JPH0820072A - Minute area photosensitizing method, optical shaping method using the same and photosensitive substance-processing apparatus - Google Patents

Abstract

PURPOSE:To provide a photosensitizing method for photosensitizing a minute area exceeding the throttling limit due to the diffraction of light, an optical shaping method using the same and a processing apparatus capable of producing a minute structure. CONSTITUTION:The minute area of a photosensitive substance capable of being changed in its physical properties by light reaction due to the irradiation with light of a specific wavelength region is photosensitized. A photosensitive substance film 1 is placed on a work table 2 and light on a wavelength side longer than a wavelength starting light reaction is allowed to be incident on the interface where a minute are a to be photosensitized is present of the photosensitive film so as to satisfy a total reflection condition. The pointed part 4a of a probe 4 formed from a molecule having non-linear susceptibility of at least one of secondary and tertiary ones in the wavelength region of the light is positioned on the surface of the photosensitive substance film or in the vicinity thereof to reflect the higher harmonic of the incident point to induce light reaction in the minute area. This operation is performed with respect to each point of an objective shape to form a latent image which is, in turn, developed to obtain a minute structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive method suitable for exposing a minute region of a photosensitive material, particularly, a minute region exceeding a limit of narrowing down due to diffraction, and a photolithography using the same. A method and a photosensitive material processing apparatus.

[0002]

2. Description of the Related Art In recent years, minute structures such as micromachines have been proposed. Since these microstructures are too small, how to manufacture components for constructing them, such as gears, is a problem. As one of such manufacturing methods, there is a stereolithography technique using a photocurable resin. This stereolithography technology sweeps the laser light focused on the surface of the photocurable resin solution,
After that, the exposed resin surface was further covered with a new resin solution layer, and the sweeping of the laser beam was repeated to form an object having an arbitrary shape.

[0003]

In the conventional stereolithography technique, the laser beam is focused on the surface of the resin solution by using a lens or a curved mirror. In general, an electromagnetic wave having an arbitrary wavelength (wavelength λ) emitted from a point light source is spotted by a spot diameter (λ
/ 2 ・ NA) can be narrowed down. However, narrowing the spot diameter smaller than this is limited because it is affected by light diffraction. Therefore, there is a limit due to diffraction in narrowing down electromagnetic waves such as light. Therefore, it was not possible to form a minute three-dimensional structure that exceeds the limit due to the diffraction of light. However, in recent years
It is desired to manufacture a finer structure that exceeds the limit of narrowing down due to light diffraction, and development of a molding technique capable of coping with the demand is demanded.

Therefore, the present invention provides a photosensitive method capable of exposing a microscopic area exceeding the limit of focusing due to light diffraction, a stereolithography method using the same, and a limit of limiting due to light diffraction. The present invention provides a processing apparatus capable of manufacturing a fine structure exceeding the limit.

[0005]

In order to solve the above-mentioned problems, according to the present invention, a photosensitive material capable of changing its physical properties by a photoreaction caused by irradiation of light in a specific wavelength range, has its minute regions A method of exposing light so that light having a wavelength longer than the wavelength at which the photosensitive substance starts a photoreaction is satisfied with respect to the interface of the photosensitive substance in which a minute region to be exposed exists. And a sharp portion of the probe formed of a molecule having a nonlinear susceptibility of at least one of the second order and the third order in the wavelength range of the light is positioned on or near the surface of the photosensitive substance. Then, a fine area sensitizing method is provided in which a harmonic of incident light is radiated at the sharp portion to induce a photoreaction at the portion.

