WO2017104382A1

WO2017104382A1 - Imprint apparatus, and method of manufacturing article

Info

Publication number: WO2017104382A1
Application number: PCT/JP2016/084972
Authority: WO
Inventors: Kazuki Nakagawa
Original assignee: Canon Kabushiki Kaisha
Priority date: 2015-12-16
Filing date: 2016-11-25
Publication date: 2017-06-22
Also published as: JP2017112231A; KR20180090357A; KR102081527B1; JP6700771B2

Abstract

An imprint apparatus includes a facing member that is arranged around a mold and faces a substrate, a first supply unit configured to supply a first gas between the mold and the substrate from a first supply port arranged between the mold and the facing member, and a second supply unit configured to supply a second gas between the facing member and the substrate from a second supply port arranged in the facing member. The facing member includes, between the first supply port and the second supply port, a flow path configured to guide the second gas which flows from the second supply port toward the mold to bypass the space between the mold and the substrate.

Description

IMPRINT APPARATUS, AND METHOD OF MANUFACTURING ARTICLE

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

An imprint technique is coming into practical use as one lithography technique for manufacturing an article such as a magnetic storage medium and a semiconductor device. Since an imprint apparatus forms a pattern by bringing a mold into contact with an imprint material on a substrate, a pattern defect is generated more easily in principle when compared to a conventional exposure apparatus.

One cause of pattern defect generation is that bubbles are easily trapped between the mold and the imprint material when the pattern portion of the mold is brought into contact with the imprint material. If the imprint material is cured while the bubbles remain, a defect due to unfilling is undesirably generated in a formed pattern.

Another cause of pattern defect generation is the adherence of a foreign substance (particle) on the pattern surface of the mold. If a particle adheres to the pattern surface, the pattern to be formed on the substrate is distorted and a transfer defect is generated. As a result, depending on the degree of the defect, the mold may be broken.

In regard to these problems, Japanese Patent Laid-Open No. 2014-056854 discloses a technique in which a functional gas is supplied between a mold and an imprint material to promote the elimination of bubbles and an air curtain is formed from the peripheral portion of the mold toward a substrate to prevent a foreign substance from entering between the mold and the substrate from outside.

Here, in an arrangement in which a functional gas is supplied in the gap between the mold and the substrate while an air curtain air flow is formed on the substrate, the functional gas and the air curtain air flow may become mixed. If the functional gas and the air curtain air flow become mixed, the density of the functional gas in the gap between the mold and the substrate cannot be sufficiently increased, and a portion unfilled by the imprint material will be generated in the pattern portion of the mold, thereby increasing the possibility of defect generation. Hence, a gas curtain structure that can suppress the adherence of a foreign substance on the substrate without impeding the filling of an imprint space by the functional gas is necessary.

The present invention provides, for example, an imprint apparatus advantageous in accurate pattern formation.

According to one aspect of the present invention, an imprint apparatus that forms a pattern of an imprint material on a substrate by using a mold is provided. The apparatus comprises a facing member that is arranged around the mold and faces the substrate, a first supply unit configured to supply a first gas between the mold and the substrate from a first supply port arranged between the mold and the facing member, and a second supply unit configured to supply a second gas between the facing member and the substrate from a second supply port arranged in the facing member. The facing member includes, between the first supply port and the second supply port, a flow path configured to guide the second gas which flows from the second supply port toward the mold to bypass the space between the mold and the substrate.

Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

Fig. 1 is a view of the arrangement of an imprint apparatus according to an embodiment. Fig. 2 is a view for explaining an air flow caused by a groove portion according to the embodiment. Fig. 3 is a view showing an example of the shape of the outer edge of the groove portion according to the embodiment. Fig. 4 is a view of the arrangement of the imprint apparatus according to a modification.

Various exemplary embodiments, features, and aspects of the invention will be described in detail below with reference to the drawings. Note that the following embodiments are not intended to limit the present invention and are merely concrete examples in practicing the invention. Furthermore, not all combinations of features explained in the following embodiments are essential for the present invention to solve the problem.

