JP2021005684A - Forming method and article manufacturing method - Google Patents

Abstract

To provide an advantageous technique for accurately forming a plurality of pattern layers on a member.SOLUTION: A forming method of forming a plurality of pattern layers composed of an imprint material on a member by applying an imprint process of molding the imprint material on the member with a mold includes a first forming step of forming a first pattern layer on the member, a measurement step of measuring relative positional deviation between the first pattern layer and a mark formed on the member, and a second forming step of forming a second pattern layer on the first pattern layer by shifting the mark with respect to the mark on the basis of the relative positional deviation measured in the measurement step.SELECTED DRAWING: Figure 6

Description

The present invention relates to a method for forming a plurality of pattern layers on a member and a method for manufacturing an article.

An imprinting apparatus for molding an imprinting material on a substrate (on a member) using a mold is attracting attention as one of mass production lithography apparatus such as a semiconductor device. The imprint device cures the imprint material in a state where the mold and the imprint material on the substrate are in contact with each other, and peels the mold from the cured imprint material to form unevenness composed of the imprint material. The pattern layer can be formed on the substrate. Patent Document 1 describes a method of accurately aligning a mold and a substrate in an imprinting apparatus.

JP-A-2018-61061

In the manufacture of semiconductor devices and the like, an imprint device may be used to superimpose and form a plurality of pattern layers made of an imprint material on a substrate. For example, when the second pattern layer is formed by superimposing the second pattern layer on the first pattern layer, alignment is performed with respect to the substrate, but if there is a relative misalignment between the first pattern layer and the substrate, It may be difficult to accurately form the second pattern layer on the first pattern layer.

Therefore, an object of the present invention is to provide an advantageous technique for accurately forming a plurality of pattern layers on a member.

In order to achieve the above object, the forming method as one aspect of the present invention applies an imprint process of molding an imprint material on a member with a mold to form a plurality of pattern layers composed of the imprint material. In the forming method of forming on the member, the relative positional deviation between the first forming step of forming the first pattern layer on the member and the mark formed on the first pattern layer and the member is measured. Includes a measurement step and a second forming step of shifting the second pattern layer with respect to the mark and forming it on the first pattern layer based on the relative positional deviation measured in the measurement step. It is characterized by.

Further objects or other aspects of the invention will be manifested in the preferred embodiments described below with reference to the accompanying drawings.

According to the present invention, for example, it is possible to provide an advantageous technique for accurately forming a plurality of pattern layers on a member.

Schematic diagram showing the configuration of the imprint device The figure which shows each process of the imprint process Diagram showing a typical alignment between a mold and a substrate Diagram to illustrate the distortion that occurs in the pattern layer Diagram showing typical double patterning Flowchart showing pattern formation method The figure for demonstrating each process of the pattern formation method The figure which shows the manufacturing method of an article

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiment, not all of the plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Further, in the attached drawings, the same or similar configurations are designated by the same reference numbers, and duplicate description is omitted.

In the following description, an example of forming a pattern layer made of an imprint material on a member by using an imprint device will be described. When a semiconductor device or the like is manufactured by using an imprint device, a substrate such as a semiconductor wafer can be used as a member on which a pattern layer is formed. Further, when a replica mold is produced using an imprint device, a blank mold made of quartz or the like can be used as a member on which the pattern layer is formed. Hereinafter, an example in which a substrate is used as a member on which a pattern layer is formed will be described.

The imprint device is a device that forms a pattern of a cured product to which the uneven pattern of the mold is transferred by bringing the imprint material supplied on the substrate into contact with the mold and applying energy for curing to the imprint material. Is. For example, an imprinting apparatus supplies an imprint material onto a substrate and cures the imprint material in a state where a mold having an uneven pattern is brought into contact with the imprint material on the substrate. Then, the pattern layer of the imprint material can be formed on the substrate by widening the distance between the mold and the substrate and peeling (releasing) the mold from the cured imprint material. Such a series of processes is called "imprint process" and is performed for each of a plurality of shot regions on the substrate.

As the imprint material, a curable composition (sometimes referred to as an uncured resin) that cures when energy for curing is applied is used. Electromagnetic waves, heat, etc. are used as the energy for curing. The electromagnetic wave is, for example, light such as infrared rays, visible rays, and ultraviolet rays whose wavelength is selected from the range of 10 nm or more and 1 mm or less.

The curable composition is a composition that is cured by irradiation with light or by heating. Of these, the photocurable composition that is cured by light may contain at least a polysynthetic compound and a photopolymerization initiator, and may contain a non-heavy synthetic compound or a solvent, if necessary. The non-heavy synthetic compound is at least one selected from the group of sensitizers, hydrogen donors, internal release mold release agents, surfactants, antioxidants, polymer components and the like.

