JP2020009994A - Planarization device, planarization method and method for manufacturing articles - Google Patents

Abstract

To provide a technique useful in planarizing a composition on a substrate.SOLUTION: A planarization device is arranged to planarize a composition on a substrate by using a mold. The planarization device has a mechanism of putting the mold into contact with the composition disposed on the substrate to planarize the composition and then, bringing the mold away from the composition. A mold holding part has a holding face for holding a region outside a region including a center position of the mold. The holding face has a geometry such that a point therein is located at a higher position closer to the outer periphery of the mold holding part. While the mold held on the holding face is kept in contact with the composition in a first region including a center position of the substrate, the composition in the first region is planarized in the state of being separated from the composition in a second region outside the first region of the substrate and then, the composition in the first region and the mold are separated.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a flattening device, a flattening method, and a method of manufacturing an article.

  As the demand for miniaturization of semiconductor devices advances, in addition to the conventional photolithography technology, a micro-processing technology that forms an uncured composition on a substrate with a mold and cures it to form a pattern of the composition on the substrate has been developed. Attention has been paid. Such a technique is called an imprint technique, and can form a fine pattern on the order of several nanometers on a substrate.

  One of the imprint techniques is, for example, a photo-curing method. An imprint apparatus employing a photocuring method molds a photocurable composition supplied to a shot area on a substrate with a mold, irradiates light to cure the composition, and forms a mold from the cured composition. By separating, a pattern is formed on the substrate.

  In recent years, a technique for planarizing a composition on a substrate has been proposed (see Patent Document 1). The technique disclosed in Patent Literature 1 aims to improve the accuracy of flattening by dropping a composition based on a step of a substrate and curing the composition in a state where a flat surface of a mold is in contact with the dropped composition. Things.

JP 2011-529626 A

  However, in the conventional flattening apparatus, the mold release force is increased because the composition on the substrate is brought into contact with the mold in a larger area than the imprint apparatus and then separated. When the release force is increased, the release operation itself cannot be performed normally, or the composition on the substrate is not properly planarized.

  Therefore, an object of the present invention is to provide a technique advantageous for flattening a composition on a substrate.

  A flattening apparatus according to one aspect of the present invention for solving the above-mentioned problems is a flattening apparatus for flattening a composition on a substrate using a mold, wherein the substrate holding section holding the substrate and the mold are held. A mold holding unit, and a mechanism for bringing the composition and the mold disposed on the substrate into contact with each other to flatten the composition and then releasing the composition and the mold, and the mold holding unit is provided at a center of the mold. A holding surface that holds a region outside a region including a position, wherein the holding surface has a shape in which a position increases toward an outer periphery of the mold holding unit, and the mechanism is held by the holding surface. The mold on the first region is separated from the composition on the second region outside the first region of the substrate while the mold is in contact with the composition on the first region including the center position of the substrate. Flattening the object, and separating the mold and the composition on the first region. And butterflies.

  ADVANTAGE OF THE INVENTION According to this invention, the technique advantageous in planarizing the composition on a board | substrate can be provided.

It is the schematic which shows the structure of a flattening apparatus. FIG. 9 is a diagram for describing an outline of a flattening process. FIG. 4 is a cross-sectional view when a substrate is brought into contact with a mold during a planarization process. It is an expanded sectional view at the time of making a board | substrate contact the board | substrate at the time of a planarization process. 5 is a flowchart for explaining a flattening process in the flattening device.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In each of the drawings, the same members are denoted by the same reference numerals, and redundant description will be omitted.

