JP2009282278A - Method for processing photoresist layer and method for manufacturing curved surface member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for processing a photoresist layer and a method for manufacturing a curved surface member by which the scanning time of a laser beam on a photoresist layer formed on a curved surface can be shortened. <P>SOLUTION: The method for processing a photoresist layer and the method for manufacturing a curved surface member include: a preparation step of preparing a plurality of curved raw materials each having a curved surface 61a having a circular arc in a cross-sectional view (cylindrical lens 61); a resist forming step of forming a photoresist layer 62 on the curved surface 61a of the curved raw material; a setting step of placing the curved surface raw material to a support member 2 so as to align each curved surface 61a of the plurality of curved raw materials along a single circle C; and an exposure step of irradiating the photoresist with a laser beam from a head 3 while rotating the support member 2 around the center axis 2A of the circle C as well as moving the head 3 in the direction of the center axis 2A. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for processing a photoresist layer in which a pattern is formed by exposure to laser light, and a method for manufacturing a curved member using this processing method.

  In general, as a method for forming a submicron-order concavo-convex pattern, the photoresist layer formed on the substrate is subjected to EB (electron beam) drawing, mask exposure, etc., and then developed to develop a fine pattern in the photoresist layer. A method of forming a simple hole is known (see, for example, Patent Document 1).

JP 2005-217390 A

  However, EB drawing, mask exposure, and the like have problems that extremely expensive equipment is required and productivity is low.

  In response to this problem, the inventor scans a laser beam in a predetermined pattern with respect to a photoresist layer (a photoresist layer in which a hole is formed only by laser beam irradiation) capable of changing the shape of the heat mode. Therefore, a method for forming a concave-convex pattern on the order of submicron has been devised. This method has the advantage that the equipment can be simplified and the productivity is high because the development step is unnecessary.

  However, when a plurality of linear line patterns are formed in parallel with a substrate having a photoresist layer by this method, after forming one line pattern with laser light on an XY table, Since it is necessary to repeat the operation of forming a new line pattern with the laser light after shifting by the width of, there is a problem that the processing time becomes long. Specifically, for example, in the case of forming a line pattern at a 0.2 μm pitch on a photoresist layer formed on a 20 mm square substrate, it is necessary to form 100,000 line patterns. There is a problem that the processing time is about 14 hours even if the time taken for one cycle from the formation of one line pattern to the formation start position of the next line pattern is 0.5 seconds.

  Furthermore, in the case where fine irregularities are formed by irradiating a laser beam on a photoresist layer formed on a curved surface such as a lens surface, as described above, the laser beam is moved by an XY table. Since the laser beam has to be moved along the curved surface in the optical axis direction, there is a problem that the process is further complicated and the processing time is increased. Specifically, for example, in the case where a photoresist layer formed on the curved surface of a cylindrical lens shaped like a part of a cylinder is scanned in the Y direction while shifting the laser beam by a predetermined pitch in the X direction. When scanning in the Y direction, the laser beam must be moved along the curved surface in the optical axis direction, which takes time. In addition, when scanning the photoresist layer formed on the curved surface of the lens shaped like a part of a sphere in the Y direction while shifting the laser beam by a predetermined pitch in the X direction, each position in the X direction Since the gap between the laser head and the machined surface differs depending on the type, the control becomes more complicated and takes time.

  Therefore, an object of the present invention is to provide a method for processing a photoresist layer and a method for manufacturing a curved member that can shorten the scanning time of laser light onto the photoresist layer formed on the curved surface.

  In order to solve the above problems, a method for processing a photoresist layer and a method for producing a curved member according to the present invention include a preparation step of preparing a plurality of curved materials having a curved surface having a circular arc shape in cross section, A resist forming step of forming a photoresist layer on a curved surface, an installation step of installing the curved material on a support member so that each curved surface of the plurality of curved materials is along one circle, and the photoresist layer Rotating at least one of the head that irradiates the laser beam and the support member around the central axis of the circle, and moving at least one of the head and the support member in the central axis direction from the head And an exposure step of irradiating with laser light.

  According to the present invention, for example, when the curved member has a curved surface such as a part of a cylinder such as a cylindrical lens, first, a plurality of curved materials (for example, a cylindrical material before forming a fine recess for antireflection) After the photoresist layer is formed on the curved surface of the lens, each curved surface material is placed on the support member so that the curved surface of each curved surface material follows one circle. Thereby, each part of one cylindrical surface is constituted by the curved surface of each curved surface material, and each curved surface is substantially flush in the circumferential direction. Then, for example, the support member is rotated around the center axis of the circle, and the head is irradiated with laser light while moving the head along the center axis. As a result, the laser beam is scanned in a spiral shape with the center axis of the circle as the center, and a pattern corresponding to the irradiation of the laser beam is formed on the photoresist layers of the plurality of curved surface materials. Therefore, the laser beam can be continuously scanned over a plurality of curved materials as compared with the conventional method of intermittently scanning the laser beam by repeatedly stopping and moving the XY table. The scanning time of the laser beam can be shortened. Further, when scanning a photoresist layer formed on a curved surface shaped like a part of a cylinder, it is not necessary to move the laser beam in the direction of the optical axis as described above. Compared with the method using the Y table, the scanning time of the laser beam can be shortened.

