantially completely filled with the unevenness of the pattern 10 p , alignment marks provided on the template 10 and the wafer 20 are observed, for example, by the imaging element 84 , to perform fine alignment.

[0078] As described above, fine alignment is a process of more precisely aligning the template 10 by sliding it along the surface of the wafer 20 while in contact with the resist layer 110 s so that alignment marks provided on the template 10 and the wafer 20 overlap.

[0079] Furthermore, fine alignment is performed after the resist layer 110s is filled into the concavo-convex portions of the pattern 10p. This improves the visibility of the alignment marks because the concavo-convex portions of the pattern 10p are completely filled. However, filling the concavo-convex portions of the pattern 10p with the resist layer 110s and fine alignment can also be performed simultaneously. This can improve the throughput of the imprint process.

[0080] like Figure 5A As shown, after fine alignment is completed, the light source 89 of the imprint apparatus 1 irradiates ultraviolet light or the like from above the template 10 to cure the resist layer 110s. Thus, the pattern 10p of the template 10 is transferred to the resist layer 110s, forming a resist pattern 110p.

[0081] like Figure 5B As shown, the template 10 is released from the resist pattern 110 p.

[0082] like Figure 5CAs shown, the above-described imprint process is sequentially performed on a plurality of exposure areas SH on the wafer 20, forming a resist pattern 110p in each exposure area SH. Furthermore, the resist pattern 110p is formed with a resist residue 110r at the bottom between the patterns. As described above, during the imprint process, the template 10 is maintained at a height position with a slight gap between it and the wafer 20, resulting in the formation of the resist residue 110r.

[0083] When the imprint process for all the exposure areas SH provided on the wafer 20 is completed, the template 10 and the wafer 20 are unloaded from the imprint apparatus 1. The wafer 20 unloaded from the imprint apparatus 1 is moved to Figures 6A to 6C The processing shown.

[0084] Figures 6A to 6C 1 and 2 are cross-sectional views sequentially illustrating a portion of the steps of etching the target layer 40 according to the embodiment.

[0085] like Figure 6A As shown, the resist residue 110 r of the resist pattern 110 p is removed by using a method such as reactive ion etching (RIE), and the exposed SOG layer 60 is etched to form an SOG pattern 60 p to which the resist pattern 110 p is transferred on the SOG layer 60 .

[0086] like Figure 6B As shown, the SOC layer 50 is etched using a method such as RIE, using the SOG pattern 60p as a mask, to form an SOC pattern 50p to which the SOG pattern 60p is transferred on the SOC layer 50. The resist pattern 110p and the SOC layer 50 are composed of similar materials, so that at least the resist pattern 110p disappears by the etching process of the SOC layer 50.

[0087] like Figure 6C As shown, the processed layer 40 is further etched using the SOC pattern 50p as a mask using a method such as RIE, thereby forming a pattern 40p to which the SOC pattern 50p is transferred on the processed layer 40. The SOC pattern 50p is then removed by ashing using oxygen plasma or the like.

[0088] Thereafter, for example, when the processing layer 40 is an insulating layer, a conductive layer is embedded in the pattern 40p of the processing layer 40 to form wiring or vias. By repeating the above-described process multiple times, the semiconductor device of the embodiment is manufactured.

[0089] In the above example, the processing layer 40 is assumed to be an insulating layer, etc. However, the processing layer 40 may also be another type of layer, such as a conductive layer or a semiconductor layer. Furthermore, after the SOC layer 50 and the SOG layer 60 are formed on the processing layer 40, it is assumed that the resist pattern 110p is formed as the target of the imprint process. However, the layer structure used when processing the processing layer 40 is not limited to the above.

[0090] As described above, the wafer 20 includes exposure regions SHe, which are located in areas other than the periphery of the wafer 20 and do not have defects, and exposure regions SHc, which are located in the periphery of the wafer 20 and have defects. Furthermore, the convex region 21, which includes the plurality of layers 30 that have undergone edge bead removal processing, may be eccentric relative to the entirety of the plurality of exposure regions SH. Therefore, the shape and area of ​​the exposure region SHc may vary from wafer to wafer 20.

