JP6938247B2 - Imprint method, imprint device, and article manufacturing method - Google Patents

Description

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

There is an imprint method as one of the lithography methods for manufacturing articles such as semiconductor devices and liquid crystal displays. 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 the uncured imprint material on the substrate, a method of supplying the uncured imprint material of uniform thickness to a plurality of target areas (shot regions) of the substrate by using a plurality of nozzles arranged in parallel. (Patent Document 1).

Japanese Unexamined Patent Publication No. 2007-273979

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

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

In order to solve the above problems, the present invention forms an uncured imprint material on a substrate with a mold and cures the imprint material, and forms a pattern of the cured imprint material in a plurality of shot regions provided on the substrate. This is an imprinting method in which an uncured imprint material is applied to one shot region from a plurality of discharge ports while moving the substrate in the first direction along the surface of the substrate. The droplets imparted in the first step of one shot region while moving the substrate along the surface of the substrate and in the second direction orthogonal to the first direction in the first step of supplying as a plurality of droplets. characterized in different positions, and a second step of supplying an imprint material uncured as a plurality of droplets from a plurality of discharge ports, to have a the.

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

It is the schematic which shows the structure of the imprint apparatus which uses the imprint method which concerns on embodiment. The state when the imprint material protrudes from the end of the mold is shown. The case where the discharge of the imprint material by a part of the plurality of discharge ports is stopped is shown. It shows how the imprint material is supplied to the shot area using only one discharge part. It shows how the imprint material is supplied to the shot area using only the other discharge part. A discharge unit having discharge ports arranged at predetermined intervals in the X direction and the Y direction is shown. Indicates a discharge unit having discharge ports arranged in an L shape. The discharge portion where the discharge port is diagonally arranged so as to intersect the X direction and the Y direction is shown.

Hereinafter, embodiments for carrying out the present invention will be described with reference to drawings and the like. In each drawing, the same members or elements are given the same reference numbers, and duplicate description will be omitted.
[Embodiment]

(Imprint device)
FIG. 1 is a schematic view showing a configuration of an imprinting apparatus using the imprinting method according to the embodiment of the present invention. Here, as an imprinting apparatus using the photocuring method, an ultraviolet curable imprinting 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 by irradiating light in another wavelength range or a method using other energy (for example, heat) may be used. Further, in the following figure, the Z-axis is taken parallel to the optical axis of the ultraviolet rays radiated to the imprint material on the substrate, and the X-axis and the Y-axis that are orthogonal to each other are taken in a plane perpendicular to the Z-axis. ing.

The imprint device 1 includes a light irradiation unit 2, a mold holding unit 3, a substrate stage (board 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 and UV rays during the imprint processing. Although not shown, the light irradiation unit 2 includes a light source and an illumination optical system that adjusts ultraviolet UV emitted from the light source to light suitable for imprinting and irradiates the mold M with light. As the light source, lamps such as a mercury lamp can be adopted, but the light source is not particularly limited as long as it is a light source that transmits light through the mold M and emits light having a wavelength at which the imprint material R described later is cured. Illumination optics may include lenses, mirrors, apertures, or shutters for switching between irradiation and shading. In the present embodiment, the light irradiation unit 2 is installed in order to adopt the photocuring method. For example, when the heat curing method is adopted, the thermosetting unit 2 is replaced with the thermosetting unit 2. A heat source unit for curing the resin will be installed.

The outer peripheral shape of the mold M is polygonal (preferably rectangular or square), and a pattern in which a concavo-convex pattern to be transferred such as a circuit pattern is formed three-dimensionally on the surface with respect to the substrate W. Includes part P. The pattern size varies depending on the article to be manufactured, but a fine pattern of a dozen nanometers is also included. Further, it is desirable that the material of the mold M is capable of transmitting ultraviolet rays and UV rays 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 planar shape and a certain depth on the surface irradiated with ultraviolet rays and UV rays.

The mold holding portion 3 corrects the shape of the mold M (pattern portion P), although not shown, the mold chuck 31 for holding the mold M and the mold driving portion 32 for movably holding the mold chuck 31. It has a magnification correction mechanism. The mold chuck 31 can hold the mold M by attracting the outer peripheral region of the ultraviolet UV irradiation surface of the mold M by a vacuum suction force or an electrostatic force. For example, when the mold M is held by a vacuum suction force, the mold chuck 31 is connected to a vacuum pump (not shown) installed outside, and the suction pressure is appropriately adjusted by the exhaust of the vacuum pump to obtain the mold M with respect to the mold M. The suction force (holding force) 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 adopted in the mold drive unit 32 include a linear motor and an air cylinder. Further, the mold drive unit 32 may be composed of a plurality of drive systems such as a coarse movement drive system and a fine movement drive system in order to support highly accurate positioning of the mold M. Further, the mold drive unit 32 has a position adjusting function 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, and a tilt function for correcting the inclination of the mold M. There may be a configuration having.

