JP2019016648A - Imprinting method, imprint apparatus, and article manufacturing method - Google Patents

Abstract

To provide an imprinting method which is advantageous for improving the degree of freedom of the supply position of an imprint material.SOLUTION: An imprint method in which an uncured imprint material R on a substrate W is molded with a mold M and cured to form a pattern of the cured imprint material R in a plurality of shot regions provided on the substrate W includes a first step of supplying an uncured imprint material R to one shot region among a plurality of shot regions on the substrate W while moving the substrate W in a first direction along the surface of the substrate W and a second step of supplying an uncured imprint material R to one shot area while moving the substrate W along the surface of the substrate W in a second direction orthogonal to the first direction.SELECTED DRAWING: Figure 4

Description

The present invention relates to an imprint method, an imprint apparatus, and an article manufacturing method.

  One of lithography methods for manufacturing articles such as semiconductor devices and liquid crystal display devices is an imprint method. The imprint method is a method of forming a fine pattern by bringing a mold into contact with an uncured imprint material supplied on a substrate. As a method of supplying uncured imprint material on a substrate, a method of supplying uncured imprint material of uniform thickness to a plurality of target areas (shot regions) of a substrate using a plurality of nozzles arranged in parallel (Patent Document 1).

JP 2007-2731979 A

  However, in the method of Patent Document 1, the degree of freedom such as the target supply position and supply amount in each shot region of a plurality of droplets of an uncured imprint material supplied to each of the plurality of shot regions can be limited. .

  An object of the present invention is to provide an imprint method that is advantageous for improving the degree of freedom of the supply position of an imprint material, for example.

  In order to solve the above problems, the present invention forms an uncured imprint material on a substrate with a mold and cures it, and forms a pattern of the cured imprint material on a plurality of shot regions provided on the substrate. A first step of supplying an uncured imprint material to one shot area among a plurality of shot areas on a substrate while moving the substrate in a first direction along the surface of the substrate. And a second step of supplying an uncured imprint material to one shot area while moving the substrate along a surface of the substrate and in a second direction orthogonal to the first direction. And

  According to the present invention, for example, it is possible to provide an imprint method that is advantageous for improving the degree of freedom of the supply position of the imprint material.

It is the schematic which shows the structure of the imprint apparatus using the imprint method which concerns on embodiment. The state when the imprint material protrudes from the mold end is shown. The case where the discharge of the imprint material by one part among several discharge ports is stopped is shown. A state in which the imprint material is supplied to the shot area using only one of the ejection units is shown. A state in which the imprint material is supplied to the shot region using only the other ejection unit is shown. 2 shows a discharge section having discharge ports arranged at predetermined intervals in the X direction and the Y direction. The discharge part which has the discharge port located in a line with L character is shown. The discharge part by which the discharge outlet was arrange | positioned diagonally so that X direction and Y direction might be crossed is shown.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In addition, in each drawing, the same reference number is attached | subjected about the same member thru | or element, and the overlapping description is abbreviate | omitted.
Embodiment

(Imprint device)
FIG. 1 is a schematic diagram showing a configuration of an imprint apparatus using an imprint method according to an embodiment of the present invention. Here, as an imprint apparatus using a photocuring method, an ultraviolet curable imprint apparatus that cures an uncured imprint material on a substrate by irradiation with ultraviolet rays was used. However, as a method for curing the imprint material, a method using light irradiation in another wavelength region or a method using other energy (for example, heat) may be used. In the following figure, the Z axis is taken in parallel to the optical axis of the ultraviolet rays irradiated to the imprint material on the substrate, and the X axis and the Y axis perpendicular to each other are taken in a plane perpendicular to the Z axis. ing.

  The imprint apparatus 1 includes a light irradiation unit 2, a mold holding unit 3, a substrate stage (substrate holding unit) 4, a supply unit (dispenser) 5, and a control unit 6. The light irradiation unit 2 irradiates the mold M with ultraviolet rays UV during the imprint process. Although not shown, the light irradiation unit 2 includes a light source and an illumination optical system that adjusts ultraviolet light UV emitted from the light source to light suitable for imprinting and irradiates the mold M. The light source may be a lamp such as a mercury lamp, but is not particularly limited as long as it is a light source that transmits light of a wavelength that transmits the mold M and cures an imprint material R described later. The illumination optical system may include a lens, a mirror, an aperture, or a shutter for switching between irradiation and light shielding. In this embodiment, the light irradiation unit 2 is installed in order to employ the photocuring method. However, for example, when the thermosetting method is employed, the light irradiation unit 2 is replaced with a thermosetting property. A heat source for curing the resin will be installed.

