Patent Application
20160023380
1. Field of the Invention
The present invention relates to an imprint method, an imprint apparatus, and an article manufacturing method.
2. Description of the Related Art
The imprint technology, which allows a nanoscale fine pattern to be transferred, has begun to be utilized as one of the nanolithography technologies for mass-producing magnetic storage media, semiconductor devices, or the like. In the imprint method, a fine pattern is formed on a substrate such as a silicon wafer, glass plate, or the like using a mold on which the fine pattern has been formed with an apparatus such as an electron beam lithography apparatus or the like. This fine pattern is formed by applying a resin on the substrate and then curing the resin with the mold having the pattern formed thereon being pressed on the substrate through the resin.
One important characteristic for accurately forming a pattern on a substrate to be processed by the imprint method is releasability (mold releasability) when a mold having a pattern formed thereon is released from a resin, for example. One factor having an influence on the releasability is, for example, the adhesive strength between a mold and a resin material or transfer layer on a substrate. In order to improve the releasability, the adhesive strength needs to be reduced. Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2006-528088 discloses a method for improving the releasability by including a material for reducing adhesive strength, which has a higher affinity to a mold than a resin, into the resin that is applied on a substrate, and then pressing the mold and the resin against each other to bring the material for reducing adhesive strength into contact with the mold. Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2006-528088 also describes a method for undercoating a material for reducing adhesive strength on a mold by bringing an undercoated substrate, on which the material for reducing adhesive strength is undercoated, into contact with the pattern of the mold repeatedly.
However, Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2006-528088 has no specific description for the imprint method including a process for reducing adhesive strength when the undercoated substrate is used and an imprint process on the substrate to be processed, that is, regarding a step for determining whether or not a process for reducing adhesive strength on a mold is required after pressing a pattern on the substrate to be processed, or the like. In order to improve the releasability without reducing the productivity due to using the undercoated substrate, the efficiency of the work needs to be improved by performing the step for determining whether or not the process for reducing adhesive strength is required.
The present invention provides, for example, an imprint method for improving the releasability without reducing the productivity.
According to an aspect of the present invention, an imprint method for performing an imprint process in which an imprint material on a substrate to be patterned is brought into contact with a pattern of a mold to form a pattern of the imprint material, the imprint method comprising a step of determining whether or not a process for reducing adhesive strength for reducing adhesive strength between the imprint material and the pattern of the mold is required, wherein, if the determination step determines that the process for reducing adhesive strength is required, the process for reducing adhesive strength is performed by bringing a material for reducing adhesive strength on a substrate for reducing adhesive strength, which is different from the substrate to be patterned, into contact with the pattern of the mold, and then an imprint process is performed, and wherein if the determination step determines that the process for reducing adhesive strength is not required, the process for reducing adhesive strength is not performed and an imprint process is performed.
Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).
Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings.
Firstly, a configuration of an imprint apparatus according to a first embodiment of the present invention will be described.
The substrate holding mechanism 108 includes a substrate suction mechanism and a substrate holding chuck. The substrate holding chuck is composed of one or more region(s), and each region is provided with the substrate suction mechanism. The filling camera 114 can take a photograph of a first pattern portion 301 from the side of a mask holding mechanism 110, and can record the process in which the photocurable resin 201 is filled between the mask 102 and the substrate 103. The images recorded by the filling camera 114 are stored on a memory device (not shown). The relative positions between the mask-side mark 306 and the mark formed on the substrate 103 and between the mask-side mark 306 and the substrate-stage-side mark 115 are measured with an optical position detector as disclosed in Japanese unexamined patent application publication (Translation of PCT Application) No. 2008-509825, for example. In particular, the measurement using the Moire signals that are generated from the both sides are useful because a high measuring precision can be obtained with a simple optical system. Furthermore, since the Moire signals described above can be detected without a high precision optical system, a scope having a small resolving power (small NA) can be employed, and a plurality of scopes can be arranged. This allows, for example, a configuration by which the marks on the four corners of a shot can be measured at the same time.