According to another aspect of the present invention, a photosensitive material whose physical properties can be changed by irradiation with light in a specific wavelength range is irradiated with light in the wavelength range at a target position,
In a stereolithography method of forming a target shape by inducing a photoreaction and then developing, (A) forming a film of the photosensitive substance, and (B) in the wavelength range of the light, secondary and The sharp parts of the probe formed of molecules having at least one of the third-order non-linear susceptibility are sequentially positioned at the site to be exposed, and when the sharp parts are present at the site to be exposed, the sharp parts are exposed to the light. The light having a wavelength longer than the wavelength at which the photoreaction is initiated is incident on at least one flat surface of the film of the photosensitive material so as to satisfy the condition of total reflection while being positioned on or near the surface of the photosensitive material. Then, a harmonic wave of incident light is radiated at the sharp portion, and a photoreaction is induced in the portion to form a latent image of a target shape, and (C) the latent image is developed to obtain a target image. Characterized by getting shape Optical modeling method of are provided.

The latent image of (B) is formed, for example, by locating the sharp portion of the probe on or near the surface of the photosensitive material and scanning it in sequence so that the sharp portion is exposed to light. When present, this can be done by injecting light that causes the above-mentioned total internal reflection. Further, in forming the latent image of (B), light having a wavelength longer than the wavelength at which the photoreaction starts is incident on at least one flat surface of the film of the photosensitive material so as to satisfy the condition of total reflection. In this state, the sharp portion of the probe is positioned above the surface of the photosensitive substance and sequentially scanned, and when the sharp portion is present at the site to be exposed, the sharp portion is formed on the surface of the photosensitive substance. It can be carried out by arranging it on the surface or near the surface and radiating a harmonic wave of incident light at the sharp point to induce a photoreaction at the site.

Further, the stereolithography method of the present invention is based on the above (A).
The processing of (B) may be repeated for each layer, films of a photosensitive material may be sequentially laminated, and a latent image formed over a plurality of layers may be developed to obtain a target shape. .
This makes it possible to form a three-dimensional structure, that is, a structure having a thickness larger than the film thickness of the photosensitive material that can be exposed at one time.

Further, according to another aspect of the present invention, a photosensitive substance whose physical properties can be changed by irradiating light in a specific wavelength range is irradiated with light in the wavelength range to a target position, and light is emitted. In a photosensitive material processing apparatus that forms a target shape by inducing a reaction and then developing, a transparent material in at least one region on the longer wavelength side than the wavelength that induces a photoreaction in the photosensitive material. In a workbench composed of, a light source that emits light on a longer wavelength side than a wavelength that starts a photoreaction, and a wavelength range of light emitted from the light source,
A probe formed of a molecule having at least a second-order and a third-order non-linear susceptibility and having a sharp point at at least one position, and for displacing the probe three-dimensionally above a photosensitive substance A displacement mechanism, and the light source is arranged at a position where a light beam is incident on the workbench so as to satisfy the condition of total reflection with respect to at least one flat surface of the photosensitive material held on the workbench. ,
The displacing mechanism is characterized in that the sharp portion of the probe is located on or near the surface of the photosensitive material, and a harmonic of incident light can be radiated at the sharp portion. A processing device is provided.

In each of the above aspects, the sharpened portion may have a harmonic radiation surface smaller than the limit of focusing due to diffraction of light.

[0011]

According to the present invention, the light having a wavelength longer than the wavelength at which the photoreaction is initiated is incident on at least one flat surface of the photosensitive material so as to satisfy the condition of total reflection, and the surface of the photosensitive material is irradiated. Generate an evanescent wave from. Next, a probe formed of a molecule having a nonlinear susceptibility of at least one of the second order and the third order in the wavelength range of the light and having a sharp point at at least one position is provided on the surface or surface of the photosensitive substance. Position it in the vicinity. As a result, polarization of the probe sharp portion is excited by the evanescent wave. In this case, the size of the sharp surface of the probe is sufficiently smaller than the coherent length on the tip side, and is the size of a portion having a volume capable of generating a sufficient amount of harmonics for exposing the photosensitive material. Decided. This size can be made sufficiently smaller than the limit of narrowing down by diffraction, that is, about 1/2 of the wavelength of the light source (here, the wavelength of the harmonic wave).

On the other hand, from the tip of the excited probe,
A harmonic of the excitation light, for example, a second harmonic, is generated. Since the second harmonic is generated from a region smaller than the wavelength of light, so long as the molecules that make up the probe have a second-order nonlinear susceptibility, even if phase matching is not performed, If so, the second harmonic is generated. Moreover, it can be generated from a region smaller than the wavelength.