  In the method for processing a photoresist layer and the method for manufacturing a curved member according to the present invention, it is desirable that the photoresist layer is formed of a material capable of changing the shape in a heat mode.

  According to this, a hole smaller than the spot diameter of the laser beam is formed in the photoresist layer only by irradiating the photoresist layer with the laser beam. Therefore, a fine hole of submicron order is formed in the photoresist layer. It can be formed quickly.

  In the method for processing a photoresist layer and the method for producing a curved member according to the present invention, when the curved surface is formed non-parallel to the central axis, in the exposure step, the photoresist layer It is desirable to move the focal point of the laser beam in the radial direction of the circle so that the focal point position of the laser beam is within a certain range.

  According to this, for example, when the curved surface is a part of a spherical surface and the support member is rotated around the central axis of the circle and the head is moved in the central axis direction, the head is moved in the central axis direction. At this time, the focal point of the laser beam is moved in the radial direction of the circle so that the focal position of the laser beam with respect to the photoresist layer falls within a certain range. That is, for example, when moving the head in the direction of the central axis, the head is moved on each curved surface of a plurality of curved materials only by moving the head in an arc shape with a predetermined curvature radius so as to pass through the top of the spherical curved surface. The focal position of the laser beam is within a certain range with respect to the photoresist layer. Therefore, when the spherical surface is scanned by the conventional method using the XY table, when scanning the laser beam in the Y direction at each position in the X direction, the radius of curvature varies depending on each position. In addition, the movement of the laser beam had to be controlled at the same time, but this is not necessary in the present invention. Therefore, even when the curved surface is formed non-parallel to the central axis, the laser beam scanning time can be shortened as compared with the conventional method using an XY table.

  Further, in the method of manufacturing a curved member according to the present invention, after the exposure step, etching is performed using the photoresist layer remaining on the curved surface of the curved material as a mask, and then the photoresist layer is removed. You may further provide the uneven | corrugated formation process which forms the uneven | corrugated pattern by an etching on the curved surface of a curved-surface-shaped material.

  According to this, a favorable uneven | corrugated pattern can be formed in the curved surface of a curved-surface-shaped material by an etching.

  In the method for processing a photoresist layer and the method for manufacturing a curved member according to the present invention, the support member may be formed in a cylindrical shape, and the plurality of curved materials may be disposed on the inner surface of the support member. .

  According to this, when rotating the support member around the central axis, even if a centrifugal force directed outward is applied to each curved surface material, each curved surface material is pressed by the support member and is moved outward by the centrifugal force. It is prevented from being skipped. Furthermore, since each curved surface material is pressed toward the support member by the centrifugal force, each curved surface material and the support member can be firmly fixed.

  According to the present invention, laser light can be continuously scanned for a plurality of curved materials, so that the laser light can be scanned in a short time with respect to the photoresist layer of each curved material.

Next, an embodiment of the present invention will be described in detail with reference to the drawings as appropriate.
As shown in FIGS. 1A and 1B, a photoresist layer processing apparatus 1 is an apparatus for executing a photoresist layer processing method according to the present invention, and mainly includes a support member 2 and a head 3. The moving device 4 and the control device 5 are provided.

  The support member 2 is formed in a quadrangular prism shape, and a central shaft 2 </ b> A is integrally formed so as to penetrate a pair of opposing surfaces 21 and 21. Four surfaces other than the pair of surfaces 21 and 21 are formed at positions that are equidistant from the central axis 2A, thereby forming installation surfaces 22 for installing the workpiece 6. Here, the distance from the center axis 2A of each installation surface 22 is set to a distance corresponding to the radius of curvature of the surface 6a of each workpiece 6 so that the surfaces 6a of the workpieces 6 described later are arranged on one circle C. Has been. The support member 2 is appropriately controlled by the control device 5 so as to rotate at a predetermined rotational speed about the central axis 2A. The material of the support member 2 is preferably a metal in consideration of ease of processing and processing accuracy.

  As shown in FIG. 1A, the workpiece 6 includes a cylindrical lens 61 formed of a material such as a resin or glass as an example of a curved material, and an arc shape in cross section of the cylindrical lens 61 (part of a cylindrical surface). And a photoresist layer 62 formed in a uniform thin film thickness by a method such as spin coating. Here, the photoresist layer 62 according to the present embodiment is a layer in which light is converted into heat by intense light irradiation, and the shape of the material can be changed by this heat to form a hole. A layer of mode-type photoresist material. A specific example of the photoresist layer 62 will be described in detail later. A plurality (four) of the workpieces 6 are prepared, and are fixed to each installation surface 22 of the support member 2 with an adhesive or the like so that each surface 6a (curved surface 61a) thereof is along one circle C. It is like that. That is, each work 6 is fixed to each installation surface 22 of the support member 2 so that each surface 6 a of the plurality of works 6 is substantially flush with the rotation direction of the support member 2.