The imprint material is applied in the form of a film on the substrate by a spin coater or a slit coater. Alternatively, the liquid injection head may be applied on the substrate in the form of droplets or in the form of islands or films formed by connecting a plurality of droplets. The viscosity of the imprint material (viscosity at 25 ° C.) is, for example, 1 mPa · s or more and 100 mPa · s or less.

[Configuration of imprint device]
The configuration of the imprinting apparatus 1 of the first embodiment according to the present invention will be described. FIG. 1 is a schematic view showing the configuration of the imprinting apparatus 1 of the present embodiment. In the following description, the direction parallel to the optical axis of the light applied to the mold 3 is defined as the Z direction, and the directions orthogonal to each other in the plane perpendicular to the Z direction are defined as the X direction and the Y direction.

The imprint device 1 includes, for example, a curing unit 2, an imprint head 4, a substrate stage 6, a supply unit 7, a detection unit 13, a first measurement unit 8, a second measurement unit 9, and a control unit. 10 and can be included. The control unit 10 is composed of, for example, a computer having a CPU, a memory, or the like, and controls each unit of the imprint device 1 (controls the imprint process). Here, the imprint head 4 is provided on the bridge surface plate 18 supported by the base surface plate 15 via the support columns 17, and the substrate stage 6 is provided so as to be movable on the base surface plate 15. .. Further, the imprint device 1 is provided with a vibration isolator 16 for reducing the vibration transmitted from the floor on which the imprint device 1 is installed to the base surface plate 15.

The mold 3 is usually made of a material capable of transmitting ultraviolet rays such as quartz, and a part of the area (pattern area, mesa area) protruding toward the substrate on the surface on the substrate side is on the substrate. An uneven pattern to be transferred to the imprint material is formed. Further, as the substrate 5, glass, ceramics, metal, semiconductor, resin, or the like is used, and if necessary, a member made of a material different from the substrate may be formed on the surface thereof. Specific examples of the substrate 5 include a silicon wafer, a compound semiconductor wafer, and quartz glass. Further, before applying the imprint material, an adhesion layer may be provided, if necessary, in order to improve the adhesion between the imprint material and the substrate.

The cured portion 2 (irradiated portion) receives light (for example, ultraviolet rays) from the imprint material on the substrate through the mold 3 in a state where the mold 3 and the imprint material on the substrate are in contact with each other during the imprint process. The imprint material is cured by irradiating with. The cured portion 2 may include, for example, a light source and an optical element for adjusting the light emitted from the light source to light suitable for imprint processing. The imprint device 1 of the first embodiment is configured such that the light 2a emitted from the cured portion 2 is reflected by the mirror 19 and irradiates the imprint material on the substrate.

The imprint head 4 may include a mold chuck that holds the mold 3 conveyed by the mold transfer unit 11 and a mold drive unit that is configured to be able to change the position and inclination of the mold 3 held by the mold chuck. The mold drive unit may be composed of, for example, a Z drive mechanism that drives the mold 3 in the Z direction so as to press the mold 3 against the imprint material on the substrate, a tilt drive mechanism that tilts the mold 3, and the like.

The substrate stage 6 is configured to hold the substrate 5 and be movable on the base platen 15 in the XY directions. The substrate stage 6 may include, for example, a substrate chuck that holds the substrate 5 transported by the substrate transport unit 12, and a substrate drive unit that is configured to be able to change the position and inclination of the substrate 5 held by the substrate chuck. .. The substrate drive unit may be composed of, for example, a drive mechanism that drives the substrate 5 in the XY direction, the Z direction, and the θ direction (rotational direction around the Z axis), a tilt drive mechanism that tilts the substrate 5, and the like.

Here, in the case of the present embodiment, the operation of bringing the mold 3 into contact with the imprint material on the substrate can be performed by driving the mold 3 in the Z direction with the imprint head 4. However, the present invention is not limited to this, and for example, the substrate 5 may be driven in the Z direction on the substrate stage 6, or the mold 3 and the substrate 5 may be relatively connected to each other on both the imprint head 4 and the substrate stage 6. It may be carried out by driving in the Z direction.

The detection unit 13 includes, for example, a TTM (Through The Mold) scope that detects a relative positional deviation between a mark provided on the mold 3 and a mark provided on the substrate 5. As a result, the control unit 10 aligns (aligns) the mold 3 with the substrate 5 based on the relative positional deviation between the mark of the mold 3 and the mark of the substrate 5 detected by the detection unit 13 (TTM scope). It can be carried out. Further, the supply unit 7 supplies the imprint material 14 (for example, uncured resin) on the substrate. In the case of the present embodiment, an ultraviolet curable resin having a property of being cured by irradiation with ultraviolet rays is used as the imprint material 14.