  FIG. 1 is a schematic diagram showing the configuration of the planarizing device 100. The flattening device 100 is embodied as a forming device that forms a composition on the substrate 1 using the mold 11 (mold, template). In the present embodiment, the flattening device 100 flattens the composition on the substrate. The planarizing apparatus 100 cures the composition in a state where the composition on the substrate and the mold are in contact with each other, and separates the cured composition from the mold to form a global or local flat surface of the composition on the substrate. To form

  As the substrate, a silicon wafer is a typical base material, but is not limited to this. The substrate 1 may be arbitrarily selected from those known as substrates for semiconductor devices such as aluminum, titanium-tungsten alloy, aluminum-silicon alloy, aluminum-copper-silicon alloy, silicon oxide, and silicon nitride. it can. Note that, as the substrate 1, a substrate in which an adhesion layer is formed by a surface treatment such as a silane coupling treatment, a silazane treatment, and the formation of an organic thin film to improve the adhesion with the curable composition may be used. . The substrate 1 is typically circular with a diameter of 300 mm, but is not limited to this.

  As the mold 11, a mold made of a light transmissive material may be used in consideration of a light irradiation step. Specific examples of the material constituting the mold 11 include glass, quartz, optically transparent resin such as PMMA (Polymethyl methacrylate), polycarbonate resin, transparent metal deposition film, flexible film such as polydimethylsiloxane, and photocuring. Films and metal films are preferred. The mold 11 is preferably a circle having a diameter larger than 300 mm and smaller than 500 mm, but is not limited to this. The thickness of the mold 11 is preferably not less than 0.25 mm and less than 2 mm, but is not limited thereto.

  As the composition, a UV curable liquid is preferably used in consideration of a light irradiation step. Typically, monomers such as acrylates and methacrylates may be used.

  The flattening apparatus 100 includes a substrate chuck 2 (substrate holding unit), a substrate stage 3, a base platen 4, a support 5, a top plate 6, a guide bar plate 7, a guide bar 8, a mold driving unit 9, a support 10, a mold chuck. 12, a head 13, and an alignment shelf 14. The flattening device 100 includes a droplet supply unit 20, an off-axis alignment (OA) scope 21, a substrate transport unit 22, an alignment scope 23, a light source 24, a stage drive unit 31, a mold transport unit 32, a cleaning unit 33, It has a control unit 200. The substrate chuck 2 and the substrate stage 3 constitute a substrate holder for holding the substrate 1, and the mold chuck 12 and the head 13 constitute a mold holder for holding the mold 11. Here, the XYZ coordinate system is defined such that the horizontal plane is the XY plane and the vertical direction is the Z-axis direction.

  Referring to FIG. 1, a substrate 1 is carried in from the outside of the flattening apparatus 100 or from a storage box in which wafers are stored, and is held by a substrate chuck 2 by a substrate transfer unit 22 including a transfer hand or the like. The substrate stage 3 is supported by a base platen 4 and driven in the X-axis direction and the Y-axis direction to position the substrate 1 held by the substrate chuck 2 at a predetermined position. The stage drive unit 31 includes, for example, a linear motor and an air cylinder, and drives (moves) the substrate stage 3 in at least the X-axis direction and the Y-axis direction. (Six axis directions). The stage drive unit 31 includes a rotation mechanism, and drives (rotates) the substrate chuck 2 or the substrate stage 3 around an axis parallel to the Z-axis direction.

  The mold 11 is carried into the outside of the flattening apparatus 100 or from a storage box in which the mold is stored, and is held by the mold chuck 12 (mold holding unit) by a mold transfer unit 32 including a transfer hand or the like. The mold 11 has, for example, a circular or square outer shape, and includes a flat portion 11a on a lower surface. The flat portion 11a has such a rigidity that it comes into contact with the composition on the substrate and follows the surface shape of the substrate 1. The flat portion 11 a has the same size as the substrate 1 or a size larger than the substrate 1. The mold chuck 12 is supported by the head 13 and has a function of correcting the inclination of the mold 11 around the Z axis. Each of the mold chuck 12 and the head 13 includes an opening through which light (ultraviolet light) emitted from the light source 24 via the collimator lens passes. A load cell for measuring the pressing force (imprinting force) of the mold 11 against the composition on the substrate is arranged on the mold chuck 12 or the head 13.

