WO2006109355A1

WO2006109355A1 - Multiple-beam microstructure laser lithographic method and device employing laser beams of different wavelength

Info

Publication number: WO2006109355A1
Application number: PCT/JP2005/007012
Authority: WO
Inventors: Hiroshi Masuhara; Shoji Ito
Original assignee: Japan Science And Technology Agency; D-Mec Ltd.
Priority date: 2005-04-11
Filing date: 2005-04-11
Publication date: 2006-10-19

Abstract

A multiple-beam microstructure laser lithographic method and device employing laser beams of different wavelengths in which three-dimensional space selectivity of nano level can be imparted by employing, in addition to a laser beam for inducing a curing reaction, a laser beam for accelerating the reaction having a wavelength different from that of the laser beam for inducing the curing reaction. A photo-curing reaction can be induced only at and near a focused spot by irradiating the spot with a laser beam (5) for accelerating the reaction in a state where resin is irradiated with a laser beam (4) for inducing the curing reaction with such an extremely weak intensity as to not induce the photo-curing reaction.

Description

Multi-beam microstructure optical modeling method and apparatus using different wavelength laser beam

The present invention relates to a multi-beam microstructure optical modeling method and apparatus using different wavelength laser light.

Background art

In recent years, a condensing spot of a laser beam is scanned in a photocurable resin, the resin is cured to a desired shape, and a complicated three-dimensional structure is obtained in a shorter time than conventional semiconductor processes. The stereolithography method that can form the surface has been put into practical use and is used in fields such as rapid prototyping.

[0003] The processing accuracy of currently available stereolithography machines is about 50-: LOO m, and the development of micro stereolithography technology is progressing with the aim of producing finer three-dimensional structures.

[0004] In the optical modeling technique, the size of the cured portion of the photocurable resin is determined by the focused spot diameter of the laser beam.

[0005] Therefore, a fine structure can be manufactured by focusing light on a smaller area with an objective lens having a high light collecting ability (that is, a large NA) (see Non-Patent Documents 1 and 2 below). However, in reality, even if the light is focused by the objective lens, the photocuring does not occur only at the converging spot, but the curing reaction also occurs around the converging spot.

[0006] Therefore, there has been reported a method for improving modeling accuracy using two-photon polymerization induced by femtosecond laser pulse irradiation for finer optical modeling (see Non-Patent Documents 3 and 4 below).

[0007] The conventional micro stereolithography technique described above is disclosed in Patent Document 14 below.

Patent Document 1: Japanese Patent Laid-Open No. 2003-025295

Patent Document 2: JP 2001-158050 A

Patent Document 3: Japanese Patent Laid-Open No. 7-329188 Patent Document 4: Japanese Patent Laid-Open No. 2003-001599

Non-Patent Literature l: Makoto Horiyama, Hong— Bo Sun, Masafumi Miwa, Shige Ki Kimatsuo, and Hiroaki Misawa, Japanese Journal of Applied Physi cs 38, pp. L212 -L215 (1999).

Non-Patent Document 2: Shoji Maruo and Koji Ikuta, Applied Physics Letters 7 6, p. 2656 (2000).

Non-Patent Document 3: Shoji Maruo, Osamu Nakamura, and Satoshi Kawata, Optics Letters 22, p. 132 (1997).

Non-Patent Document 4: Hong— Bo Sun, Takeshi Kawakami, Ying Xu, Jia-Yu Ye, Shigeki Matsuo, Hiroaki Misawa, Masafumi Miwa, and Reizo Kane ko, Optics Letters 25, p. 1110 (2000).

Disclosure of the invention

[0008] As described above, the reason why it is difficult to improve the modeling accuracy in the one-photon process is that light absorption occurs in a region other than the focused spot of the laser beam, that is, a region outside the scanning locus of the focused spot. This is because a curing reaction occurs. In general, the photocuring reaction is a threshold reaction, and curing occurs when the amount of light irradiation exceeds a certain threshold. Two-photon polymerization can have high spatial selectivity because the two-photon absorption probability is proportional to the square of the light intensity, and therefore light absorption occurs only near the condensing spot.

Therefore, in order to impart spatial selectivity to photopolymerization, it is only necessary to increase the photopolymerization efficiency at the condensing spot of the curing laser light as compared to the surroundings.