The first measuring unit 8 measures the height and inclination of the substrate 5. For example, the first measurement unit 8 may include a laser interferometer that irradiates the substrate 5 with light (laser light) and detects the position (Z direction) of the portion of the substrate 5 irradiated with the light. The first measuring unit 8 can measure the height and inclination of the substrate 5 by moving the substrate 5 on the substrate stage 6 and detecting the position (Z direction) at each of a plurality of locations on the substrate 5. it can.

The second measuring unit 9 measures the height and inclination of the mold 3 (pattern region). For example, the second measuring unit 9 may include a laser interferometer that irradiates the mold 3 with light (laser light) and detects the position (Z direction) of the portion of the mold 3 irradiated with the light. The second measuring unit 9 is provided on the substrate stage 6, and while moving by the substrate stage 6, the height and inclination of the mold 3 are determined by detecting the position (Z direction) at each of a plurality of locations on the mold 3. Can be measured.

[Imprint processing]
The imprint process will be described with reference to FIG. FIG. 2 is a diagram showing each step of the imprint process.
First, the mold 3 is conveyed to the imprint head 4 by the mold transfer portion 11, and is held by the imprint head 4 (mold holding portion) by a vacuum chuck or the like. Further, the substrate 5 is transported to the substrate stage 6 by the substrate transport unit 12, and is held by the substrate stage 6 (board holding portion) by a vacuum chuck or the like. After the mold 3 and the substrate 5 are conveyed, the height and inclination of the substrate 5 are measured by the first measuring unit 8, and the height and inclination of the mold 3 are measured by the second measuring unit 9. The information obtained by these measuring units determines the relative drive amount (Z direction) between the mold 3 and the substrate 5 when the mold 3 and the imprint material on the substrate are brought into contact with each other, and the mold 3 and the substrate 5 are used. It can be used to determine the relative tilt amount to make and parallel.

Next, the substrate 5 is moved by the substrate stage 6 so that the shot region to be imprinted (hereinafter referred to as the target shot region) among the plurality of shot regions on the substrate 5 is arranged below the supply unit 7. .. Then, the supply unit 7 supplies the droplets of the imprint material 14 onto the target shot region by an inkjet method or the like (FIG. 2A). The arrangement and number of droplets of the imprint material 14 to be supplied on the target shot area can be determined in advance based on the pattern shape and film thickness of the pattern layer of the imprint material to be formed on the target shot area. .. As the film thickness of the pattern layer, the residual film thickness (RLT; Residual Layer Thickness) may be applied. The residual film thickness is the thickness of the imprint material 14 between the bottom surface of the concave portion of the uneven pattern layer made of the imprint material and the substrate 5.

After the imprint material 14 is supplied onto the target shot region, the substrate 5 is moved by the substrate stage 6 so that the target shot region is arranged below the mold 3 (FIG. 2B). Then, the mold 3 and the substrate 5 are relatively driven in the Z direction so that the distance between them is narrowed so that the mold 3 and the imprint material 14 on the target shot region are brought into contact with each other, and the mold 3 and the substrate 5 (target shot region) are brought into contact with each other. ) (Fig. 2 (c)).

After the alignment is completed and the imprint material 14 is filled with the uneven pattern of the mold 3, the imprint material 14 is exposed to light by the cured portion 2 while the mold 3 and the imprint material 14 are in contact with each other. Irradiation is performed to cure the imprint material 14. Then, the mold 3 is peeled off from the cured imprint material 14 by relatively driving the mold 3 and the substrate 5 in the Z direction so that the distance between them is widened (FIG. 2D). As a result, the uneven pattern of the mold 3 is transferred to the imprint material 14 on the target shot region, and the pattern layer of the imprint material 14 can be formed on the target shot region. Such an imprint process is performed on each of the plurality of shot regions on the substrate 5.

[About alignment]
A typical alignment between the mold 3 and the substrate 5 (target shot region) will be described with reference to FIG. The alignment between the mold 3 and the substrate 5 is, for example, an alignment in which the mold 3 and the imprint material 14 on the substrate are not in contact with each other and a state in which the mold 3 and the imprint material on the substrate are in contact with each other. Alignment and can be included. FIG. 3 is a diagram for explaining alignment in a state where the mold 3 and the imprint material 14 on the substrate are in contact (contact state), and is a part of the mold 3 and the substrate 5 in FIG. 2C. Is cut out and shown. In a typical alignment in a contact state, the relative positional deviation (XY direction) between the mark 21 formed on the mold 3 and the mark 22 formed on the substrate 5 is the target value based on the detection result of the detection unit 13. The mold 3 and the substrate 5 can be driven so as to be. Here, an example in which the position of the mark 21 formed on the mold 3 and the position of the mark 22 formed on the substrate 5 are matched in the XY directions (that is, the target value is set to zero) will be described.