  On the base platen 4, a column 5 for supporting a top plate 6 is arranged. The guide bar 8 penetrates the top plate 6, one end is fixed to the guide bar plate 7, and the other end is fixed to the head 13. The mold driving unit 9 drives the head 13 in the Z-axis direction via the guide bar 8 to bring the mold 11 held by the mold chuck 12 into contact with the composition on the substrate, or from the composition on the substrate. It is a mechanism that separates. Further, the mold driving unit 9 has a function of driving (moving) the head 13 in the X-axis direction and the Y-axis direction, and a function of rotating and driving the mold chuck 12 or the head 13 around an axis parallel to the Z-axis direction. Have.

  The alignment shelf 14 is suspended from the top plate 6 via the column 10. The guide bar 8 penetrates the alignment shelf 14. In addition, a height measuring system (not shown) for measuring the height (flatness) of the substrate 1 held by the substrate chuck 2 is disposed on the alignment shelf 14 using, for example, an oblique incident image shift method. Have been.

  The OA scope 21 is supported by the alignment shelf 14. The OA scope 21 is used for global alignment processing for detecting alignment marks provided in a plurality of shot areas of the substrate 1 and determining respective positions of the plurality of shot areas.

  The alignment scope 23 includes an optical system and an imaging system for observing a reference mark provided on the substrate stage 3 and an alignment mark provided on the mold 11. However, when the mold 11 is not provided with an alignment mark, the alignment scope 23 may not be provided. The alignment scope 23 is used for alignment that measures a relative position between a reference mark provided on the substrate stage 3 and an alignment mark provided on the mold 11 and corrects the positional deviation. By performing a relative alignment between the mold 11 and the substrate 1 by obtaining a positional relationship between the mold 11 and the substrate stage 3 using the alignment scope 23 and obtaining a positional relationship between the substrate stage 3 and the substrate 1 using the OA scope 21. Can be.

  The droplet supply unit 20 is configured by a dispenser including a discharge port (nozzle) that discharges an uncured (liquid) composition to the substrate 1, and drops (disposes) (supplies) a droplet of the composition onto the substrate. . The droplet supply unit 20 can supply a droplet-shaped composition having a minute volume onto a substrate, for example, by employing a piezo jet method or a micro solenoid method. Further, the number of discharge ports in the droplet supply unit 20 is not limited, and may be one (single nozzle) or may exceed 100. That is, a linear nozzle array may be used, or a plurality of linear nozzle arrays may be combined.

  The cleaning unit 33 cleans (cleans) the mold 11 while the mold 11 is held by the mold chuck 12. The cleaning unit 33 removes the composition adhered to the mold 11, particularly, the plane portion 11 a by separating the mold 11 from the cured composition on the substrate. The cleaning unit 33 may, for example, wipe off the composition adhered to the mold 11 or may remove the composition adhered to the mold 11 using UV irradiation, wet cleaning, plasma cleaning, or the like.

  The control unit 200 includes a processing unit such as a CPU, another processor, and an FPGA, and a storage unit such as a memory, and controls the entire flattening apparatus 100. The control unit 200 functions as a processing unit that controls each unit of the planarization apparatus 100 and performs a planarization process. Here, the flattening process is a process of flattening the composition by bringing the flat portion 11a of the mold 11 into contact with the composition on the substrate and causing the flat portion 11a to follow the surface shape of the substrate 1. The flattening process is generally performed in lot units, that is, for each of a plurality of substrates included in the same lot.

  Next, an outline of a conventional flattening process will be described with reference to FIGS. Here, a process of dropping the composition onto the entire surface of the substrate, bringing the composition into contact with the mold, and planarizing the composition will be described. The composition may be planarized.