[0010] In addition to a curing reaction inducing laser beam (in the embodiment, an ultraviolet laser beam), the present invention provides a reaction promoting laser beam having a wavelength different from that of the curing reaction inducing laser beam (in the example, a near infrared laser). By using (light), nano-level three-dimensional spatial selectivity can be achieved.

That is, in view of the above situation, the present invention is in addition to the laser beam for inducing the curing reaction.

Multi-beam microstructures using different wavelength laser light that can give nano-level three-dimensional spatial selectivity by using a reaction promoting laser light having a wavelength different from that of the curing reaction inducing laser light An object is to provide an optical modeling method and apparatus. In order to achieve the above object, the present invention provides

[1] In a multi-beam microstructure optical modeling method using laser beams of different wavelengths, a curing reaction-inducing laser beam is irradiated into a photocurable resin, and a laser beam for promoting a reaction at a different wavelength is cured. By irradiating the photocurable resin in superposition with the laser beam for inducing reaction, a photocuring reaction is induced only in the vicinity of the focused spot where the two laser beams overlap.

[2] In the multi-beam microstructure optical modeling method using the different wavelength laser beam described in [1] above, the curing reaction-inducing laser beam is absorbed in the photocurable resin. It is characterized by being one laser beam and having an extremely weak light intensity, and the one reaction promoting laser beam is a laser beam having another wavelength that is not absorbed by the photocurable resin.

[0014] [3] The multi-beam microstructure optical modeling method using the different wavelength laser beam described in [1] or [2] is characterized by having nano-level three-dimensional spatial selectivity. And

[4] In the multi-beam microstructure optical modeling method using the different wavelength laser beam described in [3] above, the intensity of the curing reaction-inducing laser beam is approximately 0.038-0. It is.

[5] In the multi-beam microstructure optical modeling method using the different wavelength laser beam described in [3] above, the wavelength of the reaction promoting laser beam is approximately 1064 nm.

[0017] [6] In the multi-beam microstructure optical modeling method using the different wavelength laser beam according to any one of [1] to [5], the photocurable mold dripped onto the glass substrate. The fat is irradiated with the curing reaction inducing laser light and the reaction promoting laser light from the glass substrate side.

[7] In the multi-beam microstructure optical modeling apparatus using a different wavelength laser beam, means for irradiating a curing reaction inducing laser beam having an extremely weak light intensity that does not induce a photocuring reaction, and the curing A means for irradiating a reaction promoting laser beam to the same spot as the curing reaction inducing laser light in a state where the reaction inducing laser light is irradiated in the photocurable resin, and a collection of the curing reaction inducing laser light. It is characterized by comprising a photocurable resin that induces a photocuring reaction only in the vicinity of the light spot.

[8] In the multi-beam microstructure optical modeling apparatus using the different wavelength laser beam described in [7] above The curing reaction-inducing laser beam has an intensity of about 0.038-0.076 / z W.

[9] In the multi-beam microstructure optical modeling apparatus using the different wavelength laser beam described in [7], the reaction promoting laser beam has a wavelength of approximately 1064 nm. .

[10] In the multi-beam microstructure optical modeling apparatus using the different wavelength laser beam described in [7] above, the photocurable resin in which the photocurable resin is dropped on a glass substrate The curing reaction inducing laser light and the reaction promoting laser light are irradiated from the glass substrate side.

[0022] [11] In the multi-beam micro structure stereolithography apparatus using the different wavelength laser beam according to any one of [7] to [10], the photocurable resin is It is an acrylic photocurable resin.

Brief Description of Drawings

FIG. 1 is a block diagram of a main part of a multi-beam micro structure object stereolithography apparatus using a two-beam micro-stereolithography method showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a resin line pattern formed by the two-beam micro-stereolithography method according to the first embodiment of the present invention.

FIG. 3 is a system configuration diagram of a multi-beam micro structure object stereolithography apparatus using a two-beam micro-stereolithography method showing a second embodiment of the present invention.

FIG. 4 is a view showing a scanning electron microscope image of a photocurable resin that has been spot-cured on a glass substrate according to a second embodiment of the present invention.

FIG. 5 is a diagram showing a columnar microstructure manufactured according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0024] According to the present invention, the photocuring reaction is not induced !, extremely weak !, for accelerating the reaction to the same spot in a state where the curing reaction-inducing laser light is irradiated into the resin at the light intensity. When a single laser beam is irradiated, a photo-curing reaction can occur only in the vicinity of the condensing spot of the curing reaction-inducing laser beam, and nano-level three-dimensional spatial selectivity can be achieved.