  The mold (mold) M has a polygonal shape (preferably a rectangle or a square) as an outer peripheral shape, and a pattern in which a concavo-convex pattern to be transferred such as a circuit pattern is formed in a three-dimensional manner on the surface with respect to the substrate W. Part P is included. The pattern size varies depending on the article to be manufactured, but a fine pattern includes a pattern of several tens of nanometers. The material of the mold M is preferably capable of transmitting ultraviolet UV and has a low coefficient of thermal expansion, and may be quartz, for example. Further, the mold M may have a cavity having a circular shape and a certain depth on the surface irradiated with the ultraviolet rays UV.

  The mold holding unit 3 corrects the shape of the mold M (pattern part P), which is not shown, but includes a mold chuck 31 that holds the mold M, a mold drive unit 32 that holds the mold chuck 31 movably. A magnification correction mechanism. The mold chuck 31 can hold the mold M by attracting the outer peripheral area of the irradiation surface of the mold M with the ultraviolet ray UV by a vacuum adsorption force or an electrostatic force. For example, when the mold chuck 31 holds the mold M by a vacuum suction force, the mold chuck 31 is connected to a vacuum pump (not shown) installed outside, and by appropriately adjusting the suction pressure by exhausting the vacuum pump, The adsorption power (holding power) can be adjusted.

  The mold driving unit 32 moves the mold M in each axial direction so as to selectively press or separate the mold M and the imprint material R on the substrate W. Examples of the power source that can be employed in the mold drive unit 32 include a linear motor and an air cylinder. In addition, the mold driving unit 32 can be composed of a plurality of driving systems such as a coarse driving system and a fine driving system in order to cope with high-precision positioning of the mold M. Further, the mold driving unit 32 is not only in the Z-axis direction but also in the X-axis direction, the Y-axis direction, or the θ (rotation around the Z-axis) direction, a tilt function for correcting the inclination of the mold M, and the like. There may also be a configuration having

  The pressing and pulling operations in the imprint apparatus 1 may be realized by moving the mold M in the Z-axis direction, but may be realized by moving the substrate stage 4 in the Z-axis direction. Alternatively, both of them may be moved relatively. The position of the mold M at the time of driving the mold driving section 32 is not shown, but can be measured by a position measuring section such as an optical displacement meter that measures the distance between the mold M and the substrate W. The magnification correction mechanism is installed on the mold M holding side of the mold chuck 31 and mechanically applies an external force or displacement to the side surface of the mold M to correct the shape of the mold M (pattern part P).

  Further, the mold chuck 31 and the mold driving unit 32 have an opening region 33 that allows the ultraviolet rays UV irradiated from the light irradiation unit 2 to pass toward the substrate W at the center (inner side) in the planar direction.

  The substrate (wafer) W is, for example, a single crystal silicon substrate, an SOI (Silicon on Insulator) substrate, or a glass substrate. A plurality of pattern formation regions on the substrate W (a pattern (hereinafter referred to as “substrate-side pattern” has already been formed in the previous process before being carried into the imprint apparatus 1) is formed by the pattern portion P. A pattern (a layer including a pattern) of the imprint material R is formed.

  The substrate stage 4 holds the substrate W in a movable manner, and performs, for example, alignment between the pattern portion P and the substrate side pattern when the mold M and the imprint material R on the substrate W are pressed. The substrate stage 4 mechanically holds the wafer chuck 41 that holds the substrate W by suction force, the auxiliary member 42 that is installed so as to surround the outer periphery of the substrate W, and moves in each axial direction. And a stage drive unit 43 that enables this.

  For example, the wafer chuck 41 holds the substrate W by supporting the substrate W with a plurality of pins having a uniform height and reducing the pressure other than the pins by evacuation. The auxiliary member 42 has a surface height equivalent to that of the substrate W placed on the wafer chuck 41 and is used to make the thickness of the resin pattern uniform at the outer peripheral edge of the substrate W.

  The stage drive unit 43 is a power source with little vibration during driving and at rest, and examples of the power source that can be adopted include a linear motor and a planar motor. The stage drive unit 43 can also be configured by a plurality of drive systems such as a coarse drive system and a fine drive system in each direction of the X axis and the Y axis. Furthermore, there may be a configuration having a drive system for position adjustment in the Z-axis direction, a position adjustment function of the substrate W in the θ direction, or a tilt function for correcting the tilt of the substrate W.