[0091] On the other hand, the droplet recipe of the imprint apparatus 1 is defined based on, for example, shot areas SHe without defects. Therefore, in the imprint process of the embodiment, when processing shot areas SHc with defects, the control unit 90 of the imprint apparatus 1 corrects the droplet recipe in accordance with each shot area SHc.

[0092] Figures 7A to 7F This is a schematic diagram illustrating a method for generating a droplet recipe using the imprint apparatus 1 of the embodiment. The method for generating a droplet recipe is performed, for example, in the control unit 90 of the imprint apparatus 1, and the droplet recipe is corrected for each shot area SHc.

[0093] Figures 7A to 7E This is an example of an image 83a obtained by photographing a designated exposure area SHc provided on the wafer 20 using the imaging element 83. More specifically, Figures 7A to 7E For example, the figure shows an exposure region SHc located near the outer edge 20e on the upper left side of the wafer 20. Therefore, a portion of the exposure region SH on the upper left side of the wafer 20 extends outside the step 22. This portion extending outside the step 22 constitutes a defective portion of the exposure region SHc. In this case, the imprint process is performed on the exposure region SHc on the inner side of the step 22.

[0094] also, Figures 7A to 7E The right side of the paper surface of the image 83 a captured by the imaging element 83 shown in FIG. 8 coincides with a line (diameter) passing through the center of the wafer 20 .

[0095] like Figure 7A As shown, the control unit 90 of the imprint apparatus 1 specifies the position of the outer edge 20 ei of the wafer 20 and the position of the step 22 i in the shot area SHc based on the image 83 a obtained by capturing the designated shot area SHc.

[0096] Here, in Figure 7F 2 shows an example of the relationship between the step 22 i observed in the image 83 a captured by the imaging element 83 and the step 22 formed on the wafer 20 to be processed by the imprint process.

[0097] As described above, when a step 22 having an inclined shape is observed by the imaging element 83 above the wafer 20, the rounded portion of the step 22, that is, the curved portion with the highest curvature, may be observed as a white line with a certain width, that is, the step 22i when observed by the imaging element 83.

[0098] Furthermore, the above-described relationship also applies to the outer edge portion 20e of the wafer 20 described below. Specifically, when the outer edge portion 20e of the wafer 20 including the curved bevel portion is observed by the imaging element 83 above the wafer 20, the curved portion of the bevel portion may be observed as a white line of a certain width, i.e., the outer edge portion 20e of the wafer 20 as observed by the imaging element 83.

[0099] Hereinafter, when there is no need to distinguish between the step 22i observed by the imaging element 83 and the step 22 actually formed on the wafer 20, it may be simply recorded as the step 22. In addition, when there is no need to distinguish between the outer edge 20ei of the wafer 20 observed by the imaging element 83 and the actual outer edge 20e of the wafer 20, it may be simply recorded as the outer edge 20e. However, it should be noted that Figures 7A to 7E The description is in principle about the level difference 22i and the outer edge portion 20ei observed as the above-mentioned line through the image 83a.

[0100] like Figure 7A As shown, in the image 83a obtained by capturing the exposure area SHc arranged near the outer edge 20e on the upper left of the paper surface of the wafer 20, for example, the outer edge 20ei on the upper left of the paper surface of the wafer 20 and the step 22i are observed.

[0101] like Figure 7B As shown, the control unit 90 reads a droplet recipe from, for example, a storage device and applies it to the exposure area SHc. In the droplet recipe, for example, a plurality of droplets 110d are arranged in a zigzag pattern and distributed at a substantially uniform density throughout the entire exposure area SHe, which has no defects. This allows the droplets 110d to be arranged at a high density, and the droplets 110d actually deposited on the wafer 20 can be arranged with a substantially uniform density within the specified deviation range.

[0102] However, when the object of the imprint process is the shot region SHc having a defect, if the droplet recipe based on the shot region SHe is directly applied, some droplets 110 d will drip outside the step 22 or the outer edge 20 e of the wafer 20 .

[0103] like Figure 7C As shown, the control unit 90 deletes the droplet 110d that would be dropped outside the outer edge 20ei of the wafer 20 from the droplet recipe. At this time, the droplet 110d to be deleted is determined based on information on the outer edge 20ei obtained from the image 83a captured by the imaging element 83.