Fig. 1 is a view showing the arrangement of an imprint apparatus 1 according to this embodiment. The imprint apparatus 1 is used for manufacturing an article such as a semiconductor device and is an apparatus that forms a pattern on a substrate by bringing an imprint material and a mold into contact on the substrate to be processed and curing the imprint material. In this embodiment, the imprint apparatus adopts a photo-curing method of curing an imprint material by ultraviolet-light irradiation. The present invention, however, is not limited to this. For example, a heat-curing method of curing an imprint material by application of heat can be adopted. Additionally, in the drawings, the Z-axis is set parallel to the optical axis of an illumination system which irradiates the imprint material on the substrate with ultraviolet light, and the X-axis and the Y-axis are set orthogonal to each other within a plane perpendicular to the Z-axis.

At the time of an imprint process, a light irradiation unit 20 irradiates an imprint material 8 (for example, a photo-curing resin) with ultraviolet light 21. Although not shown, the light irradiation unit 20 can include an exposure light source and an optical element which adjusts the ultraviolet light 21 emitted from this exposure light source into a light appropriate for imprinting. A mold 4 is formed from a material such as silica glass or the like that has a rectangular peripheral shape and can pass the ultraviolet light 21. The mold 4 includes a pattern portion 5 on which a predetermined pattern such as a circuit pattern has been formed on the surface that faces the substrate 2.

A mold holder 6 includes a driving mechanism that moves the mold 4 while holding the mold 4. The mold holder 6 can hold the mold 4 by drawing the peripheral region of the surface irradiated with the ultraviolet light 21 of the mold 4 by vacuum suction force or electrostatic force. The mold holder 6 moves the mold 4 in the direction of each axis so as to selectively bring the mold 4 into contact with the imprint material 8 on the substrate 2 (mold contact) and separate them (mold separation). Additionally, in order to cope with the highly precise positioning of the mold 4, the mold holder 6 may be formed from a plurality of driving systems such as a coarse driving system and a fine driving system. Furthermore, an arrangement including a positioning function not only in the Z-axis direction but also in the X-axis direction and the Y-axis direction or the θ direction of each axis and a tilt function for correcting the tilt of the mold 4 may be provided. Note that the mold contact and mold separation operations of the imprint apparatus 1 may be implemented by moving the mold 4 in the Z-axis direction. However, it may also be implemented by moving the substrate stage 3 in the Z-axis direction or by moving both the mold 4 and the substrate stage 3 relative to each other.

The substrate 2 is, for example, a single crystal silicon substrate or a SOC (Silicon on Insulator) substrate, and its surface to be processed is coated with an ultraviolet-light curing imprint material 8 which is formed into a pattern by the pattern portion 5 formed on the mold 4. The substrate stage 3 holds the substrate 2 and implements the positioning of the mold 4 and the imprint material 8 when the mold 4 and the imprint material 8 on the substrate 2 are brought into contact. In addition, the substrate stage 3 includes a stage driving mechanism (not shown) that can move the stage in the direction of each axis. The stage driving mechanism may be formed from a plurality of driving systems such as a coarse driving system and a fine driving system with respect to the X-axis and Y-axis directions. Furthermore, an arrangement which includes a driving system for positioning in the Z-axis direction, a positioning function in the θ direction of the substrate 2, or a tilt function for correcting the tilt of the substrate 2 may be provided.

In this embodiment, a facing member 15 that faces the substrate 2 is arranged around the mold 4. The facing member 15 is arranged so as to always face the substrate 2 within the moving range of a substrate stage 3. A dispenser 7 is provided near the mold holder 6, for example, inside the facing member 15 and dispenses (supplies) the imprint material 8 onto the substrate 2. The imprint material 8 is, for example, a photo-curing composition having a property in which it is cured by receiving the ultraviolet light 21, and can be selected, as needed, in a semiconductor device manufacturing step or the like. In addition, the amount of the imprint material 8 dispensed from the dispenser 7 and its distribution on the substrate are determined appropriately by the desired thickness of the imprint material 8 to be formed on the substrate 2, the density of the pattern to be formed, or the like.