As shown in
Next, an imprint method for performing an imprint process in which an imprint material on a substrate is brought into contact with a pattern of a mold to form a pattern of the imprint material will be described with reference to
The imprint method according to the present embodiment further includes a process for reducing adhesive strength between an imprint material and a pattern of a mold in addition to the above-described imprint method. The specific process will be described below. Here, a substrate for reducing adhesive strength used in the process for reducing adhesive strength will be described. The releasability can be improved by exposing the mask 102 to an adjustment mixture containing an additive agent for reducing surface energy (material for reducing adhesive strength). The releasability can also be improved by bringing the photocurable resin 201 including the adjustment mixture containing an additive agent for reducing surface energy into contact with the mask 102. The substrate for reducing adhesive strength may be made of silicon, plastic, gallium arsenide, mercury telluride, or even a complex material thereof. The substrate for reducing adhesive strength is shaped so as to be mountable on the substrate stage 104 in a manner similar to the substrate 103 (substrate to be patterned) that is a common substrate for production. The adjustment mixture, which contains an additive agent for reducing surface energy, or the photocurable resin 201, which includes the adjustment mixture containing an additive agent for reducing surface energy, may be spin-coated on the surface of the substrate in advance for reducing adhesive strength. The releasability can be improved using the substrate for reducing adhesive strength precoated with the photocurable resin 201 including the adjustment mixture containing more additive agent for reducing surface energy more than in the substrate for production without changing the characteristic of the photocurable resin 201 for production.
The mask 102 may be made of any material including, but not limited to, fused silica, an organic polymer, or a metal. As shown in
Here, a transfer sequence (imprint method) including a process for reducing adhesive strength according to the present embodiment will be described with reference to
For the step S604, transfer conditions such as a number of transfer shots, a size of transfer shots, a filling time, an exposure time, or an applying pattern of the curable resin are specified independently of the conditions for the step S607. However, the transfer sequence is the same as the one for the step S607. Note that when the photocurable resin 201 including the adjustment mixture containing an additive agent for reducing surface energy is spin-coated on the substrate for reducing adhesive strength in advance, the photocurable resin 201 is not applied by the applying mechanism 106. A number of transfer shots, a filling time, an exposure time, or an applying pattern of the curable resin is specified as the recipe for reducing adhesive strength.
In the step S602, when it is determined that the step S604 is not required, the step S604 is not performed and the process proceeds to “conveying-in substrate for production” (step S606). In contrast, when it is determined that the step S604 is required, “conveying-in substrate for reducing adhesive strength” (step S603) is performed. In the step S603, when the substrate for reducing adhesive strength is not mounted on the substrate holding mechanism 108, the substrate conveyance unit 501 conveys the substrate for reducing adhesive strength that is stored in the substrate storage device 504 into the substrate holding mechanism 108. In the step S604, the process is performed on one or more shot(s) in the substrate for reducing adhesive strength by bringing the pattern of the mask 102 into contact with the photocurable resin 201 including the adjustment mixture containing an additive agent. Then, “conveying-out substrate for reducing adhesive strength” (step S605) is performed. In the step S605, the substrate conveyance unit 501 conveys-out the substrate to the substrate storage device 504. The information about the transfer area on which the step S604 has been performed is recorded for each substrate for reducing adhesive strength. For example, as shown in
In the step S606, the substrate conveyance unit 501 conveys-out the substrate 103 (substrate to be patterned) in the substrate holding mechanism 108 to the substrate storage device 504 or the substrate carrier 506. Then, the substrate conveyance unit 501 conveys-in the substrate 103 in the substrate carrier 506 to the substrate holding mechanism 108. In the step S607, the process is performed under the condition(s) specified in the recipe for production by the imprint method as described with reference to
As described above, according to the present embodiment, the imprint method that can improve the releasability without reducing the productivity can be provided. Note that although the step S602 is performed every time after the step S608 in the transfer sequence, it may be performed in the step S607, in which the substrate for production is replaced with the substrate for reducing adhesive strength once, and then the step S604 may be performed.
Next, an imprint method according to a second embodiment of the present invention will be described. A difference between the first embodiment and the present embodiment is how to convey a substrate.
