Pattern formation method, semiconductor device manufacturing method, and imprint apparatus

Abstract

To improve overlaying accuracy of a pattern on a substrate.SOLUTION: A pattern formation method holds a substrate having a plurality of shot regions on a suction chuck having a first suction region for sucking the outer edge part of the substrate and a second suction region for sucking the inside region of the outer edge part, wherein the plurality of shot regions are arranged astride the outer edge part and the inside region, has a first alignment mark in the inside region, has a second alignment mark on the outer edge part, and includes a first shot region which is partially chipped on the outer edge part side, the first and third alignment marks are aligned in a state in which a template is pushed against a resin film, suction force in the first suction region is adjusted while observing the second and fourth alignment marks through the template, a warpage amount of the outer edge part is changed, and the second and fourth alignment marks are aligned.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] Embodiments of the present invention relate to a pattern forming method, a method for manufacturing a semiconductor device, and an imprint apparatus.

Background Art

[0002] In the manufacturing process of a semiconductor device, an imprint process may be included. In the imprint process, for example, a substrate is adsorbed onto a suction chuck, and a template is pressed against a resin film formed on the substrate to transfer the pattern of the template.

[0003] When transferring a pattern as described above, alignment marks formed on both the substrate and the template are used to align the transfer position of the pattern with respect to the substrate. However, if the substrate warps due to adsorption onto the suction chuck, the transfer position of the pattern may shift.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] One embodiment aims to provide a pattern forming method, a method for manufacturing a semiconductor device, and an imprint apparatus that can improve the accuracy of pattern overlay on a substrate.

Means for Solving the Problems

[0006] The pattern forming method of the embodiment involves holding a substrate having a plurality of shot regions on a suction chuck having a first suction region for suctioning the outer edge of the substrate and a second suction region for suctioning the inner region of the outer edge; forming a resin film on at least one of the plurality of shot regions; and pressing a template pattern onto the resin film on the one shot region to transfer the pattern to the resin film, wherein the plurality of shot regions are arranged across the outer edge and the inner region, have a first alignment mark in the inner region, and have a second alignment mark in the outer edge. The template has alignment marks and includes a first shot region which is partially missing on the outer edge side, and the template has a third alignment mark used for alignment with the first alignment mark and a fourth alignment mark used for alignment with the second alignment mark, and when transferring the pattern to the resin film on the first shot region, the first and third alignment marks are aligned while the template is pressed against the resin film, and the second and fourth alignment marks are observed through the template. 、 In the first suction region pressure Power By creating a negative pressure relative to the reference pressure and making the pressure in the second suction region a positive pressure relative to the reference pressure, the back surface of the substrate in the inner region is pressurized. The outer edge portion and the inner region The amount of curvature is changed to align the second and fourth alignment marks. [Brief explanation of the drawing]

[0007] [Figure 1] A schematic diagram showing an example of the configuration of an imprint device according to an embodiment. [Figure 2] A schematic diagram showing an example of the configuration of a wafer chuck in an imprint apparatus according to an embodiment. [Figure 3] A schematic diagram showing an example of the configuration of a template stage included in an imprint device according to an embodiment. [Figure 4] A top view showing an example of the wafer configuration according to the embodiment. [Figure 5] A cross-sectional view illustrating, in sequence, some of the steps in the method for manufacturing a semiconductor device according to an embodiment. [Figure 6] A cross-sectional view illustrating, in sequence, some of the steps in the method for manufacturing a semiconductor device according to an embodiment. [Figure 7] A diagram showing an example of the alignment operation performed by the imprint device according to the embodiment. [Figure 8] A schematic diagram showing the relationship between the relative positions of alignment marks on the template and wafer in the comparative example and the amount of wafer warpage. [Figure 9] A diagram showing an example of the alignment operation performed by an imprinting device according to a modified embodiment. [Figure 10] A top view showing an example of the configuration of moiré-type alignment marks provided on a template and wafer according to another modification of the embodiment. [Modes for carrying out the invention]

[0008] Embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the embodiments described below. Furthermore, the components in the embodiments described below include those that are easily conceivable by those skilled in the art or that are substantially identical.

[0009] (Example of an imprint device configuration) Figure 1 is a schematic diagram showing an example of the configuration of the imprint apparatus 1 according to the embodiment. Figure 1(a) is an overall view of the imprint apparatus 1, and Figure 1(b) is an enlarged view of the detection system 86a showing the detailed configuration of the image sensors 84 (84a to 84d) provided in the imprint apparatus 1.

[0010] As shown in Figure 1, the imprint apparatus 1 comprises a template stage 81, a wafer stage 82, image sensors 83, 84a to 84d, a reference mark 85, an alignment unit 86, a liquid droplet dispenser 87, a stage base 88, a light source 89, a control unit 90, and a storage unit 91. The imprint apparatus 1 has a template 10 installed for transferring a pattern onto the resist on the wafer 20.

[0011] The wafer stage 82 includes a wafer chuck 82b and a main body 82a. The wafer chuck 82b includes a plurality of suction channels 820 that suck the back surface of the wafer 20, and fixes the wafer 20 at a predetermined position on the main body 82a. The plurality of suction channels 820 are respectively connected to a pump (not shown).

[0012] A reference mark 85 is provided on the wafer stage 82. The reference mark 85 is used for alignment when loading the wafer 20 onto the wafer stage 82.

[0013] The wafer stage 82 places the wafer 20 and moves within a plane (horizontal plane) parallel to the placed wafer 20. When dropping resist onto the wafer 20, the wafer stage 82 moves the wafer 20 to the lower side of the droplet dropping device 87, and when performing a transfer process onto the wafer 20, the wafer stage 82 moves the wafer 20 to the lower side of the template 10.

[0014] The stage base 88 supports the template 10 by the template stage 81 and presses the pattern of the template 10 against the resist on the wafer 20 by moving in the vertical direction (vertical direction).

[0015] An alignment unit 86 including a plurality of image sensors 83 is provided on the stage base 88. The alignment unit 86 performs position detection of the wafer 20 and position detection of the template 10 based on alignment marks provided on the wafer 20 and the template 10 respectively.

[0016] The alignment unit 86 includes a detection system 86a and an illumination system 86b. The illumination system 86b irradiates light onto the wafer 20 and the template 10 to make the alignment marks formed thereon visible. The detection system 86a detects an image of the alignment marks and aligns their positions to perform alignment between the wafer 20 and the template 10.

[0017] The detection system 86a and the illumination system 86b each include mirrors 86x and 86y, such as dichroic mirrors, as imaging units. The mirrors 86x and 86y form images from the wafer 20, such as alignment marks, and the template 10 using light from the illumination system 86b.

[0018] Specifically, the light Lb from the illumination system 86b is reflected by the mirror 86y toward the area below where the wafer 20 and other components are located. The light La from the wafer 20 and other components is reflected toward the detection system 86a by the mirror 86x. In addition, some of the light Lc from the wafer 20 and other components passes through the mirrors 86x and 86y and travels toward the image sensor 83 above.

[0019] The image sensor 83 captures a portion of this light Lc as an image including alignment marks, etc. The image captured by the image sensor 83 is used by the control unit 90 to determine the state of the alignment marks.

[0020] On the other hand, the light La reflected by the mirror 86x toward the detection system 86a proceeds toward the multiple image sensors 84a to 84d provided by the detection system 86a.

[0021] As shown in Figure 1(b), the multiple image sensors 84a to 84d are arranged so that they can each image different points in a single shot area SH on the wafer 20, which is the imprinting area of ​​the template 10.

[0022] The image sensors 84a to 84d capture the light La reflected by the mirror 86x as an image including alignment marks, etc. The image captured by the image sensors 84a to 84d is used by the control unit 90 to align the wafer 20 with the template 10.

[0023] The droplet dispensing device 87 is a device that drops resist onto the wafer 20 using an inkjet method. The inkjet head of the droplet dispensing device 87 has multiple fine holes from which resist droplets are ejected, and the resist droplets are dropped onto a single shot area SH on the wafer 20.