  First, as shown in FIG. 2A, a plurality of droplets of the composition IM are dropped from the droplet supply unit 20 onto the substrate 1 on which the underlying pattern is formed. FIG. 2A shows a state before the composition 11 is supplied onto the substrate and the mold 11 is brought into contact with the composition IM. Next, as shown in FIG. 2B, the composition IM on the substrate is brought into contact with the plane portion 11a of the mold 11. FIG. 2B shows a state in which the flat portion 11 a of the mold 11 is completely in contact with the composition IM on the substrate, and the flat portion 11 a of the mold 11 follows the surface shape of the substrate 1. Then, in the state shown in FIG. 2B, the composition IM on the substrate is irradiated with light from the light source 24 via the mold 11 to cure the composition IM. Next, as shown in FIG. 2C, the mold 11 is separated from the cured composition IM on the substrate. Thereby, a flattening layer of the composition IM having a uniform thickness can be formed on the entire surface of the substrate 1. FIG. 2C shows a state where a planarizing layer of the composition IM is formed on the substrate.

  When performing such a planarization treatment, it is difficult to bring the large-area mold 11 into contact with the composition on the entire surface of the substrate 1 and then peel off the entire surface. The larger the contact area is, the larger the force required for peeling (release force) is. When the release force is increased, the release operation itself cannot be performed normally, or the composition on the substrate is not properly planarized.

  In order to solve such a problem, in the present embodiment, the shapes of the mold chuck 12 and the substrate chuck 2 will be described later, and the mold 11 or the substrate 1 will be in a warped state when the mold contacts the composition. To If the outer peripheral region of the substrate 1 is warped, it becomes a mold release starting point at which separation of the composition from the mold is started, and the mold is easily released. Once the separation between the mold 11 and the substrate 1 is started, if the treatment is performed for a sufficient time, the mold release is completed, and a composition IM having a desired thickness and flatness is obtained.

  The flattening process in the flattening apparatus 100 according to the present embodiment will be described with reference to FIGS. FIG. 3 is a sectional view showing a state where the mold and the substrate are in contact with each other. FIG. 4 is an enlarged view of the vicinity of the mold holding surface and the periphery of the substrate. FIG. 5 is a flowchart of the flattening process. As described above, the flattening process is performed by the control unit 200 integrally controlling each unit of the flattening apparatus 100.

  In S702, the mold 11 is carried into the flattening apparatus 100 by the mold transport unit 32, and the mold 11 is held by the mold chuck 12. In step S704, setting information regarding the flattening process is obtained. The setting information regarding the flattening process may include the density (period, width, etc.) of the underlying pattern already formed in the first region 1a of the substrate 1, the final thickness of the composition IM (thickness at the time of curing), and the like. .

  In S706, the substrate 1 to be processed among the plurality of substrates included in the same lot is carried into the flattening apparatus 100 by the substrate transport unit 22, and the substrate 1 is held by the substrate chuck 2.

  In S708, the droplet supply unit 20 performs a process of dropping the composition IM onto the substrate 1 carried in in S706 based on the data of the droplet arrangement pattern. A plurality of droplets of the composition IM are arranged on the first region 1a including the center position C of the outer shape of the substrate 1 shown in FIG. 3 and on the second region 1b outside the first region 1a. The second area is, for example, an area where no pattern is formed. For simplification, the composition IM is not shown in FIGS. When a droplet is dropped on the first region 1a of the substrate 1, the final pattern density (roughness / density) of the base of the first region 1a and the final shape of the flattening layer when the composition IM is flattened by the mold are obtained. By calculating the thickness, the total drop amount and drop position are obtained. Note that the composition IM does not have to be disposed in the second region 1b of the substrate 1. Next, a method for creating data of a droplet arrangement pattern for dropping a composition onto a substrate, which is used in a planarizing apparatus, will be described. The data of the droplet arrangement pattern is created in advance by an external computer (information processing device) or a control unit (information processing device) of the flattening device 100. When the external computer creates the data of the droplet arrangement pattern, the control unit of the flattening apparatus 100 acquires the data of the droplet arrangement pattern from the external computer. The information processing apparatus creates data of a first droplet arrangement pattern for dropping the composition by the droplet supply unit 20 on the first region 1a including the center position of the substrate. The first droplet arrangement pattern includes the density (coarse / dense), pitch, width, and the like of the underlying pattern of the first region 1a, and the final thickness of the planarization layer when the composition IM is planarized by the mold. Is required based on

  In S710, the composition on the first region 1a is brought into contact with the mold on the first region 1a by using the mold of the planarization apparatus 100 or the driving mechanism of the substrate, thereby planarizing the composition on the first region 1a. The details will be described below.