  The head 3 is a device that irradiates the photoresist layer 62 of each workpiece 6 fixed to the support member 2 with laser light. The head 3 is configured to be movable along the central axis 2 </ b> A of the support member 2 by the moving device 4.

  The moving device 4 supports the head 3 so as to be movable along the central axis 2 </ b> A of the support member 2. The moving device 4 moves the head 3 in synchronization with the rotation of the support member 2 by being appropriately controlled by the control device 5.

  The control device 5 performs control for moving the head 3 along the central axis 2A and control for rotating the support member 2, and also a laser light source in the head 3 (or a shutter disposed on the optical axis of the laser light). Is controlled to intermittently irradiate the laser beam emitted from the head 3 based on predetermined data.

Next, a method for processing a photoresist layer according to the present invention will be described.
First, a plurality of cylindrical lenses 61 having a curved surface 61a having an arc shape in cross section are manufactured by a known method such as injection molding (preparation step). 2A, a plurality of workpieces 6 are manufactured by forming a photoresist layer 62 on the curved surface 61a of each cylindrical lens 61 by a method such as spin coating (resist forming step). And the some workpiece | work 6 is fixed to each installation surface 22 of the supporting member 2 so that each surface 6a (curved surface 61a) follows one circle C, as shown to Fig.1 (a) (installation process). .

  After the support member 2 is rotated and the rotation is stabilized, the head 3 is moved along the central axis 2A of the support member 2 and the laser beam is appropriately turned ON / OFF from the head 3 based on predetermined data. (Exposure process). As a result, the laser beam scans around the support member 2 in a spiral manner with the gap (gap) between the head 3 and the workpiece 6 kept constant, so that a plurality of holes are formed in each workpiece 6 in a predetermined manner. It is formed accurately and quickly with a pitch.

  Then, the manufacturing method of the cylindrical lens 61 concerning this invention is demonstrated. In addition, the processing method of the photoresist layer mentioned above is a part of process of the manufacturing method of the cylindrical lens 61 demonstrated below.

  As described above, after irradiating the entire outer peripheral surface of the support member 2 with the laser beam in a spiral manner, when each workpiece 6 is removed from the support member 2, as shown in FIG. A plurality of holes 62 a are formed in the resist layer 62. Then, after a plurality of holes 62a are formed in the photoresist layer 62, etching is performed using the photoresist layer 62 remaining on the curved surface 61a of the cylindrical lens 61 as a mask, as shown in FIG. 2C. A concave portion 61 b is formed on the curved surface 61 a of the lens 61. Here, various etching methods such as wet etching, dry etching, and RIE (reactive ion etching) can be employed as the etching.

  And after forming the recessed part 61b, the uneven | corrugated pattern (recessed part 61b) by etching is formed in the curved surface 61a of the cylindrical lens 61 by removing the photoresist layer 62 with washing | cleaning liquids, such as ethanol (unevenness formation process). Thus, a cylindrical lens 61 (curved surface member) having a reflection suppressing function in which a plurality of minute concave portions 61b are formed on the curved surface 61a is manufactured.

According to the above, the following effects can be obtained in the present embodiment.
Since the laser beam is scanned in a spiral shape around the central axis 2 </ b> A of the support member 2, a plurality of holes 62 a can be quickly formed in the photoresist layers 62 of the plurality of workpieces 6. That is, since the laser beam can be continuously scanned by repeatedly stopping and moving the XY table, the processing time can be shortened.

  Since the photoresist layer 62 is formed of a material capable of changing the shape in the heat mode, the hole 62a smaller than the spot diameter of the laser beam is formed only by irradiating the photoresist layer 62 with the laser beam. Formed. Therefore, fine holes 62a on the order of submicrons can be quickly formed in the photoresist layer 62.

In addition, this invention is not limited to the said embodiment, It can utilize with various forms so that it may illustrate below.
In the said embodiment, although the installation process was performed after the resist formation process, this invention is not limited to this, You may perform an installation process before a resist formation process. Specifically, for example, after the plurality of cylindrical lenses 61 before the formation of the photoresist layer 62 in the above-described embodiment are installed on the support member 2 along the circle C, a photo is applied to each curved surface 61a of each cylindrical lens 61. A resist layer 62 may be formed. Here, as a method of forming the photoresist layer 62, for example, the support member 2 supporting the plurality of cylindrical lenses 61 is immersed in a coating solution obtained by dissolving a photoresist material in an organic solution, and then lifted up. A method of forming the photoresist layer 62 on each curved surface 61a by drying the coating solution applied to the curved surface 61a of the cylindrical lens 61 can be employed. In this case, the film thickness of the photoresist layer 62 applied to each curved surface 61a of the plurality of cylindrical lenses 61 can be made substantially uniform by pulling up the coating member while rotating the support member 2 about the central axis 2A. it can. Furthermore, when the cylindrical lens 61 is made of glass, the curved surface 61a of each cylindrical lens 61 is placed by a lathe or a polishing machine after the plurality of cylindrical lenses 61 are installed on the support member 2 and before the photoresist layer 62 is formed. Can be finished together. That is, the curved surfaces 61a of the plurality of cylindrical lenses 61 can be finished while the support member 2 supports the plurality of cylindrical lenses 61 and rotates the support member 2 about the central axis 2A. Furthermore, after finishing as described above, the curved surfaces 61a of the plurality of cylindrical lenses 61 can be surely arranged along the same circle C.