[0104] In addition, in the actual droplet recipe, the coordinates of the center point of the droplet 110d when viewed from the upper surface of the wafer 20 are set as the dropping position of the droplet 110d. Figure 7B The center point of the droplet 110 d extends outside the outer edge 20 ei of the wafer 20 .

[0105] As mentioned above, the area outside the step 22 is not an area where the imprint process is performed. Furthermore, if the droplet 110d is dropped very close to the step 22, even if it is inside the step 22, it is thought that when it is pressed against the template 10 and spreads, it will overflow outside the step 22. Therefore, the control unit 90 makes corrections so that the dropping position of the droplet 110d is shifted from these areas to an area further inside the wafer 20.

[0106] More specifically, the control unit 90 sets, for example, a region A1 between the outer edge 20ei of the wafer 20 and the step 22i, based on the position of the outer edge 20ei and the position of the step 22i identified from the image 83a as described above. Region A1 is also determined based on information about the step 22i and the outer edge 20ei obtained from the image 83a captured by the imaging element 83. This also applies to regions A2 and A3, described below.

[0107] The distance between the outer edge 20ei of the wafer 20 and the step 22i is specified as distance D1. Furthermore, distance D1 between the outer edge 20ei of the wafer 20 and the step 22i is the distance along a line (diameter) passing through the center of the wafer 20. This also applies to distances D2 and D3 described below.

[0108] The control unit 90 sets a position L1 that is a specified distance D2 inward from the position of the step 22i identified in the above manner, and sets an area A2 between the step 22i and the position L1. Furthermore, the control unit 90 sets a position L2 that is a specified distance D3 inward from the set position L1, and sets an area A3 between the positions L1 and L2.

[0109] like Figure 7DAs shown, the control unit 90 modifies the droplet recipe so that the droplet 110d that would otherwise be placed in areas A1 and A2 is displaced to area A3. The droplet 110d whose center coordinates, when viewed from the top surface of the wafer 20, extend beyond the step 22i is also displaced.

[0110] Here, the radius of the droplet 110d that is crushed when pressed against the template 10 can be calculated using the following formula (1).

[0111] R=sqrt(V / π / RLT)···(1)

[0112] R: Radius of the droplet after imprinting the template

[0113] V: volume of the droplet

[0114] RLT (Residual Layer Thickness): Residual film thickness of the resist

[0115] In addition, in order to suppress the flattened droplet 110d from overflowing to the outside of the step 22, the area A2 is set to satisfy the following formula (2), so that the width of the area A2, that is, the distance D2 between the step 22i and the position L1, is greater than the radius of the flattened droplet 110d.

[0116] D2>R···(2)

[0117] In addition, if the droplet 110d is simply excluded from the areas A1 and A2, the resist material for imprinting the exposure area SHc inside the step 22 will be insufficient. In this case, the resist material becomes insufficient in the area closer to the step 22, and the resist layer 110s formed inside the step 22 cannot be formed (see FIG. Figure 4C ) reaches a position very close to step difference 22.

[0118] Therefore, as described above, the droplets 110d in regions A1 and A2 are moved to region A3 to compensate for the lack of resist. At this time, if region A3 is too large compared to regions A1 and A2, it will be difficult to eliminate the lack of resist near step 22. Therefore, it is preferable to set region A3 so that the widths of each of regions A1 to A3, i.e., the distance D1 between the outer edge 20ei of the wafer 20 and the step 22i, the distance D2 between the step 22i and position L1, and the distance D3 between position L1 and position L2, satisfy the following formula (3).

[0119] D1+D2≧D3···(3)

[0120] This allows the area of ​​region A3 to be smaller than the total area of ​​region A1 and region A2 , suppressing the shortage of resist material near the step 22 , and allowing the resist layer 110 s to reach a position very close to the step 22 .

[0121] like Figure 7E As shown in FIG, the correction recipe is generated by the correction described above. By shifting the droplet 110d dropping position in regions A1 and A2 to region A3, the arrangement density of the droplets 110d in region A3 is higher than that in the region inside region A3 in the correction recipe.