The pressing and pulling operations of the imprint device 1 may be realized by moving the mold M in the Z-axis direction, but may also be realized by moving the substrate stage 4 in the Z-axis direction. , Or both may be moved relative to each other. Further, although the position of the mold M when the mold driving unit 32 is driven is not shown, it can be measured by a position measuring unit 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 holding side of the mold M in the mold chuck 31 and corrects the shape of the mold M (pattern portion P) by mechanically applying an external force or a displacement to the side surface of the mold M.

Further, the mold chuck 31 and the mold drive unit 32 have an opening region 33 in the central portion (inside) in the plane direction so that the ultraviolet UV emitted from the light irradiation unit 2 can pass toward the substrate W.

The substrate (wafer) W is, for example, a single crystal silicon substrate, an SOI (Silicon on Insulator) substrate, or a glass substrate. A pattern portion P is used to cover a plurality of pattern forming regions on the substrate W (a pattern (hereinafter referred to as "board side pattern") is already formed in a previous step before being carried into the imprinting apparatus 1). A pattern (layer containing the pattern) of the imprint material R is formed.

The substrate stage 4 holds the substrate W movably, and for example, aligns the pattern portion P with the substrate side pattern when the mold M and the imprint material R on the substrate W are pressed against each other. The substrate stage 4 mechanically holds the wafer chuck 41 that holds the substrate W by an attractive force, the auxiliary member 42 that is installed so as to surround the outer periphery of the substrate W, and the wafer chuck 41, and moves in each axial direction. It has a stage drive unit 43 that enables it.

The wafer chuck 41 supports the substrate W by, for example, a plurality of pins having the same height, and holds the substrate W by decompressing a portion other than the pins by vacuum exhaust. The auxiliary member 42 has a surface height equivalent to that of the substrate W mounted on the wafer chuck 41, and is used for uniforming the thickness of the resin pattern at the outer peripheral end of the substrate W.

The stage drive unit 43 is a power source with less vibration during driving and stationary, and examples of the power source that can be adopted include a linear motor and a flat motor. The stage drive unit 43 may also be composed of a plurality of drive systems such as a coarse movement drive system and a fine movement drive system in each of the X-axis and Y-axis directions. Further, there may be a configuration having a drive system for adjusting the position in the Z-axis direction, a position adjusting function in the θ direction of the substrate W, a tilt function for correcting the inclination of the substrate W, and the like.

Further, the substrate stage 4 is provided with a plurality of reference mirrors 44 corresponding to each direction of X, Y, Z, ωx, ωy, and ωz on its side surface. On the other hand, the imprint device 1 includes a plurality of laser interferometers (measurement units) 7 for measuring the position of the substrate stage 4 by irradiating each of these reference mirrors 44 with a beam such as helium neon. Note that FIG. 1 illustrates only one set of the reference mirror 44 and the laser interferometer 7. 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 (board stage 4) based on the measured values at this time. As the measuring unit, an encoder using a semiconductor laser or the like can be adopted in addition to the above-mentioned interference measuring length device.

The supply unit 5 is installed in the vicinity of the mold holding unit 3 and supplies the imprint material R on a shot (a pattern on the substrate side) as a pattern forming region provided on the substrate W. The imprint material R is an ultraviolet curable resin (photocurable resin) having a property of being cured by receiving ultraviolet UV rays, and is appropriately selected depending on 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 for accommodating the 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 has, for example, an atmosphere containing a small amount of oxygen. It is desirable that the material of the container 51 is such that particles and chemical impurities are not mixed in the imprint material R.

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

The control unit 6 can control the operation and adjustment of each component of the imprint device 1. The control unit 6 is composed of, for example, a computer or the like, is connected to each component of the imprint device 1 via a line, and can execute control of each component according to a program or the like. The control unit 6 of the present embodiment controls at least the operations of the supply unit 5, the substrate stage 4, and the rotation mechanism described later. The control unit 6 may be integrally configured with other parts of the imprint device 1 (in a common housing), or may be separated from the other parts of the imprint device 1 (in a different housing). It may be configured.

Further, the imprint device 1 includes an alignment measurement system 9 for measuring an alignment mark formed on the substrate W. Further, the imprint device 1 extends from a surface plate 81 on which the substrate stage 4 is placed to form a reference plane, a bridge surface plate 82 for fixing the mold holding portion 3, and the surface plate 81, and is provided from the floor surface. A support column 84 that supports the bridge surface plate 82 via a vibration isolator 83 that removes vibration is provided. Further, although both of the imprint devices 1 are not shown, a mold transfer mechanism for loading and unloading the mold M between the outside of the device and the mold holding unit 3 and a substrate W between the outside of the device and the substrate stage 4 are provided. It may include a substrate transport mechanism for loading and unloading.

