JP5332584B2 - Imprint mold, manufacturing method thereof, and optical imprint method - Google Patents

Description

  The present invention relates to an imprint mold, a manufacturing method thereof, and an optical imprint method. In particular, the present invention relates to an imprint mold incorporating an exposure light source, a manufacturing method thereof, and an optical imprint method.

  In recent years, it has been proposed to use an imprint method for forming a fine pattern in a manufacturing process of a semiconductor device, a display, a recording medium, a biochip, an optical device, or the like (see Non-Patent Document 1 and Non-Patent Document 2). .

  In the imprint method, a nanometer-level method is particularly referred to as a nanoimprint method. Hereinafter, the imprint method is also simply referred to as a nanoimprint method.

  In the imprint method, a mold called an imprint mold (also referred to as a template) in which a pattern corresponding to a negative / positive reversal image of a pattern to be finally transferred is formed on a resin, and in that state Pattern transfer is performed by curing the resin. At this time, a photoimprint method is known in which a photocurable resin is cured by irradiating exposure light (see Patent Document 1).

  In the imprint method, the peelability between the imprint mold and the resin pattern formed on the transfer substrate is extremely important. The peelability between the imprint mold and the resin pattern generated on the transfer substrate will be described with reference to FIGS. In general, the curing of the resin causes a resin shrinkage and generates a stress between the imprint mold and the resin pattern. For this reason, as shown in FIG. 6A, in the step of separating the imprint mold 62 and the resin 61 pattern after curing the resin 61, as shown in FIG. It is known that the resin 61 moves, and a part of the resin 61 pattern remains on the imprint mold 62 side as shown in FIG. .

  At this time, as shown in FIG. 6D, defects in the resin pattern during peeling frequently occur at the corners that are the boundary between the convex pattern part and the concave pattern part of the resin 61 pattern where stress is concentrated during peeling. Has been reported (see Non-Patent Document 3).

  Further, as a method for improving the peelability, a method has been proposed in which a fluoropolymer having a small surface energy is applied to the imprint mold surface as a release agent (see Patent Document 2).

However, even if the release agent is applied to the surface, if the release agent is repeatedly subjected to the imprint method, the release agent is gradually peeled off from the surface of the imprint mold, and the peelability between the imprint mold and the resin is lowered. .
JP 2000-194142 A JP 2002-283354 A Appl. phys. Lett. , Vol. 67, p3314 (1995) Nanoimprint Technology Thorough Diffraction Electric Journal Published November 22, 2004, p20-38 Y. Hirai, et al. J. et al. Vac. Sci. Technol. B21 (6), 2003

  In the present invention, the substrate does not require transparency to the exposure light, the exposure light source is built-in, the releasability between the imprint mold and the resin pattern is excellent, and the releasability is lowered even if the repeated light imprint method is performed. An imprint mold having no defect, a manufacturing method thereof, and an optical imprint method are provided.

The invention according to claim 1 of the present invention includes a substrate, a lower electrode formed on the substrate, a light emitting layer formed on the lower electrode and emitting light by organic electroluminescence , and an upper electrode formed on the light emitting layer. A protective layer formed on the upper electrode, a light-shielding pattern portion having an uneven portion having a convex portion formed of a material that does not transmit the emission wavelength emitted from the light emitting layer on the protective layer, and the lower electrode of the substrate And a conductive layer formed on a surface opposite to the surface on which the substrate is formed, and the substrate is an imprint mold characterized in that it does not transmit light having a wavelength emitted from the light emitting layer .

In the invention according to claim 2 of the present invention, a step is formed in a part of the outer peripheral portion of the surface of the substrate, a light emitting layer that emits light by organic electroluminescence is formed on the substrate, and a part is formed on the light emitting layer. The masked upper electrode is formed, a protective layer is formed on the entire surface including the upper electrode, the lower electrode, the light emitting layer and the upper electrode are insulated by masking, a resist is formed on the protective layer, the resist is patterned , and light emission is performed. A method for producing an imprint mold, wherein a pattern layer having a convex portion that does not transmit an emission wavelength emitted from the layer is formed, and the substrate does not transmit light having a wavelength emitted from the emission layer. It is what.

Invention of Claim 3 of this invention prepares the imprint mold of Claim 1 , applies a photocurable resin to a transfer substrate, joins an imprint mold and a transfer substrate, and applies joining force. The light imprinting method is characterized in that the light emitting layer formed on the imprint mold emits light, the imprint mold and the transfer substrate are peeled off, and a transfer unnecessary portion of the transfer substrate is removed.