  The mold chuck 12 has a central portion 12b and a holding portion 12a outside the central portion 12b. The holding portion 12a has a holding surface 12aa for holding a region outside the region including the center position of the mold, and the mold is fixed on the holding surface 12aa by vacuum suction, adhesion, a fixing member, or the like. . As shown in FIG. 3, the holding surface 12aa has a shape whose position becomes higher toward the outer periphery of the mold chuck 12. That is, the holding surface 12aa is inclined so as to increase toward the outside. The mold 11 can be held in a downwardly convex shape. The substrate chuck 2 has an upwardly convex shape, and has a shape for holding the substrate 1 by suction so as to have an upwardly convex shape. Therefore, before the mold 11 held by the mold chuck 12 and the substrate 1 held by the substrate chuck 2 are brought into contact with each other, the mold 11 is held so as to have a downward convex shape, and the substrate 1 has an upward convex shape. It is held so that it may become the shape of.

  Then, the mold 11 is brought into contact with the composition on the substrate such that the mold 11 follows the substrate 1 from the center position C of the substrate 1 toward the end (outer periphery) of the substrate 1. As shown in FIG. 3, when the mold 11 is brought into contact with the substrate 1, the composition on the first region 1a comes into contact with the mold. However, the composition on the second region 1b is not in contact with the mold 11 on the second region 1b having a predetermined width, for example, 3 mm or less from the edge of the substrate 1. That is, the second region 1b of the substrate 1 is inclined downward toward the outside, but the mold 11 is inclined above the surface of the second region 1b, and the shape or mold in which the mold 11 is warped is upward. It is in a bent state. Thus, the contact between the mold 11 and the substrate 1 is completed in a state where the mold 11 and the substrate 1 are not parallel in the vicinity of the second region 1b. Next, in S712, the composition on the substrate 1 is exposed and cured using curing light. The center part 12b of the mold chuck 12 is made of a material that transmits curing light. Although FIG. 4 shows an area within 3 mm as the width of the second area 1b, it may be 2 mm or less.

  Next, in S714, an operation of separating the mold 11 from the composition on the first region 1a is performed. In the release operation, the release is started from the state where both the mold 11 and the substrate 1 are warped on the second region 1b. First, the composition on the outer peripheral area of the first region 1a becomes a mold release start point, the composition and the mold move away from the mold release start point, and the mold release point moves toward the inside of the first region 1a. The release is completed. As described above, a releasing start point advantageous for releasing is formed in the region on the outer periphery of the first region 1a, and the releasing is easily performed on the entire surface of the substrate while reducing the releasing force.

  As described above, in S710 to S714, the mold held on the holding surface of the mold chuck is brought into contact with the composition on the first region of the substrate while being separated from the composition on the second region. After the upper composition is planarized, the mold and the composition on the first region are separated.

  In S716, the substrate 1 subjected to the planarization processing is carried out from the substrate chuck 2 by the substrate transport unit 22. In S718, it is determined whether or not the flattening process has been performed on all the substrates included in the same lot. If the flattening process has not been performed on all the substrates included in the same lot, the process proceeds to S706 in order to arrange the substrate 1 to be processed next on the substrate chuck 2. On the other hand, if the flattening process has been performed on all the substrates included in the same lot, the process proceeds to S720.

  In S720, the mold 11 held by the mold chuck 12 is washed by the washing unit 33. That is, the composition adhered to the plane portion 11a of the mold 11 is removed. In S722, the cleaned mold 11 is unloaded from the flattening device 100 by the mold transport unit 32.