[0122] The droplet 110d in areas A1 and A2 is preferably displaced to the coordinates of the gap between the droplets 110d originally placed in area A3. The droplet 110d in areas A1 and A2 may be displaced by approximately the same distance, or by different distances for each droplet 110d.

[0123] During the imprint process on the shot region SHc having the defect, the control unit 90 of the imprint apparatus 1 generates a correction recipe based on the previously stored droplet recipe as described above, and performs the imprint process on the shot region SHc according to the generated correction recipe.

[0124] (Imprinting method)

[0125] Next, use Figure 8 , the imprinting method of the implementation method is described. Figure 8 1 is a flowchart showing an example of a procedure for an imprint process performed by the imprint apparatus 1 according to the embodiment. Furthermore, when starting the imprint process on the wafer 20, the control unit 90 of the imprint apparatus 1 pre-acquires exposure map information of the wafer 20, for example, from a design device that designs a design map of the wafer 20.

[0126] like Figure 8 As shown, the template 10 and the wafer 20 are loaded into the imprint apparatus 1 (step S101). The control unit 90 refers to, for example, exposure map information of the wafer 20 and determines whether the shot region SH to be processed is a shot region SHc having a defect (step S102).

[0127] When the imprint processing object is the exposure area SHc (step S102: yes), the control unit 90 captures an image of the exposure area SHc through the imaging element 83, for example, and identifies the position of the outer edge portion 20ei and the step difference 22i of the wafer 20 in the exposure area SHc based on the captured image (step S103).

[0128] Furthermore, the control unit 90 calculates correction values ​​for the droplet placement positions of some droplets 110d in the droplet recipe based on the identified positions of the outer edge 20ei and the step 22i of the wafer 20 (step S104). Furthermore, the control unit 90 generates a correction recipe that corrects the droplet placement positions of these droplets 110d (step S105).

[0129] That is, the processing of steps S103 to S105 is equivalent to the above Figures 7A to 7F The steps shown.

[0130] When the imprint processing target is the shot region SHe having no defect (step S102 : No), the processing of steps S103 to S105 is skipped.

[0131] The control unit 90 performs imprint processing on the exposure area SH of the processing object based on a pre-set droplet recipe when the object of imprint processing is the exposure area SHe, or based on a corrected droplet recipe when the object of imprint processing is the exposure area SHc (step S106).

[0132] That is, the processing of step S106 is equivalent to the above Figures 4A to 5B The steps shown.

[0133] When the imprint process for the shot region SH is completed, the control unit 90 refers to, for example, exposure map information of the wafer 20 and determines whether the imprint process for all shot regions SH provided on the wafer 20 is completed (step S107 ).

[0134] If there are unprocessed shot regions SH (step S107 : No), the control unit 90 repeats the process from step S102 , and when the process of all shot regions SH is completed (step S107 : Yes), the control unit 90 unloads the template 10 and the wafer 20 from the imprint apparatus 1 (step S108 ).

[0135] Through the above operations, the imprint process performed by the imprint apparatus 1 according to the embodiment is completed.

[0136] (Summary)

[0137] Sometimes, an imprinting device is used to perform an imprinting process in the manufacturing process of a semiconductor device. Some of the multiple exposure areas set in the wafer are defective exposure areas arranged on the periphery of the wafer. Various problems may occur during the imprinting process of the defective exposure area. Figures 9A to 9F Explain several issues.

[0138] Figures 9A to 9F It is a cross-sectional view illustrating the steps of an imprint process performed by an imprint apparatus of a comparative example.

[0139] Figures 9A to 9C This shows an example of applying a normal droplet formulation to a defective exposure area for imprint processing. Figure 9A As shown, in the imprint process of the comparative example, by applying a conventional droplet recipe, the droplet 110dx is also dropped onto the area near the step difference including the step difference. Figure 9BAs shown, when the template 10x is pressed against these droplets 110dx, as shown in the oval circle, the excess resist material overflows from the step difference to form a resist layer 110sx extending outside the step difference. Figure 9C As shown, when the template 10x is released after the resist pattern 110px is formed by curing the resist, the resist material 110a may adhere to the step of the wafer 20x or the template 110x. This resist material 110a may become a cause of particles in the future.