In this state, when the probe scans the surface of the resin, the ultraviolet curable resin is exposed to light by the light emitted from the tip of the probe, and the exposed region can be made sufficiently smaller than the wavelength. Therefore, according to the apparatus of the present invention, resin processing can be performed in a region smaller than the photosensitive wavelength.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for exposing a fine area, the method for stereolithography and the apparatus for processing a photosensitive material according to the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows the outline of the configuration of the processing apparatus used in this embodiment. In FIG. 1, the apparatus of the present embodiment includes a work table 2, a support table 7 for fixedly supporting the work table 2, and a laser which is a light source for causing a light beam for causing total reflection to enter the work table 2. 3, a probe 4 placed above the work surface 2a for performing work by placing the work material 1 on the work table 2, an actuator 5 for displacing the probe 4, and above the work surface 2a. And a position detection device 9 for confirming that the tip of the probe 4 has entered the evanescent region.

The workbench 2 is made of a transparent material in at least one region on the wavelength side longer than the wavelength that induces a photoreaction in the material 1 to be processed. For example, it is formed of glass. More specifically, in this embodiment, silicate glass is used. Further, the workbench 2 of this embodiment is formed in a right-angle prism shape. The workbench 2 has a bottom surface of the right-angled prism as a work surface 2a on which the material 1 to be processed is placed. At the outer edge of the work surface 2a,
Frame 2 for preventing the work material 1 from leaking out
d is placed. Further, a surface corresponding to one of the two vertical sides of the right-angle prism is an incident surface 2b for inputting a processing light beam, and a surface corresponding to the other side is an emitting surface 2c for emitting totally reflected light. There is. Working surface 2a, incident surface 2
The b and the emitting surface 2c are each subjected to optical polishing.

The support base 7 is a base for fixing the work base 2, and is fixed to the triaxial movable stage 8. This 3
The work table 2 can be largely displaced in three dimensions by the axially movable stage 8. The triaxial movable stage 8 is further provided with a three-dimensional drive mechanism 12, which is driven by displacement. The three-dimensional drive mechanism 12 is a control device 1 described later.
Controlled by 0. In addition, the 3-axis movable stage 8
In this embodiment, it is placed on an optical vibration isolation table (not shown).

The laser 3 as the light source is determined in consideration of the photoreaction characteristics of the material 1 to be processed, particularly the spectral characteristics. For example, when a UV-sensitive resin is used as the material to be processed 1, the laser oscillation wavelength is, for example, 400 nm or more 8
It is preferably in the range of 00 nm or less. In this embodiment, a mode-locked dye laser is used. More specifically, (Rhodamine 6G, wavelength 600 nm, repetition 4M
A mode-locked dye laser having a frequency of Hz and a peak power of 10 kW is used. Of course, the present invention is not limited to this. Further, the laser 3 causes the light beam to be incident on the incident surface 2b of the workbench 2a so that the total reflection condition is satisfied with respect to at least one flat surface of the material 1 to be processed held on the workbench 2a. Will be placed. This flat surface is usually one of the surfaces of the material 1 to be processed which is parallel to the work surface 2a and serves as an interface with air. The laser 3 has a driving device (not shown), and the operation is performed by the driving device based on a command from the control device 10 described later. The reason for forming a flat surface is that the generation of light scattering at the interface is suppressed and a uniform evanescent wave is obtained. In particular, when a three-dimensional structure to be described later is formed, a plurality of layers of the material to be processed are laminated, so that each layer, particularly the lower layer, is desired to be flat.

The probe 4 is formed of a molecule having a second-order or third-order nonlinear susceptibility in the wavelength range of the light emitted from the laser 3. Then, it has a shape having a sharp portion 4a at least at one position, more specifically, at the tip. Specifically, for example, a β-barium borate (BBO) crystal whose tip is sharpened by polishing is used.