  Further, the substrate stage 4 includes a plurality of reference mirrors 44 corresponding to the X, Y, Z, ωx, ωy, and ωz directions on its side surface. On the other hand, the imprint apparatus 1 includes a plurality of laser interferometers (measurement units) 7 that measure the position of the substrate stage 4 by irradiating these reference mirrors 44 with a beam such as helium neon. In FIG. 1, only one set of the reference mirror 44 and the laser interferometer 7 is illustrated. The laser interferometer 7 measures the position of the substrate stage 4 in real time, and the control unit 6 described later executes positioning control of the substrate W (substrate stage 4) based on the measured value at this time. As the measurement unit, an encoder using a semiconductor laser can be adopted in addition to the interference measurement length device as described above.

  The supply unit 5 is installed in the vicinity of the mold holding unit 3, and supplies the imprint material R onto a shot (substrate side pattern) as a pattern formation region provided on the substrate W. The imprint material R is an ultraviolet curable resin (photo curable resin) having a property of being cured by receiving ultraviolet rays UV, and is appropriately selected according to various conditions such as a semiconductor device manufacturing process. The supply unit 5 supplies the imprint material R onto the substrate W by an inkjet method. The supply unit 5 includes a container 51 that stores an uncured imprint material R and a discharge unit 52.

  The container 51 is managed so that the imprint material R does not cause a curing reaction. The inside of the container 51 is, for example, an atmosphere containing some oxygen. It is desirable that the material of the container 51 is such that particles and chemical impurities are not mixed into the imprint material R.

  The discharge unit 52 includes, for example, a piezo-type discharge mechanism (inkjet head) including a plurality of discharge ports (supply ports). The application amount (discharge amount) of the imprint material R can be adjusted in the range of 0.1 to 10 pL / droplet, and is usually used at about 1 pL / droplet in many cases. The total application amount of the imprint material R is determined by the density of the pattern portion P and the desired remaining film thickness. Based on the operation command from the control unit 6, the supply unit 5 disperses and applies the imprint material R as droplets on the shot, and controls the application position, the application amount, and the like.

  The control unit 6 can control operation and adjustment of each component of the imprint apparatus 1. The control unit 6 is configured by, for example, a computer, is connected to each component of the imprint apparatus 1 via a line, and can control each component according to a program or the like. The control unit 6 of this embodiment controls at least the operations of the supply unit 5, the substrate stage 4, and a rotation mechanism described later. The control unit 6 may be configured integrally with other parts of the imprint apparatus 1 (in a common casing), or separate from the other parts of the imprint apparatus 1 (in another casing). To).

  Further, the imprint apparatus 1 includes an alignment measurement system 9 that measures alignment marks formed on the substrate W. The imprint apparatus 1 includes a surface plate 81 on which the substrate stage 4 is placed to form a reference plane, a bridge surface plate 82 that fixes the mold holding unit 3, and a surface plate 81 that extends from the floor surface. And a column 84 that supports the bridge surface plate 82 via a vibration isolator 83 that removes vibration. Furthermore, the imprint apparatus 1 is not shown, but a mold transport mechanism for transporting the mold M between the outside of the apparatus and the mold holding unit 3 and a substrate W between the exterior of the apparatus and the substrate stage 4. It may include a substrate transport mechanism for carrying in and out.

(Imprint method)
Next, an imprint method (imprint process) by the imprint apparatus 1 will be described. First, the control unit 6 controls the substrate transport device to place and fix the substrate W on the substrate stage 4. Next, the control unit 6 drives the stage driving unit 43 to appropriately change the position of the substrate W, and sequentially measures the alignment marks on the substrate W by the alignment measurement system 9, thereby accurately determining the position of the substrate W. To detect. The control unit 6 calculates each transfer coordinate from the detection result, and sequentially forms a pattern for each predetermined shot based on the calculation result (step-and-repeat method).

  As a flow of pattern formation for one shot, the control unit 6 first causes the stage driving unit 43 to position an application position on the substrate W (a specific position on the shot) below the discharge port of the discharge unit 52. . Thereafter, the supply unit 5 applies the imprint material R to the shot on the substrate W (application process).

  After the application, the control unit 6 causes the stage drive unit 43 to move and position the substrate W so that the shot is positioned at the pressing position directly below the pattern unit P. After positioning, the control unit 6 performs alignment of the pattern part P and the substrate side pattern on the shot, correction of the magnification of the pattern part P by the magnification correction mechanism, etc. The pattern portion P is pressed against the imprint material R (a pressing process). By this pressing, the imprint material R is filled in the uneven pattern of the pattern portion P. The control unit 6 determines whether or not the pressing is completed by a load sensor (not shown) installed in the mold holding unit 3.