Hereinafter, the mark 21 formed on the mold 3 may be referred to as a “mold mark 21”, and the mark 22 formed on the substrate 5 may be referred to as a “board mark 22”. The mold mark 21 is formed in a concavo-convex shape, for example, and can be formed at the same time when forming a concavo-convex pattern as a device pattern (circuit pattern). Further, the substrate mark 22 is formed in, for example, an uneven shape, and is formed on the substrate 5 in the previous step. The substrate mark 22 may be formed at the same time when the base pattern is formed. Further, in the following, in order to make the explanation easier to understand, an example in which the mold mark 21 and the substrate mark 22 are provided one by one and the mold 3 and the substrate 5 are aligned in the X direction will be described, but the description is limited thereto. is not. For example, the mold marks 21 are provided at a plurality of positions of the mold 3 (for example, the four corners of the rectangular pattern region), and the substrate marks 22 are a plurality of substrates 5 so as to correspond to the positions of the mold marks 21 (XY directions). It may be provided at a location (for example, four corners of a rectangular shot area). In this case, by detecting the relative positional deviation between the mold mark 21 and the substrate mark 22 at each of the plurality of locations by the detection unit 13, the relative positions of the mold 3 and the substrate 5 in the XY direction are added to the θ direction (Z). It is also possible to correct the relative position (rotation direction around the axis) and the shape difference (magnification, etc.).

The mold 3 and the substrate 5 are arranged so that the mold mark 21 and the substrate mark 22 are within the field of view of the detection unit 13 (TTM scope) before the mold 3 and the imprint material 14 on the substrate are brought into contact with each other. .. Then, the mold 3 and the substrate 5 are relatively driven in the Z direction so that the distance between them is narrowed, so that the mold 3 and the imprint material 14 on the substrate are brought into contact with each other.

FIG. 3A shows a state in which the mold 3 and the imprint material 14 on the substrate are in contact with each other. In the state shown in FIG. 3A, the detection unit 13 detects the relative positional deviation 23 between the mold mark 21 and the substrate mark 22 by performing known image processing on the image obtained by the TTM scope. be able to. In the example shown in FIG. 3A, since the substrate mark 22 is displaced in the + X direction with respect to the mold mark 21, the substrate stage 6 drives the substrate 5 in the −X direction. That is, as shown in FIG. 3B, the mold 3 and the substrate 5 are aligned so that the position of the mold mark 21 and the position of the substrate mark 22 coincide with each other in the X direction. After the alignment is completed, the imprint material 14 is irradiated with light to cure the imprint material 14, and the mold 3 is peeled from the cured imprint material 14 as shown in FIG. 3 (c). As a result, the pattern layer of the imprint material 14 can be formed on the substrate.

Here, in the alignment between the mold 3 and the substrate 5, when the mold 3 and the substrate 5 are driven in a state where the mold 3 and the imprint material 14 on the substrate are in contact with each other, the imprint material 14 formed on the substrate is driven. Distortion can occur in the pattern layer of. This will be described with reference to FIG. Normally, the mold 3 is held by the imprint head 4 outside the pattern area (a peripheral area surrounding the pattern area). This is because the pattern region of the mold 3 needs to transmit light that cures the imprint material. Therefore, when the mold 3 and the substrate 5 are relatively driven as shown in FIG. 3 (c) with the mold 3 and the imprint material 14 on the substrate in contact with each other, as shown by the arrow in FIG. 4 (a), A tensile force is generated in the opposite direction between the central portion and the peripheral portion of the mold 3 (pattern region). As a result, as shown in FIG. 4B, bow-shaped distortion occurs in the entire pattern region of the mold 3, and as a result, the pattern layer of the imprint material 14 formed on the substrate is also distorted. Can occur.

The likelihood of distortion may depend on the following cases. For example, the thinner the residual film thickness (RLT), the greater the resistance (that is, the driving force) when the mold 3 and the substrate 5 are relatively driven via the imprint material 14, and distortion is likely to occur. The residual film thickness may depend on the amount of the imprint material 14 supplied onto the substrate. Further, the larger the unevenness of the substrate 5, the larger the driving force when the mold 3 and the substrate 5 are relatively driven via the imprint material 14, and the distortion is likely to occur. Similarly, for the base pattern and the pattern of the mold 3 already formed on the substrate 5 (shot region), when the density of the pattern is high, that is, when many fine patterns are arranged, the driving force is large. Therefore, distortion is likely to occur. As will be described later, in the embodiment of the present invention, control is performed in consideration of such distortion.

[About double patterning]
In the embodiment of the present invention, double patterning is adopted. The double patterning is a method of forming a plurality of pattern layers made of an imprint material on a substrate in order to form a pattern having a narrow line width exceeding the limit of patterning on the substrate.