The actuator 5 is a drive device for driving the probe 4 on the surface of the material 1 to be processed or in the vicinity thereof so as to be displaced three-dimensionally and arbitrarily. For example, it is composed of piezoelectric ceramics. The actuator 5 is
In this embodiment, it is fixed to an optical vibration isolation table (not shown). The actuator 5 is a device for driving the actuator 5 and is controlled by the controller 10,
A drive circuit 11 that outputs a drive voltage for driving the actuator 5 is further included.

The control unit 10 has a central processing unit (CPU) 10a for executing control and a memory 10b. The memory 10b stores the program of the CPU 10a and three-dimensional data representing the shape of the target structure. The CPU 10a obtains the address at which the sharp portion 4a of the probe 4 should be located based on this three-dimensional data, further obtains the drive voltage based on the relationship between the drive voltage of the actuator 5 and the displacement stroke, and drives the result. Send to circuit 11. Further, the control device 10 controls the driving of the three-dimensional drive mechanism 12 and the laser 3 in addition to the probe 4. Information from the optical sensor 9b is input to the control device 10 as described later. This information is available in probe 4
Will be referred to when controlling the driving of the laser and the driving of the laser 3.

The controller 10 can be connected to a computer system (not shown) such as a workstation, and can exchange information with an external computer system. That is, the shape data of the structure, various instructions, and the like are received. In addition, it is possible to output information indicating the processing state.

The micro dispenser 6 is located above the work surface 2a of the work table 2 and drops the material 1 to be processed on the work surface 2a. Further, the micro dispenser 6 is provided with a supply amount control device (not shown) and can control the supply amount of the material 1 to be processed. That is, as a result, the thickness of the amount of material to be processed to be processed on the first floor can be set to a specific thickness.

The position detecting device 9 comprises a convex lens 9a and an optical sensor 9b for detecting the light emitted from the sharp portion 4a of the probe 4 via the lens 9a. As the optical sensor 9b, for example, a semiconductor optical sensor such as a photodiode or a phototransistor is used. With this position detector 9, it is possible to confirm that the sharp portion 4a of the probe 4 has entered the evanescent region. That is, the output of the optical sensor 9b is sent to the control device 10, where the position of the sharpened portion 4a of the probe 4 is detected. Then, based on this information, the control device 10
Controls the drive circuit 11 to control the sharp portion 4a of the probe 4.
To the appropriate position.

Next, the operation of this embodiment will be described.
In the description, first, the case of exposing a minute region of a material to be processed is described, and then the case of manufacturing a two-dimensional microstructure, and further, a three-dimensional microstructure, that is, a three-dimensional microstructure. The case of making a body will be described.

Generally, in stereolithography, the material to be processed is
A substance whose properties change when irradiated with light, that is, a photosensitive substance is used. As a photosensitive material, in this embodiment,
A photocurable resin that causes a photoreaction at a wavelength shorter than the wavelength of irradiation light, that is, a wavelength of a harmonic wave emitted from the probe is used. In addition, this substance is applied to the work surface 2 a of the work table 2.
It is preferable to have a refractive index that is likely to cause total internal reflection in the state of being placed in the atmosphere. For example, a substance having a refractive index similar to that of the workbench 2 is preferable. Therefore, in this embodiment,
A generally well-known ultraviolet curable resin, more specifically, an ultraviolet curable acrylic resin is used. This resin starts to cure upon irradiation with ultraviolet light having a wavelength of 400 nm or less. Examples of this type of UV-curable acrylic resin include OPTOMER, trade name, manufactured by Asahi Denka, and Fujihard, trade name, manufactured by Fujikura Kasei.

First, the photocurable resin, which is the amount of the material to be processed, is dropped by the microdispenser 6 onto the work surface 2a of the workbench 2 in a predetermined film thickness (300 nm in this embodiment). To do. By evaporating the solvent of the resin solution,
The resin has an appropriate viscosity.