[0024] In this embodiment, the imprint apparatus 1 is configured to drop resist onto the wafer 20, but the resist may be applied to the entire surface of the wafer 20 by a spin coating method.

[0025] The light source 89 is a device that irradiates light, such as ultraviolet light, to cure the resist, and is located above the stage base 88. The light source 89 irradiates light from above the template 10 while the template 10 is pressed against the resist.

[0026] The control unit 90 is configured as a computer, for example, equipped with a hardware processor such as a CPU (Central Processing Unit), memory, and an HDD (Hard Disk Drive). The control unit 90 controls the template stage 81, wafer stage 82, reference marks 85, alignment unit 86 including image sensors 83, 84a to 84d, liquid drop dispenser 87, stage base 88, and light source 89.

[0027] Next, using Figure 2, we will describe a detailed example of the configuration of the wafer chuck 82b provided in the imprint apparatus 1.

[0028] Figure 2 is a schematic diagram showing an example of the configuration of the wafer chuck 82b provided in the imprint apparatus 1 according to the embodiment. Figure 2(a) is a top view of the wafer chuck 82b, and Figure 2(b) is a partially enlarged cross-sectional view of the wafer chuck 82b.

[0029] As shown in Figure 2(a), the wafer chuck 82b, which functions as a suction chuck, is divided into multiple zones Z1 to Z5 by multiple ring-shaped protrusions 821 to 825.

[0030] Multiple ring-shaped protrusions 821-825 are arranged concentrically from the inside to the outside of the wafer chuck 82b in this order. The spacing between these ring-shaped protrusions 821-825 narrows as they move towards the outside of the wafer chuck 82b.

[0031] Zone Z1 is a circular region located further inside the ring-shaped projection 821, which is positioned closest to the center of the wafer chuck 82b. Zone Z1 is provided with multiple pin holes 82p. These pin holes 82p house wafer pins (not shown). The wafer pins protrude from the surface of the wafer chuck 82b to hold the wafer 20 above the wafer chuck 82b when loading or unloading the wafer 20.

[0032] Zone Z2 is an annular region located between ring-shaped protrusions 821 and 822. Zone Z3 is an annular region located between ring-shaped protrusions 822 and 823. Zone Z4 is an annular region located between ring-shaped protrusions 823 and 824. Zone Z5 is an annular region located between ring-shaped protrusions 824 and 825.

[0033] As shown in Figure 2(b), the multiple ring-shaped protrusions 821-825 protrude from the surface of the wafer chuck 82b. Of the multiple ring-shaped protrusions 821-825, the protrusion heights of ring-shaped protrusions 821-824 are equal to each other. The ring-shaped protrusion 825, which is located on the outermost periphery of the wafer chuck 82b, has a lower protrusion height than the other ring-shaped protrusions 821-824.

[0034] Inside the wafer chuck 82b, there are multiple suction passages 820, the downstream side of which is connected to the pump P. These suction passages 820 open into zones Z1 to Z5, which are divided by multiple ring-shaped protrusions 821 to 825.

[0035] The suction passage 820 does not open in the annular region extending beyond the ring-shaped projection 825 located closest to the outermost periphery of the wafer chuck 82b, that is, to the outer edge of the wafer chuck 82b outside of zone 5.

[0036] The wafer 20 is placed on the wafer stage 82 with its back surface supported by at least the upper ends of the ring-shaped protrusions 821 to 824 among the multiple ring-shaped protrusions 821 to 825. As a result, the inner region of the wafer 20 is positioned to overlap with zones Z1 to Z4 of the wafer chuck 82b, and the outer edge of the wafer 20 is positioned to overlap with zone Z5 of the wafer chuck 82b.

[0037] With the wafer 20 supported on the upper ends of the ring-shaped protrusions 821 to 824, the pumps P connected to the multiple suction passages 820 are activated, and the back surface of the wafer 20 is sucked through the multiple openings of the suction passages 820 provided in each zone Z1 to Z5, causing the wafer 20 to be adsorbed onto the upper surface of the wafer chuck 82b.

[0038] In this case, the suction force can be adjusted for each zone Z1 to Z5 by controlling the operating state of the pump P. Furthermore, it is possible not only to create negative pressure by suctioning the back surface of the wafer 20, but also to create positive pressure on the back surface of the wafer 20. In addition, valves or the like may be provided in each of the multiple suction passages 820, and the suction force for each zone Z1 to Z5 can be adjusted by opening and closing these valves. This makes it possible to reduce the number of pumps P connected to the suction passages 820, for example.

[0039] Next, using Figure 3, we will describe a detailed configuration example of the template stage 81 and the template 10 held in the template stage 81 of the imprint device 1.

[0040] Figure 3 is a schematic diagram showing an example of the configuration of the template stage 81 included in the imprint apparatus 1 according to the embodiment. Figure 3(a) is a cross-sectional view of the template stage 81, and Figure 3(b) is a top view of the pattern PT of the template 10 held by the template stage 81.

[0041] As shown in Figure 3(a), the template stage 81 comprises a main body 811, a template chuck 812, a pressurizing unit 813, and a drive unit 814.

[0042] The main body 811 of the template stage 81 is a flat plate-shaped member, and the template 10 is held on its lower surface by a template chuck 812. The template chuck 812 is provided on the lower surface of the main body 811 and holds the template 10 above the wafer 20 with the pattern 10p facing downwards by vacuum suction using a suction mechanism (not shown).

[0043] The pressurized section 813 comprises a pressurized chamber 813r, which is the space between the main body 811 of the template stage 81 and the template 10; a through hole 813h provided in the main body 811 and communicating with the pressurized chamber 813r; and a tube 813t connected to the through hole 318h.

[0044] The pressurizing section 813 allows air or the like to flow from the tube 813t through the through-hole 813h into the pressurizing chamber 813r, thereby pressurizing the back surface of the template 10 with air pressure or the like. When pressing the template 10 against the resist on the wafer 20, the pressurizing section 813 pressurizes the back surface of the template 10, causing the central part of the pattern 10p on the template 10 to bend toward the wafer 20.

[0045] The drive unit 814 holds the template 10 and moves the template stage 81 up and down using a motor (not shown). At this time, by adjusting the driving force of the motor of the drive unit 814, the lifting speed of the template stage 81, the tilt of the template 10 relative to the wafer 20, and the force with which the pattern 10p of the template 10 is pressed against the resist on the wafer 20 can be controlled.

[0046] More specifically, the drive unit 814 can apply force individually to each of the four corners of the rectangular template 10. Therefore, the drive unit 814 can adjust the tilt of the template 10 by applying different forces to each of its four corners. Furthermore, the drive unit 814 can adjust the force with which the template 10 is pressed against the resist by changing the strength of the force applied to each of its four corners. Hereafter, the force with which the template 10 is pressed against the resist will also be referred to as the imprinting force of the template 10.

[0047] Furthermore, while holding the template 10, the drive unit 814 moves the template stage 81 in a direction along the planes of the template 10 and the wafer 20, that is, horizontally, using a motor or the like (not shown). This adjusts the horizontal relative position of the template 10 and the wafer 20.

[0048] The template 10 is a substantially flat quartz material or the like, and when held on the template stage 81, it comprises a mesa portion 10m protruding from the lower surface and a pattern 10p formed on the surface of the mesa portion 10m. The pattern 10p is a pattern having any shape, such as a line and space pattern, a dot pattern, or a hole pattern, and is transferred to the resist on the wafer 20. The area on the wafer 20 to which the pattern 10p has been transferred becomes the element area of ​​the semiconductor device.

[0049] Multiple alignment marks 10a are provided around the pattern 10p of the template 10. Each alignment mark 10a has a concave shape, for example, recessed from the contact surface with the resist when the template 10 is pressed against the resist on the wafer 20.