FIG. 5 is a diagram showing a typical double patterning. In a typical double patterning, first, as shown in FIGS. 5 (a) to 5 (b), a first pattern layer 14a made of the imprint material 14 is formed on the substrate. Specifically, as shown in FIG. 5A, the positions of the mold mark 21a and the substrate mark 22 are aligned with each other in a state where the first mold 3a and the imprint material 14 on the substrate are in contact with each other. , Alignment (relative drive) between the first mold 3a and the substrate 5 is performed. Then, after the imprint material 14 is cured, the first mold 3a is peeled from the cured imprint material 14 as shown in FIG. 5 (b). As a result, the first pattern layer 14a made of the imprint material can be formed on the substrate.

Next, as shown in FIGS. 5C to 5D, the second pattern layer 14b made of the imprint material 14 is superposed on the first pattern layer 14a formed on the substrate. .. Specifically, as shown in FIG. 5C, the positions of the mold mark 21b and the substrate mark 22 are located in a state where the second mold 3b and the imprint material 14 on the first pattern layer 14a are in contact with each other. The second mold 3b and the substrate 5 are aligned (relatively driven) so as to match. Then, after the imprint material 14 is cured, the second mold 3b is peeled from the cured imprint material 14 as shown in FIG. 5 (d). As a result, the second pattern layer 14b made of the imprint material can be formed by superimposing it on the first pattern layer 14a. In actual device manufacturing, the first pattern layer 14a may be formed by imprint processing, and then a protective film may be applied or etched, and then the second pattern layer 14b may be formed by imprint processing. .. Similarly, in this case, the basic part of the present invention is the same, and the deviation after processing such as etching may be the deviation of the first pattern layer 14a.

Here, in the first pattern layer 14a, it is often required to form a very fine pattern, which is also called a critical layer, with high accuracy, and in order to satisfy the requirement, the residual film thickness (RLT) is thinned. There is a need to. However, if the residual film thickness is thin, the first pattern layer 14a is distorted due to the relative drive between the mold 3 and the substrate 5 in a state where the mold 3 and the imprint material 14 on the substrate are in contact with each other. There's a problem. On the other hand, in the second pattern layer 14b, the pattern miniaturization and accuracy are not required as compared with the first pattern layer 14a, so that the residual film thickness (RLT) can be made thicker than that of the first pattern layer 14a. Further, it is often desirable that the second pattern layer 14b is positioned more accurately with respect to the first pattern layer 14a than with respect to the substrate 5.

Hereinafter, embodiments of the pattern forming method according to the present invention, which can reduce the distortion generated in the first pattern layer 14a and accurately form the second pattern layer 14b on the first pattern layer 14a, will be described. ..

<First Embodiment>
The pattern forming method of the first embodiment according to the present invention will be described with reference to FIGS. 6 to 7. In the pattern forming method of the present embodiment, the above-mentioned double patterning is adopted. FIG. 6 is a flowchart showing a pattern forming method of the present embodiment. Each process of the flowchart shown in FIG. 6 can be controlled by the control unit 10. Further, FIG. 7 is a diagram for explaining each step of the pattern forming method of the present embodiment, and the mold 3 (first mold 3a, second mold 3b) and the substrate 5 are shown.

In S11, as shown in FIGS. 7A to 7B, the first mold 3a is used to form the first pattern layer 14a made of the imprint material 14 on the substrate (first forming step). .. The first pattern layer 14a is a critical layer, and it is required to form a very fine pattern on the substrate with high accuracy. That is, the first pattern layer 14a is required to have high accuracy (pattern formation accuracy) required for pattern formation and to be formed so as not to cause distortion.

It is known that the distortion correlates with the driving force when the mold 3 and the substrate 5 are relatively driven via the imprint material 14. Therefore, it is preferable that the driving force (for example, the driving force of the substrate stage 6) is within a range that satisfies the pattern formation accuracy. Specifically, the higher the pattern formation accuracy, the thinner the residual film thickness (RLT), so that it is difficult to drive the mold 3 and the substrate 5 relative to each other via the imprint material 14, and the driving force increases. However, if the driving force is increased, distortion is likely to occur accordingly. Therefore, it is preferable to change (switch) the control content of the alignment between the first mold 3a and the substrate 5 according to the pattern formation accuracy for the first pattern layer 14a.

For example, as the alignment control content, the upper limit value of the driving force when the mold 3 and the substrate 5 are relatively driven in a state where the mold 3 and the imprint material 14 on the substrate are in contact (contact state) is set as a pattern. It may be changed according to the formation accuracy. Specifically, the higher the pattern formation accuracy, the smaller the upper limit of the driving force. In this case, since the relative drive between the mold 3 and the substrate 5 via the imprint material 14 can be performed gently, the distortion generated in the first pattern layer can be reduced. Further, depending on the pattern formation accuracy (for example, when the pattern formation accuracy is equal to or higher than the threshold value), even if the alignment control content is changed so that the mold 3 and the substrate 5 are not driven relative to each other in the contact state. Good.