Next, the light on the longer wavelength side than the wavelength at which the photoreaction starts of the photocurable resin is totally reflected on at least one flat surface (the upper surface in this embodiment) of the photosensitive material film. It is incident so as to satisfy the conditions. Specifically, a mode-locking dye laser (Rhodamine 6G, wavelength 600 nm, repetition 4 MHz, peak power 10 KW) 3 is used. At this time, the control device 10 controls the optical sensor 9b of the position detection device 9
While monitoring the output of, the tip of the probe 4 is brought close to the resin surface. At this time, the optical output of the laser 3 is made sufficiently low. That is, although the measurement of the optical sensor 9b is possible,
The light output is such that harmonics generated at the sharp portion 4a of the probe 4 do not sensitize the photosensitive material.

In general, when an object is brought closer to the evanescent wave region, the intensity of scattered light from the object exponentially increases as the distance from the surface becomes shorter. FIG. 2 shows the relationship between the drive voltage of the actuator 5 that drives the probe 4 and the output from the optical sensor 9b. It can be seen that the scattered light intensity is saturated when the tip of the probe 4, that is, the sharp portion 4a reaches the resin surface. The drive voltage for moving the probe 4 in the direction perpendicular to the surface is set with the voltage A as a guide according to the requirements of the material to be processed.

After that, the controller 10 makes the laser output sufficiently high. That is, it is exposed. The exposure time varies depending on the resin and the laser output, but is about 60 seconds in this embodiment. Control device 10
At this time, using the scattered light intensity B at the voltage A as a guide, the drive voltage is controlled so that a constant scattered light intensity is always obtained. Further, the output of the laser light can be modulated or the distance from the surface can be modulated, if necessary.

In this way, a photoreaction is caused by the scattered light of the second harmonic on the target shape portion of the resin film, and a latent image of a microstructure can be formed. In this case, the ultraviolet curable resin is used as the sharp portion 4 of the probe 4.
The light is emitted by the light emitted from a, and the light-sensitive region can be made sufficiently smaller than the wavelength by reducing the sharp portion 4a and bringing it closer to the resin. Therefore,
According to this embodiment, it is possible to expose a region smaller than the photosensitive wavelength.

In order to expose a specific area of the photo-curable resin to light, a three-dimensional address of the area is controlled by the controller 10.
Give to. Based on this address, the control device 10
A signal necessary for displacing the sharp portion 4a of the probe 4 to the position indicated by the address is generated and sent to the drive circuit 11. The drive circuit 11 drives the actuator 5 based on this. Thereby, the sharp portion 4a of the probe 4
Will be displaced to the addressed location.

Next, a two-dimensional microstructure, that is,
The production of a microstructure composed of one layer of photocurable resin film will be described.

Also in this example, the photocurable resin film (workpiece material) 1 is formed in the same manner as described above. However, the above-described exposure of a minute area is an example in which only a target point is exposed. As in the present example, in order to form a two-dimensionally shaped structure, the entire two-dimensionally partitioned shape may be exposed. For that purpose, the photosensitive processing of the minute area may be performed at each point in the target shape. That is, the sharp part of the probe is sequentially positioned at the site to be exposed,
When the sharp portion is present at a site to be exposed to light, the sharp portion is positioned on or near the surface of the photosensitive substance, and the light having a wavelength longer than the wavelength at which the photoreaction is started is exposed to the photosensitive substance. By injecting at least one flat surface of the film so as to satisfy the condition of total reflection, radiating a harmonic wave of the incident light at the sharp portion, exposing for a certain period of time, and inducing a photoreaction at the site. , Form a latent image of the desired shape.

In this photosensitive method, there are, for example, three methods for forming a two-dimensional latent image. First, the sharp portion 4a of the probe 4 is positioned on or near the surface of the photosensitive material and sequentially scanned, and when the sharp portion 4a is present at the site to be exposed, the above-mentioned total reflection occurs. This is a method of injecting light. Secondly, the probe 4 is made incident so that the total reflection condition is satisfied.
The sharp portion 4a of the photosensitive material is positioned above the surface of the photosensitive substance and sequentially scanned, and when the sharp portion is present at a portion to be exposed, the sharp portion 4a is on or near the surface of the photosensitive material. It is a method of locating. Thirdly, the sharp portion 4a of the probe 4 is positioned on or near the surface of the photosensitive material while being incident so as to satisfy the conditions for total reflection, and the interior of the target shape is sequentially scanned. Is the way.