The imprint apparatus 1 includes a first supply unit that supplies a first gas 13 in the gap between the mold 4 and the imprint material 8 on the substrate 2 upon mold contact. This is provided to shorten the time taken for the imprint material 8 to fill the three-dimensional pattern of the pattern portion 5 and to improve the filling property to prevent bubbles from remaining in the filled portion. The first supply unit includes a first gas supply source 14 and first gas nozzles 12 (first supply ports) which are connected to the first gas supply source. The first gas nozzles 12 are arranged between the mold 4 and the facing member 15. For example, the first gas nozzles 12 may be arranged inside the mold holder 6. The first gas nozzles 12 may be provided so as to be adjacent to only one side of the mold 4 or to surround the mold 4. Here, as the first gas 13, a condensable gas which is liquefied when the pressure rises in the space between the mold and the substrate at the time of mold contact or a highly diffusible gas from the point of view of filling property or a gas having excellent solubility toward the imprint material can be adopted. Particularly, for example, nitrogen, helium, carbon dioxide, hydrogen, xenon, or pentafluoropropane can be adopted.

After the imprint material 8 is supplied to the substrate 2 in a state 1a in which the substrate 2 faces the dispenser 7, the mold 4 and the substrate 2 are positioned in a predetermined positional relationship in a state 1b in which the substrate 2 faces the mold 4. Subsequently, the mold holder 6 moves in the -Z direction so that the pattern portion 5 is brought into contact with the imprint material 8 and the imprint material 8 on the substrate 2 is formed.

Here, the pattern portion 5 may become damaged if the pattern portion 5 is brought into contact with the imprint material 8 in a state in which a foreign substance, such as a particle, has adhered to the shot region on the substrate 2 or the pattern portion 5. The imprint apparatus is placed in a clean environment for manufacturing semiconductor devices, but it is difficult to completely eliminate the generation of a foreign substance. A foreign substance can be generated due to the material itself forming the imprint apparatus, the sliding of the materials, or when the imprint apparatus is brought in from outside. Although it varies depending on the pattern dimension and the pattern depth of the pattern portion 5, the possibility of pattern defect generation increases when a foreign substance of a size equal to or larger than a half pitch dimension is present.

Hence, the imprint apparatus 1 further includes a second supply unit that supplies a second gas 10 in the gap between the facing member 15 and the substrate 2. The second supply unit includes a second gas supply source 11 and second gas nozzles 9 (second supply ports) which are connected to the second gas supply source. The second gas nozzles 9 are arranged in the facing member 15. The second gas nozzles 9 can be provided so as to surround the mold 4. A foreign substance can be prevented from entering the imprint space by blowing the second gas 10 such as air to the substrate 2. The second gas 10 that is blown from the second gas nozzles 9 onto the substrate 2 forms a gas curtain such as an air curtain by an air flow which is shown by arrows heading from the gap space formed between the substrate 2, the mold 4, and the facing member 15 to the peripheral side of the substrate stage 3.

Here, as shown in the state 1a of Fig. 1, since the gap between the mold 4 and the imprint material 8 is filled with the first gas 13 after the imprint material 8 is supplied to the substrate 2, the first gas 13 is drawn in below the mold 4 due to the Couette flow caused by the movement of the substrate stage 3. In this case, the second gas 10 blown out from the second gas nozzles 9 forms an air flow from the space between the substrate 2 and the facing member 15 toward the peripheral side of the substrate stage 3. Since the facing member 15 is arranged so as to always face the substrate 2 within the moving range of the substrate stage 3, an air flow to the peripheral side of the substrate stage 3 is formed by the second gas 10. However, if an air flow has occurred in the region where the first gas 13 is supplied, the first gas 13 and the second gas 10 may become mixed and the density of the first gas 13 may decrease. This may impair the filling property of the imprint material 8.