In the said embodiment, although the supporting member 2 was made into the square pillar, this invention is not limited to this, For example, you may form in polygonal prism shapes other than square pillars, such as a triangular prism and a pentagonal prism, and the outer peripheral surface of a cylinder It may be formed in a shape provided with a plurality of flat installation surfaces.
In the above embodiment, only one cylindrical lens 61 is provided in the direction of the central axis 2A. However, the present invention is not limited to this, and a plurality of cylindrical lenses 61 may be provided in the direction of the central axis 2A.

  In the above-described embodiment, the cylindrical lens 61 having a convex curved surface 61a on one side is employed as the curved material, but the present invention is not limited to this. For example, a lens whose both surfaces are convex, a concave lens having a concave curved surface, an LED (light emitting diode) cover (surface through which light is transmitted), a mold for molding a lens, an original mold, etc. are employed. be able to. In the case of a lens having convex surfaces, the lens installation surface may be formed in a spherical shape following the lens surface. Further, for example, as a mold original plate, for example, a workpiece 6 before etching as shown in FIG. That is, by performing plating on the workpiece 6 shown in FIG. 2B, a metal mold to which the uneven pattern of the workpiece 6 is transferred can be manufactured.

  Further, when processing a curved material having a curved surface that is not parallel to the central axis 2A, instead of the cylindrical lens 61 having the curved surface 61a parallel to the central axis 2A as in the above-described embodiment, the laser beam is used as the central axis. When moving in the direction 2A, it is desirable to reciprocate the focal point of the laser beam in a direction approaching and away from the curved surface.

  For example, as shown in FIG. 3A, in a spherical lens 71 having a curved surface 71a having a shape like a part of a spherical surface, the curved surface 71a is formed on the support member 2 as shown in FIG. It is not parallel to the central axis 2A. In this case, if the head 3 is simply moved along the central axis 2A as in the above-described embodiment, a large error occurs in the gap between the head 3 and the photoresist layer 72 formed on the curved surface 71a. Therefore, as shown in FIG. 3B, when the head 3 is moved in the direction of the central axis 2A, the head 3 is moved to the curved surface 71a (specifically, the surface of the photoresist layer 72; the surface 7a of the workpiece 7). By moving in a circular arc shape passing through the apex, the focal point of the laser light is moved in the radial direction of the circle C shown in FIG. Thereby, the focal position of the laser beam with respect to the photoresist layer 72 can be kept within a certain range.

  More specifically, as shown in FIG. 3A, when the curved surfaces 71a are arranged so as to coincide with one circle C (when arranged so that the centers of the curved surfaces 71a coincide), the spherical curved surfaces 71a are arranged. (The surface 7a of the work 7) constitutes a part of one spherical surface. Therefore, the cross-sectional views along the XX line, the YY line, and the ZZ line orthogonal to the central axis 2A shown in FIG. 3B are as shown in FIGS. 4A to 4C. It becomes. That is, since each curved surface 71a is formed at an equal distance from the central axis 2A in any cross section, the work 3 is moved in an arc shape and the support member 2 is rotated as shown in FIG. 7, the entire surface 7 a of the work 7 can be scanned with laser light while keeping the gap between the surface 7 a of the head 7 and the head 3 substantially the same.

  In the form shown in FIG. 3, the head 3 is arranged so that the optical axis of the laser beam is orthogonal to the central axis 2A in FIG. 3B, for example, without moving the head 3 in an arc shape. May be moved along the surface 7a of the workpiece 7 by moving in the optical axis direction without changing the direction while moving in parallel to the direction of the central axis 2A. Further, the focal position may be changed by moving an optical component (laser light source, objective lens, etc.) in the head 3. The curved surface that is not parallel to the central axis 2A is not limited to the curved surface 71a such as a part of a spherical surface as shown in FIG. 3, but may be an aspherical surface.

  In the above embodiment, the support member 2 is rotated and the head 3 is moved in the axial direction. However, the present invention is not limited to this, and for example, the head 3 may be rotated and the support member 2 may be moved in the axial direction. .