[0050] (Method of manufacturing semiconductor devices) Next, the manufacturing method of the semiconductor device according to the embodiment will be described using Figures 4 to 6. The manufacturing process of the semiconductor device according to the embodiment includes an imprint process by the imprint apparatus 1 described above.

[0051] First, Figure 4 shows an example of a wafer 20 to be processed by the imprint apparatus 1. Figure 4 is a schematic diagram showing an example of the configuration of the wafer 20 according to the embodiment. Figure 4(a) is a top view of the wafer 20, and Figure 4(b) is an enlarged top view of one shot region SH.

[0052] As shown in Figure 4(a), the upper surface of the wafer 20, which serves as the substrate, is divided into multiple shot regions SH. Each of the multiple shot regions SH has, for example, a rectangular shape and is arranged in a matrix across the entire surface of the wafer 20. These shot regions SH are areas that constitute a single processing unit in several of the manufacturing processes of the semiconductor device, including the imprint process.

[0053] In other words, for example, in the imprint process described later, one shot area SH corresponds to the area on which the pattern 10p of the template 10 is transferred in one imprint process. Therefore, one shot area SH may have an area and shape that is approximately equal to the area and shape of the upper surface of the mesa portion 10m of the template 10 described above.

[0054] However, multiple shot regions SH include a missing shot region SHc located at the edge of the outer periphery of the wafer 20. Because the missing shot region SHc is located at the edge of the outer periphery of the wafer 20, it is partially missing and lacks some of the predetermined components that the shot region SH should have in terms of design.

[0055] In other words, the defective shot region SHc has a predetermined area that is less than the area that a normal shot region SH should have. The area and shape of the defective shot region SHc can vary depending on the outer peripheral position of the wafer 20 where the defective shot region SHc is located.

[0056] Figure 4(b) shows a shot region SH without defects. As shown in Figure 4(b), each shot region SH has a transfer region 20t in the center to which the pattern 10p of the template 10 is transferred. After a predetermined process, the transfer region 20t becomes an element region of a semiconductor device. One or more semiconductor devices can be obtained from the element regions.

[0057] Furthermore, depending on the shape and area of ​​the defective shot region (SHc), there may be defective shot regions (SHc) from which one or more semiconductor devices can be obtained, and defective shot regions (SHc) from which no semiconductor devices can be obtained. Normally, imprint processing is not performed on defective shot regions (SHc) from which no semiconductor devices can be obtained.

[0058] Multiple alignment marks 20a are provided around the transfer region 20t. These alignment marks 20a are formed, for example, on the workpiece film 21 formed on the upper surface of the wafer 20, on the underlying film of the workpiece film 21, or on the wafer 20. Each alignment mark 20a is used in conjunction with the corresponding alignment mark 10a of the template 10 described above, and is used to align the wafer 20 with the template 10.

[0059] Figures 5 and 6 are cross-sectional views illustrating, in sequence, a part of the procedure for manufacturing a semiconductor device according to an embodiment. The process shown in Figures 5 and 6 is also a pattern formation method for forming a pattern based on the pattern 10p of the template 10 on a workpiece film 21 formed on a wafer 20.

[0060] In Figures 5 and 6, the processes shown in Figures 5(a) to 6(a) represent an example of the procedure for the imprint method using the imprint apparatus 1. Furthermore, the processes shown in Figures 5(a) to 6(a) are also a pattern formation method for forming the pattern 10p of the template 10 on the resist film 30 formed on the wafer 20. Thus, the imprint process and pattern formation process using the imprint apparatus 1 are performed as one step in the manufacturing process of a semiconductor device.

[0061] As shown in Figure 5(a), a film to be processed, for example, a film to be processed, 21, is formed on the wafer 20. The film to be processed, 21, is, for example, a silicon oxide film, a silicon nitride film, or a metal film, and is a film that is processed into a shape corresponding to the pattern 10p of the template 10.

[0062] Depending on the manufacturing process stages the wafer 20 has gone through so far, one or more underlying films may be formed beneath the film to be processed 21. Alternatively, if the imprint process is performed for the purpose of processing the surface of the wafer 20, the film to be processed 21 may be the surface layer of the wafer 20, such as a silicon wafer.

[0063] As described above, the workpiece film 21, the underlying film, or the wafer 20 has multiple alignment marks 20a formed on it, which are used for alignment with the template 10.

[0064] The wafer 20 is placed on the wafer chuck 82b of the imprint apparatus 1, and the wafer stage 82 is moved below the liquid droplet dispenser 87. The liquid droplet dispenser 87 then uses an inkjet method to drop resist onto the workpiece film 21 of the shot regions SH that are to be imprinted, from among the multiple shot regions SH.

[0065] The resist dropped from the liquid dropping device 87 is an organic material such as a photocurable resist that hardens when irradiated with ultraviolet light or the like. When dropped from the liquid dropping device 87, the resist is in an uncured liquid state.

[0066] As a result, a resist film 30, which is a resin film, is formed on the processed film 21 of one shot region SH.

[0067] Thus, the uncured resist film 30 formed by the inkjet method may be arranged in droplet form in the shot region SH, not limited to the example in Figure 5(a). Alternatively, as described above, the resist film 30 may be formed by applying the resist using a spin coating method or the like. In this case, the resist film 30 is formed substantially uniformly over the entire surface of the wafer 20.

[0068] The wafer stage 82 holding the wafer 20 is moved to position the shot area SH, which will be subjected to imprinting, below the template 10 held on the template stage 81 of the imprinting apparatus 1.

[0069] As shown in Figure 5(b), the template stage 81 is lowered to press the pattern 10p of the template 10 against the resist film 30 on the wafer 20.

[0070] At this time, the drive unit 814 provided on the template stage 81 adjusts the descent speed of the template stage 81, the descent distance, the horizontality of the template 10 relative to the wafer 20, and the printing force of the template 10.

[0071] Furthermore, the drive unit 814 adjusts the lowering position of the template stage 81 so that a predetermined gap is created between the template 10 and the workpiece film 21 on the wafer 20. This prevents the template 10 and the workpiece film 21 from coming into contact.

[0072] Furthermore, when bringing pattern 10p into contact with the resist film 30, the back surface of template 10 is pressurized by the pressurizing section 813 provided on template stage 81, causing the central portion of pattern 10p on template 10 to bend toward wafer 20. This suppresses the trapping of air bubbles in the uneven portions of pattern 10p.

[0073] In this manner, with the pattern 10p in contact with the resist film 30, the image sensor 83 of the imprint apparatus 1 observes the multiple alignment marks 10a provided on the template 10, and maintains the contact between the pattern 10p and the resist film 30 until these alignment marks 10a are filled with the resist film 30. During this time, the resist film 30 also fills the recesses of the pattern 10p on the template 10.

[0074] The alignment marks 10a are filled with the resist film 30, which improves the visibility of the alignment marks 10a and the alignment marks 20a on the wafer 20 when viewed through the template 10. In other words, it becomes easier to observe the alignment marks 10a and 20a using the image sensors 84a to 84d of the imprint apparatus 1.

[0075] Therefore, after filling the resist film 30, the individual alignment marks 10a on the template 10 and the individual alignment marks 20a on the wafer 20 corresponding to these marks are observed by the image sensors 84a to 84d, and the wafer 20 and the template 10 are aligned in the direction along the surface of the wafer 20. At this time, for example, the alignment marks 10a and 20a at the corresponding positions are observed while appropriately switching between the image sensors 84a to 84d being used, and their alignment is performed as appropriate.

[0076] Figures 5(c) to 5(d) are images of alignment marks 10a and 20a captured by any of the image sensors 84a to 84d, showing how the alignment marks 10a and 20a are used to align the wafer 20 with the template 10.

[0077] As shown in Figure 5(c), the alignment mark 20a on the wafer 20 has a rectangular shape composed of, for example, four bars. Similarly, the alignment mark 10a on the template 10 is composed of, for example, four bars, and has a smaller rectangular shape than the alignment mark 20a on the wafer 20.