[0140] Figures 9D to 9F This shows an example of imprinting the defective exposure area using a droplet formulation that excludes droplets that would drip outside the step. Figure 9D As shown in FIG. 1 , in the imprint process of the comparative example, the number of droplets 110dx is reduced, for example, near the step. Figure 9E As shown, when the template 10x is pressed against these droplets 110dx and made to slide for precise alignment, the shear force generated by the sliding of the template 10x increases near the step where the resist material is insufficient. As a result, the sliding of the template 10x is restricted, making it difficult to align the wafer 20x and the template 10x with high precision. Figure 9F As shown in FIG. 1 , the above result shows that the resist pattern 110px formed on the wafer 20x may be positionally shifted.

[0141] In this way, during the imprint process for the defective exposure area, if an excessive amount of resist material is added near the step, this resist material may adhere to the wafer 20x or the template 10x, generating particles. On the other hand, if the amount of resist material added near the step is reduced, the resist material near the step will be insufficient, and the resist pattern 110px may be easily misaligned.

[0142] As described above, the step around the periphery of the wafer 20x may be off-center relative to the overall exposure regions, and the shapes and areas of the defective exposure regions on each wafer 20 may also vary. This can exacerbate the various defects described above caused by the defective exposure regions.

[0143] According to the method for generating a droplet formula of the embodiment, for an exposure area SHc including a step difference 22 among a plurality of exposure areas SH provided on a wafer 20, a droplet formula in which the dropping positions of a plurality of droplets 110d onto the wafer 20 are set to a uniform density is changed so that droplets 110d do not exist in areas A1 and A2 specified by information obtained from the captured image, and the density of droplets 110d near the inner side of a position L1 further inner than the step difference 22i is higher than the density of droplets 110d located inside the position L1 except near the above-mentioned inner side.

[0144] In this manner, the droplets 110d are not dropped onto the area A1 outside the step 22i where imprint processing is not performed, nor are they dropped onto the area A2 located a certain distance D1 inward from the step 22i. This prevents the droplets 110d in the area A2 from overflowing outside the step 22i when they are crushed by the template 10. This prevents the occurrence of defects in the exposure area SHc, such as the resist material 110a adhering to the template 10 or the wafer 20 and becoming a source of particles.

[0145] Furthermore, not only is the droplet 10d not dripped into the areas A1 and A2, but the density of the droplets 110d near the inner side of the position L1 is increased, thereby suppressing the shortage of the resist material near the step 22. Therefore, the accuracy of the fine alignment performed by sliding the template 10 can be improved, and the positional deviation of the resist pattern 110p can be suppressed.

[0146] According to the method for generating a droplet recipe of the embodiment, when changing the droplet recipe, the position of the step 22 i in the exposure area SHc and the position of the outer edge 20 ei of the wafer 20 are specified.

[0147] In this manner, in the imprint process, by specifying the position of the step 22i in each shot area SHc and the outer edge 20ei of the wafer 20 based on the captured image, the droplet 110d can be appropriately dropped in accordance with each shot area SHc.

[0148] According to the method for generating a droplet recipe of the embodiment, changing the droplet recipe includes shifting the dropping position of the droplet 110 d located in the areas A1 and A2 in the droplet recipe before the change to the area A3 .

[0149] In this manner, the droplets 10d in the areas A1 and A2 are not simply removed but are displaced to the area A3 inside these areas A1 and A2, thereby suppressing the shortage of resist material near the step 22. Therefore, the accuracy of fine alignment by sliding the template 10 can be improved, and positional deviation of the resist pattern 110p can be suppressed.

[0150] According to the droplet recipe generation method of the embodiment, area A2 is set so that distance D2 is greater than the radius of each of the droplets 110d after the imprint template 10 is pressed against the droplets 110d. This more reliably prevents the droplets 110d from overflowing outside the step 22 when flattened by the template 10.

[0151] According to the droplet recipe generation method of the embodiment, regions A2 and A3 are set so that the sum of distance D1 and distance D2 between step 22i, defined by the captured image information, and outer edge 20ei of wafer 20 is greater than distance D3. In this way, by adding droplets 110d from regions A1 and A2 to region A3, which is smaller than the combined area of ​​regions A1 and A2, it is possible to further suppress resist material shortages near step 22.