The pattern formation accuracy can be determined (determined) based on, for example, information (for example, design data) regarding the film thickness of the first pattern layer 14a to be formed on the substrate. For example, the film thickness of the first pattern layer 14a includes the residual film thickness (RLT), and it can be determined that the thinner the residual film thickness required for the first pattern layer 14a, the higher the pattern formation accuracy. In this case, the alignment control content can be changed so that the upper limit of the driving force becomes smaller as the residual film thickness required for the first pattern layer 14a becomes thinner. Alternatively, when the residual film thickness required for the first pattern layer 14a is equal to or less than the threshold value, the alignment control content can be changed so that the relative drive between the mold 3 and the substrate 5 in the contact state is not performed.

Further, the pattern formation accuracy can be determined based on, for example, information (for example, design data) regarding the amount of the imprint material 14 to be supplied on the substrate by the supply unit 7. For example, it can be determined that the smaller the amount of the imprint material 14 supplied on the substrate when the first pattern layer 14a is formed, the higher the pattern forming accuracy. In this case, the alignment control content can be changed so that the smaller the amount of the imprint material 14 supplied on the substrate, the smaller the upper limit of the driving force. Alternatively, when the amount of the imprint material 14 supplied on the substrate is equal to or less than the threshold value, the alignment control content can be changed so that the mold 3 and the substrate 5 are not driven relative to each other in the contact state.

Further, the pattern formation accuracy can be determined based on, for example, information (for example, design data) regarding the shape of the pattern to be formed on the first pattern layer 14a. For example, it can be determined that the higher the density of the pattern to be formed on the first pattern layer 14a (that is, the smaller the line width of the pattern), the higher the pattern forming accuracy. In this case, the alignment control content can be changed so that the higher the density of the pattern to be formed on the first pattern layer 14a, the smaller the upper limit of the driving force. Alternatively, when the density of the pattern to be formed on the first pattern layer 14a is equal to or higher than the threshold value, the alignment control content can be changed so that the mold 3 and the substrate 5 are not driven relative to each other in the contact state.

Further, the pattern formation accuracy can be determined, for example, based on information (for example, measurement results) regarding the shape of the base pattern already formed on the substrate 5. For example, the higher the density of the base pattern or the smaller the line width of the base pattern, the more likely it is that distortion occurs in the first pattern layer 14a, so that it can be determined that the pattern formation accuracy is high. In this case, the alignment control content can be changed so that the higher the density of the base pattern or the smaller the line width of the base pattern, the smaller the upper limit of the driving force. Alternatively, when the density of the base pattern is equal to or higher than the threshold value, or when the line width of the base pattern is equal to or lower than the threshold value, the alignment control content is changed so that the mold 3 and the substrate 5 are not driven relative to each other in the contact state. Can be done.

Here, in the case of the present embodiment, since the first pattern layer 14a is a critical layer, high pattern formation accuracy is required so that distortion does not occur. Further, the first pattern layer 14a is often formed on a blank substrate on which only the substrate mark 22 is formed, and the requirement for overlay accuracy with respect to the substrate 5 is not high. Therefore, in the formation of the first pattern layer 14a (S11) in the present embodiment, the alignment control content can be changed so that the relative drive between the mold and the substrate 5 in the contact state is not performed. In this case, the first pattern layer 14a can be formed on the substrate so as to satisfy the pattern forming accuracy, but the pattern formed on the first pattern layer 14a and the substrate 5 (board mark 22) are relative to each other in the XY direction. Misalignment can occur. When the first mold 3a and the imprint material on the substrate are not in contact with each other, the mold 3 and the substrate 5 may be aligned based on the detection result of the detection unit 13.

Returning to the flowchart shown in FIG. 6, in S12, as shown in FIG. 7C, the relative of the first pattern layer 14a (that is, the pattern formed on the first pattern layer 14a) and the substrate mark 22 in the XY direction. Measure the misalignment (measurement process). Specifically, by measuring the positional relationship between the reference point (feature point) of the pattern in the first pattern layer 14a and the substrate mark 22, the difference between the measured value 24 and the design value 25 is determined by the first pattern layer. It can be obtained as a relative positional deviation 26 between 14a and the substrate mark 22. The relative positional deviation 26 (the positional relationship) may be detected by, for example, the detection unit 13, or may be measured by a dedicated scope (measurement unit) provided inside the imprint device 1. Further, the relative positional deviation may be measured by a measuring device provided outside the imprint device 1. In this case, an interface for inputting the relative positional deviation may be provided in the imprint device 1 (control unit 10).