[0078] Ideally, the relative positions of the wafer 20 and the template 10 are adjusted so that the alignment marks 10a of the template 10 are positioned within the alignment marks 20a of the wafer 20, with their centers aligned, by observing from the image sensor 84a~84d side. This allows for alignment of the wafer 20 and the template 10, and by transferring the pattern 10p of the template 10 to the resist film 30 of the wafer 20 in this state, a pattern can be formed at the desired position on the wafer 20.

[0079] The alignment marks 10a and 20a configured as described above are called bar-in-bar marks, and are used for precise positioning after the template 10 is brought into contact with the resist film 30 on the wafer 20. However, the alignment marks 10a and 20a may be other types of marks, such as box-in-box marks.

[0080] In the example shown in Figure 5(c), alignment marks 10a and 20a are misaligned in both the X-direction along the surface of the wafer 20 and the Y-direction perpendicular to the X-direction along the surface of the wafer 20.

[0081] As shown in Figure 5(d), for example, a drive unit 814 provided on the template stage 81 moves the template 10 in the X direction to align the alignment marks 10a and 20a in the X direction.

[0082] As shown in Figure 5(e), for example, the drive unit 814 moves the template 10 in the Y direction to align the alignment marks 10a and 20a in the Y direction.

[0083] This aligns the wafer 20 and the template 10. However, the alignment operation for aligning the wafer 20 and the template 10 may be more complex than the operation illustrated in Figures 5(c) to 5(e).

[0084] For example, the positions of the alignment marks 10a and 20a in the X and Y directions may be gradually adjusted while making repeated fine adjustments simultaneously. Therefore, the alignment operation of the imprint apparatus 1 may be an operation in which the template 10 is slid across the resist film 30 on the wafer 20, for example, in a circular motion, to perform the alignment.

[0085] Furthermore, in the example described above, the template 10 is moved relative to the wafer 20 to perform alignment, but for example, the wafer 20 may be moved relative to the template 10 using a wafer stage 82 to perform alignment.

[0086] Furthermore, the example shown in Figure 5(e) represents a case where the alignment of the wafer 20 and the template 10 is ideal, that is, where there is no misalignment between the wafer 20 and the template 10. In practice, however, the alignment operation may be terminated while allowing a misalignment amount of less than a predetermined amount.

[0087] In this case, for example, the period for performing the alignment operation may be set in advance, and the alignment operation may be terminated when the predetermined time has been reached. Alternatively, upper limits may be set in advance for the amount of misalignment in the X and Y directions of the alignment marks 10a and 20a, and the alignment operation may be terminated when the amount of misalignment falls below the upper limit.

[0088] Alternatively, both the alignment operation period and the alignment error threshold can be defined, and the alignment operation can be terminated when the alignment error falls below the threshold or when the alignment operation period expires and a timeout occurs.

[0089] After the alignment of the wafer 20 and the template 10 is complete, ultraviolet light is irradiated onto the resist film 30 via the template 10 while maintaining the position of the wafer 20 and the template 10. As a result, the resist film 30 hardens while filling the recesses of pattern "0p".

[0090] As shown in Figure 6(a), the template 10 is raised by the drive unit 814 provided on the template stage 81. At this time, since the wafer 20 is held in place by the wafer chuck 82b, the template 10 can be released from the wafer 20 without the wafer 20 detaching from the wafer stage 82.

[0091] This creates a resist pattern 30p onto which the pattern 10p of the template 10 has been transferred. A thin film called the resist residue 30r is formed at the bottom of the pattern of the resist pattern 30p. As mentioned above, this is because the template 10 was pressed against the wafer 20 with a gap between them in order to suppress contact between the template 10 and the wafer 20.

[0092] With the above steps, the imprinting process by the imprinting device 1 of this embodiment is completed.

[0093] As shown in Figure 6(b), the entire surface of the resist pattern 30p is treated by processing, for example, using oxygen plasma, to remove the residual resist film 30r at the bottom of the pattern. This exposes the surface of the processed film 21 at the bottom of the pattern.

[0094] As shown in Figure 6(c), by etching the workpiece film 21 via the resist pattern 30p, a workpiece film pattern 21p is formed in which the resist pattern 30p is transferred to the workpiece film 21.

[0095] Subsequently, by embedding a metal film, such as tungsten or copper, into the processed film pattern 21p, a desired structure that will become part of a semiconductor device can be obtained.

[0096] For example, if pattern 10p of template 10 is a line-and-space pattern, then the pattern 21p of the film to be processed will also have a line-and-space pattern. By embedding a metal film here, wiring for semiconductor devices can be obtained.

[0097] Furthermore, if pattern 10p of template 10 is a dot pattern, the workpiece film pattern 21p will have a hole pattern which is an inverted dot pattern. By embedding a metal film here, contacts or vias for semiconductor devices can be obtained.

[0098] From this point onward, the semiconductor device according to the embodiment is manufactured by repeatedly forming various films on the wafer 20 and applying desired processing to these films.

[0099] As described above, in the imprint apparatus 1 of the embodiment, alignment marks 10a and 20a are used between the template 10 and the wafer 20 to align the template 10 and the wafer 20 in the X and Y directions. This improves the accuracy of superimposing the pattern 10p onto the various configurations already formed on the wafer 20 in previous processes when transferring the pattern 10p of the template 10 to the resist film 30.

[0100] The improved superposition accuracy of pattern 10p means that, for example, if the imprint process described above is for forming wiring on the workpiece film 21, the contacts already formed in the lower layer of the workpiece film 21 and the wiring on the workpiece film 21 will be connected more reliably.

[0101] Furthermore, for example, if the imprinting process described above is a process for forming contacts on the workpiece film 21, the wiring already formed in the lower layer of the workpiece film 21 and the contacts on the workpiece film 21 will be connected more reliably.

[0102] (Example of imprint device operation) Next, a detailed example of the alignment operation by the imprint device 1 of the embodiment will be described using Figure 7.

[0103] Figure 7 shows an example of the alignment operation performed by the imprint apparatus 1 according to the embodiment. Figures 7(a) and (d) are top views of the template 10 as seen from above, with the template 10 pressed against the resist film 30. Figures 7(b) and (e) are schematic diagrams of the state when the template 10 is pressed against the resist film 30, as seen from the side. Figures 7(c) and (f) are graphs showing the alignment operation performed by the imprint apparatus 1 during alignment. Figure 7(g) is a graph showing other alignment operations performed by the imprint apparatus 1 during alignment.

[0104] In performing the alignment operation, the control unit 90 of the imprint apparatus 1 presses the template 10 against the resist film 30 on the wafer 20 and continuously images the multiple alignment marks 10a on the template 10 with the image sensor 83. The control unit 90 also determines, based on the images captured by the image sensor 83, that the resist film 30 has filled the recesses of these alignment marks 10a.

[0105] Once the resist film 30 is filled into the alignment mark 10a and the visibility of the overlapping alignment marks 10a and the alignment mark 20a on the wafer 20 is improved, the control unit 90 causes the image sensors 84a to 84d to image these alignment marks 10a and 20a, and aligns the alignment marks 10a and 20a based on these images.

[0106] Figures 7(a) to 7(c) show examples of alignment operations performed by the imprint device 1 during imprint processing on a shot area SH without defects.

[0107] As shown in Figure 7(a), when performing the alignment operation, the control unit 90 causes the image sensors 84a to 84d to image specific alignment marks 10a and 20a from among the multiple alignment marks 10a and 20a present in the shot area SH.

[0108] In the example shown in Figure 7(a), the control unit 90 causes the image sensor 84a to capture the alignment marks 10a and 20a in the upper left corner of the rectangular shot area SH, the image sensor 84b to capture the alignment marks 10a and 20a in the upper right corner of the paper, the image sensor 84c to capture the alignment marks 10a and 20a in the lower right corner of the paper, and the image sensor 84d to capture the alignment marks 10a and 20a in the lower left corner of the paper.