  In the embodiment, the plurality of workpieces 6 having convex curved surfaces are installed on the outer peripheral surface of the support member 2, but the present invention is not limited to this, and the support formed in a cylindrical shape as shown in FIG. You may install the some workpiece | work 8 which has a concave curved surface in each internal peripheral surface 201 of the member 200. FIG. In addition, as the workpiece | work 8, what is comprised by the concave lens 81 which has the curved surface 81a which becomes a shape like a part of cylinder, and the photoresist layer 82 formed on the curved surface 81a is employable. According to this, the laser beam is spirally applied to the plurality of workpieces 8 by moving the head 3 along the central axis 210 while rotating the support member 200 around the central axis 210 in the same manner as in the above embodiment. Can be scanned to reduce the scanning time. Further, in this embodiment, even if a centrifugal force directed outward is applied to each workpiece 8, each workpiece 8 is suppressed by the support member 200 and is prevented from being blown outward by the centrifugal force. Furthermore, since each workpiece 8 is pressed toward the support member 200 by centrifugal force, each workpiece 8 and the support member 200 can be firmly fixed. In the embodiment shown in FIG. 5, the concave lens 81 is used as the curved material. However, the present invention is not limited to this, and may be a concave mold for forming a convex lens, for example.

  In the embodiment, the plurality of holes 62a are formed in the photoresist layer 62. However, the present invention is not limited to this, and for example, line patterns formed in parallel to each other may be formed. In addition, the processing of the photoresist layer includes a form in which a hole is actually formed as in the above embodiment, and the photoresist layer is formed of a material that changes into a physical property that can be dissolved by a developer upon exposure. In this case, even if no hole is formed in the photoresist layer, a case where a predetermined pattern is formed in a portion whose physical properties have been changed by exposure is also included.

  The material of the photoresist layer 62 is not limited to the heat mode type material as in the above-described embodiment. For example, a photon mode type material or a material that changes to a physical property that can be dissolved (or cannot be dissolved) by a developer upon exposure. (Positive type, negative type) or the like can be employed. Here, in the case where the positive or negative photoresist layer described above is employed, a step of removing the photoresist layer with a developer may be provided between the exposure step and the unevenness forming step. Specific examples of the heat mode type photoresist material, processing conditions for the photoresist layer, and the like are as shown below.

  Heat mode type photoresist material is a recording material that has been widely used in recording layers such as optical recording disks, for example, cyanine-based, phthalocyanine-based, quinone-based, squarylium-based, azurenium-based, thiol complex-based, merocyanine-based, etc. The recording material can be used.

The photoresist layer in the present invention is preferably a pigment type containing a pigment as a photoresist material.
Accordingly, examples of the photoresist material contained in the photoresist layer include organic compounds such as pigments. Note that the photoresist material is not limited to an organic material, and an inorganic material or a composite material of an inorganic material and an organic material can be used. However, in the case of an organic material, it is preferable to employ an organic material because film formation can be easily performed by spin coating or spray coating, and a material having a low transition temperature can be easily obtained. Among organic materials, it is preferable to employ a dye whose light absorption can be controlled by molecular design.

  Preferred examples of the photoresist layer include methine dyes (cyanine dyes, hemicyanine dyes, styryl dyes, oxonol dyes, merocyanine dyes), macrocyclic dyes (phthalocyanine dyes, naphthalocyanine dyes, porphyrin dyes, etc.), azo dyes, and the like. Examples thereof include dyes (including azo metal chelate dyes), arylidene dyes, complex dyes, coumarin dyes, azole derivatives, triazine derivatives, 1-aminobutadiene derivatives, cinnamic acid derivatives, and quinophthalone dyes. Of these, methine dyes, oxonol dyes, macrocyclic dyes, and azo dyes are preferable.

  Such a dye-type photoresist layer preferably contains a dye having absorption in the exposure wavelength region. In particular, the upper limit of the extinction coefficient k indicating the amount of light absorption is preferably 10 or less, more preferably 5 or less, further preferably 3 or less, and 1 or less. Most preferred. The reason is that if the extinction coefficient k is too high, light does not reach from the light incident side to the opposite side of the photoresist layer, and uneven holes are formed. Further, the lower limit value of the extinction coefficient k is preferably 0.0001 or more, more preferably 0.001 or more, and further preferably 0.1 or more. The reason is that if the extinction coefficient k is too low, the amount of light absorption is reduced, so that a larger laser power is required and the processing speed is reduced.

Note that the photoresist layer needs to absorb light at the exposure wavelength as described above, and from such a viewpoint, a dye can be appropriately selected or the structure can be modified according to the wavelength of the laser light source. .
For example, when the oscillation wavelength of the laser light source is around 780 nm, it is advantageous to select from pentamethine cyanine dye, heptamethine oxonol dye, pentamethine oxonol dye, phthalocyanine dye, naphthalocyanine dye, and the like. Among these, it is preferable to use a phthalocyanine dye or a pentamethine cyanine dye.
When the oscillation wavelength of the laser light source is around 660 nm, it is advantageous to select from a trimethine cyanine dye, a pentamethine oxonol dye, an azo dye, an azo metal complex dye, a pyromethene complex dye, and the like.
Further, when the oscillation wavelength of the laser light source is around 405 nm, a monomethine cyanine dye, monomethine oxonol dye, zero methine merocyanine dye, phthalocyanine dye, azo dye, azo metal complex dye, porphyrin dye, arylidene dye, complex It is advantageous to select from dyes, coumarin dyes, azole derivatives, triazine derivatives, benzotriazole derivatives, 1-aminobutadiene derivatives, quinophthalone dyes, and the like.