  According to the present invention, the substrate does not need exposure light exposure, has a built-in exposure light source, is excellent in releasability between the imprint mold and the resin pattern, and the releasability is reduced even when repeated light imprinting is performed. It is possible to provide an imprint mold that does not occur, a manufacturing method thereof, and an optical imprint method.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiments, the same components are denoted by the same reference numerals, and redundant description among the embodiments is omitted.

  FIG. 1 is a schematic cross-sectional view showing an imprint mold 1 according to an embodiment of the present invention. As shown in FIG. 1, the imprint mold 1 according to the embodiment of the present invention includes a lower electrode 11, a light emitting layer 12, an upper electrode 13, a protective layer 14, and a light shielding pattern portion 15 on a substrate 10. Further, a conductive layer 16 is provided on the surface opposite to the lower electrode 11 formed on the substrate 10.

  For the substrate 10 of the imprint mold 1 according to the embodiment of the present invention, it is preferable to use a material having mechanical strength such as glass, insulation, and excellent dimensional stability, but the light transmission property is not limited. Good. The lower electrode 11 does not need to be a transparent material, and it is preferable to use a known electric wiring material such as aluminum. For the light emitting layer 12, it is preferable to use a material of a known organic electroluminescence (hereinafter, organic EL) light emitting layer. The upper electrode 13 may be a material that transmits light from the light emitting layer 12, but a transparent conductive material such as tin-doped indium oxide (ITO), zinc oxide, or tin oxide is preferable. The protective layer 14 is preferably made of a material that blocks the electrical continuity of the upper electrode 13 and simultaneously transmits the emitted light from the light emitting layer 12. The light shielding pattern portion 15 is suitable for pattern formation and needs to be a material that exhibits light shielding properties with respect to the wavelength emitted from the light emitting layer 12. The light shielding property is generally indicated by an optical density (OD: Optical Density). However, since it is used for the imprint mold 1, the provision of the uneven size of the light shielding pattern portion 15 is given priority. As will be described later, a material capable of obtaining a necessary optical density with respect to the exposure amount of the photo-curing resin 41 is appropriately selected. When durability, mechanical strength, and pattern formation by lithography are assumed, for example, metal materials such as Cr, Al, Ta, and Mo, and alloy materials containing these as main components are preferable.

  As the material of the protective layer 14, an appropriate material is selected in consideration of the etching selection ratio with the material selected in the light shielding pattern portion 15. As an example, the oxides or nitrides of Cr, Al, and Ta exemplified in the light shielding pattern portion 15 may be mentioned. The lower electrode 11, the light emitting layer 12, the upper electrode 13, the protective layer 14, and the light shielding pattern portion 15 can be formed by a sputtering method, a vacuum evaporation method, or the like. The conductive layer 16 is preferably formed using a conductive metal such as Cr by a sputtering method, a vacuum deposition method, or the like.

  Since the imprint mold 1 according to the embodiment of the present invention includes the exposure light source on the substrate 10 itself, it is necessary to prepare the imprint mold separately from the imprint mold, which is essential in the conventional imprint mold. The existing light source and the transparency of the substrate to the exposure light are not required.

  Electric power necessary for light emission of the light emitting layer 12 in the imprint mold 1 is supplied from a power source 20. Light emission as exposure light is performed from the entire surface of the light emitting layer 12, and is performed as indicated by an arrow shown in FIG. 1 because the light is blocked by the light shielding pattern portion 15. Further, a material that does not require exposure light to pass through the substrate 10 may be used.

  Hereinafter, the manufacturing method of the imprint mold 1 which concerns on Example 1 of this invention is demonstrated concretely using FIG. 2 (a)-(b) and FIG. 3 (a)-(b). FIGS. 2A to 2B and FIGS. 3A to 3B show a schematic top view and a schematic cross-sectional view, respectively. Naturally, the manufacturing method of the imprint mold 1 which concerns on Example 1 of this invention is not limited to the following Example 1. FIG.

  Here, light emission using the organic EL will be described with reference to FIG. In this example, an example of light emission using an organic EL is shown, but its basic structure is composed of three layers of a lower electrode 11, a light emitting layer 12, and an upper electrode 13. The organic EL includes a high molecular type and a low molecular type, and each is composed of a single layer or a plurality of laminated films. Although the structure will be described in the following description, the material of each layer is selected as appropriate depending on the photosensitive characteristics of the photo-curing resin 41 used for transfer of the imprint mold 1. The material to be used is selected and is not particularly mentioned.

  As shown in FIG. 2A, first, a quartz glass substrate 10 is prepared as a substrate 10 in which a step is provided on a part of the outer periphery of the surface. The step 33 may be formed by a known method such as a method using a chemical cutting action by a mechanical cutting method or a lithography method.