  In the present embodiment, the flattening process is completed for all the substrates 1 included in the same lot, and the mold 11 is cleaned before the mold 11 is carried out from the flattening apparatus 100. However, the present invention is not limited to this. Not something. For example, the mold 11 may be cleaned even if the flattening process has not been completed for all the substrates 1 included in the same lot. Further, when the flattening device 100 is provided with a detection unit for detecting the adhesion state of the composition on the plane portion 11a of the mold 11, the mold 11 may be washed according to the detection result of the detection unit. Good.

  In the present embodiment, the flattening apparatus is described. However, the present invention can also be applied to a batch imprint in which the entire surface of the substrate is imprinted collectively using a mold on which a pattern is formed. Further, although the light curing method is described, the invention can be applied to a heat curing method.

(Product manufacturing method)
Next, a method of manufacturing an article (semiconductor IC element, liquid crystal display element, color filter, MEMS, or the like) using the above-described flattening apparatus or flattening method will be described. In the manufacturing method, the composition and the mold are brought into contact with the composition arranged on a substrate (a wafer, a glass substrate, and the like) by using the above-described planarization apparatus to cure the composition and the mold. Separating. Then, a step of performing processing such as forming a pattern using a lithography apparatus on the substrate having the planarized composition, and processing the processed substrate in another known processing step, Is manufactured. Other well-known steps include etching, resist stripping, dicing, bonding, packaging, and the like. According to the present manufacturing method, it is possible to manufacture a higher quality article than before.

  Although the preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist.

Claims (10)

In a flattening apparatus for flattening the composition on the substrate using a mold,
A substrate holding unit that holds the substrate,
A mold holding unit for holding the mold,
Having a mechanism for separating the composition and the mold after the composition and the mold arranged in contact with the substrate and contacting the mold to flatten the composition.
The mold holding unit has a holding surface that holds an area outside the area including the center position of the mold,
The holding surface has a shape in which a position is increased toward an outer periphery of the mold holding unit,
The mechanism separates the mold held on the holding surface from the composition on the second area outside the first area of the substrate while contacting the mold on the first area including the center position of the substrate. A planarizing device for planarizing the composition on the first region in a state where the composition is formed, and then separating the mold from the composition on the first region.   2. The flattening device according to claim 1, wherein when the composition on the first region is planarized, the holding surface contacts the composition on the first region in a state in which a mold is warped upward. 3. Device.   The flattening apparatus according to claim 1, wherein when separating the composition from the mold, the mold is separated from the composition on a region around the first region.   The flattening device according to any one of claims 1 to 3, wherein the shape of the substrate holding part is convex upward.   The flattening apparatus according to claim 1, wherein the second region is a region having a predetermined width from an outer periphery of the substrate.   The flattening device according to claim 5, wherein the predetermined width is a width of 3 mm or less.   The planarization according to any one of claims 1 to 6, wherein the first region is a region where a pattern is already formed, and the second region is a region where a pattern is not formed. apparatus.   The flattening apparatus according to any one of claims 1 to 7, wherein a composition is disposed on the entire surface of the substrate to flatten the composition on the first region. In a planarization method for planarizing a composition on a substrate using a mold,
A step of separating the composition and the mold after the composition is flattened by contacting the composition with the mold disposed on the substrate,
The mold holding unit that holds the mold has a holding surface that holds an area outside the area including the center position of the mold,
The holding surface has a shape in which a position is increased toward an outer periphery of the mold holding unit,
In the step, the mold held by the holding surface is brought into contact with the composition on the first region including the center position of the substrate, and is separated from the composition on the second region outside the first region of the substrate. Flattening the composition on the first region in a state where the composition is formed, and then separating the mold from the composition on the first region. Flattening the composition of the substrate using the flattening method according to claim 9;
Treating a substrate having a planarized composition, and producing an article from the treated substrate.

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