Examples of preferable compounds for the photoresist layer (photoresist material) are shown below when the oscillation wavelength of the laser light source is around 780 nm, around 660 nm, and around 405 nm. Here, the compounds (I-1 to I-10) represented by the following chemical formulas 1 and 2 are compounds when the oscillation wavelength of the laser light source is around 780 nm. Further, the compounds (II-1 to II-8) represented by the chemical formulas 3 and 4 are compounds in the case of around 660 nm. Furthermore, the compounds (III-1 to III-14) represented by the chemical formulas 5 and 6 are compounds in the case of around 405 nm. In addition, this invention is not limited to the case where these are used for a photoresist material.

<Example of photoresist material when the oscillation wavelength of the laser light source is around 780 nm>

<Example of photoresist material when the oscillation wavelength of the laser light source is around 780 nm>

<Example of photoresist material when the oscillation wavelength of the laser light source is around 660 nm>

<Example of photoresist material when the oscillation wavelength of the laser light source is around 660 nm>

<Example of photoresist material when the oscillation wavelength of the laser light source is around 405 nm>

<Example of photoresist material when the oscillation wavelength of the laser light source is around 405 nm>

  JP-A-4-74690, JP-A-8-127174, 11-53758, 11-334204, 11-334205, 11-334206, 11-334207 The dyes described in JP-A No. 2000-43423, JP-A No. 2000-108513, JP-A No. 2000-158818, and the like are also preferably used.

Such a dye-type photoresist layer is prepared by dissolving a dye in a suitable solvent together with a binder or the like to prepare a coating solution, and then coating the coating solution on a substrate to form a coating film. It can be formed by drying. In that case, it is preferable that the temperature of the surface which apply | coats a coating liquid is the range of 10-40 degreeC. More preferably, the lower limit is 15 ° C. or higher, more preferably 20 ° C. or higher, and particularly preferably 23 ° C. or higher. Moreover, as an upper limit, it is more preferable that it is 35 degrees C or less, It is still more preferable that it is 30 degrees C or less, It is especially preferable that it is 27 degrees C or less. As described above, when the surface temperature to be applied is in the above range, it is possible to prevent the occurrence of coating unevenness and coating failure and make the thickness of the coating film uniform.
Each of the upper limit value and the lower limit value can be arbitrarily combined.
Here, the photoresist layer may be a single layer or a multilayer. In the case of a multilayer structure, the photoresist layer is formed by performing the coating process a plurality of times.
The concentration of the dye in the coating solution is generally in the range of 0.01 to 15% by mass, preferably in the range of 0.1 to 10% by mass, more preferably in the range of 0.5 to 5% by mass, most preferably. It is the range of 0.5-3 mass%.

Examples of the solvent for the coating solution include esters such as butyl acetate, ethyl lactate and cellosolve acetate; ketones such as methyl ethyl ketone, cyclohexanone and methyl isobutyl ketone; chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane and chloroform; dimethylformamide and the like Amides; Hydrocarbons such as methylcyclohexane; Ethers such as tetrahydrofuran, ethyl ether, dioxane; Alcohols such as ethanol, n-propanol, isopropanol, n-butanol diacetone alcohol; 2,2,3,3-tetrafluoropropanol, etc. Fluorinated solvents; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether; That. Fluorine solvents, glycol ethers, and ketones are preferred. Particularly preferred are fluorine type solvents and glycol ethers. More preferred are 2,2,3,3-tetrafluoropropanol and propylene glycol monomethyl ether.
The said solvent can be used individually or in combination of 2 or more types in consideration of the solubility of the pigment | dye to be used. In the coating solution, various additives such as an antioxidant, a UV absorber, a plasticizer, and a lubricant may be added according to the purpose.

Examples of the coating method include a spray method, a spin coating method, a dip method, a roll coating method, a blade coating method, a doctor roll method, a doctor blade method, and a screen printing method. In addition, it is preferable to employ the spin coating method in terms of excellent productivity and easy control of the film thickness.
The photoresist layer is preferably dissolved at 0.3 wt% or more and 30 wt% or less, more preferably 1 wt% or more and 20 wt% or less with respect to the organic solvent from the viewpoint that it is advantageous for formation by a spin coating method. preferable. In particular, it is preferable to dissolve in tetrafluoropropanol at 1 wt% or more and 20 wt% or less. Further, the photoresist material preferably has a thermal decomposition temperature of 150 ° C. or higher and 500 ° C. or lower, and more preferably 200 ° C. or higher and 400 ° C. or lower.
At the time of application, the temperature of the coating solution is preferably in the range of 23 to 50 ° C, more preferably in the range of 24 to 40 ° C, and particularly preferably in the range of 25 to 30 ° C.