  Next, a metal such as Cr is formed on the entire surface of one side of the substrate 10 as the conductive layer 16. Next, Al or the like is formed on the entire surface of the opposite side of the conductive layer 16 as the lower electrode 11. In the low molecular structure formed on the lower electrode 11, for example, five layers of an electron injection layer, an electron transport layer, a light emitting layer 12, a hole transport layer, and a hole injection layer can be formed. Here, the light emitting layer 12 includes an electron injection layer, an electron transport layer, a hole transport layer, and a hole injection layer.

  On the other hand, in the polymer structure formed on the lower electrode 11, for example, a single layer structure for forming the light emitting layer 12 can be used.

Next, ITO, which is a transparent conductive material, was formed on the entire surface of the light emitting layer 12 except for some masking regions 31 as the upper electrode 13. Next, a transparent insulating material as a protective layer 14 was formed on the entire surface of the upper electrode 13 by using a sputtering method, a vacuum deposition method, a coating method, a printing method, or the like. Specific examples of the transparent insulating material include Ta _x O _y , Si _x O _y , and Al _x O _y (x and y are arbitrary real numbers).

The insulating relationship among the lower electrode 11, the light emitting layer 12, and the upper electrode 13 is ensured by the masking region 31 described above. Finally, Ta _x O _y was formed as a light shielding material for the light shielding pattern portion 15 on the entire surface by sputtering. The protective layer 14 described above is formed on the entire surface of the substrate, so that the etching selectivity between the sealing of the light emitting layer 30 and the light shielding pattern portion 16 described later is ensured over the entire surface of the substrate.

  Here, the lower electrode 11 and the upper electrode 13 will be described. A contact with the outside is necessary for the current supply. It is difficult to provide this contact on the light shielding pattern portion 15 surface side in terms of a gap distance from the transfer substrate 40 (described later). Further, it is difficult to pass through the substrate 10 and to be provided on the surface opposite to the light shielding pattern portion 15. Therefore, it is preferable to provide a contact on the outer peripheral side surface of the substrate 10. However, the film thickness of the lower electrode 11 and the upper electrode 13 is generally a thin film of about a micrometer or less. It is difficult to provide the electrode on the outer side surface of the substrate 10 with this film thickness. Therefore, a step 33 is provided on a part of the outer peripheral portion of the surface of the substrate 10 to secure a contact area on the side surface of the substrate 10.

Next, as shown in FIG. 2B, a resist was applied to the upper surface of Ta _x O _{y formed} as the light shielding pattern portion 15, and a resist pattern 17 was formed by exposure and development processing by an electron beam lithography method.

  Next, as shown in FIG. 3A, the light shielding pattern portion 15 was formed using a dry etching method using a mixed gas of chlorine and oxygen with the resist pattern 17 as a mask.

  Next, as shown in FIG. 3B, the resist pattern 17 is removed by dissolution with a chemical solution or ashing by oxygen plasma treatment. Thus, an imprint mold 1 having an uneven shape to be a mold pattern was obtained.

  Hereinafter, the optical imprint method according to Example 2 of the present invention will be specifically described with reference to FIGS. 4 (a) to 4 (b) and FIGS. 5 (a) to 5 (b). 4 (a)-(b) and FIGS. 5 (a)-(b) show a schematic top view and a schematic cross-sectional view, respectively.

  First, as shown in FIG. 4A, a photocurable resin 41 is applied on the transfer substrate 40. On the other hand, the imprint mold 1 produced in Example 1 is prepared.

  Next, as shown in FIG. 4B, the imprint mold 1 manufactured in Example 1 is held by the electrostatic chuck 50, and the transfer substrate 40 coated with the photocurable resin 41 is placed in the atmosphere or in a reduced pressure environment. The resin is bonded at the stage 42, current is supplied from the power source 20 to the lower electrode 11 and the upper electrode 13 for a predetermined time for resin curing, and the light emitting layer 12 emits light as indicated by an arrow in the figure to form a photocurable resin. 41 was cured. In joining, the joining force can be applied to the entire surface of the imprint mold 1 on the substrate 10 side through the electrostatic chuck 50. This solves the restriction that the conventional light imprint mold is a material that transmits the exposure light to transmit the exposure light, or at least the effective pattern region 32 (see FIG. 2B) is a space structure. This is advantageous for ensuring the flatness of the imprint mold 1.

  Next, as shown in FIG. 5A, the imprint mold 1 and the transfer substrate 40 were pulled back to the side opposite to the joining direction, and the imprint mold 1 and the transfer substrate 40 were peeled off.