[0152] According to the droplet recipe generation method of the embodiment, the step 22 surrounds the outer periphery of the wafer 20, and the distance D3 varies in the two or more exposure areas SHc that include the step 22. In other words, the wafer 20 has a convex region 21 with a central portion protruding from the step 22, and the convex region 21 is eccentric relative to the wafer 20 when viewed from the top surface of the wafer 20. As described above, even for the eccentric wafer 20, a correction recipe is generated corresponding to each exposure area SHc, allowing droplets 110d to be appropriately deposited.

[0153] According to the semiconductor device manufacturing method of the embodiment, the photoresist layer 100 used to form the step 22 is removed by irradiating the outer periphery of the wafer 20 with exposure light while rotating the wafer 20, thereby exposing and developing a predetermined width of the photoresist layer 100 on the outer periphery of the wafer 20. Alternatively, the photoresist layer 100 can be removed by spraying a photoresist layer 100 removal liquid onto the outer periphery of the wafer 20 while rotating the wafer 20, thereby dissolving the photoresist layer 100 on the outer periphery of the wafer 20 by a predetermined width.

[0154] The edge bead removal process performed in this manner may cause eccentricity as described above, and the shape and area of ​​the exposure area SHc may vary from wafer to wafer 20 and from exposure area to exposure area SHc. However, as described above, a correction recipe is generated for each exposure area SHc, allowing the droplet 110d to be appropriately deposited.

[0155] While several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments may be implemented in various other forms and may be omitted, replaced, or modified without departing from the spirit of the invention. These embodiments and their variations are intended to be within the scope and spirit of the invention and are encompassed by the invention set forth in the claims and their equivalents.

[0156] Explanation of symbols

[0157] 1: Imprinting device

[0158] 10: Template

[0159] 10p,40p:Pattern

[0160] 20: Wafer

[0161] 20e: outer edge

[0162] 21: Convex area

[0163] 22: Step Difference

[0164] 23: Marginal Area

[0165] 30: Multiple layers

[0166] 40: Processed layer

[0167] 50: SOC layer

[0168] 60:SOG layer

[0169] 83,84: Camera components

[0170] 90: Control Department

[0171] 110d: Droplets

[0172] 110p: resist pattern

[0173] 110s: Anti-corrosion layer

[0174] A1, A2, A3: Area

[0175] D1, D2, D3: distance

[0176] L1, L2: Location

[0177] SH, SHc, SHe: exposure area.

Claims

1. A method for producing a droplet recipe for imprint processing of a substrate having a step difference at its periphery, and Acquiring first information and second information, wherein the first information indicates the position of the step in a first emission region including the step among a plurality of emission regions provided on the substrate, and the second information indicates the position of an outer edge portion of the substrate, Based on the acquired first information and second information, third information is set, wherein the third information indicates a first region between the step and an outer edge of the substrate; Based on the first information, fourth information is set, wherein the fourth information indicates a second region between a first position that is a first distance from the step toward the inner side of the substrate and the step; The droplet formulation before the change in which the dropping positions of the plurality of droplets onto the substrate are set to a uniform density is changed so that no droplets exist in the first area and the second area specified by the third information and the fourth information, and the density of the droplets located near the inner side of the first position is higher than the density of the droplets located inside the first position except near the inner side.

2. The method for producing a droplet formulation according to claim 1, wherein The changes include: fifth information is set, wherein the fifth information indicates a third region between the first position and a second position that is a second distance from the first position to the inner side of the substrate; The dropping positions of the droplets located in the first and second regions in the droplet recipe before the change are shifted to the third region.

3. The method for producing a droplet formulation according to claim 1, wherein The fourth information is: The first distance is set to be greater than the radius of the plurality of droplets after the template is pressed against the plurality of droplets.

4. The method for producing a droplet formulation according to claim 2, wherein The fourth information and the fifth information are: The distance is set such that the total of the first distance and a third distance between the step defined by the first information and the second information and the outer edge of the substrate is equal to or greater than the second distance.

5. The method for producing a droplet formulation according to claim 1, wherein In the droplet formulation before the change, The dropping positions are specified so that the plurality of droplets are dropped at a predetermined period.