[0109] Thus, during the alignment operation, it is preferable to utilize all of the image sensors 84a to 84d of the imprint device 1, for example, to capture alignment marks 10a and 20a that are as far apart as possible from each other, such as the four corners of the shot area SH, and perform the alignment based on these images. This makes it possible to detect the amount of positional misalignment across the entire shot area SH and improve the superposition accuracy of the pattern 10p of the template 10.

[0110] As shown in Figure 7(b), when the control unit 90 brings the template 10 into contact with the resist film 30 (see Figure 5(b)), the pressure unit 813 (see Figure 3) of the template stage 81 pressurizes the back surface of the template 10, causing the surface of the template 10 on which the pattern 10p (see Figure 3) is formed to bend toward the wafer 20.

[0111] Furthermore, the control unit 90 sequentially observes the alignment marks 10a and 20a at the four corners of the shot area SH using the image sensors 84a to 84d, and finely adjusts the position of the template 10 relative to the wafer 20 in the X and Y directions using, for example, the drive unit 814 of the template stage 81 (see Figure 3).

[0112] As shown in Figure 7(c), the alignment error, which was fluctuating significantly while waiting for the resist film 30 to fill the alignment marks 10a of the template 10, gradually decreases in amplitude once alignment begins. After the alignment error falls below a predetermined threshold, or after a predetermined time has elapsed, the control unit 90 controls the light source 89 to irradiate it with ultraviolet light or the like to expose the resist film 30.

[0113] Furthermore, the chip-free shot region SH shown in Figure 7(a), etc., is located closer to the center of the wafer 20 than to the edge, and is, for example, placed in a position that overlaps with any of zones Z1 to Z4 of the wafer chuck 82b, or spans multiple regions of these zones Z1 to Z4.

[0114] The control unit 90 maintains a constant suction force in at least these zones Z1 to Z4, or in addition to these, zone Z5, during the alignment operation. As a result, a constant negative pressure is applied to the back surface of the wafer 20 that overlaps with the shot area SH that is the target of the imprint process.

[0115] Figures 7(d) to 7(g) show examples of alignment operations performed by the imprint device 1 during imprint processing on the missing shot region SHc.

[0116] In the example shown in Figure 7(d), the chipped shot region SHc is located near the wafer edge 20e in the lower right position on the wafer surface 20, and the chipped portion in the lower right of the chipped shot region SHc is placed in a position that overlaps with zone Z5 of the wafer chuck 82b.

[0117] As shown in Figure 7(d), when performing alignment operations in the missing shot region SHc, the control unit 90 causes the image sensors 84a to 84d to image specific alignment marks 10a and 20a from among the multiple alignment marks 10a and 20a present in the missing shot region SHc.

[0118] In the example shown in Figure 7(d), the control unit 90 causes the image sensor 84a to capture the alignment marks 10a and 20a in the upper left corner of the missing shot region SHc, the image sensor 84b to capture the alignment marks 10a and 20a in the upper right corner of the paper, and the image sensor 84d to capture the alignment marks 10a and 20a in the lower left corner of the paper.

[0119] However, as described above, the missing shot region SHc shown in Figure 7(d) has a missing area in the lower right of the paper, and therefore the alignment marks 10a and 20a, which are normally located in this position, cannot be imaged. The control unit 90 causes the image sensor 84c, which is supposed to image the lower right of the paper in the shot region SH without the missing area, to image the alignment marks 10a and 20a, which are located in a position that overlaps with zone Z5.

[0120] As shown in Figure 7(e), in the imprinting process for the missing shot region SHc, the control unit 90 also applies pressure to the back surface of the template 10 using the pressure unit 813 of the template stage 81 when bringing the template 10 into contact with the resist film 30, causing the surface of the template 10 on which the pattern 10p is formed to bend toward the wafer 20.

[0121] Furthermore, the control unit 90 controls the wafer chuck 82b so that the pressure in zone 5 is negative relative to the reference pressure. The reference pressure is the pressure in the environment where the imprinting process is performed inside the imprint apparatus 1, for example, atmospheric pressure. The control unit 90 also makes the zones inside zone 5, at least zone 4 adjacent to zone 5, positive relative to the reference pressure. The control unit 90 also makes the zones further inside negative relative to the reference pressure.

[0122] As a result, the portion of the wafer 20 that overlaps with the positive pressure zone near the wafer edge 20e bends towards the template 10, while the portion from the negative pressure zone 5 to the wafer edge 20e bends downward.

[0123] In this way, by bending both the template 10 and the wafer 20, the template 10 can be pressed against the resist film 30 while maintaining the pattern 10e of the template 10 and the pattern transfer surface of the wafer 20 to be approximately parallel. In addition, the resist film 30 becomes more easily filled into the pattern 10p of the template 10.

[0124] The control unit 90 sequentially observes, for example, the alignment marks 10a and 20a that overlap with zone 5 of the shot area SH, as well as other alignment marks 10a and 20a, using the image sensors 84a to 84d, and adjusts them so that the amount of positional displacement of each alignment mark 10a and 20a is minimized.

[0125] As shown in Figure 7(f), the control unit 90 observes the alignment marks 10a and 20a, which are located in positions other than those overlapping with zone 5, using the image sensors 84a, 84b, and 84d, and fine-tunes the position of the template 10 relative to the wafer 20 in the X and Y directions using, for example, the drive unit 814 of the template stage 81, so that the amplitude of the alignment error is reduced.

[0126] After the alignment error falls below a predetermined threshold, or after a predetermined time has elapsed, the control unit 90 controls the light source 89 to irradiate it with ultraviolet light or the like to expose the resist film 30.

[0127] As shown in Figure 7(g), the control unit 90, in parallel with the alignment operation by adjusting the position of the template 10, for example, observes the alignment marks 10a and 20a at positions overlapping with zone 5 using the image sensor 84c, and controls the wafer chuck 82b to adjust the suction force, i.e., the negative pressure, in zone 5.

[0128] The pressure in Zone 5 is initially set to a predetermined pressure, such as 0 kPa, which is below the reference pressure (atmospheric pressure). In parallel with the position adjustment of the template 10, the control unit 90 gradually reduces the pressure in Zone 5, for example, from 0 kPa to -10 kPa, -15 kPa, etc. At this time, the control unit 90 can reduce the pressure in Zone 5 in increments of, for example, -2.5 kPa.

[0129] In this way, as the pressure is reduced, the suction force in zone 5 increases, and the downward curvature of the portion of the chipped shot area SHc that overlaps with zone 5 to the wafer edge 20e increases. In addition, the relative positional relationship of the alignment marks 10a and 20a at the position overlapping with zone 5 also changes accordingly. This is because the amount of deflection of the template 10 superimposed on the wafer 20 due to pressure does not change significantly compared to the amount of curvature of the wafer edge 20e.

[0130] Based on the positional changes of these alignment marks 10a and 20a, the control unit 90 adjusts the pressure in zone 5 to minimize the alignment error of these alignment marks 10a and 20a. Even during such alignment operations, it is thought that the alignment error of these alignment marks 10a and 20a will fluctuate in a way that gradually decreases in amplitude, similar to Figure 7(f) above.

[0131] As described above, in the chipped shot region SHc, there are chips in one or more of the four corners, and one or more image sensors 84 that were supposed to be used to image the alignment marks 10a and 20a that should be located at these positions and to adjust the position of the template 10 in the X and Y directions relative to the wafer 20 become unused. By using one or more of these image sensors 84 to observe the alignment marks 10a and 20a located in a position overlapping with zone 5, and changing the pressure to minimize the alignment error, it is possible to optimize the amount of warping of the wafer 20.