  In a state where the pattern portion P is pressed against the imprint material R, the light irradiation unit 2 irradiates the UV light from the back surface (upper surface) of the mold M for a predetermined time as a curing process, and the imprint material by the UV light transmitted through the mold M. R is cured. Then, after the imprint material R is cured, the control unit 6 re-drives the mold driving unit 32 and separates the pattern unit P from the substrate W (mold release step). As a result, a three-dimensional resin pattern (layer) following the concavo-convex pattern of the pattern portion P is formed on the surface of the shot on the substrate W. By performing such a series of imprint operations a plurality of times while changing shots by driving the substrate stage 4, the imprint apparatus 1 can form a plurality of resin patterns on one substrate W. . Note that the substrate W may be moved instead of moving the mold M as described above at the time of pressing and releasing.

(Imprint material application method)
First, problems in the conventional coating method will be described. 2 and 3 show the arrangement of the imprint material R supplied to one shot area among a plurality of shot areas on the substrate W. FIG. The imprint material R is supplied to the shot area on the substrate W from the ejection unit 52 having the plurality of ejection ports 521 while moving the substrate W. Here, the moving direction of the substrate W is assumed to be the X direction. The plurality of discharge ports 521 are arranged at equal intervals in the Y direction. Therefore, the droplets of the imprint material R are also arranged at equal intervals in the Y direction in the shot region. By supplying the imprint material R while moving the substrate W in the X direction, the lines along the Y direction of the droplets of the imprint material R indicate the moving speed of the substrate W and the imprint material R of the discharge unit 52. Line up at intervals determined by the dropping period.

  In consideration of the remaining film thickness, the protrusion of the imprint material R from the end of the mold M, and the like, it is necessary to supply the imprint material R to the shot area without excess or deficiency. The distance between the droplet and the end of the shot area when the imprint material R is arranged in the shot area without excess or deficiency in the Y direction is defined as a. FIG. 2 shows that the imprint material R is supplied more than expected, that is, the imprint material R protrudes from the end of the mold M. If the distance that the imprint material R does not protrude from the end of the mold M and does not become unfilled is a, the distance b is smaller than the distance a.

  FIG. 3 shows a case where the ejection of the imprint material R through the ejection port 521 that supplies the imprint material R at the distance b is stopped. In this case, the distance c between the lower end of the line along the Y direction of the imprint material R and the end of the shot region is a distance c that is larger than the distance a. That is, the imprint material R supplied to the shot area is insufficient and unfilled.

  The arrangement of the droplets of the imprint material R in the Y direction is determined by the interval between the ejection ports 521. Therefore, unlike the arrangement in the X direction, there is no degree of freedom in the arrangement of the droplets of the imprint material R in the Y direction. That is, in the conventional coating method, for example, it may be difficult to satisfy both the protrusion of the imprint material R from the end of the mold M and the unfilled problem.

  In the present embodiment, the ejection unit 52 ejects the first ejection unit 52x that ejects the droplet line of the imprint material R aligned in the X direction and the second droplet that ejects the droplet line of the imprint material R aligned in the Y direction. It has a discharge part 52y. The 1st discharge part 52x has the discharge outlet 53 arrange | positioned at equal intervals in the X direction. The second discharge part 52y has discharge ports 54 arranged at equal intervals in the Y direction. The number and interval of the discharge ports in each discharge unit may be the same or different.

  FIG. 4 shows a state in which the imprint material R is supplied to the shot region using only the second ejection unit 52y. The distance between the droplet and the end of the shot area when the imprint material R is disposed in the shot area without excess or deficiency in the X direction is defined as a distance d. As shown in FIG. 4, by controlling the moving speed of the substrate W in the X direction and the like, the imprint material R is supplied without excess or deficiency in the X direction using only the second ejection part 52y. The supply of the imprint material R by the second discharge unit 52y is referred to as a first step.

  FIG. 5 shows a state in which the imprint material R is supplied to the shot region using only the first ejection unit 52x (second step). A distance a between the droplet and the end of the shot area when the imprint material R is arranged in the shot area without excess or deficiency in the Y direction is defined as a distance a. The droplets of the imprint material R arranged by the first ejection unit 52x (second process) are black circles, and the droplets of the imprint material R arranged by the second ejection unit 52y (first process) are white. It is a round circle. As shown in FIG. 5, by controlling the moving speed of the substrate W in the Y direction and the like, droplets of the imprint material R are placed at positions where the second discharge unit 52y alone cannot be disposed using the first discharge unit 52x. It has been arranged.