A substrate conveyance unit 801 is composed of a first substrate conveyance arm 803a and a second substrate conveyance arm 803b that can be driven in the vertical direction, rotated and extended in the horizontal direction, and of a substrate conveyance hand 802 that can be rotated in the horizontal direction. The substrate conveyance hand 802, which includes a suction mechanism on the top surface, can suction the substrate 103. A substrate carrier 805 that holds several pieces of substrates 103 is conveyed into/out of a substrate conveying-in/out mechanism 804. A substrate conveying-in entrance 806 is a substrate holding mechanism that conveys-in a piece of substrate 103 from the substrate supply system 808 adjacent thereto. A substrate conveying-out exit 807 is a substrate holding mechanism that conveys-out a piece of substrate 103 to the substrate supply system 808 adjacent thereto. The substrate conveyance hand 802 can convey the substrates 103 one by one into/out of the substrate stage 104, the substrate conveying-in/out mechanism 804, the substrate conveying-in entrance 806, and the substrate conveying-out exit 807.
The substrate supply system 808 has a mechanism (not shown) for holding several pieces of substrates 103 and a mechanism (not shown) for spin-coating the photocurable resin 201 including the adjustment mixture containing an additive agent for reducing surface energy on the substrate for reducing adhesive strength. The substrate supply system 808 can convey the substrates for reducing adhesive strength or the substrates 103 (substrate to be patterned) one by one into/out of the substrate conveying-in entrance 806 or the substrate conveying-out exit 807 by the substrate conveyance unit 801. In the present embodiment, the substrate for reducing adhesive strength is supplied through the substrate conveying-in entrance 806. Thus, the substrate for reducing adhesive strength is conveyed through a path different from a conveyance path for the substrate for production (substrate to be patterned).
Here, a transfer sequence (imprint method) including a process for reducing adhesive strength according to the present embodiment will be described with reference to
In the step S904, transfer conditions such as a number of transfer shot, a size of transfer shot, a filling time, an exposure time, or an applying pattern of the curable resin are specified independently of the conditions for the step S907. However, the transfer sequence is the same as the one for the step S907. Note that, when the substrate for reducing adhesive strength is spin-coated in advance with the photocurable resin 201 including the adjustment mixture containing an additive agent for reducing surface energy, the photocurable resin 201 is not applied by the applying mechanism 106. A number of transfer shots, a filling time, an exposure time, or an applying pattern of the curable resin are specified as the recipe for reducing adhesive strength.
When it is determined that the step S904 is required, “conveying-in substrate for reducing adhesive strength” (step S903) is performed. In the step S903, when the substrate for reducing adhesive strength is mounted on the substrate holding mechanism 108, it is conveyed-out to the substrate conveying-out exit 807, and while the substrate 103 (substrate to be patterned) is mounted thereon, it is conveyed-out to a substrate carrier 805 by the substrate conveyance unit 801. Next, the substrate for reducing adhesive strength that is held at the substrate conveying-in entrance 806 is conveyed into the substrate holding mechanism 108 by the substrate conveyance unit 801. After the substrate for reducing adhesive strength is obtained by the substrate conveyance unit 801 from the substrate conveying-in entrance 806, the apparatus reports to the substrate supply system 808 that the substrate conveying-in entrance 806 has become empty. After being reported, the substrate supply system 808 supplies the substrate for reducing adhesive strength to the substrate conveying-in entrance 806. In the step S904, the process is performed on one or more of shot region(s) in the substrate for reducing adhesive strength. The information about shot position(s) to be used for transfer is reported together with the information about the individual identification number of the substrate 103 from the substrate supply system 808. The information about the transfer area on which the step S904 has been performed is reported to the substrate supply system 808 together with the information about the individual identification number of the substrate 103. The information about the transfer area includes, for example, the shot center (X,Y) of each of the used shots 701 as well as the X size and Y size of the shot as shown in
In the step S907, the process is performed under the condition(s) specified in the recipe for production by the imprint method as described with reference to
As described above, the present embodiment provides the same effects as the first embodiment. Furthermore, in the present embodiment, even when the time from the process for spin-coating the substrate for reducing adhesive strength with a photocurable resin to the transfer process for reducing adhesive strength is limited for example, the releasability can be improved by the above-described substrate conveyance mechanism without reducing the productivity. Note that although the step S902 is performed every time after the step S908 in the transfer sequence, it may be performed in the step S907, in which the substrate for production is replaced with the transfer substrate for reducing adhesive strength once, and then the step S904 may be performed.