  When the coating solution contains a binder, examples of the binder include natural organic polymer materials such as gelatin, cellulose derivatives, dextran, rosin, and rubber; hydrocarbon resins such as polyethylene, polypropylene, polystyrene, and polyisobutylene; Vinyl resins such as polyvinyl chloride, polyvinylidene chloride, polyvinyl chloride / polyvinyl acetate copolymer, acrylic resins such as polymethyl acrylate and polymethyl methacrylate, polyvinyl alcohol, chlorinated polyethylene, epoxy resin, butyral resin And synthetic organic polymers such as initial condensation products of thermosetting resins such as rubber derivatives and phenol / formaldehyde resins. When a binder is used in combination as a material for the photoresist layer, the amount of the binder used is generally in the range of 0.01 to 50 times (mass ratio) with respect to the dye, preferably 0.1 times. The amount is in the range of 5 to 5 times (mass ratio).

The photoresist layer can contain various anti-fading agents in order to improve the light resistance of the photoresist layer.
As the antifading agent, a singlet oxygen quencher is generally used. As the singlet oxygen quencher, those described in publications such as known patent specifications can be used.
Specific examples thereof include JP-A Nos. 58-175893, 59-81194, 60-18387, 60-19586, 60-19587, and 60-35054. 60-36190, 60-36191, 60-44554, 60-44555, 60-44389, 60-44390, 60-54892, JP-A-60-47069, 63-29995, JP-A-4-25492, JP-B-1-38680, JP-A-6-26028, etc., German Patent 350399, and Japan Examples include those described in Chemical Society Journal, October 1992, page 1141. The use amount of the antifading agent such as the singlet oxygen quencher is usually in the range of 0.1 to 50% by weight, preferably in the range of 0.5 to 45% by weight, based on the amount of the dye. Preferably, it is the range of 3-40 mass%, Most preferably, it is the range of 5-25 mass%.

  Note that the photoresist layer can be formed by a film forming method such as vapor deposition, sputtering, or CVD in accordance with the physical properties of the material.

In addition, the pigment | dye has a light absorption rate higher than the other wavelength in the wavelength of the laser beam used for the process of a hole part pattern.
The wavelength of the absorption peak of the dye is not necessarily limited to that in the visible light wavelength range, and may be in the ultraviolet range or the infrared range.

  The wavelength λw of the laser light for forming the hole pattern may be a wavelength that can provide a large laser power. For example, when a dye is used for the photoresist layer, 193 nm, 210 nm, 266 nm, 365 nm, 405 nm It is preferably 1000 nm or less, such as 488 nm, 532 nm, 633 nm, 650 nm, 680 nm, 780 nm, 830 nm.

  Further, the laser light may be continuous light or pulsed light, but it is preferable to employ laser light whose emission interval can be freely changed. For example, it is preferable to employ a semiconductor laser. When the laser cannot be directly on / off modulated, it is preferable to modulate with an external modulation element.

  Further, the laser power is preferably higher in order to increase the processing speed. However, as the laser power is increased, the scanning speed (speed for scanning the photoresist layer with laser light; for example, the rotational speed of the support member 2 according to the embodiment) must be increased. Therefore, the upper limit value of the laser power is preferably 100 W in consideration of the upper limit value of the scanning speed, more preferably 10 W, still more preferably 5 W, and most preferably 1 W. The lower limit of the laser power is preferably 0.1 mW, more preferably 0.5 mW, and even more preferably 1 mW.

  Further, the laser light is preferably light that has excellent transmission wavelength width and coherency and can be narrowed down to a spot size that is comparable to the wavelength. As the exposure strategy (light pulse irradiation conditions for properly forming the hole pattern), it is preferable to adopt a strategy used in an optical disc. That is, it is preferable to adopt conditions such as the exposure speed, the peak value of the laser beam to be irradiated, and the pulse width as used in optical disks.

The thickness of the photoresist layer should correspond to the type of etching gas used for etching and the depth of the hole formed in the photoresist layer.
This thickness can be appropriately set, for example, in the range of 1 to 10000 nm, and the lower limit of the thickness is preferably 10 nm or more, and more preferably 30 nm or more. The reason is that if the thickness is too thin, it is difficult to obtain an effect as an etching mask. Moreover, the upper limit of thickness becomes like this. Preferably it is 1000 nm or less, More preferably, it is 500 nm or less. The reason is that if the thickness is too thick, a large laser power is required, and it becomes difficult to form a deep hole, and further, the processing speed decreases.

  The photoresist layer t and the hole diameter d are preferably in the following relationship. That is, the upper limit value of the thickness t of the photoresist layer is preferably a value satisfying t <10d, more preferably a value satisfying t <5d, and further a value satisfying t <3d. preferable. The lower limit value of the thickness t of the photoresist layer is preferably a value satisfying t> d / 100, more preferably a value satisfying t> d / 10, and satisfying t> d / 5. More preferably, it is a value. The reason why the upper limit value and the lower limit value of the thickness t of the photoresist layer are set in this manner in relation to the diameter d of the hole is the same as described above.