  The first step and the second step may be alternately repeated. Further, the moving speed of the substrate W and the supply cycle of the imprint material R by the supply unit 5 may be changed between the first process and the second process (third process). The change may be performed during the first step or the second step. In the above embodiment, it is necessary to change the discharge port between the first step and the second step (fourth step). However, according to the discharge unit of the following modification, this step is not necessary. According to the above supply method, the supply position of the imprint material is not limited to the above-described embodiment in which the supply position is vertically and horizontally symmetrical, and it is possible to deal with an asymmetric supply position.

According to the imprint material supply method of the present embodiment, the degree of freedom of the imprint material supply position to the shot area can be improved, and the imprint material can be supplied to the shot area without excess or deficiency.
(Modification of discharge part)

  6 to 8 show modified examples of the arrangement of the discharge ports of the discharge unit. FIG. 6 shows a discharge unit 62 having a group of discharge ports 621 arranged at predetermined intervals in the X direction and the Y direction. FIG. 7 shows a discharge section 72 having discharge ports 721 arranged in an L shape. FIG. 8 shows the discharge part 82 in which the discharge ports 821 are arranged obliquely so as to intersect the X direction and the Y direction. The same effects as those of the above embodiment can be obtained by any of the ejection units. For example, according to the discharge unit 62, the discharge port 621 arranged in the Y direction among the discharge ports 621 is used to move the substrate W in the X direction and supply the imprint material R in the X direction without excess or deficiency. Can do. And about the Y direction, the imprint material R can be supplied without excess and deficiency by moving the board | substrate W to a Y direction using the discharge outlet 621 located in a line with the X direction. Further, according to the discharge unit 82, when the substrate W is moved in the X direction and the imprint material R is supplied in the X direction, the substrate W is moved in the Y direction and the imprint material R is supplied in the Y direction. The inclination angle of the discharge port 821 at the time can be changed. By tilting the discharge port 821, the imprint material R can be freely arranged.

(Embodiment related to article manufacturing method)
A method for manufacturing a device (semiconductor integrated circuit element, liquid crystal display element, etc.) as an article includes a step of forming a pattern on a substrate (wafer, glass plate, film-like substrate) by an imprint apparatus using the method described above. . Furthermore, the manufacturing method may include a step of etching the substrate on which the pattern is formed. When manufacturing other articles such as patterned media (recording media) and optical elements, the manufacturing method may include other processes for processing a substrate on which a pattern is formed instead of etching. The method for manufacturing an article according to 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.

(Other embodiments)
As mentioned above, although embodiment of this invention has been described, this invention is not limited to these embodiment, A various change is possible within the range of the summary.

DESCRIPTION OF SYMBOLS 1 Imprint apparatus 5 Supply part 52x 1st discharge part 52y 2nd discharge part R Imprint material W board | substrate

Claims (10)

An imprint method in which an uncured imprint material on a substrate is molded by a mold and cured, and a pattern of the cured imprint material is formed in a plurality of shot regions provided on the substrate,
A first step of supplying the uncured imprint material to one shot region among a plurality of shot regions on the substrate while moving the substrate in a first direction along the surface of the substrate;
A second step of supplying the uncured imprint material to the one shot region while moving the substrate along a surface of the substrate and in a second direction orthogonal to the first direction;
The imprint method characterized by having.   The imprint method according to claim 1, wherein the first step and the second step are alternately repeated.   The imprint method according to claim 1, further comprising a third step of changing a moving speed of the substrate or a supply cycle of the uncured imprint material.   The imprint method according to claim 3, wherein the third step is provided between the first step and the second step.   The imprint method according to claim 3, further comprising the third step between the first step and the second step.   6. The method according to claim 1, further comprising a fourth step of changing a dispenser that supplies the uncured imprint material between the first step and the second step. Imprint method An imprint apparatus that forms an uncured imprint material on a substrate with a mold and cures, and forms a pattern of the cured imprint material on a plurality of shot regions provided on the substrate,
A substrate holding unit that holds and moves the substrate;
A dispenser for supplying the uncured imprint material on the substrate,
The substrate holding unit moves the substrate in a first direction along the surface of the substrate, or in a second direction orthogonal to the first direction,
The dispenser supplies the uncured imprint material to one shot area among a plurality of shot areas on the moving substrate.
An imprint apparatus characterized by that. The dispenser has a plurality of supply ports for supplying the uncured imprint material,
The plurality of supply ports include a group arranged in a direction along the first direction and a group arranged in a direction along the second direction.
The imprint apparatus according to claim 7. The dispenser has a plurality of supply ports for supplying the uncured imprint material,
The plurality of supply ports are arranged in a direction intersecting the first direction and the second direction.
The imprint apparatus according to claim 7. A step of performing pattern formation on the substrate using the imprint apparatus according to claim 7;
Processing the substrate on which the pattern has been formed in the step;
A method for producing an article comprising:

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