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Researchers Submit Patent Application, "Pattern Transferring Apparatus and Pattern Transferring Method", for Approval

June 25, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors KASUMI, Kazuyuki (Utsunomiya-shi, JP); OTA, Hirohisa (Kawagoe-shi, JP); KAWAKAMI, Eigo (Utsunomiya-shi, JP); NAKAMURA, Takashi (Edogawa-ku, JP); TOKITA, Toshinobu (Yokohama-shi, JP), filed on November 27, 2013, was made available online on June 12, 2014.

The patent's assignee is Canon Kabushiki Kaisha.

News editors obtained the following quote from the background information supplied by the inventors: "The present invention relates to a so-called nanoimprint lithography apparatus which transfers a pattern formed on a mold to an object such as a resin material by bringing the mold into contact with the object.

"A so-called nanoimprint lithography technique has been proposed for manufacturing various devices having fine patterns including semiconductor chips such as ICs and LSIs, display devices such as liquid crystal panels, detecting devices such as magnetic heads, image-pickup devices such as CCDs, and MEMS (Micro Electro-Mechanical Systems)

"The nanoimprint lithography involves pushing a mold (also referred to as an original plate or a template) having a fine pattern formed thereon onto a wafer coated with a resin material (a resist) to transfer the pattern to the resist. (see S. Y. Chou, et al., Science, vol. 272, p. 85-87, 5 Apr. 1996).

"Propositions of the nanoimprint lithography include a transfer method in which polymer used as a resist is heated to a glass transition temperature or higher to increase the fluidity to facilitate the flow of the resist at the time of transfer (a heat cycle method), and a transfer method in which an ultraviolet-curing resin (a UV-curing resin) is used as a resist and is irradiated with light while it is in contact with a transparent mold to achieve curing (called a photo-curing method or a UV-curing method). The photo-curing method is often used in manufacturing the semiconductor device.

"FIGS. 15(1) to 15(3) show a transfer process in the photo-curing method.

"A first step (1) is a stamping step. A mold M made of a material (for example, quartz) which passes ultraviolet light is pushed onto a resist UVR made of UV-curing resin coating a substrate (a wafer) W. This causes the UV-curing resin to flow along a pattern formed on the mold.

"A second step (2) is a curing step. With the mold M pushed onto the resist UVR on the substrate W, ultraviolet light UV is applied thereto. As a result, the resist is cured in the same shape as the pattern on the mold M.

"A third step (3) is a mold release step. The mold M is released from the cured resist UVR. After the mold release, the resist UVR having the shape of the pattern is left on the substrate W. In this manner, the pattern is transferred to the substrate.

"In manufacturing the semiconductor device, the abovementioned transfer process is generally repeated on a single substrate to transfer a plurality of patterns all over the substrate.

"RIE processing is performed to remove the base of the transferred resin (resist) pattern. The resulting pattern is equivalent to a resist pattern provided by transfer in a conventional photolithography apparatus. The subsequent steps are the same as those in a conventional LSI manufacturing process.

"The stamping step and the curing step can be performed faster by speeding up the mechanical operation and applying illumination light with higher illuminance, respectively. However, the mold release step is not easily performed quicker simply by speeding up the mechanical operation since the fine pattern may be damaged by the friction between the mold and the cured resist. To address this, the mold is subjected to mold release coating to improve the mold release property (see U.S. Pat. No. 6,309,580).

"The resist, however, is not always convenient for the mold release depending on the conditions of device manufacturing. Specifically, even when typical mold release coating is performed on the mold, the mold release property cannot be improved sufficiently in some types of resists."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "It is an object of the present invention to provide a pattern transferring apparatus and a transfer method which can prevent damage to a transferred pattern and realize fast mold release regardless of the type of resist.

"According to an aspect, the present invention provides a pattern transferring apparatus which transfers a pattern formed on a mold to an object by bringing the mold into contact with the object. The pattern transferring apparatus has a deformer which causes deformation in the mold for releasing the mold from the object.