Hereinafter, embodiments of the present invention will be described in detail. Example 1

[0026] FIG. 1 is a configuration diagram of the main part of a multi-beam micro-structure stereolithography apparatus using a two-beam micro-stereolithography according to the first embodiment of the present invention, and FIG. It is a figure which shows the line pattern of the made resin.

[0027] In FIG. 1, 1 is a glass substrate, 2 is a stage, 3 is an objective lens (40 ×, NA: 0.9), 4 is an ultraviolet laser beam for inducing curing reaction (dotted line), and 5 is a near reaction promoting accelerator. Infrared laser light (solid line), 6 is a photocurable resin.

[0028] Therefore, the curing reaction-inducing ultraviolet laser beam 4 is condensed by the objective lens 3 at the interface between the glass substrate 1 and the photocurable resin 6, and the stage 2 is scanned, while the curing reaction-inducing ultraviolet laser beam is scanned. Turn on and off the near-infrared laser beam 5 for reaction promotion that is focused at the same point as The Ikko 4 Here, the photocurable resin 6 is, for example, an acrylic photocurable resin CFC KC 1156A). The curing reaction inducing laser beam 4 is a laser beam that is absorbed by the photocurable resin 6 and has an extremely weak light intensity. The reaction promoting laser beam 5 is a photocurable resin. This is a laser beam of another wavelength that is not absorbed by the resin 6.

Therefore, as shown in FIG. 2, only when the near-infrared laser beam 5 for promoting the reaction and the ultraviolet laser beam 4 for inducing the curing reaction are irradiated, the photocuring reaction (resin line pattern 7 ) Can be confirmed. Here, it is shown that the photo-curing reaction does not occur when only the curing reaction-inducing ultraviolet laser light 4 is irradiated, but the photo-curing reaction does not occur even when only the reaction-promoting near-infrared laser light 5 is irradiated.

[0030] This indicates that a spatially selective photopolymerization reaction can be induced by using two laser beams having different wavelengths.

Example 2

FIG. 3 is a system configuration diagram of a multi-beam micro structure stereolithography apparatus using a two-beam micro stereo modeling method according to a second embodiment of the present invention, and FIG. 4 is a glass illustrating a second embodiment of the present invention. It is a figure which shows the scanning electron microscope image of the photocurable resin which was spot-cured on the board | substrate.

In FIG. 3, 11 is an ultraviolet laser light source for inducing curing reaction, 12, 13, 16, 18, 19 are reflecting mirrors, 14, 15, 20, 21, 25 are lenses, and 17 is a near infrared for promoting reaction. Laser light source, 22 and 23 are dichroic mirrors, 24 is an objective lens (100x, NA: 1.3) 5), 26 is a CCD camera, 27 is a monitor, 31 is a cover glass, 32 is a photocurable resin, and 33 is a stage.

[0033] According to this example, an ultraviolet laser pulse (wavelength 355 nm, pulse width 0.5 ns) focused on the photocurable resin 32 dropped on the cover glass 31 by the objective lens 24 (curing reaction induction laser) When light (dotted line) is irradiated, photocuring occurs at the condensing position of the curing reaction-inducing ultraviolet laser light from the light intensity that reaches the threshold value of the photocuring reaction, as shown in Fig. 4 (a). Next, when continuous irradiation near-infrared laser light (wavelength 1064nm) (reaction promoting laser light) (solid line) (solid line) is also focused and irradiated together with ultraviolet laser light for curing reaction induction (dotted line), the left 3 in Fig. 4 (b). As shown in the column, the photo-curing reaction could be induced even with the UV laser light intensity for curing reaction induction that was so weak that the photo-curing reaction did not occur when only the curing reaction-inducing ultraviolet laser light (dotted line) was irradiated. . It was found that the photo-curing reaction with the intensity below the threshold value was not induced by irradiation with the curing reaction-inducing ultraviolet laser beam alone or the reaction promoting near-infrared laser beam alone.

[0034] As described above, FIG. 2 and FIG. 4 show that the present invention can impart space selectivity to the photopolymerization reaction.

FIG. 5 is a diagram showing a columnar microstructure manufactured according to the present invention. As is clear from this figure, a curing reaction-inducing ultraviolet laser beam and a reaction promoting near-infrared laser beam are used. The columnar microstructures 41 produced have a reduced level of excess growth in the horizontal and optical axis directions compared to the columnar microstructures 42 produced using only the curing reaction-inducing ultraviolet laser beam, and the molding accuracy is remarkably improved. It can be confirmed that there is an improvement.