[0132] Subsequently, as described above, exposure of the resist film 30 is performed after the alignment errors of the alignment marks 10a and 20a other than those overlapping with zone 5 fall below a predetermined threshold, or after a predetermined time has elapsed since the start of the alignment operation based on these alignment marks 10a and 20a.

[0133] However, if a predetermined threshold is set for the alignment error of these alignment marks 10a and 20a, a predetermined threshold may also be set for the alignment error of the alignment marks 10a and 20a that overlap with zone 5.

[0134] In this case, the alignment operation can be terminated and the resist film 30 can be exposed when at least one of the alignment errors of the alignment marks 10a and 20a outside of zone 5, and the alignment errors of the alignment marks 10a and 20a in zone 5, falls below the corresponding threshold.

[0135] Alternatively, the alignment operation may be terminated and the resist film 30 exposed when both of these alignment errors fall below the corresponding threshold.

[0136] The alignment operation shown in Figure 7(g) optimizes the amount of warpage of the wafer 20 so as to satisfy both the filling of the resist film 30 into the pattern 10p of the template 10 and the superposition accuracy of the pattern 10p near the area overlapping with zone 5 of the chipped shot region SHc.

[0137] Furthermore, the alignment marks 10a and 20a located in positions overlapping with Zone 5 may be used not only for adjusting the amount of warpage of the wafer 20 by adjusting the pressure in Zone Z5, but also for the same purposes as the alignment marks 10a and 20a located in positions other than those overlapping with Zone 5. That is, the amount of warpage of the wafer 20 may be adjusted by adjusting the pressure in Zone Z5, while simultaneously observing the alignment marks 10a and 20a located in positions overlapping with Zone 5 and adjusting the position of the template 10 and wafer 20 in the X and Y directions.

[0138] (Comparative example) During the imprint process using the imprint apparatus, the wafer is held in place by a wafer chuck to prevent the wafer from peeling off the wafer stage while simultaneously releasing the template. Multiple shot areas are provided on the wafer, and the imprint process is performed on each individual shot area.

[0139] Here, the release force applied to the wafer depends on the position of the shot area, etc. For this reason, a zone-divided wafer chuck can be used, for example, to control the suction force of the wafer chuck for each individual shot area. This allows the suction force of the wafer chuck to be adjusted in real time for the shot area being processed as the imprint process progresses.

[0140] However, each chipped shot region has a different shape and area. The release force applied to the wafer also differs depending on the area of ​​the shot region. Therefore, if a predetermined suction force is uniformly applied to chipped shot regions located at the wafer edge, the amount of wafer warping will vary for each chipped shot region. This, in turn, will cause variations in the pattern overlap accuracy. Figure 8 shows the relationship between wafer warping and pattern overlap accuracy.

[0141] Figure 8 is a schematic diagram showing the relationship between the relative positions of the alignment marks 10xa and 20xa on the template 10x and wafer 20x in the comparative example and the amount of warpage of the wafer 20x.

[0142] As shown in Figure 8, the comparative example wafer 20x is placed on the comparative example wafer chuck 82x. The comparative example template 10x is also superimposed on the wafer 20x.

[0143] As shown in Figure 8(a), for example, no suction is performed by the wafer chuck 82x, and the wafer 20x is not warped. The template 10x is then placed on top of the wafer 20x so that it is approximately parallel to it. In this state, the alignment marks 20xa on the wafer 20x and the alignment marks 10xa on the template 10x coincide in the vertical direction.

[0144] As shown in Figure 8(b), for example, when suction is performed by a wafer chuck 82x and the wafer 20x is warped, a template 10x is placed on top of the wafer 20x so that it is approximately parallel to the wafer 20x. In this case, a misalignment occurs between the alignment marks 10xa and 20xa that were previously overlapping.

[0145] This is because the wafer 20x warps when it is adsorbed onto the wafer chuck 82x, while the template 10 superimposed on the wafer 20 is hardly affected by the wafer chuck 82x.

[0146] From the above, it can be seen that the greater the wafer warp, the lower the pattern overlapping accuracy. On the other hand, if the wafer warp is too small, the packing of the resist film into the template pattern will decrease. Therefore, there is an optimal value for the amount of wafer warp when imprinting on chipped shot areas at the wafer edge. Furthermore, the suction force of the wafer chuck required to maintain the appropriate amount of wafer warp may differ for each chipped shot area, which has a different area, as described above.

[0147] According to the pattern formation method of this embodiment, the relative position of the template 10 and the wafer 20 in the plane direction is adjusted while observing the alignment marks 10a and 20a outside zone 5 to align these alignment marks 10a and 20a, and the amount of warping of the wafer edge 20e is changed by adjusting the suction force of the wafer chuck 82b in zone 5 while observing the alignment marks 10a and 20a in zone 5 to align these alignment marks 10a and 20a.

[0148] This allows for the adjustment of the wafer 20's warp in real time for each individual chipped shot region SHc, rather than applying a uniform negative pressure from the wafer chuck 82b to the chipped shot region SHc located on the wafer edge 20e during imprinting. Therefore, the accuracy of the pattern 10p of the template 10 on the wafer 20 can be improved.

[0149] According to the pattern formation method of this embodiment, the alignment of alignment marks 10a and 20a outside zone 5 and the alignment of alignment marks 10a and 20a within zone 5 are performed in parallel. This makes it possible to efficiently align the template 10 and the wafer 20 in the plane direction and optimize the amount of warping of the wafer 20.

[0150] According to the pattern forming method of this embodiment, the alignment marks 10a and 20a in zone 5 of the wafer chuck 82b are aligned while gradually increasing the suction force in zone 5. In this way, the amount of warping of the wafer 20 is adjusted in a direction that increases the highly responsive suction force, so that the alignment marks 10a and 20a in zone 5 can be aligned quickly.

[0151] According to the pattern forming method of this embodiment, after the resist film 30 is filled into the recess of the alignment mark 10a used for alignment with the alignment mark 20a of zone 5, the alignment of these alignment marks 10a and 20a is started. This allows the alignment of the alignment marks 10a and 20a to be performed while their visibility is enhanced.

[0152] According to the imprint apparatus 1 of the embodiment, based on an image of alignment marks 10a and 20a outside zone 5 captured by some of the image sensors 84a to 84d, the relative position of the template 10 and the wafer 20 in the plane direction is adjusted to align these alignment marks 10a and 20a. At the same time, based on an image of alignment marks 10a and 20a in zone 5 captured by the unused image sensor 84 of the image sensors 84a to 84d, the suction force of the wafer chuck 82b in zone 5 is adjusted to change the amount of warping of the wafer edge 20e, thereby aligning these alignment marks 10a and 20a.

[0153] This allows for optimizing the amount of warpage of the wafer edge 20e during imprint processing on the defective shot area, for example, by using the image sensor 84, which was not used in the imprint processing of the comparative example. Therefore, without adding any further configuration to the imprint apparatus 1, the amount of warpage of the wafer 20 can be optimized in real time for each defective shot area SHc, and the accuracy of superimposing the pattern 10p of the template 10 onto the wafer 20 can be improved.

[0154] (modified version) Next, the configuration of a modified example of the embodiment will be described using Figure 9. The imprinting device of the modified example differs from the embodiment described above in that it observes the alignment marks 10a and 20a in zone 5 while also adjusting the tilt of the template 10.

[0155] In the following, the overall configuration and individual parts of the imprint device 1 of the above embodiment will be referenced and described using the same reference numerals.

[0156] Figure 9 shows an example of alignment operations performed by an imprint apparatus according to a modified embodiment. Figure 9(a) is a top view of the template 10 as seen from above, with the template 10 pressed against the resist film 30. Figures 9(b) to (d) are schematic diagrams of the state when the template 10 is pressed against the resist film 30, viewed from the side. Figure 9(e) is a graph showing the alignment operations performed by the imprint apparatus 1 during alignment. Figure 9(f) is a graph showing other alignment operations performed by the imprint apparatus 1 during alignment.