In any of these methods, it is necessary to find the exposure position based on the shape to be exposed. This is performed by the control device 10. That is, the control device 10
The address of the minute area to be exposed is obtained based on the shape data of the minute structure to be formed. Then, the probe 4 and the laser 3 are controlled based on this address. In addition, as shown in FIG. 2, the control device 10 refers to the signal from the optical sensor 9b and refers to the scattered light intensity B at the voltage A.
As a guide, the drive voltage of the probe 4 is always controlled so that a constant scattered light intensity can be obtained. Further, the output of the laser light can be modulated or the distance from the surface can be modulated, if necessary. When determining the exposure position, the origins of the coordinate system of the workbench 2 and the coordinate system of the probe 4 are aligned. At this time, changing the position of the workbench 2
This is performed by driving the triaxial movable stage 8 by the three-dimensional drive mechanism 12.

First, the exposure by the first method will be described. In this method, the control device 10 controls the drive circuit 11 to sweep the probe 4 on the resin plane by the actuator 5. Then, when the sharp portion 4a of the probe 4 is located at the address of the minute region to be exposed, the movement of the probe 4 is stopped, the laser 3 is activated, and light irradiation is performed for a predetermined time. As a result, the harmonics are radiated from the sharp portion 4a of the probe 4 to expose the minute area at that position. By performing this for each minute area, all areas in the two-dimensional shape are exposed.

In the second method, the laser 3 is activated to continuously irradiate light. Meanwhile, the control device 10 controls the drive circuit 11 to sweep the probe 4 on the resin plane by the actuator 5. Then, when the sharp portion 4a of the probe 4 is located at the address of the minute region to be exposed, the movement of the probe 4 is stopped, and the sharp portion of the probe 4 is brought close to the photocurable resin film to be predetermined. Hold in that position for hours. As a result, the harmonics are radiated from the sharp portion 4a of the probe 4 to expose the minute area at that position. By performing this for each minute area, all areas in the two-dimensional shape are exposed.

In the first and second methods described above, the probe 4 is raster-scanned, and when the point is within the target shape, the probe 4 is stopped and exposure is performed. For this, the third
In the method (1), the probe 4 is scanned only within the target shape, and when the point is within the target shape, the probe 4 is stopped, and exposure is performed in the vicinity of the photocurable resin film.

That is, according to the third method, the probe 4 is moved to the starting point in the target shape in accordance with the instruction from the control device 10, and is brought close to the resin film at that position. In this state, the laser 3 is activated to perform exposure for a certain period of time. Then, in accordance with a predetermined scanning order, the probe is sequentially moved to another minute region, stopped at each point, and exposure is performed.

In this way, a photoreaction is caused by the scattered light of the second harmonic on the target shape portion of the resin film to form a latent image of the microstructure. Then, this is developed. That is, the uncured portion is removed with an appropriate solvent or developing solution. After that, the obtained microstructure is attached to the work surface 2a of the workbench 2 using microtweezers or a filter.
Separate from.

Next, production of a three-dimensional microstructure according to this embodiment will be described.

In order to manufacture a three-dimensional microstructure, first, the height direction thereof is divided into widths that can be formed by one layer of photocurable resin, and the shape data of the planar shape is formed for each layer. To create. Then, the photo-curable resin film 1 corresponding to the first layer is formed, and a latent image is formed on the photo-curable resin film 1 in the same procedure as in the above-mentioned two-dimensionally shaped microstructure.
In the case of a two-dimensional structure, development is performed after forming a latent image. However, in the case of a three-dimensional structure, after forming a latent image, a photo-curable resin film of the next layer is formed thereon, and a latent image having a two-dimensional shape is formed for this. . This is repeated for the required number of layers to form a three-dimensional latent image. Then, development is performed to form a three-dimensional structure. This three-dimensional structure, when washing the uncured resin portion with an appropriate solvent, divide it from the solution by a filter,
Take it out.