Therefore, as shown in Figs. 1, 2, and 3, in the imprint apparatus 1 according to this embodiment, a flow path is provided between the first gas nozzles 12 and the second gas nozzles 9 in the facing member 15. This flow path is formed so as to guide the second gas 10, which is flowing from the second gas nozzles 9 to the mold 4, to bypass the space (imprint space) between the mold 4 and the substrate 2 (imprint material 8). Here, the first gas bypasses at least the space between the pattern portion 5 of the mold 4 and the substrate 2. This kind of a flow path can be formed by, for example, a groove portion 16 formed in the surface of the facing member 15 which faces the substrate 2.

An opening width w1 of each groove portion 16 is larger than a distance (Z-axis direction distance) h1 between the substrate 2 and the facing member 15. Hence, the second gas 10 flowing between the substrate 2 and the facing member 15 in the direction where the first nozzles 12 (the mold 4) are present flows preferentially into the groove portion 16 which is easier to flow and the flow below the first gas nozzles 12 is suppressed. Here, particularly, the distance between the substrate 2 and the facing member 15 is the distance when the substrate stage 3 moves, after the imprint material has been applied on the substrate 2, to move the region supplied with the imprint material below the pattern portion 5 of the mold 4. In addition, as shown in Fig. 2, the groove portion 16 is formed so as to surround the mold 4 and the first gas nozzles 12. For example, a space 16b larger than an opening portion 16a is formed inside the groove portion 16. That is, the section of the groove portion 16 is formed to have a larger width than the opening width w1. As a result, the second gas 10 that has flowed into the groove portion 16 flows out from the opening portion 16a on the opposite side by using the space 16b as a bypass in the manner shown by a dotted line arrow 16c in Figs. 1 and 3. Hence, the second gas 10 supplied from outside the groove portion 16 can form the air flow heading toward the peripheral side of the substrate stage 3 by bypassing the space 16b in the inside of the groove portion 16 without the reducing the air flow amount.

The larger the opening width w1 of the groove portion 16, the better the bypassing effect of the air flow. However, if the opening width w1 becomes equal to or more than, for example, 10 times the distance between the substrate 2 and the facing member 15, it can cause a disturbance for the formation of a gas curtain air flow due to the improvement of the air flow bypass effect, and the effect of foreign substance entry prevention is adversely reduced. That is, if the opening width w1 of the groove portion 16 is equal to or less than 10 times the distance h1 between the substrate 2 and the facing member 15, the air flow bypass effect can be improved without causing any disturbance in the formation of the gas curtain air flow. According to the examinations of the inventor, in order to more definitely improve the air flow bypass effect so as not to cause a disturbance during the formation of the gas curtain air flow, the opening width w1 of the groove portion 16 should be equal to or less than 2 times the distance h1 between the substrate 2 and the facing member 15.

Concerning the shape of the opening portion 16a of the groove portion 16, as shown as in Fig. 3, an outer-side edge portion 17 on the flow entry side or the flow exit side of the second gas 10 may be tilted toward the inner side. At this time, the inner-side edge portion of the groove portion 16 may be formed into a right angle within the range of the machining process. The tilt of the outer-side edge portion 17 may have a right angle surface structure or a round surface structure. The inflow second gas 10 can be easily drawn in and the outflow second gas 10 can be easily exhausted by tilting the outer-side edge portion 17.

In the above-described embodiment, since the first gas 13 is drawn in below the mold 4 by using the Couette flow which accompanies the movement of the substrate stage 3, the first gas nozzles 12 arranged on the side of the substrate stage 3 before the movement are used for the mold 4. Here, the plurality of first gas nozzles 12 may be arranged so as to surround the mold 4. For example, as shown in the state 1b of Fig. 1, after the imprint material 8 is conveyed immediately below the pattern portion 5 and the substrate stage 3 is stopped, all or some of the first gas nozzles 12 surrounding the mold 4 may be used to continue the supply of the first gas 13.

As described above, according to this embodiment, a gas curtain structure that can suppress the adherence of a foreign substance on the substrate without impeding the filling of the imprint space with the first gas can be implemented. Therefore, an imprint apparatus advantageous in accurate pattern formation can be provided.