[0157] As shown in Figure 9(a), in the missing shot region SHc where the lower right of the paper is missing, similar to the example in Figure 7(d) of the above embodiment, for example, image sensors 84a, 84b, and 84d are used to observe alignment marks 10a and 20a located outside the position overlapping with zone Z5. In addition, the unused image sensor 84c is used to observe alignment marks 10a and 20a located overlapping with zone Z5.

[0158] As shown in Figure 9(b), while observing the alignment marks 10a and 20a outside zone Z5, the drive unit 814 of the template stage 81 adjusts the position of the template 10 and the wafer 20 in the X and Y directions. In addition, while observing the alignment marks 10a and 20a in zone Z5, the suction force on the back surface of the wafer 20 is changed by the wafer chuck 82b to adjust the amount of warping of the wafer 20.

[0159] The first half of the alignment operation, labeled "pressure adjustment" in Figure 9(e), and the first half of the pressure change in zone Z5 in Figure 9(f), which overlaps with the "pressure adjustment" period, correspond to the execution period of the process shown in Figure 9(b) above.

[0160] In this modified alignment operation, for example, the duration of the alignment operation for alignment marks 10a and 20a in zone Z5 can be set to be shorter than the duration of the alignment operation for alignment marks 10a and 20a outside zone Z5, and the alignment operation in zone Z5 can be set to time out before the alignment operation outside zone Z5.

[0161] Furthermore, if the alignment error of the alignment marks 10a and 20a in zone Z5 does not fall below a predetermined threshold and a timeout occurs, the control unit 90 continues to observe the alignment marks 10a and 20a in zone Z5 and uses the template stage 81 to adjust at least one of the tilt of the template 10, the pressing force, and the amount of deflection toward the wafer 20 to align these alignment marks 10a and 20a.

[0162] During the imprinting process on the chipped shot region SHc located on the wafer edge 20e, the tilt of the template 10, the pressing force, and the amount of deflection toward the wafer 20, as described above, all affect the filling of the resist film 30 into the pattern 10p of the template 10 and the amount of warping of the wafer edge 20e. This is because the balance of forces applied to each part of the chipped shot region SHc when the template 10 is pressed changes depending on the tilt of the template 10, the pressing force, and the amount of deflection toward the wafer 20.

[0163] More specifically, for example, if the template 10 is tilted relative to the wafer 20, the force applied to the wafer 20 will be stronger on the side of the template 10 that is tilted towards the wafer 20, and the amount of warping of the wafer 20 may differ.

[0164] Furthermore, as described above, the imprinting force of the template 10 is the force that presses the four corners of the template 10 against the wafer 20. Therefore, by increasing the imprinting force of the template 10, for example, the force applied to the outer periphery of the chipped shot area SHc becomes stronger compared to the central part, and if that part is close to the wafer edge 20e, the amount of warping of the wafer 20 may increase. Conversely, by decreasing the imprinting force of the template 10, for example, the force applied to the outer periphery of the chipped shot area SHc becomes weaker compared to the central part, and the amount of warping of the wafer 20 may decrease.

[0165] Furthermore, if the pressure applied to the back of the template 10 is low, the amount of deflection of the template 10 toward the wafer 20 will be small, and the force may be applied more evenly across the entire surface of the chipped shot region SHc, for example, potentially reducing the amount of warping of the wafer 20. Conversely, if the pressure applied to the back of the template 10 is high, the amount of deflection of the template 10 toward the wafer 20 will be large, and if that part is close to the wafer edge 20e, the amount of warping of the wafer 20 may increase.

[0166] Therefore, by controlling the tilt, pressing force, and amount of deflection toward the wafer 20 of the template 10, the amount of warping of the wafer edge 20e can be adjusted to align the alignment marks 10a and 20a in zone Z5. Specific examples are shown in Figures 9(c) and 9(d).

[0167] As shown in Figure 9(c), after the adjustment of the amount of warpage of the wafer 20 by controlling the suction force of the wafer chuck 82b times out, the control unit 90 continues to observe the alignment marks 10a and 20a in zone Z5, for example, and controls the drive unit 814 of the template stage 81 to adjust the tilt of the template 10 relative to the wafer 20.

[0168] As shown in Figure 9(d), after the adjustment of the amount of warping of the wafer 20 by controlling the suction force of the wafer chuck 82b has timed out, the control unit 90 can also adjust the pressing force of the template 10 by controlling the drive unit 814 of the template stage 81, while continuing to observe the alignment marks 10a, 20a in zone Z5, for example.

[0169] Furthermore, the control unit 90 can also, for example, continue to observe the alignment marks 10a and 20a in zone Z5, and control the pressurizing section 813 of the template stage 81 to change the pressure on the back of the template 10, thereby adjusting the amount of deflection of the template 10 toward the wafer 20.

[0170] As shown in Figure 9(e), even after the pressure adjustment period in zone Z5, by continuing to adjust at least one of the tilt, pressing force, and amount of deflection toward the wafer 20 using the alignment marks 10a and 20a in zone Z5, in parallel with the planar alignment of the template 10 and the wafer 20 using the alignment marks 10a and 20a outside zone Z5, the amplitude of the alignment error can be further suppressed, and the pattern 10p of the template 10 can be transferred to the resist film 30 with good superposition accuracy.

[0171] As shown in Figure 9(f), after the pressure adjustment period in zone Z5, while the tilt of the template 10, the pressing force, and the amount of deflection toward the wafer 20 are being adjusted, the suction force in zone 5 is maintained at the appropriate value obtained when the pressure adjustment period in zone Z5 timed out.

[0172] Of the inclination of the template 10, the stamping force, and the amount of deflection toward the wafer 20, the amount of warping of the wafer 20 is more significantly affected by the inclination of the template 10, second only to the adjustment of the suction force in zone Z5. Furthermore, the stamping force and the amount of deflection of the template 10 have a similar (in opposite) effect in that they change the balance of forces applied to the central and outer edges of the chipped shot region SHc.

[0173] Therefore, after the pressure adjustment period in zone Z5 has timed out, among the tilt of the template 10, the pressing force, and the amount of deflection toward the wafer 20, for example, the tilt adjustment of the template 10 can be prioritized.

[0174] In this case, if the alignment error of the alignment marks 10a and 20a in zone Z5 does not fall below a predetermined threshold and a timeout occurs again, either the pressing force of the template 10 or the amount of deflection toward the wafer 20 may be adjusted. Subsequently, if the alignment error of the alignment marks 10a and 20a in zone Z5 falls below a predetermined threshold, or if the alignment operation of the alignment marks 10a and 20a outside zone Z5 times out, the adjustment of the pressing force or deflection amount of the template 10 may be terminated.

[0175] Furthermore, when adjusting the pressure in zone Z5, the tilt of the template 10, the stamping force, and the amount of deflection, the alignment marks 10a and 20a in zone Z5 may be used for planar alignment between the template 10 and the wafer 20, similar to the other alignment marks 10a and 20a outside zone Z5.

[0176] According to the modified pattern forming method, the relative position between the template 10 and the wafer 20 is adjusted, the suction force in zone 5 of the wafer chuck 82b is adjusted, and at least one of the tilt of the template 10, the force pressing the pattern 10p against it, and the deflection of the pattern 10p due to back pressure adjustment of the template 10 is adjusted to align the alignment marks in zone 5. This further improves the accuracy of the superposition of the pattern 10p of the template 10 with respect to the wafer 20.

[0177] According to the modified pattern forming method, after aligning the alignment marks 10a and 20a outside zone 5 in parallel with aligning these alignment marks 10a and 20a, if the alignment state of the alignment marks 10a and 20a in zone Z5 does not meet predetermined conditions, the alignment marks 10a and 20a in zone Z5 are aligned by adjusting at least one of the inclination of the template 10, the force pressing the pattern 10p, and the deflection of the pattern 10p in parallel with aligning the alignment marks 10a and 20a outside zone Z5.