In S13, as shown in FIGS. 7 (d) to 7 (e), the second pattern layer 14b made of the imprint material 14 is formed on the first pattern layer 14a by using the second mold 3b. (Second forming step). At this time, the second pattern layer 14b is formed by shifting the substrate 5 (board mark 22) based on the relative positional deviation 26 measured in S12. Specifically, the second pattern layer 14b is formed by shifting the second pattern layer 14b with respect to the substrate mark 22 by the relative positional deviation of 26 minutes measured in S12. As a result, the second pattern layer 14b can be accurately formed on the first pattern layer 14a in which the relative position shift with respect to the substrate 5 (board mark 22) occurs. That is, the overlay accuracy of the first pattern layer 14a and the second pattern layer 14b can be kept within an allowable range.

As described above, in the present embodiment, the relative positional deviation between the first pattern layer 14a formed on the substrate and the substrate mark 22 is measured using the first mold 3a, and the substrate is based on the relative positional deviation. The second pattern layer 14b is formed by shifting the mark 22 with respect to the mark 22. Further, when the first pattern layer 14a is formed on the substrate, the control content of the alignment between the mold 3 and the substrate 5 can be changed according to the pattern formation accuracy. As a result, the distortion generated in the first pattern layer 14a can be reduced, and the second pattern layer 14b can be accurately formed on the first pattern layer 14a.

<Second Embodiment>
In the first embodiment, an example in which a substrate 5 (for example, a semiconductor wafer) is used as a member forming a plurality of pattern layers has been described, but the present invention is not limited thereto. For example, when producing a replica mold using the imprint device 1 described above, a blank mold may be used as the member. In this case, only the mark (board mark 22) can be formed on the blank mold.

Further, in the first embodiment, in the step of S12, by detecting the pattern (reference portion) formed on the first pattern layer 14a and the substrate mark 22, the relative between the first pattern layer 14a and the substrate mark 22 is detected. An example of measuring the misalignment has been described. However, the present invention is not limited to this, and for example, by forming a mark on the first pattern layer 14a and detecting the mark formed on the first pattern layer 14a and the substrate mark 22, the first pattern layer 14a and the substrate mark 22 can be formed. The relative misalignment of may be measured. For example, when the first pattern layer 14a is formed, the mold mark 21 is arranged in the mold 3 so that the imprint material 14 is filled in the mold mark 21 and the mold mark 21 is transferred to the first pattern layer 14a. Can be done. By measuring the positional relationship between the mold mark 21 transferred to the first pattern layer 14 and the substrate mark 22 in this way, a relative positional deviation between the first pattern layer 14a and the substrate mark 22 can be obtained.

Further, when the first pattern layer 14a is also formed on the substrate mark 22, the substrate mark 22 may not be detected (invisible) by the detection unit 13 when the second pattern layer 14b is formed. In this case, in addition to the substrate mark 22 for measuring the relative positional deviation with respect to the first pattern layer 14a, a dedicated mark for use in alignment when forming the second pattern layer 14b is formed on the substrate. It is good to keep it. That is, it is preferable that the substrate mark 22 for measuring the relative positional deviation and the dedicated mark for using the alignment at the time of forming the second pattern layer 14b are simultaneously and in advance formed on the substrate. In this case, the second pattern layer 14b can be accurately formed on the first pattern layer 14a even if different marks are used as a reference between the measurement of the relative positional deviation and the formation of the second pattern layer 14b.

<Embodiment of manufacturing method of article>
The method for manufacturing an article according to the embodiment of the present invention is suitable for producing an article such as a microdevice such as a semiconductor device or an element having a fine structure. The method for manufacturing an article of the present embodiment includes a step of forming a pattern on an imprint material supplied (coated) to a substrate by using the above-mentioned imprint device (imprint method), and a pattern is formed by such a step. Includes the process of processing the substrate. Further, such a manufacturing method includes other well-known steps (oxidation, film formation, vapor deposition, doping, flattening, etching, resist peeling, dicing, bonding, packaging, etc.). The method for producing an article of the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article as compared with the conventional method.

The pattern of the cured product formed by using the imprint device is used permanently for at least a part of various articles or temporarily when producing various articles. The article is an electric circuit element, an optical element, a MEMS, a recording element, a sensor, a mold, or the like. Examples of the electric circuit element include volatile or non-volatile semiconductor memories such as DRAM, SRAM, flash memory, and MRAM, and semiconductor elements such as LSI, CCD, image sensor, and FPGA. Examples of the mold include a mold for imprinting.

The pattern of the cured product is used as it is as a constituent member of at least a part of the above-mentioned article, or is temporarily used as a resist mask. The resist mask is removed after etching or ion implantation in the substrate processing process.