(Imprint method)
Next, the imprint method (imprint process) by the imprint device 1 will be described. First, the control unit 6 controls the substrate transfer device to mount and fix the substrate W on the substrate stage 4. Next, the control unit 6 drives the stage drive 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, so that the position of the substrate W is highly accurate. To detect. Then, the control unit 6 calculates each transfer coordinate from the detection result, and forms a sequential pattern for each predetermined shot based on the calculation result (step and repeat method).

As a flow of pattern formation for a certain shot, the control unit 6 first positions the coating position (a specific position on the shot) on the substrate W under the discharge port of the discharge unit 52 by the stage drive unit 43. .. After that, the supply unit 5 applies the imprint material R to the shot on the substrate W (coating step).

After coating, the control unit 6 moves and positions the substrate W by the stage drive unit 43 so that the shot is positioned at the pressing position directly below the pattern unit P. After positioning, the control unit 6 aligns the pattern unit P with the substrate-side pattern on the shot, corrects the magnification of the pattern unit P by the magnification correction mechanism, and then drives the mold drive unit 32 to drive the mold drive unit 32 on the shot. The pattern portion P is pressed against the imprint material R (molding process). By this pressing, the imprint material R is filled in the uneven pattern of the pattern portion P. The control unit 6 determines the completion of pressing by a load sensor (not shown) installed inside the mold holding unit 3.

With the pattern portion P pressed against the imprint material R, the light irradiation unit 2 irradiates ultraviolet UV from the back surface (upper surface) of the mold M for a predetermined time as a curing step, and the imprint material is irradiated with ultraviolet UV transmitted through the mold M. Cure R. Then, after the imprint material R is cured, the control unit 6 redrives the mold drive unit 32 and separates the pattern unit P from the substrate W (molding step). As a result, a three-dimensional resin pattern (layer) that follows the uneven pattern of the pattern portion P is formed on the surface of the shot on the substrate W. By performing such a series of imprinting operations a plurality of times while changing shots by driving the substrate stage 4, the imprinting apparatus 1 can form a plurality of resin patterns on one substrate W. .. At the time of pressing and releasing, the substrate W may be moved instead of moving the mold M as described above.

(How to apply imprint material)
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 region among the plurality of shot regions on the substrate W. The imprint material R is supplied to the shot region on the substrate W from the ejection portion 52 having a plurality of ejection ports 521 while moving the substrate W. Here, the moving direction of the substrate W is 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 of the droplets of the imprint material R along the Y direction are the moving speed of the substrate W and the imprint material R of the ejection portion 52. Line up at intervals determined by the dropping cycle.

It is necessary to supply the imprint material R to the shot region in just proportion in consideration of the residual film thickness, the protrusion of the imprint material R from the end of the mold M, and the like. Let a be the distance between the droplet and the edge of the shot region when the imprint material R is arranged in the shot region in the Y direction without excess or deficiency. FIG. 2 shows that the imprint material R is supplied in a larger amount than expected, that is, the imprint material R protrudes from the end portion of the mold M. Assuming that the distance a is such that the imprint material R does not protrude from the end of the mold M and is not unfilled, the distance b is smaller than the distance a.

FIG. 3 shows a case where the discharge of the imprint material R is stopped by the discharge port 521 that supplies the imprint material R to the distance b. In this case, the distance 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 larger than the distance a. That is, the imprint material R supplied to the shot region is insufficient and unfilled.

The arrangement of the droplets of the imprint material R in the Y direction is determined by the distance between the discharge 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 achieve both the problem of the imprint material R protruding from the end portion of the mold M and the problem of not filling.

In the present embodiment, the discharge unit 52 discharges the first discharge unit 52x for discharging the droplet line of the imprint material R arranged in the X direction and the second discharge unit 52 for discharging the droplet line of the imprint material R arranged in the Y direction. It has a discharge unit 52y. The first discharge unit 52x has discharge ports 53 arranged at equal intervals in the X direction. The second discharge unit 52y has discharge ports 54 arranged at equal intervals in the Y direction. The number and intervals of discharge ports may be the same or different in each discharge portion.

FIG. 4 shows a state in which the imprint material R is supplied to the shot region using only the second discharge unit 52y. Let the distance d be the distance between the droplet and the end of the shot region when the imprint material R is arranged in the shot region in the X direction without excess or deficiency. 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 in the X direction without excess or deficiency using only the second discharge unit 52y. The supply of the imprint material R by the second discharge unit 52y is referred to as the first step.