A modification will be shown hereinafter. For example, as shown in Fig. 4, sprayers 18 connected to a third gas supply source 19 can be provided to supply gas to the groove portion 16. The groove portion 16 has a complicated shape compared to the surrounding facing member 15. Hence, if a foreign substance enters inside the groove portion, the foreign substance may remain. If the gas curtain is formed at the time of the first gas supply in a state in which the foreign substance is remaining in the groove portion 16, the possibility that the foreign substance will be moved by the second gas 10 flowing in the groove portion 16 and will adhere to the substrate 2 becomes high. Particularly, since the gas curtain air flow will not be formed in a state in which the substrate 2 is not positioned below the groove portion 16, the possibility that the foreign substance will enter inside the groove portion 16 is high. Hence, when the substrate 2 is not positioned below the groove portion 16, air is sprayed from the sprayers 18. As a result, entry of a foreign substance into the groove portion 16 can be prevented. In addition, even in a case in which the foreign substance has remained inside the groove portion 16, the foreign substance can be removed by spraying air from the sprayers 18.

(Embodiment of Method of Manufacturing Article)
An article manufacturing method according to an embodiment of the present invention is suitable for manufacturing an article, for example, a microdevice such as a semiconductor device or an element having a microstructure. The method of manufacturing an article according to this embodiment includes a step of forming a pattern of an imprint material on a substrate by using the above-described imprint apparatus (a step of performing an imprint process on the substrate), and a step of processing the substrate (the substrate having undergone the imprint process) on which the pattern has been formed in the above step. The manufacturing method further includes other well-known steps (for example, oxidation, film formation, deposition, doping, planarization, etching, resist removal, dicing, bonding, and packaging). When compared to the conventional methods, the method of manufacturing an article according to this embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of an article.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

This application claims the benefit of Japanese Patent Application No. 2015-245647, filed December 16, 2015, which is hereby incorporated by reference herein in its entirety.

Claims

An imprint apparatus that forms a pattern of an imprint material on a substrate by using a mold, comprising:
a facing member that is arranged around the mold and faces the substrate;
a first supply unit configured to supply a first gas between the mold and the substrate from a first supply port arranged between the mold and the facing member; and
a second supply unit configured to supply a second gas between the facing member and the substrate from a second supply port arranged in the facing member;
wherein the facing member includes, between the first supply port and the second supply port, a flow path configured to guide the second gas which flows from the second supply port toward the mold to bypass the space between the mold and the substrate.
The apparatus according to claim 1, wherein the flow path is a groove formed on a surface of the facing member which faces the substrate.
The apparatus according to claim 2, wherein the groove is formed to surround the mold and the first supply port.
The apparatus according to claim 2, wherein an opening width of the groove is larger than the distance between the facing member and the substrate.
The apparatus according to claim 4, wherein the opening width of the groove is not more than ten times the distance between the facing member and the substrate.
The apparatus according to claim 5, wherein the opening width of the groove is not more than twice the distance between the facing member and the substrate.
The apparatus according to any one of claims 4 to 6, wherein a section of the groove is formed to be a shape that has a width larger than the opening width.
The apparatus according to any one of claims 4 to 6, wherein an outer-side edge portion of an opening portion of the groove is tilted toward an inner side.
The apparatus according to any one of claims 1 to 6, further comprising a sprayer configured to spray a gas into the flow path.
The apparatus according to any one of claims 1 to 6, wherein the first gas is a condensable gas that is liquefied when the pressure in the space between the mold and the substrate rises.
A method of manufacturing an article, comprising:
forming a pattern on a substrate using an imprint apparatus; and
processing the substrate on which the pattern has been formed by the forming,
wherein the imprint apparatus is an imprint apparatus that forms a pattern of an imprint material on the substrate by using a mold and includes
a facing member that is arranged around the mold and faces the substrate,
a first supply unit configured to supply a first gas between the mold and the substrate from a first supply port arranged between the mold and the facing member, and
a second supply unit configured to supply a second gas between the facing member and the substrate from a second supply port arranged in the facing member, and
the facing member includes, between the first supply port and the second supply port, a flow path configured to guide the second gas which flows from the second supply port toward the mold to bypass the space between the mold and the substrate.