"According to another aspect, the present invention provides a pattern transferring apparatus which transfers a pattern formed on a mold to a photo-curing resin by bringing the mold into contact with the photo-curing resin and applying light thereto to cure the photo-curing resin. The pattern transferring apparatus has an optical system which applies light at an irradiation light intensity to a non-transfer area other than a transfer area where the pattern is to be transferred in the photo-curing resin, the irradiation light intensity being different from an irradiation light intensity of light applied to the transfer area.

"According to yet another aspect, the present invention provides a pattern transferring apparatus which transfers a pattern formed on a mold to an object by bringing the mold into contact with the object. The pattern transferring apparatus has an actuator which generates force in the mold in a direction in which the mold is released from the object.

"According to a further aspect, the present invention provides a method of transferring a mold pattern, having the steps of transferring a pattern formed on a mold to an object by bringing the mold into contact with the object, and causing deformation in the mold for releasing the mold from the object.

"According to a still further aspect, the present invention provides a method of transferring a mold pattern, having the steps of transferring a pattern formed on a mold to a photo-curing resin by bringing the mold into contact with the photo-curing resin and applying light thereto to cure the photo-curing resin, and applying light at an irradiation light intensity to a non-transfer area other than a transfer area where the pattern is to be transferred in the photo-curing resin, the irradiation light intensity being different from an irradiation light intensity of light applied to the transfer area.

"According to a yet further aspect, the present invention provides a method of transferring a mold pattern, having the steps of transferring a pattern formed on a mold to an object by bringing the mold into contact with the object, and driving an actuator which is provided for the mold and generates force in the mold in a direction in which the mold is released from the object.

"Other objects and features of the present invention will become readily apparent from the following description of the preferred embodiments with reference to accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

"FIG. 1 is a schematic diagram showing the structure of a nanoimprint apparatus which is Embodiment 1 of the present invention.

"FIG. 2 is a flow chart showing a pattern transfer process with the nanoimprint apparatus of Embodiment 1.

"FIG. 3 is a schematic diagram showing the structure of part of the nanoimprint apparatus of Embodiment 1.

"FIG. 4 is a perspective view showing the structure of part of the nanoimprint apparatus of Embodiment 1.

"FIG. 5 is a flowchart showing a mold release process with the nanoimprint apparatus of Embodiment 1.

"FIG. 6 is a diagram for explaining a scribe line.

"FIG. 7 is a schematic diagram showing the structure of part of a nanoimprint apparatus which is Embodiment 2 of the present invention.

"FIG. 8 is a schematic diagram showing the structure of part of a nanoimprint apparatus which is Embodiment 3 of the present invention.

"FIG. 9 is a schematic diagram showing the structure of part of a nanoimprint apparatus which is Embodiment 4 of the present invention.

"FIG. 10 is a schematic diagram showing the structure of part of a nanoimprint apparatus which is Embodiment 5 of the present invention.

"FIGS. 11A and 11B are explanatory diagrams showing the curing of a resist in Embodiment 5.

"FIG. 12 is a schematic diagram showing the structure of part of a nanoimprint apparatus which is Embodiment 6 of the present invention.

"FIGS. 13A and 13B are schematic diagrams showing the structure of part of a nanoimprint apparatus which is Embodiment 7 of the present invention.

"FIG. 14 is a flow chart for explaining a method of manufacturing a device (Embodiment 8) with the nanoimprint apparatus of each of Embodiments 1 to 7.

"FIGS. 15(1) to 15 (3) are diagrams for explaining steps in UV-curing nanoimprint."

For additional information on this patent application, see: KASUMI, Kazuyuki; OTA, Hirohisa; KAWAKAMI, Eigo; NAKAMURA, Takashi; TOKITA, Toshinobu. Pattern Transferring Apparatus and Pattern Transferring Method. Filed November 27, 2013 and posted June 12, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=5536&p=111&f=G&l=50&d=PG01&S1=20140605.PD.&OS=PD/20140605&RS=PD/20140605

Keywords for this news article include: Electronics, Semiconductor, Canon Kabushiki Kaisha.

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Source: Electronics Newsweekly


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