FIG. 5 shows a state in which the imprint material R is supplied to the shot region using only the first discharge portion 52x (second step). Let the distance a be the distance between the droplet and the end of the shot region when the imprint material R is arranged in the shot region in the Y direction without excess or deficiency. The droplets of the imprint material R arranged by the first discharge portion 52x (second step) are black-painted circles, and the droplets of the imprint material R arranged by the second discharge portion 52y (first step) 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, the droplet of the imprint material R is generated at a position where the first ejection portion 52x cannot be arranged only by the second ejection portion 52y. It can be placed.

The first step and the second step may be repeated alternately. 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 step and the second step (third step). The change may be made during the first step or the second step. Further, in the above embodiment, it is necessary to change the discharge port between the first step and the second step (fourth step), but according to the discharge portion of the following modified example, this step is unnecessary. According to the above supply method, not only the above-described embodiment in which the supply position of the imprint material is symmetrical in the vertical and horizontal directions, but also an asymmetrical supply position can be supported.

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

6 to 8 show a modified example of the arrangement of the discharge port included in the discharge portion. 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 unit 72 having discharge ports 721 arranged in an L shape. FIG. 8 shows a discharge portion 82 in which the discharge port 821 is diagonally arranged so as to intersect the X direction and the Y direction. The same effect as that of the above-described embodiment can be obtained by any of the discharge portions. For example, according to the discharge unit 62, among the discharge ports 621, the discharge ports 621 arranged in the Y direction are 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 be done. Then, in the Y direction, the imprint material R can be supplied without excess or deficiency by moving the substrate W in the Y direction by using the discharge ports 621 arranged in the X direction. Further, according to the discharge unit 82, when the substrate W is moved in the X direction to supply the imprint material R in the X direction, and when the substrate W is moved in the Y direction to supply the imprint material R 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 relating to article manufacturing method)
A method for manufacturing a device as an article (semiconductor integrated circuit element, liquid crystal display element, etc.) includes a step of forming a pattern on a substrate (wafer, glass plate, film-like substrate) by an imprinting apparatus using the above-mentioned method. .. Further, the manufacturing method may include a step of etching the patterned substrate. When manufacturing other articles such as patterned media (recording media) and optical elements, the manufacturing method may include other processing of processing a patterned substrate instead of etching. 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.

(Other embodiments)
Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications can be made within the scope of the gist thereof.

1 Imprint device 5 Supply unit 52x 1st discharge unit 52y 2nd discharge unit R Imprint material W substrate

Claims (11)

An imprint method in which an uncured imprint material on a substrate is molded with a mold and cured to form a pattern of the cured imprint material in a plurality of shot regions provided on the substrate.
While moving the substrate in the first direction along the surface of the substrate, a plurality of droplets of the uncured imprint material from a plurality of ejection ports in one shot region among the plurality of shot regions on the substrate. The first step to supply as
While moving the substrate along the surface of the substrate and in the second direction orthogonal to the first direction, the substrate is placed at a position different from the droplets applied in the first step in the one shot region. The second step of supplying the uncured imprint material as multiple droplets from multiple ejection ports, and
An imprinting method characterized by having. The imprint method according to claim 1, wherein the second step is supplied to the outer peripheral end of the one shot region. The imprint method according to claim 1, wherein the first step and the second step are alternately repeated. The imprint method according to any one of claims 1 to 3, further comprising a third step of changing the moving speed of the substrate or the supply cycle of the uncured imprint material. The imprint method according to claim 4 , wherein the third step is provided between the first step and the second step. The imprint method according to claim 4 , wherein the third step is provided during the first step or between the second steps. The invention according to any one of claims 1 to 6 , further comprising a fourth step of changing the dispenser for supplying the uncured imprint material between the first step and the second step. Imprint method An imprinting apparatus in which an uncured imprint material on a substrate is molded by a mold and cured to form a pattern of the cured imprint material in a plurality of shot regions provided on the substrate.
A substrate holding portion that holds and moves the substrate,
A dispenser having a plurality of supply ports for supplying droplets of the uncured imprint material on the substrate.
The substrate holding portion 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 of the plurality of shot areas on the substrate that the mobile is intended for supplying the uncured imprint material to one shot area,
While moving the substrate in the first direction, the uncured imprint material is supplied to the one shot region as a plurality of droplets from the plurality of supply ports.
The plurality of uncured imprint materials are placed at positions different from the droplets supplied while moving the substrate in the second direction and moving the substrate in the first direction in the one shot region. Supply as multiple droplets from the supply port,
An imprinting device characterized by this. Before SL plurality of supply ports includes a group which is arranged in a direction along the first direction, and groups that are arranged in a direction along the second direction, and
The imprinting apparatus according to claim 8. Before SL plurality of supply ports are arranged in a direction intersecting the first direction and the second direction,
The imprinting apparatus according to claim 8. A step of forming a pattern on a substrate using the imprinting apparatus according to any one of claims 8 to 10.
A step of processing the substrate on which the pattern was formed in the step and a step of processing the substrate.
A method of manufacturing an article, which comprises.

Images