FIG. 3 schematically shows the process of forming a three-dimensional microstructure in three dimensions. That is, in FIG. 3 (A), the photocurable resin film first layer 1a is formed on the work surface 2a of the workbench 2, and the sharp portion 4a of the probe 4 is brought close to a specific region thereof to expose it to light. , A state in which the photosensitive portion 1a 'is formed is shown. In FIG. 3B, the second layer 1b is further formed on the first layer 1a, and the sharp portion 4a of the probe 4 is brought close to and scanned with respect to a specific region of the second layer 1b. And exposed to light to form the photosensitive portion 1b '.
FIG. 3C shows a state in which an unexposed portion of the photo-curable resin film is removed by a development process thereafter to obtain a desired three-dimensional microstructure including the exposed portions 1a ′ and 1b ′. .

Next, an experimental example relating to the fabrication of the microstructure according to this embodiment will be described.

(Experimental Example) As the photocurable resin, an ultraviolet curable acrylic resin (Optomer, trade name, manufactured by Asahi Denka Co., Ltd.) was used. The workbench 2 is made of silicate glass. A mode-locking dye laser (Rhodamine 6G, wavelength 600 nm, repetition rate 4 MHz, peak power 10 KW) was used as the laser. As probe 4, β
-A barium borate (BBO) crystal whose tip was sharpened by polishing was used. And, the photosensitive resin,
Apply to the work surface 2a of the work table 2 with a thickness of 300 nm,
The probe 4 was fixed on the surface of the photocurable resin and exposed for 60 seconds while controlling the scattered light intensity to be 75% of B in FIG. 2 using the above dye laser and probe. After repeating the same process a plurality of times at different points on the surface, the uncured resin was washed off with acetone, and the cured product remaining on the work surface 2a of the workbench 2 was observed with an electron microscope. A plurality of granular fallouts of 0.3 to 0.5 micron were confirmed.

According to the above-described embodiment, it is possible to expose a minute area and a two-dimensional shape, and as a result, a minute three-dimensional structure having an arbitrary shape sufficiently smaller than the photosensitive wavelength of the photocurable resin is formed. It became possible to do. Although these microstructures can be widely used, they are particularly important as parts of micromachines, for example, microrobots.

In the embodiments described above, the ultraviolet curable acrylic resin is used, but other photocurable materials, photodecomposable materials, photosublimation materials, photochargeable materials and the like can also be used. In this embodiment, it is necessary to select the laser and its oscillation wavelength at that time. In this embodiment, the dye laser is used as the light source, but almost all lasers can be used as the laser. Further, a light source other than a laser, an incoherent light source such as an LED, a flash lamp, an arc lamp, or the like can be used.

As the probe 4, almost all non-linear optical materials known to date can be used, though there is a limitation depending on the wavelength of the laser. Further, in this embodiment, the material having the second-order nonlinear susceptibility is used as the probe, but the material having the third-order nonlinear susceptibility can also be used as the probe. Further, in this embodiment, the photosensitive resin spread on the workbench is processed, but it is also possible to adopt a structure in which the photosensitive material itself also serves as a workbench.

Further, according to the present invention, one workbench can be provided on one workbench.
It is also possible to form a film of the photosensitive material and to form a plurality of the same structures at a plurality of locations on this film. Also, different structures may be formed.

[0051]

According to the present invention, it is possible to expose a minute area exceeding the limit of narrowing down due to diffraction of light. Further, this photosensitive method can be used to form a two-dimensional microstructure and a three-dimensional microstructure.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an embodiment of an optical resin processing device of the present invention.

FIG. 2 is a graph showing the relationship between probe driving voltage and scattered light intensity according to the present invention.

FIG. 3 is an explanatory view schematically showing a process of forming a three-dimensional three-dimensional microstructure, which is an embodiment of the present invention.