Next, an example in which the effect of the present invention has been confirmed will be described.
[Work preparation]
As a curved material, a glass convex lens having a diameter of 20 mm was prepared, and a photoresist material was applied to the curved surface by spin coating to form a photoresist layer having a thickness of 100 nm after drying. Specifically, the photoresist layer was formed by dissolving 2 g of a dye material having the following chemical formula in 100 ml of a TFP (tetrafluoropropanol) solvent and applying the solution onto the curved surface of the convex lens by spin coating. Thereby, a work composed of a convex lens and a photoresist layer was produced.

[Installation process]
A cubic support member having a side of 25 mm was prepared, and four convex lenses were arranged and fixed at the centers of the four side surfaces.

[Exposure process]
A plurality of fine recesses (dots) were recorded with NE0500 (wavelength 405 nm, NA 0.85) manufactured by Pulstec Industrial Co., Ltd. The conditions at this time are as follows.
Arrangement pitch of each recess: 0.3 μm
Laser power: 2mW
Linear velocity: 5m / s
Recording signal: 5 MHz rectangular wave It should be noted that, in order to satisfy such a condition, the concave portion was formed in a spiral shape by naturally moving the support member little by little while rotating the support member. Specifically, a plurality of concave portions having a pitch of 300 nm and a diameter of 200 nm were formed in the spiral direction.

  As a result, it was confirmed that the scanning of the laser beam on each surface of the four workpieces was completed in a short time such as about 20 minutes. In addition, after forming the recessed part in each workpiece | work, the workpiece | work was removed from the support member and the curved surface of the convex lens was etched by RIE. Thereafter, it was confirmed that a fine dot pattern with a pitch of 300 nm was formed on the curved surface of the convex lens by washing away the photoresist layer.

It is the front view (a) which shows the photoresist layer processing apparatus for performing the processing method of the photoresist layer based on this invention, and a side view (b). Cross-sectional view (a) showing the resist forming step, cross-sectional view (b) showing the exposure step, cross-sectional view (c) showing the state of etching in the concave-convex forming step, and photoresist layer in the concave-convex forming step It is sectional drawing (d) which shows the state removed. They are the front view (a) which shows the photoresist layer processing apparatus for processing the photoresist layer formed in the curved surface of a spherical lens, and a side view (b). They are XX sectional drawing (a) of FIG.3 (b), YY sectional drawing (b) of FIG.3 (b), and ZZ sectional drawing (c) of FIG.3 (b). It is a front view which shows the photoresist layer processing apparatus for processing the photoresist layer formed in the curved surface of a concave lens.

Explanation of symbols

2 Support member 2A Central axis 3 Head 4 Moving device 5 Control device 6 Work 6a Surface 61 Cylindrical lens 61a Curved surface 61b Recessed portion 62 Photoresist layer 62a Hole

Claims (9)

A preparation step of preparing a plurality of curved-surface-shaped materials having a circular arc-shaped curved surface in section;
A resist forming step of forming a photoresist layer on the curved surface of the curved material;
An installation step of installing the curved surface material on a support member so that each curved surface of the plurality of curved surface materials is along one circle;
While rotating at least one of the head for irradiating the photoresist layer with laser light and the support member around the center axis of the circle, moving at least one of the head and the support member in the direction of the center axis And an exposure step of irradiating a laser beam from the head.   The method for processing a photoresist layer according to claim 1, wherein the photoresist layer is formed of a material capable of changing a shape in a heat mode. The curved surface is formed non-parallel to the central axis;
In the exposure step,
3. The photoresist layer according to claim 1, wherein the focal point of the laser beam is moved in a radial direction of the circle so that a focal position of the laser beam with respect to the photoresist layer falls within a certain range. Processing method.   4. The photoresist layer according to claim 1, wherein the support member is formed in a cylindrical shape, and the plurality of curved materials are disposed on an inner surface of the support member. 5. Processing method. A preparation step of preparing a plurality of curved-surface-shaped materials having a circular arc-shaped curved surface in section;
A resist forming step of forming a photoresist layer on the curved surface of the curved material;
An installation step of installing the curved surface material on a support member so that each curved surface of the plurality of curved surface materials is along one circle;
While rotating at least one of the head for irradiating the photoresist layer with laser light and the support member around the center axis of the circle, moving at least one of the head and the support member in the direction of the center axis And an exposure step of irradiating a laser beam from the head.   6. The method of manufacturing a curved member according to claim 5, wherein the photoresist layer is formed of a material capable of changing a heat mode shape. The curved surface is formed non-parallel to the central axis;
In the exposure step,
The curved member according to claim 5 or 6, wherein the focal point of the laser beam is moved in the radial direction of the circle so that the focal position of the laser beam with respect to the photoresist layer falls within a certain range. Production method.   After the exposure step, etching is performed using the photoresist layer remaining on the curved surface of the curved material as a mask, and then the photoresist layer is removed, thereby forming an uneven pattern by etching on the curved surface of the curved material. The method for producing a curved member according to any one of claims 5 to 7, further comprising a forming step.   The curved member according to any one of claims 5 to 8, wherein the support member is formed in a cylindrical shape, and the plurality of curved materials are disposed on an inner surface of the support member. Production method.

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