6. The method for producing a droplet formulation according to claim 4, wherein The step surrounds the outer periphery of the substrate, Among the plurality of emission regions, two or more emission regions including the step difference are provided on the substrate. The third distance is different in two or more emission areas including the step difference.

7. The method for producing a droplet formulation according to claim 6, wherein The substrate has a convex region with the step as a boundary and a central portion protruding, When viewed from the upper surface of the substrate, the center of the convex region is offset relative to the substrate.

8. The method for producing a droplet formulation according to claim 1, wherein The droplet formula before the change is: A second emission region, the entire region of which is located on the inner side of the step, among the plurality of emission regions is set as a reference, and The dropping positions of the plurality of droplets are set to have a uniform density over the entire second emission region.

9. The method for generating a droplet formulation according to claim 8, further comprising: With respect to the droplet formulation before the change, droplets located outside the outer edge are deleted.

10. The method for producing a droplet formulation according to claim 1, wherein The first information and the second information are acquired through images captured by an imaging element.

11. An imprint method, wherein an imprint apparatus is used to perform an imprint method on a substrate having a step difference at its outer periphery, wherein a processor of the imprint apparatus is: obtaining first information and second information, wherein the first information indicates the position of the step in a first emission region including the step among a plurality of emission regions provided on the substrate, and the second information indicates the position of an outer edge portion of the substrate; Based on the acquired first information and second information, third information is set, wherein the third information indicates a first region between the step and an outer edge of the substrate; Based on the first information, fourth information is set, wherein the fourth information indicates a second region between a first position that is a first distance from the step toward the inner side of the substrate and the step; The droplet recipe before the change, in which the droplet dropping positions onto the substrate are set to have a uniform density, is changed so that no droplets exist in the first area and the second area defined by the third information and the fourth information, and the density of the droplets located near the inner side of the first position is higher than the density of the droplets located inside the first position except near the inner side. In the first ejection region, the liquid dropping device of the imprint device is controlled so as to drop the plurality of droplets in the first ejection region using the changed liquid droplet recipe.

12. A method for manufacturing a semiconductor device, comprising: An imprint apparatus performs an imprint process on a substrate having a step difference at its outer periphery, and includes: forming a processed layer on the substrate; performing the imprint process on each of a plurality of emission regions provided on the substrate to form a mask pattern above the processed layer; and Processing the processed layer using the mask pattern; and The processor of the imprinting device is: Acquiring first information and second information, wherein the first information indicates the position of the step in a first emission region including the step among a plurality of emission regions provided on the substrate, and the second information indicates the position of an outer edge portion of the substrate, Based on the acquired first information and second information, third information is set, wherein the third information indicates a first region between the step and an outer edge of the substrate; Based on the first information, fourth information is set, wherein the fourth information indicates a second region between a first position that is a first distance from the step toward the inner side of the substrate and the step; The droplet recipe before the change, in which the droplet dropping positions onto the substrate are set to have a uniform density, is changed so that no droplets exist in the first area and the second area specified by the third information and the fourth information, and the density of the droplets located near the inner side of the first position is higher than the density of the droplets located inside the first position except near the inner side. In the first ejection region, the liquid dropping device of the imprint device is controlled so as to drop the plurality of droplets in the first ejection region using the changed liquid droplet recipe.

13. The method for manufacturing a semiconductor device according to claim 12, wherein The step difference is formed by: forming a photoresist layer covering the entire surface of the substrate, removing the photoresist layer by a predetermined width while rotating the substrate; The surface layer of the substrate is removed at the outer periphery of the substrate exposed with the predetermined width due to the removal of the photoresist layer.

14. The method for manufacturing a semiconductor device according to claim 13, wherein The removal of the photoresist layer is carried out in the following manner: The photoresist layer at the periphery of the substrate is exposed to light with a predetermined width and developed.

15. The method for manufacturing a semiconductor device according to claim 13, wherein The removal of the photoresist layer is carried out in the following manner: The photoresist layer removal liquid is sprayed toward the outer periphery of the substrate to dissolve the photoresist layer at the outer periphery of the substrate by a predetermined width.

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