[Explanation of symbols]

1 ... Material to be processed (photosensitive substance / photocurable resin, 2 ... worktable, 2a ... work surface, 3 ... laser light, 4 ... probe, 4a
... pointed part, 5 ... actuator, 6 ... photocurable resin dropping means, 7 ... support base, 8 ... lens, 9 ... position detector, 10 ...
Control device.

Claims (6)

[Claims] 1. A photosensitive substance whose physical properties can be changed by a photoreaction by irradiation with light in a specific wavelength range,
A method of exposing the minute region to light, wherein light having a wavelength longer than a wavelength at which the photosensitive substance starts a photoreaction is totally reflected on an interface of the photosensitive substance in which the minute region to be exposed exists. The probe is made incident so as to satisfy the conditions, and the sharp portion of the probe formed of a molecule having at least one of second-order and third-order nonlinear susceptibility in the wavelength range of the light is provided on the surface of the photosensitive material or on the surface. A method for exposing a minute area, which is characterized in that it is positioned in the vicinity and a harmonic of incident light is radiated at the sharp portion to induce a photoreaction at the portion. 2. A photosensitive material, the physical properties of which can be changed by irradiation with light in a specific wavelength range, is irradiated with light in the wavelength range at a target position to induce a photoreaction, and then development is performed. Thus, in the stereolithography method for forming a desired shape, (A) a film of the photosensitive material is formed, and (B) at least one of a second-order and a third-order nonlinear susceptibility in the wavelength range of the light. The sharp points of the probe formed of the molecule have are sequentially positioned at the site to be exposed to light, and when the sharp parts are present at the site to be exposed to light, the sharp points are positioned on or near the surface of the photosensitive substance. At the same time, light on the longer wavelength side than the wavelength at which the photoreaction is initiated is made incident on at least one flat surface of the film of the photosensitive material so as to satisfy the condition of total reflection, and the harmonics of the incident light at the sharp portion. Radiate the waves By inducing a photoreactive at the site, to form a latent image of the desired shape, (C) developing the latent image, an optical molding method characterized by obtaining the desired shape. 3. The latent image of (B) according to claim 2, wherein the sharp portion of the probe is positioned on or near the surface of the photosensitive substance and sequentially scanned, and the sharp portion is formed. A stereolithography method, characterized in that, when present in a region to be exposed, the light that causes the above-mentioned total reflection is made incident. 4. The formation of the latent image of (B) according to claim 2, wherein the light on the longer wavelength side than the wavelength at which the photoreaction starts is
With respect to at least one flat surface of the film of the photosensitive material, the sharp portion of the probe is positioned above the surface of the photosensitive material while being incident so as to satisfy the total reflection condition, and the scanning is performed sequentially, When the sharp portion is present at the portion to be exposed to light, the sharp portion is positioned on or near the surface of the photosensitive substance, and the sharp portion emits a harmonic wave of incident light to cause photoreaction to the portion. A stereolithography method characterized by inducing. 5. The method according to claim 2, 3 or 4, wherein the treatments (A) and (B) are repeated for each layer so that a film of a photosensitive material is sequentially laminated to form a plurality of layers. A stereolithography method comprising developing a latent image to obtain a desired shape. 6. A photosensitive material, the physical properties of which can be changed by irradiation with light in a specific wavelength range, is irradiated with light in the wavelength range at a target position to induce a photoreaction, and then development is performed. In the photosensitive material processing device for forming a desired shape, a workbench made of a transparent material in at least one region on the longer wavelength side than the wavelength that induces a photoreaction in the photosensitive material, And a molecule having a non-linear susceptibility of at least any of the second order and the third order in the wavelength range of the light emitted from the light source. A probe having a sharp portion at least at one place and a displacement mechanism for three-dimensionally displacing the probe above the photosensitive material, wherein the light source is a photosensitive material held on a workbench. Few The light beam is placed at a position where it is incident on the work table so that the total reflection condition is satisfied for one flat surface, and the displacement mechanism positions the sharp portion of the probe on or near the surface of the photosensitive material. In addition, the photosensitive material processing apparatus is characterized in that it can emit a harmonic wave of incident light at the sharp portion.