[0036] As described above, according to the present invention, no photocuring reaction is induced !, extremely weak to the extent that ultraviolet laser light (a laser beam for inducing curing reaction) is applied at a light intensity in a photocurable resin. When the same spot is irradiated with a near-infrared laser beam (reaction promoting laser beam), the photocuring reaction can occur only in the vicinity of the focused spot of the ultraviolet laser beam.

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0038] According to the present invention, the following effects can be obtained. [0039] (1) Surplus growth in the horizontal direction and the optical axis direction is suppressed, and the modeling accuracy of the microstructure can be significantly improved.

[0040] (2) Nano-level three-dimensional spatial selectivity can be provided.

Industrial applicability

[0041] The multi-beam microstructure optical modeling method and apparatus using the different wavelength laser beam of the present invention can be expected to be used for manufacturing various micro devices (chemical chip, biochip, micromachine, etc.).

Claims

The scope of the claims

[1] A curing reaction-inducing laser beam is irradiated into the photocurable resin, and a reaction-promoting laser beam of another wavelength is superimposed on the curing reaction-inducing laser beam and irradiated into the photocurable resin. By doing so, a multi-beam microstructure optical modeling method using a different wavelength laser beam that induces a photocuring reaction only in the vicinity of the condensing spot where both laser beams overlap.

[2] In the multi-beam microstructure optical modeling method using the different wavelength laser beam according to claim 1, the curing reaction inducing laser beam is a laser beam absorbed in the photocurable resin. The reaction accelerating laser beam is a laser beam having a different wavelength that is not absorbed by the photocurable resin. Light beam microstructure optical modeling method.

[3] The multi-wavelength microstructure optical modeling method using the different wavelength laser beam according to claim 1 or 2, wherein the different wavelength laser has a nano-level three-dimensional spatial selectivity. Multi-beam micro structure stereolithography using light.

[4] In the multi-beam microstructure optical modeling method using the different wavelength laser beam according to claim 3, the intensity of the curing reaction inducing laser beam is approximately 0.038 to 0.076 W. Multi-beam microstructure optical modeling method using wavelength laser light.

[5] The multi-beam micro structure optical modeling method using the different wavelength laser beam according to claim 3, wherein the reaction promoting laser beam has a wavelength of approximately 1064 nm. Microstructure stereolithography method.

[6] The multi-beam micro structure using the different wavelength laser beam according to any one of claims 1 to 5, wherein the photocurable resin dripped on the glass substrate is used as the glass substrate. A multi-beam microstructure optical modeling apparatus using a different wavelength laser beam, wherein the laser beam for inducing curing reaction and the laser beam for promoting reaction are irradiated from the side.

[7] (a) No photo-curing reaction is induced! Extremely weak!

(b) means for irradiating the same spot as the curing reaction inducing laser light with the reaction promoting laser light in a state where the curing reaction inducing laser light is irradiated in the photocurable resin; (c) a multi-beam microscopic structure using a different wavelength laser beam, characterized by comprising a photo-curable resin capable of inducing a photo-curing reaction only in the vicinity of the condensing spot of the curing reaction-inducing laser beam. Stereolithography equipment.

[8] In the multi-beam microstructure optical modeling apparatus using the different wavelength laser beam according to claim 7, the curing reaction inducing laser beam has an intensity of approximately 0.038 to 0.076 W. A multi-beam microstructure optical modeling apparatus using different wavelength laser light characterized by:

[9] In the multi-beam microstructure optical modeling apparatus using the different wavelength laser beam according to [7], the reaction promoting laser beam has a wavelength of approximately 1064 nm. Multi-beam micro structure stereolithography equipment.

[10] In the multi-beam microstructure optical modeling apparatus using the different wavelength laser beam according to [7], the photocurable resin is a photocurable resin dropped on a glass substrate, and the glass A multi-beam fine structure optical modeling apparatus using a different wavelength laser beam, wherein the curing reaction inducing laser beam and the reaction promoting laser beam are irradiated from the side of the substrate.

[11] In the multi-beam microstructure object stereolithography apparatus using the different wavelength laser beam according to any one of claims 7 to 10, the photocurable resin is an acrylic photocurable resin. A multi-beam microstructure optical modeling apparatus using different wavelength laser light, characterized by