  Next, as shown in FIG. 5B, a removal process is performed on the transfer substrate 40 with a chemical solution (developer) that dissolves the uncured portion 51 shielded from light by the resist pattern 17. At this time, it can be seen that the development of the uncured portion 51 can alleviate the action of the fixing stress to the imprint mold 1 due to the curing shrinkage of the photocurable resin 41 (see, for example, FIG. 6). From the above, the optical imprint method according to Example 2 of the present invention could be performed.

  In the optical imprint method using the imprint mold 1 according to the embodiment of the present invention, the exposure light source is provided on the substrate 10 itself, and the exposure light necessary for curing the photocurable resin 41 is irradiated only on the pattern portion, In addition, the substrate 10 does not need to be transmissive to exposure light. For this reason, the transparency with respect to the exposure light of a light source and a board | substrate which was essential in the conventional imprint mold and had to be prepared separately from the imprint mold becomes unnecessary. Furthermore, the degree of curing of the photocurable resin 41 on the convex surface on the imprint mold 1 side or the concave surface on the transfer substrate 40 side can be reduced, and the generation of stress due to resin shrinkage can be reduced. Therefore, it is possible to suppress the occurrence of a resin pattern defect in the step of peeling the imprint mold 1 and the resin pattern.

  The imprint mold of the present invention is expected to be used in a wide range of fields where fine pattern formation is desired. For example, semiconductor devices, optical components such as optical waveguides and diffraction gratings, recording devices such as hard disks and DVDs, life It is expected to be used in the manufacturing process of products such as biochips used for DNA analysis and the like in the science field, diffusion plates and light guide plates used for image / video displays in the display field and the like.

It is a schematic sectional drawing which shows the imprint mold which concerns on embodiment of this invention. (A) And (b) is a schematic sectional drawing which shows the manufacturing process of the imprint mold which concerns on Example 1 of this invention. (A) And (b) is a schematic sectional drawing which shows the manufacturing process of the imprint mold which concerns on Example 1 of this invention. (A) And (b) is a schematic sectional drawing which shows the process of the optical imprint mold method which concerns on Example 2 of this invention. (A) And (b) is a schematic sectional drawing which shows the process of the optical imprint mold method which concerns on Example 2 of this invention. (A)-(d) is a schematic sectional drawing which shows generation | occurrence | production of a defect in the peeling process of an imprint mold.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Imprint mold, 10 ... Board | substrate, 11 ... Lower electrode, 12 ... Light emitting layer, 13 ... Upper electrode, 14 ... Protective layer, 15 ... Light-shielding pattern part, 16 ... Conductive layer, 17 ... Resist pattern, 20 ... Power supply, DESCRIPTION OF SYMBOLS 31 ... Masking area | region, 32 ... Effective pattern area | region, 33 ... Level difference, 40 ... Transfer substrate, 41 ... Photocuring resin, 42 ... Stage, 50 ... Electrostatic chuck, 51 ... Uncured part, 60 ... Transfer substrate, 61 ... Resin 62 ... Imprint mold

Claims (3)

A substrate,
A lower electrode formed on the substrate;
A light emitting layer formed on the lower electrode and emitting light by organic electroluminescence ;
An upper electrode formed on the light emitting layer;
A protective layer formed on the upper electrode;
A light-shielding pattern portion having a concavo- convex portion having a convex portion formed of a material that does not transmit the emission wavelength emitted from the light-emitting layer on the protective layer;
A conductive layer formed on the surface of the substrate opposite to the surface on which the lower electrode is formed;
Equipped with a,
The imprint mold, wherein the substrate does not transmit light having a wavelength emitted from the light emitting layer . Form a step in part of the outer periphery of the surface of the substrate,
On the substrate, a lower electrode and a light emitting layer that emits light by organic electroluminescence are formed,
Forming an upper electrode partially masked on the light emitting layer;
Forming a protective layer on the entire surface including the upper electrode;
Insulating the lower electrode, the light emitting layer and the upper electrode by the masking,
Forming a resist on the protective layer;
Patterning the resist to form a pattern layer having a convex portion that does not transmit the emission wavelength emitted from the light emitting layer ,
Forming a conductive layer on the surface of the substrate opposite to the surface on which the lower electrode is formed;
The method for producing an imprint mold, wherein the substrate does not transmit light having a wavelength emitted from the light emitting layer . Prepare the imprint mold according to claim 1,
Apply photo-curing resin to the transfer substrate,
Joining the imprint mold and the transfer substrate, while emitting a light emitting layer formed on the imprint mold while applying a bonding force ,
Peel off the imprint mold and the transfer substrate,
An optical imprint method comprising removing a transfer unnecessary portion of the transfer substrate.