Next, a specific manufacturing method of the article will be described. As shown in FIG. 8A, a substrate 1z such as a silicon wafer on which a work material 2z such as an insulator is formed on the surface is prepared, and subsequently, a substrate 1z such as a silicon wafer is introduced into the surface of the work material 2z by an inkjet method or the like. The printing material 3z is applied. Here, a state in which a plurality of droplet-shaped imprint materials 3z are applied onto the substrate is shown.

As shown in FIG. 8B, the imprint mold 4z is opposed to the imprint material 3z on the substrate with the side on which the uneven pattern is formed facing. As shown in FIG. 8C, the substrate 1z to which the imprint material 3z is applied is brought into contact with the mold 4z, and pressure is applied. The imprint material 3z is filled in the gap between the mold 4z and the work material 2z. When light is irradiated through the mold 4z as energy for curing in this state, the imprint material 3z is cured.

As shown in FIG. 8D, when the mold 4z and the substrate 1z are separated from each other after the imprint material 3z is cured, a pattern of the cured product of the imprint material 3z is formed on the substrate 1z. The pattern of the cured product has a shape in which the concave portion of the mold corresponds to the convex portion of the cured product and the convex portion of the mold corresponds to the concave portion of the cured product, that is, the uneven pattern of the mold 4z is transferred to the imprint material 3z. It will have been done.

As shown in FIG. 8 (e), when etching is performed using the pattern of the cured product as an etching resistant mask, the portion of the surface of the work material 2z that has no cured product or remains thin is removed, and the groove 5z is formed. Become. As shown in FIG. 8 (f), when the pattern of the cured product is removed, an article in which the groove 5z is formed on the surface of the work material 2z can be obtained. Although the pattern of the cured product is removed here, it may be used as a film for interlayer insulation contained in a semiconductor element or the like, that is, as a constituent member of an article, without being removed even after processing.

The invention is not limited to the above embodiments, and various modifications and modifications can be made without departing from the spirit and scope of the invention. Therefore, a claim is attached to make the scope of the invention public.

1: Imprint device, 2: Curing part, 3: Mold, 4: Imprint head, 5: Substrate, 6: Substrate stage, 7: Supply unit, 10: Control unit, 13: Detection unit

Claims (13)

It is a forming method of forming a plurality of pattern layers composed of an imprint material on the member by applying an imprint process of molding the imprint material on the member with a mold.
The first forming step of forming the first pattern layer on the member, and
A measurement step for measuring the relative positional deviation between the first pattern layer and the mark formed on the member, and
A second forming step of shifting the second pattern layer with respect to the mark and forming it on the first pattern layer based on the relative positional deviation measured in the measuring step.
A forming method comprising. The forming method according to claim 1, wherein the control content of the alignment between the mold and the member is different between the first forming step and the second forming step. The first forming step according to claim 1 or 2, wherein the first forming step does not include alignment between the mold and the member in a state where the mold and the imprint material on the member are in contact with each other. Forming method. One of claims 1 to 3, wherein the first forming step includes alignment of the mold and the member in a state where the mold and the imprint material on the member are not in contact with each other. The forming method according to item 1. Any of claims 1 to 4, wherein the second forming step includes alignment of the mold and the member in a state where the mold and the imprint material on the member are in contact with each other. The forming method according to item 1. The forming method according to any one of claims 1 to 5, wherein the first pattern layer has a thinner residual film thickness than the second pattern layer. In the first forming step, when the mold and the member are relatively driven in a state where the mold and the imprint material on the member are in contact with each other according to the pattern forming accuracy of the first pattern layer. The forming method according to claim 1, wherein the upper limit value of the driving force is changed. In the first forming step, relative driving between the mold and the member is performed in a state where the mold and the imprint material on the member are in contact with each other according to the pattern forming accuracy of the first pattern layer. The forming method according to claim 1, wherein there is no such thing. The forming method according to claim 7 or 8, wherein the pattern forming accuracy is determined based on the information regarding the residual film thickness of the first pattern layer. Any of claims 7 to 9, wherein the pattern forming accuracy is determined based on information about the amount of imprint material supplied onto the member to form the first pattern layer. The forming method according to item 1. The forming method according to any one of claims 7 to 10, wherein the pattern forming accuracy is determined based on information on the shape of the pattern formed on the first pattern layer. The forming method according to any one of claims 7 to 11, wherein the pattern forming accuracy is determined based on information on the shape of a pattern already formed on the member. A forming step of forming a pattern on a substrate by using the forming method according to any one of claims 1 to 12.
Including a processing step of processing the substrate on which a pattern is formed in the forming step.
A method for producing an article, which comprises producing an article from the substrate processed in the processing step.

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