[0178] In this way, after adjusting the pressure of the wafer chuck 82b to be more effective in adjusting the amount of warpage of the wafer 20, if the predetermined alignment conditions are not met, the alignment marks 10a and 20a can be efficiently and precisely aligned by further adjusting at least one of the inclination of the template 10, the force pressing the pattern 10p against it, and the deflection of the pattern 10p.

[0179] The modified pattern formation method achieves the same effects as the pattern formation method of the above-described embodiment.

[0180] In the embodiments and modifications described above, examples were given in which bar-in-bar type marks were used as alignment marks 10a and 20a. However, as mentioned above, the alignment marks provided on the template 10 and wafer 20 may be of a different type than bar-in-bar type marks. As an example of other marks, a moiré type mark is shown in Figure 10.

[0181] Figure 10 is a top view showing an example of the configuration of a template and moiré-type alignment marks 110a, 120a provided on a wafer according to another modification of the embodiment.

[0182] As shown in Figure 10(a), the template side of other modified examples is provided with alignment marks 110a having a one-dimensional periodic structure in which multiple lines and spaces extending in the direction along the Y direction are arranged in the X direction at a constant distance from each other.

[0183] Furthermore, in other modified examples, the wafer side is provided with alignment marks 120a having a checkerboard (check pattern) shaped two-dimensional periodic structure arranged at equal intervals in the X and Y directions. The period in the X direction of the structure of alignment marks 120a is slightly different from the period in the X direction of alignment marks 110a.

[0184] With this configuration, when alignment marks 110a and 120a are superimposed vertically, interference fringes called moiré patterns are generated. Furthermore, when the relative position between the template and the wafer of other modified examples is moved in the X direction while alignment marks 110a and 120a are superimposed, the interference fringes move in the X direction.

[0185] By detecting the movement of these interference fringes as a signal waveform in an image captured by, for example, the image sensor 84 described above, the amount of positional displacement in the X direction between the template and the wafer can be calculated.

[0186] On the other hand, to detect the amount of misalignment between the template and the wafer in the Y direction, the alignment marks 110a and 120a in Figure 10 can both be rotated by 90° and placed on the template and the wafer. As a result, the alignment marks 110a and 120a will have slightly different periods in the Y direction relative to each other.

[0187] By overlapping these alignment marks 110a and 120a vertically and moving the relative position between the template and the wafer in the Y direction, interference fringes move in the Y direction.

[0188] By detecting the movement of these interference fringes as a signal waveform in an image captured by the image sensor 84 described above, for example, the amount of positional displacement in the Y direction between the template and the wafer can be calculated.

[0189] As described above, by detecting and analyzing interference fringes in moiré-type alignment marks 110a and 120a as electrical signals, for example, the amount of misalignment between the template and the wafer can be quantified with higher accuracy, and the alignment of the template and the wafer can be performed more precisely.

[0190] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of symbols]

[0191] 1...Imprint device, 10...Template, 10a, 20a, 110a, 120a...Alignment marks, 10p...Pattern, 20...Wafer, 21...Workpiece film, 30...Resist film, 81...Template stage, 812...Template chuck, 813...Pressure unit, 814...Drive unit, 82...Wafer stage, 82b...Wafer chuck, 83, 84a~84d...Image sensor, 90...Control unit, SH...Shot area, SHc...Cracked shot area, Z1~Z5...Zone.

Claims

1. A substrate having multiple shot regions is held on a suction chuck having a first suction region for suctioning the outer edge of the substrate and a second suction region for suctioning the inner region of the outer edge. A resin film is formed on at least one of the plurality of shot regions. A pattern forming method comprising pressing a template pattern onto the resin film on one shot region to transfer the pattern to the resin film, The aforementioned multiple shot regions are Distended across the outer edge and the inner region, having a first alignment mark in the inner region and a second alignment mark in the outer edge, including a first shot region that is partially missing on the outer edge side, The aforementioned template is It has a third alignment mark used for alignment with the first alignment mark, and a fourth alignment mark used for alignment with the second alignment mark. When transferring the pattern to the resin film on the first shot region, With the template pressed against the resin film, the first and third alignment marks are aligned, and while observing the second and fourth alignment marks through the template, the pressure in the first suction region is made negative relative to the reference pressure, and the pressure in the second suction region is made positive relative to the reference pressure, thereby pressurizing the back surface of the substrate in the inner region, thereby changing the amount of warping of the outer edge and the inner region, and aligning the second and fourth alignment marks. Pattern formation method.

2. When transferring the pattern to the resin film on the first shot region, The pressure in the first suction region is set to a first pressure that is negative relative to the reference pressure, and then the pressure is gradually changed to a second pressure that is even more negative than the first pressure, while aligning the second and fourth alignment marks. The pattern forming method according to claim 1.

3. When transferring the pattern to the resin film on the first shot region, The second and fourth alignment marks are aligned by adjusting at least one of the inclination of the template, the force pressing the pattern, and the deflection of the pattern. The pattern forming method according to claim 1.

4. The suction chuck has a third suction region that sucks a region further inside the inner region, When transferring the pattern to the resin film on the first shot region, The pressure in the first suction region is set to negative pressure, the pressure in the second suction region is set to positive pressure, and the pressure in the third suction region is set to negative pressure relative to the reference pressure. The pattern forming method according to claim 1.

5. A substrate on which a film to be processed is formed and which has multiple shot regions is held on a suction chuck having a first suction region for suctioning the outer edge of the substrate and a second suction region for suctioning the inner region of the outer edge. A resin film is formed on at least one of the plurality of shot regions. The pattern of the template is pressed onto the resin film on the aforementioned shot area, thereby transferring the pattern to the resin film. A method for manufacturing a semiconductor device, comprising processing the film to be processed via the pattern transferred to the resin film, The aforementioned multiple shot regions are Distended across the outer edge and the inner region, having a first alignment mark in the inner region and a second alignment mark in the outer edge, including a first shot region that is partially missing on the outer edge side, The aforementioned template is It has a third alignment mark used for alignment with the first alignment mark, and a fourth alignment mark used for alignment with the second alignment mark. When transferring the pattern to the resin film on the first shot region, With the template pressed against the resin film, the first and third alignment marks are aligned, and while observing the second and fourth alignment marks through the template, the pressure in the first suction region is made negative relative to the reference pressure, and the pressure in the second suction region is made positive relative to the reference pressure, thereby pressurizing the back surface of the substrate in the inner region, thereby changing the amount of warping of the outer edge and the inner region, and aligning the second and fourth alignment marks. A method for manufacturing a semiconductor device.

6. A suction chuck is configured to hold a substrate having multiple shot regions, and has a first suction region for sucking the outer edge of the substrate and a second suction region for sucking the inner region of the outer edge. A template stage holds a template with the patterned surface facing the substrate, adjusts the relative position of the substrate and the template in the planar direction, and moves the template up and down relative to the substrate. A first image sensor and a second image sensor that image the substrate via the template, The system comprises the suction chuck, the template stage, and a control unit for controlling the first and second image sensors, The aforementioned multiple shot regions are Distended across the outer edge and the inner region, having a first alignment mark in the inner region and a second alignment mark in the outer edge, including a first shot region that is partially missing on the outer edge side, The aforementioned template is It has a third alignment mark used for alignment with the first alignment mark, and a fourth alignment mark used for alignment with the second alignment mark. The control unit, The suction chuck is used to suck the outer edge and inner region of the held substrate, With the template pressed against the resin film formed on the first shot area, the first and third alignment marks are aligned based on images captured by the first image sensor through the template, and the second and fourth alignment marks are aligned based on images captured by the second image sensor. The pressure in the first suction area is made negative relative to the reference pressure by the suction chuck, and the pressure in the second suction area is made positive relative to the reference pressure by the suction chuck, thereby pressurizing the back surface of the substrate in the inner area, changing the amount of warping of the outer edge and the inner area, and aligning the second and fourth alignment marks. Imprinting device.

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