Next, an imprint method according to a third embodiment of the present invention will be described. The present embodiment includes two transfer systems (first and second transfer systems), and is different from the first and second embodiments in terms of how a substrate is conveyed.
A substrate conveyance unit 1003 is composed of a first substrate conveyance arm 1005a and a second substrate conveyance arm 1005b that can be driven in the vertical direction, rotated and extended in the horizontal direction, and of a substrate conveyance hand 1004 that can be rotated in the horizontal direction. The substrate conveyance hand 1004, which includes a suction mechanism on the top surface, can suction the substrate 103. A substrate storage device 1006, which includes one or more slot(s), can store one or more substrate(s) 103. A substrate carrier 1008 that holds several pieces of substrate 103 is conveyed into/out of a first substrate conveying-in/out mechanism 1007a and a second substrate conveying-in/out mechanism 1007b. The substrate conveyance hand 1004 can convey-in/out the substrates 103 one by one to a first substrate stage 1001, a second substrate stage 1002, and any slot of the substrate storage device 1006. Furthermore, the substrate storage device 1006 can convey the substrates 103 one by one into/out of any slot of the substrate carrier 1008 attached to the first substrate conveying-in/out mechanism 1007a or the second substrate conveying-in/out mechanism 1007b. In the present embodiment, the substrate for reducing adhesive strength is stored in the substrate storage device 1006. Therefore, the substrate for reducing adhesive strength is conveyed through a path different from a conveyance path for the substrate for production (substrate to be patterned). Use of the same substrate for reducing adhesive strength for the first and second transfer systems allows more reduction in the number of the substrates for reducing adhesive strength that are stored in the substrate storage device 1006 compared with the case where their dedicated substrates for reducing adhesive strength are used for each of the first and second transfer systems.
In order to store the substrate for reducing adhesive strength in the substrate storage device 1006, the substrate carrier 1008 that holds the substrate for reducing adhesive strength is conveyed into the first substrate conveying-in/out mechanism 1007a or the second substrate conveying-in/out mechanism 1007b. Then, the substrate conveyance hand 1004 conveys the substrate for reducing adhesive strength into an empty slot of the substrate storage device 1006. When several pieces of substrate for reducing adhesive strength are stored in the substrate storage device 1006, the substrate conveyance hand 1004 conveys the substrates for reducing adhesive strength one by one into empty slots of the substrate storage device 1006 several times. When the used substrate for reducing adhesive strength is conveyed outside the apparatus, the substrate carrier 1008 having an empty slot is conveyed into the first substrate conveying-in/out mechanism 1007a or the second substrate conveying-in/out mechanism 1007b. Then, the substrate conveyance hand 1004 conveys-out the used substrate for reducing adhesive strength to an empty slot of the substrate carrier 1008. When several pieces of substrate for reducing adhesive strength are conveyed-out to the substrate carrier 1008, the substrate conveyance hand 1004 conveys the substrates for reducing adhesive strength one by one into empty slots of the substrate carrier 1008 several times.
Here, a transfer sequence (imprint method) including a process for reducing adhesive strength according to the present embodiment will be described with reference to
In order to determine whether or not the step S1107 is performed in the transfer system to which the substrate has been conveyed, “determination of necessity of process for reducing adhesive strength at substrate conveyance destination” (step S1103) is performed. In the step S1103, the upper limit of the number of times that the mask 102 mounted on the first and second transfer systems is transferred to the substrate 103 (substrate to be patterned) is determined in advance, and when the time exceeds the upper limit, it is determined that the step S1107 is required. The criterion for the step S1103 described above is only one example and does not limit the use of other criteria. For example, the step S1103 may use other criteria such as whether or not the total time of filling when the mask 102 is transferred to the substrate 103 exceeds the predetermined time, or whether or not the number of the particles 401b observed by the filling camera 114 exceeds the predetermined number.
Here, one example will be taken and described below contemplating that the substrate 103 (substrate to be patterned) is conveyed into a first substrate holding mechanism 1002a and that the step S1107 is required. In “conveying-in substrate for reducing adhesive strength” (step S1104), when the substrate for reducing adhesive strength is not mounted on the first substrate holding mechanism 1002a, the substrate conveyance unit 1003 conveys-out the substrate to the substrate carrier 1008. Next, the substrate conveyance unit 1003 conveys the substrate for reducing adhesive strength that is stored in the substrate storage device 1006 into the first substrate holding mechanism 1002a. When a usable substrate for reducing adhesive strength is mounted on a second substrate holding mechanism 1002b, after the substrate for reducing adhesive strength has been used in the second transfer system, the substrate conveyance unit 1003 conveys it out to the second substrate holding mechanism 1002b. Then, it is conveyed into the first substrate holding mechanism 1002a. Here, when the substrate for reducing adhesive strength is conveyed out of the second substrate holding mechanism 1002b, the information about the transfer area as described below is updated based on the used result in the second transfer system. When the substrate for reducing adhesive strength is conveyed into the first substrate holding mechanism 1002a, the information about the individual identification number for identifying the type of the substrate is also reported to the first transfer system.
In the first transfer system, after the substrate has been conveyed into the first substrate holding mechanism 1002a, “determination of substrate type” (step S1106) is performed based on the information about the individual identification number. As a result of the step S1106, when it is determined to be the substrate for reducing adhesive strength, the step S1107 is performed, whereas, when it is determined to be the substrate for production, the step S1108 is performed. In the step S1107, transfer conditions such as a number of transfer shots, a size of a transfer shot, a filling time, an exposure time, or an applying pattern of the curable resin are specified independently of the conditions for the step S1108. However, the transfer sequence is the same as the one for the step S1108. A number of transfer shots, a filling time, an exposure time, or an applying pattern of the curable resin are specified as the recipe for reducing adhesive strength. After the step S1107 has been performed on one or more of shot region(s) in the substrate for reducing adhesive strength in this step, the substrate conveyance unit 1003 conveys-out the substrate for reducing adhesive strength to the substrate storage device 1006. The information about the transfer area on which the step S1107 has been performed is recorded for each substrate for reducing adhesive strength. The information about the transfer area includes, for example, the shot center (X,Y) of each of the used shots 701 as well as the X size and Y size of the shot as shown in
In “conveying substrate for production” (step S1105), the substrate conveyance unit 1003 conveyed-out the substrate 103 in the first substrate holding mechanism 1002a to a substrate storage device 1006 or the substrate carrier 1008. Next, the substrate conveyance unit 1003 conveys-in the substrate 103 in the substrate conveyance unit 1003 to the substrate holding mechanism 108. In the step S1108, the process is performed under the conditions specified in the recipe for production by the imprint method as described with reference to
As described above, the present embodiment provides the same effects as the first and second embodiments. Furthermore, in the present embodiment, use of the imprint apparatus including more than one set of transfer mechanisms and substrate stages can improve the releasability without reducing the productivity. Note that, although the step S1103 is performed every time after the step S1105, it may be performed in the step S1108, in which the substrate for production is replaced with the transfer substrate for reducing adhesive strength once, and then the step S1107 may be performed.
A method for manufacturing a device (semiconductor integrated circuit element, liquid display element, or the like) as an article may include a step of forming a pattern on a substrate (wafer, glass plate, film-like substrate, or the like) using the imprint apparatus described above. Furthermore, the manufacturing method may include a step of etching the substrate on which a pattern has been formed. When other articles such as a patterned medium (storage medium), an optical element, or the like are manufactured, the manufacturing method may include another step of processing the substrate on which a pattern has been formed instead of the etching step. The device manufacturing method of the present embodiment has an advantage, as compared with a conventional method, in at least one of 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. 2014-148752 filed Jul. 22, 2014, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014-148752 | Jul